Systems and methods for efficiently communicating between low-power devices

• US 10,203,748 B2
• Filed: 06/30/2015
• Issued: 02/12/2019
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google LLC (Alphabet Inc.)
• Inventors: Turon, Martin
• Primary Examiner(s): Banks Harold, Marsha D
• Assistant Examiner(s): Patel, Dharmesh J
• Application Number:
  US14/788,447
• Publication Number:
  US 20170003736A1
• Time in Patent Office: 1,323 Days
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: H04L 12/2816 Controlling appliance services of a home automation network by calling their functionalities 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 H04Q9/00
• CPC Class Codes: H04L 12/4035 in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64
• CPC Class Codes: H04L 2012/2841 Wireless

Abstract

A system includes a first electronic device that activates a first receiver according to a communication schedule that includes a plurality of frames. Each frame is organized according to a grid including a plurality of cells, wherein the cells are associated with a plurality of communication channels and a plurality of time slots. The system also includes a second electronic device that communicates with the first electronic device by transmitting a wake-up packet during a first time slot on a first communication channel. The first time slot and the first communication channel are located at a known position of a respective grid in each frame of the communication schedule. The first electronic device performs an operation based on the wake-up packet after receiving the wake-up packet. The second electronic device also receives a first acknowledgment packet associated with the wake-up packet.

Claims

1. A system configured to communicate according to a communication schedule comprising a plurality of frames, each frame of the plurality of frames being organized according to a grid of cells, each of the cells being associated with one of a plurality of communication channels and one of a plurality of time slots, the system comprising:

a first electronic device configured to activate a receiver according to the communication schedule to receive a wake-up packet that indicates there are data packets to receive from a second electronic device by;

activating the receiver relative to a time slot on a communication channel for a first duration of time;

deactivating the receiver for a second duration of time after the first duration of time expires to reduce power consumption by the first electronic device; and

reactivating the receiver relative to the time slot on the communication channel for a third duration of time after the second duration of time expires, the timing of the activation and the reactivation being disposed about the time slot on the communication channel to account for clock drift of the first electronic device, the second electronic device, or both; and

the second electronic device configured to communicate with the first electronic device by;

transmitting the wake-up packet during the time slot on the communication channel, the time slot and the communication channel being associated with a cell in the communication schedule at a known position in each frame of the plurality of frames of the communication schedule, and the first electronic device being configured to perform an operation based on receiving the wake-up packet; and

in response to the first electronic device receiving the wake-up packet, receiving, from the first electronic device, an acknowledgment packet associated with the wake-up packet.

2. The system of claim 1, wherein the second electronic device is configured to communicate with the first electronic device by transmitting one or more data packets to the first electronic device when the first electronic device is configured to activate the receiver based on the communication schedule.

3. The system of claim 1, wherein the grid of cells indicates at least one time slot and a corresponding communication channel in which a pair of electronic devices are scheduled to communication with each other.

4. The system of claim 1, wherein the first duration of time and the third duration of time comprises approximately 2 mSec, and wherein the second duration of time comprises approximately 1.6 mSec.

5. The system of claim 1, wherein each frame of the plurality of frames of the communication schedule comprises at least one cell that is associated with a pair of devices in a respective grid.

6. The system of claim 5, wherein the at least one cell is in a fixed position in the respective grid of each frame of the plurality of frames.

7. The system of claim 1, wherein the first electronic device and the second electronic device are configured to operate in a low-power mode by operating in a sleep mode for a first period of time and awaking periodically to detect data transmissions.

8. The system of claim 1, wherein the first electronic device is configured to:

receive the wake-up packet after detecting that the wake-up packet is being transmitted during the time slot on the communication channel;

synchronize a clock associated with the first electronic device based on the wake-up packet;

verify that the wake-up packet is received free of any error; and

based upon verification of the wake-up packet, send the acknowledgment packet to the second electronic device.

9. An electronic device configured to communicate with a plurality of electronic devices disposed in a building according to a communication schedule comprising a plurality of frames, each frame of the plurality of frames being organized according to a grid of cells, each of the cells being associated with one of a plurality of communication channels and one of a plurality of time slots, the electronic device comprising a processor configured to:

receive an indication of data to be transmitted to another electronic device of the plurality of electronic devices;

identify a cell in a frame of the grid of the communication schedule in which the electronic device and the other electronic device are scheduled to communicate with each other, the cell being associated with a time slot and a communication channel for the communication; and

transmit a plurality of wake-up packets centered at a time within the time slot to the other electronic device, each of the plurality of wake-up packets being configured to cause the other electronic device to perform an operation based on receiving one of the wake-up packets.

10. The electronic device of claim 9, wherein the processor is configured to transmit one or more data packets associated with the data after receiving an acknowledgment associated with one of the plurality of wake-up packets.

11. The electronic device of claim 9, wherein the data comprises alarm information, one or more sensor measurements, one or more commands, or any combination thereof.

12. The electronic device of claim 9, wherein a number of the plurality of wake-up packets is determined based on an expected amount of time drift between the electronic device and the other electronic device.

13. The electronic device of claim 9, wherein the operation comprises instructions configured to control one or more operations of one or more devices in the building.

14. The electronic device of claim 9, wherein the processor is configured to transmit the plurality of wake-up packets during the time slot, such that the transmission of the plurality of wake-up packets is centered about a double sniff interval of the other electronic device.

15. The electronic device of claim 9, wherein the one of the plurality of wake-up packets comprises time synchronization information associated with a clock of the electronic device.

16. The electronic device of claim 9, wherein the processor is configured to transmit the plurality of wake-up packets when communication between the electronic device and the other electronic device has not occurred for a period of time, when the processor determines that an expected data packet from the other electronic device has not been received, when the processor determines that the other electronic device is not available during a scheduled time according to the communication schedule, or any combination thereof.

17. A method, comprising:

receiving, via a processor of a communication device, a communication schedule comprising a plurality of frames, each frame of the plurality of frames being organized according to a grid of cells, each of the cells being associated with one of a plurality of communication channels and one of a plurality of time slots;

activating, via the processor, a receiver according to the communication schedule and using a double sniff interval, the receiver being configured to receive data packets from another communication device, and the receiver being activated during one of the plurality of time slots and on one of the plurality of communication channels, the double sniff interval being disposed about the one of the plurality of time slots and on the one of the plurality of communication channels;

detecting, via the processor, energy of a wake-up packet when the receiver is activated; and

activating, via the processor, the receiver for a duration of time when the energy is detected, the duration of time corresponding to an amount of time to receive the wake-up packet.

18. The method of claim 17, comprising:

determining, via the processor, time information associated with the other communication device that is included in the wake-up packet; and

adjusting, via the processor, a clock of the communication device based on the time information.

19. The method of claim 17, wherein the communication device comprises a thermostat, a hazard detector, or a portable electronic device, and wherein the wake-up packet comprises instructions to perform an operation configured to adjust a condition in a building.

20. The method of claim 17, wherein using the double sniff interval comprises:

activating the receiver relative to the one of the plurality of time slots on the one of the plurality of communication channels for a first duration of time;

deactivating the receiver for a second duration of time after the first duration of time expires to reduce power consumption by the communication device; and

reactivating the receiver relative to the time slot on the communication channel for a third duration of time after the second duration of time expires.