In this paper, we have conducted a detailed survey on relay technologies for IEEE 802.16j mobile multi-hop relay networks, such as relay modes, relay transmission schemes, and relay pairing schemes. We have also conducted a detailed survey about the technical issues in the physical layer, medium access control-common part sub layer, and medium access control-security sub layer of IEEE 802.16j mobile multi hop relay networks. Technical issues such as data forwarding schemes, frame structure for transparent and non-transparent relay mode, link adaptation, modulation, and coding, belong to the physical layer. Other technical issues such as quality of service-scheduling services, bandwidth allocation and request, network planning, medium access control handover procedures, connection management, path management, and interference management belong to the medium access control- common part sub layer. Centralized security control and distributed security control belong to the medium access control--security sub layer. In this paper, we have also given how to integrated IEEE 802.16j (worldwide interoperability for microwave access) with IEEE 802.11(Wi-Fi).