A Tunable Cross-Layer Congestion Reducing Medium Access Control (CRMAC) Protocol for Wireless Networks

In recent years, development of a large variety of mobile computing devices have led to wide scale deployment and use of wireless ad hoc and sensor networks. Ad hoc Wireless LANs (WLANs) and sensor networks are prone to network congestion due to the bursty nature of data traffic. This results in an increase in the number of packets dropped due to buffer overflow, decrease in the overall network throughput and increase in packet delivery latency. In this paper, we propose a contention based, tunable cross-layer congestion reducing medium access control (CRMAC) protocol that uses buffer-status information from the network layer to reduce congestion and buffer overflows by giving prioritized medium access to congested nodes in the MAC layer. The performance of CRMAC has been compared with that of 802.11 and a generalized contention based fair medium access control protocol. Simulation results show that CRMAC can be easily tuned to meet the application-specific performance requirements and performs much better than the other two algorithms in terms of reducing the packet drops, increasing the network throughput and reducing the packet delivery delay or latency as needed by the application.