Handover in Mobile Wireless Communication Network - A Review

Abstract

Mobility is the characteristics of mobile communication that makes it irresistible by all and sundry. The whole world is now engaging in wireless communication as it provides users' ability to communicate on-the-go. This is achieved by transferring users from a radio network to another. This process is called handover. Handover occurs either by cell crossing or by deterioration in signal quality of the current channel. The continuation of an active call is a critical characteristic in cellular systems. Brief overview of handover, handover type, commonly used handover parameters, some methods employed in the literature and we present the convergent point for furtherance in the area of mobile wireless communication Handover. Keywords-Wireless Communication Network, Handover, GSM and CDMA. I. INTRODUCTION The major characteristics that made wireless cellular communication system WCCS an indispensable is mobility. Handover is the process of achieving Continuous service as the user moves in-between cells. Handover is needed during cell-crossing or/and signal quality degradation in the current channel. During handover, there is switching among networks and thereby transfer users to another network or BS [45]. The fundamental of 5G is heterogeneous networks and in such networks, seamless handover in non-negotiable [46]. Phases of handover are: discovery, decision and execution. Network discovery finds appropriate network that satisfies user desired QoS. Decision phase is when the handover should take place (also known as a handover initiation phase). These phases determine seamlessness of the handover. Wrong time of initiation leads to unnecessary handover or call drop rate is increased and thereby result to poor QoS. Therefore, handover should take place at the right time by trigger handover decision considering all the parameters properly to ensure QoS is not affected and unnecessary handover is avoided.