Method and system for battery life improvement for low power devices in wireless sensor networks

1. A method at a gateway within a sensor system for communicating with at least one sensor or sensor module, the method comprising:

storing, in a memory of the gateway, a timing profile for communications with the at least one sensor or sensor module;

powering down a processor of the gateway;

waking a radio core of the gateway at a threshold time prior to a transmission time for a sensor beacon signal from the at least one sensor or sensor module;

sampling, with the radio core, a channel for the sensor beacon signal at the radio core while the processor of the gateway is powered down;

if the sensor beacon signal is detected:

waking the processor on the gateway;

exchanging, through the radio core, communication with the at least one sensor or sensor module;

providing, through the radio core, a report to a network server; and

powering down the processor and radio core upon completion of the exchanging communication.

2. The method of claim 1 , wherein the timing profile is sent in a message from the gateway to the at least one sensor or sensor module.

3. The method of claim 1 , wherein the sampling comprises turning on the radio core periodically for a first portion of a sample cycle and turning off the radio core for a remaining portion of the sample cycle.

4. The method of claim 1 , further comprising:

waking the processor and radio core of the processor at a gateway transmit time during the timing profile; and

sending a gateway beacon signal to the at least one sensor or sensor module.

5. The method of claim 4 , wherein a plurality of transmission times for the sensor beacon signal exist between successive scheduled gateway beacon signals.

6. The method of claim 4 , wherein the gateway beacon signal includes a clock signal for the at least one sensor or sensor module to use as a master clock.

7. The method of claim 1 , wherein the timing profile is developed during a learning state between the gateway and the at least one sensor or sensor module.

8. The method of claim 7 , wherein the timing profile differs based on an operational mode of the sensor system.

9. The method of claim 1 , wherein the gateway and the at least one sensor or sensor module are power limited devices.

10. A gateway within a sensor system configured for communicating with at least one sensor or sensor module, the gateway comprising:

a processor; and

a radio core,

wherein the gateway is configured to:

store a timing profile for communications with the at least one sensor or sensor module;

power down the processor of the gateway;

wake the radio core of the gateway at a threshold time prior to a transmission time for a sensor beacon signal from the at least one sensor or sensor module;

sample a channel for the sensor beacon signal at the radio core while the processor of the gateway is powered down;

if the sensor beacon signal is detected:

wake the processor on the gateway;

exchange communication with the at least one sensor or sensor module;

provide a report to a network server; and

power down the processor and radio core upon completion of the exchanging communication.

11. The gateway of claim 10 , wherein the timing profile is sent in a message from the gateway to the at least one sensor or sensor module.

12. The gateway of claim 10 , wherein the gateway is configured to sample by turning on the radio core periodically for a first portion of a sample cycle and turning off the radio core for a remaining portion of the sample cycle.

13. The gateway of claim 10 , wherein the gateway is further configured to:

wake the processor and radio core of the processor at a gateway transmit time during the timing profile; and

send a gateway beacon signal to the at least one sensor or sensor module.

14. The gateway of claim 13 , wherein a plurality of transmission times for the sensor beacon signal exist between successive scheduled gateway beacon signals.

15. The gateway of claim 13 , wherein the gateway beacon signal includes a clock signal for the at least one sensor or sensor module to use as a master clock.

16. The gateway of claim 10 , wherein the timing profile is developed during a learning state between the gateway and the at least one sensor or sensor module.

17. The gateway of claim 16 , wherein the timing profile differs based on an operational mode of the sensor system.

18. The gateway of claim 10 , wherein the gateway and the at least one sensor or sensor module are power limited devices.

19. A non-transitory computer readable medium for storing instruction code, which, when executed by a processor of a gateway within a sensor system configured for communicating with at least one sensor or sensor module cause the gateway to:

store, in a memory of the gateway, a timing profile for communications with the at least one sensor or sensor module;

power down the processor of the gateway;

wake a radio core of the gateway at a threshold time prior to a transmission time for a sensor beacon signal from the at least one sensor or sensor module;

sample, with the radio core, a channel for the sensor beacon signal at the radio core while the processor of the gateway is powered down;

if the sensor beacon signal is detected:

wake the processor on the gateway;

exchange, through the radio core, communication with the at least one sensor or sensor module;

provide, through the radio core, a report to a network server; and

power down the processor and radio core upon completion of the exchanging communication.