LOCUST:

An Experiment in Private Localization


At the MIT Media Lab, we are constructing a network of individuals with wearable computers . Some of these individuals employ the use of an agent to assist with the organization of the increased information content inherent in wearable computing. As an additional input to this agent, a system of location-based messaging has been developed.

A full network of infrared beacons has been developed using the iRX 2.0 printed circut board, developed by R. Poor in the Personal Information Architecture group, fitted with a PIC16C84, an IR LED, and an IR receiver. These beacons are placed strategically throughout the lab (namely in areas of transition such as doorways) and continuously bleat out their position (room number). Each locust is powered by one All Electronics 9V solar cell positioned near a flourescent light. A second iRX 2.0 with PIC, Maxim233 , infrared receiver, and RS-232 serial port acts as a receiver for the beacons. It translates the IR TTL data to a RS-232 signal which is fed to a wearable computer via a serial port. In this manner, the agent knows it's current location within the building.

This information is useful for several applications. First, the computer can put date, time, place stamps on information, for ease of retrieval later. Second, the user can broadcast (or chose not to) his/her location to specific groups or individuals. Thus, the wearable knows where it is, but the lab doesn't know where the wearable is. Finally, the agent can use this information to assist in it's decision making processes. For example, the agent holds-off notifying you of the arrival of a new piece of junk e-mail until after you leave the conference room.

The second feature of this system is the upload feature. Under this paradigm the user would be notified of any place-based messages which had been left. Tagging places with messages is useful in a variety of circumstances, from leaving a "will return at 1pm" notice near your desk at lunchtime, to reminding people that the stairs are especially slippery today. This messaging system uses the IR transmition to download a signal which displays a text message to the user. In this manner messages can be left and retrieved anywhere a LOCUST device is.

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Contact by e-mail kirsch@mit.edu.