Versatile medium access control (VMAC) protocol for mobile sensor networks

In this thesis, the problem of mobility handling in wireless sensor network is introduced with an appreciation for the applications that may be possible once the problem is resolved. Mobility handling is solved with a simple priority backoff technique inspired by novel MAC protocols. To incorporate this technique for stationary and mobile sensor nodes, a hybrid MAC protocol called VMAC is designed with a fixed frame length. VMAC combines the advantages of scheduled-based MAC for energy savings and contention-based MAC for short transmission delays. To exploit network bandwidth, channel reuse is encouraged and is readily integrated into the protoco\. To evaluate VMAC and its performance when compared to other MAC protocols, an implementation inside NS-2 is conducted with simulations of various topologies. These topologies vary in hop-count from source to destination and also contention levels. Simulation results show that VMAC with certain frame lengths are suited for selected topologies, but the frame length of one can always provide sufficient performance. The backoff technique is shown to be fair when nodes contend for medium access and it is even resourceful in speeding up hardware address resolution and routing.