A Survey on Spectral Handoff Mechanisms for the Cognitive Radio Network

Abstract

Abstract-In a cognitive radio network, the cognitive radio (CR) devices also called as secondary users (SU's) need to change their operating frequency due to the inclusion of primary user (PU) in that frequency band. Thus when a PU arrives in a frequency band and asks for a channel in that band, it gets that band and occupies the channel which may be occupied by a SU. In this situation, the SU needs to find another channel in a different frequency band which leads to the spectral handoff. Thus in addition to the location based handoff's for the SU, spectral handoff also occur. This spectral handoff may be done several times for the SU. Thus this situation leads to the study of handoff mechanism. This paper carries out a survey of the handoff types and their mechanisms which have been already conceptualized.