Improving the queue size and delay performance with the I-CSMA link scheduling algorithm

In a prior work, we proposed a new CSMA-like randomized link scheduling algorithm for wireless networks, called I-CSMA, based on a modified version of the Ising model in physics. I-CSMA is a generalization of earlier Glauber-dynamics-based algorithms, and it was shown to be throughput-optimal. In this paper, we evaluate the queue size/delay performance of I-CSMA. The simulation results show that, while maintaining throughput-optimality, I-CSMA gives better queue-size/delay performance than the popular Q-CSMA algorithm. The improvement is significant and consistent, particularly in the regime of low to moderately high traffic intensity. We analyze the control overhead of I-CSMA, discuss parameter tuning for the algorithm, and show the effects of parameter tuning with simulation results. We also propose a simpler, heuristic I-CSMA algorithm and show that it has similar performance as I-CSMA. To make I-CSMA immediately useful, we provide a device-based implementation of the I-CSMA algorithm as a reference implementation.