Signal strength-based routing of network traffic in a wireless communication system

• US 9,286,787 B2
• Filed: 07/23/2014
• Issued: 03/15/2016
• Est. Priority Date: 05/27/2004
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Kates, Lawrence
• Primary Examiner(s): NWUGO, OJIAKO K
• Application Number:
  US14/338,592
• Publication Number:
  US 20140333434A1
• Time in Patent Office: 601 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 1/3209 Monitoring remote activity, e.g. over telephone lines or network connections
• CPC Class Codes: G08B 1/08 using electric transmission ; transformation of alarm signals to electrical signals from a different medium, e.g. transmission of an electric alarm signal upon detection of an audible alarm signal
• CPC Class Codes: G08B 13/04 by breaking of glass
• 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 21/14 Toxic gas alarms G08B21/16 takes precedence
• CPC Class Codes: G08B 21/182 Level alarms, e.g. alarms responsive to variables exceeding a threshold
• CPC Class Codes: G08B 25/001 Alarm cancelling procedures or alarm forwarding decisions, e.g. based on absence of alarm confirmation
• 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: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
• CPC Class Codes: H04Q 9/02 Automatically-operated arrangements
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A low cost, robust, wireless sensor that provides an extended period of operability without maintenance is described. The wireless sensors are configured to communicate with a base unit or repeater. When the sensor unit detects an anomalous ambient condition (e.g., smoke, fire, water, etc.) the sensor communicates with the base unit and provides data regarding the anomalous condition. The sensor unit receives instructions to change operating parameters and/or control external devices.

Claims

1. A method of routing communication traffic in a wireless sensor system, comprising:

measuring a signal strength of wireless signals received by a first wireless repeater unit from one or more wireless sensor units, one or more wireless base units, and one or more other wireless repeater units;

wirelessly communicating, from the first wireless repeater unit, a first message indicative of the signal strengths measured by the first wireless repeater unit;

updating, at a second wireless repeater unit and based on the first message, a first list comprising wireless sensor units with which the second wireless repeater unit can communicate;

measuring a signal strength of wireless signals received by the second wireless repeater unit from one or more wireless sensor units, one or more wireless base units, and one or more other wireless repeater units;

wirelessly communicating, from the second wireless repeater unit, a second message indicative of the signal strengths measured by the second wireless repeater unit;

updating, at the first wireless repeater unit and based on the second message, a second list comprising wireless sensor units with which the first wireless repeater unit can communicate;

relaying, by the first wireless repeater unit, in accordance with the second list, a first sensor measurement made by a first wireless sensor unit of the one or more wireless sensor units, by transmitting a third message that comprises the first sensor measurement in encrypted form, an address portion, an integrity portion comprising a checksum, and an authentication portion for use in verifying authenticity of the third message, wherein relaying the first sensor measurement comprises;

analyzing, by the first wireless repeater unit, the authentication portion to verify the authenticity of the third message;

ignoring, by the second wireless repeater unit, in accordance with the first list, the first sensor measurement made by the first wireless sensor unit;

relaying, by the second wireless repeater unit, in accordance with the first list, a second sensor measurement made by a second wireless sensor unit of the one or more wireless sensor units, by transmitting a fourth message that comprises the second sensor measurement in encrypted form, an address portion, an integrity portion comprising a checksum, and an authentication portion for use in verifying authenticity of the fourth message, wherein relaying the second sensor measurement comprises;

analyzing, by the second wireless repeater unit, the authentication portion to verify the authenticity of the third message; and

ignoring, by the first wireless repeater unit, in accordance with the second list, the second sensor measurement made by the second wireless sensor unit.

2. The method of routing communication traffic in a wireless sensor system of claim 1, wherein the first and second wireless repeater units respectively communicate the first and second messages only once, without retransmitting the first and second messages.

3. The method of routing communication traffic in a wireless sensor system of claim 1, further comprising causing the first and second wireless repeater units to respectively communicate the first and second messages as part of respective periodic transmissions.

4. The method of routing communication traffic in a wireless sensor system of claim 3, further comprising:

causing the first wireless repeater unit to delay communicating the first message by a first random delay time, and

causing the second wireless repeater unit to delay communicating the second message by a second random delay time.

5. The method of routing communication traffic in a wireless sensor system of claim 1, further comprising causing each of the first and second wireless repeater units to, prior to respectively communicating the first and second messages:

determine whether a radio frequency channel is in use;

transmit the message over the radio frequency channel when it is determined that the radio frequency channel is not in use; and

switch to a different radio frequency channel when it is determined that the radio frequency channel is in use.

6. The method of routing communication traffic in a wireless sensor system of claim 1, further comprising:

causing the first wireless repeater unit to retransmit the first message until the first wireless repeater unit receives a first acknowledgement message, and

causing the second wireless repeater unit to retransmit the second until the second wireless repeater unit receives a second acknowledgement message.

7. The method of routing communication traffic in a wireless sensor system of claim 1, further comprising causing, for each of the first and second wireless repeater units, the wireless repeater unit to include an identifier of the wireless repeater unit in messages communicated by the wireless repeater unit.

8. The method of routing communication traffic in a wireless sensor system of claim 7, wherein the first message includes the identifier of the first wireless repeater unit and the second message includes the identifier of the second wireless repeater unit.

9. A method of routing communication traffic in a wireless communication system, comprising:

measuring a signal strength of wireless signals received by a first wireless repeater unit from one or more wireless sensor units, one or more wireless base units, and/or one or more other wireless repeater units;

wirelessly communicating, from the first wireless repeater unit, a first message indicative of the signal strength measured by the first wireless repeater unit;

measuring a signal strength of wireless signals received by a second wireless repeater unit from one or more wireless sensor units, one or more wireless base units, and/or one or more other wireless repeater units;

wirelessly communicating, from the second wireless repeater unit, a second message indicative of the signal strength measured by the second wireless repeater unit;

selecting routing paths for communication within the wireless communication system based on the first message and the second message;

relaying, by the first wireless repeater unit, based on the selected routing paths, a first sensor measurement made by a first wireless sensor unit of the one or more wireless sensor units, by transmitting a third message that comprises the first sensor measurement in encrypted form, an address portion, an integrity portion comprising a checksum, and an authentication portion for use in verifying authenticity of the first message;

ignoring, by the second wireless repeater unit, in accordance with the first list, the first sensor measurement made by the first wireless sensor unit;

relaying, by the second wireless repeater unit, based on the selected routing paths, a second sensor measurement made by a second wireless sensor unit of the one or more wireless sensor units, by transmitting a fourth message that comprises the second sensor measurement in encrypted form, an address portion, an integrity portion comprising a checksum, and an authentication portion for use in verifying authenticity of the second message; and

ignoring, by the first wireless repeater unit, in accordance with the second list, the second sensor measurement made by the second wireless sensor unit.

10. The method of routing communication traffic in a wireless sensor system of claim 9, wherein the first and second wireless repeater units each have a respective list of sensors and the method further comprises, for each of the first and second wireless repeater units:

causing the wireless repeater unit to forward a fifth message addressed to a sensor on the wireless repeater unit'"'"'s list of sensors; and

causing the wireless repeater unit to ignore a sixth message addressed to a sensor that is not on the wireless repeater unit'"'"'s list of sensors.

11. The method of routing communication traffic in a wireless sensor system of claim 9, wherein the first and second wireless repeater units each have a respective identifier and the method further comprises, for each of the first and second wireless repeater units:

causing the wireless repeater unit to respond to a fifth message having the wireless repeater unit'"'"'s identifier; and

causing the wireless repeater unit to ignore a sixth message that does not have the wireless repeater unit'"'"'s identifier.

12. The method of routing communication traffic in a wireless sensor system of claim 9, further comprising causing the first and second wireless repeater units to respectively communicate the first and second messages using spread spectrum techniques.

13. The method of routing communication traffic in a wireless sensor system of claim 9, further comprising, for each of the first and second wireless repeater units, causing the wireless repeater unit to:

receive a fifth message addressed to a sensor;

extract an address of the sensor from the received message;

determine whether the extracted sensor address is on a list of sensors associated with the wireless repeater unit; and

in response to determining that the extracted sensor address is on the list;

create a new message based on the received message, and

communicate the new message to the sensor having the extracted sensor address.

14. The method of routing communication traffic in a wireless sensor system of claim 9, wherein the first and second wireless repeater units each have a respective list of sensors and the method further comprises, for each of the first and second wireless repeater units:

causing the wireless repeater unit to send a command to one or more sensors on the list of sensors.

15. The method of routing communication traffic in a wireless sensor system of claim 14, wherein the command includes a command to report a battery status.

16. A method of routing communication traffic in a wireless communication system, comprising:

measuring a signal strength of wireless signals received by a first wireless communication device from a first set of one or more other wireless devices within the wireless communication system;

measuring a signal strength of wireless signals received by a second wireless communication device from a second set of one or more other wireless devices within the wireless communication system;

relaying, by the first wireless communication device, in accordance with the selected routing paths, a first sensor measurement made by a first wireless device of the first set of one or more other wireless devices, by transmitting a first message that comprises the first sensor measurement in encrypted form, an address portion, an integrity portion comprising a checksum, and an authentication portion for use in verifying authenticity of the first message;

ignoring, by the second wireless communication device, in accordance with the first list, the first sensor measurement made by the first wireless sensor unit;

relaying, by the second wireless communication device, in accordance with the selected routing paths, a second sensor measurement made by a second wireless device of the second set of one or more wireless devices, by transmitting a second message that comprises the second sensor measurement in encrypted form, an address portion, an integrity portion comprising a checksum, and an authentication portion for use in verifying authenticity of the second message; and

ignoring, by the first wireless communication device, in accordance with the second list, the second sensor measurement made by the second wireless sensor unit.

17. The method of routing communication traffic in a wireless communication system of claim 16, wherein the first wireless communication device comprises a wireless repeater unit and the method further comprises:

receiving, by the wireless repeater unit, a third message from a base unit, wherein the third message includes a command and an identifier;

comparing the identifier of the third message with an identifier of the wireless repeater unit;

executing the command when it is determined that the identifier of the third message matches the identifier of the wireless repeater unit; and

ignoring the command when it is determined that the identifier of the third message does not match the identifier of the wireless repeater unit.

18. The method of routing communication traffic in a wireless communication system of claim 16, wherein selecting the routing paths is based on messages received from the first wireless communication device and the second wireless communication device.

19. The method of routing communication traffic in a wireless communication system of claim 16, further comprising updating, based on the selected routing paths:

a first list comprising wireless sensor units with which the first wireless communication device can communicate, and

a second list comprising wireless sensor units with which the second wireless communication device can communicate.

20. The method of routing communication traffic in a wireless communication system of claim 19, further comprising:

storing the first list at the first wireless communication device; and

storing the second list at the second wireless communication device.