Mobile terminal interfaces management for energy efficiency

Coexisting heterogeneous wireless access networks are nowadays common in many places, and growing fast. This, together with the increasing service demand from nomad end-users, indicates that a re-assessment of current mobile terminals´ management mechanisms, namely concerning QoS, energy efficiency, etc., is necessary, as well as more suitable access selection polices. The IEEE 802.21 standard provides link layer intelligence as well as associated network information to the layers above in order to optimize handovers between heterogeneous networks, of different technologies, such as Wi-Fi, 3GPP and WiMAX. It is key to manage efficiently the available interfaces embedded in the modern mobile terminals, not only to appropriately provide the requested services to the end-user, but also to do that in an energy efficient way. This will allow extending the battery life of the mobile terminal integrating multiple wireless interfaces, and ultimately allowing higher mobility to the nomad user. A customized implementation of the IEEE 802.21 standard was used in the work presented this paper. This simulation platform was developed in ns-2, and integrates an energy saving mechanism proposed for the management of the available wireless interfaces in mobile terminals, exploiting positioning information.