Design and performance evaluation of broadband wireless MAC protocols

The success of the ATM (Asynchronous Transfer Mode) multiplexing and switching technique and the increased popularity of the wireless networks have motivated the vision of the WATM (Wireless ATM). This thesis contributes to the ongoing research on the WATM, focusing on the design and performance evaluation of the broadband Medium Access Control (MAC) protocol. The objective of this thesis is to design an efficient broadband MAC protocol, and provide comprehensive insights on the dynamic behavior of different MAC subsystem issues, traffic behavior, and the performance merits of several traffic and network management mechanisms. The proposed MAC protocol is designed to reduce the channel access delay problem, the connection termination probability, and to guarantee the QoS (Quality of Service) levels.; Central to our work is the use of D-TDMA (on Demand-Time Division Multiple Access) as the core scheme for the Uplink transmission, while S-Aloha (Slotted-Aloha) is used as the channel access scheme. A key issue is the channel access delay, which would affect the inprogress variable bit rate services. This thesis has addressed this issue and proposed different schemes for improving the performance. Another key issue is the QoS (Quality of Service) guarantee during the bandwidth assignment on demand. A proposed polling mechanism at the connection reestablishment phase provided significant performance improvement, as well as the ability to determine the status of the inprogress variable bit rate services that are in the OFF period.; The performance of the proposed DD-PAMA (Dynamic Demand-packet Assignment Multiple Access) protocol, along with the proposed management mechanisms, is shown to produce better performance compared with other reported broadband MAC protocols. DD-PAMA protocol along with the PR-BRA (Polling Respond-Bandwidth Reassignment Algorithm) are the key contributions in this thesis.; It is imperative to understand the dynamic behavior of the multiplexed streams of different traffic classes. This issue is investigated, and it was found that the ABR (available bit rate) services dominate the wireless channel bandwidth and deny a fair bandwidth share to the VBR applications under no control mechanisms. Several management mechanisms are investigated in order to stabilize the network performance and constrain the ABR services dominant behavior.