Robust and timely communication over highly dynamic sensor networks

Abstract

Highly dynamic sensor networks, such as mobile robotic sensor networks, have been applied in various kinds of application scenarios such as real-time planet exploration and deep-ocean discovery. In these types of networks, mobility and energy management protocols change the connectivity among the neighboring nodes quickly. Traditional state-based protocols, designed for static and/or low-mobility networks, suffer excessive delay in updating their routing or neighborhood tables, leading to severe packet loss and communication delay in the highly dynamic situations. To provide robust and timely communication, we exploit the concept of Lazy-Binding to deal with the elevated network dynamics. Based on this concept and the knowledge of the node positions, we introduce Implicit Geographic Forwarding (IGF), a new protocol for highly dynamic sensor networks that is altogether state-free. We compare our work against several typical routing protocols in static, mobile and energy-conserving networks under a wide range of system and workload configurations. In the presence of mobility and other dynamics, IGF achieves as much as 10 times improvement in the delivery ratio and significant reduction in both the end-to-end delay and control overhead. In addition to extensive simulations, we also implement and evaluate the IGF protocol on the Berkeley mote platform.