Adaptive Spectrum Handoff Scheme in Cognitive Radio Ad-Hoc Networks
Atif Shakeel, Riaz Hussain, Adeel Iqbal, Irfan Latif Khan, Shahzad Ali Malik, Babatunji Omoniwa · 2018
Cognitive radio improves the spectrum utilization by permitting the secondary users in accessing the underutilized spectrum band of the primary network in an opportunistic manner. Spectrum handoff is considered as one of the important phases in cognitive cycle, where the secondary users have to vacate the occupied channel on the appearance of primary user for maintaining the QoS requirements of both primary and secondary communication. It also helps secondary users to find an appropriate target channel to resume its undone transmission either through switching handoff scheme or non-switching handoff process. The process of spectrum handoff becomes more critical in cognitive radio ad-hoc networks, as the coordination among the secondary users is a challenging task. This research presents an analytical model for the performance evaluation of secondary users, in terms of extended data delivery time for both switching and non-switching spectrum handoff in ad-hoc network environment. Channel rendezvous among secondary users is achieved usings of common control channel. The results achieved are based on preemptive resume priority M/M/1 queuing network, considering varying number of secondary users, their average arrival and service time. An adaptive spectrum handoff is proposed based on the primary user traffic intensity, number of SU and total number of primary channels.