The impact of energy constraints on the medium access

Contemporary mobile devices are battery powered and due to their shrinking size and increasing complexity operate on a tight energy budget. Thus, energy consumption is becoming one of the major concerns regarding the current and upcoming wireless communication systems. On the other hand, the available bandwidth resources are limited and modern applications are throughput demanding, leading thus to strong competition for the medium. In this direction, we consider a stochastic contention based medium access scheme, where the devices may choose to turn off for some time in order to save energy. We perform an analysis for a slotted ALOHA scenario and we show that the energy constraints, if properly exploited, may reduce contention for the medium. Our results give valuable insights on the energy--throughput tradeoff for any contention based system.