Patent Publication Number: US-9848385-B2

Title: Apparatus, system and method of communicating a wakeup packet

Description:
CROSS REFERENCE 
     This application claims the benefit of and priority from U.S. Provisional Patent Application No. 62/162,766 entitled “Apparatus, System and Method of Communicating a Packet Including an On-Off Keying (OOK) Payload”, filed May 17, 2015, the entire disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Embodiments described herein generally relate to communicating a wakeup packet. 
     BACKGROUND 
     Some computing devices, for example, small computing devices, such as, for example, wearable devices and/or sensors, are constrained by a small battery capacity. 
     However, such devices may be required to support wireless communication technologies such as, for example, Wi-Fi, and/or Bluetooth (BT), for example, to connect to other computing devices, e.g., a Smartphone, for example, to exchange data. 
     Exchanging data using the wireless communication technologies may consume power of the battery, and it may be beneficial, or even critical, to minimize energy consumption of one or more communication blocks in such computing devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity of presentation. Furthermore, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. The figures are listed below. 
         FIG. 1  is a schematic block diagram illustration of a system, in accordance with some demonstrative embodiments. 
         FIG. 2  is a schematic illustration of a wakeup packet, in accordance with some demonstrative embodiments. 
         FIG. 3  is a schematic illustration of a plurality of Orthogonal-Frequency-Division Multiplexing (OFDM) tones of an On-Off Keying (OOK) transmit pulse, in accordance with some demonstrative embodiments. 
         FIG. 4  is a schematic illustration of an OOK transmit pulse, in accordance with some demonstrative embodiments. 
         FIG. 5  is a schematic illustration of a wakeup packet transmission, in accordance with some demonstrative embodiments. 
         FIG. 6  is a schematic flow-chart illustration of a method of communicating a wakeup packet, in accordance with some demonstrative embodiments. 
         FIG. 7  is a schematic illustration of a product of manufacture, in accordance with some demonstrative embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of some embodiments. However, it will be understood by persons of ordinary skill in the art that some embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, units and/or circuits have not been described in detail so as not to obscure the discussion. 
     Discussions herein utilizing terms such as, for example, “processing”, “computing”, “calculating”, “determining”, “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulate and/or transform data represented as physical (e.g., electronic) quantities within the computer&#39;s registers and/or memories into other data similarly represented as physical quantities within the computer&#39;s registers and/or memories or other information storage medium that may store instructions to perform operations and/or processes. 
     The terms “plurality” and “a plurality”, as used herein, include, for example, “multiple” or “two or more”. For example, “a plurality of items” includes two or more items. 
     References to “one embodiment”, “an embodiment”, “demonstrative embodiment”, “various embodiments” etc., indicate that the embodiment(s) so described may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase “in one embodiment” does not necessarily refer to the same embodiment, although it may. 
     As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third” etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. 
     Some embodiments may be used in conjunction with various devices and systems, for example, a User Equipment (UE), a Mobile Device (MD), a wireless station (STA), a Personal Computer (PC), a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, an Internet of Things (IoT) device, a sensor device, a wearable device, a Personal Digital Assistant (PDA) device, a handheld PDA device, an on-board device, an off-board device, a hybrid device, a vehicular device, a non-vehicular device, a mobile or portable device, a consumer device, a non-mobile or non-portable device, a wireless communication station, a wireless communication device, a wireless Access Point (AP), a wired or wireless router, a wired or wireless modem, a video device, an audio device, an audio-video (A/V) device, a wired or wireless network, a wireless area network, a Wireless Video Area Network (WVAN), a Local Area Network (LAN), a Wireless LAN (WLAN), a Personal Area Network (PAN), a Wireless PAN (WPAN), and the like. 
     Some embodiments may be used in conjunction with devices and/or networks operating in accordance with existing IEEE 802.11 standards (including IEEE 802.11-2012 ( IEEE  802.11-2012 , IEEE Standard for Information technology—Telecommunications and information exchange between systems Local and metropolitan area networks—Specific requirements Part  11 : Wireless LAN Medium Access Control  ( MAC )  and Physical Layer  ( PHY )  Specifications, Mar.  29, 2012);  IEEE 802.11 ac -2013 ( “IEEE P 802.11  ac -2013 , IEEE Standard for Information Technology—Telecommunications and Information Exchange Between Systems—Local and Metropolitan Area Networks—Specific Requirements—Part  11 : Wireless LAN Medium Access Control  ( MAC )  and Physical Layer  ( PHY )  Specifications—Amendment  4 : Enhancements for Very High Throughput for Operation in Bands below  6  GHz”, December,  2013);  IEEE  802.11 ad  ( “IEEE P 802.11 ad -2012 , IEEE Standard for Information Technology—Telecommunications and Information Exchange Between Systems—Local and Metropolitan Area Networks—Specific Requirements—Part  11 : Wireless LAN Medium Access Control  ( MAC )  and Physical Layer  ( PHY )  Specifications—Amendment  3 : Enhancements for Very High Throughput in the  60  GHz Band”,  28  Dec.  2012);  IEEE -802.11 REVmc  ( “IEEE  802.11- REVmcm/D 3.0 , June  2014  draft standard for Information technology—Telecommunications and information exchange between systems Local and metropolitan area networks Specific requirements; Part  11 : Wireless LAN Medium Access Control  ( MAC )  and Physical Layer  ( PHY )  Specification ”);  IEEE  802.11 ax  ( IEEE  802.11 ax, High Efficiency WLAN  ( HEW )); IEEE802.11- ay  ( P 802.11 ay Standard for Information Technology—Telecommunications and Information Exchange Between Systems Local and Metropolitan Area Networks—Specific Requirements Part  11 : Wireless IAN Medium Access Control  ( MAC )  and Physical Layer  ( PHY )  Specifications—Amendment: Enhanced Throughput for Operation in License - Exempt Bands Above  45  GHz )) and/or future versions and/or derivatives thereof) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing Wireless-Gigabit-Alliance (WGA) specifications ( Wireless Gigabit Alliance, Inc WiGig MAC and PHY Specification Version  1.1 , April  2011 , Final specification ) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing Wireless Fidelity (WiFi) Alliance (WFA) Peer-to-Peer (P2P) specifications (WiFi P2P technical specification, version 1.5, Aug. 4, 2014) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing cellular specifications and/or protocols, e.g., 3rd Generation Partnership Project (3GPP), 3GPP Long Term Evolution (LTE) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing Bluetooth (BT) specifications and/or protocols and/or future versions and/or derivatives thereof, units and/or devices which are part of the above networks, and the like. 
     Some embodiments may be used in conjunction with one way and/or two-way radio communication systems, cellular radio-telephone communication systems, a mobile phone, a cellular telephone, a wireless telephone, a Personal Communication Systems (PCS) device, a PDA device which incorporates a wireless communication device, a mobile or portable Global Positioning System (GPS) device, a device which incorporates a GPS receiver or transceiver or chip, a device which incorporates an RFID element or chip, a Multiple Input Multiple Output (MIMO) transceiver or device, a Single Input Multiple Output (SIMO) transceiver or device, a Multiple Input Single Output (MISO) transceiver or device, a device having one or more internal antennas and/or external antennas, Digital Video Broadcast (DVB) devices or systems, multi-standard radio devices or systems, a wired or wireless handheld device, e.g., a Smartphone, a Wireless Application Protocol (WAP) device, or the like. 
     Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems, for example, Radio Frequency (RF), Infra Red (IR), Frequency-Division Multiplexing (FDM), Orthogonal FDM (OFDM), Orthogonal Frequency-Division Multiple Access (OFDMA), FDM Time-Division Multiplexing (TDM), Time-Division Multiple Access (TDMA), Multi-User MIMO (MU-MIMO), Spatial Division Multiple Access (SDMA), Extended TDMA (E-TDMA), General Packet Radio Service (GPRS), extended GPRS, Code-Division Multiple Access (CDMA), Wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA, Multi-Carrier Modulation (MDM), Discrete Multi-Tone (DMT), Bluetooth®, Global Positioning System (GPS), Wi-Fi, Wi-Max, ZigBee™, Ultra-Wideband (UWB), Global System for Mobile communication (GSM), 2G, 2.5G, 3G, 3.5G, 4G, Fifth Generation (5G), or Sixth Generation (6G) mobile networks, 3GPP, Long Term Evolution (LTE), LTE advanced, Enhanced Data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems and/or networks. 
     The term “wireless device”, as used herein, includes, for example, a device capable of wireless communication, a communication device capable of wireless communication, a communication station capable of wireless communication, a portable or non-portable device capable of wireless communication, or the like. In some demonstrative embodiments, a wireless device may be or may include a peripheral that is integrated with a computer, or a peripheral that is attached to a computer. In some demonstrative embodiments, the term “wireless device” may optionally include a wireless service. 
     The term “communicating” as used herein with respect to a communication signal includes transmitting the communication signal and/or receiving the communication signal. For example, a communication unit, which is capable of communicating a communication signal, may include a transmitter to transmit the communication signal to at least one other communication unit, and/or a communication receiver to receive the communication signal from at least one other communication unit. The verb communicating may be used to refer to the action of transmitting or the action of receiving. In one example, the phrase “communicating a signal” may refer to the action of transmitting the signal by a first device, and may not necessarily include the action of receiving the signal by a second device. In another example, the phrase “communicating a signal” may refer to the action of receiving the signal by a first device, and may not necessarily include the action of transmitting the signal by a second device. 
     As used herein, the term “circuitry” may refer to, be part of, or include, an Application Specific Integrated Circuit (ASIC), an integrated circuit, an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, group or), that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware. 
     Some demonstrative embodiments may be used in conjunction with a WLAN, e.g., a WiFi network. Other embodiments may be used in conjunction with any other suitable wireless communication network, for example, a wireless area network, a “piconet”, a WPAN, a WVAN and the like. 
     The term “antenna”, as used herein, may include any suitable configuration, structure and/or arrangement of one or more antenna elements, components, units, assemblies and/or arrays. In some embodiments, the antenna may implement transmit and receive functionalities using separate transmit and receive antenna elements. In some embodiments, the antenna may implement transmit and receive functionalities using common and/or integrated transmit/receive elements. The antenna may include, for example, a phased array antenna, a single element antenna, a set of switched beam antennas, and/or the like. 
     Reference is made to  FIG. 1 , which schematically illustrates a system  100 , in accordance with some demonstrative embodiments. 
     As shown in  FIG. 1 , in some demonstrative embodiments, system  100  may include one or more wireless communication devices. For example, system  100  may include a first wireless communication device  102 , and/or a second wireless communication device  140 . 
     In some demonstrative embodiments, device  102  and/or device  140  may include a mobile device or a non-mobile, e.g., a static, device. For example, device  102  and/or device  140  may include, for example, a UE, an MD, a STA, an AP, a PC, a desktop computer, a mobile computer, a laptop computer, an Ultrabook™ computer, a notebook computer, a tablet computer, a server computer, a handheld computer, an Internet of Things (IoT) device, sensor device, a wearable device, a BT device, a handheld device, a PDA device, a handheld PDA device, an on-board device, an off-board device, a hybrid device (e.g., combining cellular phone functionalities with PDA device functionalities), a consumer device, a vehicular device, a non-vehicular device, a mobile or portable device, a non-mobile or non-portable device, a mobile phone, a cellular telephone, a PCS device, a PDA device which incorporates a wireless communication device, a mobile or portable GPS device, a DVB device, a relatively small computing device, a non-desktop computer, a “Carry Small Live Large” (CSLL) device, an Ultra Mobile Device (UMD), an Ultra Mobile PC (UMPC), a Mobile Internet Device (MID), an “Origami” device or computing device, a device that supports Dynamically Composable Computing (DCC), a context-aware device, a video device, an audio device, an A/V device, a Set-Top-Box (STB), a Blu-ray disc (BD) player, a BD recorder, a Digital Video Disc (DVD) player, a High Definition (HD) DVD player, a DVD recorder, a HD DVD recorder, a Personal Video Recorder (PVR), a broadcast HD receiver, a video source, an audio source, a video sink, an audio sink, a stereo tuner, a broadcast radio receiver, a flat panel display, a Personal Media Player (PMP), a digital video camera (DVC), a digital audio player, a speaker, an audio receiver, an audio amplifier, a gaming device, a data source, a data sink, a Digital Still camera (DSC), a media player, a Smartphone, a television, a music player, or the like. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of one or more STAs. For example, device  102  may include at least one STA, and/or device  140  may include at least one STA. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of one or more WLAN STAs. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of one or more Wi-Fi STAs. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of one or more BT devices. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of one or more Neighbor Awareness Networking (NAN) STAs. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of one or more location measurement STAs. 
     In some demonstrative embodiments, device  102  and/or device  140  may include, operate as, and/or perform the functionality of any other devices and/or STAs. 
     In some demonstrative embodiments, device  102  may include, for example, one or more of a processor  191 , an input unit  192 , an output unit  193 , a memory unit  194 , and/or a storage unit  195 ; and/or device  140  may include, for example, one or more of a processor  181 , an input unit  182 , an output unit  183 , a memory unit  184 , and/or a storage unit  185 . Device  102  and/or device  140  may optionally include other suitable additional or alternative hardware components and/or software components. In some demonstrative embodiments, some or all of the components of one or more of device  102  and/or device  140  may be enclosed in a common housing or packaging, and may be interconnected or operably associated using one or more wired or wireless links. In other embodiments, components of one or more of device  102  and/or device  140  may be distributed among multiple or separate devices. 
     In some demonstrative embodiments, processor  191  and/or processor  181  may include, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), one or more processor cores, a single-core processor, a dual-core processor, a multiple-core processor, a microprocessor, a host processor, a controller, a plurality of processors or controllers, a chip, a microchip, one or more circuits, circuitry, a logic unit, an Integrated Circuit (IC), an Application-Specific IC (ASIC), or any other suitable multi-purpose or specific processor or controller. Processor  191  executes instructions, for example, of an Operating System (OS) of device  102  and/or of one or more suitable applications. Processor  181  executes instructions, for example, of an Operating System (OS) of device  140  and/or of one or more suitable applications. 
     In some demonstrative embodiments, input unit  192  and/or input unit  182  may include, for example, a keyboard, a keypad, a mouse, a touch-screen, a touch-pad, a track-ball, a stylus, a microphone, or other suitable pointing device or input device. Output unit  193  and/or output unit  183  may include, for example, a monitor, a screen, a touch-screen, a flat panel display, a Light Emitting Diode (LED) display unit, a Liquid Crystal Display (LCD) display unit, a plasma display unit, one or more audio speakers or earphones, or other suitable output devices. 
     In some demonstrative embodiments, memory unit  194  and/or memory unit  184  may include, for example, a Random Access Memory (RAM), a Read Only Memory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM (SD-RAM), a flash memory, a volatile memory, a non-volatile memory, a cache memory, a buffer, a short term memory unit, a long term memory unit, or other suitable memory units. Storage unit  195  and/or storage unit  185  may include, for example, a hard disk drive, a floppy disk drive, a Compact Disk (CD) drive, a CD-ROM drive, a DVD drive, or other suitable removable or non-removable storage units. Memory unit  194  and/or storage unit  195 , for example, may store data processed by device  102 . Memory unit  184  and/or storage unit  185 , for example, may store data processed by device  140 . 
     In some demonstrative embodiments, wireless communication device  102  and/or device  140  may be capable of communicating content, data, information and/or signals via a wireless medium (WM)  103 . In some demonstrative embodiments, wireless medium  103  may include, for example, a radio channel, a cellular channel, an RF channel, a WiFi channel, an IR channel, a Bluetooth (BT) channel, a Global Navigation Satellite System (GNSS) Channel, and the like. 
     In some demonstrative embodiments, WM  103  may include a channel over a 2.4 Gigahertz (GHz) frequency band, a channel over a 5 GHz frequency band, a channel over a millimeterWave (mmWave) frequency band, e.g., a 60 GHz frequency band, a channel over a sub 1 Gigahertz (S1G) frequency band, and/or any other channel over any other band. 
     In some demonstrative embodiments, device  102  and/or device  140  may include one or more radios including circuitry and/or logic to perform wireless communication between devices  102 ,  140  and/or one or more other wireless communication devices. For example, device  102  may include at least one radio  114 , and/or device  140  may include at least one radio  144 . 
     In some demonstrative embodiments, radios  114  and/or  144  may include one or more wireless receivers (Rx) including circuitry and/or logic to receive wireless communication signals, RF signals, frames, blocks, transmission streams, packets, messages, data items, and/or data. For example, radio  114  may include at least one receiver  116 , and/or radio  144  may include at least one receiver  146 . 
     In some demonstrative embodiments, radios  114  and/or  144  may include one or more wireless transmitters (Tx) including circuitry and/or logic to transmit wireless communication signals, RF signals, frames, blocks, transmission streams, packets, messages, data items, and/or data. For example, radio  114  may include at least one transmitter  118 , and/or radio  144  may include at least one transmitter  148 . 
     In some demonstrative embodiments, radio  114 , radio  144 , transmitter  118 , transmitter  148 , receiver  116 , and/or receiver  148  may include circuitry; logic; Radio Frequency (RF) elements, circuitry and/or logic; baseband elements, circuitry and/or logic; modulation elements, circuitry and/or logic; demodulation elements, circuitry and/or logic; amplifiers; analog to digital and/or digital to analog converters; filters; and/or the like. For example, radios  114  and/or  144  may include or may be implemented as part of a wireless Network Interface Card (NIC), and the like. 
     In some demonstrative embodiments, radios  114  and/or  144  may be configured to communicate according to an OFDM scheme. For example, radios  114  and/or  144  may include an OFDM receiver and/or an OFDM transmitter. In other embodiments, radios  114  and/or  144  may be configured to communicate with any other additional or alternative modulation scheme. 
     In some demonstrative embodiments, radios  114  and/or  144  may include, or may be associated with, one or more antennas  107  and/or  147 , respectively. 
     In one example, device  102  may include a single antenna  107 . In another example, device  102  may include two or more antennas  107 . 
     In one example, device  140  may include a single antenna  147 . In another example, device  140  may include two or more antennas  147 . 
     Antennas  107  and/or  147  may include any type of antennas suitable for transmitting and/or receiving wireless communication signals, blocks, frames, transmission streams, packets, messages and/or data. For example, antennas  107  and/or  147  may include any suitable configuration, structure and/or arrangement of one or more antenna elements, components, units, assemblies and/or arrays. Antennas  107  and/or  147  may include, for example, antennas suitable for directional communication, e.g., using beamforming techniques. For example, antennas  107  and/or  147  may include a phased array antenna, a multiple element antenna, a set of switched beam antennas, and/or the like. In some embodiments, antennas  107  and/or  147  may implement transmit and receive functionalities using separate transmit and receive antenna elements. In some embodiments, antennas  107  and/or  147  may implement transmit and receive functionalities using common and/or integrated transmit/receive elements. 
     In some demonstrative embodiments, device  102  may include a controller  124 , and/or device  140  may include a controller  154 . Controllers  124  and/or  154  may be configured to perform one or more communications, may generate and/or communicate one or more messages and/or transmissions, and/or may perform one or more functionalities, operations and/or procedures between devices  102 , and/or  140  and/or one or more other devices, e.g., as described below. 
     In some demonstrative embodiments, controllers  124  and/or  154  may include circuitry and/or logic, e.g., one or more processors including circuitry and/or logic, memory circuitry and/or logic, Media-Access Control (MAC) circuitry and/or logic, Physical Layer (PHY) circuitry and/or logic, and/or any other circuitry and/or logic, configured to perform the functionality of controllers  124  and/or  154 , respectively. Additionally or alternatively, one or more functionalities of controllers  124  and/or  154  may be implemented by logic, which may be executed by a machine and/or one or more processors, e.g., as described below. 
     In one example, controller  124  may include circuitry and/or logic, for example, one or more processors including circuitry and/or logic, to cause, trigger and/or control a wireless device, e.g., device  102 , and/or a wireless station, e.g., a wireless STA implemented by device  102 , to perform one or more operations, communications and/or functionalities, e.g., as described herein. 
     In one example, controller  154  may include circuitry and/or logic, for example, one or more processors including circuitry and/or logic, to cause, trigger and/or control a wireless device, e.g., device  140 , and/or a wireless station, e.g., a wireless STA implemented by device  140 , to perform one or more operations, communications and/or functionalities, e.g., as described herein. 
     In some demonstrative embodiments, device  102  may include a message processor  128  configured to generate, process and/or access one or messages communicated by device  102 . 
     In one example, message processor  128  may be configured to generate one or more messages to be transmitted by device  102 , and/or message processor  128  may be configured to access and/or to process one or more messages received by device  102 , e.g., as described below. 
     In some demonstrative embodiments, device  140  may include a message processor  158  configured to generate, process and/or access one or messages communicated by device  140 . 
     In one example, message processor  158  may be configured to generate one or more messages to be transmitted by device  140 , and/or message processor  158  may be configured to access and/or to process one or more messages received by device  140 , e.g., as described below. 
     In some demonstrative embodiments, message processors  128  and/or  158  may include circuitry and/or logic, e.g., one or more processors including circuitry and/or logic, memory circuitry and/or logic, Media-Access Control (MAC) circuitry and/or logic, Physical Layer (PHY) circuitry and/or logic, and/or any other circuitry and/or logic, configured to perform the functionality of message processors  128  and/or  158 , respectively. Additionally or alternatively, one or more functionalities of message processors  128  and/or  158  may be implemented by logic, which may be executed by a machine and/or one or more processors, e.g., as described below. 
     In some demonstrative embodiments, at least part of the functionality of message processor  128  may be implemented as part of radio  114 , and/or at least part of the functionality of message processor  158  may be implemented as part of radio  144 . 
     In some demonstrative embodiments, at least part of the functionality of message processor  128  may be implemented as part of controller  124 , and/or at least part of the functionality of message processor  158  may be implemented as part of controller  154 . 
     In other embodiments, the functionality of message processor  128  may be implemented as part of any other element of device  102 , and/or the functionality of message processor  158  may be implemented as part of any other element of device  140 . 
     In some demonstrative embodiments, at least part of the functionality of controller  124  and/or message processor  128  may be implemented by an integrated circuit, for example, a chip, e.g., a System on Chip (SoC). In one example, the chip or SoC may be configured to perform one or more functionalities of radio  114 . For example, the chip or SoC may include one or more elements of controller  124 , one or more elements of message processor  128 , and/or one or more elements of radio  114 . In one example, controller  124 , message processor  128 , and radio  114  may be implemented as part of the chip or SoC. 
     In other embodiments, controller  124 , message processor  128  and/or radio  114  may be implemented by one or more additional or alternative elements of device  102 . 
     In some demonstrative embodiments, device  102  and/or device  140  may include a wearable device, a sensor, small device, a mobile device, and/or any other device, which may be, for example, powered by a battery and/or any other power source having a limited capacity. 
     In some demonstrative embodiments, device  102  and/or device  140  may support wireless communication technologies such as, for example, Wi-Fi, Bluetooth (BT), and/or any other additional or alternative technology, for example, to connect between device  102 , device  140 , and/or other wireless devices. 
     In some demonstrative embodiments, device  140  may include a wearable device and/or a sensor device powered by a power source having a limited capacity, e.g., a small battery. 
     In some demonstrative embodiments, device  140  may be configured to communicate data with another device, e.g., device  102 , which may be less power constrained than device  140 , for example, a Smartphone. 
     In some demonstrative embodiments, communicating data between device  102  and device  140  may consume power of the power source of device  140 . 
     In some demonstrative embodiments, minimizing energy consumption of one or more communication blocks, modules and/or elements of device  140  may be beneficial, and in some cases, even critical, for example, in order to reduce and/or minimize power consumption of the power source of device  140 . 
     In some demonstrative embodiments, power consumption of device  140  may be reduced, e.g., minimized, for example, by powering off one or more communication blocks, modules and/or elements of device  140 , e.g., as much as possible, for example, while maintaining data transmission and/or reception capabilities of device  140 , e.g., without substantially increasing latency and/or degrading quality of data communication. 
     In one example, one or more communication blocks, modules and/or elements of device  140  may be powered on and/or may be woken up, for example, only when there is data to transmit, and/or only when there is data to receive. According to this example, the one or more communication blocks, modules and/or elements of device  140  may be powered off and/or switched to a sleep mode, for example, for the rest of the time. 
     For example, one or more elements of radio  144  may be powered on and/or may be woken up, for example, only when device  140  has data to transmit, and/or only when device  140  has data to receive. According to this example, one or more elements of radio  144  may be powered off and/or switched to the sleep mode, for example, for the rest of the time. 
     In some demonstrative embodiments, device  140  may include a wakeup receiver  150  configured to power on and/or to wakeup radio  144  of device  140 . 
     In some demonstrative embodiments, wakeup receiver  150  may wake up radio  144 , for example, based on a packet, e.g., a wakeup packet, received from another device, e.g., device  102 , which is, for example, to transmit data to device  140 . 
     In some demonstrative embodiments, wakeup receiver  150  may include a receiver  156  configured to receive the wakeup packet. 
     In some demonstrative embodiments, wakeup receiver  150  may include circuitry and/or logic configured to receive, decode, demodulate, and/or process the wakeup packet. 
     In some demonstrative embodiments, receiver  156  may include circuitry; logic; Radio Frequency (RF) elements, circuitry and/or logic; baseband elements, circuitry and/or logic; demodulation elements, circuitry and/or logic; amplifiers; analog to digital converters; filters; and/or the like. 
     In some demonstrative embodiments, wakeup receiver  150  may include a controller  159  configured to control one or more operations and/or functionalities of wakeup receiver  150 , e.g., for processing the wakeup packet and/or waking up radio  144 . For example, controller  159  may be configured to control a power supply of radio  144 , and/or any other mechanism to wakeup radio  144 , e.g., upon determining that a wakeup packet has been received by wakeup receiver  150 . 
     In some demonstrative embodiments, controller  159  may be configured to perform one or more communications, to generate and/or communicate one or more messages and/or transmissions, and/or to perform one or more functionalities, operations and/or procedures, e.g., as described below. 
     In some demonstrative embodiments, controller  159  may include circuitry and/or logic, e.g., one or more processors including circuitry and/or logic, memory circuitry and/or logic, Media-Access Control (MAC) circuitry and/or logic, Physical Layer (PHY) circuitry and/or logic, and/or any other circuitry and/or logic, configured to perform the functionality of controller  159 . Additionally or alternatively, one or more functionalities of controller  159  may be implemented by logic, which may be executed by a machine and/or one or more processors, e.g., as described below. 
     In one example, controller  159  may include circuitry and/or logic, for example, one or more processors including circuitry and/or logic, to cause a wireless device, e.g., device  140 , and/or a wireless station, e.g., a wireless STA implemented by device  140 , to perform one or more operations, communications and/or functionalities, e.g., as described herein. 
     In some demonstrative embodiments, wakeup receiver  150  may include a message processor  157  configured to process and/or access one or messages communicated by wakeup receiver  150 . 
     In some demonstrative embodiments, message processor  157  may be configured to process one or more wakeup packets received by wakeup receiver  150 , and/or to indicate to controller  159  that a wakeup packet is received. 
     In one example, message processor  157  may be configured to access, process, demodulate and/or decode reception of the wakeup packets by a wireless station, e.g., a wireless STA implemented by device  140 . 
     In some demonstrative embodiments, message processor  157  may include circuitry and/or logic, e.g., one or more processors including circuitry and/or logic, memory circuitry and/or logic, Media-Access Control (MAC) circuitry and/or logic, Physical Layer (PHY) circuitry and/or logic, and/or any other circuitry and/or logic, configured to perform the functionality of message processor  157 . Additionally or alternatively, one or more functionalities of message processor  157  may be implemented by logic, which may be executed by a machine and/or one or more processors, e.g., as described below. 
     In some demonstrative embodiments, at least part of the functionality of message processor  157  may be implemented as part of message processor  158 . 
     In some demonstrative embodiments, at least part of the functionality of message processor  157  may be implemented as part of any other element of wakeup receiver  150 . For example, at least part of the functionality of message processor  157  may be implemented as part of receiver  156  and/or controller  159 . 
     In some demonstrative embodiments, at least part of the functionality of receiver  156 , controller  159  and/or message processor  157  may be implemented by an integrated circuit, for example, a chip, e.g., a System on Chip (SoC). In one example, the chip or SoC may be configured to perform one or more functionalities of radio  144 , controller  154  and/or message processor  158 . For example, the chip or SoC may include one or more elements of controller  159 , one or more elements of message processor  157 , and/or one or more elements of receiver  156 , one or more elements of radio  144 , one or more elements of message processor  158 , and/or one or more elements of controller  154 . In one example, wakeup receiver  150 , message processor  158 , controller  154 , and/or radio  144  may be implemented as part of the chip or SoC. 
     In other embodiments, radio  144 , wakeup receiver  150 , controller  154  and/or message processor  158  may be implemented by one or more additional or alternative elements of device  140 . 
     In some demonstrative embodiments, wakeup receiver  150  may be associated with one or more of antennas  147 , e.g., which may be shared with radio  144 . 
     In other embodiments, wakeup receiver  150  may include, or may be associated with, another, e.g., separate, antenna. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured to wake up radio  144 , for example, if device  140  has data to transmit, and/or if data is to be received by radio  144 . 
     In one example, wakeup receiver  150  may be configured to implement a low-power wakeup receiver (LP-WUR) scheme, for example, to wakeup radio  144 , e.g., only when device  140  is to receive data and/or to transmit data. 
     In some demonstrative embodiments, wakeup receiver  150  may have, for example, a relatively low power consumption, e.g., less than 100 microwatts. Accordingly, the power consumption of device  140  may be reduced for example, during times when there is no data to be received at device  140  and only wakeup receiver  150  is on. 
     In some demonstrative embodiments, wakeup receiver  150  may wake up radio  144 , for example, based on a wakeup packet received from device  102 . 
     In one example, receiver  156  may be configured to receive the wakeup packet from device  102 , message processor  156  may be configured to process the wakeup packet, and/or controller  159  may be configured to wake up radio  144 . 
     In some demonstrative embodiments, device  140  may be configured to transmit the wakeup packet to device  102 , for example, to indicate to wakeup receiver  150  that the radio  144  is to be woken up, e.g., to receive data from device  102 . 
     In some demonstrative embodiments, controller  159  may be configured to cause radio  144  to wake up, e.g., to switch to an active mode, for example, to receive data from device  102 , e.g., subsequent to receiving the wakeup packet from device  102 . 
     In some demonstrative embodiments, controller  159  may be configured to cause, control and/or trigger radio  144  to wake up, e.g., to switch to an active mode, for example, to transmit data to device  102  and/or to another device. 
     In some demonstrative embodiments, device  102  and/or device  140  may be configured to communicate the wakeup packet, for example, in compliance with one or more wireless communication standards and/or protocols. 
     In some demonstrative embodiments, device  102  and/or device  140  may be configured to communicate the wakeup packet, for example, in compliance with one or more existing wireless communication standards and/or protocols (“legacy standards”), for example, in compliance with one or more IEEE 802.11 standards. 
     In some demonstrative embodiments, the wakeup packet may include a preamble (“legacy preamble”) in compliance with one or more legacy standards. 
     In some demonstrative embodiments, the wakeup packet may include a preamble in compliance with one or more legacy standards, for example, to enable one or more legacy devices to decode and/or process the preamble. 
     In some demonstrative embodiments, the wakeup packet may include a payload, e.g., following the legacy preamble. 
     In some demonstrative embodiments, the payload may be modulated by a simple modulation scheme, for example, an On-Off Keying (OOK) modulation scheme. 
     Some demonstrative embodiments are described herein with respect to an OOK modulation scheme. However, in other embodiments the wakeup packet may include a payload modulated according to any other Amplitude-Shift Keying (ASK) modulation scheme, a Frequency Shift Keying (FSK) modulation scheme, and/or any other modulation scheme. 
     In some demonstrative embodiments, using a dedicated OOK transmitter to modulate the payload may not be efficient. 
     In one example, it may not be efficient and/or advantageous to generate the wakeup packet using a separate wakeup packet transmitter with an OOK modulator. For example, in such implementation a device (“transmitter device”), transmitting the wakeup packet, e.g., device  102 , may be required to have two separate transmit modules, for example, a first transmit module, for example, an OFDM transmitter, e.g., radio  114 , in compliance with the IEEE 802.11 standards, and a second transmitter, e.g., an OOK transmitter, to transmit the payload of the wakeup packet. 
     In some demonstrative embodiments, the transmitter device, e.g., device  102 , may be configured to generate a wakeup packet, for example, by reusing an OFDM transmitter, e.g., a transmitter in compliance with the IEEE 802.11 standards. 
     In some demonstrative embodiments, the transmitter device, e.g., device  102 , may be configured to use the same transmitter, for example, an OFDM transmitter, e.g., radio  114 , for example, to generate the wakeup packet including both the legacy preamble, which may be modulated using the OFDM modulation scheme, and the payload, e.g., which may be modulated using the OOK modulation scheme. 
     In some demonstrative embodiments, the transmitter device, e.g., device  102 , may be configured to generate a wakeup packet, for example, without needing to use a dedicated transmit module, e.g., a dedicated OOK transmit module. 
     In some demonstrative embodiments, device  102 , may be configured to use transmitter  118  of radio  114 , for example, to generate the wakeup packet including both the legacy preamble and the wakeup payload, for example, without needing to use two separate transmit modules, e.g., as described below. 
     In some demonstrative embodiments, device  102  and/or device  140  may be configured to communicate a wakeup packet using a wakeup radio pulse design, which may be, for example, uniquely enabled by the re-use of the OFDM transmitter, e.g., as described below. 
     In some demonstrative embodiments, device  102  may generate a wakeup packet including a preamble and a payload. 
     In one example, controller  124  may cause, trigger and/or control message generator  128  to generate the wakeup packet. 
     In some demonstrative embodiments, controller  124  may be configured to cause, control, and/or trigger radio  114  to modulate the preamble of the wakeup packet according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme, e.g., as described below. 
     In some demonstrative embodiments, controller  124  may be configured to cause, control, and/or trigger radio  114  to modulate the payload of the wakeup packet according to the OOK modulation scheme over a plurality of OFDM tones of the OFDM scheme, e.g., as described below. 
     In some demonstrative embodiments, radio  114  may transmit the wakeup packet to device  140 . 
     In some demonstrative embodiments, wakeup receiver  150  may receive the wakeup packet. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured to demodulate the preamble of the wakeup packet from device  102  according to the OFDM scheme. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured to demodulate the payload of the wakeup packet according to the OOK modulation scheme over the plurality of the OFDM tones of the OFDM scheme. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured activate radio  154  of device  140 , for example, based on the payload of the wakeup packet, e.g., as described below. 
     In some demonstrative embodiments, the payload of the wakeup packet may include a plurality of payload values, for example, a predefined sequence of values, which may be configured to indicate that the packet is a wakeup packet, e.g., as described below with reference to  FIG. 2 . For example, wakeup receiver  150  may be configured to decode the payload of a received packet, and to determine that the received packet is a wakeup packet, for example, if the payload include the predefined sequence of values. 
     In some demonstrative embodiments, controller  124  and/or message processor  128  may be configured to set a signal field in the preamble to indicate at least a duration of the payload. 
     In some demonstrative embodiments, controller  124  and/or message processor  128  may be configured to set a rate field and a length field in the signal field, for example, based on a number of the plurality of OFDM tones, and a number of OOK bits in the payload, e.g., as described below with reference to  FIG. 2 . 
     Reference is made to  FIG. 2 , which schematically illustrates a wakeup packet  200 , in accordance with some demonstrative embodiments. 
     In one example, device  102  ( FIG. 1 ) may transmit wakeup packet  200  to device  140  ( FIG. 1 ), for example, to indicate to wakeup receiver  150  ( FIG. 1 ) that radio  144  ( FIG. 1 ) is to be woken up. 
     In some demonstrative embodiments, message processor  128  ( FIG. 1 ), may be configured to construct and/or generate wakeup packet  200 . 
     As shown in  FIG. 2 , wakeup packet  200  may include a preamble  220  (“Legacy Preamble”) and a payload  230 . 
     In some demonstrative embodiments, preamble  220  may include, for example, a preamble construction in compliance with an IEEE 802.11 standard (“Legacy 802.11 preamble construction”). 
     As shown in  FIG. 2 , preamble  220  may include a legacy short training field (L-STF)  222 , for example, based on the IEEE 802.11-2012 standard, e.g., according to section 18.3.3 (PLCP preamble), and/or in accordance with any other section and/or of any other Standard. 
     As shown in  FIG. 2 , preamble  220  may include a legacy long training field (L-LTF)  224 , for example, based on the IEEE 802.11-2012 standard, e.g., according to section 18.3.3 (PLCP preamble), and/or in accordance with any other section and/or of any other Standard. 
     As shown in  FIG. 2 , preamble  220  may include a signal field (L-SIG)  226 , for example, based on the IEEE 802.11-2012 standard, e.g., according to section 18.3.4 (SIGNAL field), and/or in accordance with any other section and/or of any other Standard. 
     In some demonstrative embodiments, signal field  226  may include, for example, a rate field and/or a length field, for example, to indicate at least a duration of payload  230 . 
     In some demonstrative embodiments, message processor  128  ( FIG. 1 ) may be configured to set the rate field and the length field in signal field  226 , for example, based on a number of the plurality of OFDM tones, and a number of OOK bits in payload  230 . 
     In some demonstrative embodiments, the rate field and/or the length field may be set to values that indicate a longer time than an actual length of payload  230 , for example, to protect a response packet, which may follow wakeup packet  200 . 
     As shown in  FIG. 2 , payload  230  may include a wakeup preamble field  232 , a Media Access Control (MAC) header field  234 , a Frame body  236 , and/or a Frame Check Sequence (FCS) field  238 . In other embodiments, payload  230  may include any other additional or alternative fields. 
     Referring back to  FIG. 1 , in some demonstrative embodiments device  102  may be configured to generate a payload of a wakeup packet, e.g., payload  230  ( FIG. 2 ), for example, according to an OOK transmit pulse design, e.g., as described below. 
     In some demonstrative embodiments, controller  124  may cause, trigger and/or control radio  114  to generate an OOK transmit pulse over the plurality of OFDM tones. 
     In some demonstrative embodiments, the plurality of OFDM tones may include 12 OFDM tones. 
     In other embodiments, the plurality of OFDM tones may include any other number of OFDM tones, e.g., greater than or less than 12 OFDM tones. 
     In some demonstrative embodiments, message processor  128  may construct the OOK transmit pulse, for example, to provide improved performance of a wakeup radio link. 
     In some demonstrative embodiments, message processor  128  may construct the OOK transmit pulse using the plurality of OFDM tones, e.g., as described below. 
     In some demonstrative embodiments, a plurality of OFDM tones, including a number, denoted n, of a total number, denoted m, of OFDM tones, wherein n&lt;=m, may be used, for example, to construct the OOK transmit pulse, e.g., as described below with reference to  FIGS. 3 and/or 4 . 
     Reference is made to  FIG. 3 , which schematically illustrates a plurality of OFDM tones  320  of an OOK transmit pulse  300 , in accordance with some demonstrative embodiments. 
     In one example, controller  124  ( FIG. 1 ) may cause radio  114  ( FIG. 1 ) to generate the OOK transmit pulse  300  over the plurality of OFDM tones  320 . 
     As shown in  FIG. 3 , the plurality of OFDM tones  320  may include n tones, e.g., n=12, of a total number of m OFDM tones, e.g., m=64, for example, for a 20 Megahertz (MHz) channel According to this example, a wakeup signal bandwidth may be, for example, 4.06 MHz. 
     For example, as shown in  FIG. 3 , the plurality of OFDM tones  320  may include 12 tones centered on a central tone, e.g., a Direct Current (DC) tone, denoted “0”. For example, the plurality of OFDM tones  320  may include six tones, denoted “−6”, “−5”, “−4”, “−3”, “−2”, and “4”, on one side of the DC tone; and six tones, denoted “1”, “2”, “3”, “4”, “5”, and “6”, on another side of the DC tone. 
     In other embodiments, any other number of tones, and/or any other arrangement of tones may be used. 
     In some demonstrative embodiments, the OOK transmit pulse  300  may include, for example, the number n, e.g., n=12, of subcarriers, which may be modulated, for example, by elements of a predefined sequence, denoted S. 
     In some demonstrative embodiments, the sequence S may include, for example, the following sequence:
         S −26.26 =sqrt(13/6)*{0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 1+j, −1−j, 1+j, −1−j, −1−j, 1+j, 0, −1−j, −1−j, 1+j, 1+j, 1+j, 1+j, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0}       

     In other embodiments, any other sequence may be used. 
     In some demonstrative embodiments, controller  124  ( FIG. 1 ) may be configured to cause, control, and/or trigger radio  114  ( FIG. 1 ) to generate the OOK transmit pulse  300 , for example, using a transmit signal generation scheme of OFDM signals. 
     In one example, the OOK transmit pulse may be generated, for example, in compliance with the IEEE 802.11-2012 standard, e.g., followed by a 0.8 usec cyclic prefix extension. 
     Reference is made to  FIG. 4 , which schematically illustrates an OOK transmit pulse  400 , in accordance with some demonstrative embodiments. 
     In one example, controller  124  ( FIG. 1 ) may be configured to cause, control, and/or trigger radio  114  ( FIG. 1 ) to generate OOK transmit pulse  400 , for example, over the plurality of frequency tones  320  ( FIG. 3 ), e.g., as described above. 
     Referring back to  FIG. 1 , in some demonstrative embodiments, controller  124  may be configured to cause, control, and/or trigger radio  114  to modulate a plurality of payload values of the wakeup payload by selectively transmitting an OOK transmit pulse, e.g., OOK transmit pulse  400  ( FIG. 4 ), during one or more OFDM symbol periods of a plurality of OFDM symbol periods, e.g., as described below. 
     In some demonstrative embodiments, controller  124  may be configured to cause and/or trigger radio  114  to select whether or not to transmit the OOK transmit pulse over at least one OFDM symbol period, for example, based on a payload value. 
     In some demonstrative embodiments, controller  124  may be configured to cause and/or trigger radio  114  to select to transmit the OOK transmit pulse over the OFDM symbol period to indicate an on state of the OOK modulation scheme. For example, controller  124  may select to cause and/or trigger radio  114  to transmit the OOK transmit pulse over the OFDM symbol period, for example, if the payload value is “1”. 
     In one example, controller  124  may be configured to cause, control, and/or trigger radio  114  to transmit a first value, e.g., a value of ‘1’, in the payload field, for example, by transmitting the OOK transmit pulse, e.g., during one OFDM symbol period. 
     In some demonstrative embodiments, controller  124  may be configured to cause, control, and/or trigger radio  114  to select not to transmit the OOK transmit pulse over the OFDM symbol period to indicate an off state of the OOK modulation scheme. For example, controller  124  may select not to cause radio  114  to transmit the OOK transmit pulse over the OFDM symbol period, for example, if the payload value is “0”. 
     In one example, controller  124  may be configured to cause, control and/or trigger radio  114  to transmit a second value, e.g., a value of ‘0’, in the payload field, for example, by selecting not to transmit the OOK transmit pulse, e.g., during one OFDM symbol period. 
     In some demonstrative embodiments, a simple r repetition coding, e.g., an 1/r code rate, may be achieved, for example, by transmitting the OOK transmit pulses during r OFDM symbol periods, e.g., to transmit a value of ‘1’; and/or by not transmitting the OOK transmit pulse during r OFDM symbol periods, e.g., to transmit the value of ‘0’. 
     In some demonstrative embodiments, wakeup receiver  150  may receive the wakeup packet including the payload modulated according to the OOK scheme. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured to demodulate the plurality of payload values of the payload of the wakeup packet received from device  102 , for example, by detecting which OFDM symbol periods of the plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured to determine a first OOK value of a payload value corresponding to at least one OFDM symbol period, for example, when the OOK transmit pulse is received during the OFDM symbol period. For example, wakeup receiver  150  may determine an “on” state of the OOK modulation scheme, representing a first payload value, e.g., “1”, corresponding to at least one OFDM symbol period, for example, if the OOK transmit pulse is received during the OFDM symbol period. 
     In some demonstrative embodiments, wakeup receiver  150  may be configured to determine a second OOK value of a payload value corresponding to at least one OFDM symbol period, for example, when the OOK transmit pulse is not received during the OFDM symbol period. For example, wakeup receiver  150  may determine an “off” state of the OOK modulation scheme, representing a second payload value, e.g., “0”, corresponding to at least one OFDM symbol period, for example, if the OOK transmit pulse is not received during the OFDM symbol period. 
     In one example, wakeup receiver  150  may be configured to process the payload of the wakeup packet from device  102 , for example, by determining a value of ‘1’, e.g., with respect to a received OFDM symbol including the OOK transmit pulse; and/or determining a value of ‘0’, e.g., with respect to a received OFDM symbol not including the OOK transmit pulse. 
     Reference is made to  FIG. 5 , which schematically illustrates a transmission of a wakeup packet  500 , in accordance with some demonstrative embodiments. 
     In one example, device  102  ( FIG. 1 ) may transmit wakeup packet  500  to device  140  ( FIG. 1 ), for example, to indicate to wakeup receiver  150  ( FIG. 1 ) that radio  144  ( FIG. 1 ) is to be woken up. 
     As shown in  FIG. 5 , wakeup packet  500  may include a legacy preamble  502  followed by a payload  504 . 
     In some demonstrative embodiments, legacy preamble  502  may be modulated according to an OFDM modulation, e.g., as described above. 
     In some demonstrative embodiments, payload  504  may be modulated according to the OOK modulation scheme over a plurality of OFDM tones, e.g., as described above. 
     As shown in  FIG. 5 , payload  504  may include an OOK transmit pulse  506 , e.g., OOK transmit pulse  400  ( FIG. 4 ). 
     Referring back to  FIG. 1 , a design of an OOK transmit pulse, e.g., OOK transmit pulse  400  ( FIG. 4 ), of a wake up packet, e.g., wakeup packet  500  ( FIG. 5 ), may be configured, for example, to provide improved performance of a wakeup scheme. 
     In some demonstrative embodiments, designing a wakeup radio receiver, e.g., wakeup receiver  150 , for example, to meet extremely low power targets may lead to some performance losses, e.g., due to frequency offsets and/or interference. 
     In some demonstrative embodiments, the design of the OOK transmit pulse may be configured, for example, to reduce and/or mitigate the performance loss, for example, by using frequency domain information and/or hardware (HW) of an OFDM transmitter, e.g., transmitter  118 . 
     In some demonstrative embodiments, controller  154  may be configured to determine and/or adjust the subcarriers of the OOK transmit pulse, e.g., the plurality of OFDM tones  320  ( FIG. 3 ). 
     In some demonstrative embodiments, controller  154  may be configured to adjust and/or to adapt a number of the subcarriers, a location (index) of non-zero subcarriers, and/or a modulation on the subcarriers. 
     In some demonstrative embodiments, a sender of the wakeup transmit pulse, e.g., device  102 , and/or a receiver of the wakeup packet, e.g., device  140 , may be configured to perform interference and/or frequency offset measurements on the received wakeup signal, e.g., periodically, for example, as described below. 
     In some demonstrative embodiments, controller  154  may be configured to cause device  140  to transmit to device  102  feedback information configured to trigger an adjustment of the OOK modulation scheme over the plurality of OFDM tones. 
     In some demonstrative embodiments, the feedback information may include a frequency offset of the plurality of OFDM tones, and/or an interference to the plurality of OFDM tones, and/or information of one or more additional or alternative attributes. 
     In some demonstrative embodiments, transmitter  148  may transmit the feedback information to device  102 . 
     In one example, controller  159  may control, cause and/or trigger message generator  157  to generate a feedback message including the feedback information, and controller  159  and/or controller  154  may control, cause and/or trigger transmitter  148  to transmit the feedback message to device  102 . 
     In some demonstrative embodiments, device  102  may receive the feedback message. 
     In some demonstrative embodiments, controller  124  may be configured to select the plurality of OFDM tones to be used for modulating the wakeup packet, for example, based at least on the feedback information from device  140 . 
     In some demonstrative embodiments, controller  124  may be configured to adjust a modulation of the plurality of OFDM tones, e.g., based at least on the feedback from device  140 . 
     In one example, wakeup receiver  150  may feedback to radio  114 , e.g., via radio  144 , information indicating a frequency offset of the plurality of frequency tones  320  ( FIG. 3 ). For example, the frequency offset may be of +200 kHz. 
     According to this example, controller  124  may be configured to adapt the OOK transmit pulse in the frequency domain, for example, to compensate for the frequency offset of the plurality of frequency tones  320  ( FIG. 3 ), e.g., the frequency offset of +200 kHz. 
     For example, controller  124  may be configured to shift the plurality of frequency tones  320  ( FIG. 3 ) of the OOK transmit pulse  400  ( FIG. 4 ) by one index to the left, for example, if a subcarrier width is 312.5 kHz, e.g., according to an IEEE 802.11-2012 standard. Accordingly, a resulting down converted signal at wakeup receiver  150  may be closer to being centered at the Direct Current (DC), for example, to reduce a Signal to Noise Ratio (SNR) loss, e.g., due to filtering and the like. 
     In another example, controller  124  may be configured to modify the amplitudes of the plurality of frequency tones  320  ( FIG. 3 ) of the OOK transmit pulse  400  ( FIG. 4 ), for example, based at least on interference measurements fed back from wakeup receiver  150 . For example, controller  124  may be configured to modify the amplitudes of the plurality of frequency tones  320  ( FIG. 3 ), for example, to maximize an SNR at the output of a possible pulse matched filter, for example, at wakeup receiver  150 , e.g., to boost signal power at frequencies with lower interference. 
     In some demonstrative embodiments, adapting the design of the OOK transmit pulse in the frequency domain may be a valuable option, for example, at least for improving system performance. 
     In some demonstrative embodiments, using radio  114  to transmit the wakeup packet, for example, without using a dedicated OOK transmitter at device  102 , may enable implementation of a wakeup scheme in a flexible and/or easy manner. 
     Reference is made to  FIG. 6 , which schematically illustrates a method of communicating a wakeup packet, in accordance with some demonstrative embodiments. For example, one or more of the operations of the method of  FIG. 6  may be performed by one or more elements of a system, e.g., system  100  ( FIG. 1 ), for example, one or more wireless devices, e.g., device  102  ( FIG. 1 ), and/or device  140  ( FIG. 1 ), a controller, e.g., controller  159  ( FIG. 1 ), controller  124  ( FIG. 1 ) and/or controller  154  ( FIG. 1 ), a radio, e.g., radio  114  ( FIG. 1 ) and/or radio  144  ( FIG. 1 ), a transmitter, e.g., transmitter  118  and/or transmitter  148  ( FIG. 1 ); a receiver e.g., receiver  116 , receiver  156  and/or receiver  146  ( FIG. 1 ); a wakeup receiver, e.g., wakeup receiver  150  ( FIG. 1 ); and/or a message processor, e.g., message processor  157  ( FIG. 1 ), message processor  128  ( FIG. 1 ) and/or message processor  158  ( FIG. 1 ). 
     As indicated at block  602 , the method may include modulating at a first device a preamble of a wakeup packet according to an OFDM scheme. For example, device  102  ( FIG. 1 ) may modulate preamble  220  ( FIG. 2 ) of wakeup packet  220  ( FIG. 2 ) according to the OFDM scheme, e.g., as described above. 
     As indicated at block  604 , the method may include modulating a payload of the wakeup packet according to an OOK modulation scheme over a plurality of OFDM tones of the OFDM scheme. For example, device  102  ( FIG. 1 ) may modulate the payload  230  ( FIG. 2 ) of the wakeup packet  200  ( FIG. 2 ) according to the OOK modulation scheme over the plurality of OFDM tones of the OFDM scheme, e.g., as described above. 
     As indicated at block  606 , modulating the payload of the wakeup packet may include generating an OOK transmit pulse over the plurality of OFDM tones. For example, device  102  ( FIG. 1 ) may generate the OOK transmit pulse  400  ( FIG. 4 ) over the plurality of OFDM tones, e.g., as described above. 
     As indicated at block  608 , modulating the payload of the wakeup packet may include modulating a plurality of payload values of the payload by selectively transmitting the OOK transmit pulse during one or more OFDM symbol periods of a plurality of OFDM symbol periods. For example, device  102  ( FIG. 1 ) may modulate the payload  230  ( FIG. 2 ) by modulating the plurality of payload values of the payload by selectively transmitting the OOK transmit pulse  400  ( FIG. 4 ) during the one or more OFDM symbol periods of the plurality of OFDM symbol periods, e.g., as described above. 
     As indicated at block  610 , the method may include transmitting the wakeup packet to a second wireless device. For example, device  102  ( FIG. 1 ) may transmit the wakeup packet to device  140  ( FIG. 1 ), e.g., as described above. 
     As indicated at block  612 , the method may include demodulating, at a wakeup receiver of the second wireless device, a preamble of the wakeup packet from the first wireless device according to an OFDM scheme. For example, wakeup receiver  150  ( FIG. 1 ) may demodulate preamble  220  ( FIG. 2 ) of the wakeup packet from the first wireless device according to the OFDM scheme, e.g., as described above. 
     As indicated at block  614 , the method may include demodulating the payload of the wakeup packet according to OOK modulation scheme over the plurality of OFDM tones of the OFDM scheme. For example, wakeup receiver  150  ( FIG. 1 ) may demodulate the payload  230  ( FIG. 2 ) of the wakeup packet according to the OOK modulation scheme over the plurality of OFDM tones  320  ( FIG. 3 ), e.g., as described above. 
     As indicated at block  616 , demodulating the payload of the wakeup packet may include demodulating the plurality of payload values of the payload by detecting which OFDM symbol periods of the plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. For example, wakeup receiver  150  ( FIG. 1 ) may demodulate the payload of the wakeup packet by detecting which OFDM symbol periods of the plurality of OFDM symbol periods include OOK transmit pulse  400  ( FIG. 4 ), e.g., as described above. 
     As indicated at block  618 , the method may include activating a transceiver of the second wireless device based on the payload of the wakeup packet. For example, wakeup receiver  150  ( FIG. 1 ) may activate radio  144  ( FIG. 1 ), for example, based on the payload  230  ( FIG. 2 ) of the wakeup packet  200  ( FIG. 2 ), e.g., as described above. 
     Reference is made to  FIG. 7 , which schematically illustrates a product of manufacture  700 , in accordance with some demonstrative embodiments. Product  700  may include a non-transitory machine-readable storage medium  702  to store logic  704 , which may be used, for example, to perform at least part of the functionality of device  102  ( FIG. 1 ), device  140  ( FIG. 1 ), radio  114  ( FIG. 1 ), radio  144  ( FIG. 1 ), wakeup receiver  150  ( FIG. 1 ), transmitter  118  ( FIG. 1 ), transmitter  148  ( FIG. 1 ), receiver  116  ( FIG. 1 ), receiver  146  ( FIG. 1 ), controller  124  ( FIG. 1 ), controller  154  ( FIG. 1 ), message processor  128  ( FIG. 1 ), message processor  128  ( FIG. 1 ), and/or message processor  158  ( FIG. 1 ), and/or to perform one or more operations of the method of  FIG. 6 , and/or one or more operations described herein. The phrase “non-transitory machine-readable medium” is directed to include all computer-readable media, with the sole exception being a transitory propagating signal. 
     In some demonstrative embodiments, product  700  and/or machine-readable storage medium  702  may include one or more types of computer-readable storage media capable of storing data, including volatile memory, non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, and the like. For example, machine-readable storage medium  702  may include, RAM, DRAM, Double-Data-Rate DRAM (DDR-DRAM), SDRAM, static RAM (SRAM), ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), Compact Disk ROM (CD-ROM), Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), flash memory (e.g., NOR or NAND flash memory), content addressable memory (CAM), polymer memory, phase-change memory, ferroelectric memory, silicon-oxide-nitride-oxide-silicon (SONOS) memory, a disk, a floppy disk, a hard drive, an optical disk, a magnetic disk, a card, a magnetic card, an optical card, a tape, a cassette, and the like. The computer-readable storage media may include any suitable media involved with downloading or transferring a computer program from a remote computer to a requesting computer carried by data signals embodied in a carrier wave or other propagation medium through a communication link, e.g., a modem, radio or network connection. 
     In some demonstrative embodiments, logic  704  may include instructions, data, and/or code, which, if executed by a machine, may cause the machine to perform a method, process and/or operations as described herein. The machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, or the like, and may be implemented using any suitable combination of hardware, software, firmware, and the like. 
     In some demonstrative embodiments, logic  704  may include, or may be implemented as, software, a software module, an application, a program, a subroutine, instructions, an instruction set, computing code, words, values, symbols, and the like. 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 processor 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, such as C, C++, Java, BASIC, Matlab, Pascal, Visual BASIC, assembly language, machine code, and the like. 
     EXAMPLES 
     The following examples pertain to further embodiments. 
     Example 1 includes an apparatus comprising circuitry configured to cause a first wireless device to modulate a preamble of a wakeup packet according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; modulate a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and transmit the wakeup packet to a second wireless device. 
     Example 2 includes the subject matter of Example 1, and optionally, wherein the apparatus is configured to cause the first wireless device to generate an OOK transmit pulse over the plurality of OFDM tones, and to modulate a plurality of payload values of the payload by selectively transmitting the OOK transmit pulse during one or more OFDM symbol periods of a plurality of OFDM symbol periods. 
     Example 3 includes the subject matter of Example 2, and optionally, wherein the apparatus is configured to cause the first wireless device to select, based on a payload value, whether or not to transmit the OOK transmit pulse over at least one OFDM symbol period. 
     Example 4 includes the subject matter of Example 3, and optionally, wherein the apparatus is configured to cause the first wireless device to select to transmit the OOK transmit pulse over the OFDM symbol period to indicate an On-state of the OOK modulation scheme, and to select not to transmit the OOK transmit pulse over the OFDM symbol period to indicate an Off-state of the OOK modulation scheme. 
     Example 5 includes the subject matter of any one of Examples 1-4, and optionally, wherein the apparatus is configured to cause the first wireless device to select the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 6 includes the subject matter of any one of Examples 1-5, and optionally, wherein the apparatus is configured to cause the first wireless device to adjust a modulation of the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 7 includes the subject matter of any one of Examples 1-6, and optionally, wherein the apparatus is configured to cause the first wireless device to set a signal field in the preamble to indicate at least a duration of the payload. 
     Example 8 includes the subject matter of Example 7, and optionally, wherein the apparatus is configured to cause the first wireless device to set a rate field and a length field in the signal field based on a number of the plurality of OFDM tones, and a number of OOK bits in the payload. 
     Example 9 includes the subject matter of any one of Examples 1-8, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 10 includes the subject matter of any one of Examples 1-9, and optionally, comprising a transmitter configured to transmit the wakeup packet. 
     Example 11 includes the subject matter of any one of Examples 1-10, and optionally, comprising one or more antennas, and a memory. 
     Example 12 includes a system of wireless communication comprising a first wireless device, the first wireless device comprising one or more antennas; a memory; a processor; and a radio configured to modulate a preamble of a wakeup packet according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme, to modulate a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme, and to transmit the wakeup packet to a second wireless device. 
     Example 13 includes the subject matter of Example 12, and optionally, wherein the first wireless device is to generate an OOK transmit pulse over the plurality of OFDM tones, and to modulate a plurality of payload values of the payload by selectively transmitting the OOK transmit pulse during one or more OFDM symbol periods of a plurality of OFDM symbol periods. 
     Example 14 includes the subject matter of Example 13, and optionally, wherein the first wireless device is to select, based on a payload value, whether or not to transmit the OOK transmit pulse over at least one OFDM symbol period. 
     Example 15 includes the subject matter of Example 14, and optionally, wherein the first wireless device is to select to transmit the OOK transmit pulse over the OFDM symbol period to indicate an On-state of the OOK modulation scheme, and to select not to transmit the OOK transmit pulse over the OFDM symbol period to indicate an Off-state of the OOK modulation scheme. 
     Example 16 includes the subject matter of any one of Examples 12-15, and optionally, wherein the first wireless device is to select the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 17 includes the subject matter of any one of Examples 12-16, and optionally, wherein the first wireless device is to adjust a modulation of the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 18 includes the subject matter of any one of Examples 12-17, and optionally, wherein the first wireless device is to set a signal field in the preamble to indicate at least a duration of the payload. 
     Example 19 includes the subject matter of Example 18, and optionally, wherein the first wireless device is to set a rate field and a length field in the signal field based on a number of the plurality of OFDM tones, and a number of OOK bits in the payload. 
     Example 20 includes the subject matter of any one of Examples 12-19, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 21 includes a method to be performed by a first wireless device, the method comprising modulating a preamble of a wakeup packet according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; modulating a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and transmitting the wakeup packet to a second wireless device. 
     Example 22 includes the subject matter of Example 21, and optionally, comprising generating an OOK transmit pulse over the plurality of OFDM tones, and modulating a plurality of payload values of the payload by selectively transmitting the OOK transmit pulse during one or more OFDM symbol periods of a plurality of OFDM symbol periods. 
     Example 23 includes the subject matter of Example 22, and optionally, comprising selecting, based on a payload value, whether or not to transmit the OOK transmit pulse over at least one OFDM symbol period. 
     Example 24 includes the subject matter of Example 23, and optionally, comprising selecting to transmit the OOK transmit pulse over the OFDM symbol period to indicate an On-state of the OOK modulation scheme, and selecting not to transmit the OOK transmit pulse over the OFDM symbol period to indicate an Off-state of the OOK modulation scheme. 
     Example 25 includes the subject matter of any one of Examples 21-24, and optionally, comprising selecting the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 26 includes the subject matter of any one of Examples 21-25, and optionally, comprising adjusting a modulation of the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 27 includes the subject matter of any one of Examples 21-26, and optionally, comprising setting a signal field in the preamble to indicate at least a duration of the payload. 
     Example 28 includes the subject matter of Example 27, and optionally, comprising setting a rate field and a length field in the signal field based on a number of the plurality of OFDM tones, and a number of OOK bits in the payload. 
     Example 29 includes the subject matter of any one of Examples 21-28, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 30 includes a product comprising one or more tangible computer-readable non-transitory storage media comprising computer-executable instructions operable to, when executed by at least one computer processor, enable the at least one computer processor to implement one or more operations at a first wireless device, the operations comprising modulating a preamble of a wakeup packet according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; modulating a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and transmitting the wakeup packet to a second wireless device. 
     Example 31 includes the subject matter of Example 30, and optionally, wherein the operations comprise generating an OOK transmit pulse over the plurality of OFDM tones, and modulating a plurality of payload values of the payload by selectively transmitting the OOK transmit pulse during one or more OFDM symbol periods of a plurality of OFDM symbol periods. 
     Example 32 includes the subject matter of Example 31, and optionally, wherein the operations comprise selecting, based on a payload value, whether or not to transmit the OOK transmit pulse over at least one OFDM symbol period. 
     Example 33 includes the subject matter of Example 32, and optionally, wherein the operations comprise selecting to transmit the OOK transmit pulse over the OFDM symbol period to indicate an On-state of the OOK modulation scheme, and selecting not to transmit the OOK transmit pulse over the OFDM symbol period to indicate an Off-state of the OOK modulation scheme. 
     Example 34 includes the subject matter of any one of Examples 30-33, and optionally, wherein the operations comprise selecting the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 35 includes the subject matter of any one of Examples 30-34, and optionally, wherein the operations comprise adjusting a modulation of the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 36 includes the subject matter of any one of Examples 30-35, and optionally, wherein the operations comprise setting a signal field in the preamble to indicate at least a duration of the payload. 
     Example 37 includes the subject matter of Example 36, and optionally, wherein the operations comprise setting a rate field and a length field in the signal field based on a number of the plurality of OFDM tones, and a number of OOK bits in the payload. 
     Example 38 includes the subject matter of any one of Examples 30-37, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 39 includes an apparatus of wireless communication by a first wireless device, the apparatus comprising means for modulating at the first wireless device a preamble of a wakeup packet according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; means for modulating a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and means for transmitting the wakeup packet to a second wireless device. 
     Example 40 includes the subject matter of Example 39, and optionally, comprising means for generating an OOK transmit pulse over the plurality of OFDM tones, and means for modulating a plurality of payload values of the payload by selectively transmitting the OOK transmit pulse during one or more OFDM symbol periods of a plurality of OFDM symbol periods. 
     Example 41 includes the subject matter of Example 40, and optionally, comprising means for selecting, based on a payload value, whether or not to transmit the OOK transmit pulse over at least one OFDM symbol period. 
     Example 42 includes the subject matter of Example 41, and optionally, comprising means for selecting to transmit the OOK transmit pulse over the OFDM symbol period to indicate an On-state of the OOK modulation scheme, and selecting not to transmit the OOK transmit pulse over the OFDM symbol period to indicate an Off-state of the OOK modulation scheme. 
     Example 43 includes the subject matter of any one of Examples 39-42, and optionally, comprising means for selecting the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 44 includes the subject matter of any one of Examples 39-43, and optionally, comprising means for adjusting a modulation of the plurality of OFDM tones based on a feedback from the second wireless device. 
     Example 45 includes the subject matter of any one of Examples 39-44, and optionally, comprising means for setting a signal field in the preamble to indicate at least a duration of the payload. 
     Example 46 includes the subject matter of Example 45, and optionally, comprising means for setting a rate field and a length field in the signal field based on a number of the plurality of OFDM tones, and a number of OOK bits in the payload. 
     Example 47 includes the subject matter of any one of Examples 39-46, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 48 includes an apparatus comprising circuitry configured to cause a first wireless device to demodulate, at a wakeup receiver of the first wireless device, a preamble of a wakeup packet from a second wireless device according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; demodulate, at the wakeup receiver of the first wireless device, a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and based on the payload of the wakeup packet, activate a transceiver of the first wireless device. 
     Example 49 includes the subject matter of Example 48, and optionally, wherein the apparatus is configured to cause the first wireless device to demodulate a plurality of payload values of the payload by detecting which OFDM symbol periods of a plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. 
     Example 50 includes the subject matter of Example 49, and optionally, wherein the apparatus is configured to cause the first wireless device to determine an On-state of the OOK modulation scheme of a payload value corresponding to at least one OFDM symbol period when the OOK transmit pulse is received during the OFDM symbol period, and to determine an Off-state of the OOK modulation scheme of the payload value corresponding to the OFDM symbol period when the OOK transmit pulse is not received during the OFDM symbol period. 
     Example 51 includes the subject matter of any one of Examples 48-50, and optionally, wherein the apparatus is configured to cause the first wireless device to transmit to the second wireless device feedback information configured to trigger an adjustment of the OOK modulation scheme over the plurality of OFDM tones. 
     Example 52 includes the subject matter of Example 51, and optionally, wherein the feedback information comprises at least one attribute selected from the group consisting of a frequency offset of the plurality of OFDM tones, and an interference to the plurality of OFDM tones. 
     Example 53 includes the subject matter of any one of Examples 48-52, and optionally, wherein the apparatus is configured to cause the first wireless device to determine a length of the payload based on a signal field in the preamble. 
     Example 54 includes the subject matter of any one of Examples 48-53, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 55 includes the subject matter of any one of Examples 48-54, and optionally, comprising the wakeup receiver and the transceiver. 
     Example 56 includes the subject matter of any one of Examples 48-55, and optionally, comprising one or more antennas, and a memory. 
     Example 57 includes a system of wireless communication comprising a first wireless device, the first wireless device comprising one or more antennas; a memory; a processor; a transceiver; and a wakeup receiver configured to demodulate a preamble of a wakeup packet from a second wireless device according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme, to demodulate a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme, and based on the payload of the wakeup packet, to activate the transceiver to communicate with the second wireless device. 
     Example 58 includes the subject matter of Example 57, and optionally, wherein the first wireless device is to demodulate a plurality of payload values of the payload by detecting which OFDM symbol periods of a plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. 
     Example 59 includes the subject matter of Example 58, and optionally, wherein the first wireless device is to determine an On-state of the OOK modulation scheme of a payload value corresponding to at least one OFDM symbol period when the OOK transmit pulse is received during the OFDM symbol period, and to determine an Off-state of the OOK modulation scheme of the payload value corresponding to the OFDM symbol period when the OOK transmit pulse is not received during the OFDM symbol period. 
     Example 60 includes the subject matter of any one of Examples 57-59, and optionally, wherein the first wireless device is to transmit to the second wireless device feedback information configured to trigger an adjustment of the OOK modulation scheme over the plurality of OFDM tones. 
     Example 61 includes the subject matter of Example 60, and optionally, wherein the feedback information comprises at least one attribute selected from the group consisting of a frequency offset of the plurality of OFDM tones, and an interference to the plurality of OFDM tones. 
     Example 62 includes the subject matter of any one of Examples 57-61, and optionally, wherein the first wireless device is to determine a length of the payload based on a signal field in the preamble. 
     Example 63 includes the subject matter of any one of Examples 57-62, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 64 includes a method to be performed by a first wireless device, the method comprising demodulating, at a wakeup receiver of the first wireless device, a preamble of a wakeup packet from a second wireless device according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; demodulating, at the wakeup receiver of the first wireless device, a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and based on the payload of the wakeup packet, activating a transceiver of the first wireless device. 
     Example 65 includes the subject matter of Example 64, and optionally, comprising demodulating a plurality of payload values of the payload by detecting which OFDM symbol periods of a plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. 
     Example 66 includes the subject matter of Example 65, and optionally, comprising determining an On-state of the OOK modulation scheme of a payload value corresponding to at least one OFDM symbol period when the OOK transmit pulse is received during the OFDM symbol period, and determining an Off-state of the OOK modulation scheme of the payload value corresponding to the OFDM symbol period when the OOK transmit pulse is not received during the OFDM symbol period. 
     Example 67 includes the subject matter of any one of Examples 64-66, and optionally, comprising transmitting to the second wireless device feedback information configured to trigger an adjustment of the OOK modulation scheme over the plurality of OFDM tones. 
     Example 68 includes the subject matter of Example 67, and optionally, wherein the feedback information comprises at least one attribute selected from the group consisting of a frequency offset of the plurality of OFDM tones, and an interference to the plurality of OFDM tones. 
     Example 69 includes the subject matter of any one of Examples 64-68, and optionally, comprising determining a length of the payload based on a signal field in the preamble. 
     Example 70 includes the subject matter of any one of Examples 64-69, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 71 includes a product comprising one or more tangible computer-readable non-transitory storage media comprising computer-executable instructions operable to, when executed by at least one computer processor, enable the at least one computer processor to implement one or more operations at a first wireless device, the operations comprising demodulating, at a wakeup receiver of the first wireless device, a preamble of a wakeup packet from second wireless device according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; demodulating, at the wakeup receiver of the first wireless device, a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and based on the payload of the wakeup packet, activating a transceiver of the first wireless device. 
     Example 72 includes the subject matter of Example 71, and optionally, wherein the operations comprise demodulating a plurality of payload values of the payload by detecting which OFDM symbol periods of a plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. 
     Example 73 includes the subject matter of Example 72, and optionally, wherein the operations comprise determining an On-state of the OOK modulation scheme of a payload value corresponding to at least one OFDM symbol period when the OOK transmit pulse is received during the OFDM symbol period, and determining an Off-state of the OOK modulation scheme of the payload value corresponding to the OFDM symbol period when the OOK transmit pulse is not received during the OFDM symbol period. 
     Example 74 includes the subject matter of any one of Examples 71-73, and optionally, wherein the operations comprise transmitting to the second wireless device feedback information configured to trigger an adjustment of the OOK modulation scheme over the plurality of OFDM tones. 
     Example 75 includes the subject matter of Example 74, and optionally, wherein the feedback information comprises at least one attribute selected from the group consisting of a frequency offset of the plurality of OFDM tones, and an interference to the plurality of OFDM tones. 
     Example 76 includes the subject matter of any one of Examples 71-75, and optionally, wherein the operations comprise determining a length of the payload based on a signal field in the preamble. 
     Example 77 includes the subject matter of any one of Examples 71-76, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Example 78 includes an apparatus of wireless communication by a first wireless device, the apparatus comprising means for demodulating, at a wakeup receiver of the first wireless device, a preamble of a wakeup packet from second wireless device according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme; means for demodulating, at the wakeup receiver of the first wireless device, a payload of the wakeup packet according to an On-Off keying (OOK) modulation scheme over a plurality of OFDM tones of the OFDM scheme; and means for, based on the payload of the wakeup packet, activating a transceiver of the first wireless device. 
     Example 79 includes the subject matter of Example 78, and optionally, comprising means for demodulating a plurality of payload values of the payload by detecting which OFDM symbol periods of a plurality of OFDM symbol periods include an OOK transmit pulse over the plurality of OFDM tones. 
     Example 80 includes the subject matter of Example 79, and optionally, comprising means for determining an On-state of the OOK modulation scheme of a payload value corresponding to at least one OFDM symbol period when the OOK transmit pulse is received during the OFDM symbol period, and determining an Off-state of the OOK modulation scheme of the payload value corresponding to the OFDM symbol period when the OOK transmit pulse is not received during the OFDM symbol period. 
     Example 81 includes the subject matter of any one of Examples 78-80, and optionally, comprising means for transmitting to the second wireless device feedback information configured to trigger an adjustment of the OOK modulation scheme over the plurality of OFDM tones. 
     Example 82 includes the subject matter of Example 81, and optionally, wherein the feedback information comprises at least one attribute selected from the group consisting of a frequency offset of the plurality of OFDM tones, and an interference to the plurality of OFDM tones. 
     Example 83 includes the subject matter of any one of Examples 78-82, and optionally, comprising means for determining a length of the payload based on a signal field in the preamble. 
     Example 84 includes the subject matter of any one of Examples 78-83, and optionally, wherein the plurality of OFDM tones comprises 12 OFDM tones. 
     Functions, operations, components and/or features described herein with reference to one or more embodiments, may be combined with, or may be utilized in combination with, one or more other functions, operations, components and/or features described herein with reference to one or more other embodiments, or vice versa. 
     While certain features have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.