Communication system and method with recovery detection

Abstract

The invention relates to a communication system and method with recovery detection. A wireless device may include a first radio configured to transmit to a first device over a first link and a second link of a first wireless frequency band. The first device includes circuitry configured to provide data to a second device across a connection including one or more links. The circuitry is configured to detect the presence of at least a portion of a packet using a relationship of guard tones to signal tones in a bandwidth. The wireless device may be capable of recovering from blind with less latency.

Description

Technical Field

[0001] This disclosure generally relates to systems and methods for communication between a station (STA) and an access point (AP) (e.g., in a wireless local area network) or other communication devices. Background Technology

[0002] Over the past few decades, the market for wireless communication devices has grown by orders of magnitude, driven by the use of portable devices and increased connectivity and data transmission between a wide variety of devices. Digital switching technology has facilitated the large-scale deployment of affordable and easy-to-use wireless communication networks. Furthermore, improvements in digital and radio frequency (RF) circuit manufacturing, as well as advancements in circuit integration and other areas, have made wireless equipment smaller, cheaper, and more reliable. Wireless communication can operate according to various standards, such as IEEE 802.11x, Bluetooth, Global System for Mobile Communications (GSM), and Code Division Multiple Access (CDMA). As data processing capabilities, network density, and other changes evolve, newer standards are constantly being developed for adoption, such as the progression from IEEE 802.11n to IEEE 802.11ac, ax, or be. Network devices can operate as client stations (STAs), access points (APs), or mobile APs. IEEE 802.11be defines EMLSR (Enhanced Multilink Single Radio) for non-AP STAs. Interference and traffic conflicts can hinder network performance. Summary of the Invention

[0003] In one aspect, this disclosure provides a first device comprising: an antenna; and circuitry configured to provide data to a second device via the antenna across a connection including one or more links, wherein the circuitry is configured to detect the presence of at least a portion of a packet using a relationship between a guard tone and a signal tone in the bandwidth, and to synchronize to a channel if the packet is not present.

[0004] In another aspect, this disclosure provides a first device comprising: an antenna; and circuitry configured to provide packets to a second device via the antenna across a connection including one or more links, wherein the circuitry includes a spectrum module configured to provide spectral data indicating energy in a bandwidth and a detector configured to use the spectral data to detect the presence of at least a portion of the packets in response to an energy relationship between a guard tone and a signal tone in the bandwidth.

[0005] In another aspect, this disclosure provides a method for blind recovery from a communication system, the method comprising: using an antenna to provide spectral data indicating energy for a bandwidth; using the spectral data to determine a first relationship between a set of signal tones in the bandwidth that is higher than a first threshold; and using the spectral data to determine a second relationship between the energy of a guard tone and a signal tone in the bandwidth; and detecting the presence of at least a portion of a packet in response to the first relationship and the second relationship. Attached Figure Description

[0006] The various objects, aspects, features, and advantages of this disclosure will become more apparent and better understood through a detailed description taken in conjunction with the accompanying drawings, in which similar reference numerals identify corresponding elements throughout. In the drawings, the same reference numerals generally indicate the same, functionally similar, and / or structurally similar elements.

[0007] Figure 1A It is a block diagram depicting a network environment comprising one or more access points communicating with one or more devices or stations, according to some embodiments.

[0008] Figure 1B and 1C This is a block diagram depicting a computing device used in conjunction with the methods and systems described herein, according to some embodiments.

[0009] Figure 2 This describes a wireless network according to some embodiments.

[0010] Figure 3A According to some embodiments Figure 2 The diagram illustrates a general block diagram of an AP or STA in a network.

[0011] Figure 3B This is to illustrate according to some embodiments Figure 2 The waveform diagram of the signal in the bandwidth of the network is described in the figure.

[0012] Figure 4 This is a flowchart illustrating communication in the network shown in Figure 3 using a group detection scheme according to some embodiments.

[0013] Figure 5 This is a flowchart illustrating communication in the network shown in Figure 3 using a packet detection scheme with multiple bandwidths according to some embodiments.

[0014] Figure 6 It is a graph showing the probability of grouping according to some embodiments.

[0015] Figure 7 It is a graph showing the probability of false alarms in grouping according to some embodiments.

[0016] Details of various embodiments of the method and system are set forth in the accompanying drawings and the description below. Detailed Implementation

[0017] The following IEEE standards (including any draft versions of such standards) are hereby incorporated herein by reference in their entirety and constitute a part of this disclosure for all purposes: WiFi Alliance standards and IEEE 802.11 standards, including but not limited to IEEE 802.11a™, IEEE 802.11b™, IEEE 802.11be™, IEEE 802.11bn™, IEEE 802.11g™, IEEE P802.11n™, and IEEE P802.11ac™ standards. Although this disclosure may reference certain aspects of these standards, it is in no way limited to these standards.

[0018] The following description of sections and corresponding contents of this specification may be helpful in reading the descriptions of the various embodiments described below:

[0019] Section A describes the network and computing environments that can be used to practice the embodiments described herein; and

[0020] Section B describes embodiments of group detection and blind recovery protocols, as well as methods and apparatus for using such protocols.

[0021] In some embodiments, the system and method rapidly synchronize with the communication medium, thereby allowing for faster media access and avoiding any air collisions. In some embodiments, significant performance gains can be achieved in wireless implementations. The system and method can be used with WiFi technology and non-Wi-Fi technologies such as LTE-U, LAA, etc. In some embodiments, synchronization can refer to the process of ensuring that transmitted signals are correctly aligned in terms of time and / or frequency. In some embodiments, proper synchronization allows the device to coordinate the transmission and reception of frames to avoid collisions and ensures efficient use of the wireless medium and / or promotes energy-saving mechanisms, thereby allowing the device to sleep and wake up at appropriate times without missing communication opportunities. In some embodiments, synchronization in various modes can be performed according to IEEE standards.

[0022] Various client devices can operate as single-link and multi-link station (STA) devices using one or more radios (e.g., multi-link single radio (MLSR)). For example, client devices can use MLSR radios for each of various frequency bands (e.g., 2.4 GHz, 5 GHz, or 6 GHz). Various STA devices can operate as APs or non-APs. Non-AP devices are typically clients of AP devices. In some cases, non-AP devices can be configured as mobile APs or portable hotspots, in which case they can support other non-AP devices as their clients. APs / mobile APs and their clients can communicate using multi-link operation using one or more radios on multiple links. APs and clients can be used in any communication environment, including but not limited to WLAN, LTE, LTE-U, LAA, 5G, 6G, etc.

[0023] In some embodiments, Enhanced Multi-Link Single Radio (EMLSR) operation may involve a STA associated with a multi-link AP (e.g., an AP operating simultaneously on two or more different links / channels). The STA can be configured to dynamically switch between links on a per TXOP (transmission opportunity) basis while communicating with the AP. Many technologies incorporating WLAN deploy Carrier Sense Multiple Access with Collision Avoidance (CSMA-CA) as a network protocol to manage how data packets are transmitted over a shared communication medium (e.g., one or more wireless links) in a wireless local area network (WLAN). CSMA-CA uses carrier sensing to check whether a wireless channel is idle or in use. If the channel is found to be idle (no traffic), the device waits for a random backoff time before transmitting its data. This backoff time helps avoid collisions that can occur when multiple devices simultaneously sense an idle channel and attempt to transmit simultaneously.

[0024] If the channel is busy, the device continues listening until it becomes idle, waits for the backoff period, and attempts to transmit. After successfully transmitting data, the sender expects an acknowledgment (ACK) from the receiver. If an ACK is received, the received ACK indicates a successful transmission. If no ACK is received (indicating a possible collision), the sender assumes the transmission failed and tries again after another backoff period.

[0025] If a device lacks the ability to listen to the carrier at a specific time (e.g., for CSMA-CA) or does not perform sensing operations, then the device is considered blind or has entered a blind state. When a device is blind, it may lose or be unable to receive the preamble of incoming packets, thereby losing synchronization with the medium. The preamble may be lost due to collisions or other interference.

[0026] When a device synchronizes with the media before accessing it, it can more easily avoid air collisions and thereby improve network throughput. Current mechanisms for achieving this synchronization are suboptimal due to very high latency and limited coverage of Received Signal Strength Indicator (RSSI) zones. RSSI is a measurement of the power level received by a wireless device from a signal transmitted over a wireless network (such as Wi-Fi, Bluetooth, or a cellular network). RSSI is used to determine the quality and strength of a wireless connection. In some embodiments, RSSI values ​​refer to RSSI data expressed digitally.

[0027] In some embodiments, the system and method provide faster recovery from temporary blinds. In some embodiments, an orthogonal frequency division multiplexing (OFDM) detector is used to detect idle communication links with very low latency and small RSSI area coverage. In some embodiments, a robust detector is configured to detect the presence of very low over-the-air RSSI OFDM packets immediately after a blind. In some embodiments, the system and method achieve several orders of magnitude improvement in latency, thereby enabling fast synchronization and better network efficiency.

[0028] In some embodiments, an OFDM detector is configured to detect the presence of WLAN OFDM packets even if the WLAN OFDM packets have low signal strength. In some embodiments, OFDM packets are detected even if the preamble is missed due to blindness. In some embodiments, the system and method perform spectral analysis of the incoming signal and compare the incoming components with the expected spectrum of any OFDM WLAN packet. In some embodiments, the detector receives the bandwidth of the signal and compares the energy on the loaded and unloaded tones with the expected guard tone of any WLAN packet to detect packet presence. In some embodiments, this comparison allows differentiation of any WLAN OFDM packet from other airborne signals without any timing or frequency synchronization. The presence of spectrum usage can be detected by any technology or circuitry system. In some embodiments, the guard tone is not used to detect packets, and other spectral components (e.g., pilot tones) are utilized. In some embodiments, the system and method detect airborne OFDM and includes a cyclic prefix (CP) detector, and analyzes the autocorrelation of the time-domain signal across different hysteresis to determine the OFDM symbol length and thereby determine the presence of an airborne OFDM signal.

[0029] In some embodiments, a blind refers to a scenario in which a network node or device is unable to detect or respond to certain signals, data, or conditions within the network. In some embodiments, a temporary blind refers to a non-permanent blind. Blinds can occur for various reasons, including but not limited to interference, signal attenuation, or limitations in the design of network protocols, features, or hardware. For example, a blind can occur with respect to auxiliary packets having an RSSI of less than -72 dBm in a 20 MHz bandwidth (BW). In lower BW transmissions, if the device transmits on other sub-bands during the said time period, the preamble of the auxiliary sub-band packets may be lost. For example, the feature of dynamically transmitted BWs can cause blinds associated with packets using this feature. Performing only primary sensing can also cause blinds. For example, features such as EMLSR and power-saving options can limit the ability to sense outside the primary channel 20 MHz BW. Sensing only the 20 MHz primary BW can also cause blinds. Loss of the preamble on the auxiliary channel during PCF inter-frame spacing (PIFS) sensing can also cause blinds. Blinding can be associated with different auxiliary packets on different sub-bands because, in some cases, a single physical layer (PHY) detector / decoder only identifies one auxiliary packet. Furthermore, blinding can be caused by time-overlapping auxiliary packets, as the sources of such packets are hidden from each other. Blinding can also occur on the primary sub-band. For example, in EMLSR operation, media synchronization recovery as defined in the IEEE standard only resolves blinding issues for packets with an RSSI greater than -72 dBm. In watchdog operation, monitoring activity and block reconfiguration cause deafness in the system. During this time, synchronization with the media is lost. Blinding also occurs when time-overlapping packets, as packet sources, are hidden from each other on the primary sub-band. In operations related to power-saving sleep modes, coexistence with other technologies, etc., waking up after such events has the same operational problems as waking up after blinding. The systems and methods described above can be used to achieve faster synchronization after waking up.

[0030] A mobile AP can be a non-simultaneous transmit-receive (NSTR) device on a pair of links as defined in the 802.11 standard. Additionally, an AP or mobile AP can be an EMLSR device on a pair of links. An EMLSR AP / mobile AP uses EMLSR operation to communicate with its clients over multiple links. In some embodiments, multiple EMLSR APs can advantageously coordinate their link switches. Two such client devices can communicate via one or more non-simultaneous transmit and receive (NSTR) links. For example, two clients can operate between 2.4 GHz, 5 GHz, and 6 GHz links. The network may include arbitration mechanisms or other methods to determine transmit opportunities (TXOPs) within a subnet, such as a basic service set (BSS) of devices containing client devices (e.g., STAs) that can communicate via an access point (e.g., an AP or mobile AP).

[0031] In some embodiments, the AP and / or client support packet detection and recovery following the blind protocol described herein. The protocol is implemented in 802.11 APs and non-AP STA chips or integrated circuits housed in a package.

[0032] Some embodiments relate to a first device. The first device includes circuitry configured to provide data to a second device across a connection including one or more links. The circuitry is configured to detect the presence of at least a portion of a packet using the relationship between a guard tone and a signal tone in the bandwidth.

[0033] A connection refers to any communication link established between two devices. In some embodiments, a connection may be established after discovery, authentication, and association. In some embodiments, a device refers to any type of electronic device used for communication. In some embodiments, bandwidth refers to a portion of the electromagnetic spectrum. In some embodiments, bandwidth may be a sub-band, a channel or a portion thereof, or a link or a portion thereof. A relationship may refer to correlation, connection, or other association. For example, a relationship may involve comparison, mathematical operations, or logical operations. In some embodiments, a relationship may be greater than, equal to, or less than a relationship or involve subtraction, addition, multiplication, division, etc.

[0034] In some embodiments, the bandwidth is 20 MHz. In some embodiments, the circuitry is configured to detect presence using a relationship between the signal tone and a first threshold. In some embodiments, the first threshold is a fixed threshold. In some embodiments, the circuitry is configured to detect presence by comparing a relationship between the guard tone in the bandwidth and the signal tone and a second threshold. In some embodiments, the packet is an orthogonal frequency domain multiplexed packet. In some embodiments, the packet is a wideband packet. In some embodiments, the circuitry is part of an access point or station. In some embodiments, the comparison refers to the determination of a relationship, such as a greater than, equal to, or less than relationship, or a combination thereof.

[0035] Some embodiments relate to a first device including circuitry configured to provide packets to a second device across a connection comprising one or more links. The circuitry includes a spectrum module configured to provide spectral data indicating energy in a bandwidth and a detector configured to use the spectral data to detect the presence of at least a portion of the packets in response to an energy relationship between a guard tone and a signal tone in the bandwidth. In some embodiments, a detector refers to circuitry or software used for detecting conditions. In some embodiments, detecting refers to an action or operation that discovers or identifies a condition or characteristic. In some embodiments, a spectrum module or software refers to circuitry or software used to obtain spectral data conditions. In some embodiments, spectral data refers to data representing energy at a specific frequency.

[0036] In some embodiments, the circuitry is used for recovery from a blind state. In some embodiments, the circuitry is configured to detect packets without detecting a preamble. In some embodiments, the spectral data includes Received Signal Strength Indicator (RSSI) values. In some embodiments, the detector is configured to detect presence using the relationship between a guard tone and a signal tone in the bandwidth. In some embodiments, the detector is configured to detect presence using a set of relationships between signal tones and a first threshold. In some embodiments, the relationship between the guard tone and the signal tone is compared to a threshold. In some embodiments, the threshold is 8 dB.

[0037] Some embodiments relate to a method for blind recovery from a communication system. The method includes: providing spectral data indicating energy for a bandwidth; using the spectral data to determine that a first relationship between a set of signal tones in the bandwidth is higher than a first threshold; using the spectral data to determine a second relationship between the energy of a guard tone and the signal tones in the bandwidth; and detecting the presence of at least a portion of a packet in response to the first and second relationships.

[0038] In some embodiments, the second relationship is the difference between the energy of the guard tone and the signal tone. In some embodiments, the first relationship is a comparison of the signal tone with a threshold. In some embodiments, the threshold is a noise threshold. In some embodiments, the noise threshold refers to the energy level associated with noise in the bandwidth. The energy associated with the noise threshold can be associated with various sources. The noise threshold level depends on the environment, protocol, device capabilities, mitigation techniques, etc.

[0039] A. Computing and Network Environment

[0040] Before discussing specific embodiments of the solutions of the present invention, it may be helpful to describe the operating environment and associated system components (e.g., hardware elements) in conjunction with the methods and systems described herein. References Figure 1A This describes an embodiment of a network environment. In brief, the network environment includes a wireless communication system comprising one or more access points (APs) or network devices 106, one or more stations or wireless communication devices 102, and network hardware components or network hardware 192. Wireless communication device 102 may, for example, include a laptop computer, tablet computer, personal computer, and / or cellular phone device. Reference Figure 1B and 1CMore detailed descriptions are provided for embodiments of each station or wireless communication device 102 and AP or network device 106. In one embodiment, the network environment may be an ad hoc network environment, an infrastructure wireless network environment, a subnet environment, etc. Network device 106 or AP may be operatively coupled to network hardware 192 via a local area network (LAN) connection. In some embodiments, network device 106 is a 5G base station. Network hardware 192, which may include routers, gateways, switches, bridges, modems, system controllers, appliances, etc., may provide LAN connectivity for the communication system. Each of network device 106 or AP may have an associated antenna or antenna array for communicating with wireless communication devices in its area. Wireless communication device 102 may register with a specific network device 106 or AP to receive services from the communication system (e.g., via SU-MIMO or MU-MIMO configuration). For direct connections (e.g., point-to-point communication), some wireless communication devices may communicate directly via assigned channels and communication protocols. Some of wireless communication devices 102 may be mobile or relatively static relative to network device 106 or AP.

[0041] In some embodiments, network device 106 or AP includes means or modules (comprising a combination of hardware and software) that allow wireless communication device 102 to connect to a wired network using Wi-Fi or other standards. Network device 106 or AP may sometimes be referred to as a wireless access point (WAP). Network device 106 or AP can be implemented (e.g., configured, designed, and / or built) for operation in a wireless local area network (WLAN). In some embodiments, network device 106 or AP can be connected as a standalone device to a router (e.g., via a wired network). In other embodiments, network device 106 or AP can be a component of a router. Network device 106 or AP can provide network access to multiple devices. Network device 106 or AP can, for example, connect to a wired Ethernet connection and use a radio frequency link to provide wireless connectivity for other devices 102 to utilize that wired connection. Network device 106 or AP can be implemented to support standards for transmitting and receiving data using one or more radio frequencies. Those standards and the frequencies they use may be defined by IEEE (e.g., the IEEE 802.11 standard). Network device 106 or AP may be configured and / or used to support public Internet hotspots and / or extend the Wi-Fi signal range of the network over the network.

[0042] In some embodiments, access point or network device 106 may be used for wireless networks (e.g., in a home, vehicle, or building) such as IEEE 802.11, Bluetooth, ZigBee, any other type of radio frequency-based network protocol, and / or variations thereof. Each of the wireless communication devices 102 may include a built-in radio and / or be coupled to a radio. Such wireless communication devices 102 and / or access point or network device 106 may operate according to various aspects of the present disclosure as presented herein to enhance performance, reduce cost and / or size, and / or enhance broadband applications. Each wireless communication device 102 may have the capability to act as a client node seeking access to resources (e.g., data and connections to networked nodes such as servers) via one or more access point or network devices 106.

[0043] The network connection may include any type and / or form of network, and may include any of the following: point-to-point network, broadcast network, telecommunications network, data communication network, computer network. The network topology may be a bus, star, or ring network topology. The network may have any such network topology known to those skilled in the art capable of supporting the operations described herein. In some embodiments, different types of data may be transmitted via different protocols. In other embodiments, the same type of data may be transmitted via different protocols.

[0044] The communication device 102 and the access point or network device 106 can be deployed as any type and form of computing device and / or executed on any type and form of computing device, such as a computer, network device or appliance capable of communicating and performing the operations described herein on any type and form of network. Figure 1B and 1C A block diagram depicting a computing device 100 that can be used to implement embodiments of wireless communication device 102 or network device 106. (See diagram for reference.) Figure 1B and 1C As shown, each computing device 100 includes a processor 121 (e.g., a central processing unit) and a main memory unit 122. Figure 1B As shown, the computing device 100 may include a storage device 128, a mounting device 116, a network interface 118, an I / O controller 123, display devices 124a to 124n, a keyboard 126, and a pointing device 127, such as a mouse. The storage device 128 may include an operating system and / or software. Figure 1C As shown, each computing device 100 may also include additional optional components such as memory port 103, bridge 170, one or more input / output devices 130a to 130n, and cache memory 140 that communicates with the central processing unit or processor 121.

[0045] The central processing unit or processor 121 is any logic circuit system that responds to and processes instructions fetched from main memory unit 122. In many embodiments, the central processing unit or processor 121 is provided by a microprocessor unit, such as a microprocessor unit manufactured by Intel Corporation of Santa Clara, California; a microprocessor unit manufactured by International Business Machines of White Plains, New York; or a microprocessor unit manufactured by Advanced Micro Devices of Sunnyvale, California. The computing device 100 may be based on any of these processors, or any other processor capable of operating as described herein.

[0046] Main memory unit 122 may be one or more memory chips capable of storing data and allowing direct access to any storage location by a microprocessor or processor 121, such as any type or variant of static random access memory (SRAM), dynamic random access memory (DRAM), ferroelectric RAM (FRAM), NAND flash memory, NOR flash memory, and solid-state drive (SSD). Main memory unit 122 may be based on any of the memory chips described above, or any other available memory chip capable of operating as described herein. Figure 1B In the embodiment shown, the processor 121 communicates with the main memory unit 122 via the system bus 150 (described in more detail below). Figure 1C An embodiment of computing device 100 is depicted, wherein the processor communicates directly with main memory unit 122 via memory port 103. For example, in Figure 1C In this context, the main memory unit 122 can be DRDRAM.

[0047] Figure 1C An embodiment is depicted in which the main processor 121 communicates directly with the cache memory 140 via an auxiliary bus (sometimes referred to as a back-side bus). In other embodiments, the main processor 121 uses a system bus 150 to communicate with the cache memory 140. The cache memory 140 typically has a faster response time than the main memory unit 122 and is provided by, for example, SRAM, BSRAM, or EDRAM. Figure 1CIn the embodiments shown, processor 121 communicates with various I / O devices 130 via local system bus 150. Various buses can be used to connect the central processing unit or processor 121 to any of the I / O devices 130, such as VESA VL bus, ISA bus, EISA bus, Micro Channel Architecture (MCA) bus, PCI bus, PCI-X bus, PCI Fast Bus, or NuBus. In embodiments where the I / O device is a video display 124, processor 121 can communicate with the display 124 using an Advanced Graphics Port (AGP). Figure 1C An embodiment of a computer or computer system 100 is depicted, wherein the main processor 121 may communicate directly with the I / O device 130b, for example, via HYPERTRANSPORT, RAPIDIO, or INFINIBAND communication technologies. Figure 1C An embodiment in which local bus and direct communication are mixed is also depicted: processor 121 communicates with I / O device 130a using local interconnect bus, while communicating directly with I / O device 130b.

[0048] Various I / O devices 130a to 130n may be present in the computing device 100. Input devices include keyboards, mice, trackpads, trackballs, microphones, dials, touchpads, touchscreens, and drawing tablets. Output devices include video displays, speakers, inkjet printers, laser printers, projectors, and dye-to-sublimation printers. The I / O devices can be controlled by the I / O controller 123, such as... Figure 1B As shown in the figure. The I / O controller can control one or more I / O devices, such as keyboard 126 and pointing device 127, such as mouse or optical pen. In addition, the I / O devices can also provide storage and / or mounting media for computing device 100. In other embodiments, computing device 100 can provide USB connectivity (not shown) to receive handheld USB storage devices, such as the USB flash drive series devices manufactured by Twintech Industry, Inc. of Los Alamitos, California.

[0049] Refer again Figure 1BThe computing device 100 may support any suitable installation device 116, such as a disk drive, CD-ROM drive, CD-R / RW drive, DVD-ROM drive, flash drive, tape drive of various formats, USB device, hard disk drive, network interface, or any other device suitable for installing software and programs. The computing device 100 may further include storage devices for storing the operating system and other related software, and for storing application software programs (e.g., any program or software 120 for implementing (e.g., configured and / or designed for) the systems and methods described herein), such as one or more hard disk drives or redundant arrays of independent disks. Optionally, any of the installation devices 116 may also be used as storage devices. Furthermore, the operating system and software can be run from bootable media.

[0050] Furthermore, the computing device 100 may include a network interface 118 for interfacing with a network via various connections, including but not limited to standard telephone lines, LAN or WAN links (e.g., 802.11, T1, T3, 56kb, X.25, SNA, DECNET), broadband connections (e.g., ISDN, Frame Relay, ATM, Gigabit Ethernet, SONET-based Ethernet), wireless connections, or some combination of any or all of the above. Connections can be established using various communication protocols (e.g., TCP / IP, IPX, SPX, NetBIOS, Ethernet, ARCNET, SONET, SDH, Fiber Distributed Data Interface (FDDI), RS232, IEEE 802.11, IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE 802.11ac, IEEE 802.11ad, CDMA, GSM, WiMax, and direct asynchronous connections). In one embodiment, computing device 100 communicates with other computing devices 100' via any type and / or form of gateway or tunneling protocol, such as Secure Sockets Layer (SSL) or Transport Layer Security (TLS). Network interface 118 may include a built-in network adapter, network interface card, PCMCIA network card, card bus network adapter, wireless network adapter, USB network adapter, modem, or any other device suitable for interfacing computing device 100 to any type of network capable of communicating and performing the operations described herein.

[0051] In some embodiments, computing device 100 may include or be connected to one or more display devices 124a to 124n. Therefore, any of the I / O devices 130a to 130n and / or I / O controller 123 may include any type and / or form of suitable hardware, software, or a combination of hardware and software to support, enable, or provide computing device 100 with connectivity to and use of display devices 124a to 124n. For example, computing device 100 may include any type and / or form of video adapter, video card, driver, and / or library to interface with, communicate with, connect to, or otherwise use display devices 124a to 124n. In one embodiment, a video adapter may include multiple connectors to interface with display devices 124a to 124n. In other embodiments, computing device 100 may include multiple video adapters, each connected to display devices 124a to 124n. In some embodiments, any portion of the operating system of computing device 100 may be configured to use multiple display devices 124a to 124n. In other embodiments, I / O device 130 may be a bridge between system bus 150 and external communication buses (such as USB bus, Apple Desktop bus, RS-232 serial connection, SCSI bus, FireWire bus, FireWire 800 bus, Ethernet bus, AppleTalk bus, Gigabit Ethernet bus, Asynchronous Transfer Mode bus, Fibre Channel bus, Fibre Bus, Serial Attached Small Computer System Interface bus, USB connection, or HDMI bus).

[0052] Figure 1B and 1CThe computing device 100 of the type described herein can operate under the control of an operating system that controls task scheduling and access to system resources. The computing device 100 can run any operating system, such as any version of Microsoft Windows, different versions of Unix and Linux, any version of MAC OS for Macintosh computers, any embedded operating system, any real-time operating system, any open-source operating system, any proprietary operating system, any operating system for mobile computing devices, or any other operating system capable of running on a computing device and performing the operations described herein. Typical operating systems include, but are not limited to: Android, produced by Google Inc.; Windows 7, 8, and 10, produced by Microsoft Corporation of Redmond, Washington; macOS, produced by Apple Computer of Cupertino, California; WebOS, produced by ResearchInMotion (RIM); OS / 2, produced by International Business Machines of Armonk, New York; and Linux, a free operating system distributed by Caldera Corp. of Salt Lake City, Utah, or any type and / or form of Unix operating system, etc.

[0053] The computer system or computing device 100 may be any workstation, telephone, desktop computer, laptop or notebook computer, server, handheld computer, mobile phone or other portable telecommunications device, media playback device, gaming system, mobile computing device, or any other type and / or form of computing, telecommunications or media device capable of communication. In some embodiments, the computing device 100 may have a different processor, operating system and input device consistent with the device. For example, in one embodiment, the computing device 100 is a smartphone, mobile device, tablet computer or personal digital assistant. Furthermore, the computing device 100 may be any workstation, desktop computer, laptop or notebook computer, server, handheld computer, mobile phone, any other computer, or other form of computing or telecommunications device capable of communication and having sufficient processor power and memory capacity to perform the operations described herein.

[0054] The aspects of the operating environment and components described above will become apparent in the context of the systems and methods disclosed herein.

[0055] B. Station and AP Communication

[0056] This paper discloses a system and method for blind recovery and group detection, which can be derived from the methods described herein and related to... Figure 1A Used by any of the devices described in C. In some embodiments, STA can refer to any device used for communication in a communication system and includes, but is not limited to, fixed, portable, or mobile laptops, desktop personal computers, personal digital assistants, access points, workstations, wearable devices, smartphones, or Wi-Fi phones. In some embodiments, an access point (AP) can refer to a device used to couple one or more non-AP devices (e.g., client or client device) to a network. More specifically, an AP enables non-AP devices to connect to and communicate with the network. In some embodiments, an AP can be a wireless access point (WAP) configured to enable wireless communication between non-AP devices. APs include, but are not limited to, mobile, portable, or fixed hotspots, routers, bridges, or other communication devices. APs or STAs can communicate data in the form of data packets. In some embodiments, a packet or data packet refers to a structured data unit transmitted over a network. A data packet can be an IEEE 802.11 packet. A packet can contain a preamble and a payload. In some embodiments, a packet is a management frame, a data frame, or a control frame. A preamble refers to a portion of a packet. Preambles are used to prepare wireless media for data transmission and to ensure that receiving devices can properly synchronize and decode incoming signals. Preambles may include a synchronization field, a short training field, and a long training field. Preambles can support multi-user MIMO, channel joining, and advanced modulation schemes. In some embodiments, orthogonal frequency domain multiplexed packets refer to packets provided using digital transmission techniques that use multiple subcarriers to transmit data within a single channel. The subcarriers can be closely spaced and transmitted in parallel to carry low bit-rate data. Orthogonal frequency domain multiplexing is commonly used for high data rate transmission over mobile wireless channels, as well as digital audio broadcasting, DSL Internet access, and power line networks. In some embodiments, wideband packets refer to packets using wideband protocols (e.g., single-channel modulation schemes).

[0057] In some embodiments, a radio can refer to a means of wirelessly transmitting data. In some embodiments, a frequency band can refer to a predefined portion of the radio spectrum. For example, a radio frequency band may include a continuous spectrum according to standards such as 5030 to 5990 MHz, 5945 to 7125 MHz, 2401 to 2495 MHz, or the like. A link can refer to a segmentation of a frequency band used for wireless communication between radios, or another communication channel, such as a wired link (e.g., Ethernet) for communication. A link may include frequency segmentation, time segmentation, combinations thereof, or the like. A multi-link single radio (MLSR) can refer to a radio configured to selectively operate on at least two links (e.g., two links in at least one frequency band). For example, an MLSR radio may operate on a link in response to radio spectrum congestion or increase throughput by alternating between transmitting or receiving therebetween. For example, an MLSR may operate on a primary link, a secondary link, etc. In some embodiments, a primary link can refer to a default, initial, or first link available to a means (e.g., a means including an MLSR radio). In some embodiments, an auxiliary link may refer to a non-default, alternative, or second link available to the device (e.g., a device including an MLSR radio). In some embodiments, simultaneous monitoring (e.g., of a frequency band or link) may refer to radio monitoring of multiple frequency bands or links, such that the presence or content of a wireless message on any of the frequency bands or links can be detected. In some embodiments, the content of a message may refer to information in the message body, message header, message preamble, or the like.

[0058] Figure 2 This is a network diagram 300 of a BSS 305 according to some embodiments. The BSS 305 may include an AP 310 (e.g., a mobile AP 310) and one or more STAs (e.g., non-APs). For example, the BSS 305 may include a first STA 315, a second STA 320, and a third STA 322. An AP 312 may also operate near the BSS 305. Various devices of the BSS 305 and AP 312 may detect other BSS (OBSS) communications from one or more OBSSs based on their location, gain, or other characteristics. For example, AP 310 may detect OBSS communications from a first OBSS, or first STA 315 may detect OBSS communications from a second OBSS. One or more sideband links may interconnect the various devices of the BSS 305. For example, sideband links may be different wireless links on the same or different wireless frequency bands (e.g., the 2.4 GHz band) of the same wireless network. In some embodiments, various devices of the BSS 305 are configured for packet detection and blind recovery protocols, as described below.

[0059] The first or second OBSS may include various AP or STA devices. OBSS communication may include uplink transmissions, downlink transmissions, broadcast messages, self-organizing messages, or the like. BSS 305 may include the main and secondary links of the wireless network's frequency band. In some embodiments, BSS 305 may employ sideband communication between BSS 305 and various OBSSs.

[0060] refer to Figure 3A Device 221 is one of AP 310 or 312 or STA 315, 320 and 322. Figure 2 It is configured for the protocols and operations described below according to some embodiments. In some embodiments, device 221 includes processing circuitry 233, spectrum detection module 239, and traffic detection module 243. In some embodiments, processing circuitry 233 is any circuit system or component capable of performing logic and communication processing operations and may include processor 235 and memory 237.

[0061] In some embodiments, the processing circuit 233 is implemented as a field-programmable gate array, an application-specific integrated circuit, a hardware or software execution processor, or a state machine. In some embodiments, the processing circuit 233 is part of a layer (e.g., MAC, network, PHY layer) of an IEEE 802.11 standard device. In some embodiments, the processing circuit 233 may be configured to perform communication operations, frame construction and processing, discovery operations, association operations, authorization operations, connection establishment, deassociation operations, handover operations, detection operations, and deauthentication operations. In some embodiments, the instructions of the processing circuit 233 are stored in a non-transitory medium, such as memory 237.

[0062] Memory 237 may be one or more means (e.g., RAM, ROM, flash memory, hard disk storage) for storing data and / or computer code used to perform and / or facilitate the various processes described herein. Memory 237 may be or include non-transient volatile memory, non-volatile memory, and non-transitory computer storage media. Memory 237 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein. Memory 237 may be communicatively coupled to processor 235 and contains computer code or instructions for performing one or more processes described herein. Processor 235 may be implemented as one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), a group of processing components, software execution processors, state machines, or other suitable electronic processing components. Thus, AP or network device 106 ( Figure 1AThe system is configured to execute various modules and / or programs and store associated data in a database in memory 237. Modules (e.g., modules 239 and 243) may be implemented in AP software (e.g., MAC layer or PHY layer software) or STA software (e.g., MAC layer or PHY layer software). In some embodiments, AP 310 or STA 315 ( Figure 2 Structured and used to establish connections to other computing systems and devices (e.g., wireless communication device 102, network hardware 192, other access points or network devices 106) via networks (e.g., WAN connections, LAN connections, WLAN connections, etc.). Figure 1A Connect to C) and switch access to it.

[0063] In some embodiments, the spectrum detection module 239 and the service detection module 243 are configured to provide frame detection and / or blind recovery operations. For example, the spectrum detection module 239 and the service detection module 243 may be configured to detect the presence of a packet or a portion thereof even if the packet (e.g., a WLAN OFDM packet) or a portion thereof has low signal strength. In some embodiments, OFDM packets are detected even if the preamble is missed due to blindness.

[0064] In some embodiments, the spectrum detection module 239 is configured to sample spectral characteristics on the media channel, and the traffic detection module 243 is configured to perform spectrum analysis to detect the presence of packets. In some embodiments, the traffic detection module 243 is configured to compare the components of the sample with the expected spectrum of any packet (e.g., an OFDM WLAN packet). If the sample matches or sufficiently matches the expected spectrum, then a packet is detected. In some embodiments, the traffic detection module 243 receives spectrum analysis in the form of per-frequency energy and compares the energy on the loaded and unloaded tones with the expected energy of the guard tone. If the energy spectrum matches or sufficiently matches the energy of the expected guard tone and signal tone, then a packet is detected. In some embodiments, this comparison allows differentiation of any WLAN OFDM packet from other over-the-air signals without any timing or frequency synchronization. In some embodiments, the traffic detection module 243 receives spectrum analysis in the form of per-frequency energy and compares the energy on the loaded and unloaded tones with the expected energy of the pilot tone. If the energy spectrum matches or sufficiently matches the energy of the expected pilot tone and signal tone, then a packet is detected. In some embodiments, the traffic detection module 243 detects over-the-air OFDM packets and, in some embodiments, includes a cyclic prefix (CP) detector. In some embodiments, the service detection module 243 uses the autocorrelation of the time-domain signal across different hysteresis to determine the OFDM symbol length and thereby detect the presence of an over-the-air OFDM signal or packet.

[0065] In some embodiments, a guard tone refers to a subcarrier frequency used to provide signal (data) in the signal spectrum (e.g., OFDM signal spectrum). In some embodiments, a guard tone refers to an unused subcarrier frequency at the edge of the signal spectrum (e.g., OFDM signal spectrum). Guard tones are not modulated by data and are essentially left as 0 or "empty" subcarriers. In some embodiments, guard tones help mitigate interference and prevent overlap between adjacent channels or subcarriers. Guard tones are also called guard bands or guard subcarriers and can be edge guard tones or center guard tones (e.g., in some embodiments, pilot tones refer to subcarrier signals that provide a known reference signal). In some embodiments, pilot tones are typically placed at regular intervals within the spectrum (OFDM spectrum), which allows the receiver to interpolate channel state information across all subcarriers, thereby ensuring accurate channel estimation across the entire signal bandwidth. According to some IEEE 802.11 standards, in a 20 MHz bandwidth with 64 subcarriers, 4 tones are pilot tones and 12 tones are guard tones.

[0066] The spectrum detection module 239 may use any technology and / or circuit system to sample energy in the spectrum. The spectrum detection module 239 may include spectrum sampling circuitry that measures the magnitude of the input signal and frequencies within a specified frequency range. The spectrum detection module 239 may use one or more radios associated with device 221 to scan Wi-Fi channels. The spectrum detection module 239 may be a physical layer device and may be controlled by software (e.g., MAC layer software). The spectrum detection module 239 may select one or more channels and channel widths for obtaining spectrum data. The spectrum data may include RSSI data. Fast Fourier Transform (FFT) technology may be utilized. In some embodiments, the spectrum detection module 239 may utilize one or more radios and may use multiple radios to perform simultaneous detection on multiple bands or channels.

[0067] In some embodiments, the spectrum detection module 239 acquires 2812.8 microsecond samples for full bandwidth (BW) spectrum analysis. In some embodiments, the full BW may encompass each 20 MHz sub-band in the link. The spectrum detection module 239 detects the presence of airborne OFDM packets in any sub-band. In some embodiments, each sub-band may be examined to determine whether a packet is a wideband packet. The traffic detection module 243 may use any technology and / or circuitry to compare the spectrum data from the spectrum detection module 239 with the expected spectrum indicating an idle or used channel. The expected data may include RSSI data. The traffic detection module 243 may include memory for storing expected guard tone or pilot tone.

[0068] The service detection module 243 may be a physical layer device or may be implemented by software (e.g., MAC layer software). In some embodiments, a pattern matching circuitry system or software may be utilized. In some embodiments, the service detection module 243 detects a service in less than 25 microseconds (e.g., less than 12.8 microseconds). In some embodiments, the spectrum detection module 239 samples tones other than one or more guard tones. The sampling period may be the time associated with the expected presence of such tones when the channel is in use. Data associated with the samples is provided to the service detection module 243, which divides the energy of the non-guard tone by the energy of the guard tone (e.g., its average value) or subtracts the energy of the guard tone from the energy of the non-guard tone. The service detection module 243 compares the quotient or difference with an expected threshold. If the energy is higher than the threshold, then the presence of a service is detected.

[0069] refer to Figure 3B Figure 330 includes an X-axis 334 representing frequency and a Y-axis 332 representing energy. The X-axis 334 can represent network 300 (…). Figure 2 The bandwidth of the channel in (). In some embodiments, the bandwidth of curve 340 is 20 MHz. Curve 340 represents the energy level at frequencies associated with signal tones E1 to E4 and guard tones G1 and G2. Tones E1 to 4 and G1 to 2 represent six zones.

[0070] In some embodiments, tones E1 to E4 may not necessarily have energy, and the energies E1E to E4E are four consecutive segments of average power (tones E1 to E4). In some embodiments, tones E1 and E4 are adjacent to guard tones G1 and G2. The energies of guard tones G1 and G2 are G1E and G2E, respectively. According to the WiFi protocol, guard tones G1 and G2 are empty tones and have minimum or low energy. Tones E1 to E4 are fill tones and have energies E1E to E4E, respectively. As discussed above, the fill tone energies E1E to E4E are compared with the average guard tone energies G1E and G2E to determine the presence of packets. The presence of packets can be checked for every 20 MHz bandwidth. In some embodiments, guard tones G1 and G2 may represent a group of tones and are edge tones.

[0071] In some embodiments, the service detection module 243 compares the energy E1E through E4E with a power threshold associated with the noise detected in the broadband detection. If each of the energies E1E through E4E is higher than the noise power threshold (e.g., -90 to -60 dBm, -72 dBm), then the activity is in all four tones E1 through E4, or wide enough to be classified as a broadband packet. Since the minimum transmit unit in a WLAN is 20 MHz, this condition of four tones exceeding the threshold reduces the probability of false alarms by discarding the detection of any narrowband signal. In some embodiments, if each of the energies E1E and E4E (adjacent tones G1 and G2) is higher than the noise power threshold (e.g., -90 to -60 dBm, -72 dBm), then the activity can be classified as a broadband packet. For offloading criteria (e.g., one of E1E to E4E is less than a noise threshold), the presence of a guard band is checked using the condition E1E - G1E > threshold(th) or E4E - G2E > threshold, which indicates the spectral shape of the WLAN signal at the two edges of the waveform associated with curve 340. In some embodiments, since the number of samples required is the same as the FFT size, detection can be performed within 12.8 microseconds without additional hardware. If two of these conditions (all energies E1E to E4E are above the noise threshold and E1E - G1E > th or E4E - G2E > th) are met in a particular sub-band, then the particular sub-band has Wi-Fi energy and OFDM packets are present. If none of these conditions are met, then synchronization can begin.

[0072] Exemplary numbers of guard tones for different types of WiFi packets are given in Table 1 below. The number of edge guard tones for non-high throughput (HT), HT, and very high throughput (VHT) packets is increased by a factor relative to high efficiency (HE) / very high frequency (EHT) packets. In some embodiments, guard tones are present only in edge subbands, and the guard tones are present only on the edge side. In some embodiments, guard tone power or energy (G1E and G2E) can be calculated according to the HE 20 MHz tone scheme. Loaded tone power or energy (E1E, E2E, E3E, E4E) for comparison can be calculated according to the non-HT 20 MHz BW tone scheme.

[0073]

[0074] Table 1 – Number of Protected Pitches

[0075] As shown in Table 1, a minimum number of guard tones are present in the bandwidth of the HE / EHT configuration. In some embodiments, module 243 uses the number of tones in the G1 subband subgroup and G2 subgroup as 5 or 6, and allocates the remaining loaded tones in E1, E2, E3, and E4. This allows the detection of the presence of packets in non-HT, HT, VHT, and HE / EHT configurations. For example, the guard tone size is 6 tones in G1 and 5 tones in G2, and the remaining tones are distributed in E1, E2, E3, and E4 to check for broadband criterion one (one of E1E to E4E being below a noise threshold indicates a non-broadband packet). In some embodiments, running this configuration is sufficient to obtain information about the presence of Wi-Fi packets because it is not necessary to subdivide the groups into subclasses.

[0076] refer to Figures 3A to 4 Service detection and blind recovery can be performed using procedure 400. In operation 402, spectral energy (e.g., G1E, G2E, E1E to E4E) is obtained. At operation 402, the spectral energy E1E to E4E of tones E1 to E4 is compared with the spectral energy G1E and G2E. Average energy values ​​can be used. At operation 404, a comparison is made to detect the presence of service. If both conditions (one of the energies E1E to E4E is below a noise power threshold and E1E - G1E > th or E4E - G2E > th) are met on a specific sub-band, then the specific sub-band has Wi-Fi energy and OFDM packets are present. In some embodiments, if broadband or OFDM service is not present, device 221 can synchronize on the channel and recover from blind recovery. In some embodiments, unlike standard synchronization and collision detection procedures, synchronization can occur immediately. Procedure 400 can also be used after a sleep mode. In some embodiments, the noise power threshold or noise threshold represents a certain amount of energy (above which the signal cannot be noise) and may be a signal-to-noise threshold.

[0077] refer to Figures 3A to 5 Service detection and blind recovery can be performed using a process 500, similar to process 400. In operation 502, spectral energy (e.g., G1E, G2E, E1E to E4E) is obtained, and in operations 560 and 508, the presence of packets in the sub-bands is checked. If packets are present in the sub-bands, then all other sub-bands are checked. In some embodiments, unused sub-bands can be used for puncture communication. All sub-bands for a specific configuration or operation can be checked, and the data can be unified to determine the total BW of the signal or packet. For example, in some embodiments, if energy is detected in the first and last sub-bands, then the packet is detected as an 80MHz packet.

[0078] In some embodiments, if the packet is not present, device 221 can synchronize on the channel and recover from the blind. If the packet is present, device 221 determines in operation 510 whether all desired channels have been checked. If not, device 221 proceeds to operation 502 and checks another channel. If yes, device 221 waits and returns to operation 502 or begins normal synchronization at an appropriate time. Operations 502, 506, and 508 can use process 400.

[0079] refer to Figure 6 Figure 600 includes an X-axis 604 representing the power difference and a Y-axis 602 representing the probability of packet presence based on the maximum value among (E1E-G1E and E4E-G2E). In some embodiments, the power difference is the reference power minus the edge power (which are the average power E1E and E4E minus the average G1E and G2E, respectively). Curves 612, 614, 616, and 618 represent signals at energy levels of -78 dBm, -81 dBm, -84 dBm, and -87 dBm. An 8 dB power difference threshold for packet detection provides a reliable threshold for the signals represented by curves 612, 614, 616, and 618. In some embodiments, the signals are each 20 MHz bandwidth AWGN OFDM signals transmitted through a channel affected by AWGN.

[0080] refer to Figure 7 Figure 700 includes an X-axis 704 representing the power difference and a Y-axis 702 representing the probability of grouping based on the maximum value among (E1E-G1E and E4E-G2E). Figure 700 shows the false alarm probability of a random Gaussian signal. The power difference is the reference power minus the edge power (which is the average power E1E and E4E minus the average G1E and G2E, respectively). Curve 712 shows that for an 8 dBm power difference threshold, the false alarm probability is less than 0.5%.

[0081] Therefore, in general, a better understanding of embodiments of the above-described devices and processes can be achieved by referring to the IEEE 802.11 standard, which provides additional details regarding certain signals and operations disclosed herein, and is not intended to limit the above-described devices or processes in any way. The (IEEE) standards (specifically 802.11-2020; 802.11ax) are hereby fully incorporated into this disclosure. TM -2021 IEEE Std 802.11ax™-2021: Enhanced High-Efficiency WLAN (Amendment 1), IEEE P802.11be™ / D2.2 and IEEE P802.11-REVme™ / D1.3). In some embodiments, WiFi network may refer to a wireless network with Internet access.

[0082] A circuit system or circuit can refer to any electronic circuit or combination of circuits. Where a device, circuit, processor, or circuit system is described or cited in the claims as performing or configured to perform one or more operations or functions, the performance of the cited function or operation may be distributed across two or more devices, circuits, or processors without departing from the scope of the claims, unless those functions or operations are expressly cited as being performed on a particular single circuit or group of circuits, processors, or devices (e.g., using the phrases "to a single circuit," "to a group of circuits including," or "to a single device").

[0083] It should be noted that certain paragraphs of this disclosure may refer to terms such as “first” and “second” in relation to subsets of transmit space streams, probe frames, responses, and devices for identification or distinction from one another. These terms are not intended to associate entities (e.g., first and second devices) merely temporally or sequentially, although in some cases these entities may include such a relationship. These terms also do not limit the number of possible entities (e.g., STA, AP, beamformer, and / or beamformee) that can operate within the system or environment. It should be understood that the described system may provide any or multiple of those components, and these components may be provided on a standalone machine or, in some embodiments, on multiple machines in a distributed system. Furthermore, bit field positions may be changed, and multiple bit words may be used. Additionally, the described system and method may be provided as one or more computer-readable programs or executable instructions embodied on or in one or more articles of manufacture (e.g., floppy disk, hard disk, CD-ROM, flash memory card, PROM, RAM, ROM, or magnetic tape). The program can be implemented in any programming language (e.g., LISP, PERL, C, C++, C#) or in any bytecode language (e.g., JAVA). The software program or executable instructions can be stored as object code on or in one or more artifacts.

[0084] While the foregoing written description of the methods and systems enables those skilled in the art to make and use embodiments thereof, it should be understood and appreciated that variations, combinations, and equivalents of specific embodiments, methods, and examples exist herein. Therefore, the methods and systems of the present invention should not be limited to the foregoing embodiments, methods, and examples, but rather to all embodiments and methods within the scope and spirit of this disclosure.

Claims

1. A first device comprising: antenna; A circuit configured to provide data to a second device via the antenna across a connection including one or more links, wherein the circuit is configured to detect the presence of at least a portion of a packet using the relationship between the guard tone and the signal tone in the bandwidth, and to synchronize to the channel if the packet is not present.

2. The first device according to claim 1, wherein the bandwidth is 20 MHz.

3. The first apparatus of claim 1, wherein the circuitry is configured to detect the presence using the relationship between the signal pitch and a first threshold.

4. The first device according to claim 3, wherein the first threshold is a fixed threshold.

5. The first apparatus of claim 1, wherein the circuitry is configured to detect the presence by comparing the relationship between the guard tone and the signal tone in the bandwidth with a second threshold.

6. The first apparatus according to claim 1, wherein the group is an orthogonal frequency domain multiplexed group.

7. The first apparatus according to claim 1, wherein the packet is a broadband packet.

8. The first device according to claim 5, wherein the circuit is part of an access point or station.

9. A first device comprising: antenna; A circuit configured to provide packets to a second device using the antenna across a connection including one or more links, wherein the circuit includes a spectrum module configured to provide spectral data indicating energy in a bandwidth and a detector configured to use the spectral data to detect the presence of at least a portion of the packets in response to the energy relationship between a guard tone and a signal tone in the bandwidth.

10. The first apparatus of claim 9, wherein the circuitry is used for recovery from the blind.

11. The first apparatus of claim 9, wherein the circuitry is configured to detect the packet without detecting the preamble.

12. The first apparatus of claim 9, wherein the spectrum data includes a Received Signal Strength Indicator (RSSI) value.

13. The first apparatus of claim 9, wherein the detector is configured to detect the presence using the relationship between the guard tone in the bandwidth and the signal tone.

14. The first apparatus of claim 13, wherein the detector is configured to detect the presence using a set of signal tones in relation to a first threshold.

15. The first apparatus of claim 13, wherein the relationship between the protective tone and the signal tone is compared with a threshold.

16. The first device according to claim 15, wherein the threshold is 8 dB.

17. A method for blind recovery from a communication system, the method comprising: Use antennas to provide spectral data indicating energy for bandwidth; Using the spectral data, a first relationship between a set of signal tones within the bandwidth is determined to be higher than a first threshold; and The spectrum data is used to determine a second relationship between the energy of the guard tone and the signal tone in the bandwidth; The presence of at least a portion of the group is detected in response to the first relation and the second relation.

18. The method of claim 17, wherein the second relationship is the difference between the energy of the guard tone and the signal tone.

19. The method of claim 17, wherein the first relationship is a comparison of the signal pitch with a threshold.

20. The method of claim 19, wherein the threshold is a noise threshold.

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