Optimal CSMA Scheduling with Look Ahead Mechanism for Multihop Wireless Networks

Optimal CSMA scheduling algorithms such as QCSMA suffer from large delay, mainly due to the strong correlations residing in consecutive link schedules. Some previous works have remedied this issue with multiple instances of the scheduler, but the baseline scheduler (Q-CSMA) itself remains untouched. By noticing the inherent inefficiency in the contention mechanism of Q-CSMA, we propose LA-CSMA algorithm in which each link looks ahead (LA) its state update in advance and utilizes this free information during the contention stage. We show that our algorithm achieves optimal throughput with reduced correlation in the service process, thereby leading to significantly smaller delay without any additional overhead.