A Markov Decision Process (MDP)-Based Congestion-Aware Medium Access Strategy for IEEE 802.15.4

IEEE 802.15.4 is a popular technology for short-range wireless networking due to the features such as low duty cycle operation, low power consumption, and both contention-based and contention-free transmissions. This standard can be enhanced to provide an optimal medium access mechanism in presence of congestion in the network. We present a Markov decision process (MDP)-based medium access control (MAC) model for IEEE 802.15.4 for the optimal use of contention and contention-free period to minimize energy consumption in repeated transmissions and carrier sensing without degrading latency in packet transmission. The simulation results show that the MDP strategy works more efficiently in presence of congestion when compared to a non- optimal (i.e., traditional) slotted CSMA/CA scheme.