Proposal and Testbed System of Inter Radio System Switching 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 a testbed system. On this system, we have proved that data can be delivered continuously and radio systems can be switched correctly without any packet loss. Also, we present the evaluation result of the end-to-end latency on the testbed system.