Multimedia streaming over Mobile Ad Hoc networks has been a very challenging issue due to the dynamic
behavior and uncertain nature of the channels. Transmission of real time video has bandwidth, delay and
loss requirements. However there are no Quality of Service (QoS) guarantees for video transmission in
today’s network. There are many challenging issues that need to be addressed in designing mechanisms for
video transmission, which include end-to-end Quality of Service, Bandwidth, Delay, Loss, Congestion, and
Heterogeneity. The Challenges of delivering Multi-media signals are even pronounced in Wireless
Networks (Mobile Ad Hoc Networks, Wireless Fidelity (Wi-Fi) and Cellular Networks) which are heavily
bandwidth constrained and have no fixed infrastructures. In this Research we provide a theoretical model
for minimum buffer size as a means of achieving smoother, higher quality streaming video. This Research
presents a general optimal video smoothing algorithm based on the concept of dynamically controlled
Coefficient of Variance (CV), which is the ratio of standard deviation of the end-to-end delay and the
expected value of the delay for each ensemble of packets being transmitted through the network. The results
discuss how the size of the “receive buffer” is affected by the allocated bandwidth for each source-pair end
users for supporting video streaming applications without any gaps. The simulation performance show that
the dynamic client buffer size based on measured bandwidth variation achieves negligible jitter in the video
streaming which is subjectively acceptable.
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.
Mobility Management Scheme for Mobile Communication Systems. A Reviewiosrjce
An intelligent mobility management scheme for mobile communication systems was studied. From
the result obtained, it was discovered that mobile to mobile call setup times showed a better performance as
compared to fixed network to mobile call setup and mobile to fixed call setup times. Moreover, increasing the
number of location areas within the switch does not affect inter-MSC handover and location updates since the
size of the switch coverage area remains the same. And when the location areas within the switch is increased,
intra-MSC location updates and handover also increases. Finally, user mobility directly affects the signaling
traffic for handover, location management, radio resource allocation and routing.
QoS Based Capacity Enhancement for WCDMA Network with Coding SchemeVLSICS Design
The wide-band code division multiple access (WCDMA) based 3G and beyond cellular mobile wireless networks are expected to provide a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). To serve diverse quality of service requirements of these networks it necessitates new radio resource management strategies for effective utilization of network resources with coding schemes. Call admission control CAC) is a significant component in wireless networks to guarantee quality of service requirements and also to enhance the network resilience. In this paper capacity enhancement for WCDMA network with convolutional coding scheme is discussed and compared with block code and without coding scheme to achieve a better balance between resource utilization and quality of service provisioning. The model of this network is valid for the real-time (RT) and non-real-time (NRT) services having different data rate. Simulation results demonstrate the effectiveness of the network using convolutional code in terms of capacity enhancement and QoS of the voice and video services.
Multimedia streaming over Mobile Ad Hoc networks has been a very challenging issue due to the dynamic
behavior and uncertain nature of the channels. Transmission of real time video has bandwidth, delay and
loss requirements. However there are no Quality of Service (QoS) guarantees for video transmission in
today’s network. There are many challenging issues that need to be addressed in designing mechanisms for
video transmission, which include end-to-end Quality of Service, Bandwidth, Delay, Loss, Congestion, and
Heterogeneity. The Challenges of delivering Multi-media signals are even pronounced in Wireless
Networks (Mobile Ad Hoc Networks, Wireless Fidelity (Wi-Fi) and Cellular Networks) which are heavily
bandwidth constrained and have no fixed infrastructures. In this Research we provide a theoretical model
for minimum buffer size as a means of achieving smoother, higher quality streaming video. This Research
presents a general optimal video smoothing algorithm based on the concept of dynamically controlled
Coefficient of Variance (CV), which is the ratio of standard deviation of the end-to-end delay and the
expected value of the delay for each ensemble of packets being transmitted through the network. The results
discuss how the size of the “receive buffer” is affected by the allocated bandwidth for each source-pair end
users for supporting video streaming applications without any gaps. The simulation performance show that
the dynamic client buffer size based on measured bandwidth variation achieves negligible jitter in the video
streaming which is subjectively acceptable.
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.
Mobility Management Scheme for Mobile Communication Systems. A Reviewiosrjce
An intelligent mobility management scheme for mobile communication systems was studied. From
the result obtained, it was discovered that mobile to mobile call setup times showed a better performance as
compared to fixed network to mobile call setup and mobile to fixed call setup times. Moreover, increasing the
number of location areas within the switch does not affect inter-MSC handover and location updates since the
size of the switch coverage area remains the same. And when the location areas within the switch is increased,
intra-MSC location updates and handover also increases. Finally, user mobility directly affects the signaling
traffic for handover, location management, radio resource allocation and routing.
QoS Based Capacity Enhancement for WCDMA Network with Coding SchemeVLSICS Design
The wide-band code division multiple access (WCDMA) based 3G and beyond cellular mobile wireless networks are expected to provide a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). To serve diverse quality of service requirements of these networks it necessitates new radio resource management strategies for effective utilization of network resources with coding schemes. Call admission control CAC) is a significant component in wireless networks to guarantee quality of service requirements and also to enhance the network resilience. In this paper capacity enhancement for WCDMA network with convolutional coding scheme is discussed and compared with block code and without coding scheme to achieve a better balance between resource utilization and quality of service provisioning. The model of this network is valid for the real-time (RT) and non-real-time (NRT) services having different data rate. Simulation results demonstrate the effectiveness of the network using convolutional code in terms of capacity enhancement and QoS of the voice and video services.
A Quality of Service Strategy to Optimize Bandwidth Utilization in Mobile Net...IDES Editor
The mobile network that supports network mobility
is an emerging technology. It is also referred as NEMO
(NEtwork MObility). It is more appropriate for mobile
platforms such as car, bus, train, air plane, etc. It is a great
challenge to provide Quality of Service (QoS) in NEMO. QoS
is a set of service requirements to be met by the network.
There are various parameters by which QoS is provided. This
paper concentrates on providing optimum bandwidth for data
traffic. The objective of this paper is to propose a strategy to
use Virtual Circuit (VC) approach in NEMO. It helps to
utilize the bandwidth effectively, to consume minimum time to
transfer the data and also to reduce overload of the mobile
router due to the minimum size of the header. Ultimately, it
gives better results to enhance the QoS in mobile networks.
How Dimetis is automating the management of hybrid network transports to provide realtime end-to-end traffic routing and QOS assurance for mission-critical video feeds
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
DEVICE-TO-DEVICE (D2D) COMMUNICATION UNDER LTE-ADVANCED NETWORKSijwmn
Device-to-Device (D2D) communication is a new technology that offer many advantages for the LTEadvanced
network such us wireless peer-to-peer services and higher spectral efficiency. It is also
considered as one of promising techniques for the 5G wireless communications system and used in so
many different fields such as network traffic offloading, public safety, social services and applications such
as gaming and military applications . The goal of this paper is to present advances on the current 3GPP
LTE-advanced system related to Device-to-Device (D2D). In this paper, we provide an overview of the
D2D types based on the communication spectrum of D2D transmission, namely Inband D2D
communication and Outband D2D communication. Then we present the advantages and disadvantages of
each D2D mode. Moreover, architecture and protocol enhancements for D2D communications under
LTE-A network are described.
IPTV IMPROVEMENT APPROACH OVER LTEWLAN HETEROGENEOUS NETWORKSIJCNCJournal
IPTV (Internet Protocol Television) includes several video components. The IMS (IP Multimedia
Subsystem) cannot differentiate between them what causes their treatment similarly. These sub-components
must have different priorities because they have distinct QoS constraints. In this paper, we suggest the
implementation of IPTV in a heterogeneous network that improved QoS by providing the capability to
prioritize the sub traffic according to the system administrator policy. A new IPv6 flow label field
definition was proposed that is ready for standardization. OPNET Modeler software is used to design our
approached architecture. The results show that IPTV users receive different amounts of video data based
on the stream's priority.
Optimization of Quality of Service in 4G Wireless NetworksIDES Editor
4G radio access technologies should be able to
provide different types of IP services. These services rang from
narrow-band to broadband, from non-real-time to real-time,
and from unicast to multicast broadcast applications. When
the need arises for different levels of user mobility the access
systems are required with advanced capabilities of radio
resource management and Quality of Service (QoS). We
present, in this paper, the different QoS approaches by the
various wireless and connectivity’s networks as well as the
issues that will face their implementations in 4G.
PERFORMANCE EVALUATION OF MOBILE WIMAX IEEE 802.16E FOR HARD HANDOVERIJCNCJournal
Seamless handover in wireless networks is to guarantee both service continuity and service quality. In
WiMAX, providing scalability and quality of service for multimedia services during handover is a main
challenge because of high latency and packet loss. In this paper, we created four scenarios using Qualnet
5.2 Network Simulator to analyze the hard handover functionality of WiMAX under different conditions.
The scenarios such as Flag with 5 and 10 sec UCD and DCD interval values, Random mobility scenario
and DEM scenario using 6 WiMAX Cells have been considered. This study is performed over the real
urban area of JNU where we have used JNU map for scenarios 1, 2 and 3 but for scenario 4, the JNU
terrain data has been used. Further, each BS of 6 WiMAX cell is connected to four nodes. All nodes of each
scenario are fixed except Node 1. Node 1 is moving and performing the handover between the different BSs
while sending and receiving real time traffics. Flag mobility model is used in Scenario 1, 2 and 4 to model
the movement of the Node 1 while we use random mobility model in sceanrio3. 5 seconds time interval is
used for Scenarios 1, 3, and 4 while 10 seconds time interval is used for scenario 2 to study the effect of
management messages load on handover. Further, the statistical measures of handover performance of
WiMAX in terms of number of handover performed, throughput, end-to-end delay, jitter, and packets
dropped are observed and evaluated.
Interworking qos management subsystem into ims based architecture multi provi...IJCNCJournal
The third-generation partnership project 3GPP and 3GPP2 have standardized the IP multimedia subsystem
(IMS) to provide ubiquitous and access network-independent IP-based services for next-generation
networks via merging cellular networks and the Internet. The IP Multimedia Subsystem (IMS) seems to be
the technology that will prevail in Next Generation Networks (NGNs). The users wish to communicate
through collections of networks using different protocols; rendering service mapping from one network to
another with the similar QoS is a complex issue thereby. The heterogeneous networks are collections of
communication platforms using different protocols. This heterogeneity implies the need to offer many
different services on the market within short time. In this paper we propose a heterogeneous network model
based on the IMS that provides guaranteed QoS. Our method presents, in the first, an informational
solution. Decisional information is added to the HSS basis to enrich the knowledge base, which is
expressed under the form of "profile of QoSR", where the new information informs directly the decisions to
be taken according to the user’s profile (preferences QoS and pricing, bandwidth, location ...). In the
second, a solution for multi provider’s context which can allow a subscriber to register with one or more
operator(s) according to QoS offered. Thirdly, a mechanism which can be deployed in heterogeneous
networks to preserve the original QoS values of the user session and thus eliminate the cumulative effect of
QoS rounding across the entire communication path. And it is feasible via the “Interworking QoS
Management Sub-network” while adding the new interworking management components, namely: SICs,
DIC, QPA AS and HSS-PQoSR.
Using Bandwidth Aggregation to Improve the Performance of Video Quality- Adap...paperpublications3
Abstract: Smart phone provides many multimedia services for mobile users. Most of these smart phones are equipped with multiple wireless network interfaces (that support real time video processing. How to use efficiently and cost-effectively utilize multiple links to improve video streaming quality over multiple wireless access networks . In order to maintain high video streaming quality while reducing the wireless service cost, In Video quality-adaptive streaming, the optimal video streaming process with multiple links is formulated as a Markov Decision Process (MDP). The reward function is designed to consider the quality of service (QoS) requirements for video traffic, such as the startup latency, playback fluency, average playback quality, playback smoothness and wireless service cost. To solve the MDP in real time, Quality-adaptive streaming propose an Adaptive search Depth algorithm to obtain a sub-optimal solution.
A NOVEL SLOTTED ALLOCATION MECHANISM TO PROVIDE QOS FOR EDCF PROTOCOLIAEME Publication
The IEEE 802.11e EDCF mechanism cannot guarantee the QOS of high-priority traffic as the bandwidth consumption of the low-priority traffic increases. Also, in the presence of high priority traffic dampen link utilization of low priority traffic. To overcome these problems, we propose the Novel mechanism in our research that extends IEEE 802.11e EDCF by introducing a Super Slot and Virtual Collision. Compared to EDCF, our proposed approach has EDCF has two advantages: (a) Higher priority traffic achieves Quality of service regardless of the amount of low priority traffic, and (b) Low priority traffic obtains a higher throughput in the presence of same amount of high priority traffic.
Accurate wireless channel modeling for efficient adaptive Forward Error Corre...IJERD Editor
In this paper, we evaluate the impact of accurate 802.11 based wireless channel modeling on the
efficiency of dynamic Forward Error Correction (FEC) schemes in Motion JPEG 2000 video streaming systems.
We derive a compromise on the suitable trace length for practical estimation of Packet Error Rate (PER) at
decoder side. We demonstrate the validity of the derived trade-off using a real JPEG 2000 based video streaming
system.
Automated deployment of data collection policies over heterogeneous shared se...Cyril Cecchinel
Smart buildings and smart cities rely on interconnected sensor networks that collect data about their environment to support various applications. Developing and deploying the data collection architectures of these systems is a challenging problem. The specificities of the sensor platforms compel software engineers to work at a low level. This make this activity tedious, producing code that badly exploit the network architecture, and hampering reuse of data collection policies. Moreover, several data collection programs cannot be guaranteed to be deployable on a shared infrastructure. We present an automated approach that supports (i) the definition of data collection policies at a higher level of abstraction, (ii) the representation of the diverse platforms and the network topology, and (iii) the automatic composition and deployment of the policies on top of heterogeneous sensing infrastructures following different strategies. The approach is tooled and has been assessed on both realistic and simulated deployments.
A Quality of Service Strategy to Optimize Bandwidth Utilization in Mobile Net...IDES Editor
The mobile network that supports network mobility
is an emerging technology. It is also referred as NEMO
(NEtwork MObility). It is more appropriate for mobile
platforms such as car, bus, train, air plane, etc. It is a great
challenge to provide Quality of Service (QoS) in NEMO. QoS
is a set of service requirements to be met by the network.
There are various parameters by which QoS is provided. This
paper concentrates on providing optimum bandwidth for data
traffic. The objective of this paper is to propose a strategy to
use Virtual Circuit (VC) approach in NEMO. It helps to
utilize the bandwidth effectively, to consume minimum time to
transfer the data and also to reduce overload of the mobile
router due to the minimum size of the header. Ultimately, it
gives better results to enhance the QoS in mobile networks.
How Dimetis is automating the management of hybrid network transports to provide realtime end-to-end traffic routing and QOS assurance for mission-critical video feeds
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
DEVICE-TO-DEVICE (D2D) COMMUNICATION UNDER LTE-ADVANCED NETWORKSijwmn
Device-to-Device (D2D) communication is a new technology that offer many advantages for the LTEadvanced
network such us wireless peer-to-peer services and higher spectral efficiency. It is also
considered as one of promising techniques for the 5G wireless communications system and used in so
many different fields such as network traffic offloading, public safety, social services and applications such
as gaming and military applications . The goal of this paper is to present advances on the current 3GPP
LTE-advanced system related to Device-to-Device (D2D). In this paper, we provide an overview of the
D2D types based on the communication spectrum of D2D transmission, namely Inband D2D
communication and Outband D2D communication. Then we present the advantages and disadvantages of
each D2D mode. Moreover, architecture and protocol enhancements for D2D communications under
LTE-A network are described.
IPTV IMPROVEMENT APPROACH OVER LTEWLAN HETEROGENEOUS NETWORKSIJCNCJournal
IPTV (Internet Protocol Television) includes several video components. The IMS (IP Multimedia
Subsystem) cannot differentiate between them what causes their treatment similarly. These sub-components
must have different priorities because they have distinct QoS constraints. In this paper, we suggest the
implementation of IPTV in a heterogeneous network that improved QoS by providing the capability to
prioritize the sub traffic according to the system administrator policy. A new IPv6 flow label field
definition was proposed that is ready for standardization. OPNET Modeler software is used to design our
approached architecture. The results show that IPTV users receive different amounts of video data based
on the stream's priority.
Optimization of Quality of Service in 4G Wireless NetworksIDES Editor
4G radio access technologies should be able to
provide different types of IP services. These services rang from
narrow-band to broadband, from non-real-time to real-time,
and from unicast to multicast broadcast applications. When
the need arises for different levels of user mobility the access
systems are required with advanced capabilities of radio
resource management and Quality of Service (QoS). We
present, in this paper, the different QoS approaches by the
various wireless and connectivity’s networks as well as the
issues that will face their implementations in 4G.
PERFORMANCE EVALUATION OF MOBILE WIMAX IEEE 802.16E FOR HARD HANDOVERIJCNCJournal
Seamless handover in wireless networks is to guarantee both service continuity and service quality. In
WiMAX, providing scalability and quality of service for multimedia services during handover is a main
challenge because of high latency and packet loss. In this paper, we created four scenarios using Qualnet
5.2 Network Simulator to analyze the hard handover functionality of WiMAX under different conditions.
The scenarios such as Flag with 5 and 10 sec UCD and DCD interval values, Random mobility scenario
and DEM scenario using 6 WiMAX Cells have been considered. This study is performed over the real
urban area of JNU where we have used JNU map for scenarios 1, 2 and 3 but for scenario 4, the JNU
terrain data has been used. Further, each BS of 6 WiMAX cell is connected to four nodes. All nodes of each
scenario are fixed except Node 1. Node 1 is moving and performing the handover between the different BSs
while sending and receiving real time traffics. Flag mobility model is used in Scenario 1, 2 and 4 to model
the movement of the Node 1 while we use random mobility model in sceanrio3. 5 seconds time interval is
used for Scenarios 1, 3, and 4 while 10 seconds time interval is used for scenario 2 to study the effect of
management messages load on handover. Further, the statistical measures of handover performance of
WiMAX in terms of number of handover performed, throughput, end-to-end delay, jitter, and packets
dropped are observed and evaluated.
Interworking qos management subsystem into ims based architecture multi provi...IJCNCJournal
The third-generation partnership project 3GPP and 3GPP2 have standardized the IP multimedia subsystem
(IMS) to provide ubiquitous and access network-independent IP-based services for next-generation
networks via merging cellular networks and the Internet. The IP Multimedia Subsystem (IMS) seems to be
the technology that will prevail in Next Generation Networks (NGNs). The users wish to communicate
through collections of networks using different protocols; rendering service mapping from one network to
another with the similar QoS is a complex issue thereby. The heterogeneous networks are collections of
communication platforms using different protocols. This heterogeneity implies the need to offer many
different services on the market within short time. In this paper we propose a heterogeneous network model
based on the IMS that provides guaranteed QoS. Our method presents, in the first, an informational
solution. Decisional information is added to the HSS basis to enrich the knowledge base, which is
expressed under the form of "profile of QoSR", where the new information informs directly the decisions to
be taken according to the user’s profile (preferences QoS and pricing, bandwidth, location ...). In the
second, a solution for multi provider’s context which can allow a subscriber to register with one or more
operator(s) according to QoS offered. Thirdly, a mechanism which can be deployed in heterogeneous
networks to preserve the original QoS values of the user session and thus eliminate the cumulative effect of
QoS rounding across the entire communication path. And it is feasible via the “Interworking QoS
Management Sub-network” while adding the new interworking management components, namely: SICs,
DIC, QPA AS and HSS-PQoSR.
Using Bandwidth Aggregation to Improve the Performance of Video Quality- Adap...paperpublications3
Abstract: Smart phone provides many multimedia services for mobile users. Most of these smart phones are equipped with multiple wireless network interfaces (that support real time video processing. How to use efficiently and cost-effectively utilize multiple links to improve video streaming quality over multiple wireless access networks . In order to maintain high video streaming quality while reducing the wireless service cost, In Video quality-adaptive streaming, the optimal video streaming process with multiple links is formulated as a Markov Decision Process (MDP). The reward function is designed to consider the quality of service (QoS) requirements for video traffic, such as the startup latency, playback fluency, average playback quality, playback smoothness and wireless service cost. To solve the MDP in real time, Quality-adaptive streaming propose an Adaptive search Depth algorithm to obtain a sub-optimal solution.
A NOVEL SLOTTED ALLOCATION MECHANISM TO PROVIDE QOS FOR EDCF PROTOCOLIAEME Publication
The IEEE 802.11e EDCF mechanism cannot guarantee the QOS of high-priority traffic as the bandwidth consumption of the low-priority traffic increases. Also, in the presence of high priority traffic dampen link utilization of low priority traffic. To overcome these problems, we propose the Novel mechanism in our research that extends IEEE 802.11e EDCF by introducing a Super Slot and Virtual Collision. Compared to EDCF, our proposed approach has EDCF has two advantages: (a) Higher priority traffic achieves Quality of service regardless of the amount of low priority traffic, and (b) Low priority traffic obtains a higher throughput in the presence of same amount of high priority traffic.
Accurate wireless channel modeling for efficient adaptive Forward Error Corre...IJERD Editor
In this paper, we evaluate the impact of accurate 802.11 based wireless channel modeling on the
efficiency of dynamic Forward Error Correction (FEC) schemes in Motion JPEG 2000 video streaming systems.
We derive a compromise on the suitable trace length for practical estimation of Packet Error Rate (PER) at
decoder side. We demonstrate the validity of the derived trade-off using a real JPEG 2000 based video streaming
system.
Automated deployment of data collection policies over heterogeneous shared se...Cyril Cecchinel
Smart buildings and smart cities rely on interconnected sensor networks that collect data about their environment to support various applications. Developing and deploying the data collection architectures of these systems is a challenging problem. The specificities of the sensor platforms compel software engineers to work at a low level. This make this activity tedious, producing code that badly exploit the network architecture, and hampering reuse of data collection policies. Moreover, several data collection programs cannot be guaranteed to be deployable on a shared infrastructure. We present an automated approach that supports (i) the definition of data collection policies at a higher level of abstraction, (ii) the representation of the diverse platforms and the network topology, and (iii) the automatic composition and deployment of the policies on top of heterogeneous sensing infrastructures following different strategies. The approach is tooled and has been assessed on both realistic and simulated deployments.
ADVANCED RAILWAY SECURITY SYSTEM (ARSS) BASED ON ZIGBEE COMMUNICATION FOR TRA...rashmimabattin28
The principle point of this paper is to build up an inserted framework to distinguishing rail track flaw sending message to close station utilizing ZIGBEE TECHNOLOGY.
MicroGrid and Energy Storage System COMPLETE DETAILS NEW PPT Abin Baby
A microgrid is a localized grouping of electricity generation, energy storage, and loads that normally operates connected to a traditional centralized grid (macrogrid). This single point of common coupling with the macrogrid can be disconnected. The microgrid can then function autonomously. Generation and loads in a microgrid are usually interconnected at low voltage. From the point of view of the grid operator, a connected microgrid can be controlled as if it were one entity.
Microgrid generation resources can include fuel cells, wind, solar, or other energy sources. The multiple dispersed generation sources and ability to isolate the microgrid from a larger network would provide highly reliable electric power. Produced heat from generation sources such as micro turbines could be used for local process heating or space heating, allowing flexible trade off between the needs for heat and electric power.
IoT (Internet of things) big data analytics is becoming important to process unimaginably large amounts of information and data that are obtained by the sensor embedded interconnected IoT devices. The typical IoT big data analytics system is Hadoop, an open-source software framework that supports data-intensive distributed applications, and the running of applications on large clusters of commodity hardware. Hadoop, that is based on the architectural framework MapReduce, collects both structured data and unstructured data, processes the collected data set in a distributed network cluster in parallel, and extracts valuable information from the processed data set within a short time.
END TO END QUALITY OF SERVICE ASSURANCE FOR MULTI-SERVICE PROVISIONING IN MOB...IJNSA Journal
Multimedia streaming over Mobile Ad Hoc networks has been a very challenging issue due to the dynamic behavior and uncertain nature of the channels. Transmission of real time video has bandwidth, delay and loss requirements. However there are no Quality of Service (QoS) guarantees for video transmission in today’s network. There are many challenging issues that need to be addressed in designing mechanisms for video transmission, which include end-to-end Quality of Service, Bandwidth, Delay, Loss, Congestion, and Heterogeneity. The Challenges of delivering Multi-media signals are even pronounced in Wireless Networks (Mobile Ad Hoc Networks, Wireless Fidelity (Wi-Fi) and Cellular Networks) which are heavily bandwidth constrained and have no fixed infrastructures. In this Research we provide a theoretical model for minimum buffer size as a means of achieving smoother, higher quality streaming video. This Research presents a general optimal video smoothing algorithm based on the concept of dynamically controlled Coefficient of Variance (CV), which is the ratio of standard deviation of the end-to-end delay and the expected value of the delay for each ensemble of packets being transmitted through the network. The results discuss how the size of the “receive buffer” is affected by the allocated bandwidth for each source-pair end users for supporting video streaming applications without any gaps. The simulation performance show that the dynamic client buffer size based on measured bandwidth variation achieves negligible jitter in the video streaming which is subjectively acceptable.
Enhancing qo s and qoe in ims enabled next generation networksgraphhoc
Managing network complexity, accommodating greater numbers of subscribers, improving coverage to support data services (e.g. email, video, and music downloads), keeping up to speed with fast-changing technology, and driving maximum value from existing networks – all while reducing CapEX and OpEX and ensuring Quality of Service (QoS) for the network and Quality of Experience (QoE) for the user. These are just some of the pressing business issues faced by mobileservice providers, summarized by the demand to “achieve more, for less.” The ultimate goal of optimization techniques at the network and application layer is to ensure End-user perceived QoS. The next generation networks (NGN), a composite environment of proven telecommunications and Internet-oriented mechanisms have become generally recognized as the telecommunications environment of the future. However, the nature of the NGN environment presents several complex issues regarding quality assurance that have not existed in the legacy environments (e.g., multi-network, multi-vendor, and multi-operator IP-based telecommunications environment, distributed intelligence, third-party provisioning, fixed-wireless and mobile access, etc.). In this Research Paper, a service aware policy-based approach to NGN quality assurance is presented, taking into account both perceptual quality of experience and technologydependant quality of service issues. The respective procedures, entities, mechanisms, and profiles are discussed. The purpose of the presented approach is in research, development, and discussion of pursuing the end-to-end controllability of the quality of the multimedia NGN-based communications in an environment that is best effort in its nature and promotes end user’s access agnosticism, service agility, and global mobility
In this project, we proposed a framework to support heterogenous traffic with different QoS demand in
WiMAX. This framework dynamically changes the bandwidth allocation (BA) for ongoing and new arrival
connections based on network condition and service demand. The objective is to efficiently use the
available bandwidth and provide QoS support in a fair manner. Dynamic allocation of spectrum prior to
transmission can mitigate the starvation problem of Non Real time application. The WFQ based dynamic
bandwidth allocation framework uses architecture that has packet scheduler scheme (PS), call admission
policy and a dynamic bandwidth allocation mechanism. By the simulation result we have showed that this
architecture could provide QoS support by being fair to all classes of services.
THE TECHNIQUES FOR ENHANCING BANDWIDTH LOAD BALANCING QOS AT LOCAL AREA NETWO...IJCI JOURNAL
Bandwidth load balancing is a critical technique for improving the quality of service (QoS) in local area networks (LANs). Insufficient load balancing and QoS utilization can lead to network congestion, reduced performance, latency, packet loss, and an overall degradation of network performance. This paper presents an overview of load balancing techniques, load balancing algorithms, QoS parameters, load balancing strategies, and considerations for calculating bandwidth. The challenges of implementing load balancing algorithms and preferences for their implementation are discussed. Accurate network measurements and monitoring, coordination between network devices, security and privacy considerations, and careful evaluation of load balancing algorithms are among the challenges faced. The paper also discusses optimization and monitoring of bandwidth use, including options such as increasing bandwidth, bandwidth throttling, and data transfer throttling. The findings presented in this paper provide insights into the importance of load balancing and QoS in LANs and offer guidance for addressing related challenges.
Comparative Analysis of Quality of Service for Various Service Classes in WiM...Editor IJCATR
Broadband access is an important requirement to satisfy user demands and support a new set of real time services and
applications. WiMAX, as a Broadband Wireless Access solution for Wireless Metropolitan Area Networks, covering large distances
with high throughput and is a promising technology for Next Generation Networks. Nevertheless, for the successful deployment of
WiMAX based solutions, Quality of Service (QoS) is a mandatory feature that must be supported. Quality of Service (QoS) is an
important consideration for supporting variety of applications that utilize the network resources. These applications include voice over
IP, multimedia services, like, video streaming, video conferencing etc. In this paper the performances of the MPEG-4 High quality
video traffic over a WiMAX network using various service classes has been investigated. To analyze the QoS parameters, the WiMAX
module developed based on popular network simulator NS-3 is used. Various parameters that determine QoS of real life usage
scenarios and traffic flows of applications is analyzed. The objective is to compare different types of service classes with respect to the
QoS parameters, such as, throughput, packet loss, average delay and average jitter.
Application-Based QoS Evaluation of Heterogeneous Networks csandit
Heterogeneous wireless networks expand the network capacity and coverage by leveraging the
network architecture and resources in a dynamic fashion. However, the presence of different
communication technologies makes the Quality of Service (QoS) evaluation, management, and
monitoring of these networks very challenging. Each communication technology has its own
characteristics while the applications that utilize them have their specific QoS requirements.
Although, the communication technologies have different performance assessment parameters,
the applications using these radio access networks have the same QoS requirements. As a
result, it would be easier to evaluate the QoS of the access networks and the overall network
configuration depending on the performance of applications running on them. Using such
application-based QoS evaluation approach, the heterogeneous nature of the underlying
networks and the diversity of their traffic can be adequately taken into account. In this paper,
we propose an application-based QoS evaluation approach for heterogeneous networks.
Through simulation studies, we show that this assessment approach facilitates better QoS
management and monitoring of heterogeneous network configurations.
APPLICATION-BASED QOS EVALUATION OF HETEROGENEOUS NETWORKS cscpconf
Heterogeneous wireless networks expand the network capacity and coverage by leveraging the network architecture and resources in a dynamic fashion. However, the presence of different communication technologies makes the Quality of Service (QoS) evaluation, management, and monitoring of these networks very challenging. Each communication technology has its own characteristics while the applications that utilize them have their specific QoS requirements. Although, the communication technologies have different performance assessment parameters, the applications using these radio access networks have the same QoS requirements. As a result, it would be easier to evaluate the QoS of the access networks and the overall network configuration depending on the performance of applications running on them. Using such application-based QoS evaluation approach, the heterogeneous nature of the underlying networks and the diversity of their traffic can be adequately taken into account. In this paper, we propose an application-based QoS evaluation approach for heterogeneous networks. Through simulation studies, we show that this assessment approach facilitates better QoS management and monitoring of heterogeneous network configurations.
Adaptive Bandwidth Management Model for Wireless Mobile Ad-hoc NetworkIJCNCJournal
The quality of service (QoS) component in a mobile ad-hoc network has an active role in the current network scenario. In a dynamic mobile ad hoc network, ensuring optimum QoS with a scarce network resource is a significant challenge. To achieve QoS, it is essential to adopt some effective and efficient mechanisms. We have proposed an adaptive bandwidth manager model (ABMM) which uses a bandwidthsharing concept along with the flexible bandwidth reservation algorithm (FBRA) for an effective, quick and authentic data transfer. During real-time data transfer, to make communication effective, we make use of bandwidth-sharing network design problems and the concept of reserving bandwidth in high-performance networks. In our proposed model we are concentrating on the maximum utilization of resources, and using the scheduling concept to provide the minimum required bandwidth guarantee to QoS flows. Our goal is to reduce the delay in data transfer and enhance the throughput while properly utilizing the system resources. Our simulation result also shows that our model improves the network performance.
ADAPTIVE BANDWIDTH MANAGEMENT MODEL FOR WIRELESS MOBILE AD-HOC NETWORKIJCNCJournal
The quality of service (QoS) component in a mobile ad-hoc network has an active role in the current
network scenario. In a dynamic mobile ad hoc network, ensuring optimum QoS with a scarce network
resource is a significant challenge. To achieve QoS, it is essential to adopt some effective and efficient
mechanisms. We have proposed an adaptive bandwidth manager model (ABMM) which uses a bandwidthsharing concept along with the flexible bandwidth reservation algorithm (FBRA) for an effective, quick and
authentic data transfer. During real-time data transfer, to make communication effective, we make use of
bandwidth-sharing network design problems and the concept of reserving bandwidth in high-performance
networks. In our proposed model we are concentrating on the maximum utilization of resources, and using
the scheduling concept to provide the minimum required bandwidth guarantee to QoS flows. Our goal is to
reduce the delay in data transfer and enhance the throughput while properly utilizing the system resources.
Our simulation result also shows that our model improves the network performance.
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.
In this paper, an application-based QoS evaluation approach for heterogeneous networks is proposed.It is possible to expand the network capacity and coverage in a dynamic fashion by applying heterogeneous wireless network architecture. However, the Quality of Service (QoS) evaluation of this type of network architecture is very challenging due to the presence of different communication technologies. Different communication technologies have different characteristics and the applications that utilize them have unique QoS requirements. Although, the communication technologies have different performance measurement parameters, the applications using these radio access networks have the same QoS requirements. As a result, it would be easier to evaluate the QoS of the access networks and the overall network configuration based on the performance of applications running on them. Using such applicationbased QoS evaluation approach, the heterogeneous nature of the underlying networks and the diversity of their traffic can be adequately taken into account. Through simulation studies, we show that the application performance based assessment approach facilitates better QoS management and monitoring of heterogeneous network configurations.
ANALYTIC HIERARCHY PROCESS FOR QOS EVALUATION OF MOBILE DATA NETWORKSIJCNCJournal
The widespread demand for data applications over mobile networks requires that service providers guarantee a well-defined quality of service (QoS) for subscribers. Evaluating the QoS provided by service providers within a geographical area to determine which network provides the best QoS is a challenging task. The complex nature of mobile networks with multi-criteria and conflicting factors makes good decision making difficult. This paper presents a measurement-based method called Analytic Hierarchy Process (AHP) for evaluating QoS in application-specific and user-centric data on 3G mobile networks. The evaluation problem is formulated as a multi-criteria decision problem. Latency, jitter, data loss, and throughput are the parameters collected as criteria in drive testing over the mobile network. Decision matrix is applied to solve the problem by reaching a final ranking of the network based on the collected measured values of the problem parameters. A case study of 3G mobile networks in Uyo metropolis is used to show how this approach can be effective in ranking the QoS in data applications to determine which network provides the best QoS based on users’ perception of quality. The implemented results in Java indicate that Etisalat network is the alternative that offers the best QoS for web browsing application based on measured criteria. This is followed by Airtel and then MTN, while Glo is ranked least. The result provides useful information to decision makers for performance improvement on service quality.
RESOURCE ALLOCATION ALGORITHMS FOR QOS OPTIMIZATION IN MOBILE WIMAX NETWORKSijwmn
WiMAX is based on the standard IEEE 802.16e-2009 for wireless access in Metropolitan Area Networks. It
is one of the solutions for 4G IP based wireless technology. WiMAX utilizes Orthogonal Frequency
Division Multiple Access which also supports Multicast and Broadcast Service with appropriate
Modulation and Coding Scheme. Presently, Scheduling and Resource allocation algorithm in Opportunistic
Layered Multicasting provides multicasting of layered video over mobile WiMAX to ensure better QoS.
Initially, the knowledge based allocation of subcarriers is used for scheduling. In addition, to reduce the
burst overhead, delay and jitter, SWIM (Swapping Min-Max) algorithm is utilized. Another promising
technology that can greatly improve the system performance by exploring the broadcasting nature of
wireless channels and the cooperation among multiple users is the Cooperative Multicast Scheduling
(CMS) technique. The simulation results show, Swapping Min-Max performs better with lesser number of
bursts, Zero jitter and with optimal throughput. The results with Cooperative Multicast Scheduling show
the enhanced throughput for each member in the Multicasting Scenario.
Multi-Criteria Handoff Decision Algorithms In Wireless Networksiosrjce
IOSR Journal of Mobile Computing & Application (IOSR-JMCA) aims to cover innovative topics to research findings to trends analysis on Mobile Computing and Application related theories, technologies, methods, applications, and services from all engineering, business and organizational perspectives
QOS-BASED PACKET SCHEDULING ALGORITHMS FOR HETEROGENEOUS LTEADVANCED NETWORKS...ijwmn
The number of LTE (Long-Term Evolution) users and their applications has increased significantly in the
last decade, which increased the demand on the mobile network. LTE-Advanced (LTE-A) comes with many
features that can support this increasing demand. LTE-A supports Heterogeneous Networks (HetNets)
deployment, in which it consists of a mix of macro-cells, remote radio heads, and low power nodes such as
Pico-cells, and Femto-cells. Embedding this mix of base-stations in a macro-cellular network allows for
achieving significant gains in coverage, throughput and system capacity compared to the use of macrocells only. These base-stations can operate on the same wireless channel as the macro-cellular network,
which will provide higher spatial reuse via cell splitting. Also, it allows network operators to support
higher data traffic by offloading it to smaller cells, such as Femto-cells. Hence, it enables network
operators to provide their growing number of users with the required Quality of Service (QoS) that meets
with their service demands. In-order for the network operators to make the best out of the heterogeneous
LTE-A network, they need to use QoS-based packet scheduling algorithms that can efficiently manage the
spectrum resources in the HetNets deployment. In this paper, we survey Quality of Service (QoS) based
packet scheduling algorithms that were proposed in the literature for the use of packet scheduling in
Heterogeneous LTE-A Networks. We start by explaining the concepts of QoS in LTE, heterogeneous LTE-A
networks, and how traffic is classified within a packet scheduling architecture for heterogeneous LTE-A
networks. Then, by summarising the proposed QoS-based packet scheduling algorithms in the literature for
Heterogeneous LTE-A Networks, and for Femtocells LTE-A Networks. And finally, we provide some
concluding remarks in the last section.
QOS-BASED PACKET SCHEDULING ALGORITHMS FOR HETEROGENEOUS LTEADVANCED NETWORKS...
Cellular qos
1. QoS in Cellular Networks
Dushyanth Balasubramanian, Washington University in Saint Louis, dushyanthb@gmail.com
Abstract:
This paper discusses different schemes for providing Quality of Service (QoS) in cellular networks.
Each scheme has its own algorithm to provide QoS and every scheme has its advantages and
disadvantages. I have also dealt about an important aspect of QoS which is the Individual QoS (iQoS).
iQoS measures the satisfaction rate per user and it is measured individually at each and every user
terminal. Voice traffic is very delay sensitive and data traffic is loss sensitive. QoS schemes which try to
incorporate both voice and data have to take into consideration this issue. I have also discussed the
integration of WLAN/cellular networks in which the high data rate of the WLAN network and the high
mobility of cellular networks are utilized effectively.
Back to Raj Jain's Home Page
Table of Contents:
! 1. Introduction: What is QoS
" 1.1 Why do we need QoS
" 1.2 QoS Challenges
" 1.3 What has been achieved so far in QoS
! 2. UMTS QoS Architecture
" 2.1 End - to - End Service and UMTS Bearer Service
" 2.2 The Radio Access Bearer Service and the Core Network Bearer Service
" 2.3 The Radio Bearer Service and the RAN Access Bearer Service
" 2.4 The Backbone Network Service
! 3. UMTS QoS Classes and Attributes
" 3.1 Conversational Class
" 3.2 Streaming Class
" 3.3 Interactive Class
" 3.4 Background Class
" 3.5 QoS Attributes
! 4. DIFFERENT QoS SCHEMES IN CELLULAR NETWORKS
" 4.1 Fault Tolerant Dynamic Channel Allocation Scheme
# 4.1.1 System Model
# 4.1.2 Distributed Channel Allocation Algorithm
" 4.2 Call Admission Control(CAC) Scheme
# 4.2.1 Channel Prioritization Schemes
# 4.2.2 Call Admission Algorithm (CAC)
" 4.3 QoS based on Mobility Prediction Techniques
# 4.3.1 Road Topology based Mobile Prediction Techniques
" 4.4 Dynamic Allocation Scheme using Renegotiation
# 4.4.1 Different Service Classes
# 4.4.2 Renegotiation Scheme
# 4.4.3 Renegotiation by Flow Termination
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2. " 4.5 Individual QoS for Voice Services
# 4.5.1 Purpose of Measuring iQoS
# 4.5.2 Concept of iQoS Rating
! 5 QoS in Cellular/WLAN Networks
" 5.1 Tight Coupled QoS Model Structure
" 5.2 Loosely Coupled Cellular/WLAN interworking Model
# 5.2.1 Call Admission for Voice and Data Traffic
! 6. Summary
! References
! List of Acronyms
1. Introduction: What is QoS
Quality of Service (QoS) in cellular networks is defined as the capability of the cellular service
providers to provide a satisfactory service which includes voice quality, signal strength, low call
blocking and dropping probability, high data rates for multimedia and data applications etc. For network
based services QoS depends on the following factors [ Jain 06 ]
! Throughput The rate at which the packets go through the network. Maximum rate is always
preferred.
! Delay This is the time which a packet takes to travel from one end to the other. Minimum delay is
always preferred.
! Packet Loss Rate The rate at which a packet is lost. This should also be as minimum as possible.
! Packet Error Rate This is the errors which are present in a packet due to corrupted bits. This
should be as minimum as possible
! Reliability The availability of a connection. (Links going up/down).
It is for these reasons that providing QoS has been a great challenge in the past and it continues to be a
hot topic as there is still a lot of scope to provide better service standards.
1.1 Why do we need QoS
Imagine a situation where you are hardly able to hear what your friend is talking over the phone or the
phone gets cut when you are talking something important. These things are highly undesirable and you
do not want to get low quality service for paying high monthly bills. Communication plays a major role
in today's world and to support it QoS has to be given maximum priority. It is important to differentiate
the traffic based on priority level. Some traffic classes should be given higher priority over other classes,
Example: voice should be given a higher priority compared to data traffic as voice is still considered as
the most important service. It should be noted that more preference has to be given to customers who
pay more to get better service, without affecting the remaining customers who pay normal amount. To
realize all these things effective QoS schemes are needed. Issues and schemes related to providing better
QoS is the main subject of this report.
1.2 Quality of Service Challenges
In wireless mobile networks QoS refers to the measurement of a system with good transmission quality,
service availability and minimum delay. In 4G it is expected to have a reliability of at least 99.999
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3. referred to as five nine reliability. The major challenges when considering QoS in cellular networks are
varying rate channel characteristics, bandwidth allocation, fault tolerance levels and handoff support
among heterogeneous wireless networks. It is fortunate that each layer which includes physical, MAC,
IP, TCP and application have got their own mechanisms to provide QoS. It is important to guarantee
QoS in each layer so that the network is more flexible and tolerant to QoS issues. Some of the other
challenges are efficient usage of the spectrum as its availability is limited. Bandwidth allocation plays a
major role with respect to this aspect. It must be made sure that bandwidth is allocated in an efficient
manner and also the remaining bandwidth should not be wasted. Some schemes like Renegotiation
scheme [Monego 05] takes care of this issue by allocating the remaining bandwidth to lower priority
classes. Things get even more complicated when data and voice service has to be supported. Voice
services are very delay sensitive and require real - time service. On the other hand data services are less
delay sensitive but are very sensitive to loss of data and also they expect error free packets. So both
these factors have to be considered for providing QoS for voice and data services.
1.3 What has been achieved so far in QoS
In 1G networks and 2G networks such as GSM and CDMA there was only one aspect of QoS and it is
voice. Providing quality speech was the major concern. Now in 3G networks QoS has to be provided for
voice as well as data. Still priority is given for voice services as they are considered as the primary
service. They are very delay sensitive and require real - time service. Data services are comprised of text
and multimedia. These services are less delay sensitive but expect better throughput and less or no loss
rate.
The rest of this paper is organized as follows. Section 2 talks about the Universal Mobile
Telecommunication System (UMTS) QoS architecture and every layer in the architecture is described
with their functionalities. In Section 3 we deal with different classes of QoS and also the various
attributes which specify the iQoS. Section 4 deals with the various QoS schemes in cellular networks
such as Fault Tolerant Dynamic Channel Allocation, Call Admission Control (CAC) algorithm, QoS
provisioning using mobile prediction techniques to improve hand over loss probability, Dynamic
channel allocation using Renegotiation techniques and iQoS which is an important aspect of QoS from
user's point of view. Section 5 discusses about the coupling of WLAN and cellular networks so that the
high data rate of the WLAN and the high mobility of the cellular networks is utilized. Two different
architectures loosely coupled approach and tightly coupled approach are considered and explained.
Finally Section 6 summarizes the whole report. List of Acronyms and References are given towards the
end.
Back to Table of Contents
2. UMTS QoS Architecture [ 3GPP 23.107 ]
Overview of Different Levels of QoS
An end - to - end service implies that the communication takes place from one Terminal Equipment
(TE) to another. The user of the network service is provided with a QoS and it is the user who decides
whether he is content with the QoS or not. A bearer service with clearly specified characteristics and
functionalities is to be set up from source to destination to meet the network QoS requirement. The
architecture of UMTS bearer service is a layered one as shown in figure 1. Bearer services provide QoS
based on services provided by the layers below them.
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4. Figure 1: UMTS QoS Architecture [ 3GPP 23.107 ]
2.1 End - to - End Service and UMTS Bearer Service [ 3GPP 23.107 ]
As shown in the figure 1 the End - to - End service layer is the topmost layer of the QoS architecture. It
makes communication possible from one TE to the other. It is shown that a TE is connected to the
UMTS network by means of a Mobile Termination (MT). The End - to - End services used by a TE will
be realized by the below layers namely TE/MT local bearer service, a UMTS bearer service and external
bearer service. The UMTS operator offers services provided by the UMTS bearer service. Thus UMTS
bearer service provides the UMTS QoS.
2.2 The Radio Access Bearer Service and the Core Network Bearer Service [ 3GPP
23.107 ]
The UMTS Bearer service is comprised of two parts which are the Radio Access Bearer Service and the
Core Network Bearer Service. Both these services take care of the Bearer service over the network
topology taking into consideration attributes such as mobility and mobile subscriber profiles. The Radio
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5. Access Bearer Service makes provision for the transport of signaling and user date between MT and CN
Edge Node with QoS adequate to the negotiated UMTS bearer service or with default QoS for signaling.
Radio Bearer Services provides the unequal error protection if that feature has to be supported.
The Core Network Bearer Service of the UMTS core network connects the UMTS CN Edge Node with
the CN Gateway to the external network. This service controls and utilizes the backbone network
efficiently in order to provide the contracted UMTS bearer service. [ 3GPP 23.107 ]
2.3 The Radio Bearer Service and the RAN Access Bearer Service [ 3GPP 23.107 ]
The Radio Access Bearer Service is realized by a Radio Bearer Service and an RAN Access - Bearer
Service. The Radio Bearer Service covers all the aspects of the radio interface transport. [ 3GPP 23.107 ]
To support unequal error protection, RAN and MT has the ability to segment/reassemble the user flows
into the different subflows requested by the Radio Access Bearer Service. The segmentation/reassemble
is given by the Service Data Unit (SDU) payload format signaled at Radio Access Bearer establishment.
[ 3GPP 23.107 ]
2.4 The Backbone Network Service [ 3GPP 23.107 ]
The core Network Bearer Service uses a generic Backbone Network Service. The Backbone Network
Service covers the layer 1/layer 2 functionality and is selected according to the operator's choice in order
to fulfill the QoS requirements of the CN Bearer Service. [ 3GPP 23.107 ]
Back to Table of Contents
3. UMTS QoS Classes and Attributes [ 3GPP 23.107 ]
There are four different QoS classes:
! Conversational class;
! Streaming class;
! Interactive class;
! Background class
The main differences between these QoS classes are how delay sensitive the traffic is. Conversational
class is meant for traffic which is very delay sensitive while the Background class is the most delay
insensitive class.
Conversational and Streaming classes are used to serve real - time traffic flows which are very sensitive
to the delay. Examples of Conversational classes include real - time services like video telephony and
data streams.
Interactive class and the Background are mainly meant for applications like WWW, Email, FTP, News
and Telnet. Since these classes are less delay sensitive compared to the conversational and streaming
classes, both the classes provide better error rate by means of channel coding techniques and
retransmissions. This means that packet retransmission is done whenever packet error/packet loss/packet
order mismatch takes place. The reason is that these classes are delay insensitive but expect high
throughput and less error rates. The main difference between Interactive and Background class is that
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6. Interactive class is mainly used for interactive applications like interactive Email and interactive Web
browsing, while Background class is meant for background traffic, e.g. background downloads or
Emails and background file downloading. [ 3GPP 23.107 ] The scheduling algorithm gives more priority
to the interactive class than the background class. Therefore the background applications use the
transmission resources only when the interactive applications do not need them.
Table 1: Traffic Classes [ 3GPP 23.107 ]
3.1. Conversational class
Applications which use this class include telephony speech, voice over IP and video conferencing. Real
time conversation is always performed between groups of humans and so this is the only scheme where
the required characteristics are strictly given by human perception. [ 3GPP 23.107 ]
Real time conversation scheme is characterized by that the transfer time should be low because of the
conversational nature of the scheme and at the same time the time variation between information entities
in the stream should be preserved in the same way as for real time streams. [ 3GPP 23.107 ] The
maximum transfer delay is dictated by how much delay the humans can tolerate for audio and video.
Therefore the bounds for acceptable transfer delay are very stringent, and if transfer delay is not low
enough then it affects the quality. The transfer delay should be lower and stringent than the round trip
delay for this class.
3.2. Streaming class
Applications for this class includes listening to or looking at real time video (audio). This scheme is
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7. characterized by that the time relations (variations) between information entities (i.e. sample packets)
within a flow shall be preserved, although it does not have any requirements on low transfer delay.
[ 3GPP 23.107 ] The delay variation of the end - to - end flow should be limited to preserve the time
variation between the information entities of the stream.
3.3.Interactive class
Applications for this class includes browsing the web, database retrieval, access of server etc. Interactive
traffic is a communication scheme which is characterized by the request response pattern of the end
user. Round trip delay is the most important attribute for this class. Another important attribute is that
the error rate should be very low in the data transfer. [ 3GPP 23.107 ]
3.4. Background class
This is a service class in which the applications run in the background. Example includes an email
program which is running in the background. It sleeps for most of the time and wakes up when an email
arrives. Other examples include SMS, download of databases. Background traffic is characterized by
that the destination is not expecting the data within a certain time. Thus this class is less delay sensitive
and another characteristic is that the contents should be delivered with low error rate. [ 3GPP 23.107 ]
3.5. QoS Attributes
UMTS bearer service attributes describe the service provided by the UMTS network to the user of the
UMTS bearer service. A set of QoS attributes (QoS profile) specifies this service. [ 3GPP 23.107 ]
Below is a list of attributes.
Maximum bit rate (kbps) is defined as the maximum number of bits delivered by the UMTS and to the
UMTS at a Service Access Point (SAP) within a period of time, divided by the duration of the period.
The maximum bit rate is the upper limit a user or application can accept or provide. [ 3GPP 23.107 ] The
purpose of this attribute is (1) to limit the delivered bit rate to applications or external networks with
such limitation and (2) to allow maximum waned user bit rate to be defined for applications able to
operate with different rates.
Guaranteed bit rate (kbps) is defined as the guaranteed number of bits delivered by UMTS at a SAP
within a period of time (provided that there is data to deliver), divided by the duration of the period. The
purpose of this attribute is that it describes the bit rate the UMTS bearer service shall guarantee to the
user or application. [ 3GPP 23.107 ]
Delivery order (y/n) indicates whether the UMTS bearer shall provide in - sequence SDU delivery or
not. The purpose of this attribute is to know whether out- of - sequence SDU is allowed or not. [ 3GPP
23.107 ]
Maximum SDU size (octets): is defined as the maximum SDU size for which the network shall satisfy
the negotiated QoS. The purpose of this attribute is that it is used for admission control and policing and
optimizing transport. [ 3GPP 23.107 ]
SDU format information (bits) defines the list of possible exact sizes of SDUs. [ 3GPP 23.107 ]
SDU error ratio: indicates the fraction of SDUs lost or detected as error packets. SDU error ratio is
defined only for conforming traffic. The purpose of this attribute is that it is used to configure the
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8. protocols, algorithms and error detection scheme. [ 3GPP 23.107 ]
Residual bit error ratio: indicates the undetected bit error ratio in the delivered SDUs. If no error
detection is requested, Residual bit error ratio indicates the bit error ratio in the delivered SDUs. The
purpose is that it is used to configure radio interface protocols, algorithms and error detection coding.
[ 3GPP 23.107 ]
Delivery of erroneous SDUs (y/n) indicates whether SDUs detected as erroneous should be delivered
or discarded. This is used to decide whether error detection is required or not and also whether frames
detected as errors should be thrown or not. [ 3GPP 23.107 ]
Transfer delay (ms) is defined as the maximum delay for 95th percentile of the distribution of delay for
all delivered SDUs during the lifetime of a bearer service, where delay for an SDU is defined as the time
from request to transfer and SDU at one SAP to its delivery at the other SAP [ 3GPP 23.107 ]
Traffic handing priority specifies the relative importance of handling of all SDUs belonging to the
UMTS bearer compared to the SDUs of other bearers. [ 3GPP 23.107 ]
Back to Table of Contents
4. Different QoS Schemes In Cellular Networks
There are many QoS schemes which have been deployed for cellular networks and each scheme has its
own advantages and disadvantages. In this section we are going to look into some of the fundamental
and effective QoS schemes which are used for providing voice and data services. Fault Tolerant
Dynamic Allocation scheme looks into methods of reusing the channels effectively between two cells,
which are separated by a minimum distance so that they do not interfere with each other. The channels
are allocated dynamically as opposed to static allocation where the channels are allocated and reserved
beforehand. [Yang 03] The next scheme is the Call Admission Control (CAC) which employs pre -
blocking of calls based on the available bandwidth for handling calls. This algorithm is based on two
schemes which were used earlier namely Pre request scheme and the guard channel scheme. CAC
algorithm utilizes both the schemes and gives better performance in terms of successful call completion
rates (SCCR) and provides guaranteed QoS for profiled users. [Kovvuri 2003] In the Mobility prediction
techniques hand off losses are reduced and due to which the blocking and the dropping probabilities are
significantly reduced. In this mobility prediction scheme road topology information is gathered and
stored in a database and the path or the trajectory of the mobile host is calculated. No assumption about
the shape of the cell is assumed. [Soh 03] The renegotiation scheme is a scheme in which the bandwidth
allocation is changed dynamically based on the availability. If a low priority service has been admitted
with a bandwidth less than what it had asked and after sometime extra bandwidth is available due to
completion of a high priority service then the remaining bandwidth is given to the low priority service
and thus increases the QoS of the lower priority service. This scheme also ensures that the higher
priority services get their requested bandwidth and they are not affected in any way. [Monego 05]
4.1 Fault Tolerant Dynamic Channel Allocation Scheme [Yang 2003]
In this scheme the channels are allocated dynamically based on demand and hence increasing the
channel utilization and also the QoS. The channel allocation schemes are centralized and distributed. In
a centralized approach there is a central controller which is responsible for channel allocation and
requests are sent to the controller, whereas in a distributed approach there exists a Mobile Service
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9. Station (MSS) in each cell which takes care of the channel allocation for that particular cell. Distributed
approach is more scalable and reliable and thus this approach is used in this algorithm.
Figure 2: A Model of Wireless Communication Networks [Yang 03]
Figure 2 shows the model of wireless communication. There are many cells which are comprised of
many Mobile Hosts (MH) and a Mobile Service Station (MSS). The cells are connected to a fixed
network. Each MH when it wants to communicate with another mobile host has to request a channel
from MSS for communication. There are two types of channels namely communication channel and
control channel. A communication channel is used to support communication between a MH and a MSS
whereas control channels are used for sending control messages like MH requesting the MSS to set a
communication channel by means of a control channel. The MSS allocates channels to the MH based on
whether co - channel interference occurs. If there is no such interference then it allocates the channel to
the MH for communication.
There two different approaches for requesting channels. In Centralized approach each MH requests for
channels from a central controller called Mobile Switching Center (MSC). So the channel allocation is
done by MSC in such a way that no co - channel interference takes place. The disadvantage of this
approach is that the MSC can become a bottleneck in the network and the failure of the MSC means the
whole network is affected. Thus this approach is not at all scalable and robust.
In the Distributed approach there is no central controller and each cell has its own MSS. It is the job of
the MSS to allocate channels and it makes sure that no channel interference occurs. In this approach a
cell updates its neighbors about its usage of channels and lets them know when it relinquishes any
channel so that others can use it. When a cell wants a channel it sends a request message to all its
neighbors and when it gets reply from all of its neighbors that a channel can be used, then it uses that
channel.
4.1.1 System Model [Yang 2003]
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10. In this section we talk about the system model of this distributed fault tolerant approach. Channels are
allocated dynamically and not allocated in advance to any cells. A three cell cluster model is used and
each cell has got six neighbors. If a channel is used by one particular cell then none of its neighbors can
use the same channel and thus prevents co - channel interference. A cell can borrow a channel to use if it
does not have any channel for communication. The request is to be satisfied by any of the cell's
neighbors who can lend a channel and also making sure that co - channel interference does nor occur.
There are two modes of operation which are update mode and search mode. In an update mode a cell
informs its channel usage information to all its neighbors whenever it borrows or releases a channel.
Thus it updates all the neighbors about the status. In a search mode, when a cell needs to borrow a
channel it sends request message to all of its neighbors. Based on the reply it gets from the neighbors it
borrows a channel.
4.1.2 Distributed Channel Allocation Algorithm [Yang 2003]
In this model a three cell cluster model is there and each cell has six neighbors and each of them have a
unique neighbor id ordered from one to six. Channels are not pre-allocated to any cell. The channel with
lowest frequency has the minimum order and the channel with highest frequency has the maximum
order. A cell Ci selects a channel with the highest order to support a call if it is available.
Figure 3: Cell Cluster Model to Illustrate Distributed Channel Allocation [Yang 03]
In figure 3 each cell is numbered from 1 to 6 and we are going to use cell Ci to represent a particular
cell. When Ci requests for a channel to use it is in search mode and it's called a borrower. It sends a
broadcast message to all its neighbors for the channel and sets a timer and waits till the timer times out.
When a cell is in borrower mode it does not respond to any query from any other cell requesting
channels. This is because the borrower itself is in search for channels and so it's not going to be of any
help to other channels which are requesting. This scheme is nice in the way that it prevents unnecessary
congestion in the network. Now after the timer times out, the cell Ci will borrow a channel based on the
replies which it got from its neighbors.
To prove that this algorithm works lets assume that the cell Ci has got replies only from 2 neighbors, 1
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11. and 4 and there is a channel r which is allocated to both the cells 1 and 4. In this case the cell Ci can
borrow the channel r even though other cells (2,3,5,6) have not replied other than cells 1 and 4. The
reason is that since channel r is allocated to cells 1 and 4, it cannot be allocated to the neighbors of cells
1 and 4 (cells 2, 6, 3 and 5) due to co - channel interference. Thus channel Ci can borrow the channel
with the replies it got from just two channels. This proves that this algorithm is fault tolerant.
Thus the above algorithm which we saw was fault tolerant as it need not wait for replies from all the
channels. This also means that the algorithm is more scalable. It uses distributed channel allocation
scheme in which channels are allocated dynamically based on request. This algorithm also allows reuse
of channels. This means that a lender can lend a channel to two or more cells simultaneously provided
that no co - channel interference occurs.
4.2 Call Admission Control (CAC) Scheme [Kovvuri 2003]
In the CAC algorithm new call arrival rates are estimated continuously and if they are higher than a
predetermined level some calls are blocked irrespective of whether a channel is available or not. The
objective of this scheme is to maintain the new call arrival rate lesser than a predetermined level. In this
scheme a comparison is made with the existing two schemes namely prerequest scheme and the guard
channel scheme and various advantages and disadvantages are given for the two schemes and then a
CAC algorithm is developed which provides a better QoS than the existing two schemes. The two
metrics used for QoS in this algorithm are Forced Termination Probability (FTP) which is defined as the
ratio of the number of calls which are forced to terminate because of failed handoff to the number of
calls that successfully entered the network. Another metric is the Successful Call Completion Rate
(SCCR) which is defined as the number of calls which are completed successfully in a unit time by each
cell. [Kovvuri 03] So lower FTP and higher SCCR is what ideal algorithms will try to achieve and this
algorithm achieves that.
4.2.1 Channel Prioritization Schemes
In the Guard Channel Scheme some channels are exclusively reserved for the handoff calls and these
channels are called guard channels. A certain number of channels say G out of C channels are
exclusively reserved for handoff calls of the profiled users. The remaining channels are shared for all
types of calls. These calls include new calls, handoff calls of profiled users and handoff calls of non
profiled users. This is an example of static allocation of channels.
In the channel prerequest scheme the channels are requested beforehand before the handoff occurs. The
information about the mobility patterns of the profiled users is in the Home Location Register (HLR)
and using this information the handoff behavior of the profiled users can be predicted. The prerequest
channels are requested from the neighboring cell for a certain amount of time called as the reservation
period. By increasing the reservation period the probability of forced termination can be significantly
reduced.
4.2.2 Call Admission Algorithm (CAC)
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12. Figure 4: Flow Chart for CAC Algorithm [Kovvuri 03]
In the CAC algorithm the acceptable load is calculated based on simulation results and this value is used
for comparison purpose. The estimated load is also calculated and it is checked with the acceptable load.
If the estimated load is lesser than or equal to the acceptable load, then attempts are made to allocate
channels for all the incoming calls. If the estimated load is greater than the acceptable load then only a
fraction of the incoming calls will be allocated channels and the remaining fraction of the calls will be
discarded even if there are available channels. This is called pre - blocking of channels and this scheme
improves the FTP and SCCR of the profiled users.
4.3 QoS based on Mobility Prediction Techniques [Soh 2003]
Mobile prediction techniques are employed to find the path or the trajectory of a mobile node and it is
stored in a database from time to time. This technique helps in reserving resources for MH before a hand
off occurs so prioritizing resources takes place for a node before its hand off and thus this decreases the
call blocking rate at hand offs. However the new call admission rate is reduced as more resources are
reserved for hand off calls. Forced termination can be reduced by increasing the number of new call
blocking probability. But this is not very efficient utilization of the radio resources. By using mobile
prediction techniques, we can know in advance when a handoff will take place and so dynamic
allocation of resources for the handoff can be done. This ensures that the new call blocking probability is
not increased so much to preserve resources for the hand off calls. There are many mobile prediction
techniques which have been employed in the past which includes GPS positioning methods in which
each MH is integrated with a GPS receiver so that the path of the MH can be traced.
4.3.1 Road Topology based Mobile Prediction Techniques [Soh 2003]
This technique is based on the fact that MH's in vehicles will encounter the most frequent hand offs and
so studying their characteristics would prove to be more beneficial. Since the vehicles travel on the road,
the road topology is studied and is used in the prediction algorithm. In this scheme the base station will
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13. do the mobile prediction based on the road topology information it has. Since the base station has more
storage capability and resources than the MH, it is used for better accuracy.
Figure 5: Road Topology Information for Mobility Prediction [Soh 03]
In this technique there are several base stations, which are updated with the MH's latest position at
regular interval of time. Each base station will maintain a database which contains information about the
road topology. As shown in figure 5 the road which consists of bends are broken into many piecewise
linear line segments and the coordinates for these line segments are stored separately. The database has
information such as average time to transit a segment, neighboring segments at each junction and the
probability of the MH to do an hand off and go to a next neighboring segment. The database is updated
periodically and at every instant the information about the location of the MH is obtained. Segments
which have already had hand offs are referred to as handoff probable segments. Using this model,
accurate prediction is done, which is useful in prioritizing resources for the handoff of an MH.
4.4 Dynamic Allocation Scheme using Renegotiation [Monego 05]
In a Dynamic Allocation scheme using Renegotiation, the unused resources of the network are explored
and they are allocated to services which got a lesser bandwidth at the time of admission when they
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14. actually wanted more. In other words, renegotiation of the bandwidth is done for a lower priority service
when the medium is free, thus increasing the overall bandwidth of the lower priority services. The
scheme on the other hand also maintains the bandwidth of the higher priority sources.
4.4.1 Different Service Classes
Conversational and streaming classes are associated with real time traffic and are extremely delay
sensitive. Examples of these kinds of services are video telephony, telnet, voice and video. On the other
hand Interactive and background processes are less delay sensitive and they include applications like
FTP, WWW, email and news. Since they are less sensitive to delay both these classes provide better
error rates by using channel coding techniques. The difference between the interactive and the
background services are that interactive services are mainly used by interactive applications like for
example, interactive email. Background classes are used for background applications which include
background browsing and background emails.
4.4.2 Renegotiation Scheme [Monego 05]
In this scheme the conversational classes are given the maximum priority and they are priority 1 class.
The streaming class is also given high priority and it belongs to priority 2 classes. Now these priority 1
and priority 2 classes will be admitted only if there is enough resources (bandwidth) to satisfy their
requirements. If not their requests won't be admitted. The interactive service is given the lowest priority
and it is 3. So the request from these classes are admitted even if the network have a lesser bandwidth
than what they had requested. The advantage of the Renegotiation scheme when compared to the CAC
scheme is that in the CAC scheme when a bandwidth is allocated to priority 1 and 2 they cannot be
transferred to a lower priority class even after the higher priority class leaves the network. In
renegotiation scheme a priority 3 application can use more bandwidth that what was allocated for it.
This is made possible because any unused resources by the higher priority classes can be transferred to
this class. On the other hand when a high priority class arrives again it will not be blocked if the system
has low resources. At that time the bandwidth given to a lower priority class will be taken back and will
be allocated to the high priority class. Thus the higher priority class is not harmed in any way.
4.4.3 Renegotiation by Flow Termination [Monego 05]
The renegotiation by flow termination is a means by which more bandwidth is allocated for a low
priority flow when a high priority flow ends or when there are more resources available in the network.
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15. Figure 6: Behavior of Two Flows Without (a) and With (b) Renegotiation [Monego 05]
In figure 6 behavior of two different flows are shown without and with renegotiation. In case (a) without
renegotiation the bandwidths of A and B are shown. Even after the termination of flow A the bandwidth
of B remains the same. In case (b) after the termination of flow A the bandwidth of flow B is increased
due to the availability of resources.
4.5 Individual QoS for Voice Services [Medeisis 04]
The Individual QoS is a very important measurement of QoS and its value is often overlooked. So far
QoS based on cell or network level is what is done in all the QoS studies. Individual QoS (iQoS)
measures the satisfaction rate per user and that is one of the most important parameters which has to be
considered. It is done individually at each and every user terminal. The estimation of overall QoS in the
network does not give a very accurate picture of what each and every individual user is encountering.
For Example the average rate of dropped calls in the whole network may be as low as 1 - 2 percent.
However, some users may experience much more frequent dropped calls, probably 30% of their calls
may be dropped. This means that the overall network level QoS is high (more than 95 percent) but some
users have become victims of this average process and they are charged by their network operators for
the QoS which they actually did not receive. It turns out that users in area with very less radio coverage
often experience this kind of loss then the average cannot be taken into account for those users and their
dissatisfaction is hidden in the average. Thus it is very important to measure each users satisfaction in a
network.
4.5.1 Purpose of Measuring iQoS [Medeisis 04]
It may be observed that whatever global QoS management concept is realized in a network by definition
it can never produce the same amount of user level satisfaction. The radio strength which a user gets
depends on his physical position with respect to the base station. For users who are very much near the
base station, they might get very good signal strength and voice quality but for users who are very far
away from the base station may experience a very poor network connection and also lots of dropped
calls. The median signal level characterization of radio link budget for particular point may be easily
vary by some 10 - 20 dB just within a short distance of few tens of meters. Thus it will be much better if
iQoS is included in the billing so that every individual user is aware of what QoS he is getting and he
knows whether he gets the quality for what he is paying. [Medeisis 04]
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16. 4.5.2 Concept of iQoS Rating [Medeisis 04]
It is evident that in the users perspective setup failure and drop call will be the most annoying thing as
he will have to pay for the services not received if error occurs after the billing timing is triggered. So
for measuring iQoS first of all differentiation of users who have not received a dropped call versus users
who have received dropped call should be made. The Quality of service should be measured for only
those people who experience bad service like dropped calls and call blocking.
Back to Table of Contents
5 QoS in Cellular/WLAN Networks [Begain 04] [Song 05]
Wireless LAN (WLAN) systems provide very high data rate but less mobility and on the other hand
cellular networks provide a very high mobility but not high data rate. So a combination of both these
networks will result in a network with a very high data rate as well as mobility. It is using this idea that
people tried to combine both the WLAN and Cellular networks and it has proved to provide good data
rate as well as mobility. The issue to be considered here is that the QoS of cellular networks is well
defined and it is much easier to provide compared to the QoS in the IP network. There is no assured QoS
in the IP network and hence when combining both these networks we will have QoS issues which needs
to be solved and its much difficult to manage QoS in Integrated Networks.
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17. Figure 7: Loose Coupling (a) and Tight Coupling (b) [Begain 04]
In Tight coupling the WLAN technology is employed as a new radio access technology within the
cellular system. Regardless of the access technology there will be one common cellular core networks.
This can be done by connecting WLAN AP to a radio network controller (RNC). Loose coupling on the
other hand is less connection between the two networks. In this scenario WLAN and the cellular
networks are two separate access networks. The WLAN access network is attached to the Internet
backbone and the cellular network into the cellular core network. [Begain 04]
5.1 Tight Coupled QoS Model Structure [Begain 04]
In this Tight coupled architecture the cellular network is based on an IP based packet switching network.
This architecture assumes a packet switching core network based on UMTS network architecture.
[Begain 04] Figure 8 shows the components of this tightly coupled architecture.
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18. Figure 8: Tightly Coupled QoS Model Architecture [Begain 04]
A Policy Provisioning Module (PPM) The PPM takes the users QoS and decides which class the
traffic belongs to (priority level) and then it handles the users request to the Connection Admission
Control Module (CAC) for further processing of the request as to allow the traffic or not.
A Connection Admission Control Module (CAC) The CAC modules accepts the traffic flows and
allots bandwidth to all the flows. It can also reject flows if there is no available bandwidth for a
particular flow. It also maintains the QoS of the already existing connections. The CAC module first
receives a connection request from the PPM and then it consults the Mobility Management Module
(MMM) to know about the mobility status and the information about nodes. It then uses reservation
protocols such as RSVP to reserve connections.
A QoS Mobility Management Module (MMM) MMM monitors the terminals which are no longer
connected to the network, idle terminals and the terminals which are connected to the network. It also
monitors the connected nodes which are mobile at high speeds. Issues such as handover between a
cellular to WLAN and WLAN to cellular networks are taken care by this module. Another important
aspect of the MMM is that it monitors the QoS of the users and if the QoS profile is not satisfied then it
has a feedback mechanism in which the it informs the CAC about the current QoS of the user and
triggers more action for improvement of the QoS.
5.2 Loosely Coupled Cellular/WLAN interworking Model [Song 05]
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19. In this loosely coupled architecture there is no direct link between the WLAN and the cellular networks.
The gateway connects the WLANs to the Internet backbone. The advantage of this approach is that there
is not dependency between the two networks. Each one can be deployed independently and one network
wont be a bottleneck to the other. An all IP DiffServ platform is the most popular architecture for this
loosely coupled scheme and we are going to look into this architecture.
Figure 9: Loosely Coupled cellular/WLAN Architecture in a DiffServ Platform [Song 05]
Figure 9 shows the loosely coupled cellular/WLAN architecture in a DiffServ platform. This illustrates
the integration of WLAN with different cellular architectures such as UMTS, code division multiple
access (cdma2000) and GSM/GPRS. The DiffServ platform is a domain based architecture in which
different domains can freely choose their own system mechanisms and it should ensure that the service
level agreements (SLAs) with neighboring domains are satisfied.
5.2.1 Call Admission for Voice and Data Traffic
The two most important services voice and data are considered in this section. Voice traffic is delay
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20. sensitive and requires real - time transmission. It can tolerate some data losses. On the other hand data
traffic is not so delay sensitive but they are very sensitive to packet loss and error rates. Voice calls are
always given priority over data traffic in cellular networks, as voice calls are more delay sensitive and
also cellular networks provide better QoS which is needed for voice services. On the other hand data
traffic will most likely end in WLAN coverage as it gets better bandwidth in that region.
Figure 10: Call admission procedure for cellular/WLAN interworking [Song 05]
Figure 10 explains in detail the Call admission procedure for cellular/WLAN networks. An area with
only cellular coverage is called as cellular - only area and an area with WLAN and cellular coverage is
called double - coverage area. For voice calls, it has got two choices. It can either try cellular area or
WLAN coverage area. If a voice call is rejected in a cellular coverage area the it tries in WLAN area.
The request is rejected if there is not enough bandwidth to accommodate the voice call in this area. A
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21. data call has only one option which is the WLAN area. If it is rejected there it wont try the cellular area
as the data traffic overflow in cellular area will degrade the QoS of voice traffic. To provide a priority to
voice calls in cellular - only area limited fractional guard channel (LFG) policy is used. [Song 05]
Back to Table of Contents
6 Summary
Quality of Service plays a major role in cellular networks. In this report we have seen the various
schemes for maintaining the QoS in cellular networks and each scheme has its own advantages and
disadvantages. The Dynamic channel allocation scheme is fault tolerant and it provided a way to reuse
the channels and also there was no need to get response from every neighbor for borrowing a channel.
Therefore this scheme reduces the overall congestion in the network.
The CAC algorithm combined the advantages of two schemes namely pre request and the guard channel
scheme and it proved to be much better than both these schemes for providing a better QoS for profiled
users. In this techniques there was a pre - blocking feature where if the estimated load is greater than the
accepted load then some fraction of the calls will be blocked even if there is channel for them.
In the Renegotiation scheme it was proved that when a lower priority class is admitted with a lesser
bandwidth than what they had requested, they are given a much higher bandwidth when there was
unused resources by the higher class services. On the other hand this scheme also guarantees the higher
class services the bandwidth they are supposed to get. Thus it improves the overall QoS of the lower
class services without affecting the higher class services.
It was also seen that iQoS was a very important parameter which has to be considered. It measures the
overall user satisfaction for the full duration of the call and that is more important as some users QoS is
buried in the averaging policy and so the real truth about users QoS is found by this technique. It was
also seen that users who were not close to the BS were not getting good signal and the location of the
users played a major role.
Finally we saw the integration of both WLAN and cellular networks and this is a scheme where in the
mobility of the cellular network and the high data rate of the WLAN network are combined to provide
an integrated network with high data rate for the users as well as good mobility. Issues such as QoS in IP
is not assured and that is a major issue in this integrated network. Two different architectures namely
Tight coupled and loosely coupled architecture were discussed. In a tight coupled scheme the WLAN
technology is employed as a new radio access technology within the cellular system. The disadvantage
of this scheme is that it is not scalable. In a loosely coupled architecture there is no direct link between
the WLAN and the cellular networks. The advantage being that each network can be deployed
independently and there is no bottleneck. The disadvantage is that it is difficult to guarantee end - to -
end QoS.
Back to Table of Contents
References
[3GPP 23.107] 3GPP 23.107 V7.4.0,"Quality of Service (QoS) Concept and Architecture," June 2006
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22. http://www.3gpp.org/ftp/Specs/html-info/23107.htm
[3GPP 23.207] 3GPP 23.207 V6.6.0,"End - to -End Quality of Service (QoS) Concept and
Architecture," June 2006 http://www.3gpp.org/ftp/Specs/html-info/23207.htm
[Jain 06] Lecture Notes of Prof. Raj Jain in QoS, Apr 2006 http://www.cse.wustl.edu/~jain/cse574-
06/j_9qos.htm
[Yang 03] Jianchang Yang, D.Manivannan and Mukesh Singhal, "A Fault Tolerant Dynamic Channel
Allocation Scheme for Enhancing QoS in Cellular Networks,"
http://ieeexplore.ieee.org/iel5/8360/26341/01174857.pdf?tp=&arnumber=1174857&isnumber=26341
[Kovvuri1 03] Satya Kovvuri1, Vijoy Pandey2, Dipak Ghosal2, Biswanath Mukherjee2 and Dilip
Sarkar1, "A Call-Admission Control (CAC) Algorithm for Providing Guaranteed QoS in Cellular
Networks," http://www.springerlink.com/(rpophtf1vxmipbab1vtfyv45)/app/home/main.asp?
referrer=default
[Soh 03] Wee-Seng Soh and Hyong S. Kim, "QoS Provisioning in Cellular Networks Based on Mobility
Prediction Techniques," http://ieeexplore.ieee.org/iel5/35/26307/01166661.pdf?
tp=&arnumber=1166661&isnumber=26307
[Monego 05] Hermes Irineu Del Monego1, Eliane Lucia Bodanese2, Luiz Nacamura Jr1, and Richard
Demo Souza1, "A Dynamic Resource Allocation Scheme for Providing QoS in Packet-Switched
Cellular Networks," http://springerlink.metapress.com/
(xxolql45nijqxu55b4eq5345)/app/home/main.asp?referrer=default
[Medeisis 04] Kajackas A., Batkauskas V., Medeisis A , "Individual QoS Rating for Voice Services in
Cellular Networks," http://ieeexplore.ieee.org/iel5/35/28971/01304238.pdf?
tp=&arnumber=1304238&isnumber=28971
[Begain 04] Xin Gang Wang, John Mellor and Khalid Al-Begain, "Towards Providing QoS for
Integrated Cellular and WLAN Networks," http://www.cms.livjm.ac.uk/pgnet2003/submissions/Paper-
23.pdf
[Song 05] Wei Song, Hai Jiang, Weihua Zhuang, and Xuemin (Sherman) Shen, "Resource Management
for QoS Support in Cellular/WLAN Inter working,"
http://ieeexplore.ieee.org/iel5/65/32333/01509947.pdf?tp=&arnumber=1509947&isnumber=32333
[Cotanis 03] Nicolae Cotanis, "QoS Estimation for Cellular Packet Data Networks,"
http://www.lcc.com/ABOUT/MEDIA/QoS%20Estimation%20for%20Cellular%20Packet%20Data%
20Networks.doc.pdf
[Jain 01] "Issues in Emerging 4G Wireless Networks,"
http://www.ee.oulu.fi/~skidi/teaching/mobile_and_ubiquitous_multimedia_2002/issues_in_emerging_4G
[Sadeghi 04] Bahareh Sadeghi and Edward Knightly, "Architecture and Algorithms for Scalable Mobile
Qos," http://portal.acm.org/citation.cfm?
id=602414&coll=portal&dl=ACM&CFID=70683969&CFTOKEN=41794812&ret=1#Fulltext
[Nokia] "Multiplayer Game Performance over Cellular Networks v1.0"
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23. http://www.forum.nokia.com/info/sw.nokia.com/id/b2b3781e-3dce-42dc-9e75-
110e76b3e784/Multiplayer_Game_Performance_over_Cellular_Networks_v1_0_en.pdf.html
[Wu 03] "2.5G/3G Quality of Service - What has been Achieved so Far,"
http://www.touchbriefings.com/pdf/20/wire02_t_Ascom.pdf
[Yu 04] Fei Yu, Vincent W.S Wong and Victor C.M Leung, "A New QoS Provisioning Method for
Adaptive Multimedia in Cellular Wireless Networks," http://www.ieee-
infocom.org/2004/Papers/44_1.PDF
[Rachidi 05] T. Rachidi, M. Sebbane, A.Y. Elbatji and H. Bouzekri , "An Integrated System for QoS
Provisioning in 3G WCDMA Cellular Networks,"
http://www.ctr.kcl.ac.uk/mwcn2005/Paper/C200516.pdf
"QoS in Integrated 3G Networks by Robert Lloyd-Evans, Artech House,2002"
Service Performance and Optimization in 2G/3G Networks: Providing End to End Quality of Service
edited by Gerardo Gomez, Rafael Sanchez , John Wiley and Sons ,2005
End-to-End Quality of Service over Cellular Networks : Data Services Performance Optimization in
2G/3G by Gerardo Gomez and Rafael Sanchez (Hardcover - May 31, 2005),John Wiley & Sons
QoS in Integrated 3G Networks (Hardcover) by Robert Lloyd-Evans, 2002
Back to Table of Contents
List of Acronyms
3G- 3rd Generation
3GPP- 3rd Generation Partnership Project
CAC- Call Admission Control
DiffServ- Differentiated Service
iQoS- Individual QoS
IntServ- Integrated Service
FTP- Forced Termination Probability
GPS - Global Positioning System
HLR- Home Location Register
km- Kilometer
LAN- Local Area Networks
LFG- Limited Fractional Guard Channel
MAC- Medium Access Control
MH- Mobile Host
MMM- Mobility Management Module
MPLS-Multi-Protocol Label Switching
MSC- Mobile Switching Center
MSS- Mobile Service Station
MT - Mobile Terminal
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24. MAN- Metropolitan Area Networks
Mb/s - Mega bits per second
PPM- Policy Provisioning Module
QoS- Quality of Service
RNC- Radio Network Controller
SAP- Service Access Point
SCCR- Successful Call Completion Rate
SDU- Service Data Unit
SLA- Service Level Agreements
TE- Terminal Equipment
UMTS- Universal Mobile Telecommunication System
WAN- Wide Area Networks
WLAN- Wireless Local Area Networks
Back to Table of Contents
Last Modified on Apr 20,2006 by Dushyanth Balasubramanian
Note: This paper is available on-line at http://www.cse.wustl.edu/~jain
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