PUSH: Proactive Unified Spectrum Handoff in CR-MANETs

In this paper, Proactive Unified Spectrum Handoff (PUSH) scheme in cognitive radio mobile ad hoc networks (CR-MANETs) through an established route is considered in which the channel availability depends on the Primary User´s (PU´s) activity, secondary user´s (SU´s) mobility, and the channel heterogeneity. First, an analytical model for Unified Spectrum Handoff (USH) scheme is introduced in which the SUs will move to another unused spectrum band, giving priority to a PU. Then, the PUSH method is proposed in which a handoff threshold is used to initiate the handoff proactively. When a channel handoff cannot be performed due to the SU´s mobility, a local flow handoff (LFH) is performed. The proposed PUSH algorithm uses the cognitive link availability prediction while considering the PU interference boundary to estimate the maximum link accessibility period. Based on the analytical model, the channel heterogeneity and the SU´s mobility affected the performance of the handoff management method rather than the PU´s activity. Both the simulation and analytical results demonstrated an improvement of route maintenance probability based on the LFH and cognitive link availability prediction mechanisms in PUSH.