A simulation model is presented to analyze and evaluate the performance of VoIP based integrated
wireless LAN/WAN with taking into account various voice encoding schemes. The network model was
simulated using OPNET Modeler software. Different parameters that indicate the QoS like MOS, jitter,
end to end delay, traffic send and traffic received are calculated and analyzed in Wireless LAN/WAN
scenarios. Depending on this evaluation, Selection codecs G.729A consider the best choice for VoIP.
Due to the proliferation in the number of users that are accessing the internet and due to the increase in
the number of the electronic devices that support mobility like mobiles, laptops and many others that
definitely lead to the need of a protocol that supports a mobility. Mobile Internet Protocol is a
recommended Internet protocol designed to support the mobility of a user (host). This protocol provides a
continuous connectivity for any mobile host . In the traditional Mobile IP all packets forwarded to the
Mobile host from the correspondent node will be forwarded via the Home Agent (HA) and that leads to
the triangle routing problem .
(ISP MBG) technique is used as a route optimization technique for solving the triangle routing problem
in conventional Mobile IPv4. This technique has been implemented on .net platform .The study of this
technique was discussed before using 2 similar Internet Service Providers and the simulation results
provided a better performance compared with the Conventional Mobile IP Technique. In this paper the
simulator will be used to study the performance of the (ISP MBG) technique using two different Internet
Service Providers ( ISPs) structures separated by a single Mobile Border Gateway ( MBG).Simulation
results shows also a better performance compared with the conventional Mobile IP technique .
1) The document discusses route optimization techniques for solving the triangle routing problem in Mobile IPv4, specifically evaluating the performance of the Internet Service Provider Mobile Border Gateway (ISP MBG) scheme.
2) It provides background on Mobile IP, the triangle routing problem, and introduces the ISP MBG technique for optimizing routes.
3) The study evaluates the performance of ISP MBG by varying system parameters like number of nodes and zones, finding it provides shorter transmission times compared to conventional Mobile IP.
Analysis of VoIP Traffic in WiMAX EnvironmentEditor IJMTER
This document reviews several studies that analyzed the performance of VoIP traffic over WiMAX networks using different VoIP codecs and WiMAX service classes. It summarizes the findings of various papers on how QoS parameters like throughput, delay, jitter compared for codecs like G.711, G.723, G.729 when using the UGS, rtPS, nrtPS and BE service classes. Most studies found that UGS generally performed best for VoIP due to its ability to guarantee bandwidth and minimize jitter and delay, while G.711 typically provided the best voice quality. The document aims to compare the results across different service classes and codecs.
This document discusses speed adaptive mobile IP over wireless LAN. It first analyzes the relationship between performance and moving speed for mobile IP over wireless LAN, showing that current mobile IP is not suitable for rapid movement. It then proposes a speed adaptive mobile IP protocol that extends registration messages with speed information to allow the network behavior to automatically adapt based on node speed, improving performance for rapid movement without high resource costs. The protocol is emulated and shown to greatly improve mobile IP performance for rapid movement over wireless LAN.
This document provides an overview of Chapter 7 from the textbook "Computer Networking: A Top-Down Approach 8th edition" by Jim Kurose and Keith Ross. It includes notes on using the PowerPoint slides freely but asking users to cite the source and copyright. The chapter outline covers wireless links and networks, WiFi (802.11), cellular networks, and mobility management. It provides context on the growth of wireless and mobile networks and examples of wireless link characteristics, protocols, and WiFi frame addressing.
PLNOG 6: Maciej Konstantynowicz - Implementing Seamless MPLS PROIDEA
Implementing Seamless MPLS discusses service provider priorities such as reducing costs, simplifying operations, and improving service delivery. It outlines requirements for a converged packet network including support for large scale, deterministic availability, and simplified service provisioning. The document also describes Juniper's Seamless MPLS architecture which addresses these requirements through hierarchical MPLS labeling, fast restoration mechanisms, and decoupled network and service architectures.
The document describes a software project called MASK that aims to develop a web-based application for LTE planning processes like calculating site requirements and throughput for a given area, placing sites on a map, following LTE planning standards and providing skills relevant to mobile communications careers. The project methodology involves studying LTE features and planning, choosing tools like C# and ArcGIS, implementing algorithms, and creating a graphical user interface for the program.
Performance Analysis of Data Traffic Offload Scheme on Long Term Evolution (L...TELKOMNIKA JOURNAL
One of new mobile technology is being developed by 3GPP is Long Term Evolution (LTE). LTE
usually used by user because provide high data rate. Many traffic sending over LTE, makes several users
didn’t get good Quality of Service (QoS). Traffic diversion is needed to increasing QoS value. It can be
done with offloading data method from LTE to Wi-Fi network. This paper using 802.11ah standard to
evaluate Wi-Fi network. IEEE 802.11ah have 1000 meters coverage area and efficiency energy
mechanism, which is proposed for M2M in 5G techonology. Some research has proven that traffic
diversion with offloading can increasing network performance. The contribution of this paper is to evaluate
the impact of traffic offload between LTE and IEEE 802.11ah standard. This paper propose two scenarios
using increment number of user and increment mobility speed of user to evaluate throughput and delay
value before and after the offload process. The simulation will simulate using Network Simulator-3. We can
conclude that network performance after offloading is better for every scenario. For increment number of
user scenario, throughput value increasing 29.08%, and delay decreasing 8.12%. Scenario with increment
mobility speed of user obtain throughput value increasing 37,57%, and delay value decreasing 27.228%.
Due to the proliferation in the number of users that are accessing the internet and due to the increase in
the number of the electronic devices that support mobility like mobiles, laptops and many others that
definitely lead to the need of a protocol that supports a mobility. Mobile Internet Protocol is a
recommended Internet protocol designed to support the mobility of a user (host). This protocol provides a
continuous connectivity for any mobile host . In the traditional Mobile IP all packets forwarded to the
Mobile host from the correspondent node will be forwarded via the Home Agent (HA) and that leads to
the triangle routing problem .
(ISP MBG) technique is used as a route optimization technique for solving the triangle routing problem
in conventional Mobile IPv4. This technique has been implemented on .net platform .The study of this
technique was discussed before using 2 similar Internet Service Providers and the simulation results
provided a better performance compared with the Conventional Mobile IP Technique. In this paper the
simulator will be used to study the performance of the (ISP MBG) technique using two different Internet
Service Providers ( ISPs) structures separated by a single Mobile Border Gateway ( MBG).Simulation
results shows also a better performance compared with the conventional Mobile IP technique .
1) The document discusses route optimization techniques for solving the triangle routing problem in Mobile IPv4, specifically evaluating the performance of the Internet Service Provider Mobile Border Gateway (ISP MBG) scheme.
2) It provides background on Mobile IP, the triangle routing problem, and introduces the ISP MBG technique for optimizing routes.
3) The study evaluates the performance of ISP MBG by varying system parameters like number of nodes and zones, finding it provides shorter transmission times compared to conventional Mobile IP.
Analysis of VoIP Traffic in WiMAX EnvironmentEditor IJMTER
This document reviews several studies that analyzed the performance of VoIP traffic over WiMAX networks using different VoIP codecs and WiMAX service classes. It summarizes the findings of various papers on how QoS parameters like throughput, delay, jitter compared for codecs like G.711, G.723, G.729 when using the UGS, rtPS, nrtPS and BE service classes. Most studies found that UGS generally performed best for VoIP due to its ability to guarantee bandwidth and minimize jitter and delay, while G.711 typically provided the best voice quality. The document aims to compare the results across different service classes and codecs.
This document discusses speed adaptive mobile IP over wireless LAN. It first analyzes the relationship between performance and moving speed for mobile IP over wireless LAN, showing that current mobile IP is not suitable for rapid movement. It then proposes a speed adaptive mobile IP protocol that extends registration messages with speed information to allow the network behavior to automatically adapt based on node speed, improving performance for rapid movement without high resource costs. The protocol is emulated and shown to greatly improve mobile IP performance for rapid movement over wireless LAN.
This document provides an overview of Chapter 7 from the textbook "Computer Networking: A Top-Down Approach 8th edition" by Jim Kurose and Keith Ross. It includes notes on using the PowerPoint slides freely but asking users to cite the source and copyright. The chapter outline covers wireless links and networks, WiFi (802.11), cellular networks, and mobility management. It provides context on the growth of wireless and mobile networks and examples of wireless link characteristics, protocols, and WiFi frame addressing.
PLNOG 6: Maciej Konstantynowicz - Implementing Seamless MPLS PROIDEA
Implementing Seamless MPLS discusses service provider priorities such as reducing costs, simplifying operations, and improving service delivery. It outlines requirements for a converged packet network including support for large scale, deterministic availability, and simplified service provisioning. The document also describes Juniper's Seamless MPLS architecture which addresses these requirements through hierarchical MPLS labeling, fast restoration mechanisms, and decoupled network and service architectures.
The document describes a software project called MASK that aims to develop a web-based application for LTE planning processes like calculating site requirements and throughput for a given area, placing sites on a map, following LTE planning standards and providing skills relevant to mobile communications careers. The project methodology involves studying LTE features and planning, choosing tools like C# and ArcGIS, implementing algorithms, and creating a graphical user interface for the program.
Performance Analysis of Data Traffic Offload Scheme on Long Term Evolution (L...TELKOMNIKA JOURNAL
One of new mobile technology is being developed by 3GPP is Long Term Evolution (LTE). LTE
usually used by user because provide high data rate. Many traffic sending over LTE, makes several users
didn’t get good Quality of Service (QoS). Traffic diversion is needed to increasing QoS value. It can be
done with offloading data method from LTE to Wi-Fi network. This paper using 802.11ah standard to
evaluate Wi-Fi network. IEEE 802.11ah have 1000 meters coverage area and efficiency energy
mechanism, which is proposed for M2M in 5G techonology. Some research has proven that traffic
diversion with offloading can increasing network performance. The contribution of this paper is to evaluate
the impact of traffic offload between LTE and IEEE 802.11ah standard. This paper propose two scenarios
using increment number of user and increment mobility speed of user to evaluate throughput and delay
value before and after the offload process. The simulation will simulate using Network Simulator-3. We can
conclude that network performance after offloading is better for every scenario. For increment number of
user scenario, throughput value increasing 29.08%, and delay decreasing 8.12%. Scenario with increment
mobility speed of user obtain throughput value increasing 37,57%, and delay value decreasing 27.228%.
This document presents a novel approach for minimizing delay and load in wireless networks (WiMAX) developed by Shilpa Mehta et al. It begins by introducing WiMAX and discussing challenges in providing quality of service. It then proposes a new scheduling algorithm called QOS Recovered that aims to minimize delay and load by fixing queue size and number of packets. The algorithm is compared to the existing weighted fair queuing algorithm through simulation. The document provides background on scheduling in WiMAX and discusses common scheduling strategies and algorithms. It also describes using the OPNET simulator to model the wireless network and evaluate the new algorithm's performance.
1. The document discusses how Multi-Protocol Label Switching (MPLS) can improve Voice over Internet Protocol (VoIP) services by enabling traffic engineering and quality of service controls.
2. MPLS allows traffic to be forwarded at layer 2 for faster routing and makes it easier to manage networks for quality of service. This helps meet the low latency and jitter requirements of real-time VoIP traffic.
3. The document analyzes VoIP performance over an MPLS network connecting three branch offices using a network monitoring tool. It finds that while MPLS provides better connectivity than the public Internet, additional steps may be needed to deliver business-quality VoIP.
This document provides an overview of fixed access networks and the service order project flow. It discusses key topics such as:
- The hierarchy of ISPs from tier 1 to tier 3 and their roles in connectivity.
- The main types of fixed access network services including dedicated internet access, leased lines, VPNs, and PRI.
- Factors considered in network planning like topology, technology, and last mile solutions.
- The end-to-end process flow for a service order project from initial order to provisioning and acceptance.
- An example project for a dedicated internet access order for 155 Mbps of bandwidth for a customer.
ANALYTICAL PERFORMANCE EVALUATION OF AN LDPC CODED INDOOR OPTICAL WIRELESS CO...optljjournal
Recently, indoor Optical Wireless (OW) connectivity has gained significant attention as a possible
alternative to tackle the problem of bottleneck access and as an improvement to ever more conventional RF
/ microwave connections. In indoor OW communication, OOK encoding is more widely used owing to its
effective usage of bandwidth and robustness to timing errors, given the fact that the power consumption is
less than PPM. The modulation format in this research work is Q-array PPM over lasers, with modulation
of power. The effects of the analysis are analyzed numerically in view of the amount of bit error (BER). It is
shown that, because of coding for 4PPM framework, the bit error performance is increased. For instance,
an LDPC-coded device with stable foundation radiation provides a important coding improvement of 5 to 6
dB over uncoded device at BER in the order of 10-8 and 10-12 respectively.
This document discusses PowerGrid's diversification into the telecom business under the brand PowerTel. It provides an overview of PowerGrid as the central transmission utility of India, carrying over 51% of the country's power. In 2001, PowerGrid diversified into telecom to utilize spare optic fiber capacity from its transmission infrastructure, providing telecom services across India. The document describes PowerTel's network and various telecom equipment used, and also discusses digital transmission systems like SDH and DWDM, fiber management, and troubleshooting techniques.
This document outlines the basic design of a Tier 3 ISP network. It defines key ISP terminology like tiers and points of presence. The project goal is described as providing internet access to 3 departments on campus through a wired or wireless network. The core architecture includes a backbone with a core router connecting to distribution routers that provide access to the departments. The document also covers addressing, routing protocols and how the network would be set up and tested.
A Comparative Analysis of the Performance of VoIP Traffic with Different Type...ijcnac
The key QoS parameters for VoIP are delay, jitter and loss. In the Internet, VoIP requires
the underlying packet switched network to minimize the impact of these parameters. A
major contributing factor in this regard is traffic engineering carried out by scheduling
algorithms. This paper studies the behavior of different types of scheduling algorithms on
the delay, jitter and loss QoS parameters. The performance evaluation involves
identifying the scheduling algorithms which are most suitable for VoIP communications.
The result from the analysis also shows the impact of the QoS parameters on VoIP over
the Internet.
This document provides an introduction to mobile computing. It defines mobile computing as using a computer while on the move, involving mobility, computing, and network connectivity. The key aspects of mobile computing are discussed, including mobile communication infrastructure, software, hardware, and devices. Common network types that enable mobile computing like WLAN, MAN, WAN, and wireless networks are also summarized. The relationship between mobile computing and wireless networking is described, with wireless networking providing the basic communication capabilities. Examples of mobile computing applications are given for various fields.
4 lte access transport network dimensioning issue 1.02saeed_sh65
The document discusses several key aspects of an LTE access transport network:
1. It describes the five major interfaces of an eNodeB including S1, X2, OM, clock, and co-transmission interfaces.
2. It explains the protocols used on the S1 and X2 interfaces including SCTP, GTP-U, and X2AP.
3. It provides an overview of the different layers - layers 1, 2, and 3 - that can be used as transport bearer networks for an LTE system and their characteristics.
The document discusses how to characterize and dimension user traffic in 4G networks. It describes how to define data traffic in terms of data speed and data tonnage. Data speed is the rate at which data is transferred, while data tonnage refers to the total amount of data exchanged. The document provides examples of data speed metrics used in 3GPP standards and outlines factors to consider when calculating expected data usage per subscriber based on typical mobile application usage patterns and available data plans. Dimensioning user traffic accurately is important for designing 4G networks to meet capacity demands.
A review study of handover performance in mobile ipIJCNCJournal
The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet
Engineering Task Force (IETF) that addresses the mobility issues. In order to support un-interrupted
services and seamless mobility of nodes across the networks (and/or sub-networks) with permanent IP
addresses, handover is performed in mobile IP enabled networks. Handover in mobile IP is source cause of
performance degradation as it results in increased latency and packet loss during handover. Other issues
like scalability issues, ordered packet delivery issues, control plane management issues etc are also
adversely affected by it. The paper provides a constructive survey by classifying, discussing and comparing
different handover techniques that have been proposed so far, for enhancing the performance during
handovers. Finally some general solutions that have been used to solve handover related problems are
briefly discussed.
Performance Evaluation of two Port and four Port Measurement for Twisted Pair...IJECEIAES
This document summarizes a study that evaluated twisted pair cable measurement using two-port and four-port vector network analyzers. Twisted pair cables of 500m and 1000m in length with various conditions were measured. The four-port measurements were converted to two-port S-parameters for comparison. Results showed good correlation between methods at 500m, especially below 50MHz. Four-port measurement is suitable for measuring twisted pair cable up to higher frequencies but over shorter distances. Root mean square error analysis supported this, with lower errors below 5MHz. The study validated using a four-port analyzer for twisted pair cable characterization.
Implementation Cost Analysis of the Interpolator for the Wimax Technologyiosrjce
The design of the multirate filter (programmable) has been proposed which can be used in digital
transceivers that meets 802.16d/e (wimax) standard in the wireless communication system. Wimax is a
technology emerging in the wireless communication system in order to increase the broadband wireless internet
access. As there is wide spread need of the digital representation of the signal for the transmission and storage
which create the challenges in DSP [1]. In this paper, analysis of the implementation cost of interpolator for the
wimax technology, and cost of interpolator is analyzed on the basis of number of adders and multiplier. The
Filters are designed using the FDA (filters design and analysis) tool in MATLAB.
The document summarizes planning and optimization of an LTE radio access network for an urban area in Taiz City, Yemen. It involved using simulation software to plan the network, including determining the number and locations of base stations. The network was then optimized using techniques like Automatic Cell Planning and Automatic Frequency Planning. This improved coverage from 90% to 98%, CINR from 65% to 77%, and increased total network traffic by 30%. The optimization reduced overlapping between sectors and interference, and increased throughput and coverage area.
Wireless networks are accessible to anyone within the router’s transmission radius. This makes them vulnerable to attacks. Hotspots are available in public places such as airports, restaurants, parks, etc.
In this module, we will introduce you to common techniques used to exploit weaknesses in wireless network security implementations. We will also look at some of the countermeasures you can put in place to protect against such attacks.
AN EXPERIMENTAL STUDY OF IOT NETWORKS UNDER INTERNAL ROUTING ATTACKIJCNCJournal
Internet of Things (IoT) deployments mostly relies on the establishment of Low-Power and Lossy Networks (LLNs) among a large number of constraint devices. The Internet Engineering Task Force (IETF) provides an effective IPv6-based LLN routing protocol, namely the IPv6 Routing Protocol for Low Power and Lossy Network (RPL). RPL provides adequate protection against external security attacks but stays vulnerable to internal routing attacks such as a rank attack. Malicious RPL nodes can carry out a rank attack in different forms and cause serious network performance degradation. An experimental study of the impact of the decreased rank attack on the overall network performance is presented in this paper. In also besides, it is
important to understand the main influencing factors in this context. In this study, several some many network scenarios were considered with varying network sizes, attacker properties, and topological setups. The experimental results indicate a noticeable adverse effect of the rank attack on the average PDR, delay, ETX, and beacon interval. However, such impact was varied according to network size, attacker position,
attacker neighbor count, number of attack-affected nodes, and overall hops increase. The results give a practical reference to the overall performance of RPL networks under rank attacks.
Adhoc mobile wireless network enhancement based on cisco devicesIJCNCJournal
This document discusses enhancing the performance of ad hoc wireless networks using Cisco devices. It proposes using Cisco routers and access points to create a three-layer ad hoc network with endpoints, intermediate coordinators, and a core router layer for improved processing, reliability, cost, power consumption, and accessibility. It then outlines various protocols and configurations that could be implemented using Cisco devices, including NAT, ACLs, DHCP, and wireless security settings. Diagrams and tables show an example network topology and device IP addresses and configurations.
A review of security attacks and intrusion detection schemes in wireless sens...ijwmn
Wireless sensor networks are currently the greatest innovation in the field of telecommunications. WSNs
have a wide range of potential applications, including security and surveillance, control, actuation and
maintenance of complex systems and fine-grain monitoring of indoor and outdoor environments. However
security is one of the major aspects of Wireless sensor networks due to the resource limitations of sensor
nodes. Those networks are facing several threats that affect their functioning and their life. In this paper we
present security attacks in wireless sensor networks, and we focus on comparison and analysis of recent
Intrusion Detection schemes in WSNs.
Due to the rapidly increasing data speed requirement, it has become essential to smartly utilize the available frequency spectrum. In wireless communications systems, channel quality parameters are often used to enable resource allocation techniques that improve system capacity and user quality. The uncoded bit or symbol error rate (SER) is specified as an important parameter in the second and third generation partnership project (3GPP). Nonetheless, techniques to estimate the uncoded SER are usually not much published. This paper introduces a novel uncoded bit error rate (BER) estimation method using the
accurate-bits sequence of the new channel codes over the AWGN channel. Here, we have used the new channel codes as a forward error correction coding scheme for our communication system. This paper also presents the simulation results to demonstrate and compare the estimation accuracy of the proposed method over the AWGN channel.
Intelligent transportation system (ITS) is an application which provides intelligence to the transportation
and traffic management systems. Although the word ITS applies to all systems in the transportation but as
per the European union directive it is the application of Information and communication technology in the
field of transportation is defined as ITS. The communication technology has evolved greatly today from
2G/3G to long term evolution (LTE). In this paper we focus on the LTE and its application in the ITS. Since
LTE offers excellent QoS, wide area coverage and high availability it is a preferred choice for vehicle to
infrastructure (V2I) service. At the same time the LTE customer base is increasing day by day which results
in congestion and accessing the network to send or request resources becomes difficult. In this paper we
have proposed a group based node selection algorithm to reduce the preamble ID collision otherwise this
uncoordinated preamble ID transmission by vehicle node (VN) will eventually clog the network and there
will be a massive congestion and re-transmissions attempts by VNs to obtain the random access channel
(RACH).
A major role is played in the layout and evaluation of any empirical wireless structure to manifest is the goal of this paper that counterfeit mode architectures affect counterfeit conduct, regarding structure accomplishment metrics, essentially and therefore, the excellent architecture should be explored in order to accomplish the most accurate and reliable results. It is found that the most analytical factors it is found that that actuate counterfeit mode accomplishment are counterfeit time, structure event organizing and
grade of adequate. It is, also, found that counterfeit time in relation to event existence in the real structure
along with the usage of modern architectural concepts such as multi-interweave technology complement
analytical issues too in the advancement of an adequate counterfeit organization for wireless communications. In order to evaluate the above findings an extensive empirical review has been
demeanored analysising several distinct events counterfeitorganizations towards presenting the relation
between channel designing collections, counterfeit time and structure accomplishment.
Cellular wireless systems like GSM suffer from congestion resulting in overall system degradation and poor service delivery. When the traffic demand in a geographical area is high, the input traffic rate will exceed thecapacity of the output lines. This work focused on homogenous wireless network (the network traffic and resource dimensioning that are statistically identical) such that the network performance
evaluation can be reduced to a system with single cell and a single traffic type. Such system can employa queuing model to evaluate the performance metric of a cell in terms of blocking probability.
Five congestion control models were compared in the work to ascertain their peculiarities, they are Erlang B, Erlang C, Engset (cleared), Engset (buffered), and Bernoulli. To analyze the system, an aggregate onedimensional Markov chain wasderived, such that it describes a call arrival process under the assumption
that it is Poisson distributed. The models were simulated and their results show varying performances, however the Bernoulli model (Pb5) tends to show a situation that allows more users access to the system and the congestion level remain unaffected despite increase in the number of users and the offered traffic into the system.
This document presents a novel approach for minimizing delay and load in wireless networks (WiMAX) developed by Shilpa Mehta et al. It begins by introducing WiMAX and discussing challenges in providing quality of service. It then proposes a new scheduling algorithm called QOS Recovered that aims to minimize delay and load by fixing queue size and number of packets. The algorithm is compared to the existing weighted fair queuing algorithm through simulation. The document provides background on scheduling in WiMAX and discusses common scheduling strategies and algorithms. It also describes using the OPNET simulator to model the wireless network and evaluate the new algorithm's performance.
1. The document discusses how Multi-Protocol Label Switching (MPLS) can improve Voice over Internet Protocol (VoIP) services by enabling traffic engineering and quality of service controls.
2. MPLS allows traffic to be forwarded at layer 2 for faster routing and makes it easier to manage networks for quality of service. This helps meet the low latency and jitter requirements of real-time VoIP traffic.
3. The document analyzes VoIP performance over an MPLS network connecting three branch offices using a network monitoring tool. It finds that while MPLS provides better connectivity than the public Internet, additional steps may be needed to deliver business-quality VoIP.
This document provides an overview of fixed access networks and the service order project flow. It discusses key topics such as:
- The hierarchy of ISPs from tier 1 to tier 3 and their roles in connectivity.
- The main types of fixed access network services including dedicated internet access, leased lines, VPNs, and PRI.
- Factors considered in network planning like topology, technology, and last mile solutions.
- The end-to-end process flow for a service order project from initial order to provisioning and acceptance.
- An example project for a dedicated internet access order for 155 Mbps of bandwidth for a customer.
ANALYTICAL PERFORMANCE EVALUATION OF AN LDPC CODED INDOOR OPTICAL WIRELESS CO...optljjournal
Recently, indoor Optical Wireless (OW) connectivity has gained significant attention as a possible
alternative to tackle the problem of bottleneck access and as an improvement to ever more conventional RF
/ microwave connections. In indoor OW communication, OOK encoding is more widely used owing to its
effective usage of bandwidth and robustness to timing errors, given the fact that the power consumption is
less than PPM. The modulation format in this research work is Q-array PPM over lasers, with modulation
of power. The effects of the analysis are analyzed numerically in view of the amount of bit error (BER). It is
shown that, because of coding for 4PPM framework, the bit error performance is increased. For instance,
an LDPC-coded device with stable foundation radiation provides a important coding improvement of 5 to 6
dB over uncoded device at BER in the order of 10-8 and 10-12 respectively.
This document discusses PowerGrid's diversification into the telecom business under the brand PowerTel. It provides an overview of PowerGrid as the central transmission utility of India, carrying over 51% of the country's power. In 2001, PowerGrid diversified into telecom to utilize spare optic fiber capacity from its transmission infrastructure, providing telecom services across India. The document describes PowerTel's network and various telecom equipment used, and also discusses digital transmission systems like SDH and DWDM, fiber management, and troubleshooting techniques.
This document outlines the basic design of a Tier 3 ISP network. It defines key ISP terminology like tiers and points of presence. The project goal is described as providing internet access to 3 departments on campus through a wired or wireless network. The core architecture includes a backbone with a core router connecting to distribution routers that provide access to the departments. The document also covers addressing, routing protocols and how the network would be set up and tested.
A Comparative Analysis of the Performance of VoIP Traffic with Different Type...ijcnac
The key QoS parameters for VoIP are delay, jitter and loss. In the Internet, VoIP requires
the underlying packet switched network to minimize the impact of these parameters. A
major contributing factor in this regard is traffic engineering carried out by scheduling
algorithms. This paper studies the behavior of different types of scheduling algorithms on
the delay, jitter and loss QoS parameters. The performance evaluation involves
identifying the scheduling algorithms which are most suitable for VoIP communications.
The result from the analysis also shows the impact of the QoS parameters on VoIP over
the Internet.
This document provides an introduction to mobile computing. It defines mobile computing as using a computer while on the move, involving mobility, computing, and network connectivity. The key aspects of mobile computing are discussed, including mobile communication infrastructure, software, hardware, and devices. Common network types that enable mobile computing like WLAN, MAN, WAN, and wireless networks are also summarized. The relationship between mobile computing and wireless networking is described, with wireless networking providing the basic communication capabilities. Examples of mobile computing applications are given for various fields.
4 lte access transport network dimensioning issue 1.02saeed_sh65
The document discusses several key aspects of an LTE access transport network:
1. It describes the five major interfaces of an eNodeB including S1, X2, OM, clock, and co-transmission interfaces.
2. It explains the protocols used on the S1 and X2 interfaces including SCTP, GTP-U, and X2AP.
3. It provides an overview of the different layers - layers 1, 2, and 3 - that can be used as transport bearer networks for an LTE system and their characteristics.
The document discusses how to characterize and dimension user traffic in 4G networks. It describes how to define data traffic in terms of data speed and data tonnage. Data speed is the rate at which data is transferred, while data tonnage refers to the total amount of data exchanged. The document provides examples of data speed metrics used in 3GPP standards and outlines factors to consider when calculating expected data usage per subscriber based on typical mobile application usage patterns and available data plans. Dimensioning user traffic accurately is important for designing 4G networks to meet capacity demands.
A review study of handover performance in mobile ipIJCNCJournal
The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet
Engineering Task Force (IETF) that addresses the mobility issues. In order to support un-interrupted
services and seamless mobility of nodes across the networks (and/or sub-networks) with permanent IP
addresses, handover is performed in mobile IP enabled networks. Handover in mobile IP is source cause of
performance degradation as it results in increased latency and packet loss during handover. Other issues
like scalability issues, ordered packet delivery issues, control plane management issues etc are also
adversely affected by it. The paper provides a constructive survey by classifying, discussing and comparing
different handover techniques that have been proposed so far, for enhancing the performance during
handovers. Finally some general solutions that have been used to solve handover related problems are
briefly discussed.
Performance Evaluation of two Port and four Port Measurement for Twisted Pair...IJECEIAES
This document summarizes a study that evaluated twisted pair cable measurement using two-port and four-port vector network analyzers. Twisted pair cables of 500m and 1000m in length with various conditions were measured. The four-port measurements were converted to two-port S-parameters for comparison. Results showed good correlation between methods at 500m, especially below 50MHz. Four-port measurement is suitable for measuring twisted pair cable up to higher frequencies but over shorter distances. Root mean square error analysis supported this, with lower errors below 5MHz. The study validated using a four-port analyzer for twisted pair cable characterization.
Implementation Cost Analysis of the Interpolator for the Wimax Technologyiosrjce
The design of the multirate filter (programmable) has been proposed which can be used in digital
transceivers that meets 802.16d/e (wimax) standard in the wireless communication system. Wimax is a
technology emerging in the wireless communication system in order to increase the broadband wireless internet
access. As there is wide spread need of the digital representation of the signal for the transmission and storage
which create the challenges in DSP [1]. In this paper, analysis of the implementation cost of interpolator for the
wimax technology, and cost of interpolator is analyzed on the basis of number of adders and multiplier. The
Filters are designed using the FDA (filters design and analysis) tool in MATLAB.
The document summarizes planning and optimization of an LTE radio access network for an urban area in Taiz City, Yemen. It involved using simulation software to plan the network, including determining the number and locations of base stations. The network was then optimized using techniques like Automatic Cell Planning and Automatic Frequency Planning. This improved coverage from 90% to 98%, CINR from 65% to 77%, and increased total network traffic by 30%. The optimization reduced overlapping between sectors and interference, and increased throughput and coverage area.
Wireless networks are accessible to anyone within the router’s transmission radius. This makes them vulnerable to attacks. Hotspots are available in public places such as airports, restaurants, parks, etc.
In this module, we will introduce you to common techniques used to exploit weaknesses in wireless network security implementations. We will also look at some of the countermeasures you can put in place to protect against such attacks.
AN EXPERIMENTAL STUDY OF IOT NETWORKS UNDER INTERNAL ROUTING ATTACKIJCNCJournal
Internet of Things (IoT) deployments mostly relies on the establishment of Low-Power and Lossy Networks (LLNs) among a large number of constraint devices. The Internet Engineering Task Force (IETF) provides an effective IPv6-based LLN routing protocol, namely the IPv6 Routing Protocol for Low Power and Lossy Network (RPL). RPL provides adequate protection against external security attacks but stays vulnerable to internal routing attacks such as a rank attack. Malicious RPL nodes can carry out a rank attack in different forms and cause serious network performance degradation. An experimental study of the impact of the decreased rank attack on the overall network performance is presented in this paper. In also besides, it is
important to understand the main influencing factors in this context. In this study, several some many network scenarios were considered with varying network sizes, attacker properties, and topological setups. The experimental results indicate a noticeable adverse effect of the rank attack on the average PDR, delay, ETX, and beacon interval. However, such impact was varied according to network size, attacker position,
attacker neighbor count, number of attack-affected nodes, and overall hops increase. The results give a practical reference to the overall performance of RPL networks under rank attacks.
Adhoc mobile wireless network enhancement based on cisco devicesIJCNCJournal
This document discusses enhancing the performance of ad hoc wireless networks using Cisco devices. It proposes using Cisco routers and access points to create a three-layer ad hoc network with endpoints, intermediate coordinators, and a core router layer for improved processing, reliability, cost, power consumption, and accessibility. It then outlines various protocols and configurations that could be implemented using Cisco devices, including NAT, ACLs, DHCP, and wireless security settings. Diagrams and tables show an example network topology and device IP addresses and configurations.
A review of security attacks and intrusion detection schemes in wireless sens...ijwmn
Wireless sensor networks are currently the greatest innovation in the field of telecommunications. WSNs
have a wide range of potential applications, including security and surveillance, control, actuation and
maintenance of complex systems and fine-grain monitoring of indoor and outdoor environments. However
security is one of the major aspects of Wireless sensor networks due to the resource limitations of sensor
nodes. Those networks are facing several threats that affect their functioning and their life. In this paper we
present security attacks in wireless sensor networks, and we focus on comparison and analysis of recent
Intrusion Detection schemes in WSNs.
Due to the rapidly increasing data speed requirement, it has become essential to smartly utilize the available frequency spectrum. In wireless communications systems, channel quality parameters are often used to enable resource allocation techniques that improve system capacity and user quality. The uncoded bit or symbol error rate (SER) is specified as an important parameter in the second and third generation partnership project (3GPP). Nonetheless, techniques to estimate the uncoded SER are usually not much published. This paper introduces a novel uncoded bit error rate (BER) estimation method using the
accurate-bits sequence of the new channel codes over the AWGN channel. Here, we have used the new channel codes as a forward error correction coding scheme for our communication system. This paper also presents the simulation results to demonstrate and compare the estimation accuracy of the proposed method over the AWGN channel.
Intelligent transportation system (ITS) is an application which provides intelligence to the transportation
and traffic management systems. Although the word ITS applies to all systems in the transportation but as
per the European union directive it is the application of Information and communication technology in the
field of transportation is defined as ITS. The communication technology has evolved greatly today from
2G/3G to long term evolution (LTE). In this paper we focus on the LTE and its application in the ITS. Since
LTE offers excellent QoS, wide area coverage and high availability it is a preferred choice for vehicle to
infrastructure (V2I) service. At the same time the LTE customer base is increasing day by day which results
in congestion and accessing the network to send or request resources becomes difficult. In this paper we
have proposed a group based node selection algorithm to reduce the preamble ID collision otherwise this
uncoordinated preamble ID transmission by vehicle node (VN) will eventually clog the network and there
will be a massive congestion and re-transmissions attempts by VNs to obtain the random access channel
(RACH).
A major role is played in the layout and evaluation of any empirical wireless structure to manifest is the goal of this paper that counterfeit mode architectures affect counterfeit conduct, regarding structure accomplishment metrics, essentially and therefore, the excellent architecture should be explored in order to accomplish the most accurate and reliable results. It is found that the most analytical factors it is found that that actuate counterfeit mode accomplishment are counterfeit time, structure event organizing and
grade of adequate. It is, also, found that counterfeit time in relation to event existence in the real structure
along with the usage of modern architectural concepts such as multi-interweave technology complement
analytical issues too in the advancement of an adequate counterfeit organization for wireless communications. In order to evaluate the above findings an extensive empirical review has been
demeanored analysising several distinct events counterfeitorganizations towards presenting the relation
between channel designing collections, counterfeit time and structure accomplishment.
Cellular wireless systems like GSM suffer from congestion resulting in overall system degradation and poor service delivery. When the traffic demand in a geographical area is high, the input traffic rate will exceed thecapacity of the output lines. This work focused on homogenous wireless network (the network traffic and resource dimensioning that are statistically identical) such that the network performance
evaluation can be reduced to a system with single cell and a single traffic type. Such system can employa queuing model to evaluate the performance metric of a cell in terms of blocking probability.
Five congestion control models were compared in the work to ascertain their peculiarities, they are Erlang B, Erlang C, Engset (cleared), Engset (buffered), and Bernoulli. To analyze the system, an aggregate onedimensional Markov chain wasderived, such that it describes a call arrival process under the assumption
that it is Poisson distributed. The models were simulated and their results show varying performances, however the Bernoulli model (Pb5) tends to show a situation that allows more users access to the system and the congestion level remain unaffected despite increase in the number of users and the offered traffic into the system.
An approach to dsr routing qos by fuzzy genetic algorithmsijwmn
This document summarizes a research paper that proposes improvements to the DSR routing protocol in mobile ad hoc networks through the use of genetic and fuzzy algorithms. The proposed GA-DSR protocol adds link costs to route request packets and has the destination node use the received route requests as input to a genetic algorithm to find the two best routes. It then sends these routes back to the source in a route reply packet. The protocol also uses fuzzy logic to dynamically adjust the route update period based on route error counts. The researchers believe this approach can help improve quality of service in DSR routing by selecting optimal paths based on link costs and maintaining up-to-date routes.
Impact of client antenna’s rotation angle and height of 5g wi fi access point...ijwmn
This paper investigates the impact of antenna rotation’s angle at the receiver side and antenna height at
transmitter side on radio channel’s amount of fading. Amount of fading is considered as a measure of
severity of fading conditions in radio channels. It indicates how severe the fading level relative to Rayleigh
fading channel. The results give an input to optimize height of 5G Wi-Fi access point for better link
performance for different antenna’s rotation angles at receiver side. The investigation covers three
different indoor environments with different multipath dispersion levels in delay and direction domains;
lecture hall, corridor, and banquet hall.
ENHANCED THREE TIER SECURITY ARCHITECTURE FOR WSN AGAINST MOBILE SINK REPLI...ijwmn
Recent developments on Wireless Sensor Networks have made their application in a wide range
such as military sensing and tracking, health monitoring, traffic monitoring, video surveillance and so on.
Wireless sensor nodes are restricted to computational resources, and are always deployed in a harsh,
unattended or unfriendly environment. Therefore, network security becomes a tough task and it involves
the authorization of admittance to data in a network. The problem of authentication and pair wise key
establishment in sensor networks with mobile sink is still not solved in the mobile sink replication attacks.
In q-composite key pre distribution scheme, a large number of keys are compromised by capturing a
small fraction of sensor nodes by the attacker. The attacker can easily take a control of the entire network
by deploying a replicated mobile sinks. Those mobile sinks which are preloaded with compromised keys
are used authenticate and initiate data communication with sensor node. To determine the above problem
the system adduces the three-tier security framework for authentication and pair wise key establishment
between mobile sinks and sensor nodes. The previous system used the polynomial key pre distribution
scheme for the sensor networks which handles sink mobility and continuous data delivery to the
neighbouring nodes and sinks, but this scheme makes high computational cost and reduces the life time of
sensors. In order to overcome this problem a random pair wise key pre distribution scheme is suggested
and further it helps to improve the network resilience. In addition to this an Identity Based Encryption is
used to encrypt the data and Mutual authentication scheme is proposed for the identification and
isolation of replicated mobile sink from the network.
In ad hoc networks, routing plays a pertinent role. Deploying the appropriate routing protocol is very important in order to achieve best routing performance and reliability. Equally important is the mobility model that is used in the routing protocol. Various mobility models are available and each can have different impact on the performance of the routing protocol. In this paper, we focus on this issue by examining how the routing protocol, Optimized Link State Routing protocol, behaves as the mobility model is varied. For this, three random mobility models, viz., random waypoint, random walk and random direction are considered. The performance metrics used for assessment of Optimized Link State Routing protocol are Optimized Link State Routing protocol, end-to-end delay and packet delivery ratio.
A novel resource efficient dmms approach for network monitoring and controlli...ijwmn
In this paper, we propose a novel Distributed MANET Management System (DMMS) approach to use cross layer models to demonstrate a simplified way of efficiently managing the overall performance of individual network resources (nodes) and the network itself which is critical for not only monitoring the traffic, but also dynamically controlling the end-to-end Quality of Service (QoS) for different applications. In the proposed DMMS architecture, each network resource maintains a set of Management Information Base (MIB) elements and stores resource activities in their abstraction in terms of counters, timer, flag and threshold values. The abstract data is exchanged between different management agents residing in different resources on a need-to-know basis and each agent logically executes management functions locally to develop understanding of the behavior of all network resources to ensure that user protocols can function smoothly. However, in traditional network management systems, they collect statistical data such as resource usage and performance by spoofing of resources. The amount of data that is exchanged with other resources through management protocols that can be extremely high and the bandwidth for overhead management functions increases significantly. Also, the data storage requirements in each network resource for management functions increases and become inefficient as it increases the power usage for processing. Our proposed scheme targets at solving the problems.
Mobility models for delay tolerant network a surveyijwmn
Delay Tolerant Network (DTN) is an emerging networking technology that is widely used in the
environment where end-to-end paths do not exist. DTN follows store-carry-forward mechanism to route
data. This mechanism exploits the mobility of nodes and hence the performances of DTN routing and
application protocols are highly dependent on the underlying mobility of nodes and its characteristics.
Therefore, suitable mobility models are required to be incorporated in the simulation tools to evaluate DTN
protocols across many scenarios. In DTN mobility modelling literature, a number of mobility models have
been developed based on synthetic theory and real world mobility traces. Furthermore, many researchers
have developed specific application oriented mobility models. All these models do not provide accurate
evaluation in the all scenarios. Therefore, model selection is an important issue in DTN protocol
simulation. In this study, we have summarized various widely used mobility models and made a comparison
of their performances. Finally, we have concluded with future research directions in mobility modelling for
DTN simulation.
A cross layer delay-aware node disjoint multipath routing algorithm for mobil...ijwmn
Mobile Ad Hoc Networks (MANETS) require reliable routing and Quality of Service(QoS) mechanism to
support diverse applications with varying and stringent requirements for delay, jitter, bandwidth, packets
loss. Routing protocols such as AODV, AOMDV, DSR and OLSR use shortest path with minimum hop
count as the main metric for path selection, hence are not suitable for delay sensitive real time
applications. To support such applications delay constrained routing protocols are employed. These
Protocols makes path selection between source and destination based on the delay over the discovered
links during routing discovery and routing table calculations. We propose a variation of a node-disjoint
Multipath QoS Routing protocol called Cross Layer Delay aware Node Disjoint Multipath AODV (CLDMAODV)
based on delay constraint. It employs cross-layer communications between MAC and routing
layers to achieve link and channel-awareness. It regularly updates the path status in terms of lowest delay
incurred at each intermediate node. Performance of the proposed protocol is compared with single path
AODV and NDMR protocols. Proposed CLDM-AODV is superior in terms of better packet delivery and
reduced overhead between intermediate nodes.
Analysis of security threats in wireless sensor networkijwmn
Wireless Sensor Network(WSN) is an emerging technology and explored field of researchers worldwide
in the past few years, so does the need for effective security mechanisms. The sensing technology
combined with processing power and wireless communication makes it lucrative for being exploited in
abundance in future. The inclusion of wireless communication technology also incurs various types of
security threats due to unattended installation of sensor nodes as sensor networks may interact with
sensitive data and /or operate in hostile unattended environments. These security concerns be addressed
from the beginning of the system design. The intent of this paper is to investigate the security related
issues in wireless sensor networks. In this paper we have explored general security threats in wireless
sensor network with extensive study.
Bandwidth aware on demand multipath routing in manetsijwmn
The document proposes a modification to the AOMDV routing protocol to utilize available bandwidth in MANETs. It describes enhancing AOMDV to select multiple paths during route discovery based on available bandwidth, and using periodic detector packets to monitor bandwidth on alternate paths. Simulation results showed this bandwidth-aware multipath approach improves end-to-end throughput, packet delivery ratio, and end-to-end delay compared to the original AOMDV protocol.
New strategy to optimize the performance of spray and wait routing protocolijwmn
Delay Tolerant Networks have been (DTN) have been developed to support the irregular connectivity often
separate networks. The main routing problem in this type of network is embarrassed by time that is
extremely long, since connections are intermittent and opportunistic. Routing protocols must take into
account the maximum constraint encountered in this type of environment , use effective strategies
regarding the choice of relay nodes and buffer management nodes to improve the delivery of messages and
the time of their delivery . This article proposes a new strategy that optimizes the routing Spray and wait.
The proposed method uses the information contained in the messages delivered mostly paths traversed by
the messages before arriving at their destination and the time when nodes have receive these messages.
Simulation results show that the proposed strategy can increase the probability of delivery and minimizing
overhead unlike FIFO technology used with the default routing ' sprat and wait'
Path constrained data gathering scheme for wireless sensor networks with mobi...ijwmn
This document summarizes a research paper on using mobile elements to gather data in wireless sensor networks. The paper proposes a heuristic algorithm called Graph Partitioning (GP) to address the K-Hop tour planning (KH-tour) problem of designing the shortest possible tour for a mobile element to visit a subset of sensor nodes called caching points, such that any node is at most k hops from the tour.
The GP algorithm works by first partitioning the sensor network graph into partitions where the depth of each partition is bounded by k hops. It then identifies the minimum number of caching points needed in each partition. Finally, it constructs the mobile element's tour to visit all the identified caching points.
Stochastic analysis of random ad hoc networks with maximum entropy deploymentsijwmn
In this paper, we present the first stochastic analysis of the link performance of an ad hoc network modelled
by a single homogeneous Poisson point process (HPPP). According to the maximum entropy principle, the
single HPPP model is mathematically the best model for random deployments with a given node density.
However, previous works in the literature only consider a modified model which shows a discrepancy in the
interference distribution with the more suitable single HPPP model. The main contributions of this paper
are as follows. 1) It presents a new mathematical framework leading to closed form expressions of the
probability of success of both one-way transmissions and handshakes for a deployment modelled by a
single HPPP. Our approach, based on stochastic geometry, can be extended to complex protocols. 2) From
the obtained results, all confirmed by comparison to simulated data, optimal PHY and MAC layer
parameters are determined and the relations between them is described in details. 3) The influence of the
routing protocol on handshake performance is taken into account in a realistic manner, leading to the
confirmation of the intuitive result that the effect of imperfect feedback on the probability of success of a
handshake is only negligible for transmissions to the first neighbour node.
Data mining is important process to extract the useful information and pattern from huge amount of data.
NS-2 is an efficient tool to build the environment of network. The results from simulate these environment
in NS-2 is trace file that contains several columns and lines represent the network events. This trace file
can be used to analyse the network according to performance metrics but it has redundant columns and
rows. So, this paper is to perform the data mining in order to find only the necessary information in
analysis operation to reduce the execution time and the storage size of the trace file.
Virtual 2 d positioning system by using wireless sensors in indoor environmentijwmn
A 2D location detection system is constructed by using Wireless Sensor Nodes (WSN) to create aVirtual
Fingerprint map, specifically designed for use in an indoor environment. WSN technologies and
programmable ZigBee wireless network protocols are employed. This system is based on radio-location
fingerprinting technique. Both Linear taper functions and exponential taper functions are utilized with the
received signal strength distributions between the fingerprint nodes to generate virtual fingerprint maps.
Thus, areal and virtual combined fingerprint map is generated across the test area. K-nearest
neighborhood algorithm has been implemented on virtual fingerprint maps, in conjunction with weight
functions used to find the coordinates of the unknown objects. The system Localization accuracies of less
than a grid space areproved in calculations.
Performance analysis of voip over wired and wireless networks network impleme...eSAT Journals
Abstract In this Paper, the objective of simulation models is presented to investigate the performance of VoIP codecs over WiMAX and
FDDI networks that specially design for Aden University. To assure if the University IP network is prepared and adequate for this
new type of traffic before adding any new components, Aden University IP network will be simulated by using OPNET simulation
software then the new VoIP service will be added to the University networks. Different parameters that represent the QoS like end
to end delay, jitter, traffic sends and traffic received, MOS are calculated and analyzed in both network scenarios.
Keywords: VoIP, Codecs, QoS, WiMAX, FDDI
This document evaluates the quality of service (QoS) of Voice over Internet Protocol (VoIP) over different broadband networks using the G.729A codec. Simulations were conducted using OPNET Modeler to compare QoS parameters such as mean opinion score, end-to-end delay, jitter, and throughput for VoIP over wired, wireless LAN, UMTS, and WiMAX networks. The results found that wired and WiMAX networks provided the best VoIP quality with high mean opinion scores and low delay and jitter. UMTS had the worst performance with high delay and packet loss affecting voice quality.
OPTIMIZING VOIP USING A CROSS LAYER CALL ADMISSION CONTROL SCHEMEIJCNCJournal
This document discusses optimizing VoIP quality over wireless networks using a cross-layer call admission control scheme. It proposes monitoring real-time control protocol reports and data rates at the MAC layer to determine when quality is degraded. When quality degrades due to issues like network congestion or variable transmission rates, the solution is to adapt the packet size or codec type. The proposed scheme is simulated using a wireless campus network model to improve performance.
SPEECH QUALITY EVALUATION BASED CODEC FOR VOIP OVER 802.11P ijwmn
Voice over Internet Protocol (VoIP) may provide good services through Vehicular ad hoc networks
(VANETs) platform by providing services to many application scenarios range from safety to comfort.
However, VANETs networks introduce many challenges for supporting voice with QoS requirements. In
this paper, our study is based on Inter-Vehicle voice streaming rely on multi-hop fashion. For this task, a
performance evaluation of various audio CODECs will be analyzed by mean of simulations.
Furthermore, we test the impact of network environment on QoS metrics. To achieve good results,
CODECs behaviour is tested by using mobility information obtained from vehicular traffic generator. The
mobility model is based on the real road maps of an urban environment. Focusing on inter-vehicular
voice traffic quality, we provide simulations results in terms of both user level (MOS) metrics and
network level (such as Losses). According to this performance evaluation, we show that G.723.1 CODEC
worked well in the urban VANET environment.
Investigation and Evaluation of IEEE 802.11n Wlans Link Features Performance ...pijans
For an efficient design of wireless local-area networks (WLANs), the simulation tools are important to accurately estimate the IEEE 802.11n/ac link features for WLANs. However, this true simulation of network behavior is critical in designing high-performance WLANs. Through testing, analysis, and modeling of the proposed scheme repetitively, the design of the WLAN can be enhanced with a small budget before making its practical implementation. Many network simulation tools have been established to give solutions for this request and ns-3 is the most widely used tools among them by the research industry as an open-source network simulator. In this paper, we examine the various link features of the 802.11n WLANs under several conditions. We investigate the effects of 802.11n WLAN modulation and coding schemes (MCSs), 20MHz single channel or 40 MHz bonded channel, guard intervals (GI), frame aggregation, data encoding, number of antennas and their data rate, and link distance features of 802.11n WLAN in ns-3 when only a unique host connects with the access point (AP) and generates data traffic. Besides, the performance for an enterprise scenario proposed by the IEEE 802.11ax study group is evaluated when several hosts are simultaneously creating traffic with their associated APs. The results demonstrate that ns-3 support most of the link features of the 802.11n protocol with significant accuracy.
INVESTIGATION AND EVALUATION OF IEEE 802.11N WLANS LINK FEATURES PERFORMANCE ...pijans
For an efficient design of wireless local-area networks (WLANs), the simulation tools are important to accurately estimate the IEEE 802.11n/ac link features for WLANs. However, this true simulation of network behavior is critical in designing high-performance WLANs. Through testing, analysis, and modeling of the proposed scheme repetitively, the design of the WLAN can be enhanced with a small budget before making its practical implementation. Many network simulation tools have been established to give solutions for this request and ns-3 is the most widely used tools among them by the research industry as an open-source network simulator. In this paper, we examine the various link features of the 802.11n WLANs under several conditions. We investigate the effects of 802.11n WLAN modulation and coding schemes (MCSs), 20MHz single channel or 40 MHz bonded channel, guard intervals (GI), frame aggregation, data encoding, number of antennas and their data rate, and link distance features of 802.11n WLAN in ns-3 when only a unique host connects with the access point (AP) and generates data traffic. Besides, the performance for an enterprise scenario proposed by the IEEE 802.11ax study group is evaluated when several hosts are simultaneously creating traffic with their associated APs. The results demonstrate that ns-3 support most of the link features of the 802.11n protocol with significant accuracy.
Investigation and Evaluation of IEEE 802.11n WLANs Link Features Performance ...pijans
For an efficient design of wireless local-area networks (WLANs), the simulation tools are important to accurately estimate the IEEE 802.11n/ac link features for WLANs. However, this true simulation of network behavior is critical in designing high-performance WLANs. Through testing, analysis, and modeling of the proposed scheme repetitively, the design of the WLAN can be enhanced with a small budget before making its practical implementation. Many network simulation tools have been stablished to give solutions for this request and ns-3 is the most widely used tools among them by the research industry as an open-source network simulator. In this paper, we examine the various link features of the 802.11n WLANs under several conditions. We investigate the effects of 802.11n WLAN modulation and coding schemes (MCSs), 20MHz single channel or 40 MHz bonded channel, guard intervals (GI), frame aggregation, data encoding, number of antennas and their data rate, and link distance features of 802.11n WLAN in ns-3 when only a unique host connects with the access point (AP) and generates data traffic. Besides, the performance for an enterprise scenario proposed by the IEEE 802.11ax study group is evaluated when several hosts are simultaneously creating traffic with their associated APs. The results demonstrate that ns-3 support most of the link features of the 802.11n protocol with significant accuracy
Performance analysis of IEEE 802.11ac based WLAN in wireless communication sy...IJECEIAES
IEEE 802.11ac based wireless local area network (WLAN) is emerging WiFi standard at 5 GHz, it is new gigabit-per-second standard providing premium services. IEEE 802.11ac accomplishes its crude speed increment by pushing on three distinct measurements firstly is more channel holding, expanded from a maximum of 80 MHz up to 160 MHz modes. Secondly, the denser modulation, now using 256-QAM, it has the ability to increase the data rates up to 7 Gbps using an 8×8 multiple input multiple output (MIMO). Finally, it provides high resolution for both narrow and medium bandwidth channels. This work presents a study to improve the performance of IEEE 802.11ac based WLAN system.
Performance evaluation for outdoor wireless scenarios based on IEEE 802.11b/g...journalBEEI
Voice over Internet Protocol (VoIP) has evolved over the years, being a real-time service. VoIP has been coupled to different technologies, one of them is WiFi, which is one of the most used for wireless local area networks in domestic and commercial environments. In this paper, we evaluate the performance of wireless scenarios by considering VoIP traffic, based on WiFi technology in conformance with IEEE 802.11b/g in interfered outdoor scenarios, by considering an intrusive injection traffic technique, for codecs G711 (1 sample), G711 (2 samples), G723, G729 (2 samples), and G729 (3 samples), related to the main metrics associated to Quality of Service (QoS) parameters. Our results show the best performance was obtained with the codecs G723 and G729 (3 samples), obtaining up to 30 simultaneous voice connections with optimal values of delay, jitter and packet loss according to the recommendations given for VoIP by ITU-T, while the worst performance was obtained with the codec G711 (2 samples), obtaining only 5 simultaneous voice connections, reaching an efficiency loss of around 18% in a co-channel interference scenario.
Ftp and database statistics in wireless network environment for web client 2IAEME Publication
This paper models and simulates a wireless local area network (WLAN) using OPNET simulator to measure performance in a campus/university environment. Two scenarios are tested: 1) two WLAN sites each with 20 users (10 using a database application and 10 using FTP) connected through one access point without load balancing and 2) the same configuration with load balancing. Key performance metrics analyzed include response time, task processing time, media access delay, and throughput. The results show that load balancing significantly improves wireless and wired network performance for both database and FTP applications.
Investigating the performance of voip over wlan in campus networkAlexander Decker
This document discusses a simulation study of Voice over IP (VoIP) performance over a wireless campus network. The study investigated three factors:
1) Increasing the number of VoIP workstations from 6 to 30, which significantly increased jitter, delay, data dropped and decreased throughput. The network could only support 2-4 VoIP clients.
2) Using different voice coding schemes (G.711, G.723, G.729), which found that G.711 had the lowest jitter and delay but highest data dropped, while G.729 had the highest jitter and delay but lowest data dropped.
3) Increasing clients in video conferencing, which was not explicitly studied but would further degrade performance
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A NOVEL TWO-STAGE ALGORITHM PROTECTING INTERNAL ATTACK FROM WSNSIJCNC
Wireless sensor networks (WSNs) consists of small nodes with constrain capabilities. It enables numerous
applications with distributed network infrastructure. With its nature and application scenario, security of
WSN had drawn a great attention. In malicious environments for a functional WSN, security mechanisms
are essential. Malicious or internal attacker has gained attention as the most challenging attacks to
WSNs. Many works have been done to secure WSN from internal attacks but most of them relay on either
training data set or predefined thresholds. It is a great challenge to find or gain knowledge about the
Malicious. In this paper, we develop the algorithm in two stages. Initially, Abnormal Behaviour
Identification Mechanism (ABIM) which uses cosine similarity. Finally, Dempster-Shafer theory (DST)is
used. Which combine multiple evidences to identify the malicious or internal attacks in a WSN. In this
method we do not need any predefined threshold or tanning data set of the nodes.
This document analyzes the performance of different VoIP codecs over a WiMAX network using the network simulator NS2. The simulation varies parameters like the number of nodes and type of VoIP codec. Performance is evaluated based on metrics like throughput, average delay, and jitter. Results are presented graphically to compare these metrics for different codecs and number of nodes. The document provides background on VoIP codecs, IEEE 802.16 service flow classes, and simulation setup using NS2.
An analysis of a large scale wireless image distribution system deploymentConference Papers
This document describes two setups of a wireless image distribution system:
1. A setup using commercial network equipment like access points and an access controller, which supported over 125 connected devices and provided sufficient bandwidth for the system load in an auditorium with 159 seats.
2. A setup using a wireless mesh network of three NerveNet nodes, which provided a quick and easy setup without wired connections but needs further performance improvements. Results from tests of both setups were analyzed to evaluate the network technologies for smart community applications.
An analysis of a large scale wireless image distribution system deploymentConference Papers
This document describes two setups of a wireless image distribution system:
1. A setup using commercial network equipment like access points and an access controller, which supported over 125 connected devices and provided sufficient bandwidth for the system load during a conference.
2. A setup using a wireless mesh network of NICT NerveNet nodes, which provided a quick and easy setup but had room for improved performance based on analysis of the wireless backhaul links and connected devices. Both setups were tested and analyzed to evaluate network technologies for smart community applications.
SERVICES AS PARAMETER TO PROVIDE BEST QOS : AN ANALYSIS OVER WIMAXijngnjournal
In this paper it is proposed to provide the QoS to the user by using the degradation of service under hostile environment being itself be a parameter to improve the QoS. Here the relation between the service and environment of its best performance drawn on the basis of simulation and analysis .The service then taken as a parameter to decide present environment of the user and to take measurable steps to improve the QoS either doing handover to nearby station or increasing power or to provide some marginal bandwidth etc.All analysis done over a WiMax network i.e. being designed and simulated using the Qualnet wireless simulator.
Low-cost wireless mesh communications based on openWRT and voice over interne...IJECEIAES
Technology makes it easier for us to communicate over a distance. However, there are still many remote areas that find it difficult to communicate. This is due to the fact that communication infrastructure in some areas is expensive to build while the profit will be low. This paper proposes to combine voice over internet protocol (VoIP) over mesh network implemented on openWRT router. The routers are performing mesh functions. We set up a VoIP server on a router and enabled session initiation protocol (SIP) clients on other routers. Therefore, we only need routers as a means of communication. The experiment showed very good results, in the line-of-sight (LOS) condition, they are limited to reception distances up to 145 meters while in the non-lineof-sight (NLOS) condition, they are limited to reception distances up to 55 meters.
Zigbee Based Wireless Sensor Networks for Smart CampusIJMER
The document discusses simulations of Zigbee-based wireless sensor networks using different topologies with static and dynamic positioning of the Zigbee coordinator node. The simulations analyzed the effect on throughput and end-to-end delay. Results showed that a tree topology with a mobile coordinator had the highest throughput. A mesh topology, whether with static or dynamic coordinator, produced the lowest end-to-end delay. The document concludes that making the coordinator node mobile generally provides better network performance than a static coordinator configuration.
EMPIRICAL PERFORMANCE EVALUATION OF ENHANCED THROUGHPUT SCHEMES OF IEEE802.11...ijwmn
This document summarizes previous research on evaluating the performance of enhanced throughput schemes in IEEE802.11 wireless area networks. It discusses how previous studies have analyzed coverage, signal strength, and throughput using simulations and empirical models. This study aims to build on previous work by evaluating IEEE802.11ac networks using real applications to analyze metrics like throughput, capacity, and reliability under various quality of service enhancement schemes like beamforming.
Similar to Performance analysis of voip traffic over integrating wireless lan and wan using different codecs (20)
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Infrastructure Challenges in Scaling RAG with Custom AI modelsZilliz
Building Retrieval-Augmented Generation (RAG) systems with open-source and custom AI models is a complex task. This talk explores the challenges in productionizing RAG systems, including retrieval performance, response synthesis, and evaluation. We’ll discuss how to leverage open-source models like text embeddings, language models, and custom fine-tuned models to enhance RAG performance. Additionally, we’ll cover how BentoML can help orchestrate and scale these AI components efficiently, ensuring seamless deployment and management of RAG systems in the cloud.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Performance analysis of voip traffic over integrating wireless lan and wan using different codecs
1. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
DOI : 10.5121/ijwmn.2014.6306 79
PERFORMANCE ANALYSIS OF VOIP TRAFFIC OVER
INTEGRATING WIRELESS LAN AND WAN USING
DIFFERENT CODECS
Ali M. Alsahlany1
1
Department of Communication Engineering, Al-Najaf Technical College, Foundation
of Technical Education, Iraq
ABSTRACT
A simulation model is presented to analyze and evaluate the performance of VoIP based integrated
wireless LAN/WAN with taking into account various voice encoding schemes. The network model was
simulated using OPNET Modeler software. Different parameters that indicate the QoS like MOS, jitter,
end to end delay, traffic send and traffic received are calculated and analyzed in Wireless LAN/WAN
scenarios. Depending on this evaluation, Selection codecs G.729A consider the best choice for VoIP.
KEYWORDS
VoIP, Codecs, QoS
1. INTRODUCTION
During the recent years, there is a growing trend in real time voice communication using
Internet protocol (IP). Voice over Internet Protocol (VoIP) is a technology that allows delivery
of voice communications over the Internet or other packet switched networks rather than the
traditional Public Switched Telephone Network (PSTN). Many VoIP applications are available
on the internet: Skype, Viber, Tango, and Yahoo messenger. All of these applications provide
good quality, and free calls. In VoIP the analogue voice signal of the transmitter is converted
into digital format before compression and encoding it into a stream of IP packets for
transmission to the receiver over IP network. At the receiving end, Digital to Analogue
Converter (DAC) works on regenerating the original analogue voice signal after reassemble
received IP packets in order and processing it [1].
There are many authors have worked on various Quality of Service (QoS) parameters using
different service classes in different network types. A study was conducted on various quality
parameters impacting on the VOIP service performance. The study refers that these parameters
of QoS are required to increase the performance of a VoIP. Researchers in [2], have compared
the performance of the VoIP in both Ethernet LAN (802.3) and Wireless LAN (IEEE 802.11).
They examine how VoIP performs in two different network setups and analyzes the results
obtained using OPNETsimulator. They also examine the optimization of IEEE 802.11e for QoS
using the priorities to provide real time service for VoIP. Various QoS parameters like
throughput and average delay for VoIP using different protocols are analyzed in Ref. [3] using
OPNET simulator. Simulation results show that the Optimized Link State Routing protocol has
better performance in terms of throughput and average delay. Similar analysis has been
conducted in [4] to analyze the QoS of VoIP deployment over WiMAX network and compare
2. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
80
the performance obtained over various service classes. In [5] authors discussed a handoff
mechanism effect on VoIP traffic in Wireless LANs for intra and inter mobility. The study was
oriented towards the assessment of the quality of the voice traffic, the packet delays, and delay
jitter during the handover operation. Atiur et.al. [6], used an analytical model to estimate the
VoIP call capacity of IEEE 802.11g wireless LAN to support single hop networks and multi-
hop VoIP services. The authors discovered that, the number of hops between VoIP transmitters
in IEEE 802.11g wireless LAN has effects on call quality. Hussein et al. [7], conducted a
comparison between different queue algorithms. The authors found that Priority queue and
Weight Fair Queuing algorithms are the most appropriate to improve QoS for VoIP. In [8]
authors used VoIP as the multimedia measurement to identify the main limitations for
enhancing QoS in Wireless LANs, compared to wired networks.
However, none of them have presented accurate approximations to predict the performance of
QoS for VoIP when various audio codec schemes are used. Also, most of these studies were
performed in a small distance network area without taking real WAN as a one of real
application environment. In his paper, the OPNET simulator used to implement the proposed
VoIP Network. The simulation model for the proposed network is a private network for a
company has two locations located at two different countries around the world in order to
simulate the communications between two locations as a long distance and the same location as
a local. The major factors that affect on the QoS for VoIP such as: mean opinion score (MOS),
average end to end delay, jitter, traffic send, and traffic received are analyzed according to
International Telecommunication Union (ITU) standards.
A comparison was carried out between different codecs (G.711, G.729A and G.723.1) which
are the most appropriate to improve QoS for VoIP.
The rest of this paper is organized as follows. Section 2 focus on VoIP codec schemes. The
model design and configuration networks are described in Section 3. Section 4 presents
simulation results and analysis. Finally, Section 5 concludes the paper.
2. VOIP CODECS
A codec is the term used for the word coder-decoder, converts of analog audio signals into
compressed digital form for transmission and then back into an uncompressed audio signal
for the reception. There are different codec types based on the selected sampling rate, data
rate, and implemented compression. the most common codecs used for VoIP applications
are G.711, G722, G723, G726, G728, G729A, etc. each of which varies in the sound
quality, the bandwidth required, the computational requirements, encoding algorithm and
coding delay [3, 9, 10]:
In our evaluations codecs of ITU standards for audio compression and decompression are
used. Following table lists some features of the most common codecs: G.711, G.723.1, and
G.729A.
3. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
81
Table 1: Features of the most common codecs: G.711, G.723.1 and G.729A
IUT-T
Codec
Algorithm
Codec
Delay
(ms)
Bit Rate
(Kbps)
Packets
Per
Second
IP Packet
Size
(bytes)
Comments
G.711 pulse-code
modulation (PCM)
0 .375 64 100 120
Delivers precise speech
transmission. Very low
processor requirements
G.723.1
Multipulse
maximum likelihood
quantization/algebra
c-code excited linear
prediction
97.5 5.3 33 60
High compression with
high quality audio. Can
use with dial-up. Lot of
processor power
G.729A
Conjugate Structure
– Algebraic Code
Excited Linear
Prediction (ACELP)
35 8 100 50
Excellent bandwidth
utilization. Error
tolerant
3. NETWORK MODEL DESCRIPTION
Our simulation approach uses OPNET simulator for network modeling. OPNET simulator is an
authoritative communication system simulator developed by OPNET Technologies.
This simulation model was run in three different scenarios to evaluate the difference in
performance and to determine the best audio encoding schemes of utilizing VoIP over
integrating Wireless LAN/WAN. All the scenarios follows the same structure and the same
topology. The basic difference in all the scenarios is with the configuration of the corresponding
application and the profiles. As one scenario is implemented with the codec G.711, G.723.1,
and G.729.1. Various comparisons conducted to find the values of various parameters.
The simulation model for the network under study is illustrated in Figure 1. The Application
Config, Profile Config, Mobility Config and QoS Attribute Config are included in the model.
The Wireless LANs has been considered as the components of the whole network and its nodes
are using VoIP services.
A frame relay model supporting Permanent Virtual Circuit (PVC) implemented for the WAN.
At each end of the frame relay we had subnets. Inside these subnets was a Wireless LAN
environment. The Wireless LAN environments consisted of 3 Routers and 5 workstations in
each Router. All the Routers connected together using a Switch. At wireless subnet_0 as shown
in Figure 2, Two Servers were connected to the Ethernet Router titled VoIP_Server and Server.
The VoIP_Server handled the VOIP traffic and the Server handled the FTP and HTTP traffic.
All The Wireless LAN Routers were connected to the frame relay via an Ethernet Router that
connected the Switch. The WAN and Wireless LAN were both star topologies.
4. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
82
Figure 1: The Simulation Network Model
Figure 2: The wireless subnet_0
5. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
83
Figure 3: The wireless subnet_1
3.1 BASIC PARAMETER
The Point to Point WAN was connected directly to the Ethernet Router in each subnet using a
DS0 line. The model name of the link was ‘point_to_point_link_adv’. The Wireless LAN
environment used 1Gbps Ethernet cable for all the wired connections to the Router, Switch, and
Servers. The OPNET model name for the Servers was ‘ethernet_server’. Each Wireless LAN
environment contains a Router and 2 fixed wireless workstations and 3 moving wireless
workstations in each Router. All these wireless nodes use VoIP services. The Routers and
workstations were using 802.11g running at a data rate of 54 Mbps. There were a total of 15
workstations in each subnet. The workstations were generating traffic across the WAN and the
Wireless LAN environment to simulate a real office environment. The Routers OPNET model
name was ‘wlan_ethernet_slip4_adv. The fixed VoIP workstation model and the moving VoIP
workstation model name were ‘wlan_wksn_adv’.
All the parameters using in the Wireless LAN environment have the same value in the same
subnet. The Wireless LAN attributes are shown in Table 2.
Table 2: Parameters used in simulation
Parameter Value
Physical characteristic IEEE 802.11g
Data Rate 54 Mbps
Roaming Capability Enable
Transmit Power 0.005 W
Power Threshold -95 db
Short Retry Limit 7
Long Retry Limit 4
6. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
84
3.2 APPLICATION, PROFILE, AND MOBILITY CONFIGURATIONS
Application Definitions were where the applications were created for traffic generation on the
network. There are 3 applications used in each scenario. These are VoIP, FTP and web
browsing applications. The important one was VoIP. In the Voice category IP Telephony
selected for configuration VoIP. In the VoIP application, voice attributes setup as codec scheme
G.711 for scenario 1; G.723.1 for scenario 2; and G.729A for scenario 3. G.729A operates at a
bit rate of 8 Kbps, G.723.1 operates at a bit rate of 5.3/6.3 Kbps and G.711 operates at a bit rate
of 64 Kbps. For the QoS scenarios the VoIP table type of service (ToS) was changed to 8 to
give voice priority. Other parameters that were set for this project were file transfer and web
browsing. For each of these applications mentioned there was a heavy usage parameter set for
each one.
Profile Configuration describes the activity applications used by users through a period of time.
The FTP_Profile was using VoIP, FTP, Web Browsing and File Transfer with light usage
parameters. VoIP_Profile was only using VoIP applications, these were the dedicated IP
phones. All the Profiles configured to run simultaneously to allow more than one application to
operate at the same time.
The Profile Definition for VoIP traffic is configured that the first VoIP call is starting at 100
second (60 seconds offset time + 40 seconds start time) of the simulation, after that one VoIP
call is added after 1 second. The addition of VoIP calls is prepared by repeating the voice
application in the Profile Definition. This procedure continues till the end of the simulation.
Mobility Configuration setup the trajectory for the wireless mobile nodes in the Wireless LAN
environments. There were two vector mobility profiles. The differences in the profiles were
mobility speed.
4. SIMULATION RESULTS AND ANALYSIS
The following figures are obtained after collecting statistics by using OPNET Modeler
simulation tool. Each figure shows a comparative picture of the three scenarios. All the three
scenarios are using a different audio codec scheme such as G.911, G.923 and G.929. After
successfully running the simulation, The result shows the impact of different codecs on different
QoS parameters in a VoIP network. Following are the figures that show different QoS
parameters like MOS, Voice packet end to end delay (sec), Voice jitter (sec), Voice traffic
sends (packet/sec) and Voice traffic received (packet/sec).
The most widely used QoS metric in VoIP applications is MOS. The MOS value describes the
voice perception quality. The average MOS value for the three codecs is represented in Figure
4. Codecs G. 711 and G. 729A have acceptable MOS values 3.685 and 3.067, respectively. On
the other hand, the MOS value for G. 723.1 is 2.557 which indicates that the quality of service
is poor if this codec used.
7. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
85
Figure 4: Average voice MOS under various codecs
Average end to end delay metric is shown in Figure 5. G.729A presents the best performance
with respect to other codecs. These results are due to transfer rate and packet size. The low
packets transfer and the larger packet size, the more time is required to process them. The
relatively high transfer rate (8 kbps) and low packet size (20 bytes) for G.729A make G.729A
the ideal codecs. Otherwise, G.723.1 and G.711 suffered highest delay than G.729A for the
reason that it has the lowest bit rate (5.3 kbps for G.723.1) and larger packet size (160 bytes for
G.711). In turn, the end to end delay is increased with transfer rate and packet size.
8. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
86
Figure5: Average voice packet End to End delay (sec) under various audio codecs
Figure 6 describes the average voice jitter comparison using different codecs. From the Figure,
the variation of the codec G.729A is minimum and approximately constant throughout the
simulation. The average voice jitter variation in case of codec G.723.1 is higher than the other
two codecs at the earlier time of simulation, but after some time it falls down. The jitte
variation in case of G.711 lies between two other audio codecs. The voice jitter threshold for
smooth communication in VoIP network is about 1 ms [11] so audio codec G.729A gives better
results than audio codecs G.711 and G.723.1 respectively. So there is a high increase in jitter as
audio codecs G.711 and G.723.1 are added to the network. This increase in voice jitter makes
the voice difficult to understand due to arriving packets at different time . The use audio codec
G.729A will make the jitter less and best performance of VoIP application in Integrating
Wireless LAN and WAN.
9. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
87
Figure 6: Average Jitter under various audio codecs
Average voice traffic sent and received is presented in Figure 7. Any network to be more
efficiency these two traffics must be equal. The traffic received by the network with codec G.
729 is less deviated from the traffic sent comparatively with codec G.723.1 and G.711. This
analysis indicates that the noise added in the G.729A network is less when compared to the
other networks, so this codec is more efficient.
10. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
88
Figure 7: Average voice traffic sent and received under various audio Codecs.
5. CONCLUSION
In this paper, analysis and evaluation of the QoS performance for VoIP traffic under various
voice codecs was carried out. The use of codecs appropriately is very important in the
implementation of VoIP to generate maximum QoS value. The result shows a selection of
G.729A codec in a simulation gives a significant result for the performance of VoIP that codec
G.729A has acceptable MOS value and less deviation of received to transmit packet as
compared to G.711 and G.723.1 also average delay like end to end delay and Voice jitter is
lesser in codec G.729A as compared to the other two referenced codecs.
11. International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 2014
89
REFERENCES
[1] Y. Jung, and C. Manzano, "Burst packet loss and enhanced packet loss-based quality model for
mobile voice-over Internet protocol applications," Journal of IET Commun., Vol. 8, Iss. 1, pp. 41–49,
2014.
[2] K. Neupane, and et al, " Measuring the Performance of VoIP over Wireless LAN," In Proceedings of
the 2011 conference on Information technology education (SIGITE '11), New York, USA, pp. 269-
274, 2011.
[3] S. Anand, and et al, " Performance Analysis of VoIP Traffic using various Protocols and Throughput
enhancement in WLANs," International Conference on Computer, Communication and Electrical
Technology," March 18-19, pp. 176-180, 2011.
[4] T. Anouari, and A. Haqiq, " Performance Analysis of VoIP Traffic in WiMAX using various Service
Classes," International Journal of Computer Applications,Vol. 52, No.20, August, pp. 29-34, 2012.
[5] Abderrahmane Lakas, " Experimental Analysis of VoIP over Wireless Local Area Networks,"
Journal of Communications, Vol. 2, No. 4, June , pp. 3-9, 2007.
[6] M. Atiur, and et al, " An Analytical Approach for Voice Capacity Estimation Over WiFi Network
Using ITU-T E-Model," IEEE Transactions on Multimedia, Vol. 16, No. 2, pp. 360-372, Feb., 2014.
[7] Hussein, and et al, " The Effects of Different Queuing Algorithmswithin the Router on QoS VoIP
application Using OPNET," International Journal of Computer Networks & Communications (IJCNC)
Vol.5, No.1, Jan , pp. 117-124, 2013.
[8] Ayman Wazwaz, and et al, " Analysis of QoS parameters of VOIP calls over Wireless Local Area
Networks" The 13th International Arab Conference on Information Technology ACIT', Dec.10-13,
pp. 409-414, 2012.
[9] T. Daengsi, and et al, "A Study of Perceptual VoIP Quality Evaluation with Thai Users and Codec
Selection Using Voice Quality - Bandwidth Tradeoff Analysis," ICT Convergence (ICTC), 2013
International Conference ,pp.691-696, 2013.
[10] S. Brak , and et al, " Speech Quality Evaluation Based CODEC for VOIP over 802.11P,"
International Journal of Wireless & Mobile Networks (IJWMN), Vol. 5, No. 2, April, pp. 59-69,
2013.
[11] U. R. Alo, and Nweke Henry, " Investigating the Performance of VOIP over WLAN in Campus
Network," Journal of Computer Engineering and Intelligent Systems, Vol.4, No.4, pp. 47-58, 2013.
Author
Ali M. Alsahlany (alialsahlany@yahoo.com) has got his MSc in communications
engineering from Basrah University in 2012. He is now working as a lecturer for
computer networks and wireless communications engineering in Communication
Engineering Department at Foundation of Technical Education. His area of interest
includes Computer Networks, Wireless and Mobile Networks, Optical
Communicationand , and Data Communications.