Performance Evaluation of Deadline Monotonic Policy Over 802.11 Protocol

Real time applications are characterized by their delay bounds. To satisfy the Quality of Service (QoS) requirements of such flows over wireless communications, the authors enhance the 802.11 protocol to support the Deadline Monotonic (DM) scheduling policy. Then, they propose to evaluate the performance of DM in terms of throughput, average medium access delay and medium access delay distribution. To evaluate the performance of the DM policy, they develop a Markov chain based analytical model and derive expressions of the throughput, average MAC layer service time and service time distribution. Therefore, they validate the mathematical model and extend analytical results to a multi-hop network by simulation using the ns-2 network simulator.