Exploiting Processing Gain in Wireless Ad Hoc Networks Using Synchronous Collision Resolution Medium Access Control SchemesExploiting Processing Gain in Wireless Ad Hoc Networks Using Synchronous Collision Resolution Medium Access Control Schemes

Signal spreading is used in military wireless networks to make them more difficult to detect, jam, and intercept. With signal spreading comes the opportunity to use code division multiple access (CDMA) to create multiple channels using the same spectrum. The requirement for all nodes in ad hoc networks to receive broadcast transmissions from any of their neighbors has made implementing channelization schemes impractical, especially with contention protocols. When CDMA is the method of channelization, then the near far effect must also be addressed. In this paper, we describe these challenges and then how the contention based medium access control protocol, Synchronous Collision Resolution (SCR) solves them. We describe how SCR creates a geometry of transmitters that benefits from using CDMA. We provide results of several different types of simulation experiments that demonstrate the relative benefits of different levels of processing gain. We demonstrate that tuning SCR for the available processing gain dramatically improves throughput.