Fast cell select for mobility robustness in intra-frequency 5G ultra dense networks

Abstract

5th Generation (5G) mobile networks are required to support transmission of capacity demanding services such as real-time remote computing without any interruption. One of the candidate solution for high capacity is Ultra Dense Networks (UDNs). However, UDNs are characterized by fast change of the received signal by a user. The fast change of the signal and high speed of users create too many handovers and connection failures such as handover failures and Radio Link Failures (RLFs). Consequently, conventional handovers and connection failures are the major sources of service interruption. To achieve ultra-reliable communication by tackling the service interruptions, this paper proposes a novel multi-connectivity scheme that uses fast selection of serving cell from a set of prepared cells. A similar feature in Long Term Evolution — Advanced (LTE-A) that is defined under Coordinated Multi-Point (CoMP) transmission is Dynamic Point Selection (DPS). However, in DPS a cell is selected dynamically for transmission of only data signals. Transmission of mobility related control signals is performed through one primary cell which is changed through a conventional handover. Unlike DPS, this paper proposes that the selected cell, from the set of prepared cells, is used for transmission of both data and control signals. Simulation results show that the connection failures due to RLFs are considerably resolved by the proposed scheme.