Modular wireless mass evacuation notification system

• US 10,477,477 B2
• Filed: 02/05/2019
• Issued: 11/12/2019
• Est. Priority Date: 09/09/2014
• Status: Active Grant

• Current Assignee: Johnson Controls Fire Protection LP (Johnson Controls International plc)
• Original Assignee: Johnson Controls Fire Protection LP (Johnson Controls International plc)
• Inventors: Chiarizio, Martin A., Feltham, Robert
• Primary Examiner(s): McNally, Kerri L
• Application Number:
  US16/267,448
• Publication Number:
  US 20190174417A1
• Time in Patent Office: 280 Days
• Field of Search: 34053916
• 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 determining a system maximum cumulative propagation delay time value for wireless base units, comprising:

the wireless base units determining maximum cumulative propagation delay time values for their subnets;

the wireless base units sending the determined maximum cumulative propagation delay time values to an alarm panel; and

the alarm panel determining a system maximum cumulative propagation delay time value by comparing the maximum cumulative propagation delay time values received from the wireless base units.

2. A method as claimed in claim 1, further comprising the alarm panel sending a system status check to the wireless base units prior to the wireless base units determining the maximum cumulative propagation delay time values.

3. A method as claimed in claim 1, further comprising the wireless base units sending the determined maximum cumulative propagation delay time values within acknowledgement (ACK) messages to the alarm panel.

4. A method as claimed in claim 1, further comprising the alarm panel predicting system dynamics based on the determined system maximum cumulative propagation delay time values.

5. A method as claimed in claim 1, further comprising the alarm panel including time stamps indicating message transmission time and a cumulative propagation delay value.

6. A method as claimed in claim 1, further comprising the wireless base units receiving time stamps in messages and comparing the received time stamps to local times kept by the wireless base units and based on the cumulative propagation delay values.

7. A method as claimed in claim 1, further comprising some of the wireless base units retransmitting messages from the alarm panel.

8. A method as claimed in claim 1, further comprising, the wireless base units, prior to retransmission, adding to the cumulative propagation delay value along with the original transmission timestamp.

9. A method as claimed in claim 1, further comprising each of the subnets having different repeater levels synchronizing to a system time of the alarm panel by compensating for processing time of each of the repeater levels.

10. A method as claimed in claim 1, further comprising the alarm panel broadcasting a system beacon, including a system time stamp, at regular intervals.

11. A method as claimed in claim 1, wherein the wireless base units correct their individual time to match a global system time based on timestamps from the alarm panel.

12. A method as claimed in claim 1, wherein the system maximum cumulative propagation delay time value is determined based on received cumulative propagation delay times of repeaters and the base units.

13. A method as claimed in claim 12, wherein the repeater units send to the alarm panel cumulative propagation delays for the devices in their subnets.

14. A method as claimed in claim 1, wherein during system diagnostics, known delay and calculated delay are compared to determine how system dynamics might be affected by wireless traffic and local wireless conditions.

15. A notification system, comprising:

alarm panel; and

wireless base units determining maximum cumulative propagation delay time values and sending the determined maximum cumulative propagation delay time values to the alarm panel,

wherein the alarm panel determines a system maximum cumulative propagation delay time value by comparing the maximum cumulative propagation delay time values received from the wireless base units.

16. A system as claimed in claim 15, wherein the alarm panel sends a system status check to the wireless base units prior to the wireless base units determining the maximum cumulative propagation delay time values.

17. A system as claimed in claim 15, wherein the wireless base units send the determined maximum cumulative propagation delay time values within acknowledgement (ACK) messages to the alarm panel.

18. A system as claimed in claim 15, wherein alarm panel predicts system dynamics based on the determined system maximum cumulative propagation delay time values.

19. A system as claimed in claim 15, wherein the alarm panel sends time stamps indicating message transmission time and a cumulative propagation delay value.

20. A method for scheduling an event for wireless base units, comprising:

an alarm panel determining a system maximum cumulative propagation delay time value;

the alarm panel receiving an alarm turn on signal for an event;

the alarm panel calculating a scheduled event time by summing the current time with the determined system maximum cumulative propagation delay time value;

the alarm panel broadcasting the scheduled event time to the wireless base units; and

the wireless base units executing the event in sync with each other based on the scheduled event time.