Distributed Channel Access Scheduling for Ad Hoc Networks

Using two-hop neighborhood information, we develop four approaches for time-division channel access scheduling in ad hoc networks with omni-directional antennas, which are derived from a novel approach to contention resolution that allows a group of contenders to elect deterministically one or multiple winners in a given contention context (e.g., a time slot). Except for the node activation multiple access (NAMA) which schedules communications through a single channel, the link activation multiple access (LAMA), pair-wise link activation multiple access (PAMA) and hybrid activation multiple access (HAMA) are all dependent on the physical layer that is capable of creating multiple channels using the code division multiplexing scheme. The throughput and delay characteristics of these protocols in randomly generated multihop wireless networks are studied by analyses and simulation, and their performances are compared against a well-known static scheduling algorithm based on complete topology information, and the ideal CSMA and CSMA/CA protocols. Keywords—Channel access scheduling, medium access control protocol, MAC, ad hoc network.