Wi-Fi mesh fire detection system

Patent metadata

Field	Value
Publication number	US-10588173-B2
Application number	US-201213531181-A
Country	US
Kind code	B2
Filing date	Jun 22, 2012
Priority date	Jun 22, 2012
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A Wi-Fi mesh fire detection system and methods therefor are provided. The system can include a plurality of access points, where each access point in the plurality of access points is wirelessly connected to at least two other access points in the plurality of access points. For example, a first access point can be assigned as a primary parent device to a third access point, and a second access point can be assigned as a secondary parent device to the third access point. The third access point can transmit a message to the secondary parent device when the third access point fails to confirm that the primary parent device successfully received the message transmitted by the third access point.

First claim

What is claimed is:

1. A system comprising:
a plurality of access points of a time-synchronized network,
wherein each of the plurality of access points is assigned at least one respective transmission time slot and at least one respective reception time slot,
wherein each of the plurality of access points postpones transmitting messages by entering a low power sleep state until its at least one respective transmission time slot and at least one respective reception time slot within the time-synchronized network occurs,
wherein each of the plurality of access points enters the low power sleep state at times outside of the at least one respective transmission time slot and the at least one respective reception time slot of a respective one of the plurality of access points,
wherein each of the plurality of access points is wirelessly connected to at least two other access points in the plurality of access points,
wherein a first access point in the plurality of access points is assigned as a primary parent device to a third access point in the plurality of access points,
wherein a second access point in the plurality of access points is assigned as a secondary parent device to the third access point,
wherein the third access point determines whether the third access point has a transmission message to transmit during the at least one respective transmission time slot,
wherein the third access point performs a first attempt to transmit the transmission message to the primary parent device when the third access point determines that the third access point has the transmission message to transmit during the at least one respective transmission time slot,
wherein the third access point transmits the transmission message to the secondary parent device when the third access point determines that the third access point failed to receive a first acknowledgement message from the primary parent device within a predetermined period of time in response to the first attempt,
wherein the third access point determines whether the third access point received a second acknowledgement message from the secondary parent device before returning to the low power sleep state, and
wherein the second acknowledgement message indicates that the secondary parent device successfully received the transmission message.

2. The system as in claim 1 wherein at least one of the plurality of access points includes at least one of a wireless sensor, a pull station, and an actuator.

3. The system as in claim 1 wherein each of the plurality of access points is time synchronized with one another.

4. The system as in claim 1 wherein each of the plurality of access points includes a respective radio that is adapted to communicate compliant with an IEEE 802.11 standard.

5. A method comprising:
assigning a respective primary parent device to each access point of a plurality of access points of a time-synchronized network in a fire control system;
assigning a respective secondary parent device to each access point in the fire control system;
assigning at least one respective transmission time slot and at least one respective reception time slot to each of the plurality of access points in the fire control system, wherein each of the plurality of access points postpones transmitting messages by entering a low power sleep state until its at least one respective transmission time slot and at least one respective reception time slot within the time-synchronized network occurs and each of the plurality of access points enters the low power sleep state at times outside of the at least one respective transmission time slot and the at least one respective reception time slot of a respective one of the plurality of access points;
determining whether a first access point in the fire control system has a transmission message to transmit during the at least one respective transmission time slot
performing a first attempt to transmit the transmission message from the first access point to the respective primary parent device;
when the first access point fails to receive a first acknowledgement message from the respective primary parent device within a predetermined period of time in response to the first attempt, transmitting the transmission message from the first access point to the respective secondary parent device; and
determining whether the first access point received a second acknowledgement message from the respective secondary parent device before returning to the low power sleep state,
wherein the second acknowledgement message indicates that the respective secondary parent device successfully received the transmission message.

6. The method of claim 5 further comprising the first access point exiting the low power sleep state when the at least one respective transmission time slot or the at least one respective reception time slot occurs.

7. The method of claim 5 wherein transmitting the transmission message from the first access point to the respective primary parent device and transmitting the transmission message from the first access point to the respective secondary parent device includes transmitting alarm or status information regarding the first access point.

8. The method of claim 5 further comprising, after the first access point receives the first acknowledgement message from the respective primary parent device, the first access point entering the low power sleep state.

9. The method of claim 5 further comprising, after the first access point receives the second acknowledgement message from the respective secondary parent device, the first access point entering the low power sleep state.

10. An access point of a time-synchronized network comprising:
a transceiver;
control circuitry;
at least one programmable processor; and
executable control software stored on a non-transitory computer readable medium for:
identifying a primary parent device during start-up of the access point;
identifying a secondary parent device during start-up of the access point;
assigning at least one transmission time slot and at least one reception time slot to the access point, wherein the at least one programmable processor postpones transmitting messages by entering a low power sleep state until its at least one respective transmission time slot and at least one respective reception time slot within the time-synchronized network occurs and wherein the at least one programmable processor enters the low power sleep state at times outside of the at least one respective transmission time slot and the at least one respective reception time slot;
determining whether the access point has a transmission message to transmit during the at least one transmission time slot;
performing a first attempt to transmit the transmission message to the primary parent device;
determining when a first acknowledgement message from the primary parent device is not received within a predetermined period of time in response to the first attempt;
when the first acknowledgement message from the primary parent device is not received within the predetermined period of time in response to the first attempt, transmitting the transmission message to the secondary parent device; and
determining whether the access point received a second acknowledgement message from the secondary parent device before returning to the low power sleep state,
wherein the second acknowledgement message indicates that the secondary parent device successfully received the transmission message.

11. The access point of claim 10 wherein the transceiver includes a radio that is adapted to communicate compliant with an IEEE 802.11 standard.

12. The access

Assignees

• Huseth Steve
• Gonia Patrick
• Berezowski Andrew G
• Kolavennu Soumitri
• Honeywell Int Inc

Inventors

• Huseth Steve
• Gonia Patrick
• Berezowski Andrew G
• Kolavennu Soumitri

Classifications

• H04W92/20

  between access points · CPC title

• H04L45/24

  Multipath · CPC title

• H04W84/18 Primary

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title