A Distributed Random Access Protocol with Enhanced Routing in Time-Slotted MANETs

In Mobile Ad hoc NETworks (MANETs), random access and dynamic routing are two critical techniques for mobile nodes to convey information without centralized scheduling. Conventionally, random access and dynamic routing are implemented at the Medium Access Control (MAC) and the network layer, respectively. However, the current MAC protocol Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) cannot support dynamic routing efficiently. To overcome this limitation, we shall propose a cross-layer protocol which takes dynamic routing into consideration when the mobile nodes contend to access the channel. In the proposed distributed protocol, the routing packets of the network layer are transmitted within the contention period. Since the transmission of routing packets is separated from data transmission in the time-domain, our cross- layer protocol eliminates the collision caused by the transmission of short routing packets. Simulation results will show that our design could significantly improve the system performance at both the MAC and network layers.