A methodology for WLAN planning under 3G network

This paper deals with a practical approach for planning WLAN hotspots to be underlaid within an existing 3G network. Given the number of access points (APs) and access routers (ARs), their locations, call handling capacities of ARs as well as serving GPRS Support Nodes (SGSNs), intra-WLAN handoff costs, and 3G/WLAN inter-system handoff costs, an important consideration for a mobile telecom service provider (MTSP) is to identify: (a) the APs to be connected to the corresponding ARs, and (b) the ARs to be connected to the corresponding SGSNs in a cost effective manner. In this work, while planning a WLAN roll-out for an MTSP, we present an integrated approach based on the minimization of total system cost. Using a heuristic strategy, the planning attempts to determine simultaneously an optimal partitioning of APs with respect to the given set of ARs in each hotspot and also the assignment of ARs to SGSNs over the complete service area. Our study shows that acceptable results are achievable with a reasonable computational effort, which supports the engineered planning of a tightly coupled WLAN/3G integration.