CDMA Code-Based Bandwidth Request Mechanism in IEEE 802.16j Mobile Multi-Hop Relay (MMR)Systems

In the IEEE 802.16 system, a relay station (RS) is required for the purpose of coverage extension and throughput improvement. However, if we use the RS, original bandwidth request mechanism is not applied to subscriber station (SS) which is connected to RS since the bandwidth request mechanism is optimized for single-hop environment. Therefore, we propose an efficient contention based CDMA bandwidth request mechanism for SS located in RS region in the IEEE 802.16 MMR system. In the proposed scheme, an SS can receive the uplink resource very well wherever an SS is located. Through the analysis, we show that the proposed bandwidth request mechanism reduces the signaling cost and delay of system.