Simulation and Basic Experiment of Inter Radio System Handover for Cognitive Radio

Cognitive radio system consists of multiple wireless accesses that cover overlapping area, and cognitive terminals that use one or more of the wireless accesses simultaneously. In this paper, we propose the architecture of the cognitive radio system, and the inter-system handover protocols. In the proposed architecture, each cognitive terminal, that has multiple radio systems, operates with a single local IP address. The control sequence and packet format are designed to achieve fast handover among the radio systems. Based on the proposed architecture, we have developed both a simulator and a testbed system with WiMAX and wireless LAN. Through simulation and testbed, we have proved that stream data can be delivered continuously without any effects of the handover. Also, we present the evaluation result of the end-to-end latency on the testbed system.