Localized Distance-Sensitive Service Discovery in Wireless Sensor and Actor Networks

We formalize the distance-sensitive service discovery problem in wireless sensor and actor networks, and propose a novel localized algorithm, iMesh. Unlike existing solutions, iMesh uses no global computation and generates constant per-node storage load. In iMesh, new service providers (i.e., actors) publish their location information in four directions, updating an information mesh. Information propagation for relatively remote services is restricted by a blocking rule, which also updates the mesh structure. Based on an extension rule, nodes along mesh edges may further advertise newly arrived relatively near service by backward distance-limited transmissions, replacing previously closer service location. The final information mesh is a planar structure constituted by the information propagation paths. It stores locations of all the service providers and serves as service directory. Service consumers (i.e., sensors) conduct a lookup process restricted within their home mesh cells to discover nearby services. We analytically study the properties of iMesh including construction cost and distance sensitivity over a static network model. We evaluate its performance in static/dynamic network scenarios through extensive simulation. Simulation results verify our theoretical findings and show that iMesh guarantees nearby (closest) service selection with very high probability, Gt99 percent (respectively, Gt95 percent).

1 Introduction

A Wireless sensor network is a collection of microsized and resource-constrained wireless sensing devices, sensors, deployed in a region of interest for surveillance purpose. Traditionally, it is a data gathering network where nodes are stationary and responsible only for sampling their surroundings and reporting to predefined data sinks. As hardware technology advances, it is now evolving toward service-oriented wireless sensor and actor network (WSAN) [1], [25]. In WSAN, actor nodes are able to interact with the physical world. They may be static or mobile. Examples of static actors are sprinklers attached on the ceiling of an office room and sound-sensitive lights installed in a dark hallway.