The Design of an Interval Routing Enabled Publish/Subscribe Communications Protocol for Ad Hoc Sensor Networks

Sensor networks, due to their applicability, have been attracting a considerable amount of attention in the research community recently. The limited resources available for the sensors (like memory, energy, etc.) pose significant challenges in building routing infrastructures for sensor networks. The ad hoc nature of the sensor networks also present challenges in fault tolerance. This paper discusses the design of a Publish/Subscribe routing algorithm in the ad hoc sensor network environment. The discussion explores the limitations and hence challenges posed by the ad hoc nature of the sensor networks. The routing algorithm relies on a distributed broker-tree infrastructure. The infrastructure supports data aggregation, loop-free routing and faulttolerance for Publish/Subscribe in ad hoc networks. A potential drawback of scalability in the algorithm in terms of routing-table size is pointed out. Correspondingly, a proposal for an alternative infrastructure based on interval routing is made. Interval routing is a memory efficient routing methodology in distributed networks that leads to routing tables of size O(d), where d is the number of immediate neighbors of each node in the network. Interval routing is static in nature, and hence needs some add-on services to be useful in the ad hoc environment of the sensor networks. The services of neighbor detection, leader election, and support for fault detection are used in this context. The alternative proposed has been primarily inspired by the limited resource availability challenge posed by the sensor networks.