(刷卡验证).ppt

1、ActiveBadge:1 WirelessNet Tseng,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 -,ActiveBadge:2 WirelessNet Tseng,How Do We Locate People?,Goal: efficient location a

2、nd 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:,ActiveBadge:3 WirelessNet Tsen

3、g,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,Active Badge Active Badge . Active Badge,Badge Sensor Badge Sensor,Serv

4、er/Application,network,wireless IR,ActiveBadge:4 WirelessNet Tseng,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.

5、 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.,ActiveBadge:5 WirelessNet Tseng,Badge Sensor and Networking,many sensors c

6、an 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 netwo

7、rking: 4 wires (2 for power supply, 1for control/poll, and 1 for data) conform to telephone cabling, thus easy for cabling and low-cost,ActiveBadge:6 WirelessNet Tseng,Badge Sensor and Networking (cont.),fig. 2,ActiveBadge:7 WirelessNet Tseng,Application: Active Office,a system integrating name loca

8、tion information phone network commands supported: FIND (name) WITH (name): who are the other badges nearby name now LOOK (location) NOTIFY (name) HISTORY (name),ActiveBadge:8 WirelessNet Tseng,Active Office Display Screen,Fig. 3,ActiveBadge:9 WirelessNet Tseng,Benefits of Active Office,automatic re

9、-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,ActiveBadge:10 WirelessNet Tseng,Conclusions,Future: extend to 2-way communication Future: combine with moti