Coverage Extension of WiMax using Multihop in a Low User Density Environment

The usage of multihop transmission enables a cost efficient extension of the coverage of a base station (BS) especially in low user density environment. In this paper, a network consisting of BSs and fixed subscriber stations (SSs) is considered in which the SSs are capable to act as relay stations (RSs). SSs con-nected to a BS forward the traffic to SSs at the cell border not having a direct link to a BS. The IEEE 802.16 (WiMax) standard defines a mesh mode enabling multihop transmission and communication between SSs. In this paper, the connectivity of a cellular multihop network based on IEEE 802.16 is analyzed. The maximum number of hops of a connection is limited to two. Even with a low density of SSs, the cell size can be in-creased. Increasing cell radius leads to a higher fraction of multihop connections and a higher usage of robust modulation and coding schemes (MCS) which causes a decreasing cell throughput