Adaptive in-band full-duplex collision detection for balancing sensing and collision costs

Abstract

An undesirable side-effect of network densification is a reduced quality of service due to increased contention. One interesting solution to address this issue is full-duplex medium access control (MAC) with collision detection. By detecting collisions early on, a considerable amount of energy can be saved in dense networks. However, when traffic demand and, as a result, the collision rate decrease, the reduced collision time does not compensate for the increased power consumption of the full-duplex physical layer. This paper therefore investigates the trade-offs between two MAC protocols (i.e. full-duplex CSMA/CD and half-duplex CSMA/CA) proposing closed-form formulas to calculate the equilibrium point in terms of power consumption. Knowing this equilibrium, we propose a distributed algorithm that independently switches the MAC protocol of each node reducing the energy consumption of each node up to 33%.