Motion-Indicated Interest Dissemination With Directional Antennas for Wireless Sensor Networks With Mobile Sinks

Introducing mobile sinks into wireless sensor networks improves energy efficiency and prolongs network lifetime. Mobile sinks are also in demand in many sensor network applications. However, sink mobility causes frequent topology changes, resulting in high packet loss rate and poor energy efficiency. A directional-antenna-assisted reactive routing protocol, namely, interest dissemination with directional antennas (IDDA), is proposed to solve this problem. Different from traditional interest diffusion routing protocols, IDDA exploits the directional antenna on the mobile sink to prearrange interest dissemination along the direction of motion. The antenna directionality and the transmission power can indicate the motion of the mobile sink. An analytical model is established to calculate the optimal width of the antenna beam pattern and the optimal transmitting power. The multiple IDDA scheme, which is an enhancement to IDDA that can further improve network performance, is also presented. Extensive simulation results show that IDDA outperforms the traditional directed diffusion protocol, which guarantees that IDDA can be applied to sensor networks with highly mobile data sinks.