One of the major challenges to realize the Internet of Things is to support IP mobility for the large amount of connected entities when they move between different locations and access methods. Current solutions for mobility are host centric, requiring support from the infrastructure, or breaks backwards compatibility, which will take a long time or high economic motivation to implement. Solutions for context information exchange are created for specific, small, or localized scenarios with centralized coordination that do not scale well. There is therefore a need for a solution which both scales well, and support IP mobility, without additional demands on current or future Internet infrastructure.We propose the use of a dual-overlay network structure for both information dissemination and as an alternative to current IP mobility technologies. It separates identities from location by introducing a second overlay network where the identity-to-location association is stored. We show analytically that the proposed solution provide logarithmic latency for localization and reduces the overall workload when the number of sensors per host increases beyond seven, with a workload reduction of 15 percentage points at fifteen sensors per host.
Traffic load is typically not evenly distributed over the sensor nodes in a wireless sensor network (WSN). Understanding the traffic load distribution can guide the network-wide energy allocation, the design of routing algorithms, and the optimization of the node deployment in WSNs. This article considers a dense WSN with nodes uniformly distributed in a disk sensing area, where the expected traffic load distribution over the sensor nodes as a function of their distance from the sink has been derived. Further, the effects of the network scale and routing strategy on traffic load distribution are also investigated. The expected traffic loads beared by individual sensor nodes are found to be in direct proportion to the radius of the network and inversively proportional to the routing hop length but it is independent of the network density. In addition, a heuristic multipath routing algorithm is found to be capable of reducing the traffic load variance experienced by neighboring or symmetrically deployed sensor nodes. The results presented in this article are verified through extensive simulation experiments. © 2011 ACADEMY PUBLISHER.