Access point, communication method, and integrated circuit

Abstract

To provide a communication device for enhanced direct link communication.SOLUTION: A communication device is configured to wirelessly communicate with an AP (Access Point) on a first channel. The communication device includes: a circuit that, in operation, generates a channel use permission request frame including information indicating the communication device, another communication device, and a second channel different from the first channel; a transmitter that, in operation, transmits the generated channel use permission request frame to the AP to request permission from the AP to use the second channel for direct link communication with the other communication device; and a receiver that, in operation, receives a channel use permission response frame that permits use of the second channel from the AP. The communication device is further configured to communicate with the other communication device on a direct link on the second channel after receiving the channel use permission response frame.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present disclosure relates to a communication device and a communication method for enhanced direct link communication, and more particularly to a communication device and a communication method for enhanced direct link communication in a regulated band such as the 6 GHz band. [Background technology]

[0002] Recently, the FCC (Federal Communications Commission) opened up the 6 GHz band for unlicensed use, which will play a key role in achieving the throughput targets of upcoming wireless standards such as IEEE 802.11ax (HE), IEEE 802.11be (EHT), and 3GPP's 5G standard.

[0003] To protect existing users, the FCC is proposing the following rules in its latest NPRM (Notice for Proposed Rulemaking): The U-NII-5 and U-NII-7 subbands are heavily used by point-to-point microwave links, including those that must maintain a high level of availability. As such, only "standard power access points" (APs) using power levels in the U-NII-1 and U-NII-3 bands can operate in these subbands, on frequencies determined by the Automated Frequency Coordination (AFC) system. U-NII stands for Unlicensed National Information Infrastructure. The U-NII-6 and U-NII-8 subbands are used by mobile stations in locations where the location of existing receivers cannot be easily determined from existing databases and where the use of AFC is difficult. Therefore, only indoor "low-power access points" using the lower power levels of the U-NII-2 band may be permitted in these subbands. Client devices may be allowed to operate across the entire 6 GHz band under the control of either standard-power APs or low-power APs.

[0004] However, communication devices and methods for direct link communication in the 6 GHz band have not been discussed so far. In particular, in the U-NII-5 and U-NII-7 subbands, devices may not be directly connected to the AFC system, so it is unclear how devices involved in direct link communication may operate.

[0005] Therefore, what is needed is a communication apparatus and method that provides a viable technical solution for extended direct link communication in the 6 GHz band. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure. Summary of the Invention

[0006] Non-limiting examples of the present disclosure contribute to providing a communication device and a communication method for enhanced direct link communication.

[0007] According to a first embodiment of the present disclosure, there is provided a communication device configured to wirelessly communicate with an AP (access point) on a first channel, the communication device comprising: a circuit that, in operation, generates a channel use permission request frame including information indicating the communication device, another communication device, and a second channel different from the first channel; a transmitter that, in operation, transmits the generated channel use permission request frame to the AP to request permission from the AP to use the second channel for direct link communication with the other communication device; and a receiver that, in operation, receives a channel use permission response frame from the AP that grants use of the second channel; and the communication device is further configured to communicate with the other communication device on a direct link on the second channel after receiving the channel use permission response frame.

[0008] According to a second embodiment of the present disclosure, there is provided a communication device configured to wirelessly communicate with an AP (Access Point), the communication device comprising: a circuit that, in operation, generates a TDLS (Tunneled Direct Link Setup) RTS (Request To Send) frame including information indicating another communication device; a transmitter that, in operation, transmits the generated TDLS RTS frame to the AP to request a TXOP (Transmit Opportunity) for TDLS transmission with the other communication device; and a receiver that, in operation, receives a TDLS CTS (Clear To Send) frame from the AP, wherein the transmitter is further configured, after receiving the TDLS CTS frame, to transmit one or more data frames to the other communication device over a TDLS direct link in the requested TXOP.

[0009] According to a third embodiment of the present disclosure, there is provided an AP (Access Point) configured to wirelessly communicate with a communication device on a first channel, the AP comprising: a receiver configured, in operation, to receive from the communication device a channel use permission request frame requesting the use of a second channel different from the first channel for direct link communication with another communication device; a circuit configured, in operation, after receiving the channel use permission request frame, to determine from a frequency coordination database whether the second channel may be used by the communication device and the other communication device, and further to generate a channel use permission response frame including information indicating the determination; and a transmitter configured, in operation, to transmit the channel use permission response frame to the communication device configured to communicate with the other communication device on a direct link on the second channel based on the determination.

[0010] According to a fourth embodiment of the present disclosure, there is provided an AP (Access Point) configured to wirelessly communicate with a communication device, the AP including: a receiver that, in operation, receives from the communication device a TDLS Request To Send (RTS) frame that includes information indicating another communication device and requests the AP for a Transmission Opportunity (TXOP) for a TDLS (Tunneled Direct Link Setup) transmission with the other communication device; a circuit that, in operation, generates a TDLS Clear To Send (CTS) frame; and a transmitter that, in operation, transmits the TDLS CTS frame to the communication device, wherein the communication device is configured to, after receiving the TDLS CTS frame, transmit one or more data frames in the requested TXOP to the other communication device over a TDLS direct link.

[0011] According to a fifth embodiment of the present disclosure, there is provided a communication method, which includes generating a channel use permission request frame including information indicating a communication device, another communication device, and a second channel different from a first channel, transmitting the generated channel use permission request frame to an AP to request permission from the AP to use the second channel for direct link communication with the other communication device, receiving a channel use permission response frame from the AP that permits use of the second channel, and communicating with the other communication device on the second channel via a direct link on the second channel after receiving the channel use permission response frame.

[0012] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0013] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0014] Embodiments of the present disclosure will be better understood and readily appreciated by those skilled in the art from the following written description, given by way of example only, taken in conjunction with the drawings in which: [Figure 1A] 1 is a schematic diagram for setting up direct link communication between two stations (STAs). [Figure 1B] 1 is a schematic diagram of direct link communication between two terminals (STAs) in an infrastructure network. [Figure 1C] 1 is a schematic diagram of direct link communication between two terminals (STAs) in a Wi-Fi Direct (peer-to-peer) network. [Figure 2] 10 is a message flow showing TDLS setting in an off-channel in the 6 GHz band according to the first embodiment. [Figure 3] 4 is a message flow illustrating TDLS channel switching to an off-channel in the 6 GHz band according to the first embodiment. [Figure 4A] 1 illustrates the format of a TDLS Setup Request frame used to request a TDLS direct link setup, according to various embodiments. [Figure 4B] FIG. 2 is a diagram illustrating the format of a TDLS Channel Use Permission Request frame used to request permission to use a channel for direct link communication according to the first embodiment. [Figure 4C]FIG. 2 is a diagram illustrating the format of a TDLS Channel Use Permission Response frame used to respond to a TDLS Channel Use Permission Request frame according to the first embodiment. [Figure 5] 6 is a message flow illustrating the configuration of a traffic stream for a TDLS direct link in the 6 GHz band according to the first embodiment. [Figure 6] 5 is a flowchart showing the configuration of multi-band traffic streams for a TDLS direct link in the 6 GHz band according to the first embodiment. [Figure 7] FIG. 2 is a diagram showing the format of an EDCA (Enhanced Distributed Channel Access) parameter set element according to the first embodiment. [Figure 8] 2A to 2C are diagrams illustrating formats of an ADDTS request (Add Traffic Stream Request) frame and an ADDTS response (ADDTS Response) frame according to the first embodiment. [Figure 9] FIG. 3 is a diagram showing the format of a Cease Operation element used for a Cease Operation instruction according to the first embodiment. [Figure 10] 10 is a flowchart illustrating direct link communication between two STAs in a TXOP (Transmission Opportunity) according to a second embodiment. [Figure 11A] FIG. 10 is a diagram illustrating a format of a TDLS trigger frame used to start direct link communication according to a second embodiment. [Figure 11B] FIG. 10 is a diagram illustrating an alternative format of a TDLS Trigger frame used to initiate direct link communication according to the second embodiment. [Figure 12] FIG. 10 is a diagram illustrating a format of a TDLS Action frame used to report a TDLS buffer status according to a second embodiment. [Figure 13] 10A and 10B are diagrams illustrating formats of a TDLS RTS (Request to Send) frame and a TDLS CTS (Clear to Send) frame according to a third embodiment. [Figure 14] 10 is a message flow illustrating direct link communication between two STAs in a TXOP according to a third embodiment. [Figure 15] 1 illustrates a schematic example of a communication device, according to various embodiments, which may be implemented as an AP or a STA and may be configured for enhanced direct link communication according to various embodiments of the present disclosure. [Figure 16] FIG. 1 illustrates a flow diagram of a communication method, according to various embodiments. [Figure 17] 1 illustrates a configuration of a communication device, eg, a communication unit or terminal (STA), according to various embodiments. [Figure 18] 1 illustrates a configuration of a communication device, such as an AP, according to various embodiments. [Figure 19] 1 illustrates a reference structure for a multi-band communication device, e.g., a STA, that can participate in direct link communication, according to various embodiments.

[0015] Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some elements in the figures, block diagrams, or flowcharts may be exaggerated relative to other elements to facilitate an accurate understanding of the present embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiments of the present disclosure will now be described, by way of example only, with reference to the drawings in which like reference numbers and letters indicate like or equivalent elements.

[0017] In the following paragraphs, some example embodiments are described with reference to an access point (AP) and a station (STA) for enhanced direct link communication.

[0018] In IEEE 802.11 (Wi-Fi) technology, a terminal, also called a STA, is a communications device that supports the use of the 802.11 protocol. Based on the definition in IEEE 802.11-2016, a STA is any device that includes an IEEE 802.11-compliant medium access control (MAC) and physical layer (PHY) interface to a wireless medium (WM).

[0019] For example, a STA may be a laptop, a desktop personal computer (PC), a personal digital assistant (PDA), an access point in a wireless local area network (WLAN) environment, or a Wi-Fi phone. A STA may be fixed or mobile. In a WLAN environment, the terms "STA," "wireless client," "user," "user device," and "node" are often used interchangeably.

[0020] Similarly, an AP, also called a WAP (wireless access point) in IEEE 802.11 (Wi-Fi) technology, is a communications device that allows STAs in a WLAN to connect to a wired network. APs typically connect to a router (through the wired network) as standalone devices, but may also be integrated into or subsumed by a router.

[0021] As mentioned above, a STA in a WLAN can occasionally operate as an AP, and vice versa. This is because a communication device in IEEE 802.11 (Wi-Fi) technology may include both STA hardware components and AP hardware components. In this way, the communication device can switch between STA mode and AP mode based on actual WLAN conditions and / or requirements.

[0022] Direct link communication (also known as peer-to-peer or device-to-device communication) offers many advantages. In traditional wireless networks, such as IEEE 802.11 WLANs, all communication must go through an access point (AP), even if the two devices involved are part of the same wireless network (called a Basic Service Set (BSS) in 802.11). To make such device-to-device communication more efficient, the IEEE 802.11z amendment introduced tunneled direct link setup (TDLS). TDLS is characterized by the use of setup frames encapsulated in data frames that can be transparently transmitted through the AP, hence the term "tunneling." For example, all management frames related to TDLS configuration, such as the TDLS setup request frame and the TDLS setup response frame, are encapsulated within data frames, making TDLS configuration completely transparent to the AP. In fact, the AP may not even need to be TDLS-enabled. A communication link between two devices using TDLS is known as a TDLS direct link, or simply a TDLS link. Because packets between two devices are exchanged directly over the TDLS link and do not go through the AP, TDLS can reduce packet transmission by half. Therefore, a TDLS link can increase the efficiency of a wireless network, especially when two devices are located relatively closer to each other than the AP. A TDLS link can also utilize higher data rates due to the shorter distance between devices compared to a wireless link with an AP.

[0023] FIG. 1A is a schematic diagram 100 for setting up direct peer-to-peer communication between two non-AP STAs. To set up direct link communication between the STAs 104 and 106, the STA 104 can transmit a TDLS setup request frame to the STA 106 via the AP 102 (as shown by transmission paths 1a and 1b). Then, in response to receiving the TDLS request frame, the STA 106 can transmit a TDLS setup response frame to the STA 104 via the AP 102 (as shown by transmission paths 2a and 2b). The TDLS setup request frame and the TDLS setup response frame are management frames for setting up a TDLS. The TDLS setup is transparent to the AP 102 because the TDLS setup request frame and the TDLS setup response frame are data-encapsulated and transmitted directly between the APs. Once the TDLS is set up, the two STAs 104 and 106 can communicate directly with each other via a “direct link.” The direct link may be switched to a channel different from the operating channel of the BSS (base channel) and may be on a different band; such a direct link channel is called "off-channel."

[0024] Currently, the AP does not control TDLS configuration / usage. However, in the 6 GHz band, client devices are only allowed to operate in the 6 GHz band while under the control of the AP. When operating in the 5 GHz DFS (Dynamic Frequency Selection) band, the TDLS initiator STA acts as a DFS owner (DO), but in the 6 GHz band, the TDLS STA may not have such support.

[0025] Therefore, this invention describes an extended direct link communication procedure that allows an AP to have more control over direct link communication in a specific band / channel. Without such an extended function, direct links such as TDLS may not be usable in the 6 GHz band.

[0026] When operating in some subbands of the 6 GHz band (e.g., U-NII-5 and U-NII-7), an AP may be required to consult an Automatic Frequency Control (AFC) database to determine allowable operating frequencies and transmission parameters. Such an AP may be referred to as an ADD (AFC Database Dependent)-enabled STA, and non-AP STAs associated with such an AP may be referred to as ADD-dependent STAs. Non-AP STAs may be able to communicate on channels on these subbands only if they are "enabled" by an enabling STA, and such non-AP STAs may be said to be "under the control" of the AP. An AP may announce its presence on a channel requiring activation by periodically transmitting an activation signal on the channel, for example, by including such an activation signal in a beacon frame.

[0027] When two ADD-dependent STAs negotiate a TDLS direct link over the base channel, they can use the same transmission parameters for transmission on the TDLS direct link as those used for the AP link.

[0028] Figure 1B is a schematic diagram 110 of TDLS direct link communication between two stations (STAs) in a channel infrastructure network. Another advantage of TDLS is that because TDLS is transparent to the AP, if both devices support more advanced capabilities than the AP, the TDLS link can operate at higher capabilities that may not be supported by the AP. For example, an AP 112 may only support 802.11ac, but two TDLS devices may both support the latest 802.11ax revision. In this case, the devices can communicate at higher 802.11ax data rates over the direct link. Furthermore, even if two devices are multi-band devices and connect to an AP in the 5 GHz band (base channel), if both devices support the 6 GHz band, the two devices may choose to switch their TDLS link to a wider channel in the 6 GHz band (off-channel TDLS link) even though the AP itself does not operate in the 6 GHz band.

[0029] As described above, the AP 112 may consult the AFC database 118 to determine allowable operating frequencies and transmission parameters. If the TDLS link between the ADD-dependent STAs 114, 116 is on the operating channel of the BSS, i.e., if the direct link is on the base channel, the STAs 114, 116 may use the same transmission parameters for transmissions on the TDLS link as were used for the AP link. While FIG. 1B shows a direct link between the AP and the AFC database, in practice, the AP may rely on the AFC system to check channel availability in the AFC database. Alternatively, there may be no direct interaction between the AP and the AFC database, and all decisions regarding channel availability (frequency usage) in a particular geolocation may be made by the AFC system.

[0030] However, if two non-AP STAs attempt to establish or switch a TDLS direct link to a channel in the 6 GHz band that is not the base channel, the following rules shall apply: The associated AP is an ADD-enabled STA. The TDLS initiator STA requests permission to use the channel for the direct link from the AP by sending a TDLS Channel Use Permission Request frame to the AP. The AP responds by sending a TDLS Channel Use Permission Response frame. The direct link may be configured / switched to a channel in the 6 GHz band other than the base channel only after receiving a TDLS Channel Use Permission Response frame with a status of SUCCESS from the AP.

[0031] FIG. 1C is a schematic diagram 120 of direct link communication between two stations (STAs) in a Wi-Fi Direct (peer-to-peer) network. TDLS links can also operate within temporary wireless networks, such as the Wi-Fi Alliance Wi-Fi Direct network. A Wi-Fi Direct network is a device-to-device network in which one device acts as a "group owner" (GO) and does not require a traditional AP. For example, in FIG. 1C, a smartphone 122 acts as the GO, and a Wi-Fi-enabled printer 124 and a Wi-Fi-enabled digital camera 126 can join the Wi-Fi Direct network by forming a Wi-Fi Direct connection with the GO. In this case, the GO acts as an AP and may establish a TDLS link between the digital camera 126 and the printer 124 so that the digital camera 126 can send photos directly to the printer 124 for printing. Again, if both the digital camera 126 and the printer 124 are multi-band devices and both support the 6 GHz band, the two devices may choose to switch their TDLS link to a wider channel in the 6 GHz band (an off-channel TDLS link). In this example, as long as the smartphone 122 has access to the Internet and can access the AFC database 128 (via the AFC system), it can act as an ADD-enabled STA and issue permissions for two TDLS devices to transmit over the TDLS direct link on channels within the U-NII-5 and U-NII-7 sub-bands of the 6 GHz band.

[0032] FIG. 2 is a message flow illustrating TDLS configuration off-channel in the 6 GHz band according to a first embodiment. The AP 202 may be an ADD-enabled STA. Non-AP STAs 204 and 206 associate with the AP 202 on channels in the 6 GHz band. For various reasons, the non-AP STAs 204 and 206 may choose to communicate over a direct link on a channel different from the operating channel of the BSS. Regulatory requirements in the 6 GHz band may require checking channel availability from the AFC system before any transmission on the channel. The non-AP STA 204, which is a TDLS initiator STA, can request permission from the AP 202 to use a different channel in the 6 GHz band for direct link communication with the non-AP STA 206 by sending a TDLS Channel Use Permission Request frame 208 to the AP 202. The channel may be, for example, a channel in the U-NII-5 or U-NII-7 sub-band of the 6 GHz band that is different from the base channel of the 6 GHz band used for communication between the AP 202 and the STAs 204, 206.

[0033] After receiving the TDLS Channel Use Permission Request frame 208 from the STA 204, the AP 202 checks the AFC database (e.g., via the AFC system) for the availability of the requested channel. If successful, the AP 202 may send a TDLS Channel Use Permission Response frame 210 with a status of SUCCESS to the STA 204 to indicate that the requested channel is available for direct link communication. The STA 204 can then initiate setup of a direct link with the STA 206 on the requested channel by sending a TDLS Setup Request frame 212 to the STA 206 via the AP 202. The STA 206 may respond by sending a TDLS Setup Response frame 214 to the STA 204 via the AP 202. The STA 204 then sends a TDLS Setup Confirm frame 216 to the STA 206 via the AP 202, and a TDLS direct link is established on the requested channel in the 6 GHz band. In the event of a failure where the requested channel is unavailable after checking the AFC database, the AP 202 may send a TDLS Channel Use Permission Response frame 210 to the STA 204, including a failure status (e.g., TDLS_CHANNEL_USE_DENIED), to indicate that use of the requested channel for direct link communication has been denied.

[0034] 3 is a message flow illustrating a TDLS direct link channel switch to an off-channel in the 6 GHz band according to the first embodiment. In this example, non-AP STAs 304 and 306 are associated with the AP 302 on a channel in the 5 GHz band, and a TDLS direct link is already established on the base channel. However, the STA 304 is attempting to switch the direct link to an off-channel in the 6 GHz band. Therefore, the STA 304, which is the TDLS initiator STA, can request permission from the AP 302 to use another channel in the 6 GHz band for direct link communication with the STA 306 by transmitting a TDLS Channel Use Permission Request frame 308 to the AP 302. The channel may be, for example, a channel in the 6 GHz band different from the base channel in the 5 GHz band used for communication between the AP 302 and the STAs 304 and 306.

[0035] After receiving the TDLS Channel Use Permission Request frame 308 from the STA 304, the AP 302 checks the AFC database for the availability of the requested channel. If successful, the AP 302 may send a TDLS Channel Use Permission Response frame 310 with a status of SUCCESS to the STA 304 to indicate that the requested channel is available for direct link communication. The STA 304 can then initiate a switch of the direct link with the STA 306 to the requested channel in the 6 GHz band by sending a TDLS Channel Switch Request frame 312 to the STA 306. The STA 306 responds by sending a TDLS Channel Switch Response frame to the STA 304 with a status of SUCCESS, and the TDLS direct link is switched to the requested channel in the 6 GHz band. In the case of a failure where the requested channel is unavailable upon checking the AFC database, the AP 302 may send a TDLS Channel Use Permission Response frame 310 with a status of failure to the AP 304 to indicate that switching the direct link to the requested channel has been denied.

[0036] It will be appreciated that if the STA 204, 304 (TDLS initiator STA) has the capability to directly check the AFC database regarding the use of off-channels in the 6 GHz band for a direct link (e.g., via a cellular Internet link), it can directly set up / switch the direct link to off-channel without needing to seek permission from the AP 202, 302.

[0037] 4A is a diagram illustrating the format of a TDLS Setup Request frame 400 used to request a TDLS direct link setup, according to various embodiments. The TDLS Setup Request frame 400 may be used in the form of the TDLS Setup Request frame 212 transmitted by the STA 204 to the STA 206 via the AP 202, as shown in FIG. 2. The TDLS Setup Request frame 400 may include (or consist of) a Frame Control field, a Duration field, one or more Address fields, a Sequence Control field, an HT Control field, a Category field, a TDLS Action field, a Dialog Token field, an optional Target Channel field, an optional Wide Bandwidth Channel Switch element field, and a frame check sequence (FCS) field. The Target Channel field may include (or consist of) an Operating Class field and a Channel Number field. The Channel Number field may indicate the channel to be used for the requested direct link communication. The Target Channel field and a Wide Bandwidth Channel Switch element field may be present in the TDLS Setup Request frame 400 to request a TDLS setup on a channel different from the base channel.Additionally, a Wide Bandwidth Channel Switch element field may be present if the TDLS Setup Request frame 400 is used to request a channel wider than 20 MHz. Although not shown, if a TDLS link is set up on a different frequency band and if the STA's MAC address on that frequency band is different from the band in which the base channel resides, a MAC address on the other band may also be included in the TDLS Setup Request frame. If the peer STA accepts the TDLS setup request, it may include its own MAC address on the other band in the TDLS Setup Request Response frame. If necessary, setting up a TDLS link on a different channel may also trigger the establishment of a TDLS Peer Key (TPK) security association on the other channel.

[0038] 4B is a diagram illustrating the format of a TDLS Channel Use Permission Request frame 410 used to request permission to use a channel for direct link communication according to the first embodiment. The TDLS Channel Use Permission Request frame 410 may be used in the form of the TDLS Channel Use Permission Request frame 208, 308 transmitted by the STA 204, 304 to the AP 202, 302 as shown in FIGS. 2 and 3. The TDLS Channel Use Permission Request frame 410 may include (or consist of) a Frame Control field, a Duration field, one or more Address fields, a Sequence Control field, an HT Control field, a Category field, a TDLS Action field, a Dialog Token field, a Link Identifier element field, optionally a Device Information field, a Target Channel field, optionally a Wide Bandwidth Channel Switch element field, and an FCS field. The Device Information field may include (or consist of) a First Device ID field, a First Device Location field, a Second Device ID field, and a Second Device Location field.The device ID, which may be, for example, the FCC ID of the device, may be used by the AFC system to verify whether the device may be used on that channel. Similarly, the Device Location field may provide information about the device's geographic location, such as latitude, longitude, and optionally, antenna height. The Target Channel field may include (or consist of) an Operating Class field and a Channel Number field (not shown) that identifies the channel requested for direct link communication. A Wide Bandwidth Channel Switch element field may also be present when requesting a channel wider than 20 MHz. The device location information may be used by the AFC system to calculate whether transmissions from any TDLS device on the requested channel may cause interference to licensed users operating in the vicinity. The AFC system may consider many factors in making such a determination, including the licensed users' receiving antennas and information about the terrain (rural, urban, semi-rural, etc.). If the AFC system determines that direct link transmissions on the requested channel will not cause any interference to nearby licensed users, the use of the requested channel for direct link communication may be permitted. Alternatively, the AFC system can simplify the interference calculation by using information about the AP (location, antenna height, etc.) to perform the interference calculation under the assumption that transmissions by the AP on the requested channel do not cause interference to licensed users, and that transmissions by any client devices (i.e., TDLS STAs) do not cause interference to licensed users.

[0039] 4C is a diagram showing the format of a TDLS Channel Use Permission Response frame 420 according to the first embodiment, which is used to respond to a TDLS Channel Use Permission Request frame 410. The TDLS Channel Use Permission Response frame 420 may be used in the form of the TDLS Channel Use Permission Response frame 210, 310 transmitted by the AP 202, 302 to the STA 204, 304, as shown in FIGS. The TDLS Channel Use Permission Response frame 420 may include (or consist of) a Frame Control field, a Duration field, one or more Address fields, a Sequence Control field, an HT Control field, a Category field, a TDLS Action field, a Dialog Token field, a Status field, a Maximum Power Level field, a Validity Period field, optionally an Alternate Channel field, optionally a Wide Bandwidth Channel Switch element field, and an FCS field.

[0040] The Status field may indicate "SUCCESS" if the channel requested in the TDLS Channel Use Permission Request frame is usable for direct link communication, or may indicate "TDLS_CHANNEL_USE_DENIED" if the channel requested in the TDLS Channel Use Permission Request frame (e.g., the channel indicated in the Channel Number field of the TDLS Channel Use Permission Request frame) is not usable for direct link communication. If the status is not SUCCESS, the AP may include an Alternate Channel field and a Wide Bandwidth Channel Switch element in the TDLS Channel Use Permission Response frame to recommend another channel for direct link communication. The TDLS Channel Use Permission Response frame 420 may also include applicable transmission parameters (e.g., a maximum transmit power level), a validity period for using the channel, etc.

[0041] The Maximum Power Level field may indicate the maximum power, in units of 0.5 dBm, allowed to be transmitted on the channel indicated in the Channel Number field. The Validity Period field may indicate the period for which the Channel Use Permission is valid. Upon expiration of the validity period, the STA is to again seek permission from its associated AP, for example, by sending another TDLS Channel Use Permission Request frame to the associated AP. The TDLS Channel Use Permission Request / Response frames may be understood to be transmitted directly to and from the AP without data encapsulation.

[0042] Furthermore, a non-AP STA may be required to set up a traffic stream (TS) for the TDLS direct link before transmitting a data frame over the TDLS direct link in the 6 GHz band. FIG. 5 is a message flow diagram illustrating setting up a TS for the TDLS direct link on a channel in the 6 GHz band according to the first embodiment. The STA 504 can send an ADDTS request frame 508 to the AP 502. The ADDTS request frame 508 may include information identifying the TDLS direct link. For example, the STA 504 may include a link identifier element in the ADDTS request frame 508 to notify the TDLS of the TS and to identify the addresses of the initiator STA (e.g., STA 504) and the recipient STA (e.g., STA 506). If the AP 502 authorizes the TS, the AP 502 creates a TS for the TDLS direct link. By having information about both STAs involved in the TDLS link, the AP can make a more appropriate decision. For example, if an AP knows that two STAs are physically close to each other, it can provide more transmission opportunities for the direct link, or it can reject traffic setup requests between STAs that are far from each other to prevent interference to other STAs.

[0043] The AP 502 may also send an ADDTS response frame 510 to the STA 504, and may include a Link Identifier element in the ADDTS response frame 510 to indicate the TDLS link. If the TS is bidirectional, the STA 504 may send a TDLS Setup Confirm frame 512 to the STA 506 to notify the STA 506 that the TS setup was successful. The TDLS Setup Confirm frame 512 may notify the STA 506 of the TSPEC (Traffic Specification) and TID (Traffic ID) of the TS. Alternatively, the STA 506 may repeat the TS setup in the reverse direction. In this example, it is assumed that a TDLS direct link has already been established between the STA 504 and the STA 506. If not, the two STAs 504 and 506 can perform TDLS setup immediately after the traffic stream for the TDLS link has been successfully set up. After the TS is successfully configured, one or more data frames 514 belonging to the TID may be transmitted on the TDLS direct link. If a TS is required for the TDLS direct link, failure to configure the TDLS TS disallows transmission of data frames on the TDLS direct link. Configuring a TS by the AP 502 advantageously allows the AP 502 to establish control over communication traffic between non-AP STAs 504, 506.

[0044] When the operating channel of the BSS is in the 5 GHz or 2.4 GHz band and the TDLS direct link is switched to a channel in the 6 GHz band (off-channel), the TDLS TS may be set in the 6 GHz band, but the actual TDLS TS setting is performed on the operating channel of the BSS. FIG. 6 is a message flow showing the setting of a traffic stream for a TDLS direct link in the 6 GHz band off-channel according to the first embodiment. The STA 604 can transmit an ADDTS request frame 608 to the AP 602 on the BSS operating channel. The ADDTS request frame 608 may include information identifying the TDLS direct link. For example, the STA 604 may include a link identifier element in the ADDTS request frame 608 to notify the TDLS of the TS and to identify the addresses of the initiator STA (e.g., STA 604) and the recipient STA (e.g., STA 606). The ADDTS request frame 608 may also include a multi-band element indicating the 6 GHz band and the channel to be switched in the 6 GHz band. If the AP 602 authorizes the TS, the AP 602 creates a TS for the TDLS direct link in the 6 GHz band.

[0045] The AP 602 may also transmit an ADDTS response frame 610 to the STA 604 on the BSS operating channel, and the ADDTS response frame 610 may include a Link Identifier element indicating the TDLS link. The ADDTS response frame 610 may also include a multi-band element indicating the channel to be switched to in the 6 GHz band. The STA 604 may then transmit a TDLS Setup Confirm frame 612 to the STA 606 via the AP 602 (i.e., encapsulated in a data frame) to notify the STA 606 that the TS setup has been successful. The TDLS Setup Confirm frame 612 may also notify the STA 606 of the TSPEC (Traffic Specification) and TID (Traffic ID) of the TS. In this example, it is assumed that a TDLS direct link has already been established between the STA 504 and the STA 506 on the 6 GHz channel. After the TS is successfully configured, one or more data frames 614 belonging to the TID may be transmitted on the TDLS direct link, and the STAs 604 and 606 may then be in PS (power save) mode with respect to the AP 602. The TS configuration by the AP 602 advantageously allows the AP 602 to establish control over communication traffic between the non-AP STAs 604, 606.

[0046] The AP can notify that a TDLS TS configuration is required for an AC in the 6 GHz band by setting a "TDLS ACM" bit in a parameter record field of an access category (AC) in an EDCA parameter set (Enhanced Distributed Channel Access Parameter Set) element transmitted in a beacon / probe response frame in the 6 GHz band. FIG. 7 is a diagram showing the format of an EDCA parameter set element 700 according to the first embodiment. The EDCA parameter set element 700 may include (or be composed of) an element ID field, a length field, a QoS information field, an update EDCA information field, an AC_BE parameter record field, an AC_BK parameter record field, an AC_VI parameter record field, and an AC_VO parameter record field. The AC_BK Parameter Record field may include (or consist of) an ACI / AIFSN field, an ECWmin / ECWmax field, and a TXOP Limit field. The ACI / AIFSN field may include (or consist of) an AIFSN subfield, an ACM subfield, an ACI subfield, and a TDLS ACM subfield. If the TDLS ACM subfield bit is set, data transmission on the TDLS direct link in the 6 GHz band is allowed only after the STA establishes a TDLS TS for that AC with the AP (regardless of the setting of the ACM bit for that AC).On the other hand, if the TDLS ACM subfield bit is not set, data transmission over the TDLS direct link in the 6 GHz band is permitted for that AC without requiring TS configuration. The TDLS ACM subfield allows the AP to have more control over direct link communication with non-AP STAs, which is advantageous.

[0047] 8 is a diagram showing the formats of an ADDTS request frame 800 and an ADDTS response frame 802 according to the first embodiment. The ADDTS request frame 800 may be used in the form of the ADDTS request frames 508, 608 transmitted by the STAs 504, 604 to the APs 502, 602 as shown in FIGS. The ADDTS Request frame 800 may include (or consist of) a Frame Control field, a Duration field, an Address 1 (RA) field, an Address 2 (TA) field, an Address 3 (BSSID) field, a Sequence Control field, an HT Control field, a Category field, a QoS Action field, a Dialog Token field, a TSPEC element field, a Link Identifier element field, and an FCS field. As shown in the examples of Figures 5 and 6, the ADDTS Request frame is transmitted by an initiator STA to an AP to request that the AP set up a TS for a direct link.

[0048] The ADDTS Response frame 802 may be used in the form of an ADDTS Response frame 510, 610 transmitted by the AP 502, 602 to the STA 504, 604, as shown in Figures 5 and 6. The ADDTS Response frame 802 may include (or consist of) a Frame Control field, a Duration field, an Address 1 (RA) field, an Address 2 (TA) field, an Address 3 (BSSID) field, a Sequence Control field, an HT Control field, a Category field, a QoS Action field, a Dialog Token field, a Status Code field, a TS Delay field, a TSPEC element field, a Link Identifier element field, and an FCS field. 5 and 6, an ADDTS Response frame is sent by the AP to the initiator STA to confirm that the TS has been set up. The TDLS direct link may be identified in the ADDTS Request / Response frame by a Link Identifier element field, which may include (or consist of) an Element ID field, a Length field, a BSSID field, a TDLS Initiator STA Address field, and a TDLS Responder STA Address field.

[0049] An AP may instruct associated non-AP STAs to cease operation on the TDLS direct link in the 6 GHz band by including a Cease Operation element in a broadcast / unicast frame addressed to the STA. For example, this Cease Operation instruction may be sent by the AP upon detection of a primary user of the spectrum (e.g., due to a change in the AFC database), upon instruction from the AFC system, or other similar circumstances. Such a requirement to cease operation may include immediately ceasing all ongoing transmissions and may be mandated by a regulatory body to protect licensed users of the spectrum from harmful interference. Figure 9 illustrates the format of a Cease Operation element 900 used in a Cease Operation instruction according to the first embodiment. The Cease Operation element 900 may include (or consist of) an Element ID field, a Length field, an Extended Element ID field, a BSSID field, a Band ID field, an Operating Class field, an Operating Channel field, and a Reason Code field. The Band ID field (if present), the Operating Class field, and the Operating Channel field together identify the frequency band and channel to which the Cease Operation applies. The Reason Code field may indicate the reason why the STA requests to cease operation on the direct link. For example, a value of '0' indicates that primary or licensed use was detected, a value of '1' indicates that use of the channel was not permitted by the AFC system in the AFC database, and other values ​​from 2 to 255 may be reserved for other reasons. For example, other reasons may include a licensed user of the channel reporting interference to the AFC system.

[0050] When a STA receives a cease operation instruction from an AP along with the cease operation element 900, the STA stops all operations on the TDLS direct link in the indicated channel. This may include, for example, stopping transmission on the direct link, disconnecting the direct link, or deleting the TDLS TS associated with the direct link. The AP can advantageously control TDLS direct link setup / transmission in the 6 GHz band by using the cease operation instruction.

[0051] In a second embodiment, the AP may only allow scheduled transmission of data frames, even over a TDLS direct link; therefore, TDLS data frame transmission may require the receipt of a TDLS Trigger frame from the AP. While the AP can exercise some control over transmissions over the TDLS link by requiring TDLS STAs to configure TS settings for the TDLS link, some regulatory domains may require the AP to exercise much stricter control over which STAs can transmit on the wireless medium and when. In such a scenario, the AP may disable all contention-based transmissions (e.g., EDCA) and allow only AP-scheduled transmissions. Upon receiving a TDLS Trigger frame, the TDLS initiator STA can transmit one or more data frames to the TDLS receiver STA over the TDLS direct link within the TXOP period. Figure 10 is a message flow diagram illustrating direct link communication between two STAs in a TXOP according to the second embodiment. The AP 1002 can generate and send a TDLS Trigger frame 1008 to the STA 1004. The STA 1004 receives a TDLS Trigger frame 1008 and, after a Short Interframe Spacing (SIFS) 1010, transmits one or more TDLS Data frames 1012 to the STA 1006 within a TXOP 1016. The STA 1006 can acknowledge each TDLS Data frame 1012 received from the AP 1004 by transmitting an acknowledgement frame 1014 (ACK frame or BlockAck frame) to the STA 1004.In various embodiments, the TDLS Trigger frame 1008 may include information indicating the MAC address, authorized access category (AC), and maximum transmit power level of the STA 1004, and one or more data frames are transmitted to the MAC address based on a TID specified in the authorized AC or a higher AC, and the one or more data frames are transmitted at a transmit power less than the maximum transmit power level.

[0052] EDCA-based transmission of data frames is not permitted on the TDLS direct link. Furthermore, such triggered transmission according to the second embodiment is only possible when the TDLS direct link is in the base channel. Therefore, a TDLS channel switch to an off-channel in the 6 GHz band may not be permitted. The AP 1002 may use parameters of the TDLS TS, as well as a TDLS Buffer Status Report, to schedule the transmission of a TDLS Trigger frame 1008.

[0053] FIG. 11A is a diagram showing the format of a TDLS trigger frame 1100 used to initiate direct link communication according to the second embodiment. The TDLS trigger frame 1100 may be available in the form of the TDLS trigger frame 1008, as shown in FIG. 10. The TDLS trigger frame 1100 may include (or consist of) a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, a User Info field, a Padding field, and an FCS field. The RA field may be set to, for example, the MAC address of the TDLS initiator STA. In the example shown in FIG. 10, this is the MAC address of the STA 1004 transmitting the data frame 1012. The Common Info field may include a Trigger Type field, which may contain a value of "8" to indicate that the frame is a TDLS Trigger frame. All other fields in the Common Info field, except for the Trigger Type field and the CS Required field, may be reserved. There is no Trigger Dependent Common Info field. The User Info field may include an AID12 field and a Trigger Dependent User Info field. There may be only one User Info field. The AID12 field may be set to the AID of the TDLS initiator STA. In the example shown in Figure 10, this is the AID of STA 1004.The Trigger Dependent User Info field may further include (or consist of) a Destination MAC address field, an Allowed AC field, and a Maximum Power Level field. The Destination MAC address field may, for example, indicate the MAC address of the TDLS receiving STA. In the example shown in FIG. 10, this is the MAC address of the STA 1006 that is intended to receive the data frame 1012. All other fields in the Trigger Dependent User Info field may be reserved. A TDLS initiator STA that receives the TDLS trigger frame 1100 may be allowed to transmit data frames addressed to the TDLS receiving STA from either the AC indicated in the Allowed AC field or from other, higher priority ACs.

[0054] 11B is a diagram showing an alternative format of a TDLS trigger frame used to initiate direct link communication according to the second embodiment. Alternatively, the format of the TDLS trigger frame can be simplified to a format shown in a TDLS trigger frame 1102. The TDLS trigger frame 1102 may include (or consist of) a Frame Control field, a Duration field, an RA field, a TA field, a Trigger Type field, a CS Required field, an Allowed AC field, a Maximum Power Level field, a Destination MAC address field, and an FCS field. Therefore, the TDLS trigger frame 1008 in FIG. 10 may be in the format of the simplified TDLS trigger frame 1102.

[0055] Also, a new TDLS Action frame (TDLS Buffer Status Report) may be defined so that a STA can report its own TDLS buffer status to an AP. FIG. 12 is a diagram showing the format of a TDLS Action frame 1200 used to report the TDLS buffer status according to the second embodiment. The TDLS Buffer Status Report frame 1200 may include (or be composed of) a Frame Control field, a Duration field, an Address 1 field, an Address 2 field, an Address 3 field, a Sequence Control field, an HT Control field, a Category field, a TDLS Action field, a Link Identifier element field, one or more TDLS Buffer Status fields, and an FCS field. Each TDLS Buffer Status field may include (or be composed of) a TID field and a Queue Size field. The TDLS Action field may have a value of, for example, "11" to indicate that the action frame is a TDLS Buffer Status Report frame. The Link Identifier element field may contain information identifying the TDLS link. The TID may indicate the TID corresponding to the TDLS data frame. The Queue Size field may indicate the queue size of the TID corresponding to the data frame destined for the TDLS peer STA and may use the same encoding as the Queue Size subfield of the QoS Control field.If the TS is configured for a TDLS direct link, the TID field may correspond to the TSID.

[0056] The TDLS Buffer Status Report frame 1200 may be transmitted directly to and from the AP without data encapsulation. Advantageously, the AP can dynamically schedule TDLS Trigger frames 1100, 1102 using information provided in the TDLS Buffer Status Report frame 1200 to initiate TDLS transmissions in the 6 GHz band.

[0057] For example, the AP can indicate whether TS configuration is required for the 6 GHz TDLS direct link (bit #83) and / or whether a trigger frame is required for data frame transmission on the 6 GHz TDLS direct link (bit #84) in the Extended Capabilities field of the Beacon / Probe Response frame. Table 1 below shows the bit values ​​that the AP can use in the Extended Capabilities field of the Beacon / Probe Response frame to indicate the above requirements. This is advantageous as it gives the AP more control over the requirements for enabling TDLS direct link transmission in the 6 GHz band.

[0058] [Table 1]

[0059] According to the third embodiment, new RTS (Request to Send) and CTS (Clear to Send) frames can be defined for requesting and approving TDLS transmission. FIG. 13 shows formats of a TDLS RTS frame 1300 and a TDLS CTS frame 1302 according to the third embodiment. The TDLS RTS frame 1300 may be transmitted from a TDLS initiator STA to an associated AP to request a TXOP for TDLS transmission with another STA (e.g., a TDLS receiver STA). The TDLS RTS frame 1300 may include (or be composed of) a Frame Control field, a Duration field, an RA field, a TA field, a Destination MAC address field, and an FCS field. For example, the RA field may be set to the MAC address of the TDLS initiator STA, and the Destination MAC address field may be set to the MAC address of the TDLS receiver STA. The TDLS RTS frame differs from a normal RTS frame in that it includes a destination MAC address field.

[0060] The TDLS CTS frame 1302 may be transmitted by the AP to the TDLS initiator STA if the AP allows TDLS transmission. The TDLS CTS frame 1302 may include (or consist of) a Frame Control field, a Duration field, an RA field, a Destination MAC address field, and an FCS field. Similar to the Destination MAC address field of the TDLS RTS frame 1300, the Destination MAC address field of the TDLS CTS frame 1302 may be set to the MAC address of the TDLS receiving STA. The TDLS CTS frame differs from a normal CTS frame in that it includes a Destination MAC address field.

[0061] According to the third embodiment, transmission of a data frame on the TDLS direct link can be permitted only after an RTS / CTS exchange with the AP. Also, because transmission is only possible when the TDLS direct link is on the base channel, switching the TDLS channel to an off-channel in the 6 GHz band is not permitted. The RTS / CTS exchange advantageously allows the AP to dynamically permit / deny TDLS transmission in the 6 GHz band. One advantage of using this RTS and CTS procedure to initiate communication on the TDLS link is that it eliminates the AP's scheduling burden on the TDLS link, and while the TDLS initiator STA (STA1 1404 in this example) initiates the TDLS TXOP, the AP still has strict control over whether transmission on the TDLS direct link is permitted.

[0062] FIG. 14 is a message flow illustrating direct link communication between two STAs in a TXOP according to a third embodiment. STA 1404 can generate and send a TDLS RTS frame 1408 to AP 1402 to request a TXOP 1416 for TDLS transmission with STA 1406. The TDLS RTS frame 1408 can take the form of the TDLS RTS frame 1300 shown in FIG. 13 and can include information indicative of the STA 1406, such as the MAC address of the STA 1406. Then, upon receiving the TDLS RTS frame 1408, AP 1402 can generate and send a TDLS CTS frame 1410 to STA 1402 to authorize transmission. The TDLS CTS frame 1410 can take the form of the TDLS CTS frame 1302 shown in FIG. 13 and can include information indicative of the STA 1406, such as the MAC address of the STA 1406. Then, after receiving the TDLS CTS frame 1410, the STA 1404 can transmit one or more data frames 1412 to the STA 1406 within a request TXOP 1416. The STA 1406 can acknowledge each data frame by transmitting an acknowledgement frame 1414 to the STA 1404. In this example, it is assumed that both the STA 1404 and the STA 1406 are operating in active mode (i.e., not in power save mode).

[0063] 15 is a partially sectioned schematic diagram of a communications device 1500 according to various embodiments. The communications device 1500 can be implemented as an AP or a STA according to various embodiments.

[0064] As shown in Figure 15, communications device 1500 may include circuitry 1514, at least one wireless transmitter 1502, at least one wireless receiver 1504, and at least one antenna 1512 (for simplicity, only one antenna is shown in Figure 15 for illustrative purposes). Circuitry 1514 may include at least one controller 1506, which is used to perform the tasks it is designed to perform, including controlling communications with one or more other communications devices in a wireless network, with the assistance of software and hardware. Circuitry 1514 may further include at least one transmit signal generator 1508 and at least one receive signal processor 1510. The at least one control unit 1506 controls frames (for example, a TDLS Setup Request frame, a TDLS Setup Response frame, a TDLS Channel Use Permission Request frame, an ADDTS request frame, and a TDLS RTS frame, if the communication device 1500 is an STA, or a TDLS Channel Use Permission Response frame, an ADDTS response frame, an EDCA Parameter Set element frame, a cease operation instruction frame, a TDLS Trigger frame, a TDLS Buffer Status Report frame, and a TDLS RTS frame, if the communication device 1500 is an AP) transmitted to one or more other communication devices via the at least one wireless transmitter 1502.The at least one control unit 1506 may control at least one transmit signal generator 1508 to generate a TDLS CTS frame, and may also control frames received from one or more other communication devices via the at least one wireless receiver 1504 under the control of the at least one control unit 1506 (for example, if the communication device 1500 is an STA, a TDLS Channel Use Permission Response frame, an ADDTS response frame, an EDCA Parameter Set element frame, a cease operation instruction frame, a TDLS Trigger frame, a TDLS Buffer Status Report frame, and a TDLS CTS frame, and if the communication device 1500 is an AP, a TDLS Setup Request frame, a TDLS Setup Response frame, a TDLS Channel Use Permission Request frame, an ADDTS request frame, and a TDLS CTS frame).The at least one transmit signal generator 1508 and the at least one receive signal processor 1510 may control at least one receive signal processor 1510 to process the RTS frame. The at least one transmit signal generator 1508 and the at least one receive signal processor 1510 may be standalone modules of the communication device 1500, communicating with the at least one controller 1506 for the above-mentioned functions, as shown in FIG. 15 . Alternatively, the at least one transmit signal generator 1508 and the at least one receive signal processor 1510 may be included in the at least one controller 1506. Those skilled in the art will appreciate that the arrangement of these functional modules is flexible and may vary according to actual needs and / or requirements. Data processing, storage, and other related control devices may be provided on an appropriate circuit board and / or chipset. In various embodiments, during operation, the at least one wireless transmitter 1502, the at least one wireless receiver 1504, and the at least one antenna 1512 may be controlled by the at least one controller 1506.

[0065] In operation, the communication device 1500 provides functionality necessary for enhanced direct link communication. For example, the communication device 1500 may be a station (STA) configured to wirelessly communicate with an AP over a first channel, and the circuit 1514 (e.g., at least one transmission signal generator 1508 of the circuit 1514) may, in operation, generate a channel grant request frame including information identifying the communication device 1500, another communication device, and a second channel different from the first channel. The wireless transmitter 1502 may, in operation, transmit the generated channel grant request frame to the AP to request permission from the AP to use the second channel for direct link communication with the other communication device. The wireless receiver 1504 may, in operation, receive a channel grant response frame from the AP granting use of the second channel, and the communication device 1500 is further configured to communicate with the other communication device over a direct link on the second channel after receiving the channel grant response frame.

[0066] The direct link may be a TDLS direct link. The channel use grant response frame may include information indicating a maximum transmission power level and a valid period for using the second channel, and communication between the communication device and the other communication device on the direct link is stopped upon expiration of the valid period.

[0067] Additionally, the wireless receiver 1504 may be further configured to receive a stop operation instruction from the AP, and the communication device 1500 is further configured to stop communication on the direct link after receiving the stop operation instruction.

[0068] Further, the circuit 1514 (e.g., at least one transmission signal generating unit 1508 of the circuit 1514) may be further configured to generate an ADDTS request frame including information identifying the direct link, the wireless transmitter 1502 may be further configured to transmit the generated ADDTS request frame to the AP to request the AP to set up a traffic stream for the direct link, the wireless receiver 1504 may be further configured to receive an ADDTS response frame from the AP confirming that the traffic stream has been set up, and the wireless transmitter 1502 may be further configured to transmit data frames belonging to the traffic stream to the other communication device.

[0069] For example, the communication device 1500 may be a STA, and the wireless receiver 1504 may receive a trigger frame from an AP during operation. The wireless transmitter 1502 may transmit one or more data frames to another communication device over a direct link after receiving the trigger frame. The trigger frame may be, for example, a TDLS trigger frame. The trigger frame may include information indicating a MAC address, an authorized access category (AC), and a maximum transmit power level of the other communication device. The one or more data frames are transmitted to the MAC address and based on a traffic identifier (TID) specified in the authorized AC or a higher AC, the one or more data frames are transmitted at a transmit power level lower than the maximum transmit power level. The wireless transmitter 1502 may also be configured to periodically transmit a buffer status report frame to the AP, the buffer status report frame corresponding to the TID and further including information indicating the direct link, to report the size of buffered data addressed to the other communication device.

[0070] For example, the communication device 1500 may be a STA configured to wirelessly communicate with an AP, and the circuit 1514 (e.g., at least one transmit signal generator 1508 of the circuit 1514), in operation, may generate a TDLS RTS frame including information indicating another communication device. The wireless transmitter 1502, in operation, may transmit the generated TDLS RTS frame to the AP to request a TXOP (transmit opportunity) for TDLS transmission with the other communication device. The wireless receiver 1504, in operation, may receive a TDLS CTS frame from the AP, and the wireless transmitter 1502 is further configured to, after receiving the TDLS CTS frame, transmit one or more data frames to the other communication device over the TDLS direct link within the requested TXOP.

[0071] For example, the communications device 1500 may be an AP configured to wirelessly communicate with a communications device over a first channel, and the wireless receiver 1504, in operation, may receive a channel grant request frame from the communications device requesting use of a second channel, different from the first channel, for direct link communications with another communications device. After receiving the channel grant request frame, the circuit 1514, in operation, may determine from a frequency coordination database whether the second channel may be used by the communications device and the other communications device. The circuit 1514 (e.g., at least one transmit signal generator 1508 of the circuit 1514) may be further configured to generate a channel grant response frame including information indicative of the determination. The wireless transmitter 1502, in operation, may transmit the channel grant response frame to the communications device configured to communicate over a direct link with the other communications device over the second channel based on the determination.

[0072] The frequency adjustment database may be, for example, an AFC database. The channel use grant response frame further includes information indicating a maximum transmission power level and a validity period for using the second channel, and communication between the communication device and the other communication device on the direct link is stopped upon expiration of the validity period.

[0073] Additionally, the circuit 1514 (e.g., at least one transmit signal generator 1508 of the circuit 1514) may be further configured to generate a stop operation instruction frame. The wireless transmitter 1502 may be further configured to transmit the generated stop operation instruction to the communication device to instruct the communication device to stop communication on the direct link.

[0074] Furthermore, the circuit 1514 (e.g., at least one transmission signal generating unit 1508 of the circuit 1514) may be further configured to generate a trigger frame including information identifying the other communication device, and the wireless transmitter 1502 may be further configured to transmit the generated trigger frame to the communication device, and the communication device may be configured to transmit one or more data frames to the other communication device over the direct link after receiving the trigger frame. The trigger frame may be, for example, a TDLS (TDLS Trigger) trigger frame.

[0075] For example, the communications device 1500 may be an AP configured to wirelessly communicate with a communications device, and the wireless receiver 1504, in operation, may receive a TDLS RTS frame from the communications device, the TDLS RTS frame including information indicating the other communications device and requesting a TXOP from the AP for TDLS transmission with the other communications device. The circuit 1514 (e.g., at least one transmit signal generator 1508 of the circuit 1514), in operation, may generate a TDLS CTS frame. The wireless transmitter 1502, in operation, may transmit the TDLS CTS frame to the communications device, and the communications device is configured to transmit one or more data frames in the requested TXOP to the other communications device over a TDLS direct link after receiving the TDLS CTS frame.

[0076] FIG. 16 is a diagram 1600 illustrating a flow of a communication method, according to various embodiments. In step 1602, a channel grant request frame may be generated, the channel grant request frame including information indicating a communication device, another communication device, and a second channel different from the first channel. In step 1604, the generated channel grant request frame may be transmitted to an AP to request permission from the AP to use the second channel for direct link communication with the other communication device. In step 1606, a channel grant response frame may be received from the AP granting use of the second channel. In step 1608, after receiving the channel grant response frame, communication with the other communication device may be initiated over the direct link on the second channel.

[0077] Figure 17 illustrates a configuration of a communications device 1700, e.g., a communications apparatus such as a STA, according to various embodiments. Similar to the schematic example of a communications apparatus shown in Figure 15, the communications device 1700 in the schematic example of Figure 17 includes at least one antenna 1702 with at least one wireless transmitter and at least one wireless receiver (for simplicity, the wireless transmitter and receiver are not depicted in Figure 17), and circuitry 1704. The circuitry 1704 may include at least one controller or CPU 1706, which is used to perform the tasks it is designed to perform (including controlling communications with other communications apparatuses, such as other STAs or APs), with the assistance of software and hardware.

[0078] The circuit 1704 may further include a location determination module 1708 that determines the location of the communication device 1700, which may include latitude and longitude information for its geolocation position. In some regulatory domains, location information may be used by an AFC system to determine frequency channels that can be used by a STA for direct link communications. The circuit 1704 may further include a channel selection module 1710 that selects channels to use for direct links with other STAs and tracks the channel usage validity period for each channel. This module may also process channel usage grant responses from associated APs regarding channel usage for the direct link. The circuit 1704 may further include a direct link record module 1712 that maintains relevant information regarding the direct link and corresponding traffic, such as the channel assigned to the direct link and its validity period, traffic stream parameters assigned to the direct link, various direct link buffer statuses, and other similar data.

[0079] Figure 18 illustrates a configuration of a communications device 1800, e.g., an AP, according to various embodiments. Similar to the schematic example of a communications apparatus shown in Figure 15, the communications device 1800 in the schematic example of Figure 18 includes at least one antenna 1802 with at least one wireless transmitter and at least one wireless receiver (for simplicity, the wireless transmitter and receiver are not depicted in Figure 18), and circuitry 1804. The circuitry 1804 may include at least one controller or CPU 1806, which is used to perform the tasks it is designed to perform (including controlling communications with other communications devices, such as STAs or other APs), with the aid of software and hardware.

[0080] The circuit 1804 may further include an AFC system interface module 1814 that maintains information necessary for communicating with the AFC system and acts as a gateway to the AFC system and AFC database. Actual communication with the AFC system may be via a wired interface. The circuit 1804 may further include a location determination module 1808 that determines the location of the AP device, which may include latitude and longitude information for the AP's geolocation position and the AP's position and orientation above the ground. The location information may be used by the AFC system to determine frequency channels that may be used by the AP and its associated STAs. The circuit 1804 may further include a channel management module 1810 that manages channels used by STAs associated with the AP (which may include sending enable signals on the channels, tracking channel usage validity periods, etc.). This module may also process channel use permission requests from associated STAs regarding the use of the channels for direct links and interact with the AFC system interface module. The circuit 1804 may further include a direct link record module 1812 that maintains relevant information regarding the direct link and corresponding traffic, such as the channel assigned to the direct link and its validity period, traffic stream parameters assigned to the direct link, buffer status of various direct links, and other similar data.

[0081] FIG. 19 illustrates the configuration of a multi-band device, e.g., a STA, according to various embodiments. A multi-band device may be comprised of multiple STAs, each corresponding to a different frequency band. For example, if a multi-band device supports both the 5 GHz and 6 GHz bands, it may appear to include a 5 GHz STA (e.g., STA 1902) and a 6 GHz STA (e.g., STA 1904), each with its own MAC and PHY layers and associated entities. Each STA may have a terminal management entity that can access the MAC and PHY layers of each band via its respective MAC Layer Management Entity (MLME) and PHY Management Entity (PLME). Each STA's MAC Service Access Point (SAP) provides an interface to band-specific MAC and PHY sublayers for higher layer protocols. In a traditional 802.11 network, even if both AP and non-AP devices are multi-band devices, they are viewed as separate STAs on each frequency band, with 5 GHz non-AP STAs required to associate with 5 GHz AP STAs and 6 GHz non-AP STAs required to associate with 6 GHz AP STAs. In a scenario where the AP is a single-band device (e.g., an 802.11ac AP) and operates only in the 5 GHz band, the non-AP device may not be able to use its own 6 GHz STA to communicate with the AP. However, two such non-AP devices can communicate in the 6 GHz band by establishing a TDLS link between the corresponding 6 GHz STAs. In such a case, the 5 GHz non-AP STA can request permission from the AP to use a channel in the 6 GHz band for direct link communication with other 6 GHz STAs on behalf of the 6 GHz STA. If the MAC address used by the 6 GHz STA is different from the MAC address used by the 5 GHz STA, the AP may keep a record of the 6 GHz MAC address to track the direct link.

[0082] EHT APs and most EHT non-AP STAs are expected to be multi-band devices capable of operating on multiple frequency bands. Traditionally, each frequency band has its own MAC and PHY layers and associated entities, and in 802.11, the entities associated with each frequency band are treated as separate STAs, even if they are housed within the same physical device. Alternatively, regardless of the number of frequency bands a multi-band device can operate on, each device may be represented by a single unified MAC address and communication links on various frequencies differentiated by band IDs and channel numbers.

[0083] Thus, embodiments of the present disclosure provide an advanced communication system, communication method, and communication device that enable enhanced direct link communication. While most of the references in this disclosure relate to IEEE 802.11 networks and devices, the present disclosure may be similarly applied to cellular systems for device-to-device communication (D2D) communication, for example, in LTE-Advanced networks or upcoming 5G networks. Before initiating direct link communication on a channel in the 6 GHz band between two cellular UEs, a User Equipment (UE) can request a channel grant for D2D communication with other nearby UEs from a serving base station (e.g., eNodeB) by sending a channel grant request to the base station. Upon receiving the channel grant request from the UE, the base station checks an AFC database (e.g., via an AFC system) for the availability of the requested channel. If successful, the base station can send a channel grant response with a status of SUCCESS to the UE to inform it that the requested channel is available for D2D communication. The UE can then begin using the channel for D2D communication with other UEs.

[0084] The present disclosure can be realized by software, hardware, or software in conjunction with hardware. Each functional block described in the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit. Each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. An LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the level of integration, an LSI may be referred to as an IC, system LSI, super LSI, or ultra LSI. The integration method is not limited to LSIs; it may also be realized by dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, a field programmable gate array (FPGA), which can be programmed after LSI fabrication, or a reconfigurable processor, which allows the connections and settings of circuit cells within an LSI to be reconfigured, may also be used. The present disclosure may be realized as digital or analog processing. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0085] The present disclosure may be implemented in any type of apparatus, device, or system having a communication function (collectively referred to as a communication apparatus).

[0086] A communications device may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both. The radio transceiver (transmitter, receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like.

[0087] Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0088] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0089] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0090] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0091] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0092] Although some features of various embodiments are described with reference to devices, corresponding features also apply to the methods of various embodiments, and vice versa.

[0093] As shown in the particular embodiments, those skilled in the art will appreciate that numerous changes and / or modifications may be made to the present disclosure without departing from the spirit or scope of the disclosure as broadly described. The embodiments herein are therefore to be considered in all respects as illustrative and not restrictive.

Claims

1. a circuit for generating a single trigger frame; a transmitter that transmits the one trigger frame to a first station at a transmit opportunity (TXOP); Equipped with the single trigger frame includes information about multiple data frames that the first station transmits to a second station at different times within the portion of the TXOP; the transmitter does not transmit a trigger frame in the portion of the TXOP. Access point.

2. the second station is a peer station in a peer-to-peer link with the first station; The access point of claim 1 .

3. the first station receives a block acknowledgment frame from the second station within the portion of the TXOP; The access point of claim 1 .

4. the plurality of data frames are transmitted at a transmission power lower than a predetermined transmission power level; The access point of claim 1 .

5. The trigger frame contains only one User Info field addressed to an individual station. The access point of claim 1 .

6. The trigger frame includes a User Info field addressed to the first station, and the User Info field includes an AID 12 subfield in which the AID of the first station is set. The access point of claim 1 .

7. Some of the data frames are transmitted without a preceding trigger frame. The access point of claim 1 .

8. the plurality of data frames are transmitted by scheduled transmission; The access point of claim 1 .

9. generating a single trigger frame; transmitting the one trigger frame to a first station at a transmit opportunity (TXOP); Including, the single trigger frame includes information about multiple data frames that the first station transmits to a second station at different times within the portion of the TXOP; not transmitting a trigger frame in the portion of the TXOP; A communication method, including:

10. generating a single trigger frame; transmitting the one trigger frame to a first station at a transmit opportunity (TXOP); Control the the single trigger frame includes information about multiple data frames that the first station transmits to a second station at different times within the portion of the TXOP; not transmitting a trigger frame in the portion of the TXOP; An integrated circuit that controls

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