Dimensioning cellular networks with fixed relay stations

We analyze the downlink spectral efficiency of multicellular wireless networks where in each cell in addition to the base station (BS) a certain number of relay stations (RS) are deployed. It is observed that by introducing more relay stations, the spectral efficiency in b/s/Hz per cell area increases. Hence, for a fixed spectral efficiency, the cell radius can be increased. These two aspects are important since by deployment of relay stations, the existing cellular systems could get better efficiency and the new cellular system could be designed with a smaller density of BS on the same geographical area. Deployment costs can therefore be significantly reduced depending on the relative costs between RS and BS.