An infrastructure cost evaluation of single- and multi-access networks with heterogeneous traffic density

Traditional performance measures like capacity, cell radius and supported QoS are often insufficient when comparing wireless networks with different network architectures and cost structures. Instead, in this paper, infrastructure cost is used to compare different operator deployed single- and multi-access wireless networks, including 3G, WLAN and proposed 4G radio access technologies. For this purpose a model for the geographical distribution of traffic is introduced. Despite the spatially non-uniform traffic demand, single-access solutions like WCDMA high-speed downlink packet access (HSDPA) or long-term 3G evolved, with high capacity macro cellular base stations, typically yield the lowest costs per user. In particular this holds for a hypothetical long-term 3G evolved system operating in 450 MHz spectrum, which indicates the importance of good coverage. Operator deployed WLAN-only solutions are more expensive even for small fractions of supported users. Multi-access solutions, combining for example WCDMA DCH or HSDPA with WLAN, do not seem to provide better cost efficiency than standard hierarchical cell structures in single-access systems. Instead, multi-access solutions have to be motivated by other factors like peak data rates and spectrum availability.