Using fuzzy logic to reduce ping-pong handover effects in LTE networks

Recently, mobile communications have been widely used in people’s everyday lives. Their handover process facilitates people to transfer an ongoing call or a data session from one service area to another without conducting any communication interruption. However, in mobile communications, the ping-pong effect is a serious problem since it may cause unnecessary handover and lead to data loss and high computation cost. This is the case when a user equipment (UE) moves between two or among more evolved Node Bases (eNBs), due to signal strength reason, the UE in a very short time period alternatively switches among the eNBs. Consequently, the eNBs bounce the communication link the UE connected to them back and forth. Although several previous researches have been made to mitigate the ping-pong effect, what seems to be lacking is effectively eliminating unnecessary handover. Therefore, in this paper, we propose a fast and simple fuzzy-logic-based handover decision system, named Fuzzy based Low Ping-Pong Effect Handover System (FPEHS for short), to reduce the ping-pong effect in an LTE network. In the FPEHS, five parameters, including current signal-to-noise ratio (SNR), detected SNR, bandwidth of serving eNB, bandwidth of target eNB, and remaining energy of the underlying user’s device, are inputted to the fuzzy logic unit to make handover decision. Our simulation results show that the FPEHS can effectively decrease the ping-pong effect about 92.94 % in average compared with that of the standard LTE’s handover mechanism.