FIELD OF TECHNOLOGY

The present disclosure relates generally to wireless communication systems, and more particularly to wireless communication systems utilizing low power wakeup radios to implement power saving features.

BACKGROUND

Wireless local area networks (WLANs) have evolved rapidly over the past decade, and development of WLAN standards such as the Institute for Electrical and Electronics Engineers (IEEE) 802.11 Standard family has improved single-user peak data throughput. For example, the IEEE 802.11b Standard specifies a single-user peak throughput of 11 megabits per second (Mbps), the IEEE 802.11a and 802.11g Standards specify a single-user peak throughput of 54 Mbps, the IEEE 802.11n Standard specifies a single-user peak throughput of 600 Mbps, and the IEEE 802.11ac Standard specifies a single-user peak throughput in the gigabits per second (Gbps) range. Future standards promise to provide even greater throughput, such as throughputs in the tens of Gbps range.

Some WLANs include low cost wireless devices, such as wireless sensors, that do not require high data rates. To reduce operating costs, it is often useful for such wireless devices to be battery operated or otherwise power constrained. Power saving techniques for reducing power consumption are used with such power-constrained wireless devices. For example, a WLAN network interface of a power-constrained wireless device is put into to a low power state (e.g., a sleep state) for periods of time in order to decrease power consumption of the wireless device. When the wireless device is ready to transmit data to an access point, the WLAN network interface is transitioned to an active state so that the data can be transmitted. After the WLAN network interface transmits the data, the WLAN network interface transitions back to the low power state.

A WLAN network interface of a power-constrained wireless device may “wake up” periodically to listen for transmissions from the access point to determine whether the access point has data to transmit to the wireless device. However, such periodic “wake ups” by the WLAN network interface consume power even when the access point has no data to transmit to the wireless device. Therefore, to further reduce power consumption, some wireless devices employ a low power wake up radio (LP-WUR) that consumes much less power as compared to the WLAN network interface. For example, the LP-WUR does not include any transmitter circuitry and is capable of only receiving very low data rate transmissions. When the access point is ready to transmit data to the wireless device, the access point transmits a wakeup packet addressed to the wireless device. In response to receiving the wakeup packet and determining that the wakeup packet is addressed to the wireless device, the LP-WUR wakes up the WLAN network interface so that the WLAN network interface is ready to receive data from the access point.

SUMMARY

In an embodiment, a method for wireless communications includes: establishing, by an access point, a first communication channel as a primary channel of the access point; transmitting, by the access point, wakeup radio (WUR) beacon frames via a second communication channel that corresponds to a WUR primary channel, wherein the second communication channel is different than the first communication channel; negotiating with a first client station, at the access point, a third communication channel via which the access point is to transmit wakeup frames for the first client station, the third communication channel being different than the second communication channel; generating, at the access point, a first wakeup frame for transmission to the first client station via the third communication channel; generating, at the access point, a wakeup packet to include at least the first wakeup frame; and transmitting, by the access point, the wakeup packet, including transmitting the first wakeup frame to the first client station via the third communication channel.

In another embodiment, a communication device comprises a wireless network interface device associated with an access point. The wireless network interface device includes one or more integrated circuit (IC) devices configured to: establish a first communication channel as a primary channel of the access point; control the wireless network interface device to transmit WUR beacon frames via a second communication channel that corresponds to a WUR primary channel, wherein the second communication channel is different than the first communication channel; negotiate, with a first client station, a third communication channel via which the access point is to transmit wakeup frames for the first client station, the third communication channel being different than the second communication channel; generate a first wakeup frame for transmission to the first client station via the third communication channel; generate a wakeup packet to include at least the first wakeup frame; and control the wireless network interface device to transmit the wakeup packet, including transmitting the first wakeup frame to the first client station via the third communication channel.

In yet another embodiment, a method for wireless communications includes: determining, at a client station, that a first communication channel is a primary channel of an access point; tuning a wakeup radio of the client station to a second communication channel that corresponds to a WUR primary channel of the access point when the access point is to transmit WUR beacon frames, wherein the second communication channel is different than the first communication channel; receiving, at the client station, WUR beacon frames via the second communication channel; negotiating with the access point, at the client station, a third communication channel via which the client station is to receive wakeup frames for the client station, the third communication channel being different than the second communication channel; tuning the wakeup radio of the client station to the third communication channel to receive wakeup frames; receiving, at the client station, a first wakeup frame via the third communication channel; in response to receiving the first wakeup frame, transitioning a wireless network interface of the client station to an active state; and after transitioning the wireless network interface of the client station to the active state, transmitting, by wireless network interface of the client station, a packet via the first communication channel.

In still another embodiment, a communication device comprises: one or more IC devices, and a wireless network interface device associated with a client station. The wireless network interface device is implemented on the one or more IC devices and is configured to: determine that a first communication channel is a primary channel of an access point; and negotiate, with the access point, a second communication channel via which the client station is to receive wakeup frames for the client station. The communication device also comprises a wakeup radio coupled to the wireless network interface device. The wakeup radio is implemented on the one or more IC devices and is configured to: tune to a third communication channel that corresponds to a WUR primary channel of the access point when the access point is to transmit WUR beacon frames, wherein the second communication channel is different than the first communication channel; receive WUR beacon frames via the third communication channel; tune the wakeup radio to the second communication channel to receive wakeup frames; receive a first wakeup frame via the second communication channel; and in response to receiving the first wakeup frame, prompt the wireless network interface to transition to an active state. The wireless network interface device is further configured to, after transitioning to the active state, transmit a packet via the first communication channel.

