Padding and backoff operations when transmitting over multiple frequency segments in a WLAN

Abstract

SOLUTION: A method of simultaneous transmission in multiple frequency segments in a communication device comprises: determining that simultaneous transmission and reception via multiple frequency segments in a WLAN is not permitted; transmitting a first packet in a first frequency segment beginning at a first time; and transmitting a second packet in a second frequency segment beginning at a second time different from the first time, where the transmission of the second packet overlaps in time with transmission of the first packet; and, in response to having determined that simultaneous transmission and reception via multiple frequency segments is not permitted, including padding in the first packet so that an end of the transmission of the first packet occurs at the same time as an end of the transmission of the second packet.EFFECT: It is possible to determine when simultaneous transmission in multiple frequency segments can begin.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 863,699, entitled "Multi-Band Operation: Synchronized and Unsynchronized," filed June 19, 2019, which is incorporated herein by reference in its entirety.

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

[0003] Wireless local area networks (WLANs) have evolved rapidly over the past two decades, with the development of WLAN standards such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards enabling increased single-user peak data rates. One approach to increasing data rates is by increasing the frequency bandwidth of the communication channels used in WLANs. For example, the IEEE 802.11n standard allows the aggregation of two 20 MHz subchannels to form a 40 MHz aggregate communication channel. In contrast, the more recent IEEE 802.11ax standard allows the aggregation of up to eight 20 MHz subchannels to form an aggregate communication channel of up to 160 MHz. Work is currently underway on a new version of the IEEE 802.11 standard, referred to as the IEEE 802.11be standard or Very High Throughput (EHT) WLAN. The IEEE 802.11be standard may allow the aggregation of as many as 16 20 MHz subchannels (or possibly even more) to form an aggregate communication channel of up to 320 MHz (or possibly even wider). Additionally, the IEEE 802.11be standard may allow aggregation of 20 MHz subchannels in different frequency segments (e.g., separated by a frequency gap) to form respective communication links. Furthermore, the IEEE 802.11be standard may allow aggregation of 20 MHz subchannels in different radio frequency (RF) bands to form a single aggregated channel, and may allow aggregation of 20 MHz subchannels in different RF bands to form respective communication links.

[0004] The current IEEE 802.11 standard (for brevity, referred to herein as the "IEEE 802.11 standard") 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 a mechanism for a device to determine whether the single communication channel is busy or idle for purposes of determining whether the device can transmit within the single communication channel. Summary of the Invention

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

[0006] In another embodiment, a first communications device comprises a wireless network interface device configured to communicate over multiple frequency segments, the wireless network interface device having one or more integrated circuit (IC) devices configured to: determine that simultaneous transmission and reception over multiple frequency segments is not permitted; control the wireless network interface device to transmit a first packet in a first frequency segment beginning at a first time; control the wireless network interface device to transmit a second packet in a second frequency segment beginning at a second time different from the first time, where transmission of the second packet overlaps in time with transmission of the first packet; and, in response to determining that simultaneous transmission and reception over multiple frequency segments is not permitted, include padding in the first packet such that an end of transmission of the first packet occurs simultaneously with an end of transmission of the second packet.

[0007] In yet another embodiment, a method for simultaneously transmitting in multiple frequency segments comprises: performing, at a communication device, a backoff operation corresponding to a frequency segment among the multiple frequency segments, the backoff operation involving decrementing a backoff counter associated with the one frequency segment; determining, at the communication device, whether the backoff counter of the communication device has expired; and, in response to determining that the backoff counter has expired, the communication device simultaneously transmitting respective transmissions in the respective frequency segments starting at the same time.

[0008] In yet another embodiment, a communications device comprises a wireless network interface device configured to communicate over multiple frequency segments, the wireless network interface device having one or more IC devices and a back-off counter implemented on the one or more IC devices, the one or more IC devices configured to: perform a back-off operation corresponding to a frequency segment among the multiple frequency segments, the back-off operation involving decrementing the back-off counter associated with the frequency segment; determine whether the back-off counter has expired; and, in response to determining that the back-off counter has expired, control the wireless network interface device to simultaneously transmit respective transmissions in the respective frequency segments starting simultaneously. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram of an exemplary communication system in which communication devices wirelessly exchange information over multiple frequency segments, according to one embodiment.

[0010] [Figure 2A]2 is a diagram of an exemplary communication channel used by the communication system of FIG. 1 corresponding to multiple frequency segments, according to one embodiment.

[0011] [Figure 2B] 10 is a diagram of another exemplary communication channel used by the communication system of FIG. 1 corresponding to multiple frequency segments, according to another embodiment.

[0012] [Figure 3] FIG. 1 is a block diagram of an exemplary wireless network interface device configured to communicate over multiple frequency segments, according to one embodiment.

[0013] [Figure 4] FIG. 1 is a diagram of an example of asynchronous transmission in multiple frequency segments, according to one embodiment.

[0014] [Figure 5] 1 is a flow diagram of an exemplary method for transmitting simultaneously in multiple frequency segments, according to one embodiment.

[0015] [Figure 6] FIG. 10 is a flow diagram of another exemplary method for simultaneously transmitting in multiple frequency segments, according to one embodiment.

[0016] [Figure 7] FIG. 1 is a diagram of an example of synchronous simultaneous transmission in multiple frequency segments, according to one embodiment.

[0017] [Figure 8] FIG. 10 is a diagram of another example of synchronous simultaneous transmission in multiple frequency segments according to another embodiment.

[0018] [Figure 9] FIG. 10 is a flow diagram of another exemplary method for simultaneously transmitting in multiple frequency segments, according to one embodiment.

[0019] [Figure 10] FIG. 10 is a diagram of another example of synchronous simultaneous transmission in multiple frequency segments according to another embodiment.

[0020] [Figure 11] FIG. 10 is a diagram of an example of synchronous simultaneous transmission in multiple frequency segments according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Next-generation wireless local area network (WLAN) protocols (e.g., the IEEE 802.11be standard, sometimes referred to as the Very High Throughput (EHT) WLAN standard) may allow aggregation of as many as 16 (or perhaps even more) 20 MHz subchannels to form a 320 MHz aggregate communication channel (or perhaps an even wider aggregate communication channel). Additionally, the IEEE 802.11be standard may allow aggregation of 20 MHz subchannels in different frequency segments (e.g., separated by a frequency gap) to form respective communication links. Additionally, the IEEE 802.11be standard may allow formation of multiple WLAN communication links corresponding to respective frequency segments. The multiple WLAN communication links may be used to simultaneously transmit / receive different information.

[0022] In some embodiments described below, multiple packets are transmitted simultaneously within respective frequency segments beginning at different times, and padding is included in one or more of the packets so that transmission of the multiple packets ends simultaneously.

[0023] In some embodiments described below, a respective backoff operation is performed in association with each frequency segment to determine when simultaneous transmissions in multiple frequency segments may begin. In other embodiments described below, a single backoff operation is performed in association with only one frequency segment to determine when simultaneous transmissions in multiple frequency segments may begin.

[0024] 1 is a diagram of an exemplary WLAN 110 that employs 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 with a host processor 118 coupled to a wireless network interface device 122. The wireless network interface device 122 includes one or more medium access control (MAC) processors 126 (which may be referred to herein as “MAC processors 126” for brevity) and one or more PHY processors 130 (which may be referred to herein as “PHY processors 130” for brevity). The PHY processor 130 includes multiple transceivers 134, which are coupled to multiple antennas 138. While three transceivers 134 and three antennas 138 are shown in FIG. 1, in other embodiments, the AP 114 includes other suitable numbers of transceivers 134 and antennas 138 (e.g., one, two, four, five, etc.). In some embodiments, the AP 114 includes more antennas 138 than the transceivers 134, and antenna switching techniques are utilized.

[0025] In one embodiment, the wireless network interface device 122 is configured for operation 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 within respective frequency segments within the 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 within respective RF bands 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, each corresponding to a respective RF band. In another embodiment, the wireless network interface device 122 includes a single PHY processor 130, in which each transceiver 134 includes a respective RF radio corresponding to a respective RF band.

[0026] 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 a first IC, and the PHY processor 130 may be implemented at least partially on a second IC. For example, in various embodiments, the first IC and the second IC may be packaged together in a single IC package to form a modular device or may be coupled together on a single printed circuit board. 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). The SoC includes at least a portion of the MAC processor 126 and at least a portion of the PHY processor 130.

[0027] In one embodiment, host processor 118 includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as, for example, random access memory (RAM), read-only memory (ROM), flash memory, etc. In one embodiment, host processor 118 may be implemented at least partially on a first IC, and network device 122 may be implemented at least partially on a second IC. As another example, host processor 118 and at least a portion of wireless network interface device 122 may be implemented on a single IC.

[0028] In various embodiments, the MAC processor 126 and / or the PHY processor 130 of the AP 114 are configured to generate and process received data units compliant with a WLAN communication protocol, such as a communication protocol compliant with the IEEE 802.11 standard or another suitable wireless communication protocol. 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 MAC service data units (MSDUs), MAC protocol data units (MPDUs), etc., and provide the MAC layer data units to the PHY processor 130. Additionally, in some embodiments, the MAC processor 126 is configured to select a communication link over which the MAC layer data units should be transmitted and to control the PHY processor 130 to transmit the MAC layer data units within the selected communication link. Also, in some embodiments, MAC processor 126 is configured to determine when each communication link is idle and available for transmission and to control PHY processor 130 so that MAC layer data units are transmitted when the respective communication link is idle. Additionally, in some embodiments, MAC processor 126 is configured to determine when a client station is asleep and therefore unavailable for transmission or reception. For example, according to some embodiments, MAC processor 126 is configured to negotiate a schedule with a client station regarding when the client station is allowed to sleep and when the client station should wake up and be available for transmission or reception to or from the AP 114.

[0029] PHY processor 130 may be configured to receive MAC layer data units from MAC processor 126 and encapsulate the MAC layer data units to generate PHY data units, such as PHY protocol data units (PPDUs), for transmission via antenna 138. Similarly, PHY processor 130 may be configured to receive PHY data units received via antenna 138 and extract the MAC layer data units encapsulated within the PHY data units. PHY processor 130 may provide the extracted MAC layer data units to MAC processor 126, which processes the MAC layer data units.

[0030] A PHY data unit may be referred to herein as a "packet," and a MAC layer data unit may be referred to herein as a "frame."

[0031] According to one embodiment, in connection with generating one or more RF signals for transmission, PHY processor 130 is configured to process (which may include modulating, filtering, etc.) data corresponding to the PPDU to generate one or more digital baseband signals and convert the digital baseband signals to one or more analog baseband signals. Additionally, PHY processor 130 is configured to upconvert the one or more analog baseband signals to one or more RF signals for transmission via one or more antennas 138.

[0032] In connection with receiving the one or more RF signals, PHY processor 130 is configured to downconvert the one or more RF signals to one or more analog baseband signals and convert the one or more analog baseband signals to one or more digital baseband signals. PHY processor 130 is further configured to process (which may include demodulating, filtering, etc.) the one or more digital baseband signals to generate a PPDU.

[0033] In various embodiments, the PHY processor 130 includes an amplifier (e.g., a low noise amplifier (LNA), a power amplifier, etc.), an RF downconverter, an RF upconverter, multiple 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.

[0034] PHY processor 130 is configured to generate one or more RF signals that are provided to one or more antennas 138. PHY processor 130 is also configured to receive one or more RF signals from one or more antennas 138.

[0035] According to some embodiments, MAC processor 126 is configured to control PHY processor 130 to generate one or more RF signals, for example, by providing one or more MAC layer data units (e.g., MPDUs) to PHY processor 130 and optionally by providing one or more control signals to PHY processor 130. In one embodiment, MAC processor 126 includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as, for example, RAM, ROM, flash memory, etc. In other embodiments, MAC processor 126 additionally or alternatively includes one or more hardware state machines.

[0036] According to some embodiments, MAC processor 126 includes or implements a backoff controller 140 configured to implement a backoff procedure in connection with determining when a transmission in a communication channel can proceed. Backoff controller 140 includes one or more backoff counters (sometimes referred to as timers) 142. When network interface device 122 transmits, backoff controller 140 invokes a backoff procedure when network interface device 122 determines that transmission of a data unit failed and should be retransmitted. The backoff procedure generally involves setting backoff counter 142 and decrementing backoff counter 142 to determine when network interface device 122 can transmit a frame.

[0037] According to some embodiments, backoff counter 142 is set to a randomly or pseudo-randomly chosen value so that the backoff counters of different communication devices in the network tend to reach zero at different times. Backoff controller 140 controls backoff counter 142 to decrement while determining that the channel medium is idle. On the other hand, if backoff controller 140 determines that the communication medium is busy, it suspends backoff counter 142 and does not resume decrementing backoff counter 142 until the communication medium is later determined to be idle. Generally, when backoff counter 142 reaches zero, backoff controller 140 determines that the communication device is free to transmit. In some embodiments, prior to transmission, network interface device 122 also determines whether the subchannel on which the transmission is to occur has been idle for a predetermined period of time immediately prior to the start of transmission. In some embodiments, if backoff counter 142 reaches zero but the subchannel on which the transmission is to occur has not been idle for a predetermined period of time immediately prior to the start of transmission, the transmission does not occur and the backoff counter is reset.

[0038] In one embodiment, determining whether the channel medium is idle includes measuring an energy level in the channel medium and comparing the measured energy level to a threshold. According to one embodiment, if the measured energy level is less than the threshold, the channel medium is determined to be idle; conversely, 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, PHY processor 130 includes one or more energy sensors (not shown) that measure energy levels in one or more frequency segments of the communication channel, and the measured energy levels are used to determine whether the channel medium is idle.

[0039] In one embodiment, setting the backoff counter 142 includes randomly or pseudo-randomly selecting an initial value for the backoff counter 142 from a range of initial values. In one embodiment, the initial value ranges from [0, CW], where CW is a contention window parameter, the initial value and CW are in units of slots, and each slot corresponds to an appropriate period. For example, the IEEE 802.11 standard defines slot times of 20 microseconds (IEEE 802.11b) and 9 microseconds (IEEE 802.11a, 11n, and 11ac), and 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 attempted transmission fails (e.g., failure to receive an acknowledgment of the transmission), the value of CW is approximately doubled, up to a maximum of CWmax. The parameters CWmin and CWmax are also in units of slots. In one embodiment, the backoff counter 142 is decremented in units of slots.

[0040] In some embodiments, at least in some scenarios, when a communication channel includes multiple frequency segments, multiple respective backoff counters 142 are maintained for the multiple frequency segments. In some embodiments, at least in some scenarios, when a communication channel includes multiple frequency segments, a single backoff counter 142 is maintained for one of the multiple frequency segments.

[0041] In various embodiments, the back-off controller 140 performs one or more (or none of) of the various operations related to one or more back-off counters 142, which are described in more detail below, such as: i) determining whether to use multiple back-off counters 142 corresponding to respective frequency segments when transmitting simultaneously over multiple frequency segments; ii) selecting one frequency segment to which the single back-off counter 142 corresponds when a single back-off counter 142 is utilized when transmitting simultaneously over multiple frequency segments;

[0042] In one embodiment, backoff controller 140 is implemented by a processor executing machine-readable instructions stored in a memory, the machine-readable instructions causing the processor to perform the operations described in more detail below. In another embodiment, backoff controller 140 additionally or alternatively comprises hardware circuitry (e.g., one or more counters, one or more timers, one or more hardware state machines, etc.) configured to perform the operations described in more detail below. In some embodiments in which the hardware circuitry comprises one or more hardware state machines, the one or more hardware state machines are configured to perform the operations described in more detail below.

[0043] Additionally or alternatively, according to one embodiment, MAC processor 126 includes or implements a synchronous transmission controller 146 configured to determine when multiple transmissions in multiple respective frequency segments are synchronized (e.g., multiple transmissions begin and, optionally, end simultaneously). In some embodiments in which multiple back-off counters 142 corresponding to respective frequency segments are used when simultaneously transmitting over multiple frequency segments, synchronous transmission controller 146 postpones transmission in all of the multiple frequency segments until all of the multiple back-off counters 142 have expired (e.g., reached zero). In some embodiments, when simultaneous transmissions over multiple frequency segments are asynchronous (e.g., each transmission in each frequency segment begins at a different time), synchronous transmission controller 146 is configured to control PHY processor 130 so that each transmission in each frequency segment ends simultaneously.

[0044] In one embodiment, synchronous transmission controller 146 is implemented by a processor that executes machine-readable instructions stored in memory, the machine-readable instructions causing the processor to perform the operations described in more detail below. In another embodiment, synchronous transmission controller 146 additionally or alternatively comprises hardware circuitry configured to perform the operations described in more detail below. In some embodiments, the hardware circuitry comprises one or more hardware state machines configured to perform the operations described in more detail below.

[0045] In other embodiments, the backoff controller 140 and / or the synchronous transmission controller 146 are omitted from the AP 114 .

[0046] The WLAN 110 also includes multiple client stations 154. While three client stations 154 are shown in FIG. 1 , in various embodiments, the WLAN 110 includes any other suitable number of client stations 154 (e.g., one, two, four, five, six, etc.). The 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 (for simplicity, may be referred to herein as “MAC processors 166”) and one or more PHY processors 170 (for simplicity, may be referred to herein as “PHY processors 170”). The PHY processor 170 includes multiple transceivers 174, which are coupled to multiple antennas 178. 1 shows three transceivers 174 and three antennas 178, in other embodiments, the client station 154-1 includes other suitable numbers (e.g., one, two, four, five, etc.) of transceivers 174 and antennas 178. In some embodiments, the client station 154-1 includes more antennas 178 than transceivers 174, and antenna switching techniques are utilized.

[0047] In one embodiment, the wireless network interface device 162 is configured for operation within a single RF band at a given time. In another embodiment, the wireless network interface device 162 is configured for operation within two or more RF bands, either simultaneously or at different times. For example, in one embodiment, the wireless network interface device 162 includes multiple PHY processors 170, each PHY processor 170 corresponding to a respective RF band. In another embodiment, the wireless network interface device 162 includes a single PHY processor 170, each transceiver 174 including a respective RF radio corresponding to a respective RF band. In one embodiment, the wireless network interface device 162 includes multiple MAC processors 166, each MAC processor 166 corresponding to a respective RF band. In another embodiment, the wireless network interface device 162 includes a single MAC processor 166 corresponding to multiple RF bands.

[0048] The wireless network interface device 162 may be implemented using one or more ICs configured to operate as described below. For example, the MAC processor 166 may be implemented on at least a first IC, and the PHY processor 170 may be implemented on at least a second IC. For example, in various embodiments, the first IC and the second IC may be packaged together in a single IC package to form a modular device or may be coupled together on a single printed circuit board. 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. The SoC includes at least a portion of the MAC processor 166 and at least a portion of the PHY processor 170.

[0049] In one embodiment, host processor 158 includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as, for example, RAM, ROM, flash memory, etc. In one embodiment, host processor 158 may be implemented at least partially on a first IC, and network device 162 may be implemented at least partially on a second IC. As another example, host processor 158 and at least a portion of wireless network interface device 162 may be implemented on a single IC.

[0050] In various embodiments, MAC processor 166 and PHY processor 170 of client station 154-1 are configured to generate and process received data units conforming to a WLAN communication protocol or another suitable communication protocol. For example, MAC processor 166 may be configured to implement MAC layer functions, including those of the WLAN communication protocol, and PHY processor 170 may be configured to implement PHY functions, including those of the WLAN communication protocol. MAC processor 166 may be configured to generate MAC layer data units, such as MSDUs, MPDUs, etc., and provide the MAC layer data units to PHY processor 170. Additionally, in some embodiments, MAC processor 166 is configured to select a communication link over which the MAC layer data unit is to be transmitted and to control PHY processor 170 to transmit the MAC layer data unit within the selected communication link. Also, in some embodiments, MAC processor 166 is configured to determine when each communication link is idle and available for transmission and to control PHY processor 170 to transmit the MAC layer data unit when the respective communication link is idle. Additionally, in some embodiments, the MAC processor 166 is configured to control when portions of the wireless network interface device 162 are asleep or awake, e.g., to conserve power. 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 sleep and when the client station 154-1 should be awake and available to transmit to or receive from the AP 114.

[0051] PHY processor 170 may be configured to receive MAC layer data units from MAC processor 166 and encapsulate the MAC layer data units to generate PHY data units, such as PPDUs, for transmission via antenna 178. Similarly, PHY processor 170 may be configured to receive PHY data units received via antenna 178 and extract the MAC layer data units encapsulated within the PHY data units. PHY processor 170 may provide the extracted MAC layer data units to MAC processor 166, which processes the MAC layer data units.

[0052] According to one embodiment, PHY processor 170 is configured to downconvert one or more RF signals received via one or more antennas 178 to one or more baseband analog signals and convert the analog baseband signals to one or more digital baseband signals. PHY processor 170 is further configured to process the one or more digital baseband signals, demodulate the one or more digital baseband signals, and generate PPDUs. PHY processor 170 includes an amplifier (e.g., an LNA, a power amplifier, etc.), an RF downconverter, an RF upconverter, multiple filters, one or more ADCs, one or more DACs, one or more DFT calculators (e.g., FFT calculators), one or more IDFT calculators (e.g., IFFT calculators), one or more modulators, one or more demodulators, etc.

[0053] PHY processor 170 is configured to generate one or more RF signals that are provided to one or more antennas 178. PHY processor 170 is also configured to receive one or more RF signals from one or more antennas 178.

[0054] According to some embodiments, MAC processor 166 is configured to control PHY processor 170 to generate one or more RF signals, for example, by providing one or more MAC layer data units (e.g., MPDUs) to PHY processor 170 and optionally by providing one or more control signals to PHY processor 170. In one embodiment, MAC processor 166 includes a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as, for example, RAM, ROM, flash memory, etc. In one embodiment, MAC processor 166 includes a hardware state machine.

[0055] According to some embodiments, MAC processor 166 includes or implements a backoff controller 190 that is the same as or similar to backoff controller 140. Backoff controller 190 includes one or more backoff counters (sometimes referred to as timers) 192. Backoff controller 190 controls decrementing of backoff counter 192 while determining that the channel medium is idle. On the other hand, if backoff controller 190 determines that the communication medium is busy, it suspends backoff counter 192 and does not resume decrementing backoff counter 192 until the communication medium is later determined to be idle. Generally, if the communication medium is still idle, when backoff counter 192 reaches zero, backoff controller 190 determines that the communication device is free to transmit. On the other hand, if the communication medium is busy, when backoff counter 192 reaches zero, backoff controller 190 resets backoff counter 192 and the process repeats.

[0056] In some embodiments, at least in some scenarios, when a communication channel includes multiple frequency segments, multiple respective backoff counters 192 are maintained for the multiple frequency segments. In some embodiments, at least in some scenarios, when a communication channel includes multiple frequency segments, a single backoff counter 192 is maintained for one of the multiple frequency segments.

[0057] In various embodiments, the backoff controller 190 performs one or more (or none of) of the 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 multiple backoff counters 192 corresponding to respective frequency segments when transmitting simultaneously over multiple frequency segments; ii) selecting one frequency segment to which the single backoff counter 192 corresponds when a single backoff counter 192 is utilized when transmitting simultaneously over multiple frequency segments;

[0058] In one embodiment, backoff controller 190 is implemented by a processor executing machine-readable instructions stored in a memory, the machine-readable instructions causing the processor to perform the operations described in more detail below. In another embodiment, backoff controller 190 additionally or alternatively comprises hardware circuitry (e.g., one or more counters, one or more timers, one or more hardware state machines, etc.) configured to perform the operations described in more detail below. In some embodiments in which the hardware circuitry comprises one or more hardware state machines, the one or more hardware state machines are configured to perform the operations described in more detail below.

[0059] Additionally or alternatively, according to some embodiments, MAC processor 166 includes or implements a synchronous transmission controller 196 that is the same as or similar to synchronous transmission controller 146. According to one embodiment, synchronous transmission controller 196 is configured to determine when multiple transmissions in multiple respective frequency segments are synchronized (e.g., the multiple transmissions begin and, optionally, end simultaneously). In some embodiments in which multiple back-off counters 192 corresponding to the respective frequency segments are used when simultaneously transmitting over multiple frequency segments, synchronous transmission controller 196 postpones transmission in all of the multiple frequency segments until all of the multiple back-off counters 192 have expired (e.g., reached zero). In some embodiments, when the simultaneous transmissions over multiple frequency segments are asynchronous (e.g., the respective transmissions in the respective frequency segments begin at different times), synchronous transmission controller 196 is configured to control PHY processor 170 so that the respective transmissions in the respective frequency segments end simultaneously.

[0060] In one embodiment, synchronous transmission controller 196 is implemented by a processor that executes machine-readable instructions stored in memory, the machine-readable instructions causing the processor to perform the operations described in more detail below. In another embodiment, synchronous transmission controller 196 additionally or alternatively comprises hardware circuitry configured to perform the operations described in more detail below. In some embodiments, the hardware circuitry comprises one or more hardware state machines configured to perform the operations described in more detail below.

[0061] In one embodiment, each of 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 client stations 154-2 and 154-3 has a suitable structure different from client station 154-1. Each of client stations 154-2 and 154-3 has the same or a different number of transceivers and antennas. For example, according to one embodiment, client station 154-2 and / or client station 154-3 each have only two transceivers and two antennas (not shown).

[0062] 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 multiple sub-channels 204 in a first frequency segment 208 and multiple sub-channels 212 in a second frequency segment 216. The operating channel 200 spans an entire bandwidth 220. In one embodiment, the first frequency segment 208 and the second frequency segment 216 are within the same radio frequency (RF) band.

[0063] In another embodiment, the first frequency segment 208 and the second frequency segment 216 are in different RF bands. The Federal Communications Commission (FCC) currently permits wireless local area networks (WLANs) to operate in multiple RF bands, such as the 2.4 GHz band (approximately 2.4 GHz to 2.5 GHz) and the 5 GHz band (approximately 5.170 GHz to 5.835 GHz). Recently, the FCC proposed allowing WLANs to operate in the 6 GHz band (5.925 GHz to 7.125 GHz). Regulatory authorities in other countries / regions also permit WLAN operation in the 2.4 GHz and 5 GHz bands and are considering permitting WLAN operation in the 6 GHz band. Future WLAN protocols currently being developed may permit multi-band operation, allowing WLANs to simultaneously use spectrum in multiple RF bands.

[0064] 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 transmission.

[0065] 2A , the first frequency segment 208 spans 160 MHz, and the second frequency segment 216 spans 80 MHz. In other embodiments, the first frequency segment 208 includes another suitable number (e.g., 1, 2, 4, etc.) of subchannels 204 and spans another suitable bandwidth, such as, for example, 20 MHz, 40 MHz, 80 MHz, etc., and / or the second frequency segment 216 includes another suitable number (e.g., 1, 2, 8, etc.) of subchannels 212 and spans another suitable bandwidth, such as, for example, 20 MHz, 40 MHz, 160 MHz, etc.

[0066] One subchannel 204-1 in the first frequency segment 208 is designated as a primary subchannel, and the other subchannels 204 / 212 are designated as secondary subchannels. According to some embodiments, control and / or management frames are transmitted within the primary subchannel 204-1. In some embodiments, the primary subchannel must be idle for any of the subchannels 204 / 212 to be used for transmission. In some embodiments, the subchannel 212 in the second frequency segment 216 is also designated as a primary subchannel (not shown). In some embodiments in which the second frequency segment 216 also includes a primary subchannel, at least in some scenarios, control and / or management frames are additionally or alternatively transmitted within the primary subchannel of the second frequency segment 216. In other embodiments, control and / or management frames are transmitted only within the primary subchannel 204-1 of the first frequency segment 208.

[0067] According to some embodiments, in some embodiments where the second frequency segment 216 also includes a primary subchannel, the primary subchannel 204-1 of the first frequency segment 208 must be idle for any of the subchannels 204 to be used for transmission, and the primary subchannel of the second frequency segment 216 must be idle for any of the subchannels 212 to be used for transmission. According to some embodiments, in other embodiments, one or more of the secondary subchannels 204 may be used for transmission even if the primary subchannel 204-1 is not idle, and / or one or more of the secondary subchannels 212 may be used for transmission even if the primary subchannel of the second frequency segment 216 is not idle.

[0068] In other embodiments, the subchannels 212 in the second frequency segment 216 are not designated as primary subchannels.

[0069] In one embodiment, backoff counter 142 / 192 (FIG. 1) corresponds to a primary subchannel of operating channel 200; e.g., when the primary subchannel is idle, backoff counter 142 / 192 is decremented, and when the primary subchannel is busy, backoff counter 142 / 192 is paused. In one embodiment, each backoff counter 142 / 192 (FIG. 1) corresponds to a respective primary subchannel of operating channel 200; e.g., when the respective primary subchannel is idle, each backoff counter 142 / 192 is decremented, and when the respective primary subchannel is busy, each backoff counter 142 / 192 is paused.

[0070] 2B is a diagram of another exemplary operating channel 250 used in the communication system 110 of FIG. 1 in accordance with another embodiment. The operating channel 250 is similar to the exemplary operating channel 200 of FIG. 2A, and like-numbered elements will not be 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 frequency gap 254. 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.

[0071] In one embodiment, backoff counter 142 / 192 (FIG. 1) corresponds to a primary subchannel of operating channel 250; e.g., when the primary subchannel is idle, backoff counter 142 / 192 is decremented, and when the primary subchannel is busy, backoff counter 142 / 192 is paused. In one embodiment, each backoff counter 142 / 192 (FIG. 1) corresponds to a respective primary subchannel of operating channel 250; e.g., when the respective primary subchannel is idle, each backoff counter 142 / 192 is decremented, and when the respective primary subchannel is busy, each backoff counter 142 / 192 is paused.

[0072] 2A and 2B, according to some embodiments, one or more of the sub-channels 204 / 212 are “punctured” (not shown in FIGS. 2A and 2B), e.g., nothing is transmitted within the “punctured” sub-channels.

[0073] 2A and 2B are shown as including two frequency segments 208 / 216, other suitable operating channels include three or more frequency segments (e.g., including a third frequency segment, including 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 gap in frequency within which nothing is transmitted, similar to gap 254. In some embodiments, the third frequency segment is contiguous in frequency with the second frequency segment 216.

[0074] In some embodiments, each frequency segment, such as those shown in Figures 2A and 2B, is associated with a different MAC address. For example, in embodiments in which each frequency segment is used as a respective communication link, each communication link corresponds to a different MAC address.

[0075] 3 is a diagram of an exemplary network interface device 300 configured for simultaneous communication over multiple communication links in respective frequency segments, according to one embodiment. Network interface device 300 is one embodiment of network interface device 122 of AP 114 of FIG. 1. Network interface device 300 is one embodiment of network interface device 162 of client station 154-1 of FIG. 1. In other embodiments, network interface device 122 and / or network interface device 162 have a suitable structure different from network interface device 300. Additionally, in some embodiments, network interface device 300 is used in a suitable communication device other than the communication device of FIG. 1 and / or in a suitable wireless network other than the wireless network of FIG. 1.

[0076] In the illustrated embodiment, the network interface device 300 is configured for simultaneous communication over a first communication link in a first frequency segment and a second communication link in a second frequency segment.

[0077] The network interface device 300 includes a MAC processor 304 coupled to a PHY processor 308. The MAC processor 304 exchanges frames (or PSDUs) with the PHY processor 308.

[0078] In one embodiment, MAC processor 304 corresponds to MAC processor 126 of Figure 1. In another embodiment, MAC processor 304 corresponds to MAC processor 166 of Figure 1. In one embodiment, PHY processor 308 corresponds to one or more PHY processors 130 of Figure 1. In another embodiment, PHY processor 308 corresponds to one or more PHY processors 170 of Figure 1.

[0079] 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 respond to receiving data to be transferred to another communication device within the WLAN (e.g., from a host processor (not shown), from a wired communication link (not shown), etc.), encapsulate the data into MAC layer data units, such as MSDUs, MPDUs, aggregated MPDUs (A-MPDUs), etc., for transmission over the multiple communication links, and decapsulate data from MSDUs, MPDUs, A-MPDUs, etc. received over the multiple communication links. Additionally, in some embodiments, the common MAC logic 312 is configured to select a communication link over which the MAC layer data unit is to be transmitted.

[0080] Each LS MAC logic 316 generally implements MAC layer functions specific to the particular communication link that the LS MAC logic 316 corresponds to. For example, in some embodiments, the LS MAC logic 316a is configured to determine when a first communication link is idle and available for transmission, and the LS MAC logic 316b is configured to determine when a 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), i.e., the LS MAC logic 316a is associated with a first network address (e.g., a first MAC address) and the LS MAC logic 316a is associated with a second network address (e.g., a second MAC address) that is different from the first network address.

[0081] In some embodiments, the common MAC logic 312 implements the backoff controllers 140 / 190 described above with reference to Figure 1. In some embodiments, the common MAC logic 312 additionally or alternatively implements the synchronous transmission controller 196 described above with reference to Figure 1. In some embodiments, some or all of the backoff controllers 140 / 190 are implemented as respective link-specific backoff controllers 140 / 190 within respective LS MAC logic 316.

[0082] PHY processor 308a includes a baseband signal processor 320a corresponding to a first communication link, and PHY processor 308b includes a baseband signal processor 320b corresponding to a second communication link. PHY processor 308a also includes a first RF radio (radio-1) 328a corresponding to the first communication link, and PHY processor 308b includes a second RF radio (radio-2) 328b corresponding to the second communication link. Baseband signal processor 320a is coupled to first RF radio 328a, and baseband signal processor 320b is coupled to second RF radio 328b. In one embodiment, RF radio 328a and RF radio 328b correspond to transceiver 134 of FIG. 1. In another embodiment, RF radio 328a and RF radio 328b correspond to transceiver 174 of FIG. 1. In one embodiment, RF radio 328a is configured to operate in a first RF band and RF radio 328b is configured to operate in a second RF band, hi another embodiment, RF radio 328a and RF radio 328b are both configured to operate in the same RF band.

[0083] In one embodiment, the baseband signal processor 320 is configured to receive frames (or PSDUs) from the MAC processor 304, encapsulate the frames (or PSDUs) into respective packets, and generate respective baseband signals corresponding to the respective packets.

[0084] Baseband signal processor 320a provides each baseband signal generated by baseband signal processor 320a to radio-1 328a. Baseband signal processor 320b provides each baseband signal generated by baseband signal processor 320b to radio-2 328b. Radio-1 328a and radio-2 328b upconvert each baseband signal to generate a respective RF signal for transmission over the first and second communication links, respectively. Radio-1 328a transmits a first RF signal over a first frequency segment, and radio-2 328b transmits a second RF signal over a second frequency segment.

[0085] Additionally, radio-1 328a and radio-2 328b are configured to receive respective RF signals via the first and second communication links, respectively. Radio-1 328a and radio-2 328b generate respective baseband signals corresponding to the respective received signals. The generated respective baseband signals are provided to respective baseband signal processors 320a and 320b. Each baseband signal processor 320a and 320b generates respective PSDUs corresponding to the respective received signals and provides the respective PSDUs to MAC processor 304. In one embodiment, MAC processor 304 processes the PSDUs received from baseband signal processors 320a and 320b.

[0086] In some embodiments, the common MAC logic 312 and / or the LS MAC logic 316 are implemented, at least in part, by a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as, for example, RAM, ROM, flash memory, etc. In other embodiments, the common MAC logic 312 and / or the LS MAC logic 316 are additionally or alternatively implemented by hardware logic, such as one or more hardware state machines.

[0087] In some embodiments, the baseband signal processor 320 is implemented, at least in part, by a processor configured to execute machine-readable instructions stored in a memory device (not shown), such as, for example, RAM, ROM, flash memory, etc. In other embodiments, the baseband signal processor 320 is additionally or alternatively implemented by hardware logic, such as, for example, one or more hardware state machines, hardware calculators (e.g., FFT calculator, IFFT calculator), hardware modulators, etc.

[0088] While the example network interface 300 shown in FIG. 3 includes a single MAC processor 304, in some embodiments, other suitable network interface devices include multiple MAC processors, each corresponding to a respective communication link. While the example network interface 300 shown in FIG. 3 includes multiple PHY processors 308, in some embodiments, other suitable network interface devices include a single PHY processor, each corresponding to a respective communication link. In some embodiments, the single PHY processor includes multiple baseband processors 320, while in other embodiments, the single PHY processor includes a single baseband processor configured to generate multiple baseband signals corresponding to the respective communication links and to process multiple baseband signals received from the multiple RF radios.

[0089] 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 is not permitted within the WLAN due to, for example, physical limitations of one or more communication devices within the WLAN, channel conditions, etc.

[0090] According to one embodiment, the client station 154 informs the AP 114 whether the client station 154 can transmit and receive simultaneously over different frequency segments. For example, according to one embodiment, during the setup phase of an operating channel having multiple frequency links (which may be referred to as a "multi-link association"), the client station 154 transmits a frame (e.g., a management frame, a control frame, an action frame, etc.) to the AP 114 that includes information indicating whether the client station 154 can transmit and receive simultaneously. As another example, according to one embodiment, when joining or attempting to join a WLAN managed by multiple frequency links (which may be referred to as a "multi-link association"), the client station 154 transmits a frame (e.g., an association request frame, a reassociation request frame, a probe request frame, etc.) to the AP 114 that includes information indicating whether the client station 154 can transmit and receive simultaneously.

[0091] According to one embodiment, the AP 114 informs one or more client stations 154 whether simultaneous transmission and reception over different frequency segments is permitted within the WLAN 110. For example, according to one embodiment, during the setup phase of an operating channel having multiple frequency links (which may be referred to as a "multi-link association"), the AP 114 transmits a frame (e.g., a management frame, a control frame, an action frame, etc.) to one or more client stations 154 that includes information indicating whether simultaneous transmission and reception over different frequency segments is permitted within the WLAN 110. As another example, according to one embodiment, when a client station 154 attempts to join a WLAN 110 that is managed by multiple frequency links (which may be referred to as a "multi-link association"), the AP 114 transmits a frame (e.g., an association response frame, a reassociation response frame, a probe response frame, etc.) to the client station 154 that includes information indicating whether simultaneous transmission and reception over different frequency segments is permitted within the WLAN 110. As another example, according to one embodiment, the AP 114 periodically transmits a beacon frame that includes information indicating whether simultaneous transmission and reception over different frequency segments is permitted within the WLAN 110. As another example, according to one embodiment, if the AP 114 decides to switch from allowing simultaneous transmission and reception over different frequency segments to not allowing simultaneous transmission and reception over different frequency segments (or vice versa), the AP 114 transmits a frame (e.g., a management frame, a control frame, an action frame, etc.) that includes information indicating whether simultaneous transmission and reception over different frequency segments is permitted within the WLAN 110.

[0092] In some embodiments, if simultaneous transmission / reception in multiple frequency segments is not permitted (e.g., one or more of i) the first communication device does not permit simultaneous transmission / reception in multiple frequency segments, ii) the second communication device does not permit simultaneous transmission / reception in multiple frequency segments, iii) simultaneous transmission / reception in multiple frequency segments is not permitted in the WLAN, etc.), and the first communication device is transmitting asynchronous transmissions in the multiple frequency segments (e.g., multiple transmissions in the multiple frequency segments do not start at the same time), the first communication device simultaneously terminates the asynchronous transmissions in the multiple frequency segments. In some embodiments, if one or more of the asynchronous transmissions in the multiple frequency segments prompt another communication device to transmit an acknowledgment, simultaneously terminating the asynchronous transmissions helps avoid one communication device transmitting in one frequency segment at the same time as another communication device transmits an acknowledgment in another frequency segment.

[0093] 4 is a diagram of an example of asynchronous transmission 400 in multiple frequency segments corresponding to multiple 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 start of the transmission of the second packet 408. Thus, the transmission of the first packet 404 and the transmission of the second packet 408 begin at different times.

[0094] The first communication device receives a first acknowledgment 412 (e.g., an acknowledgment frame included in the packet, a block acknowledgment (BA) frame, etc.) in the first frequency segment in response to the first packet 404. In one embodiment, the communication device receiving the packet 404 begins transmitting the first acknowledgment 412 for a defined period of time after completing reception of the packet 404. In one embodiment, the defined period is a short interframe space (SIFS) as defined by the IEEE 802.11 standard. In other embodiments, the defined period is another suitable duration.

[0095] Similarly, the first communication device receives a second acknowledgment 416 (e.g., an acknowledgment frame, BA frame, etc. included in the packet) in the second frequency segment responsive to the second packet 408. In one embodiment, the communication device receiving the second packet 408 begins transmitting the second acknowledgment 416 for a defined period of time after completing reception of the second packet 408. In one embodiment, the defined period is a single error frame (SIFS) as defined by the IEEE 802.11 standard. In other embodiments, the defined period is another suitable duration.

[0096] To prevent the transmission of the second packet 408 from coinciding with the receipt of the acknowledgment 412, the first communications device includes padding information 420 in the packet 404 such that the end of the transmission of the packet 404 coincides with the end of the transmission of the packet 408. In the illustrative example of Figure 4, if the padding information 420 were not included in the packet 404, the receipt of the acknowledgment 412 would occur earlier than and overlap with the transmission of the packet 408. However, by including the padding information 420, the start of the receipt of the acknowledgment 412 is delayed until after the end of the transmission of the second packet 408.

[0097] In some embodiments, if multiple transmissions in each frequency segment do not prompt acknowledgments beginning a defined period (e.g., SIFS or another suitable duration) after the end of the transmission, the transmissions are allowed to end at different times, and therefore no padding, such as padding 420, is added to the packet. In other embodiments, if multiple transmissions in each frequency segment do not prompt acknowledgments beginning a defined period (e.g., SIFS or another suitable duration) after the end of the transmission, the transmissions are still required to end simultaneously.

[0098] In some embodiments, when simultaneous transmission and reception within each frequency segment is allowed, the transmissions are allowed to end at different times, and therefore no padding is added to the packets, such as padding 420. In other embodiments, even when simultaneous transmission and reception within each frequency segment is allowed, padding is added to the packets, such as padding 420, so that the transmissions end at the same time.

[0099] 4 shows an example of transmitting two packets simultaneously in two frequency segments, in other embodiments, three or more packets are transmitted simultaneously in three or more respective frequency segments. In some embodiments, padding is added to two or more packets (similar to packet 404) so ​​that transmission of all three or more packets completes simultaneously.

[0100] 5 is a flow diagram of an exemplary method 500 for simultaneously transmitting in multiple frequency segments, according to one embodiment. In some embodiments, the multiple frequency segments correspond to respective communication links. In some embodiments, the AP 114 and / or the client station 154 are 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 another suitable communication device.

[0101] At block 504, the communication device determines that simultaneous transmission and reception over multiple frequency segments is not permitted (e.g., network interface 122 determines, MAC processor 126 determines, synchronous transmission controller 146 determines, network interface 162 determines, MAC processor 166 determines, synchronous transmission controller 196 determines, etc.). For example, according to various embodiments, determining at block 504 that simultaneous transmission and reception is not permitted includes one or more (or none) of: i) determining that the communication device implementing method 400 is not permitted to transmit and receive in multiple frequency segments simultaneously; ii) determining that another communication device that will be receiving future transmissions from the communication device as part of method 400 is not permitted to transmit and receive in multiple frequency segments simultaneously; and iii) determining that simultaneous transmission and reception over multiple frequency segments is not permitted within the WLAN in which the communication device operates.

[0102] In some embodiments, determining in block 504 that simultaneous transmission and reception over multiple frequency segments is not permitted includes determining that the communications device is not permitted to transmit and receive over multiple frequency segments simultaneously. In some embodiments, determining in block 504 that simultaneous transmission and reception over multiple frequency segments is not permitted includes receiving a packet from another communications device that is transmitting to the other communications device as part of method 400, the packet including information indicating that the other communications device is not permitted to transmit and receive over multiple frequency segments simultaneously. In some embodiments, determining in block 504 that simultaneous transmission and reception over multiple frequency segments is not permitted includes receiving a packet from an AP that includes information indicating that simultaneous transmission and reception over multiple frequency segments is not permitted within a WLAN managed by the AP.

[0103] At block 508, the communications device transmits a first packet in a first frequency segment beginning at a first time (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.). At block 512, the communications device transmits a second packet in a second frequency segment beginning at a second time different from the first time (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.). The transmission of the second packet at block 512 overlaps in time with the transmission of the first packet at block 508.

[0104] At block 516, in response to determining at block 504 that simultaneous transmission and reception over multiple frequency segments is not allowed, the communications device includes (e.g., network interface 122, PHY processor 130, network interface 162, PHY processor 170, etc.) padding in the first packet such that the end of transmission of the first packet coincides with the end of transmission of the second packet. 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 such that the end of transmission of the first packet coincides 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 such that the end of transmission of the first packet coincides with the end of transmission of the second packet.

[0105] In some embodiments, if the communications device determined in block 504 that simultaneous transmission and reception over multiple frequency segments is not allowed, then the communications device does not include padding in the first packet (e.g., network interface 122 does not include it, PHY processor 130 does not include it, network interface 162 does not include it, PHY processor 170 does not include it, etc.) so that the end of transmission of the first packet coincides with the end of transmission of the second packet. 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 not include padding in the first packet so that the end of transmission of the first packet coincides with the end of transmission of the second packet. In some embodiments, padding is nevertheless added for purposes other than adding packet extension to allow a receiving device more time to generate a response to a packet, such as ensuring that the modulated information ends on an OFDM symbol boundary, ensuring that the end of transmission of a first packet occurs simultaneously with the end of transmission of a second packet, etc.

[0106] In some embodiments, communication devices within a WLAN transmit simultaneously and synchronously in multiple frequency segments, e.g., multiple transmissions in multiple frequency segments begin at the same time. In some embodiments, communication devices within a WLAN are configured to perform both i) simultaneous transmissions in multiple frequency segments, where multiple transmissions in multiple frequency segments are required to begin at the same time, and ii) simultaneous transmissions in multiple frequency segments, where multiple transmissions in multiple frequency segments are required to begin at the same time. For example, in some embodiments, at some times and / or in some situations, simultaneous transmissions in multiple frequency segments are required to begin at the same time, whereas at other times and / or in other situations, simultaneous transmissions in multiple frequency segments are allowed to begin at different times. By way of example, according to some embodiments, whether simultaneous transmissions in multiple frequency segments are required to begin at the same time depends on the frequency distance between the multiple frequency segments. For example, in an exemplary embodiment, the first frequency segment is in the 2.4 GHz band. If the second frequency segment is in the 6 GHz band, simultaneous transmissions in the multiple frequency segments are allowed to begin at different times. On the other hand, as another example, according to another exemplary embodiment, if the first frequency segment is in the 5 GHz band and the second frequency segment is in the 6 GHz band, or if the first frequency segment and the second frequency segment are in the same RF band, simultaneous transmissions in the multiple frequency segments are required to begin at the same time.

[0107] In some embodiments involving simultaneous and synchronous transmission in multiple frequency segments, the communications device performs a respective backoff operation (e.g., a respective backoff operation in each of the multiple frequency segments) (using multiple backoff counters in the multiple frequency segments) and begins simultaneous and synchronous transmission in the multiple frequency segments in response to all of the backoff counters expiring (e.g., all of the backoff counters reaching zero).

[0108] 6 is a flow diagram of an exemplary method 600 for simultaneously transmitting in multiple frequency segments beginning at the same time, according to another embodiment. In some embodiments, the multiple frequency segments correspond to respective communication links. In some embodiments, the AP 114 and / or the client station 154 are configured to implement the method 600, and FIG. 6 is described with reference to FIG. 1 for illustrative purposes only. In other embodiments, the method 600 is implemented by another suitable communication device.

[0109] At block 604, the communications device determines (e.g., by network interface 122, by MAC processor 126, by backoff controller 140, by network interface 162, by MAC processor 166, by backoff controller 190, etc.) whether multiple backoff counters (e.g., backoff counter 142, backoff counter 192, etc.) corresponding to multiple frequency segments of the operating channel have expired (e.g., reached zero). For example, in one embodiment, the communications device maintains (e.g., by network interface 122, by MAC processor 126, by backoff controller 140, by network interface 162, by MAC processor 166, by backoff controller 190, etc.) a respective backoff counter 142 / 192 for each frequency segment. In one embodiment, each backoff counter 142 / 192 corresponds to a respective subchannel within a respective frequency segment, and the backoff counter 142 / 192 is decremented when the respective subchannel is determined to be idle and suspended when the respective subchannel is determined to be busy. In one embodiment, each backoff counter 142 / 192 corresponds to a respective primary subchannel within a respective frequency segment, and the backoff counter 142 / 192 is decremented when the respective primary subchannel is determined to be idle and suspended when the respective primary subchannel is determined to be busy.

[0110] 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 communications device waits (e.g., network interface 122 waits, MAC processor 126 waits, backoff controller 140 waits, network interface 162 waits, MAC processor 166 waits, backoff controller 190 waits, etc.) until all of the multiple backoff counters have expired.

[0111] In some embodiments, if one backoff counter has expired but one or more other backoff counters have not, the method 600 includes waiting until all of the backoff counters have expired.

[0112] In response to a determination at block 604 that all of the multiple backoff counters have expired, flow proceeds to block 608. In block 608, the communications device determines whether all of the secondary subchannels in the operating channel are idle for a defined period of time before the start of transmission in the operating channel. In one embodiment, the defined period is a suitable duration, such as a Point Coordination Function (PCF) Inter-Frame Spacing (PIFS) defined by the IEEE 802.11 Standard. In other embodiments, the defined period is another suitable duration, such as a Distributed Coordination Function (DCF) Inter-Frame Spacing (DIFS) defined by the IEEE 802.11 Standard, a Single Incremental Frame Spacing (SIFS) defined by the IEEE 802.11 Standard, or another suitable duration.

[0113] In response to a determination at block 608 that not all of the secondary subchannels within the operating channel are idle (e.g., one or more of the secondary subchannels are busy) for a defined period of time prior to the start of transmission within the operating channel, flow proceeds to block 612. At block 612, no transmission is performed within the operating channel. In some embodiments, in connection with block 612, multiple back-off counters are reset and flow 600 is repeated. In another embodiment, transmission is performed i) within multiple primary subchannels corresponding to the multiple back-off counters and ii) within one or more secondary subchannels (if any) that are idle.

[0114] On the other hand, in response to a determination at block 608 that all of the secondary subchannels within the operating channel are idle (e.g., one or more of the secondary subchannels are busy) for a defined period of time prior to the start of transmission within the operating channel, flow proceeds to block 616. At block 616, transmission within the operating channel is performed, which includes transmitting simultaneously within multiple frequency segments beginning at the same time.

[0115] 7 is a diagram of an illustrative example of simultaneous transmission in multiple frequency segments starting at the same time, according to one embodiment. In some embodiments, transmission 700 is performed according to method 600 of FIG. 6. In other embodiments, transmission 700 is performed according to another suitable method of simultaneous transmission in multiple frequency segments starting at the same time.

[0116] The transmission 700 is within an operating channel that includes 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.

[0117] A first backoff procedure 704 is performed by the communication device in association with a 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), and a second backoff procedure 708 is performed by the communication device in association with a 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.).

[0118] In some embodiments, performing the backoff procedure 704 includes decrementing a first backoff counter if a subchannel in the first frequency segment is determined to be idle and suspending decrementing of the first backoff counter if a subchannel in the first frequency segment is determined to be not idle (e.g., busy). In some embodiments, performing the backoff procedure 704 includes decrementing a first backoff counter if a primary subchannel in the first frequency segment is determined to be idle and suspending decrementing of the first backoff counter if a primary subchannel in the first frequency segment is determined to be not idle (e.g., busy).

[0119] In some embodiments, performing the backoff procedure 708 includes decrementing a second backoff counter if a subchannel in the second frequency segment is determined to be idle and suspending decrementing of the second backoff counter if a subchannel in the second frequency segment is determined to be not idle (e.g., busy). In some embodiments, performing the backoff procedure 708 includes decrementing a second backoff counter if a primary subchannel in the second frequency segment is determined to be idle and suspending decrementing of the second backoff counter if a primary subchannel in the second frequency segment is determined to be not idle (e.g., busy).

[0120] 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 communications device postpones transmission in the first frequency segment (e.g., waits to transmit) until the second backoff counter expires. In response to the second backoff counter expiring, the communications device transmits a transmission 720 (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.) including a first transmission 724 in the first frequency segment and a second transmission 728 in the second frequency segment. The first transmission 724 and the second transmission 728 begin simultaneously.

[0121] 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 the operating channel.

[0122] 8 is a diagram of another illustrative example of simultaneous transmission in multiple frequency segments starting at the same time, according to another embodiment. In some embodiments, transmission 800 is performed according to method 600 of FIG. 6. In other embodiments, transmission 800 is performed according to another suitable method of simultaneous transmission in multiple frequency segments starting at the same time.

[0123] The transmission 800 is within an operating channel that includes 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.

[0124] Transmission 800 is similar to transmission 700 of FIG. 7, and like-numbered elements will not be described in detail for the sake of brevity.

[0125] In response to the first backoff counter expiring before the second backoff counter expiry, the communications device postpones (e.g., waits to transmit) transmission 724 until the second backoff counter expires and transmits padding signal 804. In response to the second backoff counter expiring, the communications device stops transmitting padding signal 804 and begins transmitting transmission 720 (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.) including a first transmission 724 in a first frequency segment and a second transmission 728 in a second frequency segment. In one embodiment, transmission 724 includes a PHY preamble having a training field (e.g., a legacy short training field (L-STF)) or another suitable training field used by a receiver for, among other things, packet detection. In some embodiments, the padding signal 804 has low cross-correlation with a training field in the PHY preamble used by the receiver for packet detection, such that the receiver is less likely to mistake the padding signal 804 for the start of a packet. Additionally or alternatively, according to some embodiments, the padding signal 804 is configured to prompt the receiving device to determine that the subchannel on which the padding signal 804 is transmitted is busy, thereby increasing the probability that other communication devices will not attempt to transmit in the subchannel corresponding to the first transmission 724 between the time the first back-off counter expires and the time the second back-off counter expires.

[0126] 7 and 8 show exemplary simultaneous transmissions in two frequency segments, in other embodiments, three or more transmissions are transmitted simultaneously in three or more respective frequency segments. With respect to FIG. 8, in some embodiments, padding is transmitted in two or more frequency segments.

[0127] 6-8, according to one embodiment, when a frame transmission in one frequency segment fails in association with simultaneous transmissions in multiple frequency segments (e.g., when an acknowledgment for the frame is not received), the value of CW is adjusted (e.g., approximately doubled, up to a limit of CWmax) for only one of the back-off counters (e.g., the value of CW for one or more other back-off counters remains the same). According to one embodiment, when a frame transmission in one frequency segment fails in association with simultaneous transmissions in multiple frequency segments (e.g., when an acknowledgment for the frame is not received), the value of CW is adjusted (e.g., approximately doubled, up to a limit of CWmax) for only the back-off counter corresponding to the one frequency segment (e.g., the value of CW for one or more other back-off counters remains the same). In another embodiment, when a frame transmission in one frequency segment fails in association with simultaneous transmissions in multiple frequency segments (e.g., when an acknowledgment for the frame is not received), the value of CW is adjusted (e.g., approximately doubled, up to a limit of CWmax) for all of the back-off counters.

[0128] 9 is a flow diagram of another exemplary method 900 of simultaneously transmitting in multiple frequency segments beginning at the same time, according to another embodiment. In some embodiments, the multiple frequency segments correspond to respective communication links. In some embodiments, the AP 114 and / or the client station 154 are configured to implement the method 900, and FIG. 9 is described with reference to FIG. 1 for illustrative purposes only. In other embodiments, the method 900 is implemented by another suitable communication device.

[0129] At block 904, the communications device determines (e.g., network interface 122 determines, MAC processor 126 determines, backoff controller 140 determines, network interface 162 determines, MAC processor 166 determines, backoff controller 190 determines, etc.) 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 zero). In one embodiment, backoff counter 142 / 192 corresponds to a subchannel within a single frequency segment, and backoff counter 142 / 192 is decremented if the subchannel is determined to be idle and ceases decrementing if the subchannel is determined to be 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 the primary subchannel is determined to be idle and ceases decrementing when the primary subchannel is determined to be busy.

[0130] In response to a determination in block 904 that the single backoff counter has not expired, the communications device waits (e.g., network interface 122 waits, MAC processor 126 waits, backoff controller 140 waits, network interface 162 waits, MAC processor 166 waits, backoff controller 190 waits, etc.) until the single backoff counter expires.

[0131] In response to a determination at block 904 that a single backoff counter has expired, flow proceeds to block 908. At block 908, the communications device determines whether all of the other subchannels within the operating channel (e.g., subchannels other than the primary subchannel corresponding to the backoff counter) are idle for a defined period of time prior to the start of transmission within the operating channel. In one embodiment, the defined period is a suitable duration, such as a PIFS as defined by the IEEE 802.11 standard. In other embodiments, the defined period is another suitable duration, such as a DIFS as defined by the IEEE 802.11 standard, a SIFS as defined by the IEEE 802.11 standard, or another suitable duration.

[0132] In response to a determination at block 908 that not all of the other sub-channels within the operating channel are idle (e.g., one or more of the other sub-channels are busy) for a defined period of time prior to the initiation of transmission within the operating channel, flow proceeds to block 912. At block 912, no transmission is performed within the operating channel. In some embodiments, in connection with block 912, a single back-off counter is reset and flow 900 is repeated. In another embodiment, transmission is performed i) within the primary sub-channel corresponding to the back-off counter and ii) within one or more other sub-channels (if any) that are idle.

[0133] On the other hand, in response to a determination at block 908 that all of the other subchannels in the operating channel are idle (e.g., one or more of the secondary subchannels are busy) for a defined period of time prior to the start of transmission in the operating channel, flow proceeds to block 916. At block 916, transmission in the operating channel is performed, which includes transmitting simultaneously in multiple frequency segments starting at the same time.

[0134] 10 is a diagram of an illustrative example of simultaneous transmissions in multiple frequency segments beginning at the same time, according to one embodiment. In some embodiments, transmissions 1000 are performed according to method 900 of FIG. 9. In other embodiments, transmissions 1000 are performed according to another suitable method of simultaneous transmissions in multiple frequency segments beginning at the same time.

[0135] The transmission 1000 is within an operating channel that includes 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.

[0136] A backoff procedure 1004 is performed by the communications device (e.g., by network interface 122, by MAC processor 126, by backoff controller 140, by network interface 162, by MAC processor 166, by backoff controller 190, etc.) in association with the first frequency segment. In some embodiments, performing the backoff procedure 1004 includes decrementing a backoff counter if a subchannel in the first frequency segment is determined to be idle and suspending decrementing of the backoff counter if a subchannel in the first frequency segment is determined to be not idle (e.g., busy). In some embodiments, performing the backoff procedure 1004 includes decrementing a backoff counter if a primary subchannel in the first frequency segment is determined to be idle and suspending decrementing of the backoff counter if a primary subchannel in the first frequency segment is determined to be not idle (e.g., busy).

[0137] In response to the backoff counter expiring, the communications device transmits a transmission 1020 (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.) that includes a first transmission 1024 in a first frequency segment and a second transmission 1028 in a second frequency segment. The first transmission 1024 and the second transmission 1028 begin simultaneously.

[0138] In one 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 the operating channel.

[0139] In some embodiments, the frequency segments on which the backoff procedure is performed for transmissions beginning simultaneously on the multiple frequency segments are changed over time. For example, in some embodiments, in connection with a first transmission within the multiple frequency segments, the communications device selects a frequency segment from the multiple frequency segments for which to perform a different backoff procedure than another frequency segment in which a backoff procedure was used for a previous second transmission over the multiple frequency segments.

[0140] 11 is a diagram of an illustrative example of multiple sets of simultaneous transmissions 1100 according to one embodiment. In some embodiments, each of the sets of transmissions in the multiple sets of transmissions 1100 is performed according to method 900 of FIG. 9. In other embodiments, each of the sets of transmissions in the multiple sets of transmissions 1100 is performed according to another suitable method of simultaneously transmitting in multiple frequency segments starting at the same time.

[0141] The set of transmissions 1100 is within an operating channel that includes 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.

[0142] In association with the first transmission set 1104, the communications device performs a backoff procedure 1108 in association with the first frequency segment (e.g., performed by network interface 122, performed by MAC processor 126, performed by backoff controller 140, performed by network interface 162, performed by MAC processor 166, performed by backoff controller 190, etc.). In some embodiments, performing the backoff procedure 1108 includes decrementing a backoff counter if a subchannel in the first frequency segment is determined to be idle and suspending decrementing of the backoff counter if a subchannel in the first frequency segment is determined to be not idle (e.g., busy). In some embodiments, performing the backoff procedure 1108 includes decrementing a backoff counter if a primary subchannel in the first frequency segment is determined to be idle and suspending decrementing of the backoff counter if a primary subchannel in the first frequency segment is determined to be not idle (e.g., busy).

[0143] In response to the backoff counter expiring, the communications device transmits a set of transmissions 1104 (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.) that includes a first transmission 1124 in a first frequency segment and a second transmission 1128 in a second frequency segment. The first transmission 1124 and the second transmission 1128 begin simultaneously.

[0144] 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 the operating channel.

[0145] In association with the second transmission set 1134, the communications device performs a backoff procedure 1138 in association with the second frequency segment (e.g., performed by network interface 122, performed by MAC processor 126, performed by backoff controller 140, performed by network interface 162, performed by MAC processor 166, performed by backoff controller 190, etc.). In some embodiments, performing the backoff procedure 1138 includes decrementing a backoff counter if a subchannel in the second frequency segment is determined to be idle and suspending decrementing of the backoff counter if a subchannel in the second frequency segment is determined to be not idle (e.g., busy). In some embodiments, performing the backoff procedure 1138 includes decrementing a backoff counter if a primary subchannel in the second frequency segment is determined to be idle and suspending decrementing of the backoff counter if a primary subchannel in the second frequency segment is determined to be not idle (e.g., busy).

[0146] In response to the backoff counter expiring, the communications device transmits a set of transmissions 1134 (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.) that includes a first transmission 1144 in a first frequency segment and a second transmission 1148 in a second frequency segment. The first transmission 1144 and the second transmission 1148 begin simultaneously.

[0147] 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 the operating channel.

[0148] In association with the third transmission set 1154, the communications device performs a backoff procedure 1158 in association with the first frequency segment (e.g., performed by network interface 122, performed by MAC processor 126, performed by backoff controller 140, performed by network interface 162, performed by MAC processor 166, performed by backoff controller 190, etc.). In some embodiments, performing the backoff procedure 1158 includes decrementing a backoff counter if a subchannel in the first frequency segment is determined to be idle and suspending decrementing of the backoff counter if a subchannel in the first frequency segment is determined to be not idle (e.g., busy). In some embodiments, performing the backoff procedure 1158 includes decrementing a backoff counter if a primary subchannel in the first frequency segment is determined to be idle and suspending decrementing of the backoff counter if a primary subchannel in the first frequency segment is determined to be not idle (e.g., busy).

[0149] In response to the backoff counter expiring, the communications device transmits a set of transmissions 1154 (e.g., network interface 122 transmits, PHY processor 130 transmits, network interface 162 transmits, PHY processor 170 transmits, etc.) that includes a first transmission 1164 in a first frequency segment and a second transmission 1168 in a second frequency segment. The first transmission 1164 and the second transmission 1168 begin simultaneously.

[0150] 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 the operating channel.

[0151] 10 and 11 show exemplary simultaneous transmissions in two frequency segments, in other embodiments, three or more transmissions are transmitted simultaneously in three or more respective frequency segments. With respect to FIG. 11, in some embodiments, backoff operations are performed in three or more frequency segments.

[0152] 9-11 illustrate performing a backoff operation within only one frequency segment using only one backoff counter. In some embodiments, a communications device maintains multiple backoff counters for multiple frequency segments (e.g., network interface 122 maintains, MAC processor 126 maintains, backoff controller 140 maintains, network interface 162 maintains, MAC processor 166 maintains, and backoff controller 190 maintains), and backoff counters corresponding to other frequency segments are ignored when at least one 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 described 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 described 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, if another backoff counter corresponding to another frequency segment expires, the value of CW remains the same and the other backoff counter is reset, as described above.

[0153] 9-11 , according to one embodiment, when a frame transmission in one frequency segment fails in association with simultaneous transmissions in multiple frequency segments (e.g., when an acknowledgment for the frame is not received), the value of CW is adjusted (e.g., approximately doubled, up to a cap of CWmax) for only one of the back-off counters (e.g., the value of CW for one or more other back-off counters remains the same). According to one embodiment, when a frame transmission in one frequency segment fails in association with simultaneous transmissions in multiple frequency segments (e.g., when an acknowledgment for the frame is not received), the value of CW is adjusted (e.g., approximately doubled, up to a cap of CWmax) for only the back-off counter corresponding to the one frequency segment (e.g., the value of CW for one or more other back-off counters remains the same). In another embodiment, when a frame transmission in one frequency segment fails in association with simultaneous transmissions in multiple frequency segments (e.g., when an acknowledgment for the frame is not received), the value of CW is adjusted (e.g., approximately doubled, up to a cap of CWmax) for all of the back-off counters.

[0154] In various embodiments described above, the communication device determines whether a subchannel is idle by comparing an energy level measured in the subchannel with a threshold. In some embodiments, additionally or alternatively, the communication device determines whether a subchannel is idle by determining whether a network allocation vector (NAV) counter corresponding to the subchannel has expired (e.g., network interface 122 determines, MAC processor 126 determines, backoff controller 140 determines, network interface 162 determines, MAC processor 166 determines, backoff controller 190 determines, etc.). In some embodiments, the NAV counter indicates whether another communication device has control of the communication medium. For example, the NAV counter is set using duration information in a received frame, and the NAV counter is decremented at a predetermined rate. If the NAV counter has expired (e.g., reached zero), this indicates that no other communication device is currently in control of the communication medium.

[0155] Embodiment 1: A method of simultaneously transmitting in multiple frequency segments, the method comprising: determining, at a communication device, that simultaneous transmission and reception over multiple frequency segments is not permitted; transmitting, by the communication device, a first packet in a first frequency segment beginning at a first time; transmitting, by the communication device, a second packet in a second frequency segment beginning at a second time different from the first time, the transmission of the second packet overlapping in time with the transmission of the first packet; and, in response to determining that simultaneous transmission and reception over multiple frequency segments is not permitted, including padding in the first packet such that an end of transmission of the first packet occurs simultaneously with an end of transmission of the second packet.

[0156] Embodiment 2: The method of embodiment 1, wherein determining that simultaneous transmission and reception over multiple frequency segments is not permitted comprises determining that the communication device is not permitted to transmit and receive over multiple frequency segments simultaneously.

[0157] Embodiment 3: The method of embodiment 1, wherein the communication device is a first communication device, and transmitting the second packet in the second frequency segment comprises transmitting the second packet to a second communication device in the second frequency segment, and determining that simultaneous transmission and reception over multiple frequency segments is not permitted comprises determining that the second communication device is not permitted to transmit and receive over multiple frequency segments simultaneously.

[0158] Embodiment 4: The method of embodiment 3, wherein the second communication device is not authorized to transmit and receive simultaneously over multiple frequency segments, includes receiving at the first communication device a third packet from the second communication device, the third packet including information indicating that the second communication device is not authorized to transmit and receive simultaneously over multiple frequency segments.

[0159] Embodiment 5: The method of embodiment 1, wherein determining that simultaneous transmission and reception over multiple frequency segments is not permitted includes determining that simultaneous transmission and reception over multiple frequency segments is not permitted within a wireless local area network (WLAN) to which the communication device belongs.

[0160] Embodiment 6: The method of embodiment 5, wherein determining that simultaneous transmission and reception over multiple frequency segments is not permitted within the WLAN includes receiving at the communication device a third packet from an access point managing the WLAN, the third packet including information indicating that simultaneous transmission and reception over multiple frequency segments is not permitted within the WLAN.

[0161] Embodiment 7: The method of any one of embodiments 1 to 6, further comprising, in response to determining that simultaneous transmission and reception over multiple frequency segments is not permitted, prompting a physical layer (PHY) processor of the communication device to include the padding in the first packet such that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet.

[0162] Embodiment 8: A first communications device comprising a wireless network interface device configured to communicate over multiple frequency segments, the wireless network interface device having one or more integrated circuit (IC) devices configured to: determine that simultaneous transmission and reception over multiple frequency segments are not permitted; control the wireless network interface device to transmit a first packet in a first frequency segment beginning at a first time; and control the wireless network interface device to transmit a second packet in a second frequency segment beginning at a second time different from the first time, wherein transmission of the second packet overlaps in time with transmission of the first packet; and, in response to determining that simultaneous transmission and reception over multiple frequency segments are not permitted, include padding in the first packet such that an end of transmission of the first packet occurs simultaneously with an end of transmission of the second packet.

[0163] Embodiment 9: The first communication device described in embodiment 8, wherein the one or more IC devices are configured to determine that the first communication device is not authorized to transmit and receive simultaneously over multiple frequency segments.

[0164] Embodiment 10: The first communication device described in embodiment 8, wherein the one or more IC devices are configured to: control the wireless network interface device to transmit the second packet to a second communication device in the second frequency segment; and determine that simultaneous transmission and reception over multiple frequency segments is not permitted by at least determining that the second communication device is not permitted to transmit and receive over multiple frequency segments simultaneously.

[0165] Embodiment 11: The first communication device described in embodiment 10, wherein the one or more IC devices are configured to perform the following: determine, using information in a third packet received from the second communication device, that the second communication device is not authorized to transmit and receive simultaneously over multiple frequency segments, wherein the information in the third packet indicates that the second communication device is not authorized to transmit and receive simultaneously over multiple frequency segments.

[0166] Embodiment 12: The first communication device described in embodiment 8, wherein the one or more IC devices are configured to perform at least the following: determine that simultaneous transmission and reception over multiple frequency segments is not permitted by determining that simultaneous transmission and reception over multiple frequency segments is not permitted within a WLAN to which the communication device belongs.

[0167] Embodiment 13: The first communication device described in embodiment 12, wherein the one or more IC devices are configured to perform the following: determine, using information in a third packet received from an access point managing the WLAN, that simultaneous transmission and reception over multiple frequency segments is not permitted within the WLAN, wherein the information in the third packet indicates that simultaneous transmission and reception over multiple frequency segments is not permitted within the WLAN.

[0168] Embodiment 14: A first communication device as described in any of embodiments 8 to 13, wherein the wireless network interface has a physical layer (PHY) processor implemented on the 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 so that the end of transmission of the first packet occurs simultaneously with the end of transmission of the second packet in response to a determination that simultaneous transmission and reception over multiple frequency segments is not permitted.

[0169] Embodiment 15: A method for simultaneously transmitting in multiple frequency segments, the method comprising: performing, at a communication device, a backoff operation corresponding to one frequency segment among the multiple frequency segments, the backoff operation involving decrementing a backoff counter associated with the one frequency segment; determining, at the communication device, whether the backoff counter of the communication device has expired; and, in response to determining that the backoff counter has expired, the communication device simultaneously transmitting respective transmissions in the respective frequency segments starting at the same time.

[0170] Embodiment 16: The method of embodiment 15, further comprising: the communication device decrementing the back-off counter when a subchannel in the one frequency segment is determined to be idle; and the communication device ceasing the decrementing of the back-off counter when the subchannel in the one frequency segment is determined to be busy.

[0171] Embodiment 17: The method of embodiment 16, further comprising a step of determining at the communication device whether one or more other subchannels in the plurality of frequency segments are idle for a predetermined period of time prior to the start of the respective transmission in the respective frequency segment in connection with determining that the backoff counter has expired, wherein the step of simultaneously transmitting the respective transmissions in the respective frequency segments starting at the same time is further responsive to a determination that the one or more other subchannels in the plurality of frequency segments are idle for the predetermined period of time.

[0172] Embodiment 18: The method of embodiment 17, further comprising determining to postpone the simultaneous transmission of the respective transmissions in the respective frequency segments in response to determining that one or more other subchannels in the plurality of frequency segments are busy during the predetermined period.

[0173] Embodiment 19: The method of any one of embodiments 15 to 18, further comprising: selecting, in the communication device, another frequency segment different from the one frequency segment in association with subsequent simultaneous transmissions in a plurality of frequency segments; performing, in the communication device, 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 another backoff counter in association with the other frequency segment; determining, in the communication device, whether the backoff counter or the other backoff counter has expired; and performing, in response to determining that the backoff counter or the other backoff counter has expired, the communication device performing the subsequent simultaneous transmissions in the plurality of frequency segments.

[0174] Embodiment 20: The method of any of embodiments 15 to 18, in combination with the method of any of embodiments 1 to 7.

[0175]

[0072] Embodiment 21: A communications device comprising: a wireless network interface device configured to communicate over a plurality of frequency segments, the wireless network interface device having one or more IC devices and a back-off counter implemented on the one or more IC devices, the one or more IC devices configured to: perform a back-off operation corresponding to a frequency segment among the plurality of frequency segments, the back-off operation involving decrementing the back-off counter associated with the frequency segment; determine whether the back-off counter has expired; and, in response to determining that the back-off counter has expired, control the wireless network interface device to simultaneously transmit respective transmissions in the respective frequency segments starting at the same time.

[0176] Embodiment 22: The communications device of embodiment 21, wherein the one or more IC devices are further configured to decrement the back-off counter when a subchannel in the one frequency segment is determined to be idle, and to discontinue the decrementing of the back-off counter when the subchannel in the one frequency segment is determined to be busy.

[0177] Embodiment 23: The communications device of embodiment 22, wherein the one or more IC devices are further configured to: determine, in conjunction with determining that the backoff counter has expired, whether one or more other subchannels in the plurality of frequency segments are idle for a predetermined period prior to the start of the respective transmission in the respective frequency segment; and, further in response to determining that the one or more other subchannels in the plurality of frequency segments are idle for the predetermined period, control the wireless network interface device to simultaneously transmit the respective transmission in the respective frequency segment.

[0178] Embodiment 24: The communication device of embodiment 23, wherein the one or more IC devices are further configured to execute a determination to postpone the simultaneous transmission of the respective transmissions in the respective frequency segments in response to determining that one or more other subchannels in the plurality of frequency segments are busy during the predetermined period.

[0179] Embodiment 25: The communications device of any of embodiments 21 to 24, wherein the one or more IC devices are further configured to: select another frequency segment different from the one frequency segment in association with a subsequent simultaneous transmission within a plurality of frequency segments; perform another backoff operation corresponding to the other frequency segment different from the one frequency segment, the other backoff operation including decrementing the backoff counter or another backoff counter in association with the other frequency segment; determine whether the backoff counter or the other backoff counter has expired; and control the wireless network interface device to perform the subsequent simultaneous transmission within the plurality of frequency segments in response to a determination that the backoff counter or the other backoff counter has expired.

[0180] Embodiment 26: A communication device described in any of embodiments 21 to 25, wherein the one or more IC devices are further configured to perform the operations described in any of embodiments 8 to 14.

[0181] 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, for example, random access memory (RAM), read-only memory (ROM), flash memory, etc. The software or firmware instructions may include machine-readable instructions that, when executed by one or more processors, cause the one or more processors to perform various operations.

[0182] When implemented in hardware, the hardware may comprise one or more of discrete components, an integrated circuit, an application specific integrated circuit (ASIC), a programmable logic device (PLD), and so on.

[0183] While the present invention has been described with reference to specific examples, these examples are intended to be illustrative only and not limiting of the invention, and modifications, additions and / or deletions may be made to the disclosed embodiments without departing from the scope of the invention.

Claims

1. determining, at a communication device, that the communication device transmits in a first frequency segment simultaneously with transmitting in a second frequency segment; performing a first backoff operation at the communication device using a first backoff counter to determine when to transmit a first packet in the first frequency segment, the first backoff counter expiring to indicate the expiration of a first contention window; performing a second backoff operation at the communication device using a second backoff counter to determine when to transmit a second packet in the second frequency segment, the second backoff counter expiring to indicate the expiration of a second contention window; transmitting, by the communications device, the first packet in the first frequency segment in association with the first backoff counter expiring; transmitting the second packet in the second frequency segment by the communications device simultaneously with transmitting the first packet in the first frequency segment in association with the second back-off counter expiring; In response to determining that transmission of the first packet in the first frequency segment failed, at the communications device: the communication device increasing the first contention window for retransmission of the first packet in the first frequency segment; the communication device not adjusting the second contention window for a next transmission in the second frequency segment; 1. A method of communication in a wireless local area network (WLAN), comprising:

2. Increasing the first contention window for the retransmission of the first packet within the first frequency segment comprises doubling the first contention window. The method of communication according to claim 1 .

3. The step of performing the first backoff operation includes: the communications device decrementing the first back-off counter when a first subchannel in the first frequency segment is determined to be idle; the communication device ceasing the decrementing of the first back-off counter when the first subchannel in the first frequency segment is determined to be busy; The step of performing the second backoff operation includes: the communications device decrementing the second back-off counter when a second subchannel in the second frequency segment is determined to be idle; and the communication device ceasing the decrementing of the second back-off counter when the second subchannel in the second frequency segment is determined to be busy. The method of communication according to claim 1 .

4. determining, in conjunction with determining that the first back-off counter has expired, at the communications device whether one or more other sub-channels in the first frequency segment are idle for a predetermined period of time prior to initiating the transmission of the first packet in the first frequency segment; determining, in conjunction with determining that the second back-off counter has expired, at the communications device whether one or more other sub-channels in the second frequency segment are idle for the predetermined period prior to initiating the transmission of the second packet in the second frequency segment; Furthermore, transmitting the first packet in the first frequency segment in response to determining that the one or more other subchannels in the first frequency segment are idle for the predetermined period of time; transmitting the second packet in the second frequency segment in response to determining that the one or more other subchannels in the second frequency segment are idle for the predetermined period of time. The method of communication according to claim 1 .

5. determining that the communication device transmits in the first frequency segment simultaneously with transmitting in the second frequency segment, determining that the communication device transmits in the first frequency segment while also transmitting in the second frequency segment; transmitting the first packet in the first frequency segment and simultaneously transmitting the second packet in the second frequency segment includes: transmitting the second packet in the second frequency segment while the communication device transmits the first packet in the first frequency segment. A method of communication according to any one of claims 1 to 4.

6. Transmitting the first packet includes commencing transmission of the first packet at a first time; transmitting the second packet includes commencing transmission of the second packet at a second time different from the first time. The method of communication according to claim 5.

7. determining, in the communications device, that the communications device synchronizes a start of a first transmission in the first frequency segment with a start of a second transmission in the second frequency segment; transmitting the second packet in the second frequency segment simultaneously with transmitting the first packet in the first frequency segment includes synchronizing a start of transmission of the second packet in the second frequency segment with a start of transmission of the first packet in the first frequency segment. A method of communication according to any one of claims 1 to 4.

8. Transmitting the first packet in the first frequency segment comprises: the communication device waiting for the second back-off counter to expire before transmitting the first packet in the first frequency segment. A method of communication according to any one of claims 1 to 4.

9. determining, at the communications device, to synchronize an end of a first transmission in the first frequency segment with an end of a second transmission in the second frequency segment; transmitting the second packet in the second frequency segment simultaneously with transmitting the first packet in the first frequency segment includes synchronizing an end of transmission of the second packet in the second frequency segment with an end of transmission of the first packet in the first frequency segment. A method of communication according to any one of claims 1 to 4.

10. synchronizing the end of the transmission of the second packet in the second frequency segment with the end of the transmission of the first packet in the first frequency segment, adding padding to the second packet such that the end of the transmission of the second packet in the second frequency segment corresponds to the end of the transmission of the first packet in the first frequency segment.

10. The method of communication of claim 9.

11. 1. A communications device comprising: a wireless network interface device for communicating in a plurality of frequency segments, the wireless network interface device including: one or more integrated circuit (IC) devices; and a plurality of backoff counters implemented on the one or more integrated circuit devices; the one or more integrated circuit devices determining that the communication device transmits in a first frequency segment simultaneously with transmitting in a second frequency segment; performing a first backoff operation using a first backoff counter of the plurality of backoff counters to determine when to transmit a first packet in the first frequency segment, the expiration of the first backoff counter indicating expiration of a first contention window; performing a second backoff operation using a second backoff counter of the plurality of backoff counters to determine when to transmit a second packet in the second frequency segment, the second backoff counter expiring to indicate the expiration of a second contention window; controlling the wireless network interface device to transmit the first packet in the first frequency segment in association with the first backoff counter expiring; controlling the radio network interface device to transmit the second packet in the second frequency segment simultaneously with transmitting the first packet in the first frequency segment in association with the second back-off counter expiring; in response to determining that transmission of the first packet in the first frequency segment has failed; increasing the first contention window for retransmission of the first packet in the first frequency segment; not adjusting the second contention window for a next transmission in the second frequency segment. It is configured as follows: Communication devices.

12. the one or more integrated circuit devices configured to increase the first contention window by doubling the first contention window for the retransmission of the first packet in the first frequency segment.

12. The communication device of claim 11.

13. the one or more integrated circuit devices As part of performing the first backoff operation, decrementing the first backoff counter when a first subchannel in the first frequency segment is determined to be idle; ceasing the decrementing of the first back-off counter when the first subchannel in the first frequency segment is determined to be busy; As part of performing the second backoff operation. decrementing the second backoff counter when a second subchannel in the second frequency segment is determined to be idle; and further configured to suspend the decrementing of the second back-off counter when the second subchannel in the second frequency segment is determined to be busy.

12. The communication device of claim 11.

14. the one or more integrated circuit devices In conjunction with determining that the first back-off counter has expired, determining whether one or more other sub-channels in the first frequency segment are idle for a predetermined period of time prior to the start of the transmission of the first packet in the first frequency segment; In conjunction with determining that the second back-off counter has expired, determining whether one or more other sub-channels in the second frequency segment are idle for the predetermined period of time prior to the start of the transmission of the second packet in the second frequency segment; controlling the wireless network interface device to transmit the first packet in the first frequency segment in response to determining that the one or more other sub-channels in the first frequency segment are idle for the predetermined period of time; and controlling the wireless network interface device to transmit the second packet in the second frequency segment in response to determining that the one or more other sub-channels in the second frequency segment are idle for the predetermined period of time. further configured as follows:

12. The communication device of claim 11.

15. the one or more integrated circuit devices determining that the communication device transmits in the first frequency segment while also transmitting in the second frequency segment as part of determining that the communication device transmits in the first frequency segment simultaneously with transmitting in the second frequency segment; As part of controlling the wireless network interface device to transmit the first packet in the first frequency segment and simultaneously transmit the second packet in the second frequency segment, controlling the wireless network interface device to transmit the second packet in the second frequency segment while the communication device transmits the first packet in the first frequency segment; further configured as follows: A communication device according to any one of claims 11 to 14.

16. the one or more integrated circuit devices controlling the wireless network interface device to begin transmitting the first packet at a first time; controlling the wireless network interface device to begin transmitting the second packet at a second time different from the first time; further configured as follows:

16. The communication device of claim 15.

17. the one or more integrated circuit devices determining that the communications device synchronizes a start of a first transmission in the first frequency segment to a start of a second transmission in the second frequency segment; As part of controlling the wireless network interface device to transmit the first packet in the first frequency segment and simultaneously transmit the second packet in the second frequency segment, Synchronizing a start of transmission of the second packet in the second frequency segment with a start of transmission of the first packet in the first frequency segment. further configured as follows: A communication device according to any one of claims 11 to 14.

18. the one or more integrated circuit devices and controlling the wireless network interface device to wait for the second back-off counter to expire before transmitting the first packet in the first frequency segment. A communication device according to any one of claims 11 to 14.

19. the one or more integrated circuit devices determining that the communications device synchronizes an end of a first transmission in the first frequency segment to an end of a second transmission in the second frequency segment; As part of controlling the wireless network interface device to transmit the first packet in the first frequency segment and simultaneously transmit the second packet in the second frequency segment, further configured to synchronize an end of transmission of the second packet in the second frequency segment with an end of transmission of the first packet in the first frequency segment. A communication device according to any one of claims 11 to 14.

20. the one or more integrated circuit devices As part of synchronizing the end of the transmission of the second packet in the second frequency segment with the end of the transmission of the first packet in the first frequency segment, configured to add padding to the second packet such that the end of the transmission of the second packet in the second frequency segment corresponds to the end of the transmission of the first packet in the first frequency segment.

20. The communication device of claim 19.

21. the wireless network interface device having a plurality of transceivers configured to transmit and receive within respective frequency segments; a first transceiver configured to transmit and receive within the first frequency segment; and a second transceiver configured to transmit and receive within the second frequency segment; A communication device according to any one of claims 11 to 14.

22. 22. The communications device of claim 21, further comprising one or more antennas coupled to the plurality of transceivers.

23. further comprising a host processor coupled to the wireless network interface device; A communication device according to any one of claims 11 to 14.

24. further comprising one or more antennas coupled to the wireless network interface device.

24. The communication device of claim 23.

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