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The Active Badge Location System. R. Want, A. Hopper, V. Falcao, and J. Gibbon in ACM Trans. on Information Systems, Vol. 10, No. 1, Jan. 1992, pp. 91-102 -- presented by Yu-Chee Tseng --. How Do We Locate People?. Goal: efficient location and coordination of staff in a large organization.
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The Active Badge Location System R. Want, A. Hopper, V. Falcao, and J. Gibbon in ACM Trans. on Information Systems, Vol. 10, No. 1, Jan. 1992, pp. 91-102 -- presented by Yu-Chee Tseng --
How Do We Locate People? • Goal: efficient location and coordination of staff in a large organization. • Ex: location of doctors, staffs, and patients in a hospital. • Existing Solutions: • broadcasting • a phone to call several possible numbers • a beeper with audible signal or call-back number • key card (刷卡驗證) for access control:
Active Badge System • each badge that can automatically emit a unique code • a network of sensors placed around the building • a master server, also connected to the network, makes the location information available to outside world wireless IR network Active Badge Active Badge ... Active Badge Badge Sensor Badge Sensor Server/Application
Active Badge Design (cont.) • Pulse-width modulated infrared (IR) signaling: • transmission range: 6 meters • can reflect by office partitions, but will not penetrate like radio signals • emits a unique code every 15 sec, for about 1/10 sec. • Quite power-saving. Can last for > 1 year. • Has a light detector. On dark (e.g., badge placed in a drawer), increase emitting period. Can last for > 4 years. • Good performance to wear on breast pocket; OK to wear on belt or waist.
Badge Sensor and Networking • many sensors can be installed, as the unit cost is very low. • can be placed on walls, entrances, exits, corridors, public areas, etc. • sensor ---(RS232)---> computer ---(Ethernet)--> server • up to 128 sensors can be supported by a computer • a FIFO buffer can store 20 badge data items (to avoid network congestion) • sensor networking: • 4 wires (2 for power supply, 1for control/poll, and 1 for data) • conform to telephone cabling, thus easy for cabling and low-cost
Application: Active Office • a system integrating • name • location information • phone network • commands supported: • FIND (name) • WITH (name): who are the other badges nearby name now • LOOK (location) • NOTIFY (name) • HISTORY (name)
Active Office Display Screen • Fig. 3
Benefits of Active Office • automatic re-direction of incoming calls • relieve burden of receptionist • you have less chance of missing some important calls you are waiting for • receptionist can easily tell whether a person is in or not • easier when calling for a meeting • easy to identify visitors to our organization
Conclusions • Future: • extend to 2-way communication • Future: combine with motion detector • can provide high security • if a person moves without active badge being detected, an alarm can be alerted. • Mobile 911 (emergency call)