Delay Sensitive Protocol for High Availability LTE Handovers

Abstract

Long delays during the handover process lead to dropped calls which deteriorate the network quality of service. In addition, these delays impede the incorporation of authentication during the handover process which exposes the handover process to attacks such as desynchronization, network masquerading and session hijacking. In this paper, a delay sensitive protocol is developed based on the neuro-fuzzy optimization process and tracking area partitioning into no handover region, low probability handover region and high probability handover region that facilitated advance buffering of the figures of merit. The protocol computes the average delays during the handover process such that handovers taking longer durations than the average value are queued in the mobility management entity (MME) buffer and dispatched in a first in first out (FIFO) basis. The conventional permitted duration between handover command and handover execution is between 0.5 seconds and 1.5 seconds. To prevent holding the network resources for long durations, a handover termination duration was set to the lower bound of this conventional permitted duration, which was 0.5 seconds, such that handovers taking longer this duration were explicitly dropped. The reduced delays during the handover process facilitated the incorporation of entities authentication before subscribers can be transferred to the target cell. Simulation results showed the developed protocol greatly reduced handover delays to an average of 0.048 seconds. In addition, the source evolved Node-B (eNB), user equipment (UE) and target eNB were able to authenticate each other to boost security during the handover process.