EPC signaling load impact over S1 and X2 handover on LTE-Advanced system

Abstract

A small cell is one of key factors in a Long Term Evolution (LTE) and LTE-Advanced (LTE-A) system. its handover signaling load impact on the evolved packet core (EPC) network is a big issue when considering a benefit and efficiency of S1 and X2 handover (HO) in diverse handover scenarios due to tons of small cells. Therefore, the performance of the inbound handover signaling load on the control plane in EPC network with deployed home eNB (HeNB) has been analyzed and compared in this paper. According to the analysis results for the number of signaling messages, when comparing S1 and X2 inbound hand over, it is shown that the 70% and 108% of signaling messages are needed more over S1 handover in an overall procedure of the intra-MME/intra-SGW and intra-MME/inter-SGW handover respectively. With respect to handover signaling messages affecting EPC only, we also found that the 183% and 213% of signaling messages are needed more over S1 handover in the same case respectively. Furthermore, looking at the impacts of EPC signaling load, we obtained a signaling load of about 87% for the S1 handover and about 13% for the X2 handover in the simulation. Hence, we can conclude that a inbound hand over procedure affects EPC more severely than the other network nodes. EPC signaling load can be reduced by X2 handover more than six times when comparing to S1 handover scenarios.