Implementation and Performance Analysis of DCWA MAC Protocol for Multihop Wireless Networks
Performance of multi-hop ad hoc networks is severely affected by the hidden and exposed node problems. They are based on handshaking protocol used in the IEEE 802.11 standard was designed to solve the hidden node problem, however it was not successful in completely solving the problem. This paper presents a performance evaluation of adaptive back off algorithm based on Deterministic Contention Window Allocation (DCWA) on top of IEEE 802.11 Distributed Coordination Function (DCF) standard. The DCWA protocol relies on real-time measurements of the number slots being used in specified cycle time. This algorithm judiciously sets the upper and lower bounds for the contention window in order to adapt to the congestion level in the shared medium at that point in time. This paper provides an extension to DCWA in evaluating its performance over noisy channels with varied network density.