Performance Analysis and UE-Side Improvement of Extended Access Barring for Machine Type Communications in LTE

In cellular based machine type communications (MTC), random access (RA) overload is a serious issue because in some use cases enormous MTC user equipments (UEs) try to access the network almost simultaneously. Extended access barring (EAB) is proposed in 3GPP to prevent the network from a complete collapse in such scenario. In EAB, the UEs are notified of overload control information through paging message and system block information (SIB). In this paper, we first analyze the impact factors of EAB. Based on the analysis, the delay caused by the notification mechanism results in RA failures in both the barring phase and the release phase. It is a self-limiting factor of EAB and cannot be completely eliminated by eNodeB side operation. In order to address this problem, we propose a UEside improvement scheme which efficiently improves the access performance of both individual UE and the entire network.