PASSIVE WIRELESS SYSTEM

• US 20100127837A1
• Filed: 11/24/2008
• Published: 05/27/2010
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Addy, Kenneth L.
• Granted Patent: US 8,552,838 B2
• Time in Patent Office: Days
• US Class Current: 340/10.340
• CPC Class Codes: G08B 13/24 by interference with electromagnetic field distribution

Abstract

A passive wireless system for monitoring a protected area. The passive wireless system comprises at least one passive sensor for sensing an event, a reader for receiving signals from the at least one passive sensor, a plurality of exciters disposed within the protected area for transmitting a radio frequency pulse at a variable time interval to the at least one passive sensor, and a controller for controlling each of the plurality of exciters to transmit the radio frequency pulse at the variable time interval. The radio frequency pulse powers the passive sensors.

Claims

1. A passive wireless system for monitoring a protected area comprising:

at least one passive sensor for sensing an event;

a reader for receiving signals from the at least one passive sensor;

a plurality of exciters disposed within the protected area for transmitting a radio frequency pulse at a variable time interval to the at least one passive sensor to power the at least one passive sensor; and

a controller for controlling each of the plurality of exciters to transmit the radio frequency pulse at the variable time interval.

2. The passive wireless system of claim 1, wherein each of the plurality of exciters is integrated into a security system device.

3. The passive wireless system of claim 2, wherein the security system device is a security system keypad.

4. The passive wireless system of claim 2, wherein the security system device is a wired security system sensor.

5. The passive wireless system of claim 1, wherein the variable time interval is distinct for each of said plurality of exciters.

6. The passive wireless system of claim 1, wherein the controller selects the variable time interval depending on a location of each of the plurality of exciters within the protected area.

7. The passive wireless system of claim 1, wherein the controller selects the variable time interval depending on a relative location of each of the plurality of exciters to each of the at least one passive sensor.

8. The passive wireless system of claim 1, wherein the controller selects the variable time interval depending on a type of each of the at least one passive sensor, said type being a magnetic contact motion sensor, heat detector, acoustic detector and asset sensor.

9. The passive wireless system of claim 1, wherein the controller selects the variable time interval depending on a status of said passive wireless security system, said status being disarmed, armed-stay and armed-away.

10. The passive wireless system of claim 1, wherein the controller selects the variable time interval depending on a location of each of the at least one passive sensor within the protected area.

11. The passive wireless system of claim 1, wherein the controller selected the variable time interval depending on a priority of each of the at least one sensors.

12. The passive wireless system of claim 1, wherein the controller sets the variable time interval for each exciter to be offset from each other.

13. A wireless communication method between at least one passive sensor and a wireless reader comprising the steps of:

assigning a transmission time for each of a plurality of wireless exciters;

transmitting control signal including the assigned transmission time to each of the plurality of wireless exciters; and

transmitting, during the assigned time, a pulse power signal to the at least one passive sensor, wherein the at least one passive sensor is powered by the pulse power signal.