In order to enable rapid and cost-effective deployment of WiMAX networks, relay technology which does not require backhaul line, can be considered as an essential feature for performing a successful business development. In the scope of a proposed Multi-Hop relay network architecture, (based on the recently developed IEEE 802.16j standard in order to enhance throughput, network coverage and capacity density), we provide an essential description of the Relay Station Software architecture design (PHY and MAC layers architecture), as it has been proposed by the REWIND European Research Program. The corresponding relay node is based on a highly integrated SoC device, which incorporates all baseband processing (PHY, MAC and CS), networking and control processors required for the relay station functionality. Thus, the Relay node software shall run all the PHY, MAC, scheduler and networking functionalities, required to operate a complete BS with relay functionality, and to integrate the node into the relay network.