WISE: energy-efficient interface selection on vertical handoff between 3G networks and WLANs

The integration of 3G networks and WLAN as complementary has begun to attract much attention in industry as well as academia. This topic is becoming a burning issue, and one of the key questions which it raises is how to support a seamless vertical handoff. This paper introduces a new interface selection algorithm for energy-efficient vertical handoff in tightly coupled systems capable of supporting seamless handoff. Our proposed scheme, Wise Interface Selection (WISE) switches the active network interface, after taking into consideration the characteristics of the network interface cards and the current level of data traffic, with the cooperation of the mobile terminals and network. Interface switching operates independently on both the downlink and the uplink for the purpose of energy conservation. We show through simulation that less energy is consumed with WISE than when only a 3G network or WLAN interface is used, resulting in a longer lifetime for the mobile terminals. In the case of TCP connections, additional throughput gain can also be obtained.