Joint Random Access Control Scheme based on PRACH Channel Quality and Access Class Barring

摘要

In massive communication networks, bursty traffic may cause an unexpected network overload. Traditionally, the access class barring (ACB) based random access (RA) schemes perform well in controlling network overload. However, as the number of contention devices increases, the performance of the ACB-based access control mechanism degrades severely, especially in terms of access success probability and average access delay. In recognition of the fact that existing ACB-based RA scheme does not take the influence of the physical random access channel (PRACH) state on RA performance into consideration, in this paper, we propose a joint RA control scheme involving two access check mechanisms, i.e., ACB check and PRACH channel quality check. As a result, the proposed joint scheme can not only reduce the number of contention de-vices in each RA slot through ACB check but also guarantee the success of preamble (PA) detection by means of PRACH quality check. Simulation results show that the proposed scheme outperforms the other ACB-based RA scheme in terms of access success probability, network load capacity, and the average number of PA transmission at the expense of increased total service time. As a result, compared with other access control mechanisms, the proposed scheme is more suitable for delay-tolerate services.