Cell Dimensioning and Network Throughput in Cellular Multi-Hop Relay Networks

In this paper we look at the network throughput and efficiency of a cellular system employing multi-hop relaying. It is shown that multi-hop relaying can provide great improvement in the area averaged spectral efficiency (measured in bits/second/Hz per unit area of coverage) of a system. However, the number of relays introduced and the dimensions of coverage areas of relays must be carefully chosen for the specific propagation environment and system parameters, otherwise poorer efficiency may result. Some example designs for the 5 GHz unlicensed band are given to illustrate some design considerations. Realistic simulated throughput, considering physical and medium access control layer overhead, of a HiperMAN or 802.16 system together with noise and interference calculations are used to determine potential real-world performance of such systems. Calculations for one to four relay hops are presented and designs´ area averaged spectral efficiencies are compared.