MODULAR WIRELESS MASS EVACUATION NOTIFICATION SYSTEM

• US 20170301217A1
• Filed: 06/29/2017
• Published: 10/19/2017
• Est. Priority Date: 09/09/2014
• Status: Active Grant

• Current Assignee: Johnson Controls Fire Protection LP (Johnson Controls International plc)
• Original Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Inventors: Chiarizio, Martin A., Feltham, Robert
• Granted Patent: US 10,212,664 B2
• Time in Patent Office: Days
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 17/10 Actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
• CPC Class Codes: G08B 25/007 Details of data content structure of message packets; data protocols
• 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: G08B 27/00 Alarm systems in which the alarm condition is signalled from a central station to a plurality of substations
• CPC Class Codes: G08B 27/008 with transmission via TV or radio broadcast
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0238 where the received signal is an unwanted signal, e.g. interference or idle signal
• CPC Class Codes: H04W 56/0055 determining timing error of reception due to propagation delay
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Monitoring and mass notification systems, such as fire alarm systems, for use in occupied structures, and more particularly to wireless monitoring and mass notification systems include wireless base units that can be modular in design. This allows horns, mini horns, strobes, and audio messaging modules (e.g., speakers) to be physically plugged into the wireless base unit creating a unit with the appearance of a single physical unit. Preferably standardized plugs are used. In some cases, visual and audio modules (i.e., notification devices) have their own battery pack or external power interface. Each wireless base unit can optionally function as a repeater if it has dual transceivers (master transceiver and slave transceiver).

Claims

1. A method for synchronizing a wireless base unit, comprising:

a control unit transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value;

a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value.

2. The method of claim 1, further comprising the wireless base unit recording a receipt time based on a local time and processing the system message.

3. The method of claim 1, further comprising the wireless base unit calculating a processing time delay value based on a difference between the receipt time and the local time after processing the system message.

4. The method of claim 3, further comprising the wireless base unit determining the new cumulative propagation delay time value by summing the processing time delay value with the received cumulative propagation delay time value and the control unit transmission time.

5. The method of claim 1, further comprising the wireless base unit updating the local time of the wireless base unit based on the new cumulative propagation delay time value.

6. The method of claim 1, further comprising:

the control unit sending a time-correcting system beacon having a global system time to the wireless base unit; and

the wireless base unit updating the local time to match the global system time prior to the wireless base unit receiving the system message.

7. The method of claim 6, wherein the time-correcting system beacon is sent every second.

8. The method of claim 6, wherein the global time is within a system timestamp having a resolution between about 100 microseconds and about 1.0 millisecond.

9. The method of claim 1, further comprising the wireless base unit forwarding the system message to another wireless base unit via wireless links, wherein the forwarded system message includes a new timestamp having the new cumulative propagation delay time value.

10. A monitoring and mass notification system, comprising:

a control unit for transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value; and

a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value.

11. The system of claim 10, wherein the wireless base unit records a receipt time based on a local time and processing the system message.

12. The system of claim 10, wherein the wireless base unit calculates a processing time delay value based on a difference between the receipt time and the local time after processing the system message.

13. The system of claim 12, wherein the wireless base unit determines the new cumulative propagation delay time value by summing the processing time delay value with the received cumulative propagation delay time value and the control unit transmission time.

14. The system of claim 10, further comprising the wireless base unit updating the local time of the wireless base unit based on the new cumulative propagation delay time value.

15. The system of claim 10, wherein the control unit sends a time-correcting system beacon having a global system time to the wireless base unit and the wireless base unit updates the local time to match the global system time prior to the wireless base unit receiving the system message.

16. The system of claim 15, wherein the time-correcting system beacon is sent every second.

17. The system of claim 15, wherein the global time is within a system timestamp having a resolution between about 100 microseconds and about 1.0 millisecond.

18. The system of claim 10, wherein the wireless base unit forwards the system message to another wireless base unit via wireless links, wherein the forwarded system message includes a new timestamp having the new cumulative propagation delay time value.