Wireless networks for data and voice communications systems are establishing themselves as important components of traditionally fully hardwired networks. Initially popularized by the mobility they offered to data and voice users, wireless networks are increasingly being deployed as competition against wire-line and optical leased line provisions to businesses, infrastructure (cellular backhaul) applications, and as local loop for new entrants to the telecommunications market. These networks alleviate costs involved in hardwiring communication lines to user premises and allow fast deployment.
Wireless systems have also facilitated provision of new data/voice services to multitenant units (MTUs) and to businesses in built-up city centers in shorter deployment times, thus increasing the competitiveness of businesses using wireless facilities. Figure 1.1 illustrates a point-to-multipoint (PMP) wireless network deployed in an urban environment.
While edges of voice and data network experience the fast deployment of the wireless component, asynchronous transfer mode (ATM) technology is increasingly becoming the central technology in the workgroup and enterprise network environments and as the transport technology of choice in nationwide wide-area networks (WANs). ATM provides scalable bandwidths and quality-of-service (QoS) guarantees at attractive price performance points, facilitating a wide class of applications that can be supported in a single network. The bandwidth hungry applications spawned by the World Wide Web (WWW), as well as the general use of the Internet, telephony,
Wireless systems have also facilitated provision of new data/voice services to multitenant units (MTUs) and to businesses in built-up city centers in shorter deployment times, thus increasing the competitiveness of businesses using wireless facilities. Figure 1.1 illustrates a point-to-multipoint (PMP) wireless network deployed in an urban environment.
While edges of voice and data network experience the fast deployment of the wireless component, asynchronous transfer mode (ATM) technology is increasingly becoming the central technology in the workgroup and enterprise network environments and as the transport technology of choice in nationwide wide-area networks (WANs). ATM provides scalable bandwidths and quality-of-service (QoS) guarantees at attractive price performance points, facilitating a wide class of applications that can be supported in a single network. The bandwidth hungry applications spawned by the World Wide Web (WWW), as well as the general use of the Internet, telephony,
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video-on-demand (VOD), and videoconferencing have given rise to the need for simultaneously supporting the services on the same network. ATM is serving as the main catalytic technology in promoting the convergence of multiprotocol multiple networks into a single network providing multiple services.
ATM is designed to meet the requirements of both network service providers and end users. With ATM, service providers and end users can establish priorities based on the real-time nature of the traffic. Delaysensitive voice and real-time video traffic are often given the highest priority,and nondelay sensitive traffic such as e-mail and local-area network (LAN)traffic are given a lower priority. These priority levels allow the service providers to charge according to the QoS.
Because of ATM’s popularity and its potential for providing orders of magnitude of additional bandwidth for user traffic, traditionally popular networks are being forced to use ATM in internetworking arrangements. Such arrangements and standards that allow Internet Protocol (IP) networks and Frame Relay networks to coexist with ATM provide the current deployers of these networks the flexibility to evolve networks toward the most costeffective solution. Many such interconnected network arrangements already exist, and product offerings facilitating such arrangements are available today. Systems Network Architecture (SNA) and X.25 networks have internetworking arrangements to expand their life span in the predominantly IP,
Frame Relay, and ATM networking infrastructure.
Another important trend is the move toward voice systems to use packet networks. As the rate of growth of packet data networks began to exceed that of the circuit-switched telephony networks, the need to deploy packet networks to carry voice has overtaken the need to build circuitswitched networks to carry data. Voice-to-data network interworking and the need to carry Voice over Frame Relay (VoFR), IP, and ATM networks is increasingly important to the convergence of data and voice networks into an all packet network.
Convergence to an all ATM network requires that proper consideration be given to maintaining the same or better QoS that users expect from ATM networks while the data is transported via non-ATM networks. The QoS aspect is further complicated when a wireless segment is introduced at the edge of the ATM network. Air-protocols may often alter the traffic pattern of the ATM cells that are carried over it. Impact on QoS arising from such situations must be addressed in the design of wireless systems in broadband interworking environments.
This book focuses on the following technical aspects of the use of ATM technology in wireless broadband networks:
As current data networks evolve into ATM networks, and as voice and packet data networks converge toward a single multiservice network, the development of interworking solutions becomes critical. Different access methods, and the required interworking need for using IP, Frame Relay, and, ultimately, ATM as the transport network, are identified and detailed.
Interworking functionality that is currently employed, and the necessary interworking arrangements between the access protocols and the transport protocols will be described with detailed reference to authoritative compliance standards developed by organizations that are key players in the networking field. This book will also deal with how the mapping of traffic parameters between the components in an interworking arrangement is implemented to maintain the QoS that the network user expects the service provider to deliver.
Transition of the wireless component from an expensive segment into an integral part of the voice/data network will also be explored, and the performance impact on end-to-end voice/data sessions will be assessed. The effect of traffic parameters on QoS aspects in different protocol segments of the network will be detailed, and practical solutions on setting traffic parameters to accommodate the wireless component will be discussed. ATM will be used as the main network protocol in these discussions.
ATM is designed to meet the requirements of both network service providers and end users. With ATM, service providers and end users can establish priorities based on the real-time nature of the traffic. Delaysensitive voice and real-time video traffic are often given the highest priority,and nondelay sensitive traffic such as e-mail and local-area network (LAN)traffic are given a lower priority. These priority levels allow the service providers to charge according to the QoS.
Because of ATM’s popularity and its potential for providing orders of magnitude of additional bandwidth for user traffic, traditionally popular networks are being forced to use ATM in internetworking arrangements. Such arrangements and standards that allow Internet Protocol (IP) networks and Frame Relay networks to coexist with ATM provide the current deployers of these networks the flexibility to evolve networks toward the most costeffective solution. Many such interconnected network arrangements already exist, and product offerings facilitating such arrangements are available today. Systems Network Architecture (SNA) and X.25 networks have internetworking arrangements to expand their life span in the predominantly IP,
Frame Relay, and ATM networking infrastructure.
Another important trend is the move toward voice systems to use packet networks. As the rate of growth of packet data networks began to exceed that of the circuit-switched telephony networks, the need to deploy packet networks to carry voice has overtaken the need to build circuitswitched networks to carry data. Voice-to-data network interworking and the need to carry Voice over Frame Relay (VoFR), IP, and ATM networks is increasingly important to the convergence of data and voice networks into an all packet network.
Convergence to an all ATM network requires that proper consideration be given to maintaining the same or better QoS that users expect from ATM networks while the data is transported via non-ATM networks. The QoS aspect is further complicated when a wireless segment is introduced at the edge of the ATM network. Air-protocols may often alter the traffic pattern of the ATM cells that are carried over it. Impact on QoS arising from such situations must be addressed in the design of wireless systems in broadband interworking environments.
This book focuses on the following technical aspects of the use of ATM technology in wireless broadband networks:
As current data networks evolve into ATM networks, and as voice and packet data networks converge toward a single multiservice network, the development of interworking solutions becomes critical. Different access methods, and the required interworking need for using IP, Frame Relay, and, ultimately, ATM as the transport network, are identified and detailed.
Interworking functionality that is currently employed, and the necessary interworking arrangements between the access protocols and the transport protocols will be described with detailed reference to authoritative compliance standards developed by organizations that are key players in the networking field. This book will also deal with how the mapping of traffic parameters between the components in an interworking arrangement is implemented to maintain the QoS that the network user expects the service provider to deliver.
Transition of the wireless component from an expensive segment into an integral part of the voice/data network will also be explored, and the performance impact on end-to-end voice/data sessions will be assessed. The effect of traffic parameters on QoS aspects in different protocol segments of the network will be detailed, and practical solutions on setting traffic parameters to accommodate the wireless component will be discussed. ATM will be used as the main network protocol in these discussions.
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