Dynamic frame scheduling with load balancing for IEEE 802.16j

In this paper, we consider a multi-hop relay networks in IEEE 802.16j system with the full frequency-reuse capability, in which a frame structure can be asymmetrically divided into two different intervals, one for access zone to base station (BS)/relay station (RS)-mobile stations (MSs) communication and the other for relay zone to BS-RS communication, while the same radio resource is fully reused by every RS in the cell. This paper proposes a frame scheduling algorithm that improves the overall system throughput by reducing waste of radio resource through balancing of resource allocation in each relay station (RS). The proposed algorithm is divided into two stages: first, a boundary between access zone and relay zone is scheduled by BS and determined dynamically; second, traffics that will be retransmitted by automatic repeat request (ARQ) and generated by difference between current and scheduled MCS (modulation and coding scheme) level are scheduled by RS. The simulation results show that proposed algorithm improves the overall system throughput approximately by 35% over a conventional frame scheduling algorithm without any load balancing capability.