Exploiting regional differences: A spatially adaptive random access

In this paper, we discuss the potential for improvement of the simple random access scheme by utilizing local information such as the received signal-to-interference-plus-noise-ratio (SINR). We propose a spatially adaptive random access (SARA) scheme in which the transmitters in the network utilize different transmit probabilities depending on the local situation. In our proposed scheme, the transmit probability is adaptively updated by the ratio of the received SINR and the target SINR. We investigate the performance of the SARA scheme. For comparison, we derive an optimal transmit probability of ALOHA scheme in which all transmitters use the same transmit probability. We illustrate the performance of the SARA scheme through simulations. We show that the performance of the proposed scheme surpasses that of the optimal ALOHA scheme and is comparable with the CSMA/CA scheme.