A Hybrid Spectrum Mobility and Handover Protocol in 3GPP Cognitive LTE Systems

Abstract

Many researches show that the current approach of fixed spectrum allocation caused the most of idle resources being unused by other wireless devices. Cognitive Radio (CR) is the novel system that improves the low utilization spectrum, with software-defined radio (SDR) devices of reconfigurable and switching spectrum resources to enhance the appropriate spectrum access and sharing. The new network technology long term evolution (LTE) systems have been proposed and this technique has highly flexible bandwidth and spectrum agile to satisfy the CR network. For the purpose of spectrum selection and mobility, we propose a hybrid spectrum mobility and handover protocol that based on the Poisson distribution of spectrum resources and consider the different spectrum holes characters to compute the expected transmission time of each spectrum hole. The minimum expected transmission time makes an appropriate spectrum holes selection to spectrum mobility and the makes the secondary user to select the adaptive base station to handover. Simulation results have shown that the proposed protocol is able to select spectrum holes adaptively and reduce the spectrum mobility ratio.