Method for IOT device to stagger TX and save power
Disclosed are methods and systems for delaying packet transmissions over a wireless communication channel until a more favorable channel condition is detected. A device may measure a channel metric when it receives periodic beacon signals. The device may compare the channel metric against a programmed metric threshold. If the channel metric is less than the metric threshold, the device may delay the transmission of a packet until a later transmission window or transmit opportunity (TXOP) when the channel metric rises above the metric threshold, indicating the presence of a more favorable condition for transmission, or until a preconfigured timeout period elapses before the more favorable condition is found.
1. A method of operating a wireless local area network (WLAN) device, comprising:
receiving, by a WLAN device, a data signal from an access point (AP);
measuring, by the WLAN device, a current channel metric from the data signal;
comparing, by the WLAN device, the current channel metric to a previous channel metric;
determining, by the WLAN device and from the comparison of the current and previous channel metrics, a channel history; and
based on the channel history, programming a threshold for the channel metric, below which transmissions from the WLAN device to the AP are not performed until a timeout is reached.
2. The method of operating a WLAN device of claim 1 , wherein the data signal is a beacon.
3. The method of operating a WLAN device of claim 1 , wherein the data signal is a packet.
4. The method of operating a WLAN device of claim 1 , wherein the current and previous channel metrics include one of a receive channel strength indicator (RSSI), adjacent channel interference (ACI), signal to noise ratio (SNR), noise level, channel condition number of a multiple-in multiple-out (MIMO channel, or an eigen value of a channel matrix.
5. The method of operating a WLAN device of claim 1 , wherein the channel history is determined from the current channel metric and a plurality of previous channel metrics.
6. The method of operating a WLAN device of claim 1 , wherein programming the threshold for the channel metric includes a schedule for the threshold to remain constant.
7. The method of operating a WLAN device of claim 6 , wherein the channel metric is measured periodically to confirm the threshold setting and the schedule.
8. The method of operating a WLAN device of claim 1 , wherein the timeout is less than a lifetime of the MDSU.
9. The method of operating a WLAN device of claim 1 , wherein the programmed threshold may also be programmed as a function of a relative packet length of a modulation coding scheme.
10. A basic service set (BSS) comprising:
an access point (AP); and
a plurality of wireless local area network (WLAN) devices in operative communication with the AP, wherein each of the WLAN devices are configured to:
receive a data signal from an access point (AP),
measure a current channel metric from the data signal,
compare the current channel metric to a previous channel metric,
determine, from the comparison of the current and previous channel metrics, a channel history, and
based on the channel history, program a threshold for the channel metric, below which transmissions from the WLAN device to the AP are not performed until a timeout is reached.
11. The BSS of claim 10 , wherein the data signal is a beacon.
12. The BSS of claim 10 , wherein the data signal is a packet.
13. The BSS of claim 10 , wherein the current and previous channel metrics include one of a receive channel strength indicator (RSSI), adjacent channel interference (ACI), signal to noise ratio (SNR), noise level, channel condition number of a multiple-in multiple-out (MIMO channel, or an eigen value of a channel matrix.
14. The BSS of claim 10 , wherein WLAN devices are sensors configured to communicate environmental information to the AP.
15. The BSS of claim 10 , wherein the WLAN devices are configured to buffer packet transmission to the AP until the channel metric is above the programmed threshold.
16. The BSS of claim 10 , wherein the WLAN devices are configured to transmit a media access control (MAC) service data unit (MSDU) packet during a transmit opportunity (TXOP) when the timeout is reached.
17. The BSS of claim 16 , wherein the timeout is less than a lifetime of the MDSU.
18. The BSS of claim 10 , wherein the programmed threshold may also be programmed as a function of a relative packet length of a modulation coding scheme.