WO2019006030A1

WO2019006030A1 - Methods and arrangements to support compatible low rate for wake-up radio packet transmission

Info

Publication number: WO2019006030A1
Application number: PCT/US2018/039858
Authority: WO
Inventors: Shahrnaz Azizi; Minyoung Park; Thomas Kenney; Po-Kai Huang
Original assignee: Intel Corporation
Priority date: 2017-06-27
Filing date: 2018-06-27
Publication date: 2019-01-03

Abstract

Logic may define two or three or more of different packet formats for a WUR packet. Logic may define a WUR packet format for, e.g., a 1x symbol duration for compatibility with 802.11 main radios. Logic may generate a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols. Logic may apply Manchester coding to the wake-up radio packet transmissions. And logic couple with a physical layer device to generate OOK symbols for a transmission rates of, e.g., 250 kilobits per second and/or 62.5 kilobits per second.

Description

METHODS AND ARRANGEMENTS TO SUPPORT COMPATIBLE LOW RATE FOR WAKE-UP RADIO PACKET TRANSMISSION

TECHNICAL FIELD

Embodiments are in the field of wireless communications. More particularly,

embodiments may support a compatible low transmission rate for wake-up radio packet transmissions for one or more Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards.

BACKGROUND

The increase in interest in network and Internet connectivity and Internet of Things (IoT) drives design and production of new wireless products. Low power consumption is a design factor to facilitate greater usage of wireless devices such as mobile devices and wearable devices. Wireless communication interfaces can consume significant amounts of power so product designs strike a balance between connectivity and power consumption. Thus, a design goal is to lower the power consumption by the wireless communication interfaces to facilitate increased connectivity in terms of distance, speed, and duration of wireless communications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an embodiment of a wireless network to support compatible low rate for wake-up radio packet transmission;

FIG. 2A depicts an embodiment of transmissions between four stations and an AP;

FIG. 2B depicts an embodiment of a transmission between one station and an AP;

FIG. 2C depicts an embodiment of a resource units in a 20 Megahertz (MHz) bandwidth; FIG. 2D depicts an embodiment of an Institute of Electrical and Electronics Engineers

(IEEE) 802.11 orthogonal frequency-division multiple access (OFDMA) modulated signal with a compatible wake-up radio signal at the center resource unit;

FIG. 2E depicts an embodiment of a wake-up radio packet prepended by an IEEE 802.11 physical layer preamble;

FIG. 2F depicts an embodiment of a management frame;

FIG. 2G depicts an embodiment of a wake-up radio capability element;

FIG. 3 depicts an embodiment of an apparatus to support compatible low rate for wake-up radio packet transmission; FIG. 4A depicts an embodiment of a flowchart to generate and transmit a wake-up radio frame; and

FIG. 4B depicts an embodiment of a flowchart to generate and transmit a wake-up radio frame concurrently with another physical layer protocol data unit.

FIG. 4C depicts an embodiment of a flowchart to generate and transmit frames for communications between wireless communication devices; and

FIG. 4D depicts an embodiment of a flowchart to receive and interpret frames for communications between wireless communication devices.

FIGs. 5-6 depict a computer-readable storage medium and a computing platform to support compatible low rate for wake-up radio packet transmission.

DETAILED DESCRIPTION OF EMBODIMENTS

The following is a detailed description of embodiments depicted in the drawings. The detailed description covers all modifications, equivalents, and alternatives falling within the appended claims.

Embodiments may reduce power consumption in wireless communication interfaces by using a low-power wake-up receiver. Such devices are also referred to as wake-up radios (WURs). The low-power wake-up receiver may provide a low-power solution (e.g., -ΙΟΟμ^ν in active state) for, e.g., very low latency Wi-Fi (wireless fidelity) or Bluetooth connectivity of wearable, Internet of Things (IoT), devices and other emerging devices that will be densely deployed and used in the near future.

Some embodiments are particularly directed to improvements for wireless local area network (WLAN), such as a WLAN implementing one or more Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (sometimes collectively referred to as "Wi-Fi", or wireless fidelity). Such standards may include, for instance, the IEEE 802.11-2016, published March 29, 2012, and the IEEE 802.1 lax/D 1.4, published August 2017. The embodiments are not limited to these.

To achieve the target of very low power consumption WUR, embodiments implement waveforms and techniques that allow extremely simple and low cost, low power hardware solutions. This is departure from previous versions of the Wi-Fi standard. One embodiment includes hardware that uses an inexpensive, very low power radio frequency (RF) section with a minimal baseband solution. Some embodiments include a wake-up receiver and no corresponding wake-up transmitter. Other embodiments implement techniques that are more complicated requiring more hardware/cost and power. Different embodiments may provide preferable performance in different deployments or in different scenarios at various price points and power consumption levels.

Some embodiments may transmit the wake-up radio packet signal with an amplitude-shift keying (ASK) modulation such as On-Off Keying (OOK) to achieve a low cost, low power solution. The use of OOK modulation significantly simplifies the hardware involved with the wake-up receiver and increases the sensitivity of the wireless communications interface. Thus, some embodiments may leave the WUR on continuously. Further embodiments may employ cycling of the WUR to further reduce power consumption. For instance, one embodiment may turn on the WUR every second with, e.g., a 50% duty cycle, to reduce power consumption with a slight increase in nominal latency. Another embodiment may turn on the WUR every fourth cycle (25% duty cycle) or turn off the WUR every fourth cycle (75% duty cycle).

Embodiments may facilitate transmission of the WUR packet in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 multi-user, orthogonal frequency-division multiple access (OFDMA) packet format such as an IEEE 802.1 lax OFDMA packet format. In some embodiments, the WUR may transmit a WUR packet without transmitting packets in other sub- bands of the channel. In several embodiments, the WUR may only transmit WUR packets at the slower transmission rates, such as 62.5 kilobits per second (kbps), within a multi-user, OFDMA packet. An example is a physical layer (PHY) device that generates signals to transmit the wake- up radio packet at the center of the band in a multi-user OFDMA transmission that multiplexes IEEE 802.11 transmissions in frequency within the same multi-user OFDMA packet. In other words, the PHY generates signals to transmit multiple different packets on different resource units or frequency sub-bands within the channel simultaneously. In other embodiments, the PHY device may generate signals to transmit the WUR packet at a sub-band that is not at the center of the band of the communication channel.

One embodiment may have only one data rate for transmission of WUR packet to meet the requirements of a WUR with very simple reduced hardware complexity with low cost. Other embodiments may enable two or more data rates for WUR packet transmissions. For instance, embodiments may enable two or more data rates such as (1) a low data rate, e.g., 62.5 kilobits per second (kbps), to meet the IEEE 802.1 lb/1 lax-extended range mode link budget and range and (2) a higher data rate, such as 250 kbps to have shorter packet transmission times, to match (exceed) the link budget of repetition rates in previous Wi-Fi standards. Some embodiments may comprise two different packet/preamble formats for WUR packets for use as a signaling method for the data transmission rate of the WUR packet.

Many embodiments may transmit a wake-up preamble of the WUR packet to synchronize with a WUR of another device. In some embodiments, the wake-up preamble may also include a rate field or a signal field that includes a transmission rate for a medium access control (MAC) layer packet that follows the wake-up preamble. In other embodiments, transmitter uses different preamble sequences to signal the rate. Other embodiments may only be capable of receiving the WUR packet at one rate and, in such embodiments, the WUR packet may not include a rate field or signal field with a transmission rate.

In several embodiments, the communications devices comprising WURs may negotiate a rate of transmission for the MAC data or payload portions of the WUR packets. In other embodiments, the communications devices may negotiate transmission rates for the preamble of the WUR packets also. Embodiments may also negotiate a sub-band or tone within which to transmit a WUR packet. In other embodiments, the WUR may always transmit a WUR packet on the same sub-band of the channel.

Embodiments may implement different transmission rates that are compatible with inclusion in a multi-user, transmission. The embodiments may implement compatible rates with a standard such as such as IEEE 802.11-2016, 802.1 lax, 802.11η, 802.11a, 802.11g, or 802.11ac by transmitting one OOK symbol at the same rate as, e.g., one OFDM symbol. Some embodiments may transmit one OOK symbol or one chip at the same rate as half of an OFDM symbol. For example, the high efficiency (HE) physical layer (PHY) of some embodiments may support, e.g., 0.5x symbol duration, lx symbol duration, 2x symbol duration, and 4x symbol duration. In such embodiments, the PHY may transmit the WUR packet at 0.5x symbol duration, lx symbol duration, 2x symbol duration, or 4x symbol duration. Assuming that the lx symbol duration is 3.2 microseconds and the cyclic prefix (or guard interval) is nominally 0.8 microseconds, one OFDM symbol may transmit in 4.0 microseconds. If the coding rate is one fourth, such as by the application of Manchester coding, the transmission rate is one symbol over the four microseconds times the one fourth coding rate or (1/(4 usecs*4)), which equals about 62.5 kbps, where usees is microseconds.

Several embodiments support different cyclic prefixes. The HE PHY of IEEE 802.11 devices may, for instance, support three cyclic prefixes or guard intervals including 0.8 microseconds, 1.6 microseconds, and 3.2 microseconds. The HE PHY of IEEE 802.11 devices may support transmission rates based on the transmission time or symbol duration for an OFDM symbol plus the cyclic prefix. To illustrate, one embodiment may transmit a compatible WUR packet at 0.5x symbol duration, such as with two OOK symbol transmissions at half of the 3.2 microseconds per symbol plus half of a nominal cyclic prefix of 0.8 microseconds per OOK symbol, which is 4 microseconds total per two OOK symbols, or 2 microseconds per chip (or bit or OOK symbol). If the PHY applies Manchester coding with two symbols per bit of data, then the OOK transmission may be 250 kbps. In other words, each OOK symbol transmits at a rate of (0.5)x(3.2) plus (0.5)x0.8, which equals 2 microseconds.

In discussions about the rate of transmission of an OFDM symbol, the legacy transmission rate for an OFDM symbol is lx symbol duration that has a transmission rate of approximately 4 microseconds per OFDM symbol in accordance with the assumptions above. A new symbol duration described herein is a 4x symbol duration that has a transmission rate of approximately 16 microseconds per OFDM symbol in accordance with the assumptions above. Thus, 62.5 kbps is achievable by transmission of one OOK symbol for every OFDM symbol with a 4x symbol duration or by transmission of four OOK symbols for every OFDM symbol with a lx symbol duration. Furthermore, 250 kbps is achievable by transmission of two OOK symbols for every OFDM symbol with a lx symbol duration by transmission of each OOK symbol during half of a symbol duration.

In many embodiments, the PHY transmits the OOK symbol for a logical one by transmitting the signal for 2 microseconds and not transmitting the signal for 2 microseconds. Similarly, the PHY transmits the OOK symbol for a logical zero by not transmitting the signal for 2 microseconds and transmitting the signal for 2 microseconds or vice versa; meaning, a logical zero by transmitting the signal for 2 microseconds and not transmitting the signal for 2 microseconds, and a logical one by not transmitting the signal for 2 microseconds and transmitting the signal for 2 microseconds.

After transmission of the wake-up radio packet, the WUR circuitry of the PHY of the receiving device may detect the preamble, decode the rate of transmission (if capable of multiple rates), and decode the receiver address. In many embodiments, the rate of the transmission of the preamble is constant regardless of the rate of transmission negotiated for the WUR packet but the PHY transmits the receiver address at the negotiated transmission rate. In other embodiments, the PHY transmits the receiver address at the same rate as the preamble.

Once the WUR circuitry decodes the receiver address, the MAC layer circuitry may determine if the receiver address is addressed to the WUR circuitry. The receiver address may be a MAC address, a WUR address, an association identifier (AID), a broadcast address that identifies a group of receiving devices, or other address. The WUR packet may include a full address, a partial address, or a compressed address (such as a hash of the full or partial address).

The WUR of each communications device may have a unique address. In some embodiments, the address of the WUR differs from the address assigned to main radio of the communications device, such as the MAC address or AID of an IEEE 802.11 main radio. A main radio of a communications device is also referred to as a primary connectivity radio (PCR) and includes a radio that typically has more communication capabilities than a WUR. In other embodiments, the addresses of the PCR and the WUR is the same.

One challenge with multi-user transmission of a WUR packet along with IEEE 802.11 packets, is blocking the adjacent interference to WUR, which may be an inexpensive and low power consuming device. Also, the interference from WUR to the IEEE 802.11 receiver should not cause any degradation in 802.11 performance.

Embodiments may leave adjacent resource units (RUs) blank, or without a data signal to reduce the interference from 802.11 to the WUR. Note that using 802.11 OFDMA numerology with 4x symbol duration will generate lower data rate transmission for a WUR packet. As a result, many embodiments may also comprise an embedded encoder to avoid reducing the data rate to l/4th of lx symbol duration. Some embodiments may populate 802.11 OFDMA subcarriers of 4x symbol duration to generate a WUR packet. By doing so, due to orthogonality of subcarriers, the WUR packet may not cause any interference to 802.11 transmissions.

Embodiments may increase SR of Wi-Fi communications with multiple different bandwidths at different frequency bands. Many embodiments focus on bands between 1 Gigahertz (GHz) and 6 GHz. Some embodiments focus on bandwidths such as 20 Megahertz (MHz), 40 MHz, 80 MHz, 160 MHz, and 80+80 MHz, while other embodiments focus on other bandwidths in the same or other frequency bands. However, the embodiments are not limited to the bandwidths and frequency bands described herein.

Various embodiments may be designed to address different technical problems associated with generating and transmitting a wake-up radio packet that does not significantly impact wireless communications traffic; generating and transmitting a wake-up radio packet that does not cause significant interference to other, concurrent wireless communications; generating and transmitting communications traffic concurrently with communication of a wake-up radio packet; generating and transmitting communications traffic that does not cause significant interference to concurrent communication of a wake-up radio packet; providing low power consumption options for a wake- up radio; providing low cost options for a wake-up radio; providing low-power and low cost options for a wake-up radio; reducing power consumption by a primary connectivity radio; providing wake-up radio solutions at multiple price points with various levels of power consumption; and/or the like.

Different technical problems such as those discussed above may be addressed by one or more different embodiments. Embodiments may address one or more of these problems associated with generation and transmission of a wake-up radio packet. For instance, some embodiments that address problems associated with generation and transmission of a wake-up radio packet may do so by one or more different technical means, such as, generating, by medium access control (MAC) logic circuitry, a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake- up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; communicating the wake-up radio packet to a physical layer device coupled with the MAC logic circuitry, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel; transmitting the wake-up packet by communicating symbols from the physical layer device to a radio coupled with the physical layer device, and communicating radio frequency signals from the radio to one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal; wherein the wake-up radio packet comprises a resource unit of a multi-user, orthogonal frequency-division multiple access (OFDMA) modulated signal; applying Manchester coding to the wake-up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols; transmitting, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lx symbol duration for the wake-up radio signal; wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence; wherein the rate of transmission of one OOK symbol of the wake-up radio packet is equal to the rate of transmission of one 4x OFDM symbol, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second; wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol, wherein the rate of transmission of one OOK symbol is 250 kilobits per second; and/or the like.

Embodiments may facilitate wireless communications in accordance with multiple standards. Some embodiments may comprise low power wireless communications like Bluetooth®, cellular communications, and messaging systems. Furthermore, some wireless embodiments may incorporate a single antenna while other embodiments may employ multiple antennas or antenna elements.

While some of the specific embodiments described below will reference the embodiments with specific configurations, those of skill in the art will realize that embodiments of the present disclosure may advantageously be implemented with other configurations with similar issues or problems.

Turning now to FIG. 1, there is shown an embodiment of a system 1000 to transmit or receive a WUR packet as well as to generate, transmit, receive, decode, and interpret simultaneous transmissions between an access point (AP) and multiple stations (STAs) associated with the AP. The plurality of communications devices comprises STAs 1010 and 1030, and STAs 1090, 1092, 1094, 1096, and 1098. The STA 1010 may be wired and wirelessly connected to each of the STAs 1030, 1090, 1092, 1094, 1096, and 1098 and may comprise an AP.

Each STA 1030, 1090, 1092, 1094, 1096, and 1098 may associate with the STA 1010. For instance, STA 1030 may transmit an association request frame or a reassociation request frame to the STA 1010 via a primary connectivity radio (PCR 1082) of the STA 1030 and the PCR 1080 of the STA 1010. Within the request, the STA 1030 may include information about the capabilities of the STA 1030 including capabilities about a wake-up radio (WUR) circuitry 1050 and/or 1054.

The WUR circuitry 1050 and/or 1054 may provide a capability for the STA 1030 to reduce power consumption while retaining the capability of receiving communications from the STA 1010. The WUR circuitry 1050 (and WUR circuitry 1020) may comprise circuitry and/or a combination of processing circuitry of a baseband processor and code to perform operations or functionality associated with a WUR. The WUR circuitry 1054 (and WUR circuitry 1024) may comprise circuitry such as PHY logic and/or code executed on processing circuitry such as the baseband processor to perform a receiver function to receive wake-up radio packets while the PCR 1082 (and PCR 1080) is in a low power consumption mode such as a sleep mode.

In some embodiments, the WUR circuitry 1024 and WUR circuitry 1054 may include a separate radio and/or a separate antenna (or antenna array) from the PCRs. In other embodiments, the WUR circuitry 1024 may couple with the radio 1026 and the antenna array 1028 of the PCR 1080 for receiving and/or transmitting WUR packets. In still other embodiments, the STA 1010 and/or other STAs may include wake-up receivers but may not include a corresponding wake-up transmitter. For instance, the STA 1010 may comprise AP functionality and may include a wake- up transmitter to transmit wake-up packets. The rest of the STAs that do not include AP functionality may include wake-up receivers to receive a WUR packet and may or may not include wake-up transmitters.

During association, the STA 1010 may select a WUR capability based on the WUR capabilities that the STA 1030 communicates to the STA 1010. In some embodiments, the STA 1030 may transmit a WUR capability element such as an information element in the association frame or reassociation frame to the STA 1010. After associating with the STA 1010, each station 1030, 1090, 1092, 1094, 1096, and 1098 may receive a channel sounding packet for beamforming at their respective PCRs. In many embodiments, the channel sounding packet may comprise a physical layer (PHY) null data packet (NDP). For instance, the channel sounding packet may include a very high throughput (VHT) NDP or a high efficiency (HE) NDP. In some embodiments, the MAC logic circuitry 1018 of the STA 1010 may control the timing of transmission of the channel sounding packet.

The beamforming may facilitate directional transmissions from the STA 1010 to the other STAs 1030, 1090, 1092, 1094, 1096, and 1098. In some embodiments, the receivers of the STAs 1030, 1090, 1092, 1094, 1096, and 1098 may be capable of directional receipt of the transmissions from the STA 1010. Furthermore, one or more of the STAs 1030, 1090, 1092, 1094, 1096, and 1098 may also transmit sounding packets to the STA 1010 to beamform transmissions to the STA 1010 and may perform such beamforming.

In several embodiments, the PCR 1080 of the STA 1010 may negotiate a transmission rate for transmission of WUR packets with the PCRs of other STAs such as STA 1030. The negotiation may involve selection by the STA 1010 of a transmission rate from one or more transmission rates in the capabilities of received from the STA 1030. In some embodiments, the STA 1030 may only include one transmission rate such as 62.5 kbps. In other embodiments, the STA 1030 may include more than one transmission rates such as 62.5 kbps and 250 kbps.

In further embodiments, the PCR 1080 of the STA 1010 may negotiate a transmission rate for transmission of WUR packets with the PCR 1082 of the STA 1030 by selection of the highest transmission rate at which, the WUR circuitry 1054 is capable of receiving a WUR packet. In some embodiments, the PCR 1082 of the STA 1030 may indicate a preference for or request a lower transmission rate or the lowest transmission rate at which the WUR circuitry 1082 is capable of receiving the WUR packet.

In several embodiments, the STA 1010 may also negotiate with the STA 1030 to determine a duration of OOK symbols of the WUR packet. For instance, the STA 1010 may be capable of 0.5x OFDM symbol duration, lx OFDM symbol duration, 2x OFDM symbol duration, 4x OFDM symbol duration, and/or the like. The STA 1030 may be capable of lx OFDM symbol duration and/or 0.5x OFDM symbol duration so the STA 1010 may select from the symbol duration capabilities of the STA 1030 based on one or more criteria such as an indication of a type of STA associated with the STA 1030, an indication of a power mode of the STA 1030, an indication of a type of power source associated with the STA 1030, and/or the like. These criteria may be determined by the STA 1010 directly from capabilities communicated from the STA 1030 or indirectly through other information received from the STA 1030. In several embodiments, the STA 1010 may also negotiate a schedule and/or duty cycle for one or more of the STAs 1030, 1090, 1092, 1094, 1096, and 1098. The schedule may include times, while the PCR 1082 is in a low power mode, during which the STA 1030 should wake the WUR circuitry 1054 to receive WUR packets such as a non-periodic or an adaptive schedule that can facilitate longer down times if no traffic is expected. The duty cycle may indicate a periodic timing during which the WUR circuitry 1054 may be awake and ready to receive WUR packets. In many embodiments, the STA 1010 may also negotiate a duty cycle and/or schedule for the PCRs of the STAs such as the PCR 1082 of STA 1030.

After negotiating parameters related to the WUR circuitry 1054, the STA 1030 may place the PCR 1082 into a sleep mode during which the PCR 1082 is unable to receive packets. The STA 1010 may determine to wake the PCR 1082 of STA 1030 to transmit an 802.11 packet and may, in response to the determination, transmit a WUR packet.

The PCR 1080 of the STA 1010 may be capable of transmitting the WUR packet within a sub-band of a channel within which the STA 1010 transmits 802.11 packets such as 802.11 packets. In some embodiments, the WUR circuitry 1020 of the MAC logic circuitry 1018 may generate the WUR packet, transmit/receive (TX/RX) circuitry 1025 of the PCR 1080 may generate symbols to transmit the WUR packet, the radio 1026 may generate radio frequency signals based on the symbols, and the antenna array 1028 may transmit the radio frequency signals that represent the WUR packet to the STA 1030.

In some embodiments, the antenna array 1058 of STA 1030 may receive the radio signals that represent the WUR packet, the radio 1056 may convert the signals to symbols, and the WUR circuitry 1054 may convert the symbols into a WUR packet. In response to receipt of the WUR packet, the WUR circuitry 1054 may determine if the WUR packet is addressed to the STA 1030 and, in response to determining that the WUR packet is addressed to the STA 1030, the WUR circuitry 1054 may wake the PCR 1082.

The STAs 1010 and 1030 comprise processor(s) 1001 and 1031, and memory 1011, and 1041, respectively. The processor(s) 1001 and 1031 may comprise any data processing device such as a microprocessor, a microcontroller, a state machine, and/or the like, and may execute instructions or code in the memory 1011 and 1041. The memory 1011 and 1041 may comprise a storage medium such as Dynamic Random- Access Memory (DRAM), read only memory (ROM), buffers, registers, cache, flash memory, hard disk drives, solid-state drives, or the like. The memory 1011 and 1041 may store the frames, frame structures, frame headers, or the like, and may also comprise WUR logic as code for execution by processing circuitry of a processor such as the processors 1011 and 1031 and/or the baseband processors of the MAC logic circuitry 1018 and 1048. The STAs 1010 and 1030 comprise wireless network interfaces 1022 and 1052, respectively. The wireless network interfaces 1022 and 1052 may support one or more types and formats of wireless communications such as 802.11 communications, cellular data communications, and/or the like. The wireless network interfaces 1022 and 1052 may comprise one or more main radios such as the PCR 1080 and PCR 1082, respectively, and one or more WURs such as the WUR circuitry 1020 and 1024, and 1050 and 1054.

Each PCR 1080 and 1082 may include baseband circuitry such as MAC logic circuitry 1018 and 1048, respectively, RX/TX circuitry 1025 and 1055, respectively, radios 1026 and 1056, respectively, and antenna arrays 1028 and 1058, respectively. The MAC logic circuitry 1018 and 1048 may comprise one or more circuits to implement MAC layer functionality and management service interfaces through which MAC layer management functions may be invoked. The MAC logic circuitry 1018 and 1048 may comprise one or more processors to execute MAC layer code stored in the memory 1011 and 1041, respectively. In other embodiments, the MAC logic circuitry 1018 and 1048 may comprise interface circuitry to execute code on the one or more processors 1001 and 1031, respectively.

The MAC logic circuitry 1018 and 1048 may communicate with the physical layer (PHY) logic circuitry of wireless network interfaces 1022 and 1052, respectively, to generate signals to transmit a PHY frame such as a channel sounding packet or may provide a MAC frame to the PHY logic circuitry to transmit to the STA 1030 and the STA 1010, respectively. The MAC logic circuitry 1018 and 1048 may generate frames such as management, data, control frames, extended frames, and/or the like.

The PHY logic circuitry 1023 and 1053 of wireless network interfaces 1022 and 1052, respectively, may include logic implemented in circuitry may also include logic implemented as code to execute on the baseband processor of the MAC logic circuitry 1018 and 1048, respectively. The PHY logic circuitry 1023 and 1053 may prepare the MAC frame for transmission by, e.g., determining a preamble to prepend to a MAC frame to create a PHY frame. The preamble may include one or more short training field (STF) values, long training field (LTF) values, and signal (SIG) field values. The RX/TX circuitry 1025 and 1055 may be PHY layer devices including a transmitter and a receiver and the transmitter may process the PHY frame for transmission via the radios 1026 and 1056, respectively and the antenna arrays 1028 and 1058, respectively.

After processing the PHY frame, the radios 1026 and 1056, may impress digital data onto subcarriers of RF frequencies for transmission by electromagnetic radiation via elements of an antenna arrays 1028 and 1058, respectively. The antenna arrays 1028 and 1058 may each comprise one or more antennas and/or one or more antenna elements such as antenna elements on an integrated circuit. The RF receiver receives electromagnetic energy, extracts the digital data, and decodes the frame.

FIGs. 2A-2C illustrate embodiments of channels and subchannels, also referred to as sub- bands or resource units, that can facilitate multiple transmissions simultaneously or concurrently along with transmission of a WUR packet. FIG. 2A illustrates an embodiment of transmissions 2010 between four stations and an AP on four different subchannels of a channel via OFDMA. Grouping subcarriers into groups of resource units is referred to as subchannelization. Subchannelization defines subchannels that can be allocated to stations depending on their channel conditions and service requirements. An OFDMA system may also allocate different transmit powers to different subchannels.

In the present embodiment, the OFDMA STA1, OFDMA STA2, OFDMA STA3, and OFDMA STA4 may represent transmissions on a four different subchannels of the channel. As a comparison, FIG. 2B illustrates an embodiment of an OFDM transmission 2015 for the same channel as FIG. 2A. The OFDM transmission 2015 may use the entire channel bandwidth.

FIG. 2C illustrates an embodiment of a 20 Megahertz (MHz) bandwidth 2020 on a channel that illustrates different resource unit (RU) configurations 2022, 2024, 2026, and 2028. In OFDMA, for instance, an OFDM symbol is constructed of subcarriers, the number of which is a function of the physical layer protocol data unit (PPDU) (also referred to as the PHY frame) bandwidth. There are several subcarrier types: 1) Data subcarriers which are used for data transmission; 2) Pilot subcarriers which are utilized for phase information and parameter tracking; and 3) unused subcarriers which are not used for data/pilot transmission. The unused subcarriers are the DC subcarrier, the Guard band subcarriers at the band edges, and the Null subcarriers.

The RU configuration 2022 illustrates an embodiment of nine RUs that each include 26 subcarriers for data transmission including the two sets of 13 subcarriers on either side of the DC. The RU configuration 2024 illustrates the same bandwidth divided into 5 RUs including four RUs with 52 subcarriers and one RU with 26 subcarriers about the DC for data transmission. The RU configuration 2026 illustrates the same bandwidth divided into 3 RUs including two RUs with 106 subcarriers and one RU with 26 subcarriers about the DC for data transmission. And the RU configuration 2028 illustrates the same bandwidth divided into 2 RUs including two RUs with 242 subcarriers about the DC for data transmission. Embodiments may be capable of additional or alternative bandwidths such as such as 40 MHz, 80 MHz, 160 MHz and 80+80MHz.

FIG. 2D depicts an embodiment 2100 of an IEEE 802.11 orthogonal frequency-division multiple access (OFDMA) modulated signal with a compatible wake-up radio (WUR) signal at the center resource unit of a channel. In this embodiment, the channel bandwidth is 20 megahertz (MHz) and the WUR packet transmission is on a 4 MHz sub-band of the 20 MHz channel. A physical layer device, such as the PCR 1080 shown in FIG. 1, generates a legacy preamble 2110 and a high-efficiency preamble 2115. The legacy preamble 2110 may include a network allocation vector (NAV) to inform 802.11 legacy devices that the channel is busy for a duration of time. The high-efficiency preamble 2115 may include training symbols such as short training symbols, long training symbols, one or more signal fields, possibly other data, and the like. A physical PHY layer device generates signals to transmit the WUR packet 2120 at the center of the band in a multi-user OFDMA transmission. The physical PHY layer device multiplexes IEEE 802.11 transmissions in frequency within the same multi-user OFDMA packet. In other words, the PHY device generates signals to transmit multiple different packets on different resource units (RUs) or frequency sub-bands within the channel simultaneously via antenna elements of an antenna array such as the antenna array 1028 in FIG. 1. Furthermore, the PHY device may beamform the transmissions on each RU independently with different subsets of the antenna elements. In other embodiments, the PHY device may generate signals to transmit the WUR packet 2120 at a sub-band that is not at the center of the band of the communication channel.

In some embodiments, the PHY device may have only one data rate for transmission of

WUR packet 2120 to meet the requirements of a WUR with very simple reduced hardware complexity with low cost. In some embodiments, the PHY device may enable two or more data rates for WUR packet transmissions. For instance, embodiments may enable two or more data rates such as (1) a low data rate, such as 62.5 kbps to meet, e.g., the IEEE 802.1 lb/1 lax-extended range mode link budget and range and (2) a higher data rate, such as 250 kbps to have shorter packet transmission times, to match (exceed) the link budget of repetition rates in previous Wi-Fi standards. Some embodiments may comprise two different packet/preamble formats for WUR packets to be used as a signaling method for the data rate of the WUR packet 2120.

The RU 1, RU 2, RU 8, and RU 9 may each include a remaining portion of a physical layer data unit (PPDU) that follows the legacy and HE preambles. The RU 3 and RU 7 may be the RUs that are immediately adjacent to the WUR packet 2120. In some embodiments, these RUs include no signals or include signals that minimize interference between the WUR transmission and the transmissions on RU 2 and RU 8.

In the present embodiment, each RU includes a 2 MHz bandwidth with 26 subcarriers and the WUR packet resides on RUs 4, 5, and 6. The WUR packet transmits on a 4 MHz bandwidth within these three RUs. In other embodiments, the bandwidths may vary such as the different RUs 2022 through 2028 shown in FIG. 2C for a 20 MHz bandwidth. In still other embodiments, the channel for transmission may be greater than 20 MHz such as 40 MHz, 60 MHz, 80 MHz, 160 MHz, and the like. In further embodiments, the WUR packet may transmit on two RUs that have 4 MHz and 52 subcarriers. The FIG. 2E illustrates an embodiment of a WUR packet structure 2200. FIG. 2E illustrates an 802.11 preamble 2210 that comprises a single STF field 2211, a single LTF field 2212, and a single SIG field 2213. These fields represent an IEEE 802.11 preamble 2210 such as an IEEE 802.11 ah preamble. For IEEE 802.1 lax, the preamble may include a legacy IEEE 802.11 preamble 2110 followed by a high efficiency (HE) preamble 2115. Other embodiments of the 802.11 preamble may include one or more preambles for one or more 802.11 standards.

After the 802.11 preamble 2210, which may be transmitted across the entire bandwidth of the channel such as the entire 20 MHz channel as shown in FIG. 2D, the WUR packet structure 2200 comprises a wake-up preamble 2215, a MAC header 2220, a payload 2225, and a frame check sequence (FCS) field 2230. The wake-up preamble 2215 may include a series of two repetitions of a 16-bit sequence 2216 and 2217. In several embodiments, the series of two repetitions of a 16-bit sequence 2216 and 2217comprise two repetitions of the same sequence of bits that transmit at a constant rate regardless of the negotiated rate for transmission of the WUR packet. Some embodiments may include more or less repetitions of the 16-bit sequence. Some embodiments may include more or less bits in the sequence and some embodiments may include more than one different sequences of bits in the wake-up preamble.

Some embodiments include a rate field in the wake-up preamble and other embodiments include a rate field that immediately follows the second 16-bit sequence in the wake-up preamble. The receiver address may follow the rate field, in some embodiments, to facilitate transmission of the receiver address at a different rate than the rate of transmission of the wake-up preamble.

The MAC header 2220 may include a receiver ID 2221 that is or indicates the receiver address. The receiver ID may comprise a partial MAC address for an intended receiving station. In other embodiments, the receiver ID may comprise a full MAC address for the intended receiving station. In some embodiments, the MAC header may include more fields.

The payload 2225, in the present embodiment, includes an action identifier (ID) 2226 and an action payload 2227. The action ID 2226 may identify the structure of the action payload 2227 and the action payload 2227 may include an instruction to wake a main radio such as an IEEE 802.1 lax radio either immediately or after a period of time. In some embodiments, the period of time may identify a target time for the primary connectivity radio to be ready to receive a packet. In other embodiments, the WUR packet does not include a payload.

After the payload 2225, or MAC header 2220 if no payload 2225, the WUR packet 2200 includes a frame check sequence (FCS) 2230 to verify the packet. In other embodiments, the WUR packet 2200 may include an encryption hash in addition to or in lieu of the FCS 2230.

The WUR circuitry may implement two or more different packet and/or preamble formats for WUR packets such as one for a higher data rate, e.g., of 250 kbps using 0.5x symbol duration as in, e.g., 802.11n/llac and one for a lower data rate, e.g., of 62.5 kbps using lx symbol duration of, e.g., 802.11ax. In some embodiments, the WUR may also implement different packet and/or preamble formats for multiple lower data rates such as 62.5 kbps or 31.25 kbps using 4xSym duration. In some embodiments, one or more of or all the packet and/or preamble formats also support multi-user transmissions comprising a WUR packet with 802.11 packets on different sub- bands of the channel for 802.11 devices.

Although this appears to add a bit more complexity to the design, it is argued that there is no increase in the AP nor the WUR. In the WUR circuitry, for instance, the receiver may use a simple correlator as a detector, so changing the symbol time may only increase the integration time of the receiver.

One embodiment defines the following two packet formats for a WUR packet 2200:

(1) Based on 802.11 lx symbol duration. This means that each OOK symbol may be 3.2 microseconds (usecs)+ a cyclic prefix (CP) which is nominally 0.8 usees for the total of 4 usees (normal GI). As noted above, Manchester coding may also be added such as a one fourth coding rate. This may mean that transmission of an information bit 1 and bit 0 may be done by transmitting tuples of four OOK symbols (OFDM symbols) (0,1,0,1) for a logical one and (1,0,1,0) for a logical zero or vice versa and hence the duration of transmitting one information bit may be 16 usees, which gives a 62.5 kbps rate.

(2) Based on 802.11 0.5x symbol duration. This means that each OOK symbol may be half of 3.2 usees + a cyclic prefix (CP) which is nominally 0.8 usee for the total of 2 usees (normal GI).

As noted above, Manchester coding may also be added such as a one-half coding rate. This may mean that transmission of an information bit 1 and bit 0 may be done by transmitting tuples of two OOK symbols (OFDM symbols) (0,1) for a logical one and (1,0) for a logical zero or vice versa (0,1) for a logical zero and (1,0) for a logical one and hence the duration of transmitting one information bit may be 4 usees, which gives a 250 kbps rate.

An advantage of such embodiments is that spectrum utilization can be improved when low data rate is used because an access point (AP) can transmit a WUR packet 2200 along with 802.11 packets simultaneously using OFDMA.

Transmission at the AP may involve utilization of one or more of transmission rates of the WUR packet 2200. Reception at WUR devices may involve a WUR device that is unaware whether the packet is a multi-user (e.g., multiplexed with 802.1 lax) or a single user transmission. The WUR receiver may search for preamble 2215 sequences and/or a signal field (also referred to as a rate field) to detect the start of the WUR packet 2200 and to identify its transmission rate. The rate is either detected through the use of different preamble sequences (which could be different for 4x symbol duration vs. lx symbol duration or 4x symbol duration) and/or through decoding of the signal field, or rate field, that carries the rate information. In some embodiments, each of different preamble sequences can represent a different rate and, thus, no additional rate information is needed to signal a negotiated rate for transmission of the wake-up radio packet. In further embodiments, one or more of the different preamble sequences may represent different rates so more than one of the preamble sequences may represent the same rate of transmission.

Once the rate of transmission is decoded, the WUR receiver may process each OOK symbol assuming either a high rate of 2 usees or low rate of 16 usees. In many embodiments, this could may be extended to other rates.

FIG. 2F depicts an embodiment of a management frame 2400 for transmission and receipt by PCRs of STAs such as the PCRs 1080 and 1082 of the STAs 1010 and 1030, respectively, as shown in FIG. 1. The WUR capable STAs 1030 and 1010 may exchange the capability for supported rate and format and negotiate the supported rates (for embodiments in which the support of one or more rate is optional) and/or tone (or sub-band or RU(s)) location within the channel via PCRs 1080 and 1082 when setting up the WUR operation. For instance, the STA 1010 may advertise capabilities in a management frame 2400 such as a beacon frame, an association response frame, or a reassociation response frame to indicate support of transmitting 0.5x symbol duration WUR signal. The STA 1030 may indicate support of receiving 0.5x symbol duration WUR signal in a management frame 2400 such as an association request frame or reassociation request frame.

The above two capability indications can be included WUR capability element such as the WUR capability element 2500 illustrated in FIG. 2G. In some embodiments, the WUR capability element 2500 illustrated in FIG. 2G may be included in a frame body 2434 of a frame such as the management frame 2400 illustrated in FIG. 2F. In such embodiments, the WUR capability element 2500 may be in another field of the management frame 2400 such as in the frame control field 2410.

In several embodiments, the STA 1010 and the STA 1030 can negotiate the tone location of the WUR packet such as an RU about the center of the channel as shown in FIG. 2D, a different RU within the channel shown in FIG. 2D, or at an RU of a different bandwidth in the channel or an RU in a channel with a different bandwidth.

Embodiments may define two or three or more different packet structures for one or more high rate and one or more low rate WUR packets. To enable better spectrum efficiency, some embodiments include low data rate transmissions within in, e.g., 802.1 lax multi-user OFDMA packets, to allow concurrent transmission of 802.11 packets with a WUR packet. The multi-user transmission may occupy more bandwidth than 4 MHz, which in turn overcomes the regulatory specified Tx-PSD limit (Power Spectral Density limit), and hence the AP can transmit at higher Tx-power (transmission power). Many embodiments may provide a wireless connectivity solution for mobile/wearable devices that can minimize power consumption.

The management frame 2400 is one embodiment of a frame that can transmit the WUR capability element 2500 illustrated in FIG. 2G to negotiate one or more WUR packet parameters such as the symbol duration of lx or 0.5x 2510 and/or a transmission rate such as 250 kbps or 62.5 kbps. The choice of fields for communicating information may be application specific. In other embodiments, for example, the management frame 2400 may have more or less fields, different fields, and/or fields with different field lengths.

The management frame 2400 may comprise a MAC header with a frame control field 2410, a duration field 2430, address(es) field(s) 2432, a frame body 2434, and a frame check sequence (FCS) field 2436. The frame control field 2410 may comprise a protocol version field 2412, a type field 2414, a subtype field 2416, and other frame control bits 2418. The protocol version field 2412 may represent the revision of the corresponding standard that the frame represents. The type field 2414 may identify the type of frame 2414 as, e.g., a control frame. The subtype field 2416 may identify the subtype of the frame as, e.g., a particular type of control frame such as an association frame. The other frame control bits 2418 may represent additional fields that may be present in the frame control field such as a more fragments field, a retry field, a power management field, a more data field, or the like.

The duration field 2420 may include a duration of a network allocation vector (NAV) reminder in microseconds. The ADDR(s) field(s) 2432 may include a broadcast address to broadcast to each station associated with the STA 1010 and an address of a specific STA. The ADDR(s) field(s) 2432 may include a full or partial address or a compressed address such as a MAC address of a STA.

FIG. 3 depicts an embodiment of an apparatus to generate, transmit, receive, and interpret or decode PHY frames and MAC frames with a WUR packet to support compatible low rate for wake-up radio packet transmission. The apparatus comprises a transceiver 300 coupled with MAC logic circuitry 301 and PHY logic circuitry 302. The MAC logic circuitry 301 and PHY logic circuitry 302 may comprise code executing on processing circuitry of a baseband processor and/or other processor; circuitry to implement operations of functionality of the MAC or PHY; or a combination of both. The MAC logic circuitry 301 may determine a frame such as a CBF announcement frame and the PHY logic circuitry 302 may determine the physical layer protocol data unit (PPDU) by prepending the frame or multiple frames, also called MAC protocol data units (MPDUs), with a preamble to transmit.

The transceiver 300 comprises a receiver 304 and a transmitter 306. Embodiments have many different combinations of modules to process data because the configurations are deployment specific. FIG. 3 illustrates some of the modules that are common to many embodiments.

The transmitter 306 may comprise one or more of an encoder 308, a stream deparser 364, a frequency segment parser 307, an interleaver 309, a modulator 310, a frequency segment deparser 360, an OFDM 312, an IFFT 315, a GI 345, and a transmitter front end 340. The encoder 308 of transmitter 306 receives and encodes a data stream destined for transmission from the MAC logic circuitry 302 with, e.g., a binary convolutional coding (BCC), a low-density parity check coding (LDPC), and/or the like. After coding, scrambling, puncturing and post-FEC padding, a stream parser 364 may optionally divide the data bit streams at the output of the FEC encoder into groups of bits. The frequency segment parser 307 may receive data stream from encoder 308 or streams from the stream parser 364 and optionally parse each data stream into two or more frequency segments to build a contiguous or non-contiguous bandwidth based upon smaller bandwidth frequency segments. The interleaver 309 may interleave rows and columns of bits to prevent long sequences of adjacent noisy bits from entering a BCC decoder of a receiver.

The modulator 310 may receive the data stream from interleaver 309 and may impress the received data blocks onto a sinusoid of a selected frequency for each stream via, e.g., mapping the data blocks into a corresponding set of discrete amplitudes of the sinusoid, or a set of discrete phases of the sinusoid, or a set of discrete frequency shifts relative to the frequency of the sinusoid. In some embodiments, the output of modulator 309 may optionally be fed into the frequency segment deparser 360 to combine frequency segments in a single, contiguous frequency bandwidth of, e.g., 160 MHz. Other embodiments may continue to process the frequency segments as separate data streams for, e.g. a non-contiguous 80+80 MHz bandwidth transmission.

After the modulator 310, the data stream(s) are fed to an OFDM module 312. The OFDM module 312 may comprise a space-time block coding (STBC) module 311, and a digital beamforming (DBF) module 314. The STBC module 311 may receive constellation points from the modulator 309 corresponding to one or more spatial streams and may spread the spatial streams to a greater number of space-time streams. Further embodiments may omit the STBC.

The OFDM module 312 impresses or maps the modulated data formed as OFDM symbols onto a plurality of orthogonal subcarriers so the OFDM symbols are encoded with the subcarriers or tones. The OFDM symbols may be fed to the DBF module 314. Generally, digital beam forming uses digital signal processing algorithms that operate on the signals received by, and transmitted from, an array of antenna elements. Transmit BF processes the channel state to compute a steering matrix that is applied to the transmitted signal to optimize reception at one or more receivers. This is achieved by combining elements in a phased antenna array in such a way that signals at particular angles experience constructive interference while others experience destructive interference. The Inverse Fast Fourier Transform (IFFT) module 315 may perform an inverse discrete Fourier transform (IDFT) on the OFDM symbols to map on the subcarriers. The guard interval (GI) module 345 may insert guard intervals by prepending to the symbol a circular extension of itself. The GI module 345 may also comprise windowing to optionally smooth the edges of each symbol to increase spectral decay.

The output of the GI module 345 may enter the transmitter front end 340. The transmitter front end 340 may comprise a radio 342 with a power amplifier (PA) 344 to amplify the signal and prepare the signal for transmission via the antenna array 318. In many embodiments, entrance into a spatial reuse mode by a communications device such as a station or AP may reduce the amplification by the PA 344 to reduce channel interference caused by transmissions.

The transceiver 300 may also comprise duplexers 316 connected to antenna array 318. The antenna array 318 radiates the information bearing signals into a time- varying, spatial distribution of electromagnetic energy that can be received by an antenna of a receiver. In several embodiments, the receiver 304 and the transmitter 306 may each comprise its own antenna(s) or antenna array(s).

The transceiver 300 may comprise a receiver 304 for receiving, demodulating, and decoding information bearing communication signals. The receiver 304 may comprise a receiver front-end to detect the signal, detect the start of the packet, remove the carrier frequency, and amplify the subcarriers via a radio 352 with a low noise amplifier (LNA) 354. The receiver 304 may comprise a GI module 355 and a fast Fourier transform (FFT) module 319. The GI module 355 may remove the guard intervals and the windowing and the FFT module 319 may transform the communication signals from the time domain to the frequency domain.

The receiver 304 may also comprise an OFDM module 322, a frequency segment parser 362, a demodulator 324, a deinterleaver 325, a frequency segment deparser 327, a stream deparser 366, and a decoder 326. An equalizer may output the weighted data signals for the OFDM packet to the OFDM module 322. The OFDM 322 extracts signal information as OFDM symbols from the plurality of subcarriers onto which information-bearing communication signals are modulated.

The OFDM module 322 may comprise a DBF module 320, and an STBC module 321. The received signals are fed from the equalizer to the DBF module 320. The DBF module 320 may comprise algorithms to process the received signals as a directional transmission directed toward to the receiver 304. And the STBC module 321 may transform the data streams from the space- time streams to spatial streams.

The output of the STBC module 321 may enter a frequency segment parser 362 if the communication signal is received as a single, contiguous bandwidth signal to parse the signal into, e.g., two or more frequency segments for demodulation and deinterleaving. The demodulator 324 demodulates the spatial streams. Demodulation is the process of extracting data from the spatial streams to produce demodulated spatial streams. The deinterleaver 325 may deinterleave the sequence of bits of information. The frequency segment deparser 327 may optionally deparse frequency segments as received if received as separate frequency segment signals, or may deparse the frequency segments determined by the optional frequency segment parser 362. The decoder 326 decodes the data from the demodulator 324 and transmits the decoded information, the MPDU, to the MAC sublayer logic 302.

The MAC logic circuitry 301 may parse the MPDU based upon a format defined in the communications device for a frame to determine the particular type of frame by determining the type value and the subtype value. The MAC logic circuitry 301 may then interpret the remainder of MPDU.

While the description of FIG. 3 focuses on a single spatial stream system for simplicity, many embodiments are capable of multiple spatial stream transmissions and use parallel data processing paths for multiple spatial streams from the PHY logic circuitry 302 through to transmission. Further embodiments may include the use of multiple encoders to afford implementation flexibility.

FIGs. 4A-B depict embodiments of flowcharts 4000 and 4100 to transmit communications with a frame. Referring to FIG. 4A, the flowchart 400 may begin with a PCR of a communications device, generating an 802.11 preamble for transmission on a channel (element 4010) such as a legacy preamble and high-efficiency preambles shown in FIG. 2D or the 802.11 preamble shown in FIG. 2E.

A MAC layer logic circuitry of the PCR may generate the frame as a wake-up radio (WUR) packet to transmit to other devices of a network, including the wake-up preamble (element 4015) and a frame body. The frame body may include, e.g., a receiver address and a frame body and the MAC layer logic circuitry may pass the frame as an MAC protocol data unit (MPDU) to a PHY logic circuitry of the PCR. The PHY logic circuitry may transform the data into a packet of OFDM symbols that can be transmitted to a STA after transmission of the 802.11 preamble.

The PCR may transmit a wake-up preamble on a sub-band of the channel after transmission of the 802.11 preamble(s) and may transmit the remainder of the WUR packet after transmission of the wake-up preamble as one or more OOK symbols at a rate equal to the transmission rate of one or more OFDM symbols for transmission on the sub-band (element 4020). For example, a PHY device of the PCR may pass two OOK symbols for each OFDM symbol duration (0.5x symbol duration) or may pass the OOK symbols at one OOK symbol for each OFDM symbol duration (lx symbol duration) to the radio and antenna array for transmission. In several embodiments, the wake-up preamble transmits at a fixed rate such as 62.5 kbps regardless of whether the rate negotiated for the remainder of the WUR packet is the same rate or a different rate.

Referring to FIG. 4B, the flowchart 4100 begins with a PCR of a device such as the PCR 1080 in FIG. 1 generating and transmitting, via an antenna array, an 802.11 preamble for an OFDMA packet on a channel (element 4110). The PCR may generate an 802.11 physical layer data unit (PPDU) as well as a wake-up radio (WUR) packet concurrently with transmission of the 802.11 preamble. After transmission of the 802.11 preamble, the PCR may transmit, via an antenna array, the remainder of the 802.11 PPDU on a first sub-band of the channel concurrently with transmission of the WUR packet on a second sub-band of the channel (element 4115). For example, the PCR may transmit the remainder of the 802.11 PPDU on a first sub-band of the channel at a high-efficiency transmission rate and may transmit the WUR packet at a rate of 250 kbps or 62.5 kbps.

FIGs. 4C-D depict embodiments of flowcharts 4200 and 4300 to transmit, receive, and interpret communications with a frame. Referring to FIG. 4A, the flowchart 4200 may begin with receiving a beacon frame. The MAC layer logic circuitry of the communications device may generate the frame as a management frame to transmit to other devices of a synch network and may pass the frame as an MAC protocol data unit (MPDU) to a PHY logic circuitry that transforms the data into a packet that can be transmitted to a STA. The PHY logic circuitry may generate a preamble to prepend the PHY service data unit (PSDU) (the MPDU from the frame builder) to form a PHY protocol data unit (PPDU) for transmission (element 4210). In some embodiments, more than one MPDU may be included in a PPDU.

The physical layer device such as the transmitter 306 in FIG. 3 or the wireless network interfaces 1022 and 1052 in FIG. 1 may convert the PPDU to a communication signal (element 4215). The transmitter may then transmit the communication signal via the antenna (element 4220).

Referring to FIG. 4D, the flowchart 4300 begins with a receiver of a device such as the receiver 304 in FIG. 3 receiving a communication signal via one or more antenna(s) such as an antenna element of antenna array 318 (element 4310). The receiver may convert the communication signal into an MPDU in accordance with the process described in the preamble (element 4315). More specifically, the received signal is fed from the one or more antennas to a DBF such as the DBF 220. The DBF transforms the antenna signals into information signals. The output of the DBF is fed to OFDM such as the OFDM 322 in FIG. 3. The OFDM extracts signal information from the plurality of subcarriers onto which information-bearing signals are modulated. Then, the demodulator such as the demodulator 324 demodulates the signal information via, e.g., BPSK, 16-QAM, 64-QAM, 256-QAM, QPSK, or SQPSK. And the decoder such as the decoder 326 decodes the signal information from the demodulator via, e.g., BCC or LDPC, to extract the MPDU and pass or communicate the MPDU to MAC layer logic such as MAC logic circuitry 301 (element 4320).

The MAC logic circuitry may determine frame field values from the MPDU (element 4325) such as the management frame fields. For instance, the MAC logic circuitry may determine frame field values such as the type and subtype field values of the synch frame. The MAC sublayer logic may determine that the MPDU comprises a synch frame so the synch logic may terminate an attempt to transmit a synch frame by the device.

Several embodiments comprise central servers, access points (APs), and/or stations (STAs) such as modems, routers, switches, servers, workstations, netbooks, mobile devices (Laptop, Smart Phone, Tablet, and the like), sensors, meters, controls, instruments, monitors, home or office appliances, Internet of Things (IoT) gear (watches, glasses, headphones, and the like), and the like. Some embodiments may provide, e.g., indoor and/or outdoor "smart" grid and sensor services. In various embodiments, these devices relate to specific applications such as healthcare, home, commercial office and retail, security, and industrial automation and monitoring applications, as well as vehicle applications (automobiles, self-driving vehicles, airplanes, and the like), and the like.

FIG. 5 illustrates an example of a storage medium 5000 to store pre-population logic such as one or more pre-population executables. Storage medium 5000 may comprise an article of manufacture. In some examples, storage medium 5000 may include any non-transitory computer readable medium or machine-readable medium, such as an optical, magnetic or semiconductor storage. Storage medium 5000 may store diverse types of computer executable instructions, such as instructions to implement logic flows and/or techniques described herein. Examples of a computer readable or machine-readable storage medium may include any tangible media capable of storing electronic data, including volatile memory or non-volatile memory, removable or nonremovable memory, erasable or non-erasable memory, writeable or re-writeable memory, and so forth. Examples of computer executable instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, object-oriented code, visual code, and the like.

FIG. 6 illustrates an example computing platform 6000 such as the STAs 1010, 1030, 1090,

1092, 1094, 1096, and 1098 in FIG. 1. In some examples, as shown in FIG. 6, computing platform 6000 may include a processing component 6010, other platform components or a communications interface 6030 such as the wireless network interfaces 1022 and 1052 shown in FIG. 1. According to some examples, computing platform 6000 may be a computing device such as a server in a system such as a data center or server farm that supports a manager or controller for managing configurable computing resources as mentioned above. Furthermore, the communications interface 6030 may comprise a wake-up radio (WUR) and may be capable of waking up a primary connectivity radio (PCR) of the computing platform 6000.

According to some examples, processing component 6010 may execute processing operations or logic for apparatus 6015 described herein. Processing component 6010 may include various hardware elements, software elements, or a combination of both. Examples of hardware elements may include devices, logic devices, components, processors, microprocessors, circuits, processor circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), memory units, logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. Examples of software elements, which may reside in the storage medium 6020, may include software components, programs, applications, computer programs, application programs, device drivers, system programs, software development programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. While discussions herein describe elements of embodiments as software elements and/or hardware elements, decisions to implement an embodiment using hardware elements and/or software elements may vary in accordance with any number of design considerations or factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other design or performance constraints.

In some examples, other platform components 6025 may include common computing elements, such as one or more processors, multi-core processors, co-processors, memory units, chipsets, controllers, peripherals, interfaces, oscillators, timing devices, video cards, audio cards, multimedia input/output (I/O) components (e.g., digital displays), power supplies, and so forth. Examples of memory units may include without limitation various types of computer readable and machine readable storage media in the form of one or more higher speed memory units, such as read-only memory (ROM), random-access memory (RAM), dynamic RAM (DRAM), Double- Data-Rate DRAM (DDR AM), synchronous DRAM (SDRAM), static RAM (SRAM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, polymer memory such as ferroelectric polymer memory, ovonic memory, phase change or ferroelectric memory, silicon-oxide-nitride-oxide- silicon (SONOS) memory, magnetic or optical cards, an array of devices such as Redundant Array of Independent Disks (RAID) drives, solid state memory devices (e.g., USB memory), solid state drives (SSD) and any other type of storage media suitable for storing information.

In some examples, communications interface 6030 may include logic and/or features to support a communication interface. For these examples, communications interface 6030 may include one or more communication interfaces that operate according to various communication protocols or standards to communicate over direct or network communication links. Direct communications may occur via use of communication protocols or standards described in one or more industry standards (including progenies and variants) such as those associated with the PCI Express specification. Network communications may occur via use of communication protocols or standards such as those described in one or more Ethernet standards promulgated by the Institute of Electrical and Electronics Engineers (IEEE). For example, one such Ethernet standard may include IEEE 802.3-2012, Carrier sense Multiple access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications, Published in December 2012 (hereinafter "IEEE 802.3"). Network communication may also occur according to one or more OpenFlow specifications such as the OpenFlow Hardware Abstraction API Specification. Network communications may also occur according to Infiniband Architecture Specification, Volume 1, Release 1.3, published in March 2015 ("the Infiniband Architecture specification").

Computing platform 6000 may be part of a computing device that may be, for example, a server, a server array or server farm, a web server, a network server, an Internet server, a work station, a mini-computer, a main frame computer, a supercomputer, a network appliance, a web appliance, a distributed computing system, multiprocessor systems, processor-based systems, or combination thereof. Accordingly, various embodiments of the computing platform 6000 may include or exclude functions and/or specific configurations of the computing platform 6000 described herein.

The components and features of computing platform 6000 may comprise any combination of discrete circuitry, ASICs, logic gates and/or single chip architectures. Further, the features of computing platform 6000 may comprise microcontrollers, programmable logic arrays and/or microprocessors or any combination of the foregoing where suitably appropriate. Note that hardware, firmware and/or software elements may be collectively or individually referred to herein as "logic".

One or more aspects of at least one example may comprise representative instructions stored on at least one machine -readable medium which represents various logic within the processor, which when read by a machine, computing device or system causes the machine, computing device or system to fabricate logic to perform the techniques described herein. Such representations, known as "IP cores" may be stored on a tangible, machine readable medium and supplied to various customers or manufacturing facilities to load into the fabrication machines that make the logic or processor.

Some examples may include an article of manufacture or at least one computer-readable medium. A computer-readable medium may include a non-transitory storage medium to store logic. In some examples, the non-transitory storage medium may include one or more types of computer-readable storage media capable of storing electronic data, including volatile memory or non- volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, and so forth. In some examples, the logic may include various software elements, such as software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, API, instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof.

According to some examples, a computer-readable medium may include a non-transitory storage medium to store or maintain instructions that when executed by a machine, computing device or system, cause the machine, computing device or system to perform methods and/or operations in accordance with the described examples. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. The instructions may be implemented according to a predefined computer language, manner, or syntax, for instructing a machine, computing device or system to perform a certain function. The instructions may be implemented using any suitable high-level, low-level, object-oriented, visual, compiled and/or interpreted programming language.

As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group( , and/or memory )shared , dedicated ,or group (that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality .

Various examples may be implemented using hardware elements, software elements, or a combination of both. In some examples, hardware elements may include devices, components, processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), memory units, logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. In some examples, software elements may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. Determining whether an example is implemented using hardware elements and/or software elements may vary in accordance with any number of factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other design or performance constraints, as desired for a given implementation.

Some examples may be described using the expression "in one example" or "an example" along with their derivatives. These terms mean that a particular feature, structure, or characteristic described in connection with the example is included in at least one example. The appearances of the phrase "in one example" in various places in the specification are not necessarily all referring to the same example.

Some examples may be described using the expression "coupled" and "connected" along with their derivatives. These terms are not necessarily intended as synonyms for each other. For example, descriptions using the terms "connected" and/or "coupled" may indicate that two or more elements are in direct physical or electrical contact with each other. The term "coupled," however, may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single example for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed examples require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed example. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate example. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein," respectively. Moreover, the terms "first," "second," "third," and so forth, are used merely as labels, and are not intended to impose numerical requirements on their objects.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code to reduce the number of times code must be retrieved from bulk storage during execution. The term "code" covers a broad range of software components and constructs, including applications, drivers, processes, routines, methods, modules, firmware, microcode, and subprograms. Thus, the term "code" may be used to refer to any collection of instructions which, when executed by a processing system, perform a desired operation or operations.

Logic circuitry, devices, and interfaces herein described may perform functions implemented in hardware and also implemented with code executed on one or more processors. Logic circuitry refers to the hardware or the hardware and code that implements one or more logical functions. Circuitry is hardware and may refer to one or more circuits. Each circuit may perform a particular function. A circuit of the circuitry may comprise discrete electrical components interconnected with one or more conductors, an integrated circuit, a chip package, a chip set, memory, or the like. Integrated circuits include circuits created on a substrate such as a silicon wafer and may comprise components. And integrated circuits, processor packages, chip packages, and chipsets may comprise one or more processors.

Processors may receive signals such as instructions and/or data at the input(s) and process the signals to generate the at least one output. While executing code, the code changes the physical states and characteristics of transistors that make up a processor pipeline. The physical states of the transistors translate into logical bits of ones and zeros stored in registers within the processor. The processor can transfer the physical states of the transistors into registers and transfer the physical states of the transistors to another storage medium.

A processor may comprise circuits to perform one or more sub-functions implemented to perform the overall function of the processor. One example of a processor is a state machine or an application-specific integrated circuit (ASIC) that includes at least one input and at least one output. A state machine may manipulate the at least one input to generate the at least one output by performing a predetermined series of serial and/or parallel manipulations or transformations on the at least one input.

The logic as described above may be part of the design for an integrated circuit chip. The chip design is created in a graphical computer programming language, and stored in a computer storage medium or data storage medium (such as a disk, tape, physical hard drive, or virtual hard drive such as in a storage access network). If the designer does not fabricate chips or the photolithographic masks used to fabricate chips, the designer transmits the resulting design by physical means (e.g., by providing a copy of the storage medium storing the design) or electronically (e.g., through the Internet) to such entities, directly or indirectly. The stored design is then converted into the appropriate format (e.g., GDSII) for the fabrication.

The resulting integrated circuit chips can be distributed by the fabricator in raw wafer form (that is, as a single wafer that has multiple unpackaged chips), as a bare die, or in a packaged form. In the latter case, the chip is mounted in a single chip package (such as a plastic carrier, with leads that are affixed to a motherboard or other higher- level carrier) or in a multichip package (such as a ceramic carrier that has either or both surface interconnections or buried interconnections). In any case, the chip is then integrated with other chips, discrete circuit elements, and/or other signal processing devices as part of either (a) an intermediate product, such as a processor board, a server platform, or a motherboard, or (b) an end product.

Several embodiments have one or more potentially advantages effects. For instance, generating a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols, advantageously facilitates a low power, low cost wake-up radio and wake-up radio packet transmissions as part of OFDMA transmissions to increase spectral utilization. Transmitting OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel advantageously facilitates a low power, low cost wake-up radio and wake-up radio packet transmissions as part of OFDMA transmissions to increase spectral utilization. Transmitting the wake-up packet by communicating symbols from the physical layer device to a radio coupled with the physical layer device, and communicating radio frequency signals from the radio to one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal advantageously facilitates a low power, low cost wake-up radio and wake-up radio packet transmissions as part of OFDMA transmissions to increase spectral utilization. Transmitting, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lxSymbol duration and/or 0.5xSymbol duration for the wake-up radio signal advantageously facilitates a low power, low cost wake-up radio and wake-up radio packet transmissions as part of OFDMA transmissions to increase spectral utilization.

EXAMPLES OF FURTHER EMBODIMENTS The following examples pertain to further embodiments. Specifics in the examples may be used anywhere in one or more embodiments.

Example 1 is an apparatus to communicate a wake-up radio packet, the apparatus comprising: medium access control (MAC) logic circuitry to generate a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and a physical layer device coupled with the MAC logic circuitry to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub- band of the channel. In Example 2, the apparatus of claim 1, further comprising a processor, a memory coupled with the processor, a radio coupled with the physical layer device, and one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 3, the apparatus of claim 1, wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency- division multiple access (OFDMA) modulated signal. In Example 4, the apparatus of claim 1, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 5, the apparatus of claim 1, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of half of an OFDM symbol at a lx symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 6, the apparatus of claim 1, the MAC logic circuitry to apply Manchester coding to the wake-up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols. In Example 7, the apparatus of claim 1, the apparatus to transmit, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lxSymbol duration for the wake-up radio signal. In Example 8, the apparatus of claim 1, wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence. In Example 9, the apparatus of claim 1, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second. In Example 10, the apparatus of claim 1, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

Example 11 is a method to communicate a wake-up radio packet, the method comprising: generating, by medium access control (MAC) logic circuitry, a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and communicating the wake-up radio packet to a physical layer device coupled with the MAC logic circuitry, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake- up radio packet on a sub-band of the channel. In Example 12, the method of claim 11, further comprising transmitting the wake-up radio packet by communicating symbols from the physical layer device to a radio coupled with the physical layer device, and communicating radio frequency signals from the radio to one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 13, the method of claim 11, wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 14, the method of claim 11, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 15, the method of claim 11, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of half of an OFDM symbol at a lx symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 16, the method of claim 11, further comprising applying Manchester coding to the wake-up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols. In Example 17, the method of claim 11, further comprising transmitting, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lxSymbol duration for the wake-up radio signal. In Example 18, the method of claim 11, wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence. In Example 19, the method of claim 11, wherein the rate of transmission of four OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second. In Example 20, the method of claim 11, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

Example 21 is a system to communicate a wake-up radio packet, the apparatus comprising: one or more antennas; a radio coupled with the one or more antennas; medium access control (MAC) logic circuitry to generate a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and a physical layer device coupled with the MAC logic circuitry and coupled with the radio to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel. In Example 22, the system of claim 21, further comprising a processor, a memory coupled with the processor. In Example 23, the system of claim 21, wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency- division multiple access (OFDMA) modulated signal. In Example 24, the system of claim 21, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 25, the system of claim 21, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of half of an OFDM symbol at a lx symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 26, the system of claim 21, the MAC logic circuitry to apply Manchester coding to the wake-up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols. In Example 27, the system of claim 21, wherein the system transmits, via the one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lx symbol duration for the wake-up radio signal. In Example 28, the system of claim 21, wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action pay load, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence. In Example 29, the system of claim 21, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second. In Example 30, the system of claim 21, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

Example 31 is a non-transitory computer-readable medium, comprising instructions to communicate a wake-up radio packet, which when executed by a processor, cause the processor to perform operations to: generate, by medium access control (MAC) logic circuitry, a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and communicate the wake-up radio packet to a physical layer device coupled with the MAC logic circuitry, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel. In Example 32, the non- transitory computer-readable medium of claim 31, wherein the operations further comprise operations to transmit the wake-up radio packet by communicating symbols from the physical layer device to a radio coupled with the physical layer device, and communicating radio frequency signals from the radio to one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 33, the non- transitory computer-readable medium of claim 31 , wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 34, the non-transitory computer-readable medium of claim 31, wherein the rate of transmission of four OOK symbols of the wake-up radio packet is set to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 35, the non- transitory computer- readable medium of claim 31, wherein the rate of transmission of one OOK symbol of the wake- up radio packet is set to the rate of transmission of half of an OFDM symbol at a lx symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 36, the non-transitory computer-readable medium of claim 31, wherein the operations to generate the wake-up radio packet comprise operations to apply, by MAC logic circuitry, Manchester coding to the wake-up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols. In Example 37, the non-transitory computer-readable medium of claim 31, wherein the MAC logic circuitry generates a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lxSymbol duration for the wake-up radio signal. In Example 38, the non-transitory computer-readable medium of claim 31, wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence. In Example 39, the non-transitory computer-readable medium of claim 31, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second. In Example 40, the non- transitory computer-readable medium of claim 31, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

Example 41 is an apparatus to communicate a wake-up radio packet, the apparatus comprising: a means for generating a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and a means for communicating the wake-up radio packet to a physical layer device coupled with the means for generating a wake-up radio packet, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel. In Example 42, the apparatus of claim 41, further comprising transmitting the wake- up radio packet by communicating symbols from the physical layer device to a radio coupled with the physical layer device, and communicating radio frequency signals from the radio to one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 43, the apparatus of claim 41, wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency-division multiple access (OFDMA) modulated signal. In Example 44, the apparatus of claim 41, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 45, the apparatus of claim 41, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is set to the rate of transmission of half of an OFDM symbol at a lx symbol duration, wherein the one OOK symbol includes a cyclic prefix. In Example 46, the apparatus of claim 41, further comprising a means for applying Manchester coding to the wake- up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols. In Example 47, the apparatus of claim 41, further comprising a means for transmitting, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lx symbol duration for the wake-up radio signal. In Example 48, the apparatus of claim 41, wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence. In Example 49, the apparatus of claim 41, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second. In Example 50, the apparatus of claim 41, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

In Example 51, the apparatus of Example 1, wherein the rate of transmission of a preamble of the wake-up radio packet is constant regardless of a rate for transmission negotiated for a remainder of the wake-up radio packet. In Example 52, the apparatus of Example 1, wherein the wake-up radio packet comprises a preamble sequence selected from different preamble sequences, to include in the wake-up radio packet to indicate a rate for transmission of at least a portion of the wake-up radio packet. In Example 53, the method of Example 11, wherein the rate of transmission of a preamble of the wake-up radio packet is constant regardless of a rate for transmission negotiated for a remainder of the wake-up radio packet. In Example 54, the method of Example 11, wherein the wake-up radio packet comprises a preamble sequence selected from different preamble sequences, to include in the wake-up radio packet to indicate a rate for transmission of at least a portion of the wake-up radio packet. In Example 55, the system of Example 21, wherein the rate of transmission of a preamble of the wake-up radio packet is constant regardless of a rate for transmission negotiated for a remainder of the wake-up radio packet. In Example 56, the system of Example 21, wherein the wake-up radio packet comprises a preamble sequence selected from different preamble sequences, to include in the wake-up radio packet to indicate a rate for transmission of at least a portion of the wake-up radio packet. In Example 57, the non-transitory computer-readable medium of Example 31, wherein the rate of transmission of a preamble of the wake-up radio packet is constant regardless of a rate for transmission negotiated for a remainder of the wake-up radio packet. In Example 58, the non-transitory computer-readable medium of Example 31, wherein the wake-up radio packet comprises a preamble sequence selected from different preamble sequences, to include in the wake-up radio packet to indicate a rate for transmission of at least a portion of the wake-up radio packet. In Example 59, the apparatus of Example 41, wherein the rate of transmission of a preamble of the wake-up radio packet is constant regardless of a rate for transmission negotiated for a remainder of the wake-up radio packet. In Example 60, the apparatus of Example 41 , wherein the wake-up radio packet comprises a preamble sequence selected from different preamble sequences, to include in the wake-up radio packet to indicate a rate for transmission of at least a portion of the wake-up radio packet.

Claims

WHAT IS CLAIMED IS:

An apparatus to communicate a wake-up radio packet, the apparatus comprising:

medium access control (MAC) logic circuitry to generate a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and

a physical layer device coupled with the MAC logic circuitry to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake- up radio packet on a sub-band of the channel.

The apparatus of claim 1, further comprising a processor, a memory coupled with the processor, a radio coupled with the physical layer device, and one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal.

The apparatus of claim 1, wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency-division multiple access (OFDMA) modulated signal.

The apparatus of claim 1, the MAC logic circuitry to apply Manchester coding to the wake- up radio packet, wherein each bit of information in the wake-up radio packet comprises two or four OOK symbols.

The apparatus of claim 1, the apparatus to transmit, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake- up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake- up radio packet, and an indication of support for transmission or receipt of lx symbol duration for the wake-up radio signal.

The apparatus of claim 1, wherein the wake-up radio packet comprises a preamble sequence selected from different preamble sequences, to include in the wake-up radio packet to indicate a rate for transmission of at least a portion of the wake-up radio packet.

The apparatus of claim 1, wherein the rate of transmission of a preamble of the wake-up radio packet is constant regardless of a rate for transmission negotiated for a remainder of the wake-up radio packet.

8. The apparatus of claim 1 , wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence.

9. The apparatus of claim 1 , wherein the rate of transmission of four OOK symbol of the wake- up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second.

10. The apparatus of claim 1, wherein the rate of transmission of two OOK symbols of the wake- up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

11. A method to communicate a wake-up radio packet, the method comprising:

generating, by medium access control (MAC) logic circuitry, a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and

communicating the wake-up radio packet to a physical layer device coupled with the MAC logic circuitry, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel.

12. The method of claim 11, further comprising transmitting the wake-up radio packet by communicating symbols from the physical layer device to a radio coupled with the physical layer device, and communicating radio frequency signals from the radio to one or more antennas coupled with the radio to transmit an orthogonal frequency-division multiple access (OFDMA) modulated signal.

13. The method of claim 11, further comprising transmitting, via one or more antennas, a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lx symbol duration for the wake-up radio signal.

14. The method of claim 11, wherein the wake-up radio packet comprises a preamble, a receiver identifier, an action identifier, an action payload, and a frame check sequence, wherein the preamble comprises two repetitions of a 16-bit sequence for transmission at a rate of 4 microseconds per bit for a total of 64 microseconds per sequence.

15. The method of claim 11, wherein the rate of transmission of one OOK symbol of the wake- up radio packet is equal to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second.

16. The method of claim 11, wherein the rate of transmission of two OOK symbols of the wake- up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

17. A non-transitory computer-readable medium, comprising instructions to communicate a wake-up radio packet, which when executed by a processor, cause the processor to perform operations to:

generate, by medium access control (MAC) logic circuitry, a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and

communicate the wake-up radio packet to a physical layer device coupled with the MAC logic circuitry, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake-up radio packet on a sub-band of the channel.

18. The non-transitory computer-readable medium of claim 17, wherein the wake-up radio packet comprises one or more resource units at a center of a multi-user, orthogonal frequency-division multiple access (OFDMA) modulated signal.

19. The non-transitory computer-readable medium of claim 17, wherein the operations to generate the wake-up radio packet comprise operations to apply, by MAC logic circuitry,

Manchester coding to the wake-up radio packet, wherein each bit of information in the wake- up radio packet comprises two or four OOK symbols.

20. The non-transitory computer-readable medium of claim 17, wherein the MAC logic circuitry generates a frame with one or more field values during association or reassociation of a station comprising a wake-up radio capability element, wherein the one or more field values comprise at least one of a supported rate for communication of the one or more OOK symbols, a supported format for communication of the wake-up radio packet, a tone location for communication of the wake-up radio packet, and an indication of support for transmission or receipt of lxSymbol duration for the wake-up radio signal.

21. The non-transitory computer-readable medium of claim 17, wherein the rate of transmission of one OOK symbol of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a 4x symbol duration, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second.

22. The non-transitory computer-readable medium of claim 17, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol at a lx symbol duration, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.

23. An apparatus to communicate a wake-up radio packet, the apparatus comprising:

a means for generating a wake-up radio packet, wherein the wake-up radio packet comprises an on-off keying (OOK) signal, wherein a rate of transmission of one or more OOK symbols of the wake-up radio packet is set to a rate of transmission of one or more orthogonal frequency-division multiplexing (OFDM) symbols; and a means for communicating the wake-up radio packet to a physical layer device coupled with the means for generating a wake-up radio packet, to transmit OFDM symbols of an IEEE 802.11 preamble on a channel followed by OOK symbols of the wake- up radio packet on a sub-band of the channel.

24. The apparatus of claim 23 , wherein the rate of transmission of one OOK symbol of the wake- up radio packet is equal to the rate of transmission of one OFDM symbol, wherein the rate of transmission of one OOK symbol is 62.5 kilobits per second.

25. The apparatus of claim 24, wherein the rate of transmission of two OOK symbols of the wake-up radio packet is equal to the rate of transmission of one OFDM symbol, wherein the rate of transmission of one OOK symbol is 250 kilobits per second.