Coverage Estimations in a WLAN-based Open Broadband Access Network (OBAN)

The main idea of the OBAN concept is that the future deployment of broadband access lines and wireless LANs will have so much excess capacity, beyond what will be utilized by the host households, that it also can accommodate public wireless access services. The purpose of this paper is to analyse the viability of this idea with respect to wireless coverage in some typical scenarios. A model for estimating coverage in single and triple frequency wireless networks based on IEEE 802.11g WLAN is presented. A model for interference is established distinguishing between two types of interference, one present between near neighbours leading to reduced traffic capacity due to the CSMA/CA protocol of the WLAN, and one physical layer interference which will be present between far neighbours, beyond detection range. This latter co-channel interference (CCI) leads to reduced coverage compared to single cell operations and the effects are investigated here. A method of using these results as input to traffic simulations is shown. The analysis shows that severe range reductions will occur even for low traffic in the network. Results for coverage in % are given for three different scenarios.