User-dependent perfect-scheduling multiple access protocol for multihop wireless ad hoc networks

The ad hoc network is a wireless system without a fixed (wired or wireless) infrastructure. A key component of its design is the medium access control (MAC) protocol, with which multiple users share a common radio channel. A variety of transmission specifications have been proposed to provide wireless access. Most previously proposed specifications, however, cannot overcome the resource wastage problem satisfactorily. In this paper, we describe a novel multiple access protocol - user-dependent perfect-scheduling multiple access (UPMA) protocol that supports node mobility and multihop architecture. The protocol is designed based on the idea of contention reservation access and polling transmission. In the protocol, only the nodes that have packets to send contention to use channel and the nodes without traffic transmissions are immediately deleted from polling list, thus it improves channel utilization greatly. Moreover, a collision avoidance and resolution protocol is proposed to guarantee a node to access channel rapidly. Finally, the network performance for Internet data traffic is simulated and related results are given, which demonstrate that the UPMA protocol has a high throughput, low average packet transmission delay and small packet dropping probability.