Failsafe signal transmission for wireless sensor mesh

• US 8,552,857 B2
• Filed: 10/14/2010
• Issued: 10/08/2013
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Berezowski, Andrew G., Rauworth, Tim, Kore, Vinayak Sadashiv
• Primary Examiner(s): Swarthout, Brent
• Application Number:
  US12/904,382
• Publication Number:
  US 20120092159A1
• Time in Patent Office: 1,090 Days
• Field of Search: 340/539.22, 340/286.05, 340/539.26, 340/506, 370294-458, 370/913, 370/915, 375/356, 455/502, 455/561
• US Class Current: 340/539.22
• CPC Class Codes: G08B 25/009 Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

An apparatus is provided. The apparatus includes a plurality of transceivers arranged in a mesh network that each synchronously communicate with at least one other of the plurality of transceivers in an assigned slot of a TDMA channel, at least a first of the plurality of transceivers asynchronously transmitting a priority message on a priority channel that is different than the TDMA channel and at least a second of the plurality of transceivers that detects an information content of the asynchronous priority message on the priority channel and retransmits the detected information content synchronously on the TDMA channel to a third transceiver of the plurality of transceivers.

Claims

1. An apparatus comprising:

a control panel of a security system;

a plurality of transceivers of the security system, wherein during start up of the security system, each of the plurality of transceivers listen for wireless transmissions from the control panel and from other transceivers of the plurality of transceivers, wherein at least some of the plurality of transceivers detect wireless transmissions from the control panel and each establishes itself as a hub transceiver through which wireless transmissions from other transceivers that are further away and cannot detect the control panel are relayed to the control panel through the hub transceiver and visa versa, the at least some hub transceivers each synchronously communicate with the control panel of the security system in an assigned slot of a TDMA channel;

at least a first of the plurality of transceivers not able to detect the control panel asynchronously transmitting a priority message on a priority channel that is different than the TDMA channel; and

at least a second of the plurality of transceivers established as a hub transceiver that detects an information content of the asynchronous priority message on the priority channel and retransmits the detected information content synchronously on the TDMA channel to the control panel.

2. The apparatus as in claim 1 further comprising the first transceiver also transmitting the priority message on an assigned slot of the TDMA channel.

3. The apparatus as in claim 1 wherein at least some of the plurality of transceivers further comprise environmental sensors.

4. The apparatus as in claim 1 further comprising a a processor of each of the plurality of transceiver that couples the transceiver to the control panel via the TDMA channel either directly or through another of the plurality of transceivers.

5. The apparatus as in claim 4 further comprising a synchronization signal transmitted by the control panel to each of the plurality of transceivers either directly or through another of the plurality of transceivers.

6. The apparatus as in claim 4 further comprising a central monitoring station that receives alarm messages through the control panel from the plurality of transceivers.

7. A method comprising:

a control panel of a security system providing a TDMA communication channel having a plurality of slots for synchronous transmission of information from a plurality of transceivers of the security system;

the control panel providing at least one priority channel that is different than the TDMA channel for priority transmissions;

during start up of the security system, each of the plurality of transceivers listening for transmissions from the control panel and from other transceivers of the plurality of transceivers;

at least some of the plurality of transceivers detecting transmissions from the control panel and each establishing itself as a hub transceiver through which transmissions from other transceivers that are further away and cannot detect the control panel are relayed to the control panel through the hub transceiver and visa versa;

synchronizing each of a plurality of transceivers that detected the control panel with an assigned one of the plurality of slots;

one of the plurality of transceivers losing synchronization with the slots;

the one transceiver transmitting a signal asynchronously on the priority channel;

another of the plurality of transceivers established as a hub transceiver and synchronized with the slots detecting the asynchronously transmitted signal on the priority channel; and

the other transceiver re-transmitting the detected signal synchronously in the assigned one of the plurality of slots.

8. The method of claim 7 further comprising defining the plurality of transceivers as a fire alarm system.

9. The method as in claim 8 further comprising coupling at least one of the plurality of transceivers to a fire detector.

10. The method as in claim 9 wherein the control panel further comprises a fire alarm control panel detecting transmissions from the transceivers on the TDMA communication channel.

11. The method as in claim 10 further comprising a transmitter of the fire alarm control panel transmitting a synchronization signal for the benefit of the plurality of transceivers.

12. The method as in claim 11 further comprising assigning each of the plurality of transceivers to a different slot of the plurality of slots.

13. An apparatus comprising:

a control panel of a security system;

a plurality of environmental sensors of the security system wherein during start up of the security system, each of the plurality of environmental sensors listen for transmissions from the control panel and from other environmental sensors of the plurality of environmental sensors, wherein at least some of the plurality of environmental sensors detect transmissions from the control panel and each establishes itself as a hub environmental sensor through which transmissions from other environmental sensors that are further away and cannot detect the control panel are relayed to the control panel through the hub environmental sensors and visa versa, each of the plurality of environmental sensors that detect transmissions from the control panel is assigned to synchronously exchange a communicated signal within one of a plurality of slots of a TDMA channel and alternatively where not able to detect transmissions from the control panel to asynchronously transmit a signal within a priority channel that is different than the TDMA channel wherein each of the plurality of environmental sensors further comprise;

a first processor that detects asynchronous transmissions of information on the priority channel and retransmits the detected information synchronously in the assigned slot;

a second processor that detects loss of synchronization; and

a third processor that transmits an asynchronous signal in response to loss of synchronization on the priority channel.

14. The apparatus as in claim 13 further comprising an alarm system.

15. The apparatus as in claim 14 wherein the control panel further comprises a control panel that exchanges the communicated signals with the plurality of sensors through the slots.