A load awareness medium access control protocol for single-hop wireless ad hoc networks

A contention-based wireless ad hoc medium access control (MAC) protocol, such as carrier sense multiple access with collision avoidance (CSMA/CA), has excellent efficiency when the system is light loaded. The main drawback of such protocols is their inefficiency and unbounded delay when the system load is heavy. On the other hand, a contention-free MAC protocol, such as token passing, has a better and fair throughput when the system is heavy loaded. The main drawback of such protocols is their inefficiency when only a small amount of users want to transmit. In this paper, we propose a new load awareness single-hop wireless ad hoc MAC protocol (which is called the LA protocol) that exploits the benefits of both contention-based and contention-free protocols. A contention-based MAC protocol is used when the system is light loaded and a contention-free one is used otherwise. Our LA protocol, which operates in a distributed fashion and is fully compatible with the IEEE 802.11 wireless local area network (WLAN) standard, can switch smoothly between the contention-based protocol and the contention-free one. Simulation results show that our protocol indeed extracts the better part of two kinds of protocols. Copyright (c) 2006 John Wiley & Sons, Ltd.