Reservation arbitrated access for variable bit rate isochronous traffic transport over dual bus metropolitan area networks

by Chan, Henry C.

IEEE 802.6 is an international standard for metropolitan area networks (MANs) based on a dual bus architecture. In addition to its deployment for interconnecting local area networks (LANs), 802.6 MANs can also be used as broadband multiplexers for integrating different types of traffic over broadband integrated services digital networks employing asynchronous transfer mode (AlhiI/BISDN) and as distributive switches to support wireless personal communication services. This thesis proposes a novel reservation arbitrated (RA) access protocol for transporthg variable bit rate isochronous traffic (VBRIT) such as packet voice and video over duaI bus MANS in general and IEEE 802.6 MANs in particular. RA access allows a variable bit rate isochronous source (VBRS) to capture and reserve isochronous channels on a bandwidth on demand basis yielding substantial capacity improvements over pre-arbitrated (PA) access and providing a guaranteed transport service compared to queue-arbitrated (QA) access. To resolve possible access contention in the reservation process, a simple resolution mechanism is proposed where the upstrearn nodes yield to the downstream nodes during the confirmation stage. Nevertheless the contention problem can be completely eliminated under the typical coverage area of a MAN by setting the operation parameters properly. A rich farnily of RA access protocols cm be found based on different methods of acquiring the incremental bandwidth. In particular, a new cyclic capturing mechanism is proposed to provide fair access service. The performance of RA access is analyzed extensively by analytical methods and computer simulations based on different VBRS models covering voice, video conference and motion video traffic. Three methods: uncontrolled bandwidth sharing, dynarnic bandwidth partitioning and dynarnic bandwidth sharing and the associated connection admission control (CAC) mechanisms are evaluated for multiplexing heterogeneous VBRIT. A movable boundary integration scheme is proposed to integrate PA, QA and RA traffic efficientiy which gives significant capacity improvement over existing integration methods in the 802.6 standard. An important application of RA access is to facilitate the efficient transport of real time traffic over MAN-based personal communication networks and enterprise networks. Abstract List of Figures List of Tables