Improving Quality of Service in GSM By Reducing Probability of Call Blocking Through Network Dimensioning Using Erlang B Model and Congestion Control Algorithm
Call blocking probability is a key performance metric for any telecommunication protocol.
Unexpectedly, the level of patronage being experienced in Global System for Mobile Communication (GSM) in
Nigeria is overwhelming. This is as a result of freedom of calling from anywhere at any time and clarity of the
voice enjoyed in GSM since it is on a digital technology platform. This has brought a lot of congestion in the
network resulting in poor services by the operators. This research has developed a control algorithm for the
management of the congestion experienced in the GSM network in Nigeria. It explores the use of Erlang-B in
determining the appropriate probability level for some range of subscribers. Thereafter, when there is
congestion, block time sharing, dynamic allocation without time slicing, dynamic allocation time slicing with
signal sensing, frequently recent call allocation, and priority allocation algorithms were developed to manage
the congestion. Furthermore, a hybrid algorithm was developed that integrates all the algorithms together in
other to manage the congestion considering all the strengths and constraints of each algorithm. If the
recommended congestion management algorithm is followed comprehensibly, the congestion problem on the
GSM network will be reduced drastically which in turn reduces call block. Also, from the research conducted by
NCC and others in quest for ameliorating the call block problem, it was noted that from the average number of
subscribers that dialed up to three or more times before getting connected, 58% of call blocking rate was
recorded which after using more number of timeslots (which depicted more available channels) in this work was
reduced as showed in the simulation results and will also be reduced the more using the developed congestion
control algorithm technique. The simulation codes and program are shown on the appendix in chapter five.
Marketing implications of call drops for the patronage of gsm services in nig...Alexander Decker
This study examined the marketing implications of call drops for GSM services in Nigeria. A survey was conducted with 384 respondents from MTN, GLO, and Airtel networks in Imo and Abia States. The study found that call drops negatively impact customer loyalty, satisfaction, and patronage of GSM services. Factors like network quality, pricing, coverage, and call completion rates were found to influence customer choice of networks. Customers reported feeling dissatisfied when calls repeatedly dropped. The researchers recommended that the government and regulators more closely monitor operators' quality of service and pricing, and that network infrastructure be expanded to reduce call dropping, especially in rural areas.
Site specific assessment of node b using key service quality indicators over ...Alexander Decker
This document summarizes a study that assessed the quality of service of three Node B base stations (BEN 035, BEN026, and BEN 098) on a 3G/UMTS network in Benin City, Nigeria through outdoor drive-test measurements. Key quality indicators such as received signal code power (RSCP), energy per chip to total received power ratio (Ec/Io), and received signal strength indicator (RSSI) were measured along drive routes near each base station. The results found that BEN 035's Ec/Io range indicates it can support more subscribers, but tuning may be needed to reduce interference. QoS was very poor near BEN026, likely causing data access issues for users
SAMENA Response to Iraq CMC fixed wireless consultationroberto ercole
The document summarizes SAMENA's response to Iraq's Communications & Media Commission regarding proposed fixed wireless broadband licensing and spectrum allocation. Key points:
1. SAMENA believes licenses should allow both fixed and mobile broadband to promote broader access and a viable business case. Restricting licenses to just fixed use may undermine commercial deployment.
2. There may be cross-border interference issues, particularly with neighboring countries using all TDD networks in the 2.6GHz band. Band plans should be harmonized as much as possible to minimize interference.
3. The proposed amount of spectrum for fixed wireless may exceed market needs. A combined mobile/fixed approach could better support broadband access through economies of scale for operators.
GSM QUALITY OF SERVICE PERFORMANCE IN ABUJA, NIGERIAIJCSEA Journal
There has been tremendous growth in Global System for Mobile (GSM) services in Nigeria in the last two decade. The rapid development of GSM telecommunication industries have given rise to need for how the
GSM services are delivered to customers efficiently. This paper is on GSM quality of service (QoS) performance in, Abuja Nigeria. The study investigates network transmission impairment and offers some useful remedies. The method involved use of Sony Ericson W-995 phone to gather data on physical network impairments in selected densely populated areas of Abuja. The data obtained were from four major GSM
service providers MTN, Etisalat, Glo and Airtel. Assessment in terms of Key Performance Indicator (KPI) using Transmission Environment Monitory System (TEMS) Discovery professional software carried out on the networks under test. The results obtained from the analysis indicated that QoS performance of Airtel is slightly better than the other three GSM services providers tested within Nyanyan, Gwagwalada, and Wuse
areas in Abuja.
3G, or third generation mobile telecommunications, supports information transfer rates of at least 200 Kbit/s and provides higher speeds than previous 2G technologies. The two main 3G standards are UMTS, used primarily in Europe and standardized by 3GPP, and CDMA2000, used in North America and South Korea. 3G enabled rapid growth in data traffic such as text and web access through mobile phones, with projections of 50% of total mobile traffic consisting of data within 5 years of its introduction. It also facilitated increased mobile internet and device penetration.
The quality of service of the deployed LTE technology by mobile network opera...IJECEIAES
In this study, the real-world performance analysis of four Nigerian mobile network operators (MNOs), namely MTN, GLO, Airtel, and 9Mobile longterm evolution (LTE) cellular network, were analyzed and compared. The Nigerian MNOs utilize 5 MHz, 10 MH, and 20 MHz channel bandwidths based on third-generation partnership project’s (3 GPPs) recommendation. The presented analysis shows the uplink (UL), and downlink (DL) throughputs gaps in mobility condition as well as other LTE’s system quality of service (QoS) key performance indicators (KPI’s) of: Connection drop rate, connection failure rate, peak physical downlink throughput, minimum radio link control (RLC) downlink throughput threshold and latency are not strictly followed. The reason may be due to a lack of regulatory oversight enforcement. The comparative studies showed that MTN provides the best QoS. The introduction of novel LTE QoS metrics herein referred to as national independent wireless broadband quality reporting (NIWBQR) is the significant contribution of this study. The goal of this study is to show the quality of the network as it affects the user's experience. Important observation showed that all the MNOs are not adhering to the 3 GPPs specified user plane latency of 30 ms and control plane latency of 100 ms, respectively, which makes video streaming and low latency communication a near-impossible task.
The document is a training report submitted by Atul Sharma summarizing his internship at Idea Cellular pvt ltd. It provides an overview of GSM technology including its history and advantages. It describes the three subsystems of GSM - the base station subsystem, network switching subsystem, and network management subsystem. It also discusses various technical aspects of GSM such as frequency division multiple access, time division multiple access, logical and physical channels, and call procedures.
Marketing implications of call drops for the patronage of gsm services in nig...Alexander Decker
This study examined the marketing implications of call drops for GSM services in Nigeria. A survey was conducted with 384 respondents from MTN, GLO, and Airtel networks in Imo and Abia States. The study found that call drops negatively impact customer loyalty, satisfaction, and patronage of GSM services. Factors like network quality, pricing, coverage, and call completion rates were found to influence customer choice of networks. Customers reported feeling dissatisfied when calls repeatedly dropped. The researchers recommended that the government and regulators more closely monitor operators' quality of service and pricing, and that network infrastructure be expanded to reduce call dropping, especially in rural areas.
Site specific assessment of node b using key service quality indicators over ...Alexander Decker
This document summarizes a study that assessed the quality of service of three Node B base stations (BEN 035, BEN026, and BEN 098) on a 3G/UMTS network in Benin City, Nigeria through outdoor drive-test measurements. Key quality indicators such as received signal code power (RSCP), energy per chip to total received power ratio (Ec/Io), and received signal strength indicator (RSSI) were measured along drive routes near each base station. The results found that BEN 035's Ec/Io range indicates it can support more subscribers, but tuning may be needed to reduce interference. QoS was very poor near BEN026, likely causing data access issues for users
SAMENA Response to Iraq CMC fixed wireless consultationroberto ercole
The document summarizes SAMENA's response to Iraq's Communications & Media Commission regarding proposed fixed wireless broadband licensing and spectrum allocation. Key points:
1. SAMENA believes licenses should allow both fixed and mobile broadband to promote broader access and a viable business case. Restricting licenses to just fixed use may undermine commercial deployment.
2. There may be cross-border interference issues, particularly with neighboring countries using all TDD networks in the 2.6GHz band. Band plans should be harmonized as much as possible to minimize interference.
3. The proposed amount of spectrum for fixed wireless may exceed market needs. A combined mobile/fixed approach could better support broadband access through economies of scale for operators.
GSM QUALITY OF SERVICE PERFORMANCE IN ABUJA, NIGERIAIJCSEA Journal
There has been tremendous growth in Global System for Mobile (GSM) services in Nigeria in the last two decade. The rapid development of GSM telecommunication industries have given rise to need for how the
GSM services are delivered to customers efficiently. This paper is on GSM quality of service (QoS) performance in, Abuja Nigeria. The study investigates network transmission impairment and offers some useful remedies. The method involved use of Sony Ericson W-995 phone to gather data on physical network impairments in selected densely populated areas of Abuja. The data obtained were from four major GSM
service providers MTN, Etisalat, Glo and Airtel. Assessment in terms of Key Performance Indicator (KPI) using Transmission Environment Monitory System (TEMS) Discovery professional software carried out on the networks under test. The results obtained from the analysis indicated that QoS performance of Airtel is slightly better than the other three GSM services providers tested within Nyanyan, Gwagwalada, and Wuse
areas in Abuja.
3G, or third generation mobile telecommunications, supports information transfer rates of at least 200 Kbit/s and provides higher speeds than previous 2G technologies. The two main 3G standards are UMTS, used primarily in Europe and standardized by 3GPP, and CDMA2000, used in North America and South Korea. 3G enabled rapid growth in data traffic such as text and web access through mobile phones, with projections of 50% of total mobile traffic consisting of data within 5 years of its introduction. It also facilitated increased mobile internet and device penetration.
The quality of service of the deployed LTE technology by mobile network opera...IJECEIAES
In this study, the real-world performance analysis of four Nigerian mobile network operators (MNOs), namely MTN, GLO, Airtel, and 9Mobile longterm evolution (LTE) cellular network, were analyzed and compared. The Nigerian MNOs utilize 5 MHz, 10 MH, and 20 MHz channel bandwidths based on third-generation partnership project’s (3 GPPs) recommendation. The presented analysis shows the uplink (UL), and downlink (DL) throughputs gaps in mobility condition as well as other LTE’s system quality of service (QoS) key performance indicators (KPI’s) of: Connection drop rate, connection failure rate, peak physical downlink throughput, minimum radio link control (RLC) downlink throughput threshold and latency are not strictly followed. The reason may be due to a lack of regulatory oversight enforcement. The comparative studies showed that MTN provides the best QoS. The introduction of novel LTE QoS metrics herein referred to as national independent wireless broadband quality reporting (NIWBQR) is the significant contribution of this study. The goal of this study is to show the quality of the network as it affects the user's experience. Important observation showed that all the MNOs are not adhering to the 3 GPPs specified user plane latency of 30 ms and control plane latency of 100 ms, respectively, which makes video streaming and low latency communication a near-impossible task.
The document is a training report submitted by Atul Sharma summarizing his internship at Idea Cellular pvt ltd. It provides an overview of GSM technology including its history and advantages. It describes the three subsystems of GSM - the base station subsystem, network switching subsystem, and network management subsystem. It also discusses various technical aspects of GSM such as frequency division multiple access, time division multiple access, logical and physical channels, and call procedures.
The telecom network in India is the fifth largest in the world and meets global standards. Currently, the Indian telecom industry contributes nearly 1% to India's GDP. The document provides a history of telecom in India beginning in 1851 and outlines key milestones such as the introduction of private sector involvement in the 1980s. It discusses government policies like the National Telecom Policy of 1999 which aimed to improve connectivity and quality of services. The rapid growth of the telecom sector post liberalization in 1991 is also summarized.
Introduction to Telecom Business & Management (ETE 521 L2)Nazirul Islam Zico
The document provides an overview of the telecommunication sector in Bangladesh, including its history, structure, key players and recent developments. It discusses the evolution of the sector from state-run monopolies to increased privatization and competition. Several charts and figures are presented analyzing trends in mobile and fixed-line subscriber growth, revenue, market share and ARPU among the major operators. The document aims to give context to the management of telecom businesses and the challenges in Bangladesh.
Investigating into the options available for rolling out (2)Abnor
This document discusses investigating options for rolling out 3G on Vodafone Ghana's network. It provides background on the evolution of mobile networks from 1G to 2G to 3G. It outlines objectives to explore Vodafone Ghana's existing infrastructure, requirements for introducing new 3G infrastructure, and options for implementing 3G in a cost-effective manner. Research methods include speaking to Vodafone Ghana, other network operators, technology providers, and customers to identify challenges with the current 2.5G network and recommend the best approach for upgrading to 3G.
Industrial training report on GSM Techology at BSNLAnshul Joshi
This document is an industrial report submitted by Anshul Joshi towards the partial fulfillment of requirements for a Bachelor of Technology degree in Electronics and Communication Engineering. It provides an acknowledgment, declaration, table of contents, and begins discussing the introduction and basic concepts of GSM technology, including definitions, the evolution of mobile telephone systems, and specifications of GSM. It also provides figures and discusses growth in cellular subscribers worldwide.
DIGITALLY CONNECTING RURAL INDIA BY 2018Kumar Ranjan
People in rural India has to first feel, learn benefits of Internet and start consuming Internet driven E-services. Government need to get all of its department ready to deliver various E-Governance and get eco-system ready & contents developed for various E-Services.
The document discusses key technology enablers for 5G networks, including 5G radio, ultra dense heterogeneous networks, mobile edge computing, network function virtualization, software defined networking, network slicing, and internet of things. The objectives of 5G include supporting peak data rates of 10Gbps, guaranteed rates of 50Mbps, latency of 1ms for radio access and 5ms end-to-end, high mobility up to 500km/hr, location accuracy of less than a meter, and connectivity for over 1 million devices per square kilometer. 5G aims to enable a wide range of new applications through these advanced capabilities.
Interesting Whitepaper from #HCLTECH, though a bit old (2016) but good for beginners on 5G and introductory know-how about 5G start with IMT2020. Informative insights.
This document discusses femtocells, which are small cellular base stations installed in homes to improve indoor mobile phone reception. It summarizes that femtocells connect directly to the cellular network instead of relying on outdoor macrocell towers, enhancing call quality when indoors. The document also examines femtocell integration into 3G network architectures and interference issues that may arise between femtocells and macrocells operating in limited licensed spectrum bands.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Year 2016 will see 3G subscription surpassing 2G subscription and will be more than 220million.
Countrywide launch by 3G/4G/LTE Services by Indian Telecom Operators will take Broadband Subscriber base to 600million by 2020. Further Digital India Initiative by Government of India to Rural India will take Broadband Subscriber to 1 Billion by 2023.
Mobile broadband is becoming a reality, as the Internet generation grows accustomed to having broadband access wherever they go, Out of 5.8 billion people who will have broadband by 2017. It should surprise no one that the Smartphone revolution is fueling this growth, and by 2017, half of all mobile devices in the world will be smart phones. The key to keeping users happy is network performance and good value for the money. From the looks of it, we are on track to seeing continued network performance improvements and increasingly easier access to smart phones as developing markets hop on the bandwagon.
Telecommunications network operators around the world are increasingly looking to decommission older legacy networks as new technologies are deployed and network traffic grows rapidly. The document discusses the key findings of a global study on network decommissioning conducted by PwC in 2012. Key points include:
- Nearly 90% of wireline and over 60% of wireless operators surveyed planned to decommission legacy networks in the next 5 years.
- Primary drivers for decommissioning are reducing operating costs and improving customer experience.
- Over 90% of wireless network decommissioning will involve 2G technologies, while wireline decommissioning will focus on copper networks.
- Approaches to decommissioning include turning networks off, physical removal of
What is GSM?
Global System for Mobile Communications, or GSM for short, is a digital mobile communications standard developed by the European Telecommunications Standards Organization ETSI. It uses time division multiple access technologies for its air interface. Since its commercial introduction in the mid-1990s, it has been adopted by more than 100 countries worldwide.
GSM is an open standard currently being developed by 3GPP. 2015, many GSM network are used by operators worldwide.
GSM belongs to the 2nd generation (2G) cellular mobile communication technology. Analog cellular technology is known as Generation 1 mobile technology, and broadband CDMA technology is known as Generation 3 mobile technology, or 3G.
GSM is a digital cell phone network standard developed in Europe to allow users to use one cell phone network standard for all parts of the world so that users can travel around the world with one cell phone.
IRJET - Comparative Study of Rural Macrocell (RMA) and Urban Macrocell (U...IRJET Journal
This document provides a comparative study of rural macrocell (RMa) and urban macrocell (UMa) propagations for millimeter wave 5G cellular networks. It analyzes the performance of RMa and UMa based on their power delay profiles (PDP) for specific frequencies between 16-82 GHz. The study is done for line of sight communication. Simulations are performed using the NYUSIM software which uses MATLAB. Parameters like pathloss, pathloss exponent, and received power are used to measure performance. The results show characteristic curves for each frequency band in both RMa and UMa propagations. The outcomes are compared to determine the most effective frequency bands for 5G cellular communication based on propagation type.
hi guys!! check out the details about the tele communication and community services in urban infrastructure. If u want best architecture and interior services, click on https://jakkan.com/ and contact them. They give best services.
The document discusses the third generation (3G) of mobile telecommunications technology. 3G networks were introduced in 1998 and provide higher data rates and non-backward compatible transmission compared to previous generations. 3G offers advantages like more bandwidth, security, reliability and rich multimedia services, but also has disadvantages such as expensive licensing fees, infrastructure costs, and large phone sizes.
GSM QUALITY OF SERVICE PERFORMANCE IN ABUJA, NIGERIAIJCSEA Journal
There has been tremendous growth in Global System for Mobile (GSM) services in Nigeria in the last two decade. The rapid development of GSM telecommunication industries have given rise to need for how the GSM services are delivered to customers efficiently. This paper is on GSM quality of service (QoS) performance in, Abuja Nigeria. The study investigates network transmission impairment and offers some useful remedies. The method involved use of Sony Ericson W-995 phone to gather data on physical network impairments in selected densely populated areas of Abuja. The data obtained were from four major GSM service providers MTN, Etisalat, Glo and Airtel. Assessment in terms of Key Performance Indicator (KPI) using Transmission Environment Monitory System (TEMS) Discovery professional software carried out on the networks under test. The results obtained from the analysis indicated that QoS performance of Airtel is slightly better than the other three GSM services providers tested within Nyanyan, Gwagwalada, and Wuse areas in Abuja
STATISTICAL ANALYSIS OF RECEIVED POWER IN AN ANTENNA DOWN- TILT ON CELLULAR N...IRJET Journal
This document discusses statistical analysis of received power in antenna down-tilt for cellular networks. It begins by providing background on 2G, 3G, 4G, and 5G mobile networks and their components. It then discusses radio propagation models and how antenna down-tilt works to improve network performance by optimizing the signal level within a cell and minimizing it elsewhere. The effect of down-tilt angle on received power and signal-to-noise/interference ratios is examined. Formulas for calculating the optimal down-tilt angle based on factors like base station height, cell radius, and antenna beamwidth are also provided. Data collected from test cellular sites is analyzed before and after antenna parameter adjustments to demonstrate the impact of down-tilt
Refarming frequencies in rural areas A Regulatory Perspective - Enrico Caland...ACORN-REDECOM
This paper seeks to assess radio-spectrum refarming in selected African countries. It provides an overview of the debate
around spectrum refarming and it presents case studies that offer insights into the African context. This discussion identifies
regulatory constrains hindering an optimal usage of premium frequencies and provides policy and regulatory
recommendations on how to facilitate spectrum refarming.
Findings show that the analysed African regulatory environments have implemented a technology-neutral licensing regime to
enhance competition. Although this regulatory intervention opened up the market by enhancing market opportunities and
granting additional licenses, some of the new licensees cannot begin operations because of an artificially created scarcity of
spectrum. Further, new licensing frameworks have created a competitive advantage for those operators already holding
premium frequencies, as they can refarm assigned spectrum bands positioning themselves as both voice and data service
providers.
In addition, due to regulatory delays in liberalising and refarming frequencies suitable for wireless broadband roll-out such as
2.6GHz and 3.5GHz, incumbent operators are merging with smaller telcos, in order to access additional spectrum for the
provision of wireless broadband services. This is leading to a spectrum hoarding.
Evaluation of Percentage Capacity Loss on LTE Network Caused by Intermodulati...Onyebuchi nosiri
The document evaluates the capacity loss of an LTE network (VISAFONE) due to interference from neighboring networks. It finds that third-order intermodulation distortion (IMD3) between the downlink of an LTE network (INTERCELLULAR) and the uplink of a GSM network (ETISALAT) generates interfering frequencies within the victim receiver's passband. MATLAB simulations were run to evaluate capacity loss at the VISAFONE LTE receiver for distances from 500m to 3000m between the interfering networks. Results showed 80% capacity loss at 500m, decreasing to 5.97% at 3000m, demonstrating that closer distances lead to more severe interference and capacity degradation for the victim LTE network.
The telecom network in India is the fifth largest in the world and meets global standards. Currently, the Indian telecom industry contributes nearly 1% to India's GDP. The document provides a history of telecom in India beginning in 1851 and outlines key milestones such as the introduction of private sector involvement in the 1980s. It discusses government policies like the National Telecom Policy of 1999 which aimed to improve connectivity and quality of services. The rapid growth of the telecom sector post liberalization in 1991 is also summarized.
Introduction to Telecom Business & Management (ETE 521 L2)Nazirul Islam Zico
The document provides an overview of the telecommunication sector in Bangladesh, including its history, structure, key players and recent developments. It discusses the evolution of the sector from state-run monopolies to increased privatization and competition. Several charts and figures are presented analyzing trends in mobile and fixed-line subscriber growth, revenue, market share and ARPU among the major operators. The document aims to give context to the management of telecom businesses and the challenges in Bangladesh.
Investigating into the options available for rolling out (2)Abnor
This document discusses investigating options for rolling out 3G on Vodafone Ghana's network. It provides background on the evolution of mobile networks from 1G to 2G to 3G. It outlines objectives to explore Vodafone Ghana's existing infrastructure, requirements for introducing new 3G infrastructure, and options for implementing 3G in a cost-effective manner. Research methods include speaking to Vodafone Ghana, other network operators, technology providers, and customers to identify challenges with the current 2.5G network and recommend the best approach for upgrading to 3G.
Industrial training report on GSM Techology at BSNLAnshul Joshi
This document is an industrial report submitted by Anshul Joshi towards the partial fulfillment of requirements for a Bachelor of Technology degree in Electronics and Communication Engineering. It provides an acknowledgment, declaration, table of contents, and begins discussing the introduction and basic concepts of GSM technology, including definitions, the evolution of mobile telephone systems, and specifications of GSM. It also provides figures and discusses growth in cellular subscribers worldwide.
DIGITALLY CONNECTING RURAL INDIA BY 2018Kumar Ranjan
People in rural India has to first feel, learn benefits of Internet and start consuming Internet driven E-services. Government need to get all of its department ready to deliver various E-Governance and get eco-system ready & contents developed for various E-Services.
The document discusses key technology enablers for 5G networks, including 5G radio, ultra dense heterogeneous networks, mobile edge computing, network function virtualization, software defined networking, network slicing, and internet of things. The objectives of 5G include supporting peak data rates of 10Gbps, guaranteed rates of 50Mbps, latency of 1ms for radio access and 5ms end-to-end, high mobility up to 500km/hr, location accuracy of less than a meter, and connectivity for over 1 million devices per square kilometer. 5G aims to enable a wide range of new applications through these advanced capabilities.
Interesting Whitepaper from #HCLTECH, though a bit old (2016) but good for beginners on 5G and introductory know-how about 5G start with IMT2020. Informative insights.
This document discusses femtocells, which are small cellular base stations installed in homes to improve indoor mobile phone reception. It summarizes that femtocells connect directly to the cellular network instead of relying on outdoor macrocell towers, enhancing call quality when indoors. The document also examines femtocell integration into 3G network architectures and interference issues that may arise between femtocells and macrocells operating in limited licensed spectrum bands.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Year 2016 will see 3G subscription surpassing 2G subscription and will be more than 220million.
Countrywide launch by 3G/4G/LTE Services by Indian Telecom Operators will take Broadband Subscriber base to 600million by 2020. Further Digital India Initiative by Government of India to Rural India will take Broadband Subscriber to 1 Billion by 2023.
Mobile broadband is becoming a reality, as the Internet generation grows accustomed to having broadband access wherever they go, Out of 5.8 billion people who will have broadband by 2017. It should surprise no one that the Smartphone revolution is fueling this growth, and by 2017, half of all mobile devices in the world will be smart phones. The key to keeping users happy is network performance and good value for the money. From the looks of it, we are on track to seeing continued network performance improvements and increasingly easier access to smart phones as developing markets hop on the bandwagon.
Telecommunications network operators around the world are increasingly looking to decommission older legacy networks as new technologies are deployed and network traffic grows rapidly. The document discusses the key findings of a global study on network decommissioning conducted by PwC in 2012. Key points include:
- Nearly 90% of wireline and over 60% of wireless operators surveyed planned to decommission legacy networks in the next 5 years.
- Primary drivers for decommissioning are reducing operating costs and improving customer experience.
- Over 90% of wireless network decommissioning will involve 2G technologies, while wireline decommissioning will focus on copper networks.
- Approaches to decommissioning include turning networks off, physical removal of
What is GSM?
Global System for Mobile Communications, or GSM for short, is a digital mobile communications standard developed by the European Telecommunications Standards Organization ETSI. It uses time division multiple access technologies for its air interface. Since its commercial introduction in the mid-1990s, it has been adopted by more than 100 countries worldwide.
GSM is an open standard currently being developed by 3GPP. 2015, many GSM network are used by operators worldwide.
GSM belongs to the 2nd generation (2G) cellular mobile communication technology. Analog cellular technology is known as Generation 1 mobile technology, and broadband CDMA technology is known as Generation 3 mobile technology, or 3G.
GSM is a digital cell phone network standard developed in Europe to allow users to use one cell phone network standard for all parts of the world so that users can travel around the world with one cell phone.
IRJET - Comparative Study of Rural Macrocell (RMA) and Urban Macrocell (U...IRJET Journal
This document provides a comparative study of rural macrocell (RMa) and urban macrocell (UMa) propagations for millimeter wave 5G cellular networks. It analyzes the performance of RMa and UMa based on their power delay profiles (PDP) for specific frequencies between 16-82 GHz. The study is done for line of sight communication. Simulations are performed using the NYUSIM software which uses MATLAB. Parameters like pathloss, pathloss exponent, and received power are used to measure performance. The results show characteristic curves for each frequency band in both RMa and UMa propagations. The outcomes are compared to determine the most effective frequency bands for 5G cellular communication based on propagation type.
hi guys!! check out the details about the tele communication and community services in urban infrastructure. If u want best architecture and interior services, click on https://jakkan.com/ and contact them. They give best services.
The document discusses the third generation (3G) of mobile telecommunications technology. 3G networks were introduced in 1998 and provide higher data rates and non-backward compatible transmission compared to previous generations. 3G offers advantages like more bandwidth, security, reliability and rich multimedia services, but also has disadvantages such as expensive licensing fees, infrastructure costs, and large phone sizes.
Similar to Improving Quality of Service in GSM By Reducing Probability of Call Blocking Through Network Dimensioning Using Erlang B Model and Congestion Control Algorithm
GSM QUALITY OF SERVICE PERFORMANCE IN ABUJA, NIGERIAIJCSEA Journal
There has been tremendous growth in Global System for Mobile (GSM) services in Nigeria in the last two decade. The rapid development of GSM telecommunication industries have given rise to need for how the GSM services are delivered to customers efficiently. This paper is on GSM quality of service (QoS) performance in, Abuja Nigeria. The study investigates network transmission impairment and offers some useful remedies. The method involved use of Sony Ericson W-995 phone to gather data on physical network impairments in selected densely populated areas of Abuja. The data obtained were from four major GSM service providers MTN, Etisalat, Glo and Airtel. Assessment in terms of Key Performance Indicator (KPI) using Transmission Environment Monitory System (TEMS) Discovery professional software carried out on the networks under test. The results obtained from the analysis indicated that QoS performance of Airtel is slightly better than the other three GSM services providers tested within Nyanyan, Gwagwalada, and Wuse areas in Abuja
STATISTICAL ANALYSIS OF RECEIVED POWER IN AN ANTENNA DOWN- TILT ON CELLULAR N...IRJET Journal
This document discusses statistical analysis of received power in antenna down-tilt for cellular networks. It begins by providing background on 2G, 3G, 4G, and 5G mobile networks and their components. It then discusses radio propagation models and how antenna down-tilt works to improve network performance by optimizing the signal level within a cell and minimizing it elsewhere. The effect of down-tilt angle on received power and signal-to-noise/interference ratios is examined. Formulas for calculating the optimal down-tilt angle based on factors like base station height, cell radius, and antenna beamwidth are also provided. Data collected from test cellular sites is analyzed before and after antenna parameter adjustments to demonstrate the impact of down-tilt
Refarming frequencies in rural areas A Regulatory Perspective - Enrico Caland...ACORN-REDECOM
This paper seeks to assess radio-spectrum refarming in selected African countries. It provides an overview of the debate
around spectrum refarming and it presents case studies that offer insights into the African context. This discussion identifies
regulatory constrains hindering an optimal usage of premium frequencies and provides policy and regulatory
recommendations on how to facilitate spectrum refarming.
Findings show that the analysed African regulatory environments have implemented a technology-neutral licensing regime to
enhance competition. Although this regulatory intervention opened up the market by enhancing market opportunities and
granting additional licenses, some of the new licensees cannot begin operations because of an artificially created scarcity of
spectrum. Further, new licensing frameworks have created a competitive advantage for those operators already holding
premium frequencies, as they can refarm assigned spectrum bands positioning themselves as both voice and data service
providers.
In addition, due to regulatory delays in liberalising and refarming frequencies suitable for wireless broadband roll-out such as
2.6GHz and 3.5GHz, incumbent operators are merging with smaller telcos, in order to access additional spectrum for the
provision of wireless broadband services. This is leading to a spectrum hoarding.
Evaluation of Percentage Capacity Loss on LTE Network Caused by Intermodulati...Onyebuchi nosiri
The document evaluates the capacity loss of an LTE network (VISAFONE) due to interference from neighboring networks. It finds that third-order intermodulation distortion (IMD3) between the downlink of an LTE network (INTERCELLULAR) and the uplink of a GSM network (ETISALAT) generates interfering frequencies within the victim receiver's passband. MATLAB simulations were run to evaluate capacity loss at the VISAFONE LTE receiver for distances from 500m to 3000m between the interfering networks. Results showed 80% capacity loss at 500m, decreasing to 5.97% at 3000m, demonstrating that closer distances lead to more severe interference and capacity degradation for the victim LTE network.
Evaluation of Percentage Capacity Loss on LTE Network Caused by Intermodulati...Onyebuchi nosiri
Abstract- The paper evaluates the effects of third order Intermodulation Distortion (IMD3) on the Long Term Evolution (LTE) receiver due to coexistence between LTE and GSM networks. Amongst the various existing IMD orders which include first order, second order, third order, fifth order and seventh order. Third order is known to have the greatest distortion effects on a receiver due to its strength and its proximity to the frequency band of interest. It occurs as a result of the non-linear behavior of components or circuit at both the transmitter and receiver ends of wireless communication networks. IMD has potential negative effects on a victim receiver which majorly leads to increase in noise floor level and system capacity degradation. Deterministic approach was implemented in the work assuming worst case scenario. MATLAB software simulation was deployed to evaluate the capacity loss at the receiver end relative to a range of distances apart. Results obtained showed severe uplink capacity degradation when VISAFONE LTE network was interfered by INTERCELLULAR LTE downlink and ETISALAT GSM uplink. Various distances ranging from 500m to 3000m were varied between the ETISALAT GSM network and the VISAFONE LTE network. The results obtained showed that at 500 meters, the percentage capacity degradation was as high as 80. The least percentage capacity loss was obtained as 5.97 at 3000 meters.
5G Technology: An Assessment of the Opportunities and Challenges in an Emergi...josephjonse
No country wants to be left behind in the tech war as there may be far-reaching consequences in military, health, and well-being, industrial applications, technology, banking, financial services, urbanization, and other facets of private and national life. For an emergent country like Nigeria, the cost of being left behind is enormous and may mean the continuous peril of underdevelopment wrought by over-dependence on other nations for essential services. This paper provides perspectives on sectors where the deployment of the 5G telecommunication network could be a swift driver of an emergent Nigeria. It also highlights the particular challenges facing the deployment of the 5G technology in Nigeria. The study adopted the use of secondary sources to obtain relevant preexisting data to facilitate the research objectives. Restrictions in movement necessitated this approach to curtail the spread of the Coronavirus. The research findings revealed the enormous multi-sectorial benefits of deploying the 5G technology in an emergent Nigeria and the inherent challenges. It is envisaged that the ideas highlighted in the study findings would provide useful guidance for policy directors in the quest for a better emergent Nigeria.
5G Technology: An Assessment of the Opportunities and Challenges in an Emergi...josephjonse
No country wants to be left behind in the tech war as there may be far-reaching consequences in military, health, and well-being, industrial applications, technology, banking, financial services, urbanization, and other facets of private and national life. For an emergent country like Nigeria, the cost of being left behind is enormous and may mean the continuous peril of underdevelopment wrought by over-dependence on other nations for essential services. This paper provides perspectives on sectors where the deployment of the 5G telecommunication network could be a swift driver of an emergent Nigeria. It also highlights the particular challenges facing the deployment of the 5G technology in Nigeria. The study adopted the use of secondary sources to obtain relevant preexisting data to facilitate the research objectives. Restrictions in movement necessitated this approach to curtail the spread of the Coronavirus. The research findings revealed the enormous multi-sectorial benefits of deploying the 5G technology in an emergent Nigeria and the inherent challenges. It is envisaged that the ideas highlighted in the study findings would provide useful guidance for policy directors in the quest for a better emergent Nigeria.
This document summarizes previous literature on traffic analysis and congestion modeling in mobile networks. It reviews works that have evaluated network performance at different elements like the BTS, BSC and MSC. However, none addressed congestion at all three basic elements (BTS, BSC, MSC) to characterize end-to-end connections, or used busy hour traffic data to adequately dimension network elements. The document also identifies gaps in the existing research, such as not establishing the statistical causes of congestion or using sufficient data. It proposes to analyze traffic at the access and core networks using live network data over two years to help dimension elements and identify congestion causes to develop an accurate congestion prediction model.
Litrature Survey of Traffic Analysis and Congestion Modeling In Mobile Network iosrjce
Network congestion is one of the major problems of GSM service providers as the number of
subscribers increase and new services are introduced. All the proposed techniques in literatures for controlling
congestion are centered on two principles which are either to reject excessive traffic to prevent over-utilization
of network resources or diverting excess load if overload occurs. These techniques do not specify how network
resource can be provided to absorb rejected or diverted traffic so that revenue will not be lost during congestion
and hence, they do not really address congestion during busy hour. Real-time traffic analysis is required to
understand user traffic demand pattern on network resources for proper prediction of network congestion so
that resources can be provided to take care of rejected or diverted traffic. However, available literature survey
on mobile network congestion modeling showed that none of the existing literature: address congestion at the
three basic elements of GSM network to characterize end-to-end connection; use busy hour traffic data to
adequately dimension GSM network elements so that the network can cope with load B. Therefore, effective
congestion control mechanism that can take these research gaps into consideration for proper forecasting and
efficient dimension of the network resources to address busy hour congestion must be developed. This paper is a
preliminary report on development of such accurate congestion prediction model through an ongoing research
work using real live network data from one of the Service provider’s networks in Abuja, Nigeria as a case study
A STUDY ON THE APPLICATIONS OF 2G AND 3G SERVICES OF MOBILE AMONG STUDENTS ...Rana Bhowal
This document is a project report submitted by Rana Bhowal to fulfill the requirements of a Bachelor's degree in Commerce from Dibrugarh University. The report studies the applications of 2G and 3G mobile services among students and their implications. It provides an introduction to 2G and 3G technologies, standards, capacities, benefits, advantages and disadvantages. It outlines the objectives and methodology of the study. The report analyzes survey data collected from students on their knowledge and usage of 2G and 3G services. It presents major findings and implications, and provides conclusions and suggestions.
This document discusses 5G technology and Non-Orthogonal Multiple Access (NOMA). It provides an overview of 5G, describing how 5G will enable higher data rates and bandwidth. NOMA is introduced as an emerging technology for 5G that uses power multiplexing to serve multiple users on the same time and frequency resources, providing higher spectral efficiency and lower latency compared to previous orthogonal multiple access techniques. The advantages of NOMA include higher throughput, massive connectivity, lower latency and improved quality of service. Potential applications discussed include supporting increased device connectivity for areas like the Internet of Things.
This document summarizes a project that mapped telecommunications coverage at public health facilities in Kano State, Nigeria to evaluate network performance for mobile health services. The project used a phone survey and geographic information systems (GIS) mapping using an app called Crisis Signal to collect signal strength data from 4 major networks (MTN, Etisalat, Glo, Airtel) at 180 health facilities. The data analysis found that MTN had the best overall signal strength and reliability for voice and data, making it the recommended top choice for mobile health services, followed by Airtel, Etisalat, and Glo. Maps were created in CartoDB to visualize the network coverage heat maps. The project demonstrated how GIS mapping
NTT DoCoMo and the Future Implications of HighLuke Markey
NTT DoCoMo has pioneered 4G mobile networks through its domestic ecosystem in Japan. The document discusses the evolution of mobile networks from 1G to 4G, highlighting NTT DoCoMo's innovations. Key aspects of NTT DoCoMo's 4G network include using existing frequency carrier technology from older standards to increase bandwidth, and adopting the LTE-Advanced standard to build upon existing 3G infrastructure through gradual upgrades. This allows for a simpler transition to fully realizing the goals of 4G networks for high-speed mobile broadband.
MOBILITY AND ROUTING BASED CHANNEL ESTIMATION FOR HYBRID MILLIMETER-WAVE MIMO...IJCNCJournal
Recently, technological developments have enhanced, the use of Millimeter-wave (mm-Wave) Multiple Input Multiple Output (MIMO) system in various communication applications and wireless sensor networks as channel estimation efficiency can be immensely improved with the help of this technological developments in Millimeter-wave MIMO system and wireless sensor network as well. Moreover, they can improve quality of communication services to a great extent. However, cell interference in Millimeter-wave (mm-Wave) MIMO system can produce a massive impact on spectral efficiency. Therefore, a Routing Enabled Channel Estimation (RECE) technique is presented in this article to minimize interference between cells. The proposed Channel Estimation technique improves channel capacity as well as spectral efficiency. Moreover, Normalized Mean Square Error (NMSE) is minimized heavily using proposed RECE technique. Here, main aim of this article is to reduce cell interference and channel estimation inside a cell by using route selection, beam selection, and spatial frequency estimation. Here, different scenarios and parameters are considered to evaluate performance efficiency of proposed RECE technique in terms of spectral efficiency, NMSE and SNR and compared against varied traditional channel estimation techniques. Moreover, it is clearly evident from performance results that the proposed channel estimation technique performs better than the other two methods.
Mobility and Routing based Channel Estimation for Hybrid Millimeter-Wave MIMO...IJCNCJournal
This document summarizes a research paper that proposes a Routing Enabled Channel Estimation (RECE) technique for hybrid millimeter-wave MIMO wireless sensor networks. The technique aims to reduce interference between cells to improve spectral efficiency and capacity. It uses route selection, beam selection, and spatial frequency estimation to minimize interference within a cell. The performance of the proposed RECE technique is evaluated based on metrics like spectral efficiency, normalized mean square error, and SNR and is shown to outperform other traditional channel estimation methods. The mathematical modeling of the proposed technique is also presented.
The benefit of technology neutral spectrum licences 25 sep 2020Coleago Consulting
Technology neutral spectrum licensing allows mobile operators to refarm spectrum from older technologies like 2G and 3G to newer technologies like 4G and 5G based on market demand. This maximizes spectral efficiency and the economic benefits of new technologies by providing higher data speeds and lower prices to users. However, some countries have delayed adopting technology neutral licensing, depriving users of these benefits and hindering the growth of their digital economies. Making existing spectrum licenses technology neutral can help accelerate the rollout of 4G and 5G networks without delay.
This document summarizes an analysis of the opportunity cost of spectrum for mobile communication in Bangladesh. It presents estimates of the opportunity cost of 2G, 3G, and 4G spectrum using engineering valuation and production function methods. The engineering valuation method estimates costs based on the number of base transceiver stations required for network coverage with and without additional spectrum. The production function method estimates costs based on the relationship between spectrum assigned and mobile subscriptions. The analysis finds that spectrum prices in Bangladesh have exceeded opportunity cost estimates, and that regulators must balance spectral efficiency and capacity needs when setting reserve prices, especially for new technologies like 5G.
5G is happening now with progress being made on technologies and policies. Key 5G capabilities defined by ITU include increased data rates, reduced latency, and higher connection densities. 5G will support new usage scenarios for enhanced mobile broadband, massive machine type communications, and ultra-reliable low latency communications. The EU has taken steps toward 5G readiness but there are gaps between Western and Eastern Europe. Spectrum policy will be important to support 5G networks and making services affordable. Most EU countries plan to launch 5G in 2020 to meet digital agenda targets.
5G spectrum and beyond will transform the telecommunications sector through disruptive technologies driven by market demands. 5G will provide integrated broadband services for the future through innovative shifts in infrastructure to meet international 5G standards. Governments and industry are working to define 5G's technical characteristics and address spectrum needs and regulatory challenges to realize 5G's benefits across sectors. Namibia aims to meet 5G standards through regional cooperation and technologies to resolve increasing mobile demands.
Similar to Improving Quality of Service in GSM By Reducing Probability of Call Blocking Through Network Dimensioning Using Erlang B Model and Congestion Control Algorithm (20)
Efforts made in many countries to stop the COVID-19 pandemic include vaccinations. However,
public skepticism about vaccines is a pressing issue for health authorities. With the COVID-19 vaccine
available,
SARS-CoV-2, as the causative agent of COVID-19, has spread throughout the world after becoming
a pandemic in March 2020. In the midst of the ongoing COVID-19 pandemic, we are also faced with another
serious health problem
This paper discusses the construction and implementation of a system for the measurement of
electrical power parameters; amperage and voltage of the hybrid system photovoltaic solar-wind, to evaluate
the system parameters and performance. The basis of the development of the measuring apparatus is the use of
an Arduino Mega 2560 to provide the interface between the electrical circuits of the sensors and the dynamics
of the voltage-amperage as well as collect data in an analog format as well as development of functional
dependence relationships. The collected data is converted into digital format and stored it in an Excel format
through the "PLX-DAQ Spreadsheet" that connects the Arduino and the PC for display and analysis of the
system parameters. The proposed technique for power measurements of AC and DC proved to be reliable and
can predict the power amperage and voltage within relative error of 1.63 % for AC and 4.16% for DC,
respectively.
The optimum speed required for mass-size reduction of shells to produce most sizes that are small
comparable with kernel sizes; coupled with retention of kernel wholeness in cracked palm nut mixture under
repeated impact was investigated. This is to enhance whole kernel separation by dry method, reduce maintenance
and production cost of palm kernel oil (PK0); and lower the risk of oil rancidity associated with split kernel
production and wet method of separation. A static nut cracker and centrifugal nut cracker were used in this study as
Test Rigs while sieves were used to grade cracked shells and whole kernels. The data generated were evaluated. A
model was developed for energy via speed required to retain kernels wholeness following repeated impact in the
crackers. Technical analysis revealed that the maximum allowable speed to retain kernel wholeness is 27.93 m/s;
the minimum allowable average speed to fragment cracked shells is 24.95 m/s. Further analysis showed that the
optimum speed and energy required for cracked nut mixture under repeated impact to have kernel wholeness
retention and production of small sizes of cracked shells relative to kernel sizes are 25.71 m/s and 0.4 J,
respectively.
This review was written to provide a comprehensive summary of the suggested etiologies of Chronic Kidney
Disease of Unknown Etiology (CKDu) in Sri Lanka. In this review, Chronic Kidney Disease (CKD) is explained
in detail and its known etiologies are discussed. CKDu is defined and its epidemiology is discussed, with the
compilation of statistic from over 15 research papers through the years 2000 to present.
This work contributes to the monitoring of water pollution of some selected Dams in Katsina
State, North western Nigeria by assessing the degree of heavy metal pollution in the Dams sediment samples.
The study was conducted in the year 2017 within some selected Dams in the State (Ajiwa, Zobe,
Sabke/Dannakola) that are beehives of fishing and Agricultural activities in Katsina State. Analysis for the
concentration of these heavy metals; Cr, Cd, Fe, Ni, Mn, Pb and Zn was conducted by the use of AAS (by
Atomic Absorption Spectrophotometry) method. Several indices were used to assess the metal contamination
levels in the sediment samples, namely; Geo-accumulation Index (Igeo), Enrichment Factor (EF),
Contamination Factor (CF), Degree of Contamination (Cd), Pollution Load Index (PLI) and Potential
Ecological Risk Index (PERI). The result of this study has shown that generally among the heavy metals
evaluated, the highest concentration was observed for Fe (range: 2.6718-4.2830 ppm), followed by Zn (range:
0.4265-0.7376 ppm), Cr (range: 0.1106-0.1836 ppm), Cd (range: 0.1333-0.1273 ppm) and Mn (range: 0.1136-
0.1271 ppm). While Pb has the lowest concentration (range: 0.0472-0.0598 ppm). For all the site sampled the
heavy metal Ni was below detection level (BDL). From the results of heavy metals I-geo values, according to
Muller’s classification, all the sediment samples from the selected dams were unpolluted (class 0). The result for
the enrichment factor has shown that for all the selected dam sediment samples the heavy metals show
deficiency to minimal enrichment. Also based on the contamination factors for all sediment samples the heavy
metal Cd has a CF values range of 0.5430-0.6665 (~1), indicating that the sediment samples are moderately
contaminated with Cd. In contrast, the rest of the heavy metals exhibit low contamination in general. The value
of PLI ranges from 0.2408 to 0.4935, indicating unpolluted to moderate pollution. The Eri values for all
samples are all < 40, presenting low ecological risk. The results suggest that the sediment samples from the
selected dams in Katsina state has low contamination by the heavy metals evaluated.
Using QR Decomposition to calculate the sum of squares of a model has a limitation that the number of rows,
which is also the number of observations or responses, has to be greater than the total number of parameters used in the
model. The main goal in the experimental design model, as a part of the Linear Model, is to analyze the estimable function
of the parameters used in the model. In order not to deal with generalized invers, partitioned design matrix may be used
instead. This partitioned design matrix method may be used to calculate the sum of squares of the models whenever the total
number of parameters is greater than the number of observations. It can also be used to find the degrees of freedom of each
source of variation components. This method is discussed in a Balanced Nested-Factorial Experimental Design.
Introduction:It has been proven twice that the Hambantota District has the highest life expectancy in male
population. This study focused to find and identify reasons for Hambantota District people to have high life
expectancy at birth.
Methodology: Research was carried out in both qualitative and quantitative phases in five MOH (Medical
Health Officer) divisions in HambantotaDistrict. Study focused on 3 age categories, 55-65 Years, 66-75 Years,
and above 76 Years. Main objectives and key information areas are Life Style and Social Behaviors, Food
Consumption and Diet, Familial Trait and Physical and Mental Health.
Findings: Majority of the male population have educated up to grade 5and most are engaged in the agriculture
while others engaged in fishery and self-employment etc. Almost everyone reachestheir workplaces by foot or by
bicycle. Many of them work less than six hours. They spend their free time with their family members and watch
TV. Most of them do not consume alcohol and smoke. Almost everyone take part in social activities. Majority eat
red rice for all three meals. Almost everyone eats fish every day. They have a high salt intake. Their parents and
ancestors have also have had a high life expectancy. Only a minority suffer from chronic illnesses. They all have
a good physical and mental health condition. They spend happy and relaxed lifestyle.
Conclusion: Healthy diet, low alcohols consumption and smoking, high iodine intake, physical activeness and
their social wellbeing effect for high life expectancy within the male population of selected five MOH divisions
in Hambantota District. They have a free and happy life. Genetics of these people also may contribute for high
life expectancy. Abundance of neem trees in this area also may effect on their high life expectancy.
A clay deposit in Chavakali of western Kenya was evaluated for its potential as refractory raw
material. The collected clay sample was crushed, sieved and the chemical composition determined in
percentage weight (wt %) of (SiO2, Al2O3, Fe2O3, etc) using Atomic Absorption Spectrophotometer (AAS). The
samples were moulded into rectangular shaped bricks of 40mm height, 40mm width and 80mm length, allowed
to dry and later fired up to a temperature of 10000C. Refractory properties like Compressive strength,
Hardness, Linear shrinkage on firing, Apparent porosity and Density were determined using standard
techniques. The result of chemical analysis indicated that the clay was composed of Silica (SiO2), 67.3%;
Alumina (Al2O3), 16.67%; Iron Oxide (Fe2O3), 3.87%; Calcium Oxide (CaO), 0.37%; Potassium Oxide (K2O),
2.30%; Sodium Oxide (Na2O), 1.39%; and other traces. The physical and mechanical tests show that the clay
has Cold Crushing Strength of 10.36MPa, Hardness of 40.080 GPa, Linear shrinkage of 6.17%, Apparent
Porosity of 32.71% and Bulk Density of 2.77g/cm3
. Chavakali clay can make better local refractory
Nihon University challenged world record of the human-powered aircraft flight based on the
regulation of Fédération Aérionautique Internationale in Kasumigaura Lake, Japan, 2014. The wing fell off in
midair immediately after take-off, the pilot landed to the lake for safety. So, the challenge failed. It guessed the
operational errors were correlated with the wing falling in midair, which had not happened in our experience.
The flight recording camera and the salvaged airplane were investigated. The fault tree analysis was conducted
for cause investigation. The wing falling was the result as the chain destruction starting from the coupling parts
being damaged in take-off. The defective take-off was caused by composite factors on only operational errors.
The risk that the ultralight airplane might disintegrate in midair by only operational error became apparent.
Due to the large-scale exploitation of mineral resources and the unreasonable human activities, the
geological disasters in Jiaozuo City have become increasingly prominent and the degree of harm increased. This
leds to a tremendous threat to human life and property safety. Jiaozuo City, the main types of geological
disasters, landslides, ground subsidence, debris flow and ground fissures. It has great significance to the
development of the city and the protection of people's life and property to explore the hidden dangers of
geological disasters and actively take preventive and control measures. The establishment of geological
hazard group measurement system of prevention and control to achieve the timely detection of geological
disasters, rapid early warning and effective avoidance.
Dangerous gas explosion accidents result in considerable amount of casualties and property damage.
Hence, an investigation on the generation of poisonous gases in gas explosions exerts important implications
for accident prevention and control and in the decision-making processes of fire rescue. Therefore, a gas
explosion piping test system is established in this paper. Experimental research on gas explosion is conducted by
selecting methane/air premixed gases with concentrations of 7%, 9%, 11%, 13%, and 15% in the gas explosive
range. This research aims to reveal the regularity of CO generation after gas explosion in pipelines.
Experimental results showed that when the gas concentration is small (< 9%), 1500–3000 ppm CO will be
produced. When the gas concentration is large (> 9%), the CO amount will reach 3000–40000 ppm. The
variation trend in CO concentration and the quantity of explosive gas are also obtained.
1) The document examines the influence of entry speed on water entry phenomena through experimental visualization of the flow field above the water surface. Entry speeds ranged from 0.2 to 1.5 km/s.
2) It was found that above a critical entry speed, the vertical velocity of the water splash tip was linearly proportional to its vertical location, and the ratio of initial splash velocity to entry speed was constant.
3) A shock wave was driven above the water surface even for subsonic entry speeds, and its propagation followed a scaling law for explosive shock waves where projectile kinetic energy replaced explosive energy.
Pingdingshan Coal Mine district is one of the six mining areas of Henan Province, which is a
large coal base in China. After 60 years of exploitation, it has brought great benefits, at the same time,
serious geological disasters have been occurred. It has seriously damaged the normal production of the
masses, life, restricting the development of Pingdingshan coal mine economy. In this paper, the
geological disasters such as ground collapse, ground fissures and ground subsidence in Pingdingshan coal
mine are analyzed, and the degree of geological disasters in the mining area is analyzed in combination
with the severely affected mining area. Finally, reasonable and feasible countermeasures have been put
forward.
Kelud volcano is located in East Java Province, Indonesia. According to Geochemical study of
Kelud Volcano, it could be divided into 3 periods which are Kelud I (older than 100 ky BP), Kelud II (40 – 100
ky BP), and Kelud III (younger than 40 ky BP). A specific petrogenesis of Kelud are dominatad by magma
mixing and fractional crystalization. New petrological data from Kelud volcano was taken through products of
the eruption in 1990 (Vulkanian type), 2007 (Lava plug forming) and 2014 (Plinian type). Petrographic study
on these rocks showed that reverse and oscilatory zoning on plagioclases, Shieve-like and corroded textures on
plagioclases and pyroxenes are common. However, normal zoning textures were also found on plagioclases and
pyroxenes. Whole rock study on these rocks showed all rocks were classified into Basalt to Andesite in
composition with calc-alkaline group. The study indicated that their magma origin derrived from slab with
fractional crystallization during in the magma reservoir, and magma mixing processes are dominant expecially
in magma pockets. Concequently, the magma origin and petrogenesis of Kelud magma after the 1966 eruption
are still the same as those of old magma of Kelud.
Black cotton soils are among a group of soils termed as problematic soils. These soils have
undesirable characteristics in relation to construction works and therefore need some form of improvement
when encountered in construction projects. Techniques for improvement of black cotton soils include
replacement, moisture control or adding a stabilizer. Cement and/or lime has been commonly used in soil
stabilization for ages. However, due to the associated cost, required quality control and the need to utilize waste
materials in construction, new stabilizing materials are emerging. This paper presents a study on application of
quarry dust for improving properties of black cotton soil in Mbeya region, Tanzania. The targeted improvement
was to achieve minimum acceptable characteristics for road subgrade as per Tanzania standards. It was
determined that 40% by weight of quarry dust added to the black cotton soil was able to improve the
characteristics by increasing CBR value from 3.8 to 15.7 and reducing PI from 32% to 15%. It will be worthy
studying the cost implication of the suggested improvement in relation to other techniques before application of
the study findings.
High intensity rain and morphometri in Padang city cause at Arau. Morphometri
geomorphologi that is related to wide of, river network, stream pattern and gradien of river. The form wide
of DAS will be by stream pattern and level.This will influence to the number of rain. Make an index to
closeness of stream depict closeness of river stream at one particular DAS. Speed of river stream influenced
by storey, level steepness of river. Steepness storey, level is comparison of difference height of river
downstream and upstream. Ever greater of steepness of river stream, excelsior speed of river stream that
way on the contrary. High to lower speed of river stream influence occurence of floods, more than anything
else if when influenced by debit big. By using rainfall from year 2005 to year 2015, and use Thiessen method
got a rainfall. Use the DEM IFSAR, analysed sofware ARGIS, and with from earth map, the result got DAS
in at condition of floods gristle and sedimentation. There are band evakuasi for resident which data in
floods area.
The chemical (extractives and lignin) content and histological property (microscopic structure)
of tissues of Ricinodendron heudelotii (Baill, Pierre ex Pax), an angiosperm, were investigated for its potential
as a fibrous raw material for pulp and paper production. Bolts of about 70 cm were cut from the felled trees at
three different merchantable height levels of 10%, 50%, and 90% to obtain: corewood, middlewood and
outerwood samples. The fiber characteristics of the selected trees viz: the fiber length, fibre diameter and lumen
diameter were measured while the cell wall thickness was derived from the measured fibre dimensions. The
average fiber length, cell wall thickness, and lumen width, were 1.40 mm, 4.6 µm, and 32.3 µm, respectively.
The extractive and lignin contents were determined. Klason lignin content was about 30%. Extractive content of
R. heudelotii ranged from 0.41 to 0.5%. Based on these findings R. heudelotii is suitable for pulp and paper
production.
The prolific Niger Delta Basin is a mature petroleum province. Therefore, further prospectivity in
the basin lies within deeper plays which are high pressure and high temperature (HPHT) targets. One of the
main characteristics of the Niger Delta is its unique diachronous tripartite stratigraphy. Its gross onshore and
shallow offshore lithostratigraphy consists of the deep-seated Akata Formation and is virtually exclusively
shale, the petroliferous paralic Agbada Formation in which sand/shale proportion systematically increases
upward, and at the top the Benin Formation composed almost exclusively of sand. This stratigraphic pattern is
not exactly replicated in the deep offshore part of the delta.
A low-carbon steel wire of AISI 1022 is used to easily fabricate into self-drilling tapping screws,
which are widely used for construction works. The majority of carbonitriding activity is performed to improve
the wear resistance without affecting the soft, tough interior of the screws in self-drilling operation. In this
study, Taguchi technique is used to obtain optimum carbonitriding conditions to improve the mechanical
properties of AISI 1022 self-drilling tapping screws. The carbonitriding qualities of self-drilling tapping screws
are affected by various factors, such as quenching temperature, carbonitriding time, atmosphere composition
(carbon potential and ammonia level), tempering temperature and tempering time. The quality characteristics of
carbonitrided tapping screws, such as case hardness and core hardness, are investigated, and so are their
process capabilities. It is experimentally revealed that the factors of carbonitriding time and tempering
temperature are significant for case hardness. The optimum mean case hardness is 649.2HV. For the case
hardness, the optimum process-capability ratio increases by about 200% compared to the original result. The
new carbonitriding parameter settings evidently improve the performance measures over their values at the
original settings. The strength of the carbonitrided AISI 1022 self-drilling tapping screws is effectively improved.
More from International journal of scientific and technical research in engineering (IJSTRE) (20)
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The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
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Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
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china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
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Improving Quality of Service in GSM By Reducing Probability of Call Blocking Through Network Dimensioning Using Erlang B Model and Congestion Control Algorithm
1. International journal of scientific and technical research in engineering (IJSTRE)
www.ijstre.com Volume 2 Issue 6 ǁ June 2017.
Manuscript id. 778715524 www.ijstre.com Page 1
Improving Quality of Service in GSM By Reducing Probability of
Call Blocking Through Network Dimensioning Using Erlang B
Model and Congestion Control Algorithm
AHUCHAOGU NNAMDI1
EZEKIEL NNAMERE ANEKE2
PROF.EKE JAMES3
1
Ph.d Scholar, 2
Ph.d Scholar, 3
Supervisor
Department of Electrical and Electronic Engineering
ESUT, Enugu Nigeria.
08037856230, 08038901196, 08037782812
ahuchaogun@yahoo.com,aneke.ezekiel@gmail.com,ENG.Ezekiel.Aneke@ieee.org
ABSTRACT : Call blocking probability is a key performance metric for any telecommunication protocol.
Unexpectedly, the level of patronage being experienced in Global System for Mobile Communication (GSM) in
Nigeria is overwhelming. This is as a result of freedom of calling from anywhere at any time and clarity of the
voice enjoyed in GSM since it is on a digital technology platform. This has brought a lot of congestion in the
network resulting in poor services by the operators. This research has developed a control algorithm for the
management of the congestion experienced in the GSM network in Nigeria. It explores the use of Erlang-B in
determining the appropriate probability level for some range of subscribers. Thereafter, when there is
congestion, block time sharing, dynamic allocation without time slicing, dynamic allocation time slicing with
signal sensing, frequently recent call allocation, and priority allocation algorithms were developed to manage
the congestion. Furthermore, a hybrid algorithm was developed that integrates all the algorithms together in
other to manage the congestion considering all the strengths and constraints of each algorithm. If the
recommended congestion management algorithm is followed comprehensibly, the congestion problem on the
GSM network will be reduced drastically which in turn reduces call block. Also, from the research conducted by
NCC and others in quest for ameliorating the call block problem, it was noted that from the average number of
subscribers that dialed up to three or more times before getting connected, 58% of call blocking rate was
recorded which after using more number of timeslots (which depicted more available channels) in this work was
reduced as showed in the simulation results and will also be reduced the more using the developed congestion
control algorithm technique. The simulation codes and program are shown on the appendix in chapter five.
I. INTRODUCTION
1.1 BACKGROUND OF THE STUDY
From time immemorial, information and communication have formed the basis of human existence. Before the
advent of GSM in Nigeria, telephones were luxury that only a few privileged Nigerians enjoyed.
However, with the advent of GSM in Nigeria in August 2001, mobile telephony has rapidly become the most
popular method of voice communication in the country. Its growth has been so rapid that Nigeria has been
rightly described in various media as one of the fastest growing GSM market in the world.
The first generation of cellular telephone system, which was analog system, launched in 1960s had the
limitations of incompatibility among the various analog system available amongst other limitations which led to
the invention of second generation digital system called GSM with a wide spectrum allocation.
Following the rollout of GSM services across the nation, the socio-economic landscape of Nigeria has been
positively altered. Its explosive growth has brought huge revenues to the operators as well as the government
through tax and license fees.
Similarly, the citizenries have benefited immensely from the services not only as a means of communication,
but it has provided job opportunities for thousands of people.
However, the principal development that mars these benefits is the aggressive complaining raised by GSM
subscribers regarding to the abysmal quality of service (Qos) rendered by the GSM operators in the country. The
unfortunate aspect of this evil is the fact that all the GSM subscribers irrespective of the operator are being
affected. Based on this ugly experience, this research study was focused on the causes of the problem and ways
of ameliorating the observed defects. Generally, there are five frequency bands designated by international
Telecommunications Union (ITU) for the operation of the GSM mobile phone: GSM-400, GSM-850, GSM-
900, GSM-1800 and GSM-1900.
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In Nigeria, GSM-900 and GSM-1800 are being used. Here, GSM-1800 uses 1710-1785 MHZ to send
information from the mobile station to the base transceiver station (uplink) and 1805-1850MHZ for the other
direction (downlink). Also, GSM-900 uses 890-915 MHZ for the forward or uplink direction while the reverse
or downlink direction is on 935-960 MHZ full details on other GSM frequency bands using across the world is
shown in table 1 below.
Table 1.1 World-Wide GSM frequency B and
System B and (MHZ) Uplink (MHZ) Downlink (MHZ)
GSM-400 450 4504-4576 460.4-4467
GSM-400 480 478.5-486.0 488.8-496.0
GSM-850 850 824.0-849.0 869.0-894.0
GSM-900 900 890.0-915.0 935.0-960.0
GSM-900(£.GSM) 900 880.0-915.0 925.0-960.
GSM-900(R-GSM) 900 876.0-880.0 921.0-925-0
GSM-1800 1800 1710.0-1785.0 1805.1880.0
PCS-1900 1900 1850.01910.0 19300-19900
The method of sharing the radio spectrum bandwidth ofGSM is known as Time- and Frequency-Division
Multiple Accesses (TDMA and FDMA). FDMA part involves the division by frequency of the maximum 25
MHZ bandwidth into 124 carrier frequencies spaced 200 KHZ apart (Harte et al, 1999). The actual number of
carrier in GSM is 125 but due to interference to other systems, the very first carrier is not used thus reduced the
carrier to 124. One or more carrier frequencies are allocated to each base station. Each of these carrier
frequencies is then divided in time, using TDMA scheme into 8 timeslots as seeing in fig 2.0. Each of these
timeslots is a physical channel occupied by an individual user (carries control and a traffic data in a burst form)
(Mehrotra, 1997). Typical GSM handsets carrier channel, thus allows up to eight users to simultaneously share a
single radio channel.
Figure 1. GSM Duplex Radio (Source: Mehrotra, 1997)
The management of this radio frequency among subscribers remains a problem all over the world including
Nigeria. A lot of literatures have been written in respect of this problem (Gupta and Sachan, 2007; Candan and
Salamah, 2006). The congestion experienced today is a result of this problem at hand. This research took a
critical look at the GSM network in Nigeria and come up with algorithms that can be adapted on the GSM
network to minimize this congestion.
However, the data from the present study is compared with the results of the previous studies in order to
ascertain the accuracy of the work.
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1.2 STATEMENT OF PROBLEM
With the poor and epileptic quality of services presently rendered by GSM operator in Nigeria, it is possible that
in no distance time, a GSM subscriber of a particular network operator may not be able to get or established a
communication link with another subscribers from another network if nothing is done about it.
1.3 OBJECTIVES OF THE STUDY
This research work had some of its objectives to include:
To find the causes of call blocks
To analyse network congestion and its causes relating to call blocking
To obtain rate of setting up a call
To find the causes of unsuccessful call handovers
Relating to call blocking
To obtain call completion success rate.
To determine the appropriate probability level for range of network subscribers using Erlang B
model.
To develop an Algorithm for management of network congestion.
1.4 SIGNIFICANCE OF THE STUDY
It is clear and obvious that quality of service is an important key performance indicator (KPI) that is used in
determining the efficiency of an industry in terms of services rendered, so that of the telecommunication
industry cannot be left out. And for the consumers in the industry, it is expected that maximum satisfaction be
derived from any services paid for, therefore, the activities of the GSM operators in the country should always
be monitored by government and the GSM operators themselves should wakeup in the areas of quality of signal.
This problem, if ignored, might increase the difficulty in inter-Network connectivity, affect the social security of
the country negatively and break the minimum performance levels jointly agreed between GSM operators in
Nigeria, consumer representatives and NCC.
1.5 SCOPE AND LIMITATION OF STUDY
To be sincere, a lot of issues and problems were encountered in the process of information gathering during this
research work which include, disruption of movement as a result of bad road, withholding of information by the
relevant agencies amongst other factors too. Also this research work mainly focused on call block problems and
its ways of reduction as a key player in quality of service assessment in communication industries.
II. LITERATURE REVIEW
2.1 INTRODUCTION
Following the effort to find the solution to the poor quality of services provided by GSM operators in Nigeria,
Nigeria Communication commission, the body responsible for regulation of GSM operation in Nigerian carried
out a research in 2005 to find causes of the problems and ways of ameliorating it.
This research was centered on customer’s complaints method through the use of questionnaire. The
investigation was conducted for period of 4 months (May 2005-August 2005) in the country federal capital
Territory (FCT) and some other selected cities in all the six geo-political zones (North-West, North-Central,
North-East, South-West, South-South and South-East) of the country, where all of the three major GSM
networks considered were operating. The GSM network studied are Celtel, MTN and GLO. The study was
conducted using structured questionnaire. The primary data obtained from this investigation was later compared
with secondary data from other previous related studies.
2.2 STRUCTURE OF THE QUESTIONNAIRE
This involved the designing and administering of the well structured research questionnaire to the customers of
the three GSM networks in the studied areas. The questionnaire was divided into two sections.
The first section is the introductory part, where the aim of the study was stated. This section also contains words
of assurance and encouragement, assuring respondents that the information provided by them would be treated
with utmost confidentiality.
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The second section of the questionnaire consists of questions related to objectives of the study. The section was
divided into four subsections. The first subsection contains four questions on NETWORKACCESSIBILITY.
Questions on call set up rate such as how easy is it to set up call, number of attempts they do make before
having a successful call, etc were asked.
In the second subsection, questions on retainability on the network after successful call set up were asked.
Question such as how often do they experience call termination before completing their conversation were
asked. Two questions were asked in this subsection from which service retainability degree of each of the three
networks studied were evaluated.
The third subsection contains three questions on the correction quality or service integrity of each of the
networks considered. Questions on voice quality and SMS delivery of each operator were asked.
In the fourth subsection, two questions were asked on network coverage or network availability of the three
GSM operators. In all, a total of eleven questions were asked, which were structured in such a way that one
question leads to the next.
FIGURE 2.1 Call setup success Rate (Easy/Difficult)
Figure 2.1 shows the rate of call setup or accessibility to each of GSM network. CSSR (E) means easy call setup
rate while CSSR (D) means difficult call setup rate. The figure 2.1 shows that among the three GSM operators
studied, Glo has the highest easy call setup success rate, while Airtel has the lowest easy call setup success rate.
This implies that, the accessibility of MTN is easier than that of Airtel.
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Figure 2.2: Number of dials before call setup.
The degree of accessibility of figure 2.2, which indicates the number of attempts a caller makes before a call can
be established. From the figure it was found for every 100 calls made on the Airtel network, there is high
probability of having 47 success calls with the first or second dials while 51% of those successful calls only
occurred with three or more numbers of attempts on Airtel networks. The figure reveals that accessibility to
both Glo and MTN network can be accomplish with fewer number of attempt.
2.3 ADMINISTRATION OF THE QUESTIONNAIRE
This phase of the work was carried out in the selected areas in the FCT and some cities in each of the six geo-
political zones where the three GSM operators are operating.
Table I shows the detail on the retrieved questionnaires from each of the studied areas. The responses gathered
were converted to percentage so that the result analysis can be on the equal basis.
Table 2.1 Questionnaire distribution
GSM NETWORK
ZONE CELTEL MTN GLO
North-West 1060 1383 699
North-Central 559 11208 840
North-East 476 364 253
South-West 839 1074 534
South-South 832 1774 677
South-East 229 419 768
FCT Abuja 473 587 506
Total 4468 6807 4277
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2.4 CALL SET UP FAILURE:
This an important parameter used in determining network accessibility. It is the ability of a subscriber to initiate
a call and granted access. Technically, during a GSM call setup, a speech call is assigned from a SDCCH (Stand
alone dedicated channel) to a TCH (traffic channel). If the TCH selected suffers from interference, then the
assignment will fail. And assignment failure message will be sent to the MSC. The call will then be re-
established back. According to the survey carried out by NCC, all the three major operators were found to
perform poorly in the area of number of times that users dial before connection is made. The survey shows that
only less than half of the subscribers on each of the networks do get their calls through on the first or second
dial. (Airtel-49%, MTN-46%, GLO-47%).
In other words, subscribers 3 times or more were (Airtel-49%, GLO-50%, MTN-50%). Results of sampled
opinion are as shown in table below.
Table 2.2 showing subscribers dialing 3 or more times before getting connected.
CITY AIRTEL % MTN % GLO %
Abuja 56 63 67
Kaduna and Zaria 39 50 45
Maiduguri 61 53 39
Kano 41 42 53
Jos 33 38 48
Bauchi 57 68 49
Ibadan 46 41 42
Calabar 45 79 50
Port Harcourt 4 47 20
Owerri 63 54 45
Enugu 37 59 61
Benin 51 60 58
Lagos 35 39 50
Kwara 46 36 33
AGGREGATE, AIRTEL =47%, MTN = 50%, GLO = 49%
Table 2.3: Showing subscribers connected to numbers not dialed.
CITY AIRTEL % MTN % GLO %
Abuja 67 60 60
Kaduna and
Zaria
29 67 59
Kano 74 77 73
Maiduguri 47 34 34
Jos 57 64 74
Bauchi 32 36 58
Calabar 65 59 75
Owerri 52 62 51
Enugu 69 57 60
Benin 62 71 70
Port
Harcourt
84 78 79
AGGREGATE, AIRTEL =64%, MTN = 67%, GLO = 64%
2.5 CALL RETENTION/CALL DROP:
Call retention is the ability to retain a GSM call after it has been established while dropped call is a situation
where by an established call is abruptly terminated while conversation is ongoing. It is a common occurrence in
Nigeria GSM system that communication is terminated unexpectedly while conversation is on-going.
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Figure 2.3: Call drop and call completion success rate.
In all the networks considered, it was found that 36% is the maximum CCSR value the subscribers do
experience. This implies that for every 100 successful call setup, only 36 of them will not drop before the parties
completed there conversation. The value reveals that the retainability on all the three GSM network is low. This
is an indication that their services are unreliable and unsatisfied
A survey conducted by NCC recently clearly showed that one of the most important customers perceived
problems that affects quality of service is in the area of dropped calls. This is as depicted in table 2.4 below.
Table 2.4: Summary of Dropped calls and their locations
CITY AIRTEL % MTN % GLO %
Abuja 67 69 60
Kaduna and
Zaria
29 67 59
Kano 74 77 73
Maiduguri 47 34 34
Jos 57 64 74
Bauchi 32 36 58
Calabar 65 59 75
Owerri 52 62 51
Enugu 69 57 60
Benin 62 71 70
Port Harcourt 84 78 79
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AGGREGATE, AIRTEL =64%, MTN = 67%, GLO = 64%
CONGESTION: Congestion is a phenomenon in telecommunication system that occurs when more subscribers
attempt simultaneously to access the network than it is able to handle. This is a situation where subscriber’s
numbers has completely overgrown network capacity.
In quest to find a lasting solution to the poor quality of services rendered by GSM operator in Nigeria, some
scholars and agencies have made some researches and suggestions which when applied could not solve the
problem completely because of one or two factors that wasn’t put into consideration.
Adegoke A.S and Babalola I.T of the department of Electrical Engineering, Yaba College of Technology, in
2008, conducted a research on quality of service assessment.
In their, work they made use of NETWORK STATISTICS as the mechanism to monitor, analyze and evaluate
quality of service.
Here, hypothesis tests were considered to compare network operator’s performance. For this purpose, two
different hypothesis testing methods were conducted. These were based on classical statistical approaches,
namely chi-square (X2
) and fisher’s exact test. By this way, firstly contingency tables were obtained. Then, by
using chi-square distribution, hypothesis tests were derived to compare network operator’s performance.
Lastly, hypothesis test were repeated using fishers exact test which is a reliable method if the sample sizes are
small.
2.6 CHI-SQUARE HYPOTHESIS TESTING METHOD
Chi-square distribution is one of the most widely used probability distribution in inferential statistics, e.g in
hypothesis testing, or in construction of confidence intervals. The chi-square distribution is the distribution of a
sum of the square of K independent standard normal random variables. In many problems, it is not assumed that
the available observation come from a particular parametric family of distributions. The chi-square test is widely
used in the cases where no special assumptions are made about the form of the distribution. In chi-square test
conducted for speech comparison of networks, contingency tables were generated to examine dependency of the
networks. It is known that a contingency table, as it is typically represented by a table having R rows and C
columns(R X C), is a tabular arrangement of count data representing how much row factor are related to the
column factor.
In this study, samples from the three networks are selected at randomly. Efforts focuses on assessing paired
observations (number of good speech sample /number of samples), and the reports the results in a 2X2
contingency table that are independent of each, as discusses in several works in the literature.
In other to define number of good sample, a threshold value is needed. This value indicates the minimum quality
of speech perceived by users (PESQ) value that represents the acceptable speech quality. Thus, for set of speech
samples, each sample is compared with the threshold and then good samples among the total number of sample
can be obtained. Three different contingency tables were constructed since the tests are performed two by two,
pair of the networks or operators. That is, operator A is compared with B and then operator C separately, and
finally operator B is compared with operator C. Constructed contingency tables are shown in table 2.5.
Table 2.5: Contingency Tables for Operators.
Operator A&B Operator A&C Operator B&C
A B A C B C
Good
sample
7955 8892 7955 8247 8892 8242
Total 8984 9653 8984 9430 9653 9430
Where:
A= AIRTEL GSM Operator
B=MTN GSM Operator
C=GLO GSM Operator
On the basis of these contingency tables, the hypothesis
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HXY, says that the performance of network X does not differ significantly and is not independent of network Y
while H’XY says that the performance of network X differ significantly and is independent of network Y. In the
case of 2X2 contingency, the x2
is calculated from the following expression.
X2
=(Nx+Ny) (KyNx-KxNy)2
NxNy (Kx+Ky) (Nx+Ny-Kx-Ky)…………………………..2.1
Where N denotes the total sample number and K denotes the good sample number for network operators X and
Y. For instance, for the contingency table between network operator A and B, NA represents the total sample
size of network operator A (9880) while KA represents the good sample size (7955). Thus, x2
test are applied
accordingly, and result provided in table 2.6.
TABLE 2.6 TEST RESULT FOR THE NETWORK
OPERATORS X2
AIRTEL & MTN 68.3
AIRTEL & GLO 0.0021
MTN & GLO 113.29
Now, for testing the hypothesis, a threshold for the test statistics is determined as 3.841 where chi-square with 1
degree of freedom at 0.95 is assumed (significance level of 0.05). Then, for example, for networks X and Y,
HXY is rejected if the test statistics exceeds this threshold. Accordingly to the test results in table 2.6 HAIRTEL/ MTN
and HMTN/GLO are rejected where as HMTN/GLO is accepted. Thus, it is concluded that the performance of MTN
network operator is independent of the other two network operators. On the other hand, the performances of
AIRTEL and GLO network operators are not significantly independent.
X2
test is a reliable test in this research since the number of observations exceeds 5 in the above contingency
tables, however, if the sample sizes are small, fisher’s exact test could be used as a statistical significance test in
the analysis of contingency tables.
2.7 FISHER’S EXACT TEST
Fishers test is one of the exact test as the significance of the deviation from a null hypothesis can be calculated
exactly. Then the hypothesis tests where repeated using fishers exact test. Accordingly the probabilities P, for
the contingency table are calculated from:
Nx Ny
KX KY
P = …………………………………………………2.2
NX + NY
Kx + Ky
And the results are listed in table 2.7
Table 2.7 Probabilities for the contingency table using Fishers test.
NETWORK OPERATORS P
AIRTEL & MTN 0.52
AIRTEL & GLO 0.5
MTN & GLO 1
As can be seen from table 2.7, calculated probabilities are not less than the significance level (0.05). Then
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HAIRTEL& MTN, HAIRTEL&GLO and HAIRTEL&GLO are not rejected.Thus, it is concluded that the performance of networks
AIRTEL, MTN and GLO are independent. Then, according to x2
test, all networks can be compared in pairs and
if the performance differs significantly, they receive one point.
Summarily, the information gotten from the research conducted by the Nigerian communication commission
may not been seen as being validated enough considering the fact the questionnaire method is not an acceptable
scientific method of problem evaluation and analysis.
III. METHODOLOGY, DESIGN AND IMPLEMENTATION
3.1 RESEARCH METHODOLOGY
Quality of services (Qos) can be described as the ability of a network to provide a service at an assured service
level. This can be measured by either the network operators by itself or by an independent or a regulatory
organization.
In order to study the performance of the proposed method, different sets of data were generated using the Erlang
B formula.
In this research work, finite numbers of subscribers were used in loading the network channel using the Erlang
B formula. These numbers of subscribers were used together with various allocation time of service period of 60
seconds, 120 seconds, and 180 seconds respectively.
The range of subscribers chosen for this work includes 200, 250, and 280 numbers of subscribers.
The dimensioning was based on the loaded Erlang B formula.
3.2 Call Blocking : This is complete denial of a customer’s call resource access to the network after a request
has be made due to unavailable or busy channels.
The major causes of blocked calls is Network Congestion, and adjacent and co-channel interferences, under
which every other factors or cause are attached to.
Each base station has certain fixed number of channel available to carry data traffic. If any new call arrives to a
base station, it will first check for the availability of a free channel. If a free channel is are available, then this
free channel is allocated for the call, but if there is no free channel available, then the call is blocked.
The amount of blocking can be reduced by changing or adjusting the capacity of the network in a way that more
communication channels are made available in locations with higher user density.
In GSM Communication, resources are shared in terms of Time and Frequency i.e (Channelization Access
Protocol).
Network dimensioning could be said to be the allocation of time and frequency to the users of a particular
network channel to reduce congestion.
It is used to determine the amount of traffic the radio channel capture. An accurate traffic model for the system
will greatly enhance the accuracy of network dimensioning, extending network investments and increasing the
profit returns. When a network is properly dimensioned, the channels will be used more efficiently and will
produce greater user satisfaction.
On the other side, poor modeling of network traffic characteristics can actually affect system performance.
Improper dimensioning of network will lead to congestion in the cell, which will also lead to increased blocked
calls, increased unsuccessful handovers and poor call accessibility and retainability.
Traffic planning focuses on the busy hour, which is for effective traffic management. For the purpose of this
work, Network Dimensioning here relied on Erlang B formula for its mathematical models.
Network Accessibility:- This is the probability that a service can be obtained within a given conditions when
requested by a service user. In other words, it measures the ease in which calls are established (i.e the call set up
success rate (CSSR). It denotes that, the higher the value of CSSR, the easier it is to set up a all.
It is measured by the ratio of the number of successful calls (#SC) in the tests to the number of call attempts
(#CA).
i.e Accessibility = #SC = (1- Blocking probability) x 100%.....3.1
#CA
Call Setup Traffic Channel (TCH) Congestion rate: The call Setup Traffic Channel Congestion Rate
provides the percentage of call attempts to allocate a TCH call setup that were blocked in cell.
Call Setup TCH Congestion Rate = No of TCH blocking …… 3.2
No of TCH attempts
Possible reasons for call setup block could be:
Increasing Traffic Demand.
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Bad Dimensioning.
High Antenna Position.
High Mean Holding Time.
Low Handover Activity.
Congestion in Surrounding Cell.
3.3NETWORK CONJECTION: Congestion is a phenomenon in telecommunication system that occurs when
more subscribers attempts simultaneously to access the network than it is able to handle. This is a situation
where subscriber’s number has completely overgrown network capacity.
The problem of network congestion is a network managerial issue that affects the quality of service (Qos)
rendered by a network, apart from the fact that over utilization of a node in network can lead to resources short
span or malfunctioning. Therefore congestion control is of utmost importance for the sustainability of the
system and the development of congestion control measure in this system should be a good effort in the right
direction.
REASONS/CAUSES OF NETWORK CONGESTION ARE:
Lack of adequate infrastructure: To guarantee efficient network quality, there must be adequate
infrastructural equipments to be able to drive the network. Also, the size of these equipments must be in tandem
with the subscriber’s base. When subscriber’s base overgrows infrastructural equipment, the congestion is
inevitable. In Nigerian situation, operators have been playing down on expansion of all cell sites, which of
course is the strength of call quality. The rate of service rollout in the country has never been the same with rate
of infrastructural roll out, and this often leads to network congestion and inability to recharge phones.
● Insufficient channels: Since there are not enough infrastructural equipments (e.g base stations), automatically
there will be lack of adequate network channels to support network functionality. Recall that channels are
normally used to determine total number of subscribers that can be allowed to use a base station.
Improper network configuration: The network configuration not being set up properly, such that
one cell is not aware of the cell the phone is trying to handover to.
3.4 HANDOVER (HANDOFF): This is the process of transferring a call (or data transfer) in progress from one
channel (base station) to another.
During handover processes, handoff calls could be blocked as a result of non availability of channel to
accommodate such. This in turn could cause call dropping.
Handover success rate is one of the major key performance indicator (KPI) that should be optimized to improve
handover quality. It shows the percentage of successful handovers of all handover attempts. A handover attempt
is when a handover command is sent to the mobile .
Possible reasons for poor handover success rate could be:
Congestion
Poor Link Connection.
Bad Antenna Installation .
Incorrect Handover Relations.
Incorrect Locating Parameter Setting.
Bad Radio coverage.
REASONS/ CAUSES OF HANDOVER
If the mobile device moves out of the range of one cell (base station) and a different base station
can provide with a stronger signal.
If all the channels of one base station are busy then a nearby base station can provide service to the
device.
TYPES OF HANDOVERS
Hard Handover (for GSM system)
Soft handover (for CDMA systems)
N.B for a handover process to be successful means that there will not be a break of radio link for cell-to-cell
transfer of call.
3.5 ERLANG B FORMULA
This formula could be used to dimension a GSM Network so as to increase the network retainability, call
accessibility, handover success rate, thereby reducing the call block occurrences.
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3.7 Loading Channel Using Erlang B Formula
For the purpose of this research work, three case studies are used using Erlang formula to determine the
accepted loading for this model.
Loading: This refers to the total number of subscribers a channel is expected to serve: A loading of 200
subscribers means, the channel is expected to serve 200 subscribers.
For this work, we assumed a loading values of 200, 250, and 280. Also, we assumed a timeslot of 8, and a
variable service time of 60 seconds, 120 seconds, and 180 seconds respectively. The loading technique was also
repeated using the same values for the variables with a timeslot of 16, and MATLAB software as shown in
chapter four and five were used to generate the simulation parameters in all the processes.
3.8 SIMULATING THE PROCESSES
Simulation One:
Inputting the following values into MATLAB using equations (3.5)and(3.6) respectively generated the
parameters for simulation one as shown in table 4.1 and plotted the graph shown in figure 4.1(a&b).
i.e N = 200, 250, 280
n = 8
m = 60
Simulation Two:
Also by inputting the following values into MATLAB using equations (3.5)and(3.6) respectively generated the
parameters for simulation two as shown in table 4.2 and plotted the graph shown in figure 4.2(a&b).
i.e N = 200, 250, 280
n = 8
m = 120
Simulation Three:
Also by inputting the following values into MATLAB using equations (3.5)and(3.6) respectively generated the
parameters for simulation three as shown in table 4.3 and plotted the graph shown in figure 4.3(a&b).
i.e N = 200, 250, 280
n = 8
m = 180
Simulation four:
Inputting the following values into MATLAB using equations (3.5)and(3.6) respectively generated the
parameters for simulation four as shown in table 4.4 and plotted the graph shown in figure 4.4(a&b).
i.e N = 200, 250, 280
n = 16
m = 60
Simulation five:
Inputting the following values into MATLAB using equations (3.5)and(3.6) respectively generated the
parameters for simulation five as shown in table 4.5 and plotted the graph shown in figure 4.5(a&b).
i.e N = 200, 250, 280
n = 16
m = 120
Simulation six:
By inputting the following values into MATLAB using equations (3.5)and(3.6) respectively generated the
parameters for simulation six as shown in table 4.6and plotted the graph shown in figure 4.6(a&b).
i.e N = 200, 250, 280
n = 16
m = 180
3.9 DEVELOPED MODELS FOR MANAGING NETWORK CONGESTION
Below shows the model that could be used to manage the congestion that might result from the loading model
chosen or other unexpected sources.
a. Block time sharing: Here, each call is given a specific time of block and until the time expires,
no other call can use the channel. Each call is given full access to the network system according to the
time allocated but as soon as the time expired, a control is passed to pre-empt the call as to allow other
callers to have access to the channel.
Advantages of this method are:
It does not allow any call to a channel more than the allowed time.
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It also gives access to the call without interruption from any other call within the time limit.
It allows equal sharing among the call.
Its DRAW BACK is that it wastes service time. For those calls that do not finish their allotted time before they
exit the channel, the remaining time will be wasted.
Below shows the algorithm using pseudo code that could be used to achieve the process:
1. START
2. SET THE BLOCK TIME
3. DO WHILE SERVICE= TRUE
4. SET K=1 // INITIAIISING TIMESLOT
5. DO WHILE NOT FREE AND K<=8// TESTING FOR FREE TIMESLOT
6. R = K + 1
7. LOOP
8. IF TIMESLOT= FREE THEN
9. LOAD THE CALL TO TIMELSLOT (TK)
10. WHILE SERVICE TIME < BLOCK TIME OR SERVICE TIME < AIR TIME
11. CONTINUE THE CALL
12. ELSE
13. REJECT THE CALL
14. END IF
15. FETCH THE NEXT CALL
16. LOOP
(b) Dynamic Allocation without time slicing. This will allow calls to occupy the channel without given any time
range. Any call that enters the channel will finish its work before allowing any other call to the channel. Also, it
allows any call that is ready to seize the channel without any consideration.
The advantage of this method is that it allows the call to finish its work before any other call can be allowed to
the channel.
The drawback is that, sometimes, some calls might occupy the channel unnecessarily thereby denying others
from entering.
The following algorithm could be used to achieve this;
1. START
2. DO WHILE SERVICE= TRUE
3. SET K=1 // INITIAIISING TIMESLOT
4. DO WHILE NOT FREE AND K<=8// TESTING FOR FREE TIMESLOT
5. K = K + 1
6. LOOP
7. IF TIMESLOT= FREE THEN
8. LOAD THE CALL TO TIMELSLOT (TK)
9. WHILE SERVICE TIME <AIR TIME
10. CONTINUE THE CALL
11. ELSE
12. REJECT THE CALL
13. END IF
14. FETCH THE NEXT CALL
15. LOOP
( c) Priority Allocation
In this method, everybody should have a level of priority and this priority should have been integrated into the
SIM card.
So, anytime anybody buys a SIM card and activate it on the network, the priority level registered automatically.
The priority level will be used throughout the period of subscription of the subscriber to the network. The level
of priority will be determined by the network of your service. This model will be able to take care for the
executive essential duties officers like president, Governors, fire fighters, police and so on.
In this model, the principles of arithmetic operation preferences will be used where the highest priority will
again access to the channel before the lower priority.
So this model is meant especially for essential duties officers. In this model, time interrupt pre-emption will not
be applied; their access to the network will not be terminated until they terminate it themselves. The advantage
of this model is that it will allow the essential duties officers calls to complete their calls without any interrupt
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and thereby forestalls causalities that might occur if they were not given attention. The DRAW BACK of this
method is that many calls will be denied access during the time when the essential duties are on. Also, some
calls that may be very important to some subscribers might be dropped and immediate attention may not be
possible easily.
Below shows the algorithm to achieve that:
1.START
2. DO WHILE SERVICE= TRUE
3. SET ESSENTIAL CODES
4. SET K=1 // INITIAIISING TIMESLOT
5. DO WHILE NOT FREE AND K<=8// TESTING FOR FREE TIMESLOT
6. K = K + 1
7. LOOP
8. IF TIMESLOT= FREE THEN ESSENTIAL CALL
9. DROP CALL WITH LEAST PRIORITY
10. LOAD THE ESSENTIAL CALL TO TIMESLOT (TK)
11. WHILE SERVICE TIME > 0
12. CONTINUE THE CALL
13. ELSE
14. LOAD THE CALL TO TIMESLOT (TK)
15. WHILE SERVICE TIME > 0
16. CONTINUE THE CALL
17. WEND
18. END IF
19. FETCH THE NEXT CALL
20. LOOP
(d) Dynamic Allocation Time Slicing with Signal Sensing: This allows calls to occupy the channel with a
maximum time interval. This will allow calls to occupy the channel with an attach time range. Unlike the block
time-sharing, it will not preempt the calls automatically but a carrier sense will be passed at intervals to check if
there is any call waiting. If there is any call waiting, then, the signal will preempt any call that had exhausted its
maximum time allocation, other- wise, the call will be allowed to continue as long as the caller wishes to
continue. The advantages are:
• It does not allow the system to be occupied unnecessarily.
• It allows the subscriber to continue calling as long as they wish provided there is no call waiting.
The disadvantage is that it does not consider any call as important thereby essential calls will be pre-empted
without finishing the call. Below shows the Algorithm:
1. START
2. SET THE MAX_TIME
3. DO WHILE SERVICE = TRUE
4. SET K = 1// INITIALISING THE TIMESLOT
5. DO WHILE NOT FREE AND K<=8
6. //TESTING FOR FREE TIMESLOT
7. K = K+1
8. LOOP
9. IF TIMESLOT = FREE THEN
10. LOAD THE CALL TIMESLOT (TK )
11. WHILE SERVICE_TIME < MAX_TIME AND NO CALL WAITING OR SERVICE_TIME < AIR_
TIME CONTINUE THE CALL
12. WEND
13. ELSE
14. REJECT THE CALL
15. END IF
16. FETCH THE NEXT CALL
17. LOOP 5
(e)Hybrid Algorithm: This takes into account the strengths and constraints of all other network management
Algorithms. The steps below are recommended as general order for introducing the different solutions in the
network layer:
The first step is to determine the appropriate channel loading model for the network. Make sure the number of
channels to subscribers does not result into the operator’s deficit. Then the below algorithm should be used to
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manage calls within the network. The recommended algorithm has a prioritization scheduled to maintain un-
interrupted communication during emergency. It also provides a location for temporary memory to cater for
incessant frequent callers within a specified period. It gives them a higher priority over a new entrant call. This
algorithm should be implemented at every base station. The advantages of this algorithm are:
• It gave a priority to highly essential duties calls that needed immediate attention. This will thereby forestall any
casualties that may occur if such attention is not given.
• It gave priority to the most denied calls to grab the channel when they appear within a specified time.
• It does not allow any call to occupy the channel more than necessary when they are calls waiting to grab the
channel.
• It does not preempt the subscriber if there is no call waiting unlike the block-time that will preempt even if
there is no call waiting
• It allows dynamic allocation of channel when there is equal priority calls.
It allows dynamic allocation of channel when there is equal priority calls. RECOMMENDED ALGORITHMS:
1. START
2. DO WHILE SERVICE = TRUE
3. SET ESSENTIAL_CODES
4. SET K = 1// INITIALISING THE TIMESLOT
5. DO WHILE NOT FREE AND K<=8//TESTING FOR FREE TIMESLOT
6. K = K+1
7. LOOP
8. IF TIMESLOT <> FREE AND CALL = ESSENTIAL CALL THEN
9. DROP CALL WITH LEAST PRIORITY
10. LOAD THE ESSENTIAL CALL TO TIMESLOT (TK )
11. WHILE SERVICE_TIME> 0
12. CONTINUE THE CALL
13. WEND
14. ELSE
15. IF TIMESLOT = FREE AND CALL = ESSENTIAL CALL THEN
16. LOAD THE CALL TO TIMESLOT (TK )
17. WHILE SERVICE_TIME > 0
18. CONTINUE THE CALL
19. WEND
20. ELSE
21. IF TIMESLOT = FREE THEN
22. LOAD THE CALL WITH THE HIGHEST NUMBER OF PRESENCE
23. WHILE SERVICE_TIME< MAX_TIME AND NO WAIT SIGNAL OR SERVICE_TIME<AIR_TIME
24. CONTINUE THE CALL
25. WEND
26. ELSE
27. REJECT THE CALL
28. REGISTER AT THE TEMPORARY MEMORY
29. END IF
30. END IF
31. END IF
32. FETCH THE NEXT CALL
33. LOOP
The above network management models if used will enhance the network retainability, Network accessibility
and will bring a reduction in network congestion and block call rate.
IV. DATA PRESENTATION AND ANALYSIS
4.1 DATA AND VARIABLE PRESENTATION
In this work, variables such as allotted time of calls, number of chosen finite subscribers, probabilities of call
blocking, and offered traffic in erlang were used in the simulation processes in conjunction with their
respective values as generated from Erlang B formula.
Here, high number of subscribers were chosen based on the fact that network congestion mainly occurs when
there is a huge number of subscribers or customers trying to have access to the network simultaneously,
probably in the availability of limited channels.
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4.2TABLES SHOWING SIMULATION PARAMETERS
Table 4.1: Showing parameters for simulation one
Allotted time
for call(s)
No of finite
subscribers
chosen (N)
Probability of call
blocking (Pbl)
Timeslot chosen (n) Offered
traffic in
erlang (ℓ)
60 (sec) 200 0.0136 8 3.3333
60 (sec) 250 0.0359 8 4.1667
60 (sec) 280 0.0551 8 4.6667
Table 4.2: Showing parameters for simulation two
Allotted time
for call(s)
No of finite
subscribers
chosen (N)
Probability of call
blocking (Pbl)
Timeslot chosen (n) Offered
traffic in
erlang (ℓ)
120 (sec) 200 0.1597 8 6.6666
120 (sec) 250 0.2539 8 8.3333
120 (sec) 280 0.3061 8 9.3333
Table 4.3: Showing parameters for simulation three
Allotted time
for call(s)
No of finite
subscribers
chosen (N)
Probability of call
blocking (Pbl)
Timeslot chosen (n) Offered
traffic in
erlang (ℓ)
180 (sec) 200 0.3383 8 10.0000
180 (sec) 250 0.4410 8 12.5000
180 (sec) 280 0.4905 8 14.000
Table 4.4: Showing parameters for simulation four
Allotted time
for call(s)
No of finite
subscribers
chosen (N)
Probability of call
blocking (Pbl)
Timeslot chosen (n) Offered
traffic in
erlang (ℓ)
60 (sec) 200 3.9902e-007 16 3.3333
60 (sec) 250 6.2837e-006 16 4.1667
60 (sec) 280 2.3898e-005 16 4.6667
Table 4.5: Showing parameters for simulation five
Allotted time
for call(s)
No of finite
subscribers
chosen (N)
Probability of call
blocking (Pbl)
Timeslot chosen (n) Offered
traffic in
erlang (ℓ)
120 (sec) 200 0.0012 16 6.6666
120 (sec) 250 0.0114 16 8.3333
120 (sec) 280 0.0340 16 9.3333
Table 4.6: Showing parameters for simulation six
Allotted time
for call(s)
No of finite
subscribers
chosen (N)
Probability of call
blocking (Pbl)
Timeslot chosen (n) Offered
traffic in
erlang (ℓ)
180 (sec) 200 0.0652 16 10.0000
180 (sec) 250 0.5066 16 12.5000
180 (sec) 280 1.3949 16 14.000
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4.0 FIGURES SHOWING THE SIMULATION RESULTS.
Figure 4.1 a&b: showing the result for simulation one
(a)
(b)
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Figure 4.2 a&b: showing the result for simulation two
(a)
(b)
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Figure 4.3 a&b: showing the result for simulation three
(a)
(b)
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Figure 4.4 a&b: showing the result for simulation four
(a)
(b)
Figure 4.5 a&b: showing the result for simulation five
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(a)
(b)
Figure 4.6 a&b: showing the result for simulation six
(a)
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(b)
4.4 DISCUSSION AND FINDINGS BASED ON THE SIMULATIONS
The result of the simulation one indicates that 1% of the 200 subscribers will be denied access, 4% of 250
subscribers will be denied access and 6% of 280 subscribers will be denied access under the same condition of
60seconds maximum time.
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The Erlang B performs excellently with the number of calls during the busiest hour, but here, we are dealing
with following:
Finite numbers of subscribers that are potential callers and net highest number of subscribers that are
potential callers and not the highest number of subscribers that call during a particular hour. Every call is given
equal time sharing.
At any point in time, not more than 10% of the subscribers will be ready to call at any point in time.
Out of those that are ready to call, not more than 40% will be ready to spend more than 1 minute
considering the traffic of GSM services in Nigeria.
We can see that congestion and call block be minimized with this type of model.
The operators should consider the cost of equipment, installation, maintenance, profit returns and the location of
the base station when choosing any of the above loading case studies.
Taking all factors into consideration, I suggest the case study or simulation study one for the operators. The
reason for the choice is that for example, for every 250 calls, only ten calls will be denied as against the other
situation.
So with the first (simulation ones) case, there will be minimal congestion and a good profit returns.
Also, it is clearly from the simulation results of four to six, the chances of occurrence of call block is drastically
reduced as a result of increased timeslot which depicted the availability of more channels, and also recorded a
notable high probability of occurrence at every peak value of callers or subscribers using the same number of
timeslot.
It is almost impossible to prevent network congestion due to some unexpected events, such as accidents and
adverse.
Also from the simulation result of two and three, it is obvious that the probability of blocked calls increase
drastically with respect to the offered traffic in erlang as a result of increase in the time allotted to the
subscribers which shows that a minimal time show be allocated to subscribers to minimized the chances of
blocked call occurrences unless the congestion control algorithm is being used to accommodate as many
subscribers as possible using the priority time sharing, block time sharing, dynamic allocation without time
slicing and or hybrid congestion technique.
If simulations two and three are be chosen, the gain of the operator might be reduced as a result of lost calls and
more number of subscribers will be denied access.
It is almost impossible to prevent network congestion due to some unexpected events, such as accident and
adverse weather conditions.
V. CONCLUSION, CONTRIBUTION AND RECOMMENDATION
5.1 CONCLUSION
Network performance is the most important parameter for measurement of quality of service. Poor performance
of a telecom network would induce customer complaints and faults, thereby leading to customer dissatisfaction
towards the operator. It is evident from this presentation that the quality of service rendered by these operators is
far below expectation. So, urgent and proactive actors should be taken by the operators towards improving
network performance. If this is done, customer could enjoy the best quality of service in terms of call success
rate, voice quality, etc.
Customer satisfaction is critical to gain sustainable competitive edge in the GSM Market. In communication
networks, as the customer satisfaction on the services is directing dependent on the quality and the performance
of the network performance and Quality of Service (Qos) assessment are crucial. Also, from the research
conducted by NCC and others in quest for ameliorating the call block problem, it was noted that from the
average number of subscribers that dialed up to three or more times before getting connected, 58% of call
blocking rate was recorded which after using more number of timeslots (which depicted more available
channels) in this work was reduced to 28%, as showed in the simulation results and will also be reduced the
more using the developed congestion control algorithm technique.
For this purpose, network operators should survey performance of their networks and measure quality
parameters on a regular basis as customers meets and satisfaction are presumably to be the main market drive
especially wide are service network such as cellular communications network.
As network optimatization engineers spend efforts to increase quality and capacity of operational networks, and
to develop and deploy new services in order to meet custom demands and also guarantee customer satisfaction
key performance indicators (KPIs) are to be kept within some specified threshold values in order to provide the
Qos criteria required by both competent authorities and customers, since they are universally accepted
parameters of cellular networks.
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5.2 CONTRIBUTION
This research and study provides the following contributions:
1. Customer satisfaction and/or needs are integrated into benchmarking process and so, the quality of
service assessment in order to see how customers perceive quality of service.
2. Acknowledgement of the fact that some unexpected events such as accidents and adverse weather
condition can cause network congestion.
3. Introduces the use of algorithm in controlling network congestion
5.3 RECOMMENDATION
With these findings, it can be concluded that the Qos and overall performance of the GSM operation in Nigeria
is poor, unreliable and unsatisfied. It is an indication that Nigerians are yet to really enjoy the impact of GSM as
a new effective means of telecommunication.
In order to correct this ugly situation in the country and other countries with similar situation, suggestions on
how to improve the Qos of the GSM operation in the country need to be made. It is on this basis that the
following recommendations are made in order to ameliorate the observed defects:
1. The GSM operators in the country should focus more in building more BTS in order to increase their
network coverage rather than the current competitions or bonanzas they are doing in order to win more
customers.
2. NCC will be advised to inspect the GSM networks in the country regularly. This will aid the GSM
operators in improving their networks base to meet their ever increasing subscriber’s base. By this, the network
accessibility in the country will improve while high congested networks currently experience shall be reduced.
3. Network operators should build additional switching centers across the country and increase capacity to
handle traffic.
4. If a particular base station is to be taken “off line” (either for schedule maintenance, repairs, upgrades
etc),all neighboring base station should have their communication level increased. This will increase their
coverage area, thereby reducing congestion and dropped calls.
5. Operators should invest heavily in transmission network development and have a proper radio
planning. This would ensure increased network resilience, improved bandwidth utilization and alleviation of
capacity bottleneck.
It is believed that if the above recommendations are adhered to, the Qos and the overall performance of the
GSM operation in the country shall definitely improve. Also, it will indeed improve the communication systems
of the country as well as increasing revenue of the government, the citizenries and the operators.
REFERENCES
[1.] Adegove and Balogun (2008), performance Evaluation of GSM Mobile System in Nigeria.
[2.] Angus,(2001). Introduction to Erlang B & C, Tele Management Magazine.
[3.] Ajiboye and Wojuola, (2007). Stakeholders’ Perceptions of the Impact of GSM on Nigeria Rural
Economy.
[4.] Boulmalf,(2003), Performance Evaluation of Operational GSM Air- Inerface
[5.] Balogu (2008), Performance Evaluation of GSM Mobile System Nigeria.
[6.] Cusine, (1997), Changing and Billing Models for GSM future mobile internet.
[7.] Doyle, (2003). The design and implementation of the GSM auction in Nigeria.
[8.] Free Encyclopedia GSM frequency ranges: Encyclopedia, Retrieval on August 4,2009, from http:// en.
Alledpents.com/e/g/ga/gsm_ frequency_ ranges. Htm.
[9.] Goldsmith (2005). Wireless communications. CambridgeUniversity Press.
[10.] Konstain(2003), Radio Resources Management Schemes for GSM.
[11.] Kollar (2008). Evaluation of Real call setup success Rates in GSM.
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[12.] Kuboye, (2009), The Pathway of GSM to 3G systems in Nigeria.
[13.] Kuboye, (2010),Optimizatyion models for minimizing congestion in Global system for mobile
communication (GSM) in Nigeria.
[14.] Kuboye, (2006), Development of a framework for managing of congestion in GSM in Nigeria.
[15.] Kuboye and Fajuyibe (2009). Congestion Analysis on the Nigeria Global System. For Mobile
Communications (GSM) Network.
[16.] Mehota (1997), GSM System Engineering.
[17.] McGraw-Hill (1999), GSM superphones.
[18.] Nigerian Communication Commission (NCC) (2005). A Report on Network Quality of service and
performance of the GSM Networks in Nigerian.
[19.] NOKIA (2002). Introduction to GSM Training Document.
[20.] Ryscard, (1986) Introduction to congestion theory in Telephone systems.
[21.] Rahnema, (1993). Overview of the GSM system and protocol Architecture.
[22.] Salim, (2008), Performance Enhancements of GSM Celluar Phone Network using Dynamic Frequency
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[23.] Salaman, (2006),Performance and Analysis of a Time-Threshold Based Bandwidth.
[24.] Wiley (1975), Queuing System Theory, Volumes.
[25.] www. On-q.telecom.com
[26.] www. Tech republic. Com
[27.] www. Mobioleafrica.net
APPENDIX
clc
fprintf('Improving quality of service in GSM by reducing probability of call blocking through networknn')
fprintf(' dimensioning using Erlang b model and congestion control algorithmn')
fprintf(' Presented by: Ahuchaogu Nnamdi nnn');
rmx =460;
ct =input ('Press Enter key to Continue ');
m=60
n=8
nlines=200
l= (nlines * m)/3600
l1=l
sum = 0;
for i=0:8
sum = sum +( l^i/factorial(i))
end
pbl = ((l^n)/factorial(n)) / sum
nlines=250
l= (nlines * m)/3600
l2=l
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Manuscript id. 778715524 www.ijstre.com Page 27
sum = 0;
for i=0:8
sum = sum +( l^i/factorial(i))
end
pbl2 = ((l^n)/factorial(n)) / sum
nlines=280
l= (nlines * m)/3600
l3=l
sum = 0;
for i=0:8
sum = sum +( l^i/factorial(i))
end
pbl3 = ((l^n)/factorial(n)) / sum
bx =[l1 l2 l3];
by=[pbl, pbl2, pbl3];
figure(1)
bar(bx, by, 0.2)
title 'Evlang Traffic Model'
ylabel('Probability of Blocking')
xlabel('No of Subscribers per channel')
figure(2)
plot(bx,by,'xr')
hold on
grid on
title 'Evlang Traffic Model'
ylabel('Probability of Blocking')
xlabel('No of Subscribers per channel')
plot(bx,by,'-b')
FOR SIMULATION ONE:
m = 60
n =8
nlines =200
l =3.3333
l1 =3.3333
Sum =1
Sum = 4.3333
Sum = 9.8889
Sum =16.0617
Sum =21.2058
Sum =24.6351
Sum =26.5403
Sum =27.4476
Sum = 27.8256
pbl = 0.0136
nlines =250
l =4.1667
l2 =4.1667
Sum =1
28. Improving Quality of Service In GSM By Reducing Probability of Call Blocking Through Network.
Manuscript id. 778715524 www.ijstre.com Page 28
Sum =5.1667
Sum =13.8472
Sum = 25.9035
Sum =38.4622
Sum =48.9278
Sum = 56.1955
sum = 60.5216
sum = 62.7747
pbl2 =0.0359
nlines =280
l = 4.6667
l3 = 4.6667
Sum = 1
Sum =5.6667
Sum = 16.5556
Sum =33.4938
Sum =53.2551
Sum = 71.6990
Sum =86.0443
Sum =95.6078
Sum =101.1865
pbl3 = 0.0551
FOR SIMULATION TWO:
m =120
n = 8
nlines = 200
l =6.6667
l1 =6.666
sum =1
sum = 7.6667
sum = 29.8889
sum = 79.2716
sum = 161.5761
sum =271.3155
sum =393.2481
sum =509.3744
sum = 606.1464
pbl =0.1597
nlines = 250
l = 8.3333
l2 =8.3333
sum =1
sum =9.3333
sum = 44.0556
sum = 140.5062
sum =341.4450
sum =676.3429
sum =1.1415e+003
sum = 1.6952e+003
sum =2.2720e+003
pbl2 =0.2539
nlines =280
l =9.3333
29. Improving Quality of Service In GSM By Reducing Probability of Call Blocking Through Network.
Manuscript id. 778715524 www.ijstre.com Page 29
l3 =9.3333
sum =1
sum =10.3333
sum =53.8889
sum = 189.3951
sum =505.5761
sum =1.0958e+003
sum =2.0139e+003
sum =3.2380e+003
sum = 4.6662e+003
pbl3 =0.3061
FOR SIMULATION THREE:
m = 180
n = 8
nlines =200
l =10
l1 =10
sum =1
sum =11
sum =61
sum = 227.6667
sum =644.3333
sum =1.4777e+003
sum =2.8666e+003
sum =4.8507e+003
sum =7.3308e+003
pbl =0.3383
nlines =250
l =12.5000
l2 =12.5000
sum =1
sum =13.5000
sum =91.6250
sum =417.1458
sum = 1.4344e+003
sum =3.9775e+003
sum =9.2757e+003
sum = 1.8737e+004
sum = 3.3520e+004
pbl2 =0.4410
nlines =280
l = 14
l3 = 14
sum =1
sum =15
sum =113
sum =570.3333
sum =2171
sum =6.6529e+003
sum =1.7111e+004
sum = 3.8026e+004
sum = 7.4628e+004
pbl3 =0.4905
FOR SIMULATION FOUR
m = 60
30. Improving Quality of Service In GSM By Reducing Probability of Call Blocking Through Network.
Manuscript id. 778715524 www.ijstre.com Page 30
n =16
nlines =200
l =3.3333
l1 = 3.3333
sum = 1
sum = 4.3333
sum = 9.8889
sum = 16.0617
sum = 21.2058
sum =24.6351
sum = 26.5403
sum = 27.4476
sum = 27.8256
pbl = 3.9902e-007
nlines = 250
l = 4.1667
l2 = 4.1667
sum =1
sum = 5.1667
sum = 13.8472
sum = 25.9035
sum = 38.4622
sum = 48.9278
sum = 56.1955
sum = 60.5216
sum = 62.7747
pbl2 = 6.2837e-006
nlines = 280
l =4.6667
l3 = 4.6667
sum = 1
sum = 5.6667
sum = 16.5556
sum = 33.4938
sum = 53.2551
sum = 71.6990
sum = 86.0443
sum = 95.6078
sum = 101.1865
pbl3 = 2.3898e-005
FOR SIMULATION FIVE
m = 120
n =16
nlines = 200
l = 6.6667
l1 = 6.6667
sum =1
sum = 7.6667
sum = 29.8889
sum = 79.2716
sum = 161.5761
sum = 271.3155
sum = 393.248
sum = 509.3744
sum = 606.1464
31. Improving Quality of Service In GSM By Reducing Probability of Call Blocking Through Network.
Manuscript id. 778715524 www.ijstre.com Page 31
pbl = 0.0012
nlines = 250
l = 8.3333
l2 = 8.3333
sum = 1
sum = 9.3333
sum = 44.0556
sum = 140.5062
sum = 341.4450
sum = 676.3429
sum = 1.1415e+003
sum = 1.6952e+003
sum = 2.2720e+003
pbl2 = 0.0114
nlines = 280
l = 9.3333
l3 = 9.3333
sum = 1
sum = 10.3333
sum = 53.8889
sum = 189.3951
sum = 505.5761
sum = 1.0958e+003
sum = 2.0139e+003
sum = 3.2380e+003
sum = 4.6662e+003
pbl3 = 0.0340
FOR SIMULATION SIX
m = 180
n = 16
nlines = 200
l = 10
l1 = 10
sum = 1
sum = 11
sum = 61
sum = 227.6667
sum = 644.3333
sum =1.4777e+003
sum = 2.8666e+003
sum = 4.8507e+003
sum =7.3308e+003
pbl = 0.0652
nlines = 250
l = 12.5000
l2 = 12.5000
sum = 1
sum = 13.5000
sum = 91.6250
sum = 417.1458
sum = 1.4344e+003
sum = 3.9775e+003
sum = 9.2757e+003
32. Improving Quality of Service In GSM By Reducing Probability of Call Blocking Through Network.
Manuscript id. 778715524 www.ijstre.com Page 32
sum = 1.8737e+004
sum = 3.3520e+004
pbl2 = 0.5066
nlines = 280
l = 14
l3 = 14
sum = 1
sum = 15
sum = 113
sum = 570.3333
sum = 2171
sum = 6.6529e+003
sum = 1.7111e+004
sum = 3.8026e+004
sum =7.4628e+004
pbl3 = 1.3949