Padding and backoff operations during transmission over multiple frequency segments in WLA

Abstract

The communication device determines that simultaneous transmission and reception over multiple frequency segments in the WLAN is not permitted. The communication device transmits a first packet in a first frequency segment starting at a first time, and transmits a second packet in a second frequency segment starting at a second time different from the first time. The transmission of the second packet overlaps temporally with the transmission of the first packet. In response to the determination that simultaneous transmission and reception over multiple frequency segments is not permitted, the communication device includes padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet.

Description

Technology Field

[0001] This application claims the benefit of U.S. provisional patent application No. 62 / 863,699, titled “Multi-Band Operation: Synchronized and Unsynchronized,” filed on June 19, 2019, the full text of which is incorporated herein by reference.

[0002] The present disclosure relates generally to wireless communication systems, and more specifically to simultaneous transmission and / or reception in multiple frequency segments in a wireless local area network (WLAN). Background Technology

[0003] Over the past 20 years, Wireless Local Area Networks (WLANs) have evolved rapidly, and advancements in WLAN standards, such as the IEEE 802.11 family, have improved peak data rates for a single user. One way to increase data rates is to increase the frequency bandwidth of the communication channels used in WLANs. For example, the IEEE 802.11n standard allows the aggregation of two 20 MHz sub-channels to form a 40 MHz aggregated communication channel, whereas the more recent IEEE 802.11ax standard allows the aggregation of up to eight 20 MHz sub-channels to form aggregated communication channels of up to 160 MHz. Work has now begun on a new iteration of the IEEE 802.11 standard, referred to as the IEEE 802.11be standard or EHT (Extremely High Throughput) WLAN. The IEEE 802.11be standard may allow the aggregation of 16 (or possibly more) 20 MHz sub-channels to form up to 320 MHz aggregated communication channels (or possibly wider aggregated communication channels). Additionally, the IEEE 802.11be standard may allow the aggregation of 20 MHz sub-channels from different frequency segments (e.g., separated by a gap in frequency) to form individual communication links. Furthermore, the IEEE 802.11be standard may aggregate 20 MHz sub-channels from different RF (radio frequency) bands to form a single aggregated channel, or aggregate 20 MHz sub-channels from different RF bands to form individual communication links.

[0004] The latest IEEE 802.11 standard (referred to as "IEEE 802.11 standard" in this specification for the sake of simplicity) provides for a first communication device to transmit packets to a second communication device over a single communication channel. The IEEE 802.11 standard also provides mechanisms for the device to determine whether the single communication channel is busy or idle for the purpose of determining whether the device can transmit over the single communication channel.

[0005] In one embodiment, a method for transmitting simultaneously across a plurality of frequency segments comprises: determining in a communication device that simultaneous transmission and reception through a plurality of frequency segments is not permitted; transmitting a first packet in a first frequency segment starting at a first time by the communication device; transmitting a second packet in a second frequency segment starting at a second time different from the first time by the communication device, wherein the transmission of the second packet temporally overlaps with the transmission of the first packet; and, in response to the determination that simultaneous transmission and reception through a plurality of frequency segments is not permitted, including padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet.

[0006] In another embodiment, the first communication device includes a wireless network interface device configured to communicate over a plurality of frequency segments. The wireless network interface device determines that simultaneous transmission and reception over the plurality of frequency segments is not permitted; controls the wireless network interface device to transmit a first packet in a first frequency segment starting at a first time; controls the wireless network interface device to transmit a second packet in a second frequency segment starting at a second time different from the first time, wherein the transmission of the second packet temporally overlaps with the transmission of the first packet; and includes one or more integrated circuit (IC) devices configured to include padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet in response to the determination that simultaneous transmission and reception over the plurality of frequency segments is not permitted.

[0007] In another embodiment, a method for transmitting simultaneously in a plurality of frequency segments comprises: a step of performing a backoff operation corresponding to one of the plurality of frequency segments in a communication device, wherein the backoff operation involves decrementing a backoff counter in relation to one frequency segment; a step of determining whether the backoff counter of the communication device has expired in the communication device; and a step of transmitting each transmission in each of the frequency segments that start simultaneously by the communication device in response to the determination that the backoff counter has expired.

[0008] In another embodiment, the communication device includes a wireless network interface device configured to communicate over a plurality of frequency segments. The wireless network interface device includes one or more IC devices and a backoff counter implemented on one or more IC devices. The one or more IC devices are configured to: perform a backoff operation corresponding to one of the plurality of frequency segments, wherein the backoff operation involves decrementing the backoff counter in relation to one frequency segment; determine whether the backoff counter has expired; and, in response to the determination that the backoff counter has expired, control the wireless network interface device to simultaneously transmit each of the transmissions on each of the frequency segments that start simultaneously. Brief explanation of the drawing

[0009] FIG. 1 is a block diagram of an exemplary communication system in which communication devices wirelessly exchange information through a plurality of frequency segments according to one embodiment. FIG. 2a is a diagram of an exemplary communication channel used by the communication system of FIG. 1 according to one embodiment, and the communication channel corresponds to a plurality of frequency segments. FIG. 2b is a diagram of another exemplary communication channel used by the communication system of FIG. 1 according to another embodiment, and the communication channel corresponds to a plurality of frequency segments. FIG. 3 is a block diagram of an exemplary wireless network interface device configured to communicate through a plurality of frequency segments according to one embodiment. FIG. 4 is a diagram of an example of unsynchronized transmissions in a plurality of frequency segments according to one embodiment. FIG. 5 is a flowchart of an exemplary method for transmitting simultaneously in a plurality of frequency segments according to one embodiment. FIG. 6 is a flowchart of another exemplary method for transmitting simultaneously in a plurality of frequency segments according to one embodiment. FIG. 7 is a diagram of an example of synchronized and simultaneous transmissions in a plurality of frequency segments according to one embodiment. FIG. 8 is a diagram of another example of synchronized and simultaneous transmissions in a plurality of frequency segments according to another embodiment. FIG. 9 is a flowchart of another exemplary method for transmitting simultaneously in a plurality of frequency segments according to one embodiment. FIG. 10 is a diagram of another example of synchronized and simultaneous transmissions in a plurality of frequency segments according to another embodiment. FIG. 11 is a diagram of an example of synchronized and simultaneous transmissions in a plurality of frequency segments according to another embodiment. Specific details for implementing the invention

[0010] Next-generation wireless local area network (WLAN) protocols (e.g., the IEEE 802.11be standard, sometimes referred to as the EHT (Extremely High Throughput) WLAN standard) may allow the aggregation of 16 (or possibly more) 20 MHz sub-channels to form 320 MHz aggregated communication channels (or possibly wider aggregated communication channels). Additionally, the IEEE 802.11be standard may allow the aggregation of 20 MHz sub-channels from different frequency segments (e.g., separated by frequency gaps) to form individual communication links. Furthermore, the IEEE 802.11be standard may allow the formation of multiple WLAN communication links corresponding to individual frequency segments. Multiple WLAN communication links may be used to transmit / receive different information simultaneously.

[0011] In some embodiments described below, multiple packets are transmitted simultaneously in respective frequency segments starting at different times. Padding is included in one or more packets so that the transmission of multiple packets is terminated simultaneously.

[0012] In some embodiments described below, each backoff operation is performed in relation to each frequency segment to determine when simultaneous transmissions in multiple frequency segments can begin. In other embodiments described below, a single backoff operation is performed in relation to only one frequency segment to determine when simultaneous transmissions in multiple frequency segments can begin.

[0013] FIG. 1 is a diagram of an exemplary WLAN (110) using multiple communication links in multiple frequency segments or different radio frequency (RF) bands according to one embodiment. The WLAN (110) includes an access point (AP) (114) comprising a host processor (118) coupled to a wireless network interface device (122). The wireless network interface device (122) includes one or more media access control (MAC) processors (126) (sometimes referred to herein as "MAC processor (126)" for brevity) and one or more PHY processors (130) (sometimes referred to herein as "PHY processor (130)" for brevity). The PHY processor (130) includes a plurality of transceivers (134), and the transceivers (134) are coupled to a plurality of antennas (138). Although three transceivers (134) and three antennas (138) are illustrated in FIG. 1, the AP (114) includes other suitable numbers (e.g., 1, 2, 4, 5, etc.) of transceivers (134) and antennas (138) in other embodiments. In some embodiments, the AP (114) includes a greater number of antennas (138) than transceivers (134), and antenna switching techniques are used.

[0014] In one embodiment, the wireless network interface device (122) is configured to operate within a single RF band at a given time. In one embodiment, the wireless network interface device (122) is configured to communicate simultaneously via multiple communication links in each frequency segment within a single RF band and / or to communicate via multiple communication links at different times. In another embodiment, the wireless network interface device (122) is additionally configured for operation within two or more RF bands simultaneously or at different times. For example, in one embodiment, the wireless network interface device (122) is configured to communicate simultaneously via multiple communication links in each RF band and / or to communicate via multiple communication links at different times. In one embodiment, the wireless network interface device (122) includes multiple PHY processors (130), wherein each PHY processor (130) corresponds to each RF band. In another embodiment, the wireless network interface device (122) includes a single PHY processor (130), wherein each transceiver (134) includes each RF radio corresponding to each RF band.

[0015] The wireless network interface device (122) is implemented using one or more integrated circuits (ICs) configured to operate as described below. For example, the MAC processor (126) may be implemented at least partially on the first IC, and the PHY processor (130) may be implemented at least partially on the second IC. The first IC and the second IC may be packaged together within a single IC package to form a modular device, or the first IC and the second IC may be combined together on a single printed board, for example, in various embodiments. As another example, at least a portion of the MAC processor (126) and at least a portion of the PHY processor (130) may be implemented on a single IC. For example, the wireless network interface device (122) may be implemented using a system-on-chip (SoC), wherein the SoC includes at least a portion of the MAC processor (126) and at least a portion of the PHY processor (130).

[0016] In one embodiment, the host processor (118) includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as random access memory (RAM), read-only memory (ROM), flash memory, etc. In one embodiment, the host processor (118) may be implemented at least partially on a first IC, and the network device (122) may be implemented at least partially on a second IC. As another example, at least part of the host processor (118) and the wireless network interface device (122) may be implemented on a single IC.

[0017] In various embodiments, the MAC processor (126) and / or PHY processor (130) of the AP (114) are configured to generate data units according to a WLAN communication protocol, such as a communication protocol according to the IEEE 802.11 standard or other suitable wireless communication protocol, and to process the received data units. For example, the MAC processor (126) may be configured to implement MAC layer functions including MAC layer functions of the WLAN communication protocol, and the PHY processor (130) may be configured to implement PHY functions including PHY functions of the WLAN communication protocol. For example, the MAC processor (126) is configured to generate MAC layer data units, such as MSDU (MAC service data unit), MPDU (MAC protocol data unit), etc., and to provide the MAC layer data units to the PHY processor (130). Additionally, in some embodiments, the MAC processor (126) is configured to select communication links to which the MAC layer data units are to be transmitted and to control the PHY processor (130) so that the MAC layer data units are transmitted on the selected communication links. Additionally, in some embodiments, the MAC processor (126) is configured to determine when each communication link is idle and available for transmission, and to control the PHY processor (130) so that MAC layer data units are transmitted when each communication link is idle. Additionally, in some embodiments, the MAC processor (126) is configured to determine when client stations are in a sleep state and are therefore not available for transmission or reception.For example, according to some embodiments, the MAC processor (126) is configured to negotiate a schedule with the client station regarding when the client station is allowed to be in a sleep state and when the client station must be in a wake state and can transmit to or receive from the AP (114).

[0018] A PHY processor (130) may be configured to receive MAC layer data units from a MAC processor (126) and encapsulate the MAC layer data units for transmission through antennas (138) to generate PHY data units such as PHY protocol data units (PPDUs). Similarly, a PHY processor (130) may be configured to receive PHY data units received through antennas (138) and extract MAC layer data units encapsulated within the PHY data units. The PHY processor (130) may provide the extracted MAC layer data units to a MAC processor (126) that processes MAC layer data units.

[0019] PHY data units are sometimes referred to as "packets" in this specification, and MAC layer data units are sometimes referred to as "frames" in this specification.

[0020] In relation to generating one or more RF signals for transmission, a PHY processor (130) is configured, according to one embodiment, to process data corresponding to a PPDU (which may include modulation, filtering, etc.) to generate one or more digital baseband signals, and to convert the digital baseband signal(s) into one or more analog baseband signals. Additionally, the PHY processor (130) is configured to upconvert one or more analog baseband signals into one or more RF signals for transmission through one or more antennas (138).

[0021] In relation to receiving one or more RF signals, the PHY processor (130) is configured to downconvert one or more RF signals into one or more analog baseband signals and convert one or more analog baseband signals into one or more digital baseband signals. The PHY processor (130) is further configured to process one or more digital baseband signals (which may include demodulation, filtering, etc.) to generate a PPDU.

[0022] The PHY processor (130) in various embodiments includes amplifiers (e.g., low-noise amplifier (LNA), power amplifier, etc.), RF downconverter, RF upconverter, a plurality of filters, one or more analog-to-digital converters (ADCs), one or more digital-to-analog converters (DACs), one or more discrete Fourier transform (DFT) calculators (e.g., fast Fourier transform (FFT) calculators), one or more inverse discrete Fourier transform (IDFT) calculators (e.g., inverse fast Fourier transform (IFFT) calculators), one or more modulators, one or more demodulators, etc.

[0023] The PHY processor (130) is configured to generate one or more RF signals provided to one or more antennas (138). The PHY processor (130) is also configured to receive one or more RF signals from one or more antennas (138).

[0024] The MAC processor (126) is configured to control the PHY processor (130) to generate one or more RF signals by, for example, providing one or more MAC layer data units (e.g., MPDUs) to the PHY processor (130) according to some embodiments, and optionally by providing one or more control signals to the PHY processor (130). In one embodiment, the MAC processor (126) includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as RAM, ROM, flash memory, etc. In another embodiment, the MAC processor (126) additionally or alternatively includes one or more hardware state machines.

[0025] According to some embodiments, the MAC processor (126) includes or implements a backoff controller (140) configured to implement a backoff procedure in relation to determining when transmission in a communication channel can proceed. The backoff controller (140) includes one or more backoff counters (sometimes referred to as timers) (142). When the network interface device (122) transmits, and when the network interface device (122) determines that the transmission of a data unit has failed and will be retransmitted, the backoff controller (140) calls a backoff procedure. The backoff procedure generally includes the steps of setting the backoff counter (142) and decrementing the backoff counter (142) to determine when the network interface device (122) can transmit a frame.

[0026] The backoff counter (142) is set to a value selected randomly or pseudo-randomly, according to some embodiments, such that the backoff counters of different communication devices in the network tend to reach zero at different times. While the backoff controller (140) determines that the channel medium is idle, the backoff controller (140) controls the backoff counter (142) to decrement. Meanwhile, if the backoff controller (140) determines that the communication medium is busy, the backoff controller (140) pauses the backoff counter (142) and does not resume decrement of the backoff counter (142) until the communication medium is subsequently determined to be idle. Generally, when the backoff counter (142) reaches zero, the backoff controller (140) determines that the communication device is free to transmit. In some embodiments, prior to transmission, the network interface device (122) also determines whether the sub-channel(s) on which transmission is to occur are idle for a determined time period immediately prior to the start of transmission. In some embodiments, the backoff counter (142) reaches 0, but when the sub-channel(s) on which transmission is to occur are not idle for a determined time period immediately prior to the start of transmission, transmission is not performed and the backoff counter is reset.

[0027] In one embodiment, the step of determining whether the channel medium is idle includes measuring an energy level in the channel medium and comparing the measured energy level with a threshold. According to one embodiment, if the measured energy level is less than the threshold, the channel medium is determined to be idle; whereas if the measured energy level meets the threshold (e.g., greater than the threshold, greater than or equal to the threshold, etc.), the channel medium is determined to be busy. In some embodiments, the PHY processor (130) includes one or more energy sensors (not shown) that measure energy levels in one or more frequency segments of a communication channel, and the measured energy levels are used to determine whether the channel medium is idle.

[0028] In one embodiment, setting the backoff counter (142) involves randomly or pseudo-randomly selecting an initial value for the backoff counter (142) from a range of initial values. In one embodiment, the range of initial values ​​is [0, CW], where CW is a contention window parameter, and the initial value and CW are units of slots, each slot corresponding to an appropriate time period. For example, the IEEE 802.11 standard defines slot times of 20 microseconds and 9 microseconds (IEEE 802.11a, 11n, and 11ac), where different slot times are used for different versions of the protocol. In one embodiment, CW is initially set to a minimum value CWmin. However, after each failed transmission attempt (e.g., failure to receive an acknowledgment of transmission), the value of CW is approximately doubled to the upper limit of CWmax. The parameters CWmin and CWmax are also units of slots. In one embodiment, the backoff counter (142) is decremented in slot units.

[0029] In some embodiments, when the communication channel includes a plurality of frequency segments, a plurality of backoff counters (142) are maintained for the plurality of frequency segments in at least some scenarios. In some embodiments, when the communication channel includes a plurality of frequency segments, a single backoff counter (142) is maintained for one of the plurality of frequency segments in at least some scenarios.

[0030] In various embodiments, the backoff controller (140) performs various operations related to one or more backoff counters (142), such as (or none of) one or more of: i) determining whether to use a plurality of backoff counters (142) corresponding to each frequency segment when transmitting simultaneously through a plurality of frequency segments; ii) selecting one frequency segment corresponding to the single backoff counter (142) when a single backoff counter (142) is used when transmitting simultaneously through a plurality of frequency segments.

[0031] In one embodiment, the backoff controller (140) is implemented by a processor that executes machine-readable instructions stored in memory, wherein the machine-readable instructions cause the processor to perform operations described in more detail below. In another embodiment, the backoff controller (140) additionally or alternatively includes a hardware circuit (e.g., one or more counters, one or more timers, one or more hardware state machines, etc.) configured to perform operations described in more detail below. In some embodiments where the hardware circuit includes one or more hardware state machines, the one or more hardware state machines are configured to perform operations described in more detail below.

[0032] Additionally or alternatively, the MAC processor (126) includes or implements a synchronized transmit controller (146) configured to determine when multiple transmits in multiple frequency segments are synchronized (e.g., multiple transmits start simultaneously and optionally end simultaneously), according to one embodiment. In some embodiments where multiple backoff counters (142) corresponding to each frequency segment are used when transmitting simultaneously through multiple frequency segments, the synchronized transmit controller (146) delays transmission in all multiple frequency segments until all of the multiple backoff counters (142) expire (e.g., until they reach 0). In some embodiments, when simultaneous transmission through multiple frequency segments is not synchronized (e.g., each transmit in each frequency segment starts at different times), the synchronized transmit controller (146) is configured to control the PHY processor (130) to terminate each transmit in each frequency segment simultaneously.

[0033] In one embodiment, the synchronized transmission controller (146) is implemented by a processor that executes machine-readable instructions stored in memory, wherein the machine-readable instructions cause the processor to perform operations described in more detail below. In another embodiment, the synchronized transmission controller (146) additionally or alternatively includes a hardware circuit configured to perform operations described in more detail below. In some embodiments, the hardware circuit includes one or more hardware state machines configured to perform operations described in more detail below.

[0034] In other embodiments, the backoff controller (140) and / or the synchronized transmission controller (146) are omitted from the AP (114).

[0035] The WLAN (110) also includes a plurality of client stations (154). Although three client stations (154) are shown in FIG. 1, the WLAN (110) may include other suitable numbers of client stations (154) (e.g., 1, 2, 4, 5, 6, etc.) in various embodiments. A client station (154-1) includes a host processor (158) coupled to a wireless network interface device (162). The wireless network interface device (162) includes one or more MAC processors (166) (referred to as "MAC processor (166)" in this specification for brevity) and one or more PHY processors (170) (referred to as "PHY processor (170)" in this specification for brevity). The PHY processor (170) includes a plurality of transceivers (174), and the transceivers (174) are coupled to a plurality of antennas (178). Although three transceivers (174) and three antennas (178) are illustrated in FIG. 1, the client station (154-1) includes other suitable numbers of transceivers (174) and antennas (178) (e.g., 1, 2, 4, 5, etc.) in other embodiments. In some embodiments, the client station (154-1) includes a greater number of antennas (178) than transceivers (174), and antenna switching techniques are used.

[0036] In one embodiment, the wireless network interface device (162) is configured to operate within a single RF band at a given time. In another embodiment, the wireless network interface device (162) is configured to operate within two or more RF bands simultaneously or at different times. For example, in one embodiment, the wireless network interface device (162) includes a plurality of PHY processors (170), each of which corresponds to a respective RF band. In another embodiment, the wireless network interface device (162) includes a single PHY processor (170), each of which includes a transceiver (174) that corresponds to a respective RF band. In one embodiment, the wireless network interface device (162) includes a plurality of MAC processors (166), each of which corresponds to a respective RF band. In another embodiment, the wireless network interface device (162) includes a single MAC processor (166) that corresponds to a plurality of RF bands.

[0037] The wireless network interface device (162) is implemented using one or more ICs configured to operate as described below. For example, the MAC processor (166) may be implemented on at least the first IC, and the PHY processor (170) may be implemented on at least the second IC. The first IC and the second IC may be packaged together within a single IC package to form a modular device, or the first IC and the second IC may be combined together on a single printed board, for example, in various embodiments. As another example, at least a portion of the MAC processor (166) and at least a portion of the PHY processor (170) may be implemented on a single IC. For example, the wireless network interface device (162) may be implemented using an SoC, wherein the SoC includes at least a portion of the MAC processor (166) and at least a portion of the PHY processor (170).

[0038] In one embodiment, the host processor (158) includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as RAM, ROM, flash memory, etc. In one embodiment, the host processor (158) may be implemented at least partially on a first IC, and the network device (162) may be implemented at least partially on a second IC. As another example, at least part of the host processor (158) and the wireless network interface device (162) may be implemented on a single IC.

[0039] In various embodiments, the MAC processor (166) and PHY processor (170) of the client station (154-1) are configured to generate data units according to a WLAN communication protocol or other suitable communication protocol and to process the received data units. For example, the MAC processor (166) may be configured to implement MAC layer functions including MAC layer functions of the WLAN communication protocol, and the PHY processor (170) may be configured to implement PHY functions including PHY functions of the WLAN communication protocol. The MAC processor (166) may be configured to generate MAC layer data units, such as MSDUs, MPDUs, etc., and to provide the MAC layer data units to the PHY processor (170). Additionally, in some embodiments, the MAC processor (166) is configured to select communication links to which the MAC layer data units are to be transmitted and to control the PHY processor (170) so that the MAC layer data units are transmitted on the selected communication links. Additionally, in some embodiments, the MAC processor (166) is configured to determine when each communication link is idle and available for transmission, and to control the PHY processor (170) so that MAC layer data units are transmitted when each communication link is idle. Additionally, in some embodiments, the MAC processor (166) is configured to control when parts of the wireless network interface device (162) are in a sleep state or a wake state to conserve power, for example. For example, according to some embodiments, the MAC processor (166) is configured to negotiate a schedule with the AP (114) regarding when the client station (154-1) is allowed to be in a sleep state and when the client station (154-1) must be in a wake state and be able to transmit to or receive from the AP (114).

[0040] A PHY processor (170) may be configured to receive MAC layer data units from a MAC processor (166) and encapsulate the MAC layer data units for transmission through antennas (178) to generate PHY data units such as PPDUs. Similarly, a PHY processor (170) may be configured to receive PHY data units received through antennas (178) and extract MAC layer data units encapsulated within the PHY data units. The PHY processor (170) may provide the extracted MAC layer data units to a MAC processor (166) that processes MAC layer data units.

[0041] According to one embodiment, the PHY processor (170) is configured to downconvert one or more RF signals received through one or more antennas (178) into one or more baseband analog signals, and to convert the analog baseband signal(s) into one or more digital baseband signals. The PHY processor (170) is further configured to process one or more digital baseband signals to demodulate one or more digital baseband signals and generate a PPDU. The PHY processor (170) includes amplifiers (e.g., LNA, power amplifier, etc.), an RF downconverter, an RF upconverter, a plurality of filters, one or more ADCs, one or more DACs, one or more DFT calculators (e.g., FFT calculator), one or more IDFT calculators (e.g., IFFT calculator), one or more modulators, one or more demodulators, etc.

[0042] The PHY processor (170) is configured to generate one or more RF signals provided to one or more antennas (178). The PHY processor (170) is also configured to receive one or more RF signals from one or more antennas (178).

[0043] According to some embodiments, the MAC processor (166) is configured to control the PHY processor (170) to generate one or more RF signals by providing, for example, one or more MAC layer data units (e.g., MPDUs) to the PHY processor (170) and optionally providing one or more control signals to the PHY processor (170). In one embodiment, the MAC processor (166) includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as RAM, ROM, flash memory, etc. In one embodiment, the MAC processor (166) includes a hardware state machine.

[0044] According to some embodiments, the MAC processor (166) includes or implements a backoff controller (190) identical or similar to the backoff controller (140). The backoff controller (190) includes one or more backoff counters (sometimes referred to as timers) (192). While the backoff controller (190) determines that the channel medium is idle, the backoff controller (190) controls the backoff counter (192) to decrement. Meanwhile, when the backoff controller (190) determines that the communication medium is in use, the backoff controller (190) pauses the backoff counter (192) and does not resume decrement of the backoff counter (192) until the communication medium is subsequently determined to be idle. Generally, when the backoff counter (192) reaches 0 and the communication medium is still idle, the backoff controller (190) determines that the communication device is free to transmit. Meanwhile, when the backoff counter (192) reaches 0 and the communication medium is busy, the backoff controller (190) resets the backoff counter (192), and the process is repeated.

[0045] In some embodiments, when the communication channel includes a plurality of frequency segments, a plurality of backoff counters (192) are maintained for the plurality of frequency segments in at least some scenarios. In some embodiments, when the communication channel includes a plurality of frequency segments, a single backoff counter (192) is maintained for one of the plurality of frequency segments in at least some scenarios.

[0046] In various embodiments, the backoff controller (190) performs various operations related to the operation of one or more backoff counters (192), which are described in more detail below, such as: i) determining whether to use a plurality of backoff counters (192) corresponding to each frequency segment when transmitting simultaneously through a plurality of frequency segments; ii) selecting one frequency segment corresponding to the single backoff counter (192) when a single backoff counter (192) is used when transmitting simultaneously through a plurality of frequency segments; or one or more (or none of the above).

[0047] In one embodiment, the backoff controller (190) is implemented by a processor that executes machine-readable instructions stored in memory, and the machine-readable instructions cause the processor to perform operations described in more detail below. In another embodiment, the backoff controller (190) additionally or alternatively includes a hardware circuit (e.g., one or more counters, one or more timers, one or more hardware state machines, etc.) configured to perform operations described in more detail below. In some embodiments where the hardware circuit includes one or more hardware state machines, the one or more hardware state machines are configured to perform operations described in more detail below.

[0048] Additionally or alternatively, the MAC processor (166) includes or implements a synchronized transmission controller (196) identical or similar to the synchronized transmission controller (146) according to some embodiments. According to one embodiment, the synchronized transmission controller (196) is configured to determine when multiple transmissions in multiple frequency segments are synchronized (e.g., multiple transmissions start simultaneously and optionally end simultaneously). In some embodiments where multiple backoff counters (192) corresponding to each frequency segment are used when transmitting simultaneously through multiple frequency segments, the synchronized transmission controller (196) delays transmission in all multiple frequency segments until all of the multiple backoff counters (192) expire (e.g., until they reach 0). In some embodiments, when simultaneous transmission through multiple frequency segments is not synchronized (e.g., each transmission in each frequency segment starts at different times), the synchronized transmission controller (196) is configured to control the PHY processor (170) to terminate each transmission in each frequency segment simultaneously.

[0049] In one embodiment, the synchronized transmission controller (196) is implemented by a processor that executes machine-readable instructions stored in memory, and the machine-readable instructions cause the processor to perform operations described in more detail below. In another embodiment, the synchronized transmission controller (196) additionally or alternatively includes a hardware circuit configured to perform operations described in more detail below. In some embodiments, the hardware circuit includes one or more hardware state machines configured to perform operations described in more detail below.

[0050] In one embodiment, each of the client stations (154-2 and 154-3) has the same or similar structure as client station (154-1). In one embodiment, one or more of the client stations (154-2 and 154-3) have a suitable structure different from client station (154-1). Each of the client stations (154-2 and 154-3) has the same or different number of transceivers and antennas. For example, each of the client station (154-2) and / or client station (154-3) has only two transceivers and two antennas (not shown) according to one embodiment.

[0051] FIG. 2a is a diagram of an exemplary operating channel (200) used in the communication system (110) of FIG. 1 according to one embodiment. The operating channel (200) includes a plurality of sub-channels (204) in a first frequency segment (208) and a plurality of sub-channels (212) in a second frequency segment (216). The operating channel (200) spans the entire bandwidth (220). In one embodiment, the first segment (208) and the second segment (216) are within the same radio frequency (RF) band.

[0052] In other embodiments, the first segment (208) and the second segment (216) are in different RF bands. The Federal Communications Commission (FCC) now allows wireless local area networks (WLANs) to operate in multiple RF bands, for example, the 2.4 GHz band (approximately 2.4 to 2.5 GHz) and the 5 GHz band (approximately 5.170 to 5.835 GHz). Recently, the FCC proposed that WLANs could also operate in the 6 GHz band (5.925 to 7.125 GHz). Regulatory bodies in other countries / regions also allow WLAN operation in the 2.4 GHz and 5 GHz bands and are considering allowing WLAN operation in the 6 GHz band. Future WLAN protocols currently under development may allow multi-band operation in which WLANs can use spectrum in multiple RF bands simultaneously.

[0053] In some embodiments, the first frequency segment (208) is used as a first communication link and the second frequency segment (216) is used as a second communication link, and the first communication link and the second communication link are used for simultaneous transmissions.

[0054] In one embodiment, each of the sub-channels (204 / 212) spans 20 MHz. Thus, as shown in FIG. 2a, the first segment (208) spans 160 MHz and the second segment (216) spans 80 MHz. In other embodiments, the first frequency segment (208) includes other suitable numbers of sub-channels (204) (e.g., 1, 2, 4, etc.) and spans other suitable bandwidths such as 20 MHz, 40 MHz, 80 MHz, etc., and / or the second frequency segment (216) includes other suitable numbers of sub-channels (212) (e.g., 1, 2, 8, etc.) and spans other suitable bandwidths such as 20 MHz, 40 MHz, 160 MHz, etc.

[0055] One subchannel (204-1) within the first frequency segment (208) is designated as the primary subchannel, and other subchannels (204 / 212) are designated as secondary subchannels. Control and / or management frames are transmitted on the primary subchannel (204-1) according to some embodiments. In some embodiments, the primary subchannel must be idle so that any of the subchannels (204 / 212) can be used for transmission. In some embodiments, the subchannel (212) in the second frequency segment (216) is also designated as the primary subchannel (not shown). In some embodiments where the second frequency segment (216) also includes the primary subchannel, control and / or management frames are additionally or alternatively transmitted on the primary subchannel of the second frequency segment (216) in at least some scenarios. In other embodiments, control and / or management frames are transmitted only on the primary sub-channel (204-1) of the first frequency segment (208).

[0056] According to some embodiments, in some embodiments where the second frequency segment (216) also includes a primary sub-channel, the primary sub-channel (204-1) of the first frequency segment (208) must be idle so that any of the sub-channels (204) are used for transmission, and the primary sub-channel of the second frequency segment (216) must be idle so that any of the sub-channels (212) are used for transmission. In other embodiments, according to some embodiments, one or more of the secondary sub-channels (204) may be used for transmission even when the primary sub-channel (204-1) is not idle, and / or one or more of the secondary sub-channels (212) may be used for transmission even when the primary sub-channel of the second frequency segment (216) is not idle.

[0057] In other embodiments, no sub-channel (212) in the second segment (216) is designated as a primary sub-channel.

[0058] In one embodiment, a backoff counter (142 / 192) (Fig. 1) corresponds to a primary sub-channel of an operating channel (200), for example, the backoff counter (142 / 192) is decremented when the primary sub-channel is idle, and the backoff counter (142 / 192) is paused when the primary sub-channel is in use. In one embodiment, each backoff counter (142 / 192) (Fig. 1) corresponds to each primary sub-channel of an operating channel (200), for example, each backoff counter (142 / 192) is decremented when each primary sub-channel is idle, and each backoff counter (142 / 192) is paused when each primary sub-channel is in use.

[0059] FIG. 2b is a drawing of another exemplary operating channel (250) used in the communication system (110) of FIG. 1 according to another embodiment. The operating channel (250) is similar to the exemplary operating channel (200) of FIG. 2a, and elements of the same number are not described in detail for brevity. In the exemplary operating channel (250), the first frequency segment (208) and the second frequency segment (216) are separated by a gap (254) in frequency. In some embodiments, the first frequency segment (208) and the second frequency segment (216) are in the same RF band. In other embodiments, the first frequency segment (208) and the second frequency segment (216) are in different RF bands.

[0060] In one embodiment, a backoff counter (142 / 192) (Fig. 1) corresponds to a primary sub-channel of an operating channel (250), for example, the backoff counter (142 / 192) is decremented when the primary sub-channel is idle, and the backoff counter (142 / 192) is paused when the primary sub-channel is in use. In one embodiment, each backoff counter (142 / 192) (Fig. 1) corresponds to a primary sub-channel of an operating channel (250), for example, each backoff counter (142 / 192) is decremented when each primary sub-channel is idle, and each backoff counter (142 / 192) is paused when each primary sub-channel is in use.

[0061] Now, referring to FIGS. 2a and 2b, one or more of the sub-channels (204 / 212) are "punctured" (not shown in FIGS. 2a and 2b), and according to some embodiments, for example, nothing is transmitted within the "punctured" sub-channels.

[0062] Although the exemplary operating channels (200 and 250) of FIG. 2a and 2b are illustrated as comprising two frequency segments (208 / 216), other suitable operating channels may comprise three or more frequency segments (e.g., comprising a third frequency segment, comprising a third frequency segment and a fourth frequency segment, etc.). In some embodiments, the third frequency segment is separated from the second frequency segment (216) by a frequency gap in which nothing is transmitted, similar to a gap (254). In some embodiments, the third frequency segment is contiguous with the second frequency segment (216) at a frequency.

[0063] In some embodiments, each frequency segment as illustrated in FIGS. 2a-2b is associated with different MAC addresses. For example, in embodiments where each frequency segment is used as a communication link, each communication link corresponds to a different MAC address.

[0064] FIG. 3 is a drawing of an exemplary network interface device (300) configured for simultaneous communication through a plurality of communication links in each frequency segment according to one embodiment. The network interface device (300) is an embodiment of the network interface device (122) of the AP (114) of the drawing. The network interface device (300) is an embodiment of the network interface device (162) of the client station (154-1) of FIG. 1. In other embodiments, the network interface device (122) and / or the network interface device (162) have a suitable structure different from the network interface device (300). Additionally, in some embodiments, the network interface device (300) is used in a suitable communication device different from the communication devices of FIG. 1, and / or in a suitable wireless network different from the wireless network of FIG. 1.

[0065] In the illustrated embodiment, the network interface device (300) is configured for simultaneous communication through a first communication link in a first frequency segment and a second communication link in a second frequency segment.

[0066] The network interface device (300) includes a MAC processor (304) coupled to PHY processors (308). The MAC processor (304) exchanges frames (or PSDUs) with the PHY processors (308).

[0067] In an embodiment, the MAC processor (304) corresponds to the MAC processor (126) of FIG. 1. In another embodiment, the MAC processor (304) corresponds to the MAC processor (166) of FIG. 1. In one embodiment, the PHY processors (308) correspond to one or more PHY processors (130) of FIG. 1. In another embodiment, the PHY processors (308) correspond to one or more PHY processors (170) of FIG. 1.

[0068] The MAC processor (304) includes common MAC logic (312) and link-specific (LS) MAC logic (316). The common MAC logic (312) generally implements MAC layer functions common to multiple communication links. For example, the common MAC logic (312) is configured to encapsulate data into MAC layer data units, such as MSDUs, MPDUs, aggregated MPDUs (A-MPDUs), etc., for transmission over multiple communication links in response to receiving data to be forwarded to another communication device within the WLAN (e.g., from a host processor (not shown), from a wired communication link (not shown), etc.), and to decapsulate data from MSDUs, MPDUs, A-MPDUs, etc. received over multiple communication links. Additionally, in some embodiments, the common MAC logic (312) is configured to select the communication links over which the MAC layer data units are to be transmitted.

[0069] Each LS MAC logic (316) generally implements MAC layer functions specific to the specific communication link to which the LS MAC logic (316) corresponds. For example, in some embodiments, the LS MAC logic (316a) is configured to determine when the first communication link is idle and available for transmission, and the LS MAC logic (316b) is configured to determine when the second communication link is idle and available for transmission. In some embodiments, each LS MAC logic (316) is associated with a respective network address (e.g., MAC address), that is, the LS MAC logic (316a) is associated with a first network address (e.g., first MAC address), and the LS MAC logic (316b) is associated with a second network address (e.g., second MAC address) that is different from the first network address.

[0070] In some embodiments, the common MAC logic (312) implements the backoff controller (140 / 190) discussed above with reference to FIG. 1. In some embodiments, the common MAC logic (312) additionally or alternatively implements the synchronized transmit controller (196) discussed above with reference to FIG. 1. In some embodiments, some or all of the backoff controllers (140 / 190) are implemented as respective link-specific backoff controllers (140 / 190) in each LS MAC logic (316).

[0071] A PHY processor (308a) includes a baseband signal processor (320a) corresponding to a first communication link, and a PHY processor (308b) includes a baseband signal processor (320b) corresponding to a second communication link. A PHY processor (308a) also includes a first RF radio (radio-1) (328a) corresponding to a first communication link, and a PHY processor (308b) includes a second RF radio (radio-2) (328b) corresponding to a second communication link. A baseband signal processor (320a) is coupled to the first RF radio (328a), and a baseband signal processor (320b) is coupled to the second RF radio (328b). In one embodiment, the RF radio (328a) and the RF radio (328b) correspond to the transceivers (134) of FIG. 1. In another embodiment, RF radio (328a) and RF radio (328b) correspond to the transceivers (174) of FIG. 1. In one embodiment, RF radio (328a) is configured to operate on a first RF band, and RF radio (328b) is configured to operate on a second RF band. In another embodiment, RF radio (328a) and RF radio (328b) are both configured to operate on the same RF band.

[0072] In one embodiment, baseband signal processors (320) are configured to receive frames (or PSDUs) from a MAC processor (304), encapsulate the frames (or PSDUs) into respective packets, and generate respective baseband signals corresponding to each packet.

[0073] A baseband signal processor (320a) provides each baseband signal generated by the baseband signal processor (320a) to Radio-1 (328a). A baseband signal processor (320b) provides each baseband signal generated by the baseband signal processor (320b) to Radio-1 (328b). Radio-1 (328a) and Radio-2 (328b) each generate RF signals by upconverting their respective baseband signals for transmission through a first communication link and a second communication link, respectively. Radio-1 (328a) transmits the first RF signal through the first frequency segment, and Radio-2 (328b) transmits the second RF signal through the second frequency segment.

[0074] Radio-1 (328a) and Radio-2 (328b) are also configured to receive RF signals through a first communication link and a second communication link, respectively. Radio-1 (328a) and Radio-2 (328b) generate baseband signals corresponding to each of the received signals. Each generated baseband signal is provided to each baseband signal processor (320a, 320b). Each baseband signal processor (320a, 320b) generates a PSDU corresponding to the received signal and provides it to a MAC processor (304). In one embodiment, the MAC processor (304) processes the PSDUs received from the baseband signal processors (320a and 320b).

[0075] In some embodiments, the common MAC logic (312) and / or LS MAC logic (316) are at least partially implemented by a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as RAM, ROM, flash memory, etc. In other embodiments, the common MAC logic (312) and / or LS MAC logic (316) are additionally or alternatively implemented by hardware logic, such as one or more hardware state machines.

[0076] In some embodiments, baseband signal processors (320) are at least partially implemented by a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as RAM, ROM, flash memory, etc. In other embodiments, the baseband signal processor (320) is additionally or alternatively implemented by one or more hardware logics, such as a hardware state machine, a hardware calculator (e.g., an FFT calculator, an IFFT calculator), a hardware modulator, etc.

[0077] The exemplary network interface (300) illustrated in FIG. 3 includes a single MAC processor (304), but other suitable network interface devices include multiple MAC processors, each of which corresponds to each of the communication links in some embodiments. The exemplary network interface (300) illustrated in FIG. 3 includes multiple PHY processors (308), but other suitable network interface devices include a single PHY processor having multiple RF radios corresponding to each of the communication links in some embodiments. In some embodiments, the single PHY processor includes multiple baseband processors (320), whereas in other embodiments, the single PHY processor includes a single baseband processor configured to generate multiple baseband signals corresponding to each of the communication links and to process multiple baseband signals received from multiple RF radios.

[0078] In some wireless networks, one or more communication devices within the wireless network may not be able to transmit and receive simultaneously over different frequency segments due to, for example, physical limitations of the communication devices, channel conditions, etc. Additionally or alternatively, the AP (114) may determine that simultaneous transmission and reception over different frequency segments in the WLAN is not allowed due to, for example, physical limitations of one or more communication devices in the WLAN, channel conditions, etc.

[0079] According to one embodiment, the client station (154) notifies the AP (114) whether the client station (154) can transmit and receive simultaneously through different frequency segments. For example, during the setup phase of an operating channel having multiple frequency links (sometimes referred to as "multi-ink association"), the client station (154), according to one embodiment, transmits to the AP (114) a frame (e.g., a management frame, a control frame, an action frame, etc.) containing information indicating whether the client station (154) can transmit and receive simultaneously. As another example, when joining or attempting to join a managed WLAN (sometimes referred to as "multi-ink association"), the client station (154), according to one embodiment, transmits to the AP (114) a frame (e.g., an association request frame, a re-association request frame, a probe request frame, etc.) containing information indicating whether the client station (154) can transmit and receive simultaneously.

[0080] According to one embodiment, the AP (114) notifies one or more client stations (154) whether simultaneous transmission and reception over different frequency segments are allowed in the WLAN (110). For example, during the setup phase of an operating channel having multiple frequency links (sometimes referred to as "multi-ink association"), the AP (114), according to one embodiment, transmits a frame (e.g., a management frame, a control frame, an action frame, etc.) containing information indicating whether simultaneous transmission and reception over different frequency segments are allowed in the WLAN (110) to one or more client stations (154). As another example, when a client station (154) attempts to join a managed WLAN (110) (sometimes referred to as "multi-ink association"), the AP (114), according to one embodiment, transmits to the client station (154) a frame (e.g., association response frame, re-association response frame, probe response frame, etc.) containing information indicating whether simultaneous transmission and reception over different frequency segments are allowed in the WLAN (110). As another example, according to one embodiment, the AP (114) periodically transmits a beacon frame containing information indicating whether simultaneous transmission and reception over different frequency segments are allowed in the WLAN (110). In another example, if the AP (114) decides to switch to not allowing simultaneous transmission and reception through different frequency segments, or vice versa, the AP (114) transmits a frame (e.g., a management frame, a control frame, an action frame, etc.) containing information indicating whether simultaneous transmission and reception through different frequency segments is allowed in the WLAN (110), according to one embodiment.

[0081] In some embodiments, when simultaneous transmission / reception in multiple frequency segments is not allowed (e.g., i) when a first communication device does not allow simultaneous transmission / reception in multiple frequency segments, ii) when a second communication device does not allow simultaneous transmission / reception in multiple frequency segments, iii) when simultaneous transmission / reception in multiple frequency segments is not allowed in a WLAN, etc.), and when the first communication device is transmitting asynchronous transmissions in multiple frequency segments (e.g., when multiple transmissions in multiple frequency segments are not started simultaneously), the first communication device terminates the asynchronous transmissions in multiple frequency segments simultaneously. In some embodiments, when one or more of the unsynchronized transmissions in multiple frequency segments prompt another communication device to transmit an acknowledgment, terminating the unsynchronized transmissions simultaneously helps to avoid one communication device transmitting in one frequency segment while another communication is transmitting an acknowledgment in another frequency segment.

[0082] FIG. 4 is a diagram of an example of unsynchronized transmissions (400) in a plurality of frequency segments corresponding to a plurality of communication links according to one embodiment. A first communication device transmits a first packet (404) in a first frequency segment corresponding to a first communication link and simultaneously transmits a second packet (408) in a second frequency segment corresponding to a second communication link. The transmission of the first packet (404) begins before the transmission of the second packet (408) begins, and thus the transmission of the first packet (404) and the transmission of the second packet (408) begin at different times.

[0083] A first communication device receives a first acknowledgment (412) (e.g., an acknowledgment frame included in the packet, a block acknowledgment (BA) frame, etc.) in a first frequency segment in response to a first packet (404). In one embodiment, the communication device receiving the packet (404) begins transmitting the first acknowledgment (412) in a defined time period after the end of receiving the packet (404). In one embodiment, the defined time period is a short interframe space (SIFS) defined by the IEEE 802.11 standard. In other embodiments, the defined time period is another appropriate time duration.

[0084] Similarly, the first communication device receives a second acknowledgment (416) (e.g., an acknowledgment frame, a BA frame, etc. included in the packet) in a second frequency segment in response to the second packet (408). In one embodiment, the communication device receiving the second packet (408) begins transmitting the second acknowledgment (416) in a defined time period after the end of receiving the second packet (408). In one embodiment, the defined time period is SIFS as defined by the IEEE 802.11 standard. In other embodiments, the defined time period is another appropriate time duration.

[0085] To avoid the transmission of the second packet (408) occurring simultaneously with the reception of the acknowledgment (412), the first communication device includes padding information (420) in the packet (404) so ​​that the end of the transmission of the packet (404) occurs simultaneously with the end of the transmission of the packet (408). In the exemplary example of FIG. 4, if the padding information (420) were not included in the packet (404), the reception of the acknowledgment (412) would occur earlier and would overlap with the transmission of the packet (408). However, by including the padding information (420), the start of the reception of the acknowledgment (412) is delayed until after the end of the transmission of the second packet (408).

[0086] In some embodiments, if multiple transmissions in each frequency segment do not prompt acknowledgments to start a defined time period (e.g., SIFS or other appropriate time duration) after the end of the transmission, the transmissions are allowed to end at different times, and thus padding such as padding (420) is not added to the packet. In other embodiments, even if multiple transmissions in each frequency segment do not prompt acknowledgments to start a defined time period (e.g., SIFS or other appropriate time duration) after the end of the transmission, the transmissions are required to end simultaneously.

[0087] In some embodiments, if simultaneous transmission and reception in each frequency segment are allowed, the transmissions are allowed to terminate at different times, and thus padding such as padding (420) is not added to the packet. In other embodiments, even if simultaneous transmission and reception in each frequency segment are allowed, padding such as padding (420) is added to the packet so that the transmissions terminate simultaneously.

[0088] FIG. 4 illustrates an example of transmitting two packets simultaneously in two frequency segments, but in other embodiments, three or more packets are transmitted simultaneously in three or more respective frequency segments. In some embodiments, padding (similar to packet (404)) is added to two or more packets so that the transmission of three or all of the packets is terminated simultaneously.

[0089] FIG. 5 is a flowchart of an exemplary method (500) for transmitting simultaneously over a plurality of frequency segments according to one embodiment. In some embodiments, the plurality of frequency segments correspond to respective communication links. In some embodiments, an AP (114) and / or a client station (154) is configured to implement the method (500), and FIG. 5 is described with reference to FIG. 1 for illustrative purposes only. In other embodiments, the method (500) is implemented by other suitable communication devices.

[0090] In block (504), the communication device determines that simultaneous transmission and reception over multiple frequency segments is not allowed (e.g., determined by the network interface (122), determined by the MAC processor (126), determined by the synchronized transmission controller (146), determined by the network interface (162), determined by the MAC processor (166), determined by the synchronized transmission controller (196), etc.). For example, determining that simultaneous transmission and reception are not allowed in block (504) includes, depending on various embodiments, one or more of: i) determining that a communication device implementing the method (400) is not allowed to transmit and receive simultaneously over multiple frequency segments; ii) determining that another communication device to transmit as part of the method (400) is not allowed to transmit and receive simultaneously over multiple frequency segments; and iii) determining that simultaneous transmission and reception over multiple frequency segments is not allowed in the WLAN where the communication device operates (or none of the above).

[0091] In some embodiments, in block (504), determining that simultaneous transmission and reception through multiple frequency segments is not allowed includes determining that a communication device is not allowed to transmit and receive simultaneously through multiple frequency segments. In some embodiments, in block (504), determining that simultaneous transmission and reception through multiple frequency segments is not allowed includes receiving from another communication device a packet containing information indicating that another communication device is not allowed to transmit and receive simultaneously through multiple frequency segments, and the communication device will transmit to the other communication device as part of the method (400). In some embodiments, in block (504), determining that simultaneous transmission and reception through multiple frequency segments is not allowed includes receiving from the AP a packet containing information indicating that simultaneous transmission and reception through multiple frequency segments is not allowed in a WLAN managed by the AP.

[0092] In block (508), the communication device transmits a first packet in a first frequency segment starting at a first time (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). In block (512), the communication device transmits a second packet in a second frequency segment starting at a second time different from the first time (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). The transmission of the second packet in block (512) overlaps temporally with the transmission of the first packet in block (508).

[0093] In response to the determination in block (504) that simultaneous transmission and reception through multiple frequency segments is not allowed in block (516), the communication device includes padding in the first packet so that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet (e.g., including a network interface (122), including a PHY processor (130), including a network interface (162), including a PHY processor (170), etc.). In some embodiments, a MAC processor (e.g., MAC processor (126), MAC processor (166), etc.) instructs a PHY processor (e.g., PHY processor (130), PHY processor (170), etc.) to include padding in the first packet so that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet, and the PHY processor (e.g., PHY processor (130), PHY processor (170), etc.) determines the amount of padding to include in the first packet so that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet.

[0094] In some embodiments, if the communication device determines that simultaneous transmission and reception through multiple frequency segments in block (504) is not allowed, the communication device does not include padding in the first packet so that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet (e.g., not including the network interface (122), not including the PHY processor (130), not including the network interface (162), not including the PHY processor (170), etc.). In some embodiments, the MAC processor (e.g., MAC processor (126), MAC processor (166), etc.) instructs the PHY processor (e.g., PHY processor (130), PHY processor (170), etc.) not to include padding in the first packet so that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet. In some embodiments, nevertheless, padding is added for purposes other than ensuring that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet, such as to ensure that the modulated information terminates on the OFDM symbol boundary, to add packet extensions to allow the receiving device more time to generate a response to the packet, etc.

[0095] In some embodiments, a communication device in a WLAN transmits simultaneously and synchronously across multiple frequency segments, for example, multiple transmissions across multiple frequency segments start simultaneously. In some embodiments, a communication device in a WLAN is configured to perform both i) transmit simultaneously across multiple frequency segments—where multiple transmissions across multiple frequency segments are required to start simultaneously—and ii) transmit simultaneously and synchronously across multiple frequency segments, for example, where multiple transmissions across multiple frequency segments are required to start simultaneously. For example, in some embodiments, at some times and / or in some situations, simultaneous transmissions across multiple frequency segments are required to start simultaneously, whereas at other times and / or in other situations, simultaneous transmissions across multiple frequency segments are allowed to start at different times. As an example, according to some embodiments, whether simultaneous transmissions across multiple frequency segments are required to start simultaneously depends on the frequency distance between the multiple frequency segments. For example, in an exemplary embodiment, when the first frequency segment is in the 2.4 GHz band and the second frequency segment is in the 6 GHz band, simultaneous transmissions in multiple frequency segments are allowed to start at different times. Meanwhile, as another example, according to another exemplary embodiment, when the first frequency segment is in the 5 GHz band and the second frequency segment is in the 6 GHz band, or when the first and second frequency segments are in the same RF band, simultaneous transmissions in multiple frequency segments are required to start simultaneously.

[0096] In some embodiments involving simultaneous and synchronous transmissions in multiple frequency segments, the communication device performs each backoff operation (using multiple backoff counters) in multiple frequency segments (e.g., each backoff operation in each of the multiple frequency segments), and initiates simultaneous and synchronous transmissions in multiple frequency segments in response to all backoff counters expiring (e.g., all backoff counters reaching 0).

[0097] FIG. 6 is a flowchart of an exemplary method (600) for transmitting simultaneously on a plurality of frequency segments starting simultaneously, according to another embodiment. In some embodiments, the plurality of frequency segments correspond to respective communication links. In some embodiments, an AP (114) and / or a client station (154) is configured to implement the method (600), and FIG. 6 is described with reference to FIG. 1 only for illustrative purposes. In other embodiments, the method (500) is implemented by other suitable communication devices.

[0098] In block (604), the communication device determines whether a number of backoff counters (e.g., backoff counters (142), backoff counters (192), etc.) corresponding to a number of frequency segments of the operating channel have expired (e.g., reached 0) (e.g., determined by the network interface (122), determined by the MAC processor (126), determined by the backoff controller (140), determined by the network interface (162), determined by the MAC processor (166), determined by the backoff controller (190), etc.). For example, in one embodiment, the communication device maintains a respective backoff counter (142 / 192) for each frequency segment (e.g., maintained by the network interface (122), maintained by the MAC processor (126), maintained by the backoff controller (140), maintained by the network interface (162), maintained by the MAC processor (166), maintained by the backoff controller (190), etc.). In one embodiment, each backoff counter (142 / 192) corresponds to each sub-channel within each frequency segment, and the backoff counter (142 / 192) is decremented when each sub-channel is determined to be idle and is stopped when each sub-channel is determined to be busy. In one embodiment, each backoff counter (142 / 192) corresponds to each primary sub-channel within each frequency segment, and the backoff counter (142 / 192) is decremented when each primary sub-channel is determined to be idle and is stopped when each primary sub-channel is determined to be busy.

[0099] In response to a determination in block (604) that not all of the multiple backoff counters have expired (e.g., one or more of the backoff counters have not expired), the communication device waits until all of the multiple backoff counters have expired (e.g., the network interface (122) waits, the MAC processor (126) waits, the backoff controller (140) waits, the network interface (162) waits, the MAC processor (166) waits, the backoff controller (190) waits, etc.).

[0100] In some embodiments, when one backoff counter expires but one or more other backoff counters do not expire, the method (600) includes the step of waiting until all backoff counters expire.

[0101] In block (604), in response to the determination that all of the multiple backoff counters have expired, the flow proceeds to block (608). In block (608), the communication device determines whether any secondary sub-channels in the operating channel are idle for a time period determined prior to the start of transmission in the operating channel. In one embodiment, the defined time period is an appropriate time duration, such as the point coordination function (PCF) PIFS (PCF interframe space) defined by the IEEE 802.11 standard. In other embodiments, the defined time period is another appropriate time duration, such as the distributed coordination function (DCF) DIFS (DCF interframe space) defined by the IEEE 802.11 standard, SIFS defined by the IEEE 802.11 standard, or other appropriate time periods.

[0102] In block (608), in response to a determination that not all secondary sub-channels within the operating channel are idle for a time period determined prior to the start of transmission in the operating channel (e.g., that one or more of the secondary sub-channels are in use), the flow proceeds to block (612). In block (612), transmission in the operating channel is not performed. In some embodiments, with respect to block (612), a number of backoff counters are reset, and flow (600) is repeated. In other embodiments, transmission is performed on i) a number of primary sub-channels corresponding to a number of backoff counters and ii) one or more secondary sub-channels that are idle (if any).

[0103] Meanwhile, in block (608), in response to a determination that all secondary sub-channels in the operating channel are idle for a time period determined prior to the start of transmission in the operating channel (e.g., that one or more of the secondary sub-channels are in use), the flow proceeds to block (616). In block (616), transmission in the operating channel is performed, including simultaneous transmission in multiple frequency segments that start simultaneously.

[0104] FIG. 7 is a diagram of an exemplary example of simultaneous transmission in multiple frequency segments starting simultaneously, according to one embodiment. In some embodiments, transmission (700) is performed according to the method (600) of FIG. 6. In other embodiments, transmission (700) is performed according to another suitable method for simultaneous transmission in multiple frequency segments starting simultaneously.

[0105] The transmission (700) is within an operating channel comprising a first frequency segment and a second frequency segment. In some embodiments, the first frequency segment corresponds to a first communication link, and the second frequency segment corresponds to a second communication link.

[0106] The communication device performs a first backoff procedure (704) in relation to the first frequency segment (e.g., the network interface (122) performs, the MAC processor (126) performs, the backoff controller (140) performs, the network interface (162) performs, the MAC processor (166) performs, the backoff controller (190) performs, etc.), and performs a second backoff procedure (708) in relation to the second frequency segment (e.g., the network interface (122) performs, the MAC processor (126) performs, the backoff controller (140) performs, the network interface (162) performs, the MAC processor (166) performs, the backoff controller (190) performs, etc.).

[0107] In some embodiments, performing the backoff procedure (704) includes decrementing the first backoff counter when it is determined that a sub-channel in the first frequency segment is idle, and pausing the decrement of the first backoff counter when it is determined that a sub-channel in the first frequency segment is not idle (e.g., in use). In some embodiments, performing the backoff procedure (704) includes decrementing the first backoff counter when it is determined that a primary sub-channel in the first frequency segment is idle, and pausing the decrement of the first backoff counter when it is determined that a primary sub-channel in the first frequency segment is not idle (e.g., in use).

[0108] In some embodiments, performing the backoff procedure (708) includes decrementing the second backoff counter when it is determined that a sub-channel in the second frequency segment is idle, and pausing the decrement of the second backoff counter when it is determined that a sub-channel in the second frequency segment is not idle (e.g., in use). In some embodiments, performing the backoff procedure (708) includes decrementing the second backoff counter when it is determined that a primary sub-channel in the second frequency segment is idle, and pausing the decrement of the second backoff counter when it is determined that a primary sub-channel in the second frequency segment is not idle (e.g., in use).

[0109] In the exemplary transmission (700) of FIG. 7, the first backoff counter expires before the second backoff counter expires. In response to the first backoff counter expiring before the second backoff counter expires, the communication device delays transmission in the first frequency segment until the second backoff counter expires (e.g., waits for transmission). In response to the second backoff counter expiring, the communication transmits a transmission (720) comprising a first transmission (724) in the first frequency segment and a second transmission (728) in the second frequency segment (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). The first transmission (724) and the second transmission (728) begin simultaneously.

[0110] In one embodiment, the first transmission (724) includes a first PHY data unit, and the second transmission (728) includes a PHY data unit packet. In another embodiment, the first transmission (724) and the second transmission (728) correspond to a single PHY data unit spanning an operating channel.

[0111] FIG. 8 is a diagram of another exemplary example of simultaneous transmission in multiple frequency segments starting simultaneously, according to another embodiment. In some embodiments, transmission (800) is performed according to the method (600) of FIG. 6. In other embodiments, transmission (800) is performed according to another suitable method for simultaneous transmission in multiple frequency segments starting simultaneously.

[0112] The transmission (800) is within an operating channel comprising a first frequency segment and a second frequency segment. In some embodiments, the first frequency segment corresponds to a first communication link, and the second frequency segment corresponds to a second communication link.

[0113] The transmission (800) is similar to the transmission (700) of FIG. 7, and elements of the same number are not described in detail for brevity.

[0114] In response to a first backoff counter expiring before the second backoff counter expires, the communication device delays transmission (724) (e.g., waits for transmission) until the second backoff counter expires and transmits a padding signal (804). In response to the second backoff counter expiring, the communication stops transmitting the padding signal (804) and starts transmitting a transmission (720) including a first transmission (724) in a first frequency segment and a second transmission (728) in a second frequency segment (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). In one embodiment, the transmission (724) includes a PHY preamble having a training field (e.g., L-STF (legacy short training field) or other suitable training field) used by receivers, particularly for packet detection. In some embodiments, the padding signal (804) has a low cross-correlation with the training field within the PHY preamble used by receivers for packet detection, so that the probability of receivers mistaking the padding signal (804) for the start of a packet is low. Additionally or alternatively, the padding signal (804), according to some embodiments, is configured to prompt receiver devices to determine whether the subchannel(s) to which the padding signal (804) is transmitted are in use, which increases the probability that other communication devices will not attempt to transmit on the subchannel(s) corresponding to the first transmission (724) between the expiration of the first backoff counter and the expiration of the second backoff counter.

[0115] FIGS. 7 and 8 illustrate exemplary simultaneous transmissions in two frequency segments, and in other embodiments, three or more transmissions are transmitted simultaneously in three or more respective frequency segments. With reference to FIG. 8, in some embodiments, padding is transmitted in two or more frequency segments.

[0116] Now, referring to FIG. 6-8, when frame transmission fails in relation to simultaneous transmission in multiple frequency segments (e.g., when an acknowledgment of the frame is not received), according to one embodiment, the value of CW is adjusted for only one of the backoff counters (e.g., the value of CW for one or more other backoff counters remains the same) (e.g., approximately twice the upper limit of CWmax). When frame transmission in one frequency segment fails in relation to simultaneous transmission in multiple frequency segments (e.g., when an acknowledgment of the frame is not received), according to one embodiment, the value of CW is adjusted for only the backoff counter corresponding to one frequency segment (e.g., the value of CW for one or more other backoff counters remains the same) (e.g., approximately twice the upper limit of CWmax). In other embodiments, when frame transmission in one frequency segment fails in relation to simultaneous transmission in multiple frequency segments (e.g., when an acknowledgment of the frame is not received), the value of CW is adjusted for all backoff counters (e.g., approximately twice the upper limit of CWmax).

[0117] FIG. 9 is a flowchart of another exemplary method (900) for transmitting simultaneously on multiple frequency segments starting simultaneously, according to another embodiment. In some embodiments, multiple frequency segments correspond to respective communication links. In some embodiments, an AP (114) and / or a client station (154) is configured to implement the method (900), and FIG. 9 is described with reference to FIG. 1 only for illustrative purposes. In other embodiments, the method (500) is implemented by other suitable communication devices.

[0118] In block (904), the communication device determines whether a single backoff counter (e.g., backoff counter (142), backoff counter (192), etc.) corresponding to a single frequency segment of the operating channel has expired (e.g., reached 0) (e.g., whether the network interface (122) determines, the MAC processor (126) determines, the backoff controller (140) determines, the network interface (162) determines, the MAC processor (166) determines, the backoff controller (190) determines, etc.). In one embodiment, the backoff counter (142 / 192) corresponds to a sub-channel within a single frequency segment, and the backoff counter (142 / 192) is decremented when it is determined that the sub-channel is idle, and decrement is paused when it is determined that the sub-channel is busy. In one embodiment, the backoff counter (142 / 192) corresponds to a primary subchannel within a single frequency segment, and the backoff counter (142 / 192) is decremented when it is determined that the primary subchannel is idle and decremented when it is determined that the primary subchannel is in use.

[0119] In block (904), in response to the determination that a single backoff counter has not expired, the communication device waits until the single backoff counter expires (e.g., the network interface (122) waits, the MAC processor (126) waits, the backoff controller (140) waits, the network interface (162) waits, the MAC processor (166) waits, the backoff controller (190) waits, etc.).

[0120] In block (904), in response to the determination that a single backoff counter has expired, the flow proceeds to block (908). In block (908), the communication device determines whether all other sub-channels in the operating channel (e.g., sub-channels other than the primary sub-channel corresponding to the backoff counter) are idle for a determined time period prior to the start of transmission in the operating channel. In one embodiment, the defined time period is an appropriate time duration, such as PIFS defined by the IEEE 802.11 standard. In other embodiments, the defined time period is another appropriate time duration, such as DIFS defined by the IEEE 802.11 standard, SIFS defined by the IEEE 802.11 standard, or another appropriate time period.

[0121] In block (908), in response to a determination that not all other sub-channels in the operating channel are idle during a time period determined prior to the start of transmission in the operating channel (e.g., that one or more of the other sub-channels are in use), the flow proceeds to block (912). In block (912), transmission in the operating channel is not performed. In some embodiments, with respect to block (912), a single backoff counter is reset, and flow (900) is repeated. In other embodiments, transmission is performed on i) a primary sub-channel corresponding to the backoff counters and ii) one or more other sub-channels that are idle (if any).

[0122] Meanwhile, in block (908), in response to a determination that all other sub-channels in the operating channel are idle (e.g., one or more of the secondary sub-channels are in use) for a time period determined prior to the start of transmission in the operating channel, the flow proceeds to block (916). In block (916), transmission in the operating channel is performed, including simultaneous transmission in multiple frequency segments that start simultaneously.

[0123] FIG. 10 is a diagram of an exemplary example of simultaneous transmission in multiple frequency segments starting simultaneously, according to one embodiment. In some embodiments, transmission (1000) is performed according to the method (900) of FIG. 9. In other embodiments, transmission (1000) is performed according to another suitable method for simultaneous transmission in multiple frequency segments starting simultaneously.

[0124] The transmission (1000) is within an operating channel comprising a first frequency segment and a second frequency segment. In some embodiments, the first frequency segment corresponds to a first communication link, and the second frequency segment corresponds to a second communication link.

[0125] The communication device performs a backoff procedure (1004) in relation to the first frequency segment (e.g., the network interface (122) performs it, the MAC processor (126) performs it, the backoff controller (140) performs it, the network interface (162) performs it, the MAC processor (166) performs it, the backoff controller (190) performs it, etc.). In some embodiments, performing the backoff procedure (1004) includes decrementing a backoff counter when it is determined that a sub-channel within the first frequency segment is idle, and pausing the decrementing of the backoff counter when it is determined that a sub-channel within the first frequency segment is not idle (e.g., in use). In some embodiments, performing the backoff procedure (1004) includes decrementing the backoff counter when it is determined that the primary subchannel in the first frequency segment is idle, and pausing the decrement of the backoff counter when it is determined that the primary subchannel in the first frequency segment is not idle (e.g., in use).

[0126] In response to the expiration of the backoff counter, the communication transmits a transmission (1020) comprising a first transmission (1024) in a first frequency segment and a second transmission (1028) in a second frequency segment (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). The first transmission (1024) and the second transmission (1028) start simultaneously.

[0127] In an embodiment, the first transmission (1024) includes a first PHY data unit, and the second transmission (1028) includes a PHY data unit packet. In another embodiment, the first transmission (1024) and the second transmission (1028) correspond to a single PHY data unit spanning an operating channel.

[0128] In some embodiments, a backoff procedure is performed for transmissions over multiple frequency segments, and the frequency segment that starts simultaneously changes over time. For example, in some embodiments, with respect to a first transmission over multiple frequency segments, a communication device selects a frequency segment among the multiple frequency segments to perform a backoff procedure different from that used for a previous second transmission over multiple frequency segments.

[0129] FIG. 11 is a diagram of an exemplary example of a plurality of sets (1100) of simultaneous transmissions according to one embodiment. In some embodiments, each set of transmissions in the plurality of sets of transmissions (1100) is performed according to the method (900) of FIG. 9. In other embodiments, each set of transmissions in the plurality of sets of transmissions (1100) is performed according to another suitable method for simultaneous transmission in a plurality of frequency segments that start simultaneously.

[0130] Sets of transmissions (1100) are within an operating channel comprising a first frequency segment and a second frequency segment. In some embodiments, the first frequency segment corresponds to a first communication link, and the second frequency segment corresponds to a second communication link.

[0131] In relation to a first set of transmissions (1104), the communication device performs a backoff procedure (1108) in relation to a first frequency segment (e.g., performed by a network interface (122), performed by a MAC processor (126), performed by a backoff controller (140), performed by a network interface (162), performed by a MAC processor (166), performed by a backoff controller (190), etc.). In some embodiments, performing the backoff procedure (1108) includes decrementing a backoff counter when it is determined that a sub-channel within the first frequency segment is idle, and pausing the decrement of the backoff counter when it is determined that a sub-channel within the first frequency segment is not idle (e.g., in use). In some embodiments, performing the backoff procedure (1108) includes decrementing the backoff counter when it is determined that the primary subchannel in the first frequency segment is idle, and pausing the decrement of the backoff counter when it is determined that the primary subchannel in the first frequency segment is not idle (e.g., in use).

[0132] In response to the expiration of the backoff counter, the communication transmits a set of transmissions (1104) including a first transmission (1124) in a first frequency segment and a second transmission (1128) in a second frequency segment (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). The first transmission (1124) and the second transmission (1128) start simultaneously.

[0133] In one embodiment, the first transmission (1124) includes a first PHY data unit, and the second transmission (1128) includes a PHY data unit packet. In another embodiment, the first transmission (1124) and the second transmission (1128) correspond to a single PHY data unit spanning an operating channel.

[0134] In relation to a second set of transmissions (1134), the communication device performs a backoff procedure (1138) in relation to the second frequency segment (e.g., performed by the network interface (122), performed by the MAC processor (126), performed by the backoff controller (140), performed by the network interface (162), performed by the MAC processor (166), performed by the backoff controller (190), etc.). In some embodiments, performing the backoff procedure (1138) includes decrementing a backoff counter when it is determined that a sub-channel within the second frequency segment is idle, and pausing decrementing the backoff counter when it is determined that a sub-channel within the second frequency segment is not idle (e.g., in use). In some embodiments, performing the backoff procedure (1138) includes decrementing the backoff counter when it is determined that the primary subchannel in the second frequency segment is idle, and pausing the decrement of the backoff counter when it is determined that the primary subchannel in the second frequency segment is not idle (e.g., in use).

[0135] In response to the expiration of the backoff counter, the communication transmits a set of transmissions (1134) including a first transmission (1144) in a first frequency segment and a second transmission (1148) in a second frequency segment (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). The first transmission (1144) and the second transmission (1148) start simultaneously.

[0136] In one embodiment, the first transmission (1144) includes a first PHY data unit, and the second transmission (1148) includes a PHY data unit packet. In another embodiment, the first transmission (1144) and the second transmission (1148) correspond to a single PHY data unit spanning an operating channel.

[0137] In relation to the third set of transmissions (1154), the communication device performs a backoff procedure (1158) in relation to the first frequency segment (e.g., performed by the network interface (122), performed by the MAC processor (126), performed by the backoff controller (140), performed by the network interface (162), performed by the MAC processor (166), performed by the backoff controller (190), etc.). In some embodiments, performing the backoff procedure (1158) includes decrementing a backoff counter when it is determined that a sub-channel within the first frequency segment is idle, and pausing decrementing the backoff counter when it is determined that a sub-channel within the first frequency segment is not idle (e.g., in use). In some embodiments, performing the backoff procedure (1158) includes decrementing the backoff counter when it is determined that the primary subchannel in the first frequency segment is idle, and pausing the decrement of the backoff counter when it is determined that the primary subchannel in the first frequency segment is not idle (e.g., in use).

[0138] In response to the expiration of the backoff counter, the communication transmits a set of transmissions (1154) including a first transmission (1164) in a first frequency segment and a second transmission (1168) in a second frequency segment (e.g., the network interface (122) transmits, the PHY processor (130) transmits, the network interface (162) transmits, the PHY processor (170) transmits, etc.). The first transmission (1164) and the second transmission (1168) start simultaneously.

[0139] In one embodiment, the first transmission (1164) includes a first PHY data unit, and the second transmission (1168) includes a PHY data unit packet. In another embodiment, the first transmission (1164) and the second transmission (1168) correspond to a single PHY data unit spanning an operating channel.

[0140] FIGS. 10 and 11 illustrate exemplary simultaneous transmissions in two frequency segments, and in other embodiments, three or more transmissions are transmitted simultaneously in three or more respective frequency segments. With reference to FIG. 11, in some embodiments, backoff operations are performed in three or more frequency segments.

[0141] FIG. 9-11 illustrates performing a backoff operation only on a frequency segment using only one backoff counter. In some embodiments, the communication device maintains multiple backoff counters for multiple frequency segments (e.g., the network interface (122) maintains, the MAC processor (126) maintains, the backoff controller (140) maintains, the network interface (162) maintains, the MAC processor (166) maintains, the backoff controller (190) maintains, etc.), and backoff counters corresponding to other frequency segments are ignored at least when the backoff counter corresponding to one frequency segment expires. In one embodiment, when another backoff counter corresponding to another frequency segment expires, the other backoff counter is reset as discussed above. In one embodiment, when another backoff counter corresponding to another frequency segment expires, the value of CW is increased, and the other backoff counter is reset as discussed above. In one embodiment, the value of CW is increased by adding a value randomly or pseudo-randomly selected from the range [0, 1]. In another embodiment, when another backoff counter corresponding to a different frequency segment expires, the value of CW remains the same, and the other backoff counter is reset as discussed above.

[0142] Referring to FIG. 9-11, when frame transmission fails in relation to simultaneous transmission in multiple frequency segments (e.g., failure to receive an acknowledgment of the frame), according to one embodiment, the value of CW is adjusted for only one of the backoff counters (e.g., the value of CW for one or more other backoff counters remains the same) (e.g., approximately twice the upper limit of CWmax). When frame transmission in one frequency segment fails in relation to simultaneous transmission in multiple frequency segments (e.g., failure to receive an acknowledgment of the frame), according to one embodiment, the value of CW is adjusted for only the backoff counter corresponding to one frequency segment (e.g., the value of CW for one or more other backoff counters remains the same) (e.g., approximately twice the upper limit of CWmax). In other embodiments, when frame transmission in one frequency segment fails in relation to simultaneous transmission in multiple frequency segments (e.g., failure to receive an acknowledgment of the frame), the value of CW is adjusted for all backoff counters (e.g., approximately twice the upper limit of CWmax).

[0143] In the various embodiments discussed above, the communication device determines whether the subchannel is idle by comparing the energy level measured in the subchannel with a threshold. In some embodiments, the communication device additionally or alternatively determines whether the subchannel is idle by determining whether a network allocation vector (NAV) counter corresponding to the subchannel has expired (e.g., determined by the network interface (122), determined by the MAC processor (126), determined by the backoff controller (140), determined by the network interface (162), determined by the MAC processor (166), determined by the backoff controller (190), etc.). In some embodiments, the NAV counter indicates whether another communication device has captured the communication medium. For example, the NAV counter is set using duration information within a received frame, and the NAV counter is decremented by a predetermined rate. When the NAV counter expires (e.g., when it reaches 0), this indicates that another communication device is not currently in control of the communication medium.

[0144] Example 1: A method for transmitting simultaneously across a plurality of frequency segments, comprising: a step of determining in a communication device that simultaneous transmission and reception through a plurality of frequency segments is not permitted; a step of transmitting a first packet in a first frequency segment starting at a first time by the communication device; a step of transmitting a second packet in a second frequency segment starting at a second time different from the first time by the communication device, wherein the transmission of the second packet overlaps temporally with the transmission of the first packet; and a step of including padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet in response to the determination that simultaneous transmission and reception through a plurality of frequency segments is not permitted.

[0145] Example 2: The method of Example 1, wherein the step of determining that simultaneous transmission and reception through a plurality of frequency segments is not allowed comprises the step of the communication device determining that simultaneous transmission and reception through a plurality of frequency segments is not allowed.

[0146] Example 3: The method of Example 1, wherein the communication device is a first communication device, and the step of transmitting the second packet in the second frequency segment includes the step of transmitting the second packet to the second communication device in the second frequency segment; and the step of determining that simultaneous transmission and reception through a plurality of frequency segments is not allowed includes the step of determining that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments.

[0147] Example 4: The method of Example 3, wherein the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments, comprising the step of receiving a third packet from the second communication device at the first communication device, wherein the third packet comprises information indicating that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments.

[0148] Example 5: The method of Example 1, wherein the step of determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed comprises the step of determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed in the wireless local area network (WLAN) to which the communication device belongs.

[0149] Example 6: The method of Example 5, wherein the step of determining that simultaneous transmission and reception through a plurality of frequency segments is not allowed in the WLAN comprises, at the communication device, receiving a third packet from an access point managing the WLAN, and the third packet comprises information indicating that simultaneous transmission and reception through a plurality of frequency segments is not allowed in the WLAN.

[0150] Example 7: A method of any one of Examples 1 to 6, further comprising the step of prompting a physical layer (PHY) processor of a communication device to include padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet, in response to a determination that simultaneous transmission and reception through a plurality of frequency segments is not allowed.

[0151] Example 8: A first communication device comprising a wireless network interface device configured to communicate through a plurality of frequency segments. The wireless network interface device determines that simultaneous transmission and reception through the plurality of frequency segments is not allowed; controls the wireless network interface device to transmit a first packet in a first frequency segment starting at a first time; controls the wireless network interface device to transmit a second packet in a second frequency segment starting at a second time different from the first time, wherein the transmission of the second packet overlaps temporally with the transmission of the first packet; and includes one or more integrated circuit (IC) devices configured to include padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet in response to the determination that simultaneous transmission and reception through the plurality of frequency segments is not allowed.

[0152] Example 9: The first communication device in Example 8, wherein the one or more IC devices are configured to determine that the first communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments.

[0153] Example 10: In Example 8, the one or more IC devices: control the wireless network interface device to transmit the second packet to the second communication device in the second frequency segment; and the first communication device configured to determine that simultaneous transmission and reception through the multiple frequency segments is not allowed by determining that at least the second communication device is not allowed to transmit and receive through the multiple frequency segments simultaneously.

[0154] Example 11: The first communication device in Example 10, wherein the one or more IC devices are configured to determine, using information in a third packet received from the second communication device, that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments, and the information in the third packet indicates that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments.

[0155] Example 12: The first communication device in Example 8, wherein the one or more IC devices are configured to determine that simultaneous transmission and reception through multiple frequency segments are not allowed by determining that simultaneous transmission and reception through multiple frequency segments are not allowed in at least the WLAN to which the communication device belongs.

[0156] Example 13: In Example 12, the one or more IC devices are configured to determine that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN by using information in a third packet received from an access point managing the WLAN, and the information in the third packet indicates that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN, a first communication device.

[0157] Example 14: In any one of Examples 8 to 13, the wireless network interface comprises a physical layer (PHY) processor implemented on one or more IC devices; and the one or more IC devices are configured to prompt the PHY processor to include the padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet in response to a decision that simultaneous transmission and reception through a plurality of frequency segments is not permitted.

[0158] Example 15: A method for transmitting simultaneously in a plurality of frequency segments, comprising: a step of performing a backoff operation corresponding to one of the plurality of frequency segments in a communication device, wherein the backoff operation comprises decrementing a backoff counter in relation to the one frequency segment; a step of determining whether the backoff counter of the communication device has expired in the communication device; and a step of transmitting each transmission in each of the frequency segments that start simultaneously by the communication device in response to the determination that the backoff counter has expired.

[0159] Example 16: The method of Example 15, further comprising the step of decrementing the backoff counter when the communication device determines that a sub-channel within the one frequency segment is idle; and the step of stopping the decrementing of the backoff counter when the communication device determines that a sub-channel within the one frequency segment is busy.

[0160] Example 17: The method of Example 16, wherein, in relation to determining that a backoff counter has expired, a communication device further comprises the step of determining whether one or more other sub-channels in a plurality of frequency segments are idle for a predetermined time period prior to the start of each transmission in each frequency segment; and simultaneously transmitting each transmission in each frequency segment that starts simultaneously in response to the determination that one or more other sub-channels in the plurality of frequency segments are idle for a predetermined time period.

[0161] Example 18: The method of Example 17, further comprising the step of deciding to delay the simultaneous transmission of each transmission in each frequency segment in response to determining that one or more other sub-channels in a plurality of frequency segments are in use for a predetermined time period.

[0162] Example 19: In any one of Examples 15 to 18, regarding subsequent simultaneous transmission in a plurality of frequency segments, a method comprising: in a communication device selecting another frequency segment different from the one frequency segment; in a communication device performing another backoff operation corresponding to the other frequency segment different from the one frequency segment, wherein the other backoff operation comprises decrementing the backoff counter or the other backoff counter in relation to the other frequency segment; in a communication device determining whether the backoff counter or the other backoff counter has expired; and in response to determining that the backoff counter or the other backoff counter has expired, the communication device performing subsequent simultaneous transmission in the plurality of frequency segments.

[0163] Example 20: Any one of Examples 15-18 combined with any one of Examples 1-7.

[0164] Example 21: A communication device comprising a wireless network interface device configured to communicate over a plurality of frequency segments, wherein the wireless network interface device comprises one or more IC devices and a backoff counter implemented on the one or more IC devices. The one or more IC devices are configured to: perform a backoff operation corresponding to one of the plurality of frequency segments, wherein the backoff operation involves decrementing the backoff counter in relation to one frequency segment; determine whether the backoff counter has expired; and, in response to the determination that the backoff counter has expired, control the wireless network interface device to simultaneously transmit each of the transmissions on each of the frequency segments that start simultaneously.

[0165] Example 22: The communication device of Example 21, wherein the one or more IC devices are further configured to decrement the backoff counter when it is determined that a sub-channel in the one frequency segment is idle; and to stop decrementing the backoff counter when it is determined that a sub-channel in the one frequency segment is in use.

[0166] Example 23: The communication device of Example 22, wherein the one or more IC devices determine whether one or more other sub-channels within the plurality of frequency segments are idle for a predetermined time period prior to the start of each transmission in each frequency segment in relation to the determination that the backoff counter has expired; and further configured to control the wireless network interface device to simultaneously transmit each transmission in each frequency segment in response to the determination that the one or more other sub-channels within the plurality of frequency segments are idle for the predetermined time period.

[0167] Example 24: The communication device of Example 23, wherein the one or more IC devices are further configured to determine to delay the simultaneous transmission of each transmission in each of the frequency segments in response to a determination that one or more other sub-channels in the plurality of frequency segments are in use during the predetermined time period.

[0168] Example 25: In any one of Examples 21-24, the communication device further configured such that, in relation to subsequent simultaneous transmission in a plurality of frequency segments: selecting another frequency segment different from the one frequency segment; performing another backoff operation corresponding to the other frequency segment different from the one frequency segment, wherein the other backoff operation includes decrementing the backoff counter or the other backoff counter in relation to the other frequency segment; determining whether the backoff counter or the other backoff counter has expired; and controlling the wireless network interface device to perform the subsequent simultaneous transmission in the plurality of frequency segments in response to the determination that the backoff counter or the other backoff counter has expired.

[0169] Example 26: As a communication device of any one of Examples 21-25, the one or more IC devices are further configured to perform the action mentioned in any one of Examples 8-14.

[0170] At least some of the various blocks, operations, and techniques described above may be implemented using hardware, a processor executing firmware instructions, a processor executing software instructions, or any combination thereof. When implemented using a processor executing software or firmware instructions, the software or firmware instructions may be stored in any suitable computer-readable memory, such as random access memory (RAM), read-only memory (ROM), flash memory, etc. When the software or firmware instructions are executed by one or more processors, they may include machine-readable instructions that cause one or more processors to perform various actions.

[0171] When implemented in hardware, the hardware may include discrete components, integrated circuits, ASICs (application-specific integrated circuits), PLDs (programmable logic devices), etc.

[0172] Although the present invention has been described with reference to specific examples intended merely as exemplary and not to limit the invention, changes, additions, and / or deletions may be made to the disclosed embodiments without departing from the scope of the invention.

Claims

Claim 1 A method for transmitting simultaneously across a plurality of frequency segments, comprising: a step of determining in a communication device that simultaneous transmission and reception through the plurality of frequency segments is not permitted; a step of transmitting a first packet in a first frequency segment starting at a first time by the communication device; a step of transmitting a second packet in a second frequency segment starting at a second time different from the first time by the communication device, wherein the transmission of the second packet overlaps temporally with the transmission of the first packet; and a step of including padding in the first packet such that the termination of the transmission of the first packet occurs simultaneously with the termination of the transmission of the second packet in response to the determination that simultaneous transmission and reception through the plurality of frequency segments is not permitted. Claim 2 A method according to claim 1, wherein the step of determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed comprises determining that the communication device is not allowed to simultaneously transmit and receive through the plurality of frequency segments. Claim 3 In claim 1, the communication device is a first communication device, and the step of transmitting the second packet in the second frequency segment includes the step of transmitting the second packet to the second communication device in the second frequency segment; and the step of determining that simultaneous transmission and reception through multiple frequency segments is not allowed includes the second communication device determining that simultaneous transmission and reception through multiple frequency segments is not allowed. Claim 4 A method according to claim 3, wherein determining that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments comprises the step of receiving a third packet from the second communication device at the first communication device, wherein the third packet comprises information indicating that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments. Claim 5 A method according to claim 1, wherein the step of determining that simultaneous transmission and reception through multiple frequency segments is not allowed includes determining that simultaneous transmission and reception through multiple frequency segments is not allowed in a wireless local area network (WLAN) to which the communication device belongs. Claim 6 A method according to claim 5, wherein the step of determining that simultaneous transmission and reception through multiple frequency segments in the WLAN is not allowed comprises, in the communication device, receiving a third packet from an access point managing the WLAN, and the third packet includes information indicating that simultaneous transmission and reception through multiple frequency segments is not allowed in the WLAN. Claim 7 A method according to any one of claims 1 to 6, wherein the method further comprises the step of prompting a physical layer (PHY) processor of the communication device to include padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet, in response to a determination that simultaneous transmission and reception through multiple frequency segments is not allowed. Claim 8 A first communication device comprising a wireless network interface device configured to communicate through a plurality of frequency segments, wherein the wireless network interface device determines that simultaneous transmission and reception through the plurality of frequency segments is not allowed, controls the wireless network interface device to transmit a first packet in a first frequency segment starting at a first time, controls the wireless network interface device to transmit a second packet in a second frequency segment starting at a second time different from the first time, wherein the transmission of the second packet overlaps temporally with the transmission of the first packet, and in response to the determination that simultaneous transmission and reception through the plurality of frequency segments is not allowed, one or more integrated circuit (IC) devices configured to include padding in the first packet such that the termination of the transmission of the first packet occurs simultaneously with the termination of the transmission of the second packet. Claim 9 In claim 8, the above one or more IC devices are configured to determine that the device is not allowed to transmit and receive simultaneously through a plurality of frequency segments, a first communication device. Claim 10 In claim 8, the one or more IC devices control the wireless network interface device to transmit the second packet to the second communication device in the second frequency segment; and the first communication device configured to determine that simultaneous transmission and reception through the multiple frequency segments is not allowed by determining that at least the second communication device is not allowed to transmit and receive simultaneously through the multiple frequency segments. Claim 11 In claim 10, the above one or more IC devices are configured to determine that the second communication device is not allowed to transmit and receive simultaneously through multiple frequency segments using information within a third packet received from the second communication device, and the information within the third packet indicates that the second communication device is not allowed to transmit and receive simultaneously through multiple frequency segments, a first communication device. Claim 12 In claim 8, the first communication device is configured such that the one or more IC devices determine that simultaneous transmission and reception through multiple frequency segments are not allowed by at least determining that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN to which the communication device belongs. Claim 13 In claim 12, the one or more IC devices are configured to determine that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN by using information in a third packet received from an access point managing the WLAN, and the information in the third packet indicates that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN, a first communication device. Claim 14 A first communication device, wherein in any one of claims 8 to 13, the wireless network interface comprises a physical layer (PHY) processor implemented on one or more IC devices; and the one or more IC devices are configured to prompt the PHY processor to include padding in the first packet such that the termination of transmission of the first packet occurs simultaneously with the termination of transmission of the second packet in response to a decision that simultaneous transmission and reception through a plurality of frequency segments is not permitted. Claim 15 A method for transmitting simultaneously across a plurality of frequency segments, comprising: a step of determining in a communication device that simultaneous transmission and reception through a plurality of frequency segments is not allowed; a step of transmitting a first packet in a first frequency segment by the communication device; a step of transmitting a second packet in a second frequency segment by the communication device; a step of determining in the communication device that the termination of the first packet does not coincide with the termination of the second packet; and a step of determining in the communication device that at least one of the first packet and the second packet prompts the transmission of each response packet within a defined time period after the transmission of the corresponding packet among the first packet and the second packet. A method comprising the step of (i) determining that simultaneous transmission and reception through a plurality of frequency segments is not allowed, and (ii) determining that at least one of the first packet and the second packet prompts the transmission of each response packet in a defined time period after the transmission of the corresponding packet among the first packet and the second packet, wherein the communication device includes padding in at least one of the first packet and the second packet such that the termination of transmission of the first packet coincides with the termination of transmission of the second packet. Claim 16 A method according to claim 15, wherein the step of transmitting the first packet includes starting the packet transmission at a first time, and the step of transmitting the second packet includes starting the transmission of the second packet at a second time different from the first time. Claim 17 A method according to claim 15, wherein the step of transmitting the first packet includes starting the transmission of the packet at a specific time, and the step of transmitting the second packet includes starting the transmission of the second packet at the specific time. Claim 18 A method according to any one of claims 15 to 17, wherein the step of determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed comprises determining that the communication device is not allowed to simultaneously transmit and receive through the plurality of frequency segments. Claim 19 A method according to any one of claims 15 to 17, wherein the communication device is a first communication device, and the step of transmitting the second packet in the second frequency segment includes transmitting the second packet to the second communication device in the second frequency segment; and the step of determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed includes determining that the second communication device is not allowed to transmit and receive simultaneously through the plurality of frequency segments. Claim 20 A method according to claim 19, wherein determining that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments comprises receiving a third packet from the second communication device at the first communication device, and the third packet comprises information indicating that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments. Claim 21 A method according to any one of claims 15 to 17, wherein the step of determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed comprises determining that simultaneous transmission and reception through the plurality of frequency segments is not allowed in the WLAN to which the communication device belongs. Claim 22 A method according to claim 21, wherein determining that simultaneous transmission and reception through multiple frequency segments in the WLAN is not allowed comprises receiving a third packet from an access point managing the WLAN in the communication device, wherein the third packet includes information indicating that simultaneous transmission and reception through multiple frequency segments is not allowed in the WLAN. Claim 23 A method according to any one of claims 15 to 17, wherein the step of determining that at least one of the first packet and the second packet prompts the transmission of each acknowledgment packet in the defined time period after the transmission of the corresponding packet among the first packet and the second packet comprises determining at least one of (i) prompting the transmission of the first acknowledgment packet to begin in the defined time period after the end of the transmission of the first packet, and (ii) prompting the transmission of the second acknowledgment packet to begin in the defined time period after the end of the transmission of the second packet. Claim 24 A method according to any one of claims 15 to 17, wherein the method further comprises the step of (i) determining that simultaneous transmission and reception through a plurality of frequency segments is not permitted, and (ii) prompting a physical layer (PHY) processor of the communication device to include padding in at least one of the first packet and the second packet in response to determining that at least one of the first packet and the second packet prompts the transmission of each response packet in the defined time period after the transmission of the corresponding packet among the first packet and the second packet, such that the termination of transmission of the first packet coincides with the termination of transmission of the second packet. Claim 25 A first communication device comprises a wireless network interface device configured to communicate through a plurality of frequency segments, wherein the wireless network interface device determines that simultaneous transmission and reception through the plurality of frequency segments is not allowed, controls the wireless network interface device to transmit a first packet in a first frequency segment, controls the wireless network interface device to transmit a second packet in a second frequency segment, determines that the termination of the first packet does not coincide with the termination of the second packet, and determines that at least one packet among the first packet and the second packet prompts the transmission of each response packet within a defined time period after the transmission of the corresponding packet among the first packet and the second packet, and in response to (i) the determination that simultaneous transmission and reception through the plurality of frequency segments is not allowed, and (ii) the determination that at least one packet among the first packet and the second packet prompts the transmission of each response packet within the defined time period after the transmission of the corresponding packet among the first packet and the second packet, padding the first packet such that the termination of transmission of the first packet coincides with the termination of transmission of the second packet. A first communication device having one or more integrated circuit (IC) devices configured to be included in at least one of the second packets. Claim 26 In paragraph 25, the above one or more IC devices are configured to control the wireless network interface device to start transmitting the first packet at a first time, and to control the wireless network interface device to start transmitting the second packet at a second time different from the first time, a first communication device. Claim 27 In paragraph 25, the above one or more IC devices are configured to control the wireless network interface device to start transmitting the first packet at a specific time, and to control the wireless network interface device to start transmitting the second packet at the specific time, a first communication device. Claim 28 In any one of claims 25 to 27, the first communication device is configured such that the one or more IC devices determine that the first communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments. Claim 29 A first communication device configured such that, in any one of claims 25 to 27, the one or more IC devices control the wireless network interface device to transmit the second packet to the second communication device in the second frequency segment, and determine that simultaneous transmission and reception through the multiple frequency segments is not allowed by determining that at least the second communication device is not allowed to transmit and receive simultaneously through the multiple frequency segments. Claim 30 In claim 29, the one or more IC devices are configured to determine, using information in a third packet received from the second communication device, that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments, and the information in the third packet indicates that the second communication device is not allowed to transmit and receive simultaneously through a plurality of frequency segments, a first communication device. Claim 31 A first communication device configured such that, in any one of claims 25 to 27, the one or more IC devices determine that simultaneous transmission and reception through multiple frequency segments are not allowed by determining that simultaneous transmission and reception through multiple frequency segments are not allowed in at least the WLAN to which the first communication device belongs. Claim 32 In claim 31, the one or more IC devices are configured to determine that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN using information in a third packet received from an access point managing the WLAN, and the information in the third packet indicates that simultaneous transmission and reception through multiple frequency segments are not allowed in the WLAN, a first communication device. Claim 33 A first communication device configured such that, in any one of claims 25 to 27, the one or more IC devices determine at least one of (i) the first packet prompts the transmission of a first acknowledgment packet in the defined time period after the end of the transmission of the first packet, and (ii) the second packet prompts the transmission of a second acknowledgment packet in the defined time period after the end of the transmission of the second packet, thereby determining that at least one of the first packet and the second packet prompts the transmission of each acknowledgment packet in the defined time period after the transmission of the corresponding packet among the first packet and the second packet. Claim 34 A first communication device, wherein in any one of claims 25 to 27, the wireless network interface comprises a physical layer (PHY) processor implemented on one or more IC devices, and the one or more IC devices are configured to prompt the physical layer (PHY) processor of the first communication device to include padding in at least one of the first packet and the second packet such that the end of the transmission of the first packet coincides with the end of the transmission of the second packet, in response to (i) determining that simultaneous transmission and reception through a plurality of frequency segments is not permitted, and (ii) determining that at least one of the first packet and the second packet prompts the transmission of each response packet in the defined time period after the transmission of the corresponding packet among the first packet and the second packet.

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