Energy-aware routing optimization in ad-hoc wireless networks under QoS constraints

In the design of modern mobile wireless networks the effort for performance improvement has to be balanced with the effort in more effective energy management strategies. In fact, the capacity of batteries is not increasing as new devices and multimedia applications requires. In this paper a new approach to routing optimization in ad-hoc wireless networks supporting multimedia communication is investigated. It exploits an energy model for the radio interface and cross-layer information to dynamically determine routing paths connecting wireless nodes, in order to reduce energy consumption and prolong network lifetime, while preserving quality of service. A network architecture based on a modified 802.11a wireless physical interface with multi-channel capability is considered. We investigate a multi-hop environment where network devices collect cross- layers information and periodically update a central repository located on a network node elected as network coordinator. The coordinator exploits the recorded information to provide best quality routing paths to devices that need to send sensible data over the network. We propose here an algorithm for routing path optimization and compare the optimized strategy with a reference implementation of the OLSR routing protocol. The numerical results show benefits in terms of increased network life-time.