Scalability of wireless LAN systems in the unlicensed 17 GHz frequency band

Wireless LAN systems are increasingly used in offices, hotels and public places to provide high-speed wireless access for portable computers and other mobile devices. Wireless LAN are relatively cheap, easy to install and require no license for operating a network. Current systems mostly use the 2.4 or 5 GHz frequency bands, where propagation conditions yield large cells and hence allow covering sizable areas with only a few access points (AP). If wireless traffic grows and the network becomes congested, either the cell size must be reduced or an overlay network in another frequency band deployed so that the increased capacity demand can be met In this paper, the second alternative is considered and the performance of a network operating at 17 GHz studied, since the band between 17.1 and 17.3 GHz was suggested for operating unlicensed wireless LAN. The performance of a proposed system is studied in three typical usage scenarios, a large shopping mall, an office setting and a campus area. Specific attention is paid to reducing installation costs. A method for simplifying the network planning is proposed and the influence on the system performance studied. Simulation results show that the system capacity, ie, the achievable data rate per user, increases almost linearly with the infrastructure density (number of AP installed per user). The proposed user-deployment approach, where the AP are set up by the users themselves, minimizes the network-planning overhead and causes only a relatively small performance loss