This research presents the performance verification of a prototype WiMAX relay station that has been developed in the framework of the FP7 ICT REWIND (RElay-based WIreless Network and StandarD) project. The prototype operates at 3.5 GHz frequency band and supports a set of both networking and operational features been specified in the evolving IEEE802.16j standard. Performance field tests that are presented verify that the introduction of the prototype within the network provides extension of the base station coverage area, whereas, in parallel, it provides significant improvement in terms of throughput and signal-to-noise ratio.