Efficient WLAN Discovery Schemes Based on IEEE 802.21 MIH Services in Heterogeneous Wireless Networks

Discovering currently available radio access networks (RANs) is one of the most challenging issues in the heterogeneous wireless network environment. Especially, discovering WLANs, which support high data rates but have limited service coverage, has a significant effect on the energy consumption of multi-mode terminals (MMTs). In this paper, we propose three WLAN discovery schemes which are based on the upcoming IEEE 802.21 standards. In the proposed schemes, a MMT exploits the information on neighboring WLANs from a MIH information server to discover available WLANs as soon as possible while minimizing energy consumption. Our simulation results show that the proposed schemes can enhance the performance of MMTs in terms of energy consumption and the detection time of WLANs compared to conventional WLAN discovery schemes.