Power and retransmission control of multichannel slotted ALOHA networks using capture effect

Abstract

The packet collision in slotted ALOHA networks deteriorates the performance of the networks. Moreover, it causes the slotted ALOHA networks to be bistable. In this dissertation, we introduce the three control schemes to improve the throughput of multichannel slotted ALOHA networks using the capture effect and the adaptive control of retransmission probability. The first control scheme(s-ALOHA/RC) is to modify the retransmission probability using the feedback signal sent by the central station at each time slot. The second control scheme(s-ALOHA/P) is to induce the capture effect by the power difference among the transmission packets. The third control scheme (s-ALOHA/PRC) is the mixture of the first and the second one. It improves the performance of multichannel slotted ALOHA network using the capture effect and the adaptive control of retransmission probability. It is verified that the network throughput and the stability are improved by the above schemes.