Route adaptation in response to changes in network activity in mobile frequency-hop networks

An adaptive routing protocol is defined and evaluated that uses a measure of the network activity in making routing decisions. The distributed routing protocol is designed to conserve energy when possible without increasing delay or decreasing packet success probability. It operates in a frequency-hop network in which mobile radios employ an adaptive-transmission protocol. Each radio monitors the amount of time that it is transmitting or receiving, and it uses this information to calculate an on-air ratio. This on-air ratio provides each radio with a measure of its activity level, which is used by a radio to determine when to adapt its routing protocol. When the network activity is low, a radio strives to employ low-energy links in forwarding packets. As the activity level increases, the routing protocol adapts by employing more high-quality routes in an effort to maintain low delay and high packet success rate. Our simulation results for mobile networks show that routing based on network activity levels provides energy savings when the opportunity exists, yet it achieves low delay and high packet success probability.