Virtual Sensor Networks (VSNs) is an emerging form of collaborative Wireless Sensor Networks (WSNs). VSNs support collaborative, resource efficient, and multi-purpose WSNs. These networks may involve dynamically varying subset of sensor nodes and/or users. VSNs are useful in three major classes of applications:
Geographically overlapped applications
e.g., monitoring rock slides and animal crossing within a mountainous terrain. Different types of devices that detect these phenomena can relay each other for data transfer without having to deploy separate networks. Here the advantage is saving in hardware cost.
VSNs are useful in logically separating multi-purpose sensor networks
e.g., smart neighborhood systems with multifunctional sensor nodes. In stead of traditional WSNs that runs one single applications, VSN enabled nodes run multiple applications
VSNs can be used in certain dedicated applications
e.g., to enhance efficiency of a system that track dynamic phenomena such as subsurface chemical plumes that migrate, split, or merge. Such networks may involve dynamically varying subsets of sensors. Here the advantage is the ability to connect right set of nodes at the right time.
A VSN can be formed by providing logical connectivity among collaborative sensors. Nodes can be grouped into different VSNs based on the phenomenon they track (e.g., rock slides vs. animal crossing) or the task they perform. VSNs are expected to provide the protocol support for formation, usage, adaptation, and maintenance of subset of sensors collaborating on a specific task(s). VSNs should make efficient use of intermediate nodes, networks, or other VSNs to deliver messages across members of a VSN. The main idea of VSNs is the collaboration and resource sharing. By doing so nodes achieve application objectives in a more resource efficient way.
So far we have simulated a top-down clustering scheme, 3 cluster tree based routing schemes, VSN self organization scheme on top of the cluster tree, and VSN based subsurface chemical plume monitoring system. Currently we are working on random routing, virtual coordinates, and VSN support functions.
D. C. Dhanapala and A. P. Jayasumana, "CSR: Convex Subspace Routing Protocol for WSNs," Proc. 33rd Annual IEEE Conference on Local Computer Networks, Switzerland, Oct. 2009.
P. Loden, Q. Han, L. Porta, T. Illangasekare, and A. P. Jayasumana, "A Wireless Sensor System for Validation of Real-time Automatic Calibration of Groundwater Transport Models," The Journal of Systems and Software, Elsevier, vol. 82, 2009, pp. 1859-1868.
H.M.N.D. Bandara, A. P. Jayasumana and T. H.
Illangasekare, "Cluster Tree Based Self Organization
of Virtual Sensor Networks," IEEE Globecom Workshop
on Wireless Mesh and Sensor Networks, New Orleans, LA, Nov.
D.C. Dhanapala, "On performance of random routing and virtual coordinate based routing in wireless sensor networks," M.S. Thesis, Department of Electrical and Computer Engineering, Colorado State University, 2009.
Simulator supports several features including SHC, HHC, tree optimization, message collisions, low/high power communication between cluster heads, RSSI based clustering, secure backbone, VSN formation, etc. Code to generate topology, keys, and analyze data is also provided.