Candidate Talk: ZebraNet and Beyond: Collaboration in Sparse Mobile Networks

  • Pei Zhang | Princeton University

With the proliferation of sensor networks, the ever expanding variety of applications has driven researchers to focus not only on fixed networks, but also on mobile networks. For many reasons, both technical and logistical, such networks will often be very sparse for all or part of their operation, necessitating their need to function as disruption-tolerant networks (DTNs).

In this talk, I will discuss collaboration techniques for both data gathering and parameter estimation in sparse DTNs. I will first introduce the ZebraNet system, a sparse mobile network we designed and deployed for animal tracking in areas with scarce infrastructure, and its collaborative data gathering technique for efficiently collecting animal position data.

I will then devote the rest of the talk to my dissertation work that extends the collaborative technique to dynamic information sharing. I will in particular focus on LOCALE, a collaborative localization technique for low-density networks without per-node GPS. Due to the very sparse nature of DTNs, instant information sharing is impossible. The key novelty of LOCALE is that nodes not only collaborate with occasional neighbors, but also actively predict their own position through inexpensive movement tracking during periods of disconnection. Thus, LOCALE enables “real-time” collaborative location estimation even when networks are very sparse. I will present simulation and implementation results that show its accuracy, energy savings, and infrastructure savings compared to other prior techniques. For example, LOCALE produces accurate location estimations with 150X power savings over per-node GPS.

Speaker Details

Pei Zhang received his Bachelor’s degree with honors from California Institute of Technology in 2002, and he is expecting a Ph.D. degree in Electrical Engineering from Princeton University in June 2008. While at Princeton University, he developed the ZebraNet system, a hardware/software sensor system dedicated to sparse mobile networks.Being the first deployed, wireless, ad-hoc, mobile sensor network, his work was proven during its deployments at Sweetwater’s Game Reserve in central Kenya. In addition, his work received various awards, including the 3rd International Low Power Design Contest ACM/IEEE International Symposium on Low-Power Electronics, as well as the Design and the Global Photonics Energy Corporation’s (GPEC) Edith and Martin B. Stein Solar Energy Innovation Award. His primary research interest is in embedded systems, with a special focus on mobile systems (sensor networks, ubiquitous computing). He is especially interested in developing practical solutions to problems involving variation and uncertainty in mobile networks.

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