26-03-2014, 02:17 PM
4G TEHNOLOGY-A SENSATION
[attachment=60471]
Abstract
This paper describes an architecture for differentiation of Quality of Service in heterogeneous wireless-wired networks. This architecture applies an “all-IP” paradigm, with embedded mobility of users. The architecture allows for multiple types of access networks, and enables user roaming between different operator domains. The overall 4G architecture discussed in this paper is IPv6-based, supporting seamless mobility between different access technologies. Mobility is a substantial problem in such environment, because inter-technology handovers have to be supported. In our case, we targeted Ethernet (802.3) for wired access; Wi-Fi (802.11b) for wireless LAN access; and W-CDMA - the radio interface of UMTS - for cellular access.The architecture is able to provide quality of service per-user and per-service An integrated service and resource management approach is presented based on the cooperative association between Quality of Service Brokers and Authentication, Authorisation, Accounting and Charging systems. The different phases of QoS-operation are discussed. The overall QoS concepts are presented with some relevant enhancements that address specifically voice services. In particular, EF simulations results are discussed in this context.
INTRODUCTION
WIRELESS COMMUNICATION:
A wireless network is an infrastructure for communication “through the air”, in other words, no cables are needed to connect from one point to another. These connections can be used for speech, e-mail, surfing on the Web and transmission of audio and video. The most widespread use is mobile telephones. Wireless networks are also used for communication between computers. This note focuses on ways to set up wireless connections between computers. It gives a basic overview without becoming too technical. It will help to determine whether a wireless network might be a suitable solution. It also is a guide to more resources. Many links are to a document by Mike Jensen. The links used are examples; they are not preferred products.
AN ALL-IP 4G NETWORK ARCHITECTURE
The overall 4G architecture discussed in this paper is IPv6-based, supporting seamless mobility between different access technologies. Mobility is a substantial problem in such environment, because inter-technology handovers have to be supported. In our case, we targeted Ethernet (802.3) for wired access; Wi-Fi (802.11b) for wireless LAN access; and W-CDMA - the radio interface of UMTS - for cellular access (Fig. 1). With this diversity, mobility cannot be simply handled by the lower layers, but needs to be implemented at the network layer. An "IPv6-based" mechanism has to be used for interworking, and no technology-internal mechanisms for handover, neither on the wireless LAN nor on other technology, can be used. So, in fact no mobility mechanisms are supported in the W-CDMA cells, but instead the same IP protocol supports the movement between cells.
PROVIDING QUALITY OF SERVICE
The design principle for QoS architecture was to have a structure which allows for a potentially scalable system that can maintain contracted levels of QoS. Eventually, especially if able to provide an equivalent to the Universal Telephone Service, it could possibly replace today's telecommunications networks. Therefore, no specific network services should be presumed nor precluded, though the architecture should be optimised for a representative set of network services. Also, no special charging models should be imposed by the AAAC system, and the overall architecture must be able to support very restrictive network resource usage. In terms of services, applications that use VoIP, video streaming, web, e-mail access and file transfer have completely different prerequisites, and the network should be able to differentiate their service. The scalability concerns favour a differentiated services (DiffServ) approach [5]. This approach is laid on theassumption to control the requests at the borders of the network, and that end-to-end QoS assurance is achieved by a concatenation of multiple managed entities.
Handover with QoS guarantees
One of the difficult problems of IP mobility is assuring a constant level of QoS. User mobility is assured in our network by means of fast handover techniques in conjunction with context transfer between network elements (ARs - old and new – and QoS Brokers).
When the quality of the radio signal in the MT to the current AR (called “old AR”, AR1) drops, the terminal will start a handover procedure to a neighbouring AR (called “new AR”, AR2) with better signal and from which it has received a beacon signal with the network prefix advertisement. This handover has to be completed without user perception, when making a voice call, e.g.. For achieving this, the MT will build its new care-of-address and will start the handover negotiation through the current AR, while still maintaining its current traffic. This AR will forward the handover request to both the new AR and to the QoS Broker.
CONCLUSION:
We presented an architecture for supporting end-to-end QoS. This QoS architecture is able to support multi-service, multi-operator environments, handling complex multimedia services, with per user and per service differentiation, and integrating mobility and AAAC aspects. The main elements in our architecture are the MT, the AR and the QoS Brokers. We discussed the simple interoperation between these elements and depicted the overall QoS concept. With our approach, very little restrictions are imposed on the service offering. This architecture is currently being evolved for large testing in field trials across Madrid and Stuttgart. Being an architecture specially targeted to support real time communications over packet networks, the network elements configuration must be well dissected. The simulation study summarized in the paper was a valuable input to the QoS Broker implementation and policies design, providing simple heuristics to properly configure the access routers to achieve the best possible performance.
[attachment=60471]
Abstract
This paper describes an architecture for differentiation of Quality of Service in heterogeneous wireless-wired networks. This architecture applies an “all-IP” paradigm, with embedded mobility of users. The architecture allows for multiple types of access networks, and enables user roaming between different operator domains. The overall 4G architecture discussed in this paper is IPv6-based, supporting seamless mobility between different access technologies. Mobility is a substantial problem in such environment, because inter-technology handovers have to be supported. In our case, we targeted Ethernet (802.3) for wired access; Wi-Fi (802.11b) for wireless LAN access; and W-CDMA - the radio interface of UMTS - for cellular access.The architecture is able to provide quality of service per-user and per-service An integrated service and resource management approach is presented based on the cooperative association between Quality of Service Brokers and Authentication, Authorisation, Accounting and Charging systems. The different phases of QoS-operation are discussed. The overall QoS concepts are presented with some relevant enhancements that address specifically voice services. In particular, EF simulations results are discussed in this context.
INTRODUCTION
WIRELESS COMMUNICATION:
A wireless network is an infrastructure for communication “through the air”, in other words, no cables are needed to connect from one point to another. These connections can be used for speech, e-mail, surfing on the Web and transmission of audio and video. The most widespread use is mobile telephones. Wireless networks are also used for communication between computers. This note focuses on ways to set up wireless connections between computers. It gives a basic overview without becoming too technical. It will help to determine whether a wireless network might be a suitable solution. It also is a guide to more resources. Many links are to a document by Mike Jensen. The links used are examples; they are not preferred products.
AN ALL-IP 4G NETWORK ARCHITECTURE
The overall 4G architecture discussed in this paper is IPv6-based, supporting seamless mobility between different access technologies. Mobility is a substantial problem in such environment, because inter-technology handovers have to be supported. In our case, we targeted Ethernet (802.3) for wired access; Wi-Fi (802.11b) for wireless LAN access; and W-CDMA - the radio interface of UMTS - for cellular access (Fig. 1). With this diversity, mobility cannot be simply handled by the lower layers, but needs to be implemented at the network layer. An "IPv6-based" mechanism has to be used for interworking, and no technology-internal mechanisms for handover, neither on the wireless LAN nor on other technology, can be used. So, in fact no mobility mechanisms are supported in the W-CDMA cells, but instead the same IP protocol supports the movement between cells.
PROVIDING QUALITY OF SERVICE
The design principle for QoS architecture was to have a structure which allows for a potentially scalable system that can maintain contracted levels of QoS. Eventually, especially if able to provide an equivalent to the Universal Telephone Service, it could possibly replace today's telecommunications networks. Therefore, no specific network services should be presumed nor precluded, though the architecture should be optimised for a representative set of network services. Also, no special charging models should be imposed by the AAAC system, and the overall architecture must be able to support very restrictive network resource usage. In terms of services, applications that use VoIP, video streaming, web, e-mail access and file transfer have completely different prerequisites, and the network should be able to differentiate their service. The scalability concerns favour a differentiated services (DiffServ) approach [5]. This approach is laid on theassumption to control the requests at the borders of the network, and that end-to-end QoS assurance is achieved by a concatenation of multiple managed entities.
Handover with QoS guarantees
One of the difficult problems of IP mobility is assuring a constant level of QoS. User mobility is assured in our network by means of fast handover techniques in conjunction with context transfer between network elements (ARs - old and new – and QoS Brokers).
When the quality of the radio signal in the MT to the current AR (called “old AR”, AR1) drops, the terminal will start a handover procedure to a neighbouring AR (called “new AR”, AR2) with better signal and from which it has received a beacon signal with the network prefix advertisement. This handover has to be completed without user perception, when making a voice call, e.g.. For achieving this, the MT will build its new care-of-address and will start the handover negotiation through the current AR, while still maintaining its current traffic. This AR will forward the handover request to both the new AR and to the QoS Broker.
CONCLUSION:
We presented an architecture for supporting end-to-end QoS. This QoS architecture is able to support multi-service, multi-operator environments, handling complex multimedia services, with per user and per service differentiation, and integrating mobility and AAAC aspects. The main elements in our architecture are the MT, the AR and the QoS Brokers. We discussed the simple interoperation between these elements and depicted the overall QoS concept. With our approach, very little restrictions are imposed on the service offering. This architecture is currently being evolved for large testing in field trials across Madrid and Stuttgart. Being an architecture specially targeted to support real time communications over packet networks, the network elements configuration must be well dissected. The simulation study summarized in the paper was a valuable input to the QoS Broker implementation and policies design, providing simple heuristics to properly configure the access routers to achieve the best possible performance.