An efficient QoS guaranteed MAC protocol in wireless ATM networks

Abstract

In order to provide QoS guarantees in the wireless networks, wireless ATM (WATM) is suitable to be the framework. With an appropriate medium access control (MAC) protocol, WATM can support multimedia service efficiently and guarantee their QoS requirements. Due to limitation of wireless bandwidth available, an efficient wireless ATM MAC protocol is needed. A new MAC protocol, named CRPMA/DS (combination of reservation and polling multiple access with distributed scheduling), is proposed to support various ATM services, such as CBR, VBR, ABR and UBR. CRPMA/DS is based on a distributed scheduling architecture to access the shared wireless bandwidth. Each mobile terminal (MT) can handle its connections more efficiently according to its requirements. CRPMA/DS also uses a scheme with the proposed contention resolution algorithm to solve the request collision and VBR bursty problems. We simulate our proposed MAC protocol and compare its performance with DTDMA/PR and PRMA/DA. The simulation results show that CRPMA/DS has higher throughput of data traffic (ABR and UBR traffic) and still guarantees the QoS of CBR and VBR traffic. With the contention resolution algorithm, CRPMA/DS also provides a low collision probability when the MTs send their requests in the reservation period.