A Channel Aware MAC Protocol in an ALOHA Network with Selfish Users

We consider a game theoretic model incorporating channel state information into slotted ALOHA in a fading environment. Each user sets a threshold for her channel gain and sends a packet only when the channel gain is higher than the threshold at a given slot. This threshold is decided to maximize the net benefit of a user, utility minus power consumption. The asymptotic behaviors of the total throughput at a symmetric Nash equilibrium point are studied for fading and non-fading environments in a homogeneous system. It is shown that the total throughput in a fading environment increases as the number of users increases, while the total throughput in the simple classical slotted ALOHA decreases when users are sensitive enough to power consumption. Convergence to the symmetric Nash equilibrium is also studied.