The ZebraNet Wild Life Tracker

Department of Electrical Engineering

Princeton University

Road Map

• Background

• ZebraNet: Problem Statement

• ZebraNet Design Details

• Protocol Design Tradeoffs

• Current Status

Background

• Sensor nets

• In areas without cellular coverage

• Using peer-to-peer communication

• With “ad hoc” methods for discovering network routes and keeping them up to date

ZebraNet• Biologists want to track animals

• ZebraNet: Wireless ad hoc network of zebras…– Intelligent tracking collars placed on s

ampled set of zebras– Sensor network: data collected includ

es GPS position info, temperature,

Data to track: What are the sensors in this net?

• Current– GPS position sample

every 3 minutes– Sun/Shade indication– Detailed position

sampling: Standing still or moving? Speed? “Step rate”.

• Future– Head up or down:

“bite rate”– Body temperature– Heart rate– Interactions with oth

er species– ZebraCam

Challenge

• Need sufficiently long range• Power generation & storage:

Power efficiency• serious bandwidth and

computational needs • Reliability & fault tolerance• Good physical design for

ruggedness• Variable frequency for use in US &

Kenya

ZebraNet Block Diagram

ZebraNet sensor• Weight: 1090 grams (2.4lbs)• Designed to operate for 5 days without

solar recharge• Energy saving tricks

• Baby picture

Basic Operation System

• Nodes collect logs of GPS position and other information.

• Peer-to-peer communication aggregates data back to researcher base station

• Research station is not fixed. Rather, it moves and is only intermittently available

Protocol tradeoff

• Flooding: Every 3 minutes, zebras look for other zebras in range. Send to everyone they find.

• History-Based: Every 3 minutes, zebras look for others in range. Of the ones found, only send to one: the one with the best success rate at delivering data.

Current Status

• January 2-24, 2004: ZebraNet heads to Kenya for its first test deployment! They were at the Mpala Research Centre and deploying nodes on zebras at the Sweetwaters Reserve.