Wireless communication method and wireless communication terminal using basic service set identification information determination of received frame

Abstract

To provide a wireless communication terminal and wireless communication method that can efficiently signal discontinuous channel allocation information.SOLUTION: A wireless communication method using basic service set identification information in a wireless LAN comprises: a wireless communication terminal extracting partial Association ID (AID) information and group ID information from a preamble of a received wireless communication frame (S2710); when the extracted group ID information is equal to a predetermined value, checking whether at least some information of the extracted partial AID matches a partial Basic Service Set (BSS) color announced to the terminal (S2730, S2740); and determining whether the received frame is an intra-BSS frame or an inter-BSS frame according to whether at least some information of the partial AID matches the partial BSS color (S2732, S2734, S2742, S2744).SELECTED DRAWING: Figure 27

Description

[Technical field]

[0001] The present invention relates to a wireless communication method and a wireless communication terminal using basic service set identification information determination of a received frame, and more particularly to a wireless communication method and a wireless communication terminal that perform an operation depending on the determination result of whether a received frame is an intra-BSS frame or an inter-BSS frame. [Background technology]

[0002] Recently, as the use of mobile devices has become more widespread, wireless LAN technology that can provide them with high-speed wireless Internet services has been attracting attention. Wireless LAN technology is a technology that enables mobile devices such as smartphones, smart pads, laptop PCs, portable multimedia players, embedded devices, etc. to wirelessly connect to the Internet at home, in business, or in specific service areas based on short-distance wireless communication technology.

[0003] Since IEEE (Institute of Electronics Engineers) 802.11 supported the initial wireless LAN technology using the 2.4GHz frequency band, it has put into practical use or is currently developing various technology standards. First, IEEE 802.11b uses the 2.4GHz frequency band and supports a maximum communication speed of 11Mbps. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses the 5GHz frequency band instead of the 2.4GHz band, reducing the impact of interference compared to the significantly more congested 2.4GHz frequency band, and uses OFDM technology to increase communication speeds to a maximum of 54Mbps. However, IEEE 802.11a has the disadvantage of a shorter communication distance than IEEE 802.11b. IEEE 802.11g, like IEEE 802.11b, uses the 2.4GHz band and achieves a maximum transmission speed of 54Mbps and satisfies backward compatibility, which has attracted considerable attention, but it also has an advantage over IEEE 802.11a in communication distance.

[0004] IEEE 802.11n is a technical standard established to overcome the communication speed limitations that have been pointed out as a weakness of wireless LAN. The purpose of IEEE 802.11n is to increase the speed and reliability of the network and to extend the operating distance of the wireless network. In detail, IEEE 802.11n supports a high throughput (HT) of up to 540Mbps or more in data processing speed, and is based on MIMO (Multiple Inputs and Multiple Outputs) technology that uses multiple antennas on both the transmitting and receiving ends to minimize transmission errors and optimize data speed. This standard also uses a coding method that transmits multiple duplicate copies to increase data reliability.

[0005] As the use of wireless LANs becomes more widespread and applications using them become more diverse, the need for new wireless LAN systems to support data throughput rates (Very High Throughput, VHT) higher than those supported by IEEE 802.11n is emerging. Among them, IEEE 802.11ac supports wide bandwidth (80MHz~160MHz) at 5GHz frequency. Although the IEEE 802.11ac standard is defined only in the 5GHz band, it is expected that initial 11ac chipsets will also support operation in the 2.4GHz band for backward compatibility with existing 2.4GHz band products. Theoretically, this standard allows multi-station wireless LAN speeds of at least 1Gbps and maximum single link speeds of at least 500Mbps. This is done by extending the air interface concepts accepted by 802.11n, such as wider radio frequency bandwidth (up to 160MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high density modulation (up to 256QAM). Also, there is IEEE 802.11ad, a method of transmitting data using the 60GHz band instead of the conventional 24GHz / 5GHz. IEEE 802.11ad is a transmission standard that uses beamforming technology to provide speeds of up to 7Gbps, and is suitable for streaming large amounts of data and high bitrate videos such as uncompressed HD video. However, the 60GHz frequency band has the disadvantage that it is difficult to pass through obstacles and can only be used between devices in close proximity.

[0006] Meanwhile, discussions are currently ongoing to provide high-efficiency and high-performance wireless LAN communication technology in high-density environments as the standard for next-generation wireless LANs after 802.11ac and 802.11ad. In other words, next-generation wireless LAN environments should provide high-frequency-efficient communication both indoors and outdoors in the presence of high-density stations and APs (Access Points), and various technologies are required to realize this. Summary of the Invention

[0007] According to an embodiment of the present invention, discontinuous channel allocation information can be efficiently signaled.

[0008] The present invention also has the objective of setting rules for the allocation of AIDs of STAs within a BSS.

[0009] Another object of the present invention is to prevent ambiguity that may occur during intra / inter-BSS determination using partial AID information of a VHT PPDU. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a wireless communication method for a terminal and a wireless communication terminal as follows.

[0011] First, according to an embodiment of the present invention, a base wireless communication terminal is provided, which includes a processor and a communication unit, and the processor assigns an AID (Association ID) to at least one terminal associated with the base wireless communication terminal, and the pre-set N-bit(s) of the AID is determined based on a value obtained by subtracting an N-bit value based on a BSSID from a partial BSS (Basic Service Set) color value.

[0012] In addition, according to an embodiment of the present invention, a wireless communication method for a base wireless communication terminal includes a step of assigning an AID to at least one terminal associated with the base wireless communication terminal, and a step of transmitting the assigned AID information to a terminal associated with the base wireless communication terminal, wherein the predetermined N-bit(s) of the AID is determined based on a value obtained by subtracting an N-bit value based on a BSSID from a partial BSS color value.

[0013] The partial BSS color value is the minimum or maximum significant N-bit(s) value of a BSS color, and the BSSID-based N-bit value is the exclusive OR of a first pre-configured N-bit(s) of a BSSID and a second pre-configured N-bit(s) of a BSSID.

[0014] According to an embodiment of the present invention, said N is 4.

[0015] According to an embodiment of the present invention, the AID satisfies the following formula:

[0016]

number

[0017] Here, BCB is the BSS color, BSSID is the BSS identifier, and N=4.

[0018] When the base wireless communication terminal transmits a VHT PPDU to a first terminal, the processor sets a partial AID using the AID information of the first terminal determined by the subtraction operation and a K-bit value based on the BSSID, and inserts the set partial AID information into the preamble of the VHT PPDU to transmit it.

[0019] The preset N-bit(s) of the partial AID indicates the partial BSS color value by offsetting the BSSID-based N-bit value and the BSSID-based K-bit value.

[0020] The partial AID information is inserted into the VHT-SIG-A of the VHT PPDU.

[0021] According to another embodiment of the present invention, there is provided a wireless communication terminal including a processor and a communication unit, the processor receiving a wireless communication frame via the communication unit, extracting partial AID information and group ID information from a preamble of the VHT PPDU if the received frame is a VHT PPDU, and if the extracted group ID information is a preset value, checking whether at least a portion of the information of the extracted partial AID matches a partial BSS color known to the terminal, and determining whether the received frame is an intra-BSS frame or an inter-BSS frame depending on whether at least a portion of the information of the partial AID matches the partial BSS color.

[0022] According to yet another embodiment of the present invention, there is provided a wireless communication method for a wireless communication terminal, the method including the steps of: receiving a wireless frame; if the received frame is a VHT PPDU, extracting partial AID information and group ID information from a preamble of the VHT PPDU; if the extracted group ID information is a preset value, checking whether at least a portion of the extracted partial AID information matches a partial BSS color known to the terminal; and determining whether the received frame is an intra-BSS frame or an extra-BSS frame depending on whether at least a portion of the partial AID information matches the partial BSS color.

[0023] The partial AID is determined using a K-bit value based on the AID assigned to the intended recipient of the VHT PPDU and the BSSID of the BSS to which the recipient is associated, and if the BSS to which the terminal belongs applies an AID allocation rule using partial BSS color bits, the pre-defined N-bit(s) of the AID assigned from the BSS to which the terminal belongs is determined using a partial BSS color value known to the terminal and an N-bit value based on the BSSID of the BSS to which the terminal belongs, where N has the same value as K.

[0024] The pre-configured N-bit(s) of the AID assigned by the BSS to which the terminal belongs is determined based on a value obtained by subtracting an N-bit value based on the BSSID of the BSS to which the terminal belongs from a partial BSS color value known to the terminal.

[0025] If the BSS to which the receiver is associated applies an AID allocation rule using partial BSS color bits, the pre-configured bit(s) of the partial AID indicates a partial BSS color value known to the receiver by offsetting a K-bit value based on the BSSID and an N-bit value based on the BSSID of the BSS to which the receiver is associated.

[0026] The partial BSS color value is the minimum or maximum significant N-bit(s) value of a BSS color, and the BSSID-based N-bit value is the exclusive OR of the first pre-configured N-bit(s) of the BSSID and the second pre-configured N-bit(s) of the BSSID.

[0027] According to an embodiment of the present invention, said N is 4.

[0028] According to an embodiment of the present invention, the AID satisfies the following formula:

[0029]

number

[0030] Here, BCB is the BSS color, BSSID is the BSS identifier, and N=4.

[0031] The preset value of group ID information indicates that the frame is a downstream frame.

[0032] If the received frame is determined to be an intra-BSS frame, the processor performs a first operation, and if the received frame is determined to be an inter-BSS frame, the processor performs a second operation.

[0033] If the received frame is determined to be an intra-BSS frame, the processor determines whether to occupy a channel based on a first CCA threshold, and if the received frame is determined to be an inter-BSS frame, the processor determines whether to occupy a channel based on both the first CCA threshold and a second CCA threshold distinct from the first CCA threshold.

[0034] The second CCA threshold value is equal to or greater than the first CCA threshold value.

[0035] If the received frame is determined to be an intra-BSS frame, the processor sets or updates a first NAV (Network Allocation Vector), and if the received frame is determined to be an inter-BSS frame, the processor sets or updates a second NAV. Effect of the Invention

[0036] According to an embodiment of the present invention, at least a portion of the information in the partial AID of the VHT PPDU indicates a partial BSS color value, so that an efficient intra / inter-BSS frame determination can be performed.

[0037] More specifically, according to an embodiment of the present invention, a terminal receiving a VHT PPDU can determine whether it is an intra-BSS frame or an inter-BSS frame using partial AID information without the need to acquire additional information or perform calculations.

[0038] Furthermore, according to an embodiment of the present invention, if a received frame is determined to be an inter-BSS frame, a spatial reuse operation can be performed to efficiently use radio resources.

[0039] According to an embodiment of the present invention, in a contention-based channel access system, it is possible to increase the utilization rate of overall resources and improve the performance of a WLAN system. [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention. [Diagram 2] FIG. 11 is a diagram showing a wireless LAN system according to another embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram showing a configuration of a station according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing the configuration of an access point according to an embodiment of the present invention. [Diagram 5] 1 is a diagram illustrating a process in which a STA sets up a link with an AP. [Figure 6] FIG. 1 is a diagram illustrating a CSMA (Carrier Sense Multiple Access) / CA (Collision Avoidance) method used in wireless LAN communication. [Figure 7] A diagram showing the structures of VHT-SIG-A1 and VHT-SIG-A2 according to one embodiment of the present invention. [Figure 8] 1 is a table showing a method for setting a group ID and partial AIDs according to an embodiment of the present invention. [Figure 9] FIG. 2 illustrates a non-legacy element format according to one embodiment of the present invention. [Figure 10] FIG. 2 is a diagram illustrating a partial AID calculation process according to an embodiment of the present invention. [Figure 11] 4 is a diagram illustrating in more detail a partial AID calculation process according to an embodiment of the present invention. FIG. [Figure 12] FIG. 2 is a diagram illustrating a method for determining whether an intra-BSS frame or an inter-BSS frame is present according to a first embodiment of the present invention. [Figure 13]FIG. 11 is a diagram illustrating a method for determining whether an intra-BSS frame or an inter-BSS frame is present according to a second embodiment of the present invention. [Figure 14] 4A and 4B are diagrams illustrating a process of calculating a reference value for determining an intra / inter-BSS frame and a process of calculating a partial AID according to an embodiment of the present invention. [Figure 15] A diagram showing a non-legacy element format according to another embodiment of the present invention. [Figure 16] A diagram showing a method for signaling partial BSS color bit number information and ambiguity information according to another embodiment of the present invention. [Figure 17] FIG. 11 is a diagram showing AID allocation information and a non-legacy element format according to a second embodiment of the present invention. [Figure 18] FIG. 11 is a diagram illustrating an AID allocation method according to a third embodiment of the present invention. [Figure 19] FIG. 13 is a diagram illustrating an AID allocation method according to a fourth embodiment of the present invention. [Figure 20] FIG. 13 is a diagram illustrating an AID allocation method according to a fifth embodiment of the present invention. [Figure 21] FIG. 13 is a diagram illustrating an AID allocation method according to a fifth embodiment of the present invention. [Figure 22] FIG. 11 is a diagram illustrating a method for determining whether a frame is an intra-BSS frame or an inter-BSS frame according to a third embodiment of the present invention. [Diagram 23] A diagram showing a non-legacy element format according to yet another embodiment of the present invention. [Figure 24] FIG. 13 is a diagram illustrating an AID allocation method according to a sixth embodiment of the present invention. [Diagram 25] A diagram showing a non-legacy element format according to yet another embodiment of the present invention. [Figure 26] FIG. 13 is a diagram illustrating an AID allocation method according to a seventh embodiment of the present invention. [Figure 27] FIG. 13 is a diagram illustrating a method for determining whether an intra-BSS frame or an inter-BSS frame is present according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] The terms used in this specification are selected as general terms that are currently widely used as much as possible in consideration of the functions of the present invention, but this may vary depending on the intentions, customs, or the emergence of new technologies of the engineers in the relevant technical field. In addition, in certain cases, the applicant may arbitrarily select terms, and in such cases, the meanings of the terms will be described in the description of the relevant invention. Therefore, it is clear that the terms used in this specification should be interpreted not simply as terms, but based on the substantial meanings of the terms and the contents of this specification as a whole.

[0042] Throughout the specification, when a component is "connected" to another component, this includes not only when it is "directly connected" to another component, but also when it is "electrically connected" with another component in between. Furthermore, when a component "includes" a specific component, this means that it may further include the other component, not excluding the other component, unless otherwise specified to the contrary. In addition, limitations such as "greater than" or "less than" based on a specific critical value may be appropriately replaced with "more than" or "less than" depending on the embodiment.

[0043] This application claims priority based on Korean Patent Application Nos. 10-2016-0040551, 10-2016-0093812, and 10-2016-0102229, and the examples and descriptions in each of the above applications which are the basis of priority are incorporated herein by reference in their entirety.

[0044] FIG 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention. The wireless LAN system includes one or more Basic Service Sets (BSS), where a BSS is a set of devices that can successfully synchronize and communicate with each other. Generally, BSSs are classified into infrastructure BSSs and independent BSSs (IBSSs), and FIG 1 shows an infrastructure BSS.

[0045] As shown in FIG. 1, an infrastructure BSS (BSS1, BSS2) includes one or more stations (STA1, STA2, STA3, STA4, STA5), access points (PCP / AP-1, PCP / AP-2) which are stations providing distribution services, and a distribution system (DS) that connects multiple access points (PCP / AP-1, PCP / AP-2).

[0046] A station (STA) is any device including a medium access control (MAC) and a physical layer interface for a wireless medium according to the IEEE 802.11 standard, and in a broad sense includes not only non-AP stations but also APs. In this specification, the term "terminal" refers to either a non-AP or an AP, or both. A station for wireless communication includes a processor and a communication unit, and further includes a user interface unit and a display unit, etc., depending on the embodiment. The processor generates frames to be transmitted through a wireless network, processes frames received through the wireless network, and performs various other processes for controlling the station. The communication unit is functionally connected to the processor and transmits and receives frames through the wireless network for the station. In the present invention, the term "terminal" is used to include a user equipment (UE).

[0047] An access point (AP) is an entity that provides a connection to a distribution system DS via a wireless medium for a station associated therewith. In an infrastructure BSS, communication between non-AP stations is generally performed via the AP, but when a direct link is set up, direct communication is possible between non-AP stations. Meanwhile, in the present invention, AP is used as a concept including a personal BSS coordination point (PCP), but in a broad sense, AP includes all concepts such as a central controller, a base station (BS), a node B, a base transceiver system (BTS), or a site controller. In the present invention, AP is also referred to as a base wireless communication terminal, but in a broad sense, the base wireless communication terminal is used as a term including an AP, a base station, an eNodeB (eNB), and a transmission point TP. In addition, the base wireless communication terminal includes various types of wireless communication terminals that allocate communication medium resources and perform scheduling in communication with a plurality of wireless communication terminals.

[0048] A plurality of infrastructure BSSs are connected to each other via a distribution system DS. In this case, a plurality of BSSs connected to each other via the distribution system is called an Extended Service Set (ESS).

[0049] 2 is a diagram showing an independent BSS, which is a wireless LAN system according to another embodiment of the present invention, in which the same or corresponding parts in the embodiment of FIG. 2 are the same as or correspond to the embodiment of FIG.

[0050] BSS3 shown in Figure 2 is an independent BSS and does not include an AP, so all stations (STA6, STA7) are not connected to an AP. An independent BSS is not allowed to connect to a distribution system and forms a self-contained network. In an independent BSS, each station (STA6, STA7) is directly connected to each other.

[0051] 3 is a block diagram showing a configuration of a station 100 according to an embodiment of the present invention. As shown in the figure, the station 100 according to the embodiment of the present invention includes a processor 110, a communication unit 120, a user interface unit 140, a display unit 150, and a memory 160.

[0052] First, the communication unit 120 transmits and receives wireless signals such as wireless LAN packets, and is provided inside or outside the station 100. According to an embodiment, the communication unit 120 includes at least one communication module using different frequency bands. For example, the communication unit 120 includes communication modules using different frequency bands such as 2.4 GHz, 5 GHz, and 60 GHz. According to an embodiment, the station 100 includes a communication module using a frequency band of 6 GHz or more and a communication module using a frequency band of 6 GHz or less. Each communication module performs wireless communication with an AP or an external station according to the wireless LAN standard of the frequency band supported by the corresponding communication module. The communication unit 120 may operate only one communication module at a time or operate multiple communication modules simultaneously according to the performance and requirements of the station 100. When the station 100 includes multiple communication modules, each communication module may be provided in an independent form, or multiple modules may be integrated and provided on one chip. In an embodiment of the present invention, the communication unit 120 represents an RF (Radio Frequency) communication module that processes RF signals.

[0053] Next, the user interface 140 includes various types of input / output means provided in the station 100. That is, the user interface unit 140 receives user input using various input means, and the processor 110 controls the station 100 based on the received user input. Also, the user interface unit 140 performs output based on a command from the processor 110 using various output means.

[0054] Then, the display unit 150 outputs an image on a display screen. The display unit 150 outputs various display objects such as a user interface based on the contents performed by the processor 110 or a control command of the processor 110. The memory 160 also stores control programs used by the station 100 and various data associated therewith. Such control programs include connection programs required for the station 100 to connect to an AP or an external station.

[0055] The processor 110 of the present invention executes various commands or programs to process data within the station 100. The processor 110 also controls each unit of the station 100 and controls transmission and reception of data between the units. According to an embodiment of the present invention, the processor 110 executes a program for connection with an AP stored in the memory 160 and receives a communication setup message transmitted by the AP. The processor 110 also reads information on the priority conditions of the station 100 included in the communication setup message and requests a connection to the AP based on the information on the priority conditions of the station 100. The processor 110 of the present invention may refer to a main control unit of the station 100, or may refer to a control unit for individually controlling some components of the station 100, for example, the communication unit 120, depending on the embodiment. That is, the processor 110 may be a modem that modulates and demodulates a wireless signal transmitted and received from the communication unit 120, or a modulator and / or demodulator. The processor 110 controls various operations of transmitting and receiving wireless signals of the station 100 according to an embodiment of the present invention. A detailed embodiment of the present invention will be described later.

[0056] The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separate blocks are used to logically distinguish the elements of the device. Thus, the above-mentioned device elements may be mounted on one chip or multiple chips depending on the design of the device. For example, the processor 110 and the communication unit 120 may be integrated and embodied on one chip, or may be embodied on separate chips. In addition, in an embodiment of the present invention, some components of the station 100, such as the user interface unit 140 and the display unit 150, may be selectively provided in the station 100.

[0057] 4 is a block diagram showing a configuration of an AP 200 according to an embodiment of the present invention. As shown in the figure, the AP 200 according to the embodiment of the present invention includes a processor 210, a communication unit 220, and a memory 260. In FIG. 4, a duplicated description of parts of the configuration of the AP 200 that are the same as or correspond to the configuration of the station 100 in FIG. 3 will be omitted.

[0058] Referring to FIG. 4, the AP 200 according to the present invention includes a communication unit 220 for operating a BSS in at least one frequency band. As described in the embodiment of FIG. 3, the communication unit 220 of the AP 200 also includes a plurality of communication modules using different frequency bands. That is, the AP 200 according to the embodiment of the present invention includes at least two communication modules among different frequency bands, for example, 2.4 GHz, 5 GHz, and 60 GHz. Preferably, the AP 200 includes a communication module using a frequency band of 6 GHz or more and a communication module using a frequency band of 6 GHz or less. Each communication module performs wireless communication with a station according to the WLAN standard of the frequency band supported by the corresponding communication module. The communication unit 220 may operate only one communication module at a time or operate multiple communication modules simultaneously according to the performance and requirements of the AP 200. In the embodiment of the present invention, the communication unit 220 represents an RF communication module for processing RF signals.

[0059] Next, the memory 260 stores control programs used in the AP 200 and various data associated therewith. Such control programs include a connection program for managing the connection of stations. Also, the processor 210 controls each unit of the AP 200 and controls transmission and reception of data between the units. According to an embodiment of the present invention, the processor 210 executes a program for connection with a station stored in the memory 260 and transmits a communication setting message to one or more stations. At this time, the communication setting message includes information regarding connection priority conditions of each station. Also, the processor 210 performs connection setting in response to a connection request of a station. According to an embodiment, the processor 210 is a modem or a modulation / demodulation unit that modulates and demodulates a wireless signal transmitted and received from the communication unit 220. The processor 210 controls various operations of transmitting and receiving wireless signals of the AP 200 according to an embodiment of the present invention. A detailed embodiment thereof will be described later.

[0060] FIG. 5 is a diagram illustrating a process in which a STA establishes a link with an AP.

[0061] 5, the link between the STA 100 and the AP 200 is set up through three steps: scanning, authentication, and association. First, the scanning step is a step in which the STA 100 acquires connection information of the BSS operated by the AP 200. There are two methods for performing scanning: a passive scanning method in which the STA 100 acquires information using only a beacon message S101 periodically transmitted by the AP 200, and an active scanning method in which the STA 100 transmits a probe request to the AP S103, receives a probe response from the AP S105, and acquires connection information.

[0062] The STA 100 that has successfully received wireless connection information in the scanning step transmits an authentication request (S107a), receives an authentication response from the AP 200 (S107b), and performs an authentication step. After the authentication step is performed, the STA 100 transmits an association request (S109a), receives an association response from the AP 200, and performs an association step (S109b). In this specification, association basically means wireless association, but the present invention is not limited thereto, and association in a broad sense includes both wireless association and wired association.

[0063] Meanwhile, an 802.1X-based authentication step S111 and an IP address acquisition step S113 via DHCP are additionally performed. In Fig. 5, the server 300 is a server that processes 802.1X-based authentication with the STA 100, and may be physically connected to the AP 200 or may exist as a separate server.

[0064] FIG. 6 is a diagram showing the CSMA / CA method used in wireless LAN communications.

[0065] A terminal performing wireless LAN communication checks whether a channel is occupied by performing carrier sensing before transmitting data. If a wireless signal of a certain strength or more is detected, the channel is determined to be occupied, and the terminal delays access to the channel. This process is called Clear Channel Assessment (CCA), and the level that determines whether the signal is detected is called the CCA threshold. If a wireless signal of a strength greater than the CCA threshold received by a terminal is addressed to the terminal as a receiver, the terminal processes the received wireless signal. On the other hand, if no wireless signal is detected on the channel or a wireless signal of a strength less than the CCA threshold is detected, the channel is determined to be idle.

[0066] When the channel is determined to be in an idle state, each terminal having data to transmit performs a backoff procedure after an IFS (Inter Frame Space) time according to the status of each terminal, for example, an AIFS (Arbitration IFS) or a PIFS (PCF IFS). In some embodiments, the AIFS may be used as a replacement for the conventional DIFS (DCF IFS). Each terminal waits while decreasing a slot time of a random number determined for the corresponding terminal during an interval of the idle state of the channel, and a terminal that has exhausted all of the slot time attempts to access the corresponding channel. The period during which each terminal performs a backoff procedure is called a contention window period.

[0067] If a specific terminal succeeds in accessing the channel, the terminal transmits data through the channel. However, if the terminal attempting access collides with another terminal, the colliding terminals are assigned new random numbers and perform a backoff procedure again. According to one embodiment, the random numbers newly assigned to each terminal are determined within a range (2*CW) twice the range (contention window, CW) of the random numbers previously assigned to the terminal. Meanwhile, each terminal performs a backoff again in the next contention window period and attempts access, and at this time, each terminal performs a backoff procedure from the slot time remaining in the previous contention window period. In this manner, each terminal performing wireless LAN communication can avoid collisions with each other on a specific channel.

[0068] 7 is a diagram showing the structures of VHT-SIG-A1 and VHT-SIG-A2 according to an embodiment of the present invention. The preamble of a VHT PPDU (PHY Protocol Data Unit) includes a VHT-SIG-A field, and VHT-SIG-A consists of VHT-SIG-A1 and VHT-SIG-A2. VHT-SIG-A1 and VHT-SIG-A2 convey information required to interpret the VHT PPDU.

[0069] Referring to Figure 7, the VHT-SIG-A1 of a single-user (SU) PPDU includes a 9-bit partial AID field. The partial AID field indicates condensed information for the intended recipient of the corresponding PSDU. The VHT-SIG-A1 Group ID field is set to 0 or 63 for a SU PPDU, and is set to any other value for a multi-user (MU) PPDU. The terminal checks the partial AID (or partial AID and group ID) of the received VHT PPDU, and aborts decoding if the intended recipient of the corresponding PPDU is not the terminal.

[0070] Hereinafter, a partial AID and an AID setting method according to an embodiment of the present invention will be described with reference to the drawings. For convenience of explanation, each formula and symbol is defined as follows. According to an embodiment of the present invention, in each formula, "[]" and "()" may be used interchangeably and have the same meaning.

[0071] -A[b:c] denotes bits b to c of "A". According to an embodiment of the present invention, the first bit of "A" may be 0, and A[b:c] denotes bits b+1 to c+1 of "A".

[0072] -dec(A[b:c]) represents the value of bits b to c of "A" expressed in decimal. In this case, the value of bit b of "A" is scaled to 2^0, and the value of bit c of "A" is scaled to 2^(cb). dec(A[b:c]) and A[b:c] represent essentially the same value, with only the method of expressing information being different.

[0073] -bin[x,N] indicates the value of "x" expressed as an N-bit binary number.

[0074] -B(X) denotes the bit in bit position X.

[0075] -XOR refers to the bitwise exclusive OR.

[0076] -A mod X denotes the result of performing a modulo X operation on "A." In accordance with an embodiment of the present invention, the result of A mod X is a positive number even if A is negative. For example, 5 mod 3 is 2, and -5 mod 3 is 1.

[0077] FIG. 8 is a table illustrating a method for setting a group ID and partial AIDs according to one embodiment of the present invention.

[0078] First, in a PPDU or PSDU directed to an AP, the group ID is set to 0 and the partial AID is set to BSSID[39:47]. The BSSID indicates the identifier of the BSS to which the terminal transmitting the corresponding PPDU or PSDU belongs. In this way, since part of the BSSID information is set as the partial AID of the uplink frame, the partial AID of the uplink frame has BSS identification power.

[0079] Then, in the PPDU or SPDU destined for the mesh STA, the group ID is set to 0 and the partial AID is set to RA[39:47], where RA indicates the recipient address of the corresponding PPDU or PSDU.

[0080] According to an embodiment of the present invention, in the following PPDU or PSDU, the group ID is set to 63 and the partial AID (hereinafter, PAID) is set as shown in the following Equation 1: i) PPDU or PSDU (i.e., downstream frame) transmitted by an AP and directed to a STA associated with the corresponding AP. ii) PPDU or PSDU transmitted by a DLS (Direct Link Setup) STA or a TDLS (Tunneled Direct Link Setup) STA via a direct path to a DLS or TDLS peer STA.

[0081]

number

[0082] That is, the PAID is determined by a combination of the AID information and the BSSID information. More specifically, the PAID is determined based on a value obtained by adding a part of the AID bit value to a part of the BSSID bit exclusive OR. In the process of combining the AID information and the BSSID information, the PAID of the downstream frame may lose its BSS identification capability for STAs that are not the intended recipients according to the AID setting rules. On the other hand, in cases other than those listed above, the group ID is set to 63 and the partial AID is set to 0.

[0083] The group ID information and PAID information thus set are inserted into the VHT-SIG of the VHT PPDU. The AP transmitting the VHT PPDU determines the PAID using the AID information and BSSID information, and transmits the determined PAID information by inserting it into the VHT-SIG. At this time, the AID information indicates a part of the bit value of the AID assigned to the intended recipient of the corresponding PPDU. Also, the BSSID information indicates a value based on the BSSID of the BSS to which the AP transmitting the corresponding PPDU and the recipient belong. The BSSID-based value indicates an exclusive OR of a part of the bits of the BSSID. More specifically, the BSSID-based value indicates an exclusive OR of the first pre-set K-bit(s) and the second pre-set K-bit(s) of the BSSID. As in the embodiment of Equation 1, K is set to 4, the first pre-set K-bits indicate bits from bit 44 to bit 47, and the second pre-set K-bits indicate bits from bit 40 to bit 43. Hereinafter, in the embodiment of the present invention, the BSSID-based value used for setting the PAID is referred to as a "BSSID-based K-bit value". Meanwhile, since the PAID is determined depending on the AID, it may be determined to a different value depending on the AID allocation method.

[0084] When the AP transmits a VHT PPDU to a STA, the AP sets the PAID using the AID information of the STA and a K-bit value based on the BSSID. At this time, the AID of the STA is set according to one of the embodiments of the present invention described below. The AP inserts the set PAID information into the preamble of the VHT PPDU and transmits it. At this time, the PAID information is inserted into the VHT-SIG-A of the VHT PPDU.

[0085] Hereinafter, an AID allocation method according to various embodiments of the present invention will be described with reference to the drawings and equations. The AP allocates an AID to each STA using at least one of the methods of the embodiments described below. According to one embodiment, the AP allocates an AID determined according to the following rules to the VHT STA. The AP also transmits the allocated AID information to the terminal connected to the AP. In each embodiment, a duplicated description will be omitted for parts that are the same as or correspond to the previous embodiments.

[0086] Equation 2 shows an AID allocation method according to a first embodiment of the present invention.

[0087]

number

[0088] Here, N is an integer between 1 and 4.

[0089] According to an embodiment of the present invention, bits from bit 8-N+1 to bit 8 of the AID are set according to the rule of Equation 2. In this case, BSB refers to a partial BSS color or a BSS color. The partial BSS color is notified to the STAs associated with the BSS by the AP operating the corresponding BSS. According to the embodiment of Equation 2, the preset N-bit(s) of the AID are determined using BCB information and BSSID information. The BCB information is a partial BSS color value and indicates the value of the least significant N-bit(s) of the BSS color. However, the present invention is not limited thereto, and the BCB information may indicate the value of the most significant N-bit(s) of the BSS color. The BSSID information refers to a value based on the BSSID of the BSS operated by the AP that assigns the AID. The BSSID-based value indicates an exclusive OR of some bits of the BSSID. More specifically, the BSSID-based value indicates an exclusive OR of a first preset N-bit(s) of the BSSID and a second preset N-bit(s) of the BSSID. According to the embodiment of Equation 2, the first preset N-bit(s) refers to the bit(s) from bit 47-N+1 to bit 47, and the second preset N-bit(s) refers to the bit(s) from bit 43-N+1 to bit 43. Hereinafter, in the embodiment of the present invention, the BSSID-based value used for AID allocation is referred to as a "BSSID-based N-bit value".

[0090] When the AID is assigned in this manner, the preset bits of the PAID determined according to the embodiment of Equation 1, i.e., PAID(8-N+1:8), have BSS discrimination. If the PAID has BSS discrimination, the non-legacy terminal determines whether the corresponding frame is an intra-BSS frame or an extra-BSS frame based on the PAID information of the received frame. In the embodiment of the present invention, the non-legacy terminal refers to a terminal that complies with the next generation wireless LAN standard (i.e., IEEE 802.11ax). In addition, an intra-BSS frame refers to a frame transmitted from a terminal belonging to the same BSS, and an inter-BSS frame refers to a frame transmitted from a terminal belonging to another BSS.

[0091] A non-legacy terminal determines whether a frame is an intra-BSS frame or an inter-BSS frame using information for identifying a BSS, such as a BSS color, a partial BSS color, a MAC address, etc. The partial BSS color refers to the BCB value of Equation 2. According to an embodiment of the present invention, if an AID is assigned according to a specific rule, partial BSS color information is extracted from preset bits of the PAID according to Equation 1. In this case, the preset bits of the PAID refer to the upper N-bits of the PAID, i.e., PAID(8-N+1:8).

[0092] A non-legacy terminal performs different operations depending on whether a received frame is an intra-BSS frame or not. That is, if a received frame is determined to be an intra-BSS frame, the terminal performs a first operation. Also, if a received frame is determined to be an inter-BSS frame, the terminal performs a second operation different from the first operation. According to an embodiment of the present invention, the first and second operations are variously set.

[0093] According to an embodiment, the terminal performs channel access based on different thresholds depending on whether the received frame is an intra-BSS frame. More specifically, if the received frame is determined to be an intra-BSS frame, the terminal accesses the channel based on a first CCA threshold (first operation). That is, the terminal performs CCA based on the first CCA threshold and determines whether the channel is occupied based on the result of the CCA. Meanwhile, if the received frame is determined to be an inter-BSS frame, the terminal accesses the channel based on a second CCA threshold different from the first CCA threshold (second operation). That is, the terminal determines whether the channel is occupied based on both the first CCA threshold and the second CCA threshold. According to an embodiment of the present invention, the second CCA threshold is an overlapping basic service set (OBSS) PD level set to determine whether the channel is occupied depending on the received signal strength of the inter-BSS frame. In this case, the second CCA threshold has a value equal to or greater than the first CCA threshold.

[0094] According to another embodiment, the terminal sets or updates a different NAV depending on whether the received frame is an intra-BSS frame. More specifically, if the received frame is determined to be an intra-BSS frame, the terminal sets or updates a first NAV based on duration information of the corresponding frame (first operation). At this time, the first NAV may be an intra-BSS NAV managed to protect the intra-BSS frame. On the other hand, if the received frame is determined to be an inter-BSS frame, the terminal sets or updates a second NAV based on duration information of the corresponding frame (second operation). At this time, the second NAV may be a basic NAV managed to protect the inter-BSS frame.

[0095] According to an embodiment of the present invention, if a received frame is a VHT PPDU, the non-legacy terminal extracts group ID information and PAID information from the preamble (i.e., VHT-SIG-A) of the corresponding frame. If the extracted group ID information is a preset value (e.g., 63), the non-legacy terminal determines whether the frame is an intra-BSS frame or an inter-BSS frame based on the extracted PAID information. More specifically, the terminal compares the extracted PAID information with information for identifying the terminal's associated BSS to determine whether the frame is an intra-BSS frame or an inter-BSS frame. As will be described later, the information for identifying the terminal's associated BSS includes the terminal's PAID, a BSS color notified by the AP to which the terminal is associated, and a partial BSS color notified by the AP to which the terminal is associated according to an embodiment. Meanwhile, the group ID information of a preset value (i.e., 63) indicates that the corresponding frame is a downlink frame.

[0096] Meanwhile, when AIDs are assigned according to the rule of Equation 2, the corresponding BSS does not use, as an AID value, an AID (8-N+1:8) value that does not follow the rule of Equation 2 among AID candidates of multiple BSSs. According to an embodiment of the present invention, the unused AID value is used to indicate a group of STAs. More specifically, the AID value that does not follow the rule of Equation 2 is implicitly or explicitly designated as an identifier indicating a group of STAs. The identifier indicating a group of STAs is inserted as a STA-ID value in a user field of HE-SIG-B of a High-Efficiency (HE) MU PPDU. The STA of the group indicated by the identifier decodes the corresponding resource unit.

[0097] 9 is a diagram illustrating a non-legacy element format according to an embodiment of the present invention. The AP informs the STA of partial BSS color information using the element illustrated in FIG 9. The non-legacy element is included in a beacon frame, a probe request frame, a probe response frame, an association request frame, an association response frame, a reassociation request frame, a reassociation response frame, etc. Also, the non-legacy element may be transmitted via a frame including the corresponding element alone.

[0098] Referring to FIG. 9, the non-legacy element includes an "Element ID" field, a "Length" field, and a "Partial BSS Color Info" field. The "Element ID" field indicates the type of the element (e.g., "Partial BSS Color Information Element"). The "Length" field indicates the information of the element. The "Partial BSS Color Info" field includes a "Number of Partial BSS Color Bits Used for AID" field, a "Partial BSS Color Bits" field, and a Reserved field. According to one embodiment, the "Partial BSS Color Info" field includes a 3-bit "Number of Partial BSS Color Bits Used for AID" field and a 4-bit "Partial BSS Color Bits" field.

[0099] The "Number of partial BSS color bits used for AID" field indicates the number N of bits of the partial BSS color used for AID allocation. Depending on the value of N, the least significant N-bit(s) of the BSS color are used for AID determination. According to one embodiment, N indicates any one value from 1 to the maximum number of partial BSS color bits (e.g., 4). According to another embodiment, N may additionally indicate 0 to indicate that the partial BSS color is not used for AID allocation. If N indicates 0, the method of determining intra / inter-BSS frames using PAID information of VHT PPDU may not be used. According to one embodiment of the present invention, if the value of the "Number of partial BSS color bits used for AID" field, i.e., N, is set to a value greater than 0, the AP allocates the AID according to the method of Equation 2.

[0100] The 'Partial BSS Color Bits' field indicates a bit value of the partial BSS color. The 'Partial BSS Color Bits' field indicates a BCB value of Equation 2. In addition, the 'Partial BSS Color Bits' field is expressed by the PAID(8-N+1:8) value of Equation 1 when the AID is determined according to an embodiment of the present invention. According to an embodiment, the value of the partial BSS color bits is determined independently of the BSS color. In this way, it is possible to reduce a problem that the partial BSS color value overlaps with that of a neighboring BSS. According to another embodiment, the value of the partial BSS color bits is determined dependently on the BSS color. In this way, a receiver receiving the BSS color information can estimate the value of the partial BSS color bits based on the BSS color information. According to an embodiment of the present invention, the 'Partial BSS Color Bits' field is variably determined depending on the value of the 'Number of Partial BSS Color Bits Used for AID' field.

[0101] According to an embodiment of the present invention, the partial BSS color is set by the AP that operates the corresponding BSS. The AP informs the STAs associated with the BSS of the set partial BSS color. If multiple BSSID sets are used, BSSs of the same multiple BSSID set may use the same partial BSS color.

[0102] According to a further embodiment of the present invention, the AP changes the value of the number of bits N of the partial BSS color used for AID allocation from the corresponding BSS. When the AID is allocated according to the embodiment of Equation 2, the AID (8-N+1:8) has a fixed value in the BSS. Thus, the larger the number of bits N, the fewer the number of AIDs allocated to the STAs. Thus, the AP may reduce the number of bits N to associate with more STAs while allocating AIDs according to the value of the set number of bits N. For example, in order to associate with more STAs, the AP may reduce the value of the number of bits N by 1. In this case, the remaining bits obtained by subtracting the most significant bit or the least significant bit from the partial BSS color bits previously used are used as new partial BSS color bits. In addition, the AP may change the partial BSS color bit value used in the corresponding BSS. In order to change the number of bits N of the partial BSS color used for AID allocation and / or the partial BSS color bit value as described above, the AP transmits the element shown in FIG. 9.

[0103] 10 is a diagram showing a partial AID calculation process according to an embodiment of the present invention. Referring to FIG. 10, in the PAID calculation process according to Equation 1, dec(AID[0:8]) (hereinafter, "specific bit information of AID") in FIG. 10(a) is added to dec(BSSID[44:47] XOR BSSID[40:43])*2^5 (hereinafter, "information obtained from BSSID") in FIG. 10(b). In this case, in the information obtained from BSSID, five bits from B0 to B4 are all set to 0 by the product of 2^5.

[0104] If N is 4 in the AID allocation rule of Equation 2, AID[5:8] is determined to be a fixed value in the BSS according to the rule of Equation 2. Therefore, a single PAID(8-N+1:8) value is determined in the BSS regardless of the assigned AID value and BSSID value. However, if N is smaller than 4 in the AID allocation rule of Equation 2, at least some bits of AID[5:8] are determined to be variable values. Therefore, multiple PAID(8-N+1:8) values ​​are determined in the BSS according to the assigned AID value and BSSID value. For example, if the B(8-N+1-1) value of the information obtained from the BSSID is 1, in the process of adding the specific bit information of the AID and the information obtained from the BSSID, the number of digits may or may not be rounded up according to the B(8-N+1-1) value of the specific bit information of the AID. If such ambiguity is not resolved, an error may occur in which an intra-BSS frame is mistakenly determined to be an inter-BSS frame.

[0105] When determining whether a received frame is an intra-BSS frame or an inter-BSS frame based on the PAID information of the received frame, the terminal checks whether the PAID information extracted from the received frame matches the PAID information related to the BSS to which the terminal is associated. Here, the PAID information refers to a preset bit of PAID. More specifically, the PAID information refers to the upper N-bits of PAID, that is, PAID(8-N+1:8). If the PAID information extracted from the received frame matches the PAID information related to the BSS to which the terminal is associated, the terminal determines that the received frame is an intra-BSS frame. However, if the PAID information extracted from the received frame does not match the PAID information related to the BSS to which the terminal is associated, the terminal determines that the received frame is an inter-BSS frame.

[0106] Meanwhile, in order to solve the problem of ambiguity in determining the PAID value, various PAID comparison methods may be used. According to an embodiment, the terminal compares the PAID (8-N+1:8) extracted from the received frame with all the PAIDs (8-N+1:8) available in the BSS to which the terminal is associated to determine whether the frame is an intra / inter-BSS frame. If the PAID (8-N+1:8) extracted from the received frame matches any one of the PAIDs (8-N+1:8) available in the BSS to which the terminal is associated, the terminal determines the received frame as an intra-BSS frame. However, if the PAID (8-N+1:8) extracted from the received frame does not match any one of the PAIDs (8-N+1:8) available in the BSS to which the terminal is associated, the terminal determines the received frame as an inter-BSS frame. According to an embodiment of the present invention, such a determination of whether the frame is an intra-BSS frame or an inter-BSS frame is performed when the group ID of the received frame is a preset value (e.g., 63).

[0107] According to another embodiment, the terminal performs intra / inter-BSS frame determination by comparing the PAID(8-N+1:8) extracted from the received frame with i) the PAID(8-N+1:8) of the BSS to which the terminal is associated, ii) PAID'(8-N+1:8) obtained by adding 1 to the B(8-N+1) position of the PAID of the BSS to which the terminal is associated, and iii) PAID"(8-N+1:8) obtained by subtracting 1 from the B(8-N+1) position of the PAID of the BSS to which the terminal is associated. If the PAID(8-N+1:8) extracted from the received frame is If the PAID(8-N+1:8) extracted from the received frame matches any one of i), ii), or iii), the terminal determines that the received frame is an intra-BSS frame. However, if the PAID(8-N+1:8) extracted from the received frame does not match any one of i), ii), or iii), the terminal determines that the received frame is an inter-BSS frame. According to an embodiment of the present invention, such a determination of whether a frame is an intra-BSS frame or an inter-BSS frame is made when the group ID of the received frame is a preset value (e.g., 63).

[0108] In order to solve the above-mentioned problem of ambiguity in determining the PAID value, an additional rule is applied when allocating AIDs. According to one embodiment, B(8-N+1-1) of AID is always set to 0. According to another embodiment, if the B(8-N+1-1) value of the information obtained from the BSSID is 0, B(8-N+1-1) of AID is always set to 0.

[0109] Meanwhile, the partial BSS color may be set to the same value even for different BSSs. Therefore, if the determination result of the intra / inter-BSS frame based on the partial BSS color is different from the determination result of the intra / inter-BSS frame based on the MAC address, the determination result based on the MAC address takes precedence over the determination result based on the partial BSS color. For example, if a received frame is determined to be an intra-BSS frame based on the partial BSS color, but the received frame is determined to be an inter-BSS frame based on the MAC address, the terminal determines the received frame to be an inter-BSS frame. Also, according to an embodiment of the present invention, if both the conditions for determining the received frame as an intra-BSS frame and the conditions for determining the received frame as an inter-BSS frame are satisfied, the terminal determines the received frame to be an inter-BSS frame.

[0110] In a specific embodiment, if the received frame is determined to be an intra-BSS frame based on the partial BSS color, but the received frame is determined to be an inter-BSS frame based on the MAC address, the terminal sets or updates the basic NAV as described above. The terminal sets or updates the basic NAV based on duration field information in the MAC header of the received frame.

[0111] FIG. 11 is a diagram showing a detailed calculation process of a partial AID according to an embodiment of the present invention. The AP sets the PAID according to the embodiment of Equation 1, and FIG. 11(a) and FIG. 11(b) show the process. As shown in FIG. 11(b), x indicates bits 0 to 8 of the AID (i.e., AID[0:8]), y indicates (BSSID[44:47] XOR BSSID[40:43])*2^5, z indicates the sum of x and y. Also, FIG. 11(c) shows an allocation rule of AID bits (8-N+1) to bit 8 (i.e., AID[8-N+1:8]) according to Equation 2.

[0112] The process of calculating PAID will be described with reference to FIG. 11(a) to FIG. 11(c). When AID is assigned according to the rule of FIG. 11(c), the upper N-bits of x are assigned according to the rule of FIG. 11(c). According to an embodiment of the present invention, N may be any one of values ​​from 1 to 4. However, according to another embodiment of the present invention, N may be designated as 0, and the AID assignment method according to the rule of FIG. 11(c) and the method of determining intra / inter-BSS frames using PAID may not be performed. N may be transmitted via the non-legacy element described in FIG. 9, but the present invention is not limited thereto. The lower 5-bits of y are all set to 0 (i.e., "00000") by the *2^5 operation of FIG. 11(b). z is calculated by adding x and y, and the PAID is calculated by performing a mod 2^9 operation on z. The mod operation serves to cut off the rounded-up value if a round-up occurs from B8 position to B9 position when z is calculated by the sum of x and y.

[0113] According to an embodiment of the present invention, the upper N-bits of x are determined by a combination of the partial BSS color value and the N-bit value based on the BSSID as in the AID allocation rule shown in FIG. 11(c). Thus, the upper N-bits of x are a BSS-dependent value. Also, y is determined according to the K-bit value based on the BSSID, and is therefore a BSS-dependent value. Thus, the upper N-bits of PAID can be a BSS-dependent value. According to an embodiment of the present invention, the partial BSS color may be used as information for identifying the BSS. The partial BSS color refers to BCB[0:N-1] used in the AID allocation rule of FIG. 11(c). According to one embodiment of the present invention, the partial BSS color is indicated by the upper N-bits of PAID. Meanwhile, according to another embodiment of the present invention, the partial BSS color may refer to the upper N-bits of x.

[0114] Meanwhile, if the ambiguity in determining whether an intra-BSS frame is an inter-BSS frame is not resolved as described above, an error may occur in which an intra-BSS frame is mistakenly determined as an inter-BSS frame. If an intra-BSS frame is mistakenly determined as an inter-BSS frame, the terminal determines whether to occupy the channel based on the second CCA threshold value described above. In this case, the second CCA threshold value is set to a value higher than the first CCA threshold value applied to the intra-BSS frame. If the terminal performs channel access based on the second CCA threshold value, interference may occur with the received packet. In addition, since the AP is transmitting a corresponding packet, the AP cannot receive the packet transmitted by the terminal. In this way, the intra / inter-BSS frame determination error of the terminal may hinder the operation of the intra-BSS.

[0115] Therefore, a method for resolving the ambiguity of determining whether an intra-BSS frame is an inter-BSS frame is required. Hereinafter, a method for determining whether an intra-BSS frame is an inter-BSS frame according to various embodiments of the present invention will be described with reference to the drawings. In each embodiment, it is assumed that the received frame is a VHT PPDU with a group ID set to 63 (i.e., a downlink frame).

[0116] FIG. 12 is a diagram illustrating a method of determining whether a frame is an intra-BSS frame or an inter-BSS frame according to a first embodiment of the present invention. According to one embodiment of the present invention, a plurality of PAID (8-N+1:8) values ​​are determined within a BSS according to an assigned AID value and a BSSID value. Thus, the terminal compares the PAID (8-N+1:8) extracted from the received frame with all possible PAIDs (8-N+1:8) in the BSS to which the terminal is associated to determine whether the frame is an intra / inter-BSS frame. If the PAID (8-N+1:8) extracted from the received frame matches any one of all possible PAIDs (8-N+1:8) in the BSS to which the terminal is associated, the terminal determines that the received frame is an intra-BSS frame. However, if the PAID (8-N+1:8) extracted from the received frame does not match any one of all possible PAIDs (8-N+1:8) in the BSS to which the terminal is associated, the terminal determines that the received frame is an inter-BSS frame.

[0117] Figures 12(a) and 12(b) show a method for determining whether a received frame is an intra-BSS frame or an inter-BSS frame based on the PAID calculation process of the receiving terminal. Figure 12(a) shows a determination method in the case where rounding up of the number of digits occurs in B(8-N+1-1) in the PAID calculation process of the terminal described in Figures 10 and 11. Figure 12(b) shows a determination method in the case where rounding up of the number of digits does not occur in B(8-N+1-1) in the PAID calculation process of the terminal described in Figures 10 and 11.

[0118] First, referring to FIG. 12(a), the terminal receives a wireless frame and extracts PAID information from the received frame (S1210). At this time, the group ID is also extracted from the received frame, and it is assumed that the group ID is 63. The terminal determines whether the PAID (8-N+1:8) of the received frame matches any one of the following (S1220): ai) terminal's PAID (8-N+1:8), a-ii) terminal's PAID (8-N+1:8)-1 (8-N+1). Here, 1 (8-N+1) refers to 1 in bit (8-N+1) of PAID. In the embodiment of FIG. 12(a), since rounding up of the number of digits occurs during the terminal's PAID calculation process, PAID' (8-N+1:8) obtained by subtracting 1 from the terminal's PAID (8-N+1:8) may exist in the BSS. Therefore, the terminal determines whether the PAID(8-N+1:8) of the received frame matches any one of ai) and a-ii) above. If the PAID(8-N+1:8) extracted from the received frame matches any one of ai) and a-ii), the terminal determines the received frame to be an intra-BSS frame (S1230). However, if the PAID(8-N+1:8) extracted from the received frame does not match any of ai) and a-ii), the terminal determines the received frame to be an inter-BSS frame (S1232).

[0119] Next, referring to FIG. 12(b), the terminal receives a wireless frame and extracts PAID information from the received frame (S1260). At this time, the group ID is also extracted from the received frame, and it is assumed that the group ID is 63. The terminal determines whether the PAID (8-N+1:8) of the received frame matches any one of the following (S1270): bi) terminal's PAID (8-N+1:8), b-ii) terminal's PAID (8-N+1:8) + 1 (8-N+1). Here, 1 (8-N+1) refers to 1 in bit (8-N+1) of PAID. In the embodiment of FIG. 12(b), since no rounding up occurs during the terminal's PAID calculation process, PAID"(8-N+1:8), which is the terminal's PAID(8-N+1:8) plus 1, may exist in the BSS. Therefore, the terminal determines whether the PAID(8-N+1:8) of the received frame matches any one of bi) or b-ii). If the PAID(8-N+1:8) extracted from the received frame matches any one of bi) or b-ii), the terminal determines the received frame to be an intra-BSS frame (S1280). However, if the PAID(8-N+1:8) extracted from the received frame does not match any of bi) or b-ii), the terminal determines the received frame to be an inter-BSS frame (S1282).

[0120] 13 is a diagram illustrating a method for determining whether an intra-BSS frame or an inter-BSS frame is a frame according to a second embodiment of the present invention. According to the second embodiment of the present invention, a terminal calculates a reference value X' for determining whether an intra / inter-BSS frame is a frame using a PAID value of a received frame and a K-bit value based on the BSSID of a BSS to which the terminal is associated.

[0121] More specifically, the terminal receives a wireless communication frame and extracts PAID information from the received frame (S1310). At this time, a group ID is also extracted from the received frame, and it is assumed that the group ID is 63. The terminal calculates a reference value X' by using the PAID value of the received frame and a K-bit value based on the BSSID of the BSS to which the terminal is associated (S1320). In an embodiment of the present invention, the reference value X' is determined by a combination of the PAID value of the received frame and the K-bit value based on the BSSID of the BSS to which the terminal is associated. More specifically, the reference value X' is calculated by subtracting the product of the K-bit value based on the BSSID of the BSS to which the terminal is associated and 2^5 (i.e., y') from the PAID value of the received frame (i.e., (x+y) mod 2^9 in FIG. 11). A detailed embodiment thereof will be described later with reference to FIG. 14. The terminal determines whether the reference value X'(8-N+1:8) matches the terminal's AID(8-N+1:8) (S1330). If the reference value X'(8-N+1:8) matches the terminal's AID(8-N+1:8), the terminal determines the received frame to be an intra-BSS frame (S1340). However, if the reference value X'(8-N+1:8) does not match the terminal's AID(8-N+1:8), the terminal determines the received frame to be an inter-BSS frame (S1342).

[0122] 14 is a diagram illustrating a process of calculating a reference value for determining an intra / inter-BSS frame and a process of calculating a partial AID according to an embodiment of the present invention. In the embodiment of FIG. 14, the definitions of each variable are as follows.

[0123] - PAID indicates the partial AID extracted from the received frame. The PAID is extracted from the VHT-SIG-A1 of the received VHT PPDU.

[0124] -x indicates the AID (0:8) of the intended recipient of the frame.

[0125] -y indicates (BSSID[44:47] XOR BSSID[40:43])*2^5 of the BSS to which the terminal that sent the frame belongs.

[0126] -y' indicates (BSSID[44:47] XOR BSSID[40:43])*2^5 of the BSS to which the terminal receiving the frame is bound.

[0127] In other words, y represents a product of 2^5 and a K-bit value based on the BSSID of the BSS to which the terminal that transmitted the frame is associated, and y' represents a product of 2^5 and a K-bit value based on the BSSID of the BSS to which the terminal that received the frame is associated. In the embodiment of FIG. 14, x' represents a 9-bit binary value. A separate bin[x',9] operation is performed to obtain the binary x' from the value calculated according to the embodiment of FIG. 14(a).

[0128] First, Figure 14(a) shows a process of calculating a reference value X' for determining whether it is an intra / inter-BSS frame. A terminal receiving a frame compares the PAID extracted from the received frame with y'. If PAID-y' is less than 0 (i.e., Case RX1), the terminal sets x' to PAID-y'+2^9. However, if PAID-y' is greater than or equal to 0 (i.e., Case RX2), the terminal sets X' to PAID-y'. The terminal uses the reference value x' calculated in this way to determine whether it is an intra / inter-BSS frame as in the embodiment of Figure 13.

[0129] Next, Fig. 14(b) shows a process in which a terminal transmitting a PPDU calculates a PAID. Referring to the embodiment of Fig. 11, the PAID is calculated as (x+y) mod 2^9. Here, x and y are 9-bit values, so x and y respectively satisfy the following conditions. 0≦x<2^9, 0≦y<2^9

[0130] Therefore, x+y satisfies the following condition. 0≦x+y<2^10

[0131] Thus, according to an embodiment of the present invention, PAID is calculated as follows: if x+y is greater than or equal to 2^9 (i.e., Case TX1), then PAID is set to x+y-2^9; but if x+y is less than 2^9 (i.e., Case TX2), then PAID is set to x+y.

[0132] When the reference value x' is used according to an embodiment of the present invention, the process of determining whether the receiving terminal is an intra / inter-BSS frame is as follows: First, if the frame received by the terminal is an intra-BSS frame, the receiving terminal makes the following determination: If the terminal receives an intra-BSS frame, y and y' are all determined based on the same BSSID, so y=y' is satisfied.

[0133] A-1) When the transmitting terminal calculates PAID according to Case Tx1 According to the formula for Case Tx1, PAID-y=x-2^9 is satisfied. In this case, since x is smaller than 2^9, PAID-y<0 is satisfied. Since the values ​​of y and y' are the same, PAID-y'<0 is satisfied, and the receiving terminal calculates x' according to Case Rx1. In this case, x' satisfies the following formula.

[0134]

number

[0135] That is, x' = x, and x'(8-N+1:8) = x(8-N+1:8). If the AID of each terminal is assigned according to the above rule, terminals in the same BSS will have the same AID(8-N+1:8) value. Therefore, X'(8-N+1:8) matches the AID(8-N+1:8) of the receiving terminal, and the receiving terminal determines that the frame is an intra-BSS frame.

[0136] A-2) When the transmitting terminal calculates PAID according to Case Tx2 According to the formula of Case Tx2, PAID-y = x is satisfied. In this case, x is greater than or equal to 0, so PAID-y ≥ 0. Since the values ​​of y and y' are the same, PAID-y' ≥ 0 is satisfied, and the receiving terminal calculates x' according to Case Rx2. In this case, x' satisfies the following formula:

[0137]

number

[0138] That is, x' = x, and x'(8-N+1:8) = x(8-N+1:8). If the AID of each terminal is assigned according to the above rule, terminals in the same BSS will have the same AID(8-N+1:8) value. Therefore, X'(8-N+1:8) matches the AID(8-N+1:8) of the receiving terminal, and the receiving terminal determines that the frame is an intra-BSS frame.

[0139] Next, if the frame received by the terminal is an inter-BSS frame, the receiving terminal makes the following judgment: When the terminal receives an inter-BSS frame, y and y' are determined based on different BSSIDs, so there is a high probability that y and y' represent different values.

[0140] B-1) When the transmitting terminal calculates PAID according to Case Tx1 and the receiving terminal calculates x' according to Case RX1 In this case, x' satisfies the following formula.

[0141]

number

[0142] Therefore, if y and y’ are different, then x’ and x are different. Since the lower 5 bits of y and y’ are all 0, x’(5:8) and x(5:8) are different from each other. If N is set to a value of 4 or less, x’(8-N+1:8) refers to at least some of the bits of x’(5:8), and x(8-N+1:8) refers to at least some of the bits of x(5:8). Therefore, there is a high probability that X’(8-N+1:8) and x(8-N+1:8) are different from each other. As a result, there is a high probability that x’(8-N+1:8) is different from the AID(8-N+1:8) of the receiving terminal. Thereby, the receiving terminal has a high probability of determining that the corresponding frame is an inter-BSS frame.

[0143] B-2) When the transmitting terminal calculates the PAID by Case Tx2 and the receiving terminal calculates x’ by Case RX1 At this time, x’ comes to satisfy the following mathematical formula.

[0144]

Equation

[0145] At this time, in order to satisfy -2^9 < y - y’ < 2^9, if y and y’ are different, then x’ and x are different. As described above, if x’ and x are different, there is a high probability that X’(8-N+1:8) and x(8-N+1:8) are different from each other. As a result, there is a high probability that X’(8-N+1:8) is different from the AID(8-N+1:8) of the receiving terminal. Thereby, the receiving terminal has a high probability of determining that the corresponding frame is an inter-BSS frame.

[0146] B-3) When the transmitting terminal calculates the PAID by Case Tx1 and the receiving terminal calculates x’ by Case RX2 At this time, x’ comes to satisfy the following mathematical formula.

[0147]

Equation

[0148] At this time, in order to satisfy -2^9 < y - y' < 2^9, if y and y' are different, then x' and x are different. As described above, if x' and x are different, the probability that x'(8 - N + 1:8) and x(8 - N + 1:8) are different from each other is high. As a result, the probability that x'(8 - N + 1:8) is different from the AID(8 - N + 1:8) of the receiving terminal is high. Thereby, the receiving terminal has a high probability of determining that the corresponding frame is an inter - BSS frame.

[0149] B - 4) When the transmitting terminal calculates the PAID by Case Tx2 and the receiving terminal calculates x' by Case RX2 At this time, x' satisfies the following formula.

[0150]

Equation

[0151] If y and y' are different, then x' and x are different. As described above, if x' and x are different, the probability that x'(8 - N + 1:8) and x(8 - N + 1:8) are different from each other is high. As a result, the probability that x'(8 - N + 1:8) is different from the AID(8 - N + 1:8) of the receiving terminal is high. Thereby, the receiving terminal has a high probability of determining that the corresponding frame is an inter - BSS frame.

[0152] On the other hand, the determination method of comparing the PAID(8 - N + 1:8) of the received frame with the PAID(8 - N + 1:8) of the terminal has both the possibility of misjudging an inter - BSS frame as an intra - BSS frame and the possibility of misjudging an intra - BSS frame as an inter - BSS frame. However, the determination method according to the embodiment of FIG. 13 has the possibility of misjudging an inter - BSS frame as an intra - BSS frame, but the possibility of misjudging an intra - BSS frame as an inter - BSS frame is eliminated.

[0153] According to a further embodiment of the present invention, the terminal compares the value calculated using x'(8-N+1:8) and y'(8-N+1:8) with the partial BSS color value (i.e., BCB information) to determine whether the frame is intra / inter-BSS. More specifically, if the value of x'(8-N+1:8)-y'(8-N+1:8) is less than 0, the terminal determines whether the value of x'(8-N+1:8)-y'(8-N+1:8)+2^N matches the partial BSS color value known to the terminal. If they match, the terminal determines the received frame as an intra-BSS frame, and if they do not match, the terminal determines the received frame as an inter-BSS frame. On the other hand, if the value of x'(8-N+1:8)-y'(8-N+1:8) is greater than or equal to 0, the terminal determines whether the value of x'(8-N+1:8)-y'(8-N+1:8) matches the partial BSS color value known to the terminal. If there is a match, the terminal determines that the received frame is an intra-BSS frame, and if there is no match, the terminal determines that the received frame is an inter-BSS frame.

[0154] The determination method according to the embodiment of Figures 12 to 14 described above is performed if the terminal determines that there is ambiguity in the PAID value determination. In one embodiment, if the terminal determines that there is no ambiguity in the PAID determination, the terminal compares the PAID (8-N+1:8) of the received frame with the terminal's PAID (8-N+1:8) to determine whether the frame is an intra / inter-BSS frame. That is, if the PAID (8-N+1:8) extracted from the received frame matches the terminal's PAID (8-N+1:8), the terminal determines the received frame as an intra-BSS frame. However, if the PAID (8-N+1:8) extracted from the received frame does not match the terminal's PAID (8-N+1:8), the terminal determines the received frame as an inter-BSS frame.

[0155] Whether or not there is ambiguity in determining a PAID value is recognized by the terminal according to various embodiments. According to one embodiment, if y(5:8-N+1-1) is all 0, the terminal determines that there is ambiguity, otherwise, it determines that there is no ambiguity. According to another embodiment, if N=4 is set, the terminal determines that there is no ambiguity, and if N is any one value from 1 to 3, the terminal determines that there is ambiguity. Here, N indicates the number of bits of partial BSS color and the number of bits of BSSID information used in AID allocation. According to another embodiment, the terminal recognizes whether or not there is ambiguity in determining a PAID value in the method described in FIG. 15 and FIG. 16.

[0156] 15 is a diagram showing a non-legacy element format according to another embodiment of the present invention. Among the fields of the non-legacy element in FIG 15, duplicated descriptions will be omitted for the same parts as the fields of the non-legacy element described in FIG 9.

[0157] 15, the non-legacy element includes an "element ID" field, a "length" field, and a "partial BSS color information" field. The "partial BSS color information" field also includes a "number of partial BSS color bits used for AID" field, a "partial BSS color bits" field, and an "ambiguity" field. According to one embodiment, the "partial BSS color information" field includes a 3-bit "number of partial BSS color bits used for AID" field, a 4-bit "partial BSS color bits" field, and a 1-bit "ambiguity" field. The "ambiguity" field signals whether there may be ambiguity in determining the PAID value via a flag value.

[0158] FIG. 16 is a diagram illustrating a method of signaling partial BSS color bit number information and ambiguity information according to another embodiment of the present invention. According to the embodiment of the present invention, the "number of partial BSS color bits used for AID" field of the non-legacy element signals whether the above-mentioned ambiguity may exist. More specifically, the "number of partial BSS color bits used for AID" field indicates both the number of partial BSS color bits used for AID allocation and whether the ambiguity may exist through a preset index. For example, indexes 1 to 4 indicate that the number of partial BSS color bits used for AID allocation is 1 to 4, respectively, and the ambiguity does not exist. On the other hand, if the number of partial BSS color bits used for AID allocation is 4, there is no ambiguity in determining the PAID value. Thus, indexes 5 to 7 additionally indicate that the number of partial BSS color bits used for AID allocation is 1 to 3, respectively, and the ambiguity may exist.

[0159] 17A and 17B are diagrams showing AID allocation information and a non-legacy element format according to a second embodiment of the present invention, in which (a) shows an AID allocation method according to another embodiment of the present invention, and (b) shows the corresponding non-legacy element format.

[0160] First, referring to FIG. 17(a), the AID allocation method according to the second embodiment of the present invention can be expressed as Equation 9 below.

[0161]

number

[0162] Here, N is 4.

[0163] The AID allocation method according to the second embodiment of the present invention is the same as the AID allocation method according to the first embodiment described through Equation 2, but N is limited to 4. More specifically, the preset N-bits of the AID are determined using the value of the least significant N-bit(s) of the BSS color (i.e., the partial BSS color value) and the N-bit value based on the BSSID. That is, the preset N-bits of the AID are determined by performing a modulo operation on the sum of the value of the least significant N-bit(s) of the partial BSS color and the N-bit value based on the BSSID. In this case, the preset N-bit(s) of the AID are the bits from bit 8-N+1 to bit 8 of the AID, and N is set to 4. According to the above-mentioned PAID configuration rule of FIG. 1, the number of effective bits K of the BSSID-based value used for PAID configuration is set to 4. According to the embodiment of the present invention, in the AID allocation rule, N is set to 4, which is the same value as K used when configuring the PAID, thereby eliminating ambiguity in determining the PAID value.

[0164] Referring to FIG. 17(b), the 'Partial BSS Color Information' field of the non-legacy element includes a 1-bit 'Partial BSS Color Bit Indication' field and a 4-bit 'Partial BSS Color Bit' field. The 'Partial BSS Color Bit Indication' field indicates whether the corresponding BSS applies an AID allocation rule using partial BSS color bits. If the field is set to 1, an N-bit (here, N is 4) partial BSS color value is used for AID allocation. However, if the field is set to 0, the partial BSS color is not used for AID allocation. According to the embodiment of FIG. 17, the number of bits N of the partial BSS color used for AID allocation is fixed. Therefore, the non-legacy element indicates whether the partial BSS color is used for AID allocation via the 1-bit 'Partial BSS Color Bit Indication' field.

[0165] According to another embodiment of the present invention, the 'Partial BSS Color Information' field of the non-legacy element may include only the 'Partial BSS Color Bits' field without a separate 'Partial BSS Color Bit Indication' field. When the 'Partial BSS Color Bits' field information is signaled through the 'Partial BSS Color Information' field, the terminal receiving the corresponding non-legacy element recognizes that the partial BSS color value is used for AID allocation.

[0166] 18 is a diagram illustrating an AID allocation method according to a third embodiment of the present invention, which can be expressed as Equation 10 below.

[0167]

number

[0168] Here, N is an integer between 1 and 4.

[0169] According to a third embodiment of the present invention, the bit(s) from bit 8-N+1 to bit 8 of the AID are set according to the rule of Equation 10. According to the embodiment of Equation 10, the preset N-bit(s) of the AID are determined based on a value obtained by subtracting BSSID information from BSB information. In this case, the preset N-bit(s) of the AID are the bit(s) from bit 8-N+1 to bit 8 of the AID. More specifically, the preset N-bit(s) of the AID are determined by subtracting the BSSID-based N-bit value from the value of the least significant N-bit(s) of the BSS color (i.e., the partial BSS color value). The BSSID-based N-bit value indicates an exclusive OR of the first preset N-bit(s) of the BSSID and the second preset N-bit(s) of the BSSID. In the embodiment of Equation 10, the first preset N-bit(s) refers to the bit(s) from bit 47-N+1 to bit 47, and the second preset N-bit(s) refers to the bit(s) from bit 43-N+1 to bit 43.

[0170] If the partial BSS color value minus the BSSID-based N-bit value is less than 0, the preset N-bit(s) of the AID is determined by adding 2^N to the partial BSS color value minus the BSSID-based N-bit value. However, if the partial BSS color value minus the BSSID-based N-bit value is greater than or equal to 0, the preset N-bit(s) of the AID is determined by the partial BSS color value minus the BSSID-based N-bit value.

[0171] When the AID is assigned according to the rule of Equation 10, the preset N-bit(s) of the AID and the corresponding upper N-bit(s) of the PAID have BSS discrimination power. Therefore, if the received frame is a VHT PPDU (and the group ID extracted from the received frame is 63), the terminal compares the upper N-bit(s) of the PAID extracted from the received frame with the partial BSS color known to the terminal to determine whether the frame is an intra-BSS frame or an inter-BSS frame. If the upper N-bit(s) of the PAID match the partial BSS color known to the terminal, the terminal determines the received frame as an intra-BSS frame. However, if the upper N-bit(s) of the PAID do not match the partial BSS color known to the terminal, the terminal determines the received frame as an inter-BSS frame.

[0172] 19 is a diagram illustrating an AID allocation method according to a fourth embodiment of the present invention. Referring to FIG 18, the AID allocation method according to the fourth embodiment of the present invention can be expressed as in Equation 11 below.

[0173]

number

[0174] Here, N is an integer between 1 and 4.

[0175] According to the fourth embodiment of the present invention, the bit(s) from bit 5 to bit 5+N-1 of the AID are set according to the rule of Equation 11. According to the embodiment of Equation 11, the preset N-bit(s) of the AID are determined by performing a modulo operation on the sum of the value of the least significant N-bit(s) of the BSS color (i.e., the partial BSS color value) and the N-bit value based on the BSSID. In this case, the preset N-bit(s) of the AID are the bit(s) from bit 5 to bit 5+N-1 of the AID. The N-bit value based on the BSSID indicates the exclusive OR of the first preset N-bit(s) of the BSSID and the second preset N-bit(s) of the BSSID. In the embodiment of Equation 11, the first preset N-bit(s) refers to the bit(s) from bit 44 to bit 44+N-1, and the second preset N-bit(s) refers to the bit(s) from bit 40 to bit 40+N-1.

[0176] As described above in FIG. 11, in the PAID calculation process, the lower 5 bits of y are all set to 0 (i.e., "00000"). In this case, when the bits from bit 5 to bit 5+N-1 of AID are set according to the rule of Equation 11, PAID(5:5+N-1) has a fixed value within the BSS. Therefore, when AID is assigned according to the rule of Equation 11, ambiguity in determining the PAID value is prevented. In addition, the pre-set bits of PAID, i.e., PAID(5:5+N-1), have BSS discrimination power. Therefore, if the received frame is a VHT PPDU (and the group ID extracted from the received frame is 63), the terminal compares the PAID(5:5+N-1) of the PAID extracted from the received frame with the PAID(5:5+N-1) of the BSS to which the terminal is associated to determine whether the frame is an intra-BSS frame or an inter-BSS frame. If the PAID(5:5+N-1) of the received frame matches the PAID(5:5+N-1) of the BSS to which the terminal is associated, the terminal determines the received frame as an intra-BSS frame. However, if the PAID(5:5+N-1) of the received frame does not match the PAID(5:5+N-1) of the BSS to which the terminal is associated, the terminal determines the received frame as an inter-BSS frame.

[0177] 20 and 21 are diagrams illustrating an AID allocation method according to a fifth embodiment of the present invention. First, referring to FIG. 20, the AID allocation method according to the fifth embodiment of the present invention can be expressed as in Equation 12 below.

[0178]

number

[0179] Here, N is an integer between 1 and 4.

[0180] According to the fifth embodiment of the present invention, the bit(s) from bit 5 to bit 5+N-1 of the AID are set according to the rule of Equation 12. According to the embodiment of Equation 12, the preset N-bit(s) of the AID are determined based on a value obtained by subtracting BSSID information from BCB information. More specifically, the preset N-bit(s) of the AID are determined by performing a modulo operation on a value obtained by subtracting the BSSID-based N-bit value from the value of the least significant N-bit(s) of the BSS color (i.e., the partial BSS color value). In this case, the preset N-bit(s) of the AID are the bit(s) from bit 5 to bit 5+N-1 of the AID. The BSSID-based N-bit value represents an exclusive OR of the first preset N-bit(s) of the BSSID and the second preset N-bit(s) of the BSSID. In the embodiment of Equation 12, the first preset N-bit(s) refers to the bit(s) from bit 44 to bit 44+N-1, and the second preset N-bit(s) refers to the bit(s) from bit 40 to bit 40+N-1.

[0181] The AID allocation method according to the fifth embodiment of the present invention is shown in FIG.

[0182]

number

[0183] Here, N is an integer between 1 and 4.

[0184] Referring to Equation 13, if the value obtained by subtracting the BSSID-based N-bit value from the partial BSS color value is less than 0, the preset N-bit(s) of the AID is determined by adding 2^N to the value obtained by subtracting the BSSID-based N-bit value from the partial BSS color value. However, if the value obtained by subtracting the BSSID-based N-bit value from the partial BSS color value is greater than or equal to 0, the preset N-bit(s) of the AID is determined by the value obtained by subtracting the BSSID-based N-bit value from the partial BSS color value.

[0185] As described above in FIG. 11, in the PAID calculation process, the lowest 5 bits of y are all set to 0 (i.e., "00000"). In this case, when the bits from bit 5 to bit 5+N-1 of AID are set according to the rules of Equation 12 and Equation 13, PAID[5:5+N-1] has a fixed value within the BSS. Therefore, when AID is assigned according to the rules of Equation 12 and Equation 13, ambiguity in determining the PAID value is prevented.

[0186] Also, if the AID is assigned according to the rules of Equation 12 and Equation 13, at least a portion of the K-bit value based on the BSSID (i.e., y in FIG. 11) is offset with the N-bit value based on the BSSID when setting the PAID according to the embodiment of Equation 1. Thus, the pre-configured bits of the PAID (i.e., PAID[5:5+N-1]) indicate the partial BSS color value known to the intended recipient of the corresponding frame. Thus, if the received frame is a VHT PPDU (and the group ID extracted from the received frame is 63), the terminal compares the pre-configured bits of the PAID extracted from the received frame with the partial BSS color known to the terminal to determine whether the frame is an intra-BSS frame or an inter-BSS frame. If the PAID pre-configured bits match the partial BSS color known to the terminal, the terminal determines the received frame as an intra-BSS frame. However, if the PAID pre-configured bits do not match the partial BSS color known to the terminal, the terminal determines the received frame as an inter-BSS frame.

[0187] Hereinafter, the reason why the preset bits of PAID (i.e., PAID[5:5+N-1]) indicate partial BSS color values ​​when the AID allocation method according to the fifth embodiment of the present invention is used will be described in more detail. If the received frame is a downlink SU frame in VHT PPUD, the PAID extracted from the corresponding frame is determined according to the above-mentioned Equation 1. In this case, when AID[0:8] is divided into the lowest 5-bits (i.e., AID[0:4]), the next 5-bits(s) (i.e., AID[5:5+N-1]), and the remaining bits(s) (i.e., AID[5+N:8]), it is expressed as Equation 14.

[0188]

number

[0189] (Case a) dec(BCB[0:N-1]-dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]))<0 Since 0≦dec(BCB[0:N-1])<2^N and 0≦dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]))<2^N, AID[5:5+N-1] is determined according to the if condition in Equation 13 as follows:

[0190]

number

[0191] (Case a-1) When N is not 4 Substituting Equation 15 into Equation 14 gives the following equation:

[0192]

number

[0193] Here, the part of the value based on the BSSID, i.e., dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]), is offset and rearranged as shown in the following formula:

[0194]

number

[0195] Referring to Equation 17, the only factor affecting PAID[5:5+N-1] is dec(BCB[0:N-1])*2^5. Therefore, PAID[5:5+N-1] has the same value as BCB[0:N-1].

[0196] (Case a-2) When N is 4 If N is 4, dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]) in Equation 15 is the same as dec(BSSID[44:47] XOR BSSID[40:43]) in Equation 14. Therefore, substituting Equation 15 into Equation 14 gives the following equation.

[0197]

number

[0198] Referring to Equation 18, the only factor affecting PAID[5:5+N-1] is dec(BCB[0:N-1])*2^5. Therefore, PAID[5:5+N-1] has the same value as BCB[0:N-1].

[0199] (Case b) dec(BCB[0:N-1]-dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1])) ≥ 0 Since 0≦dec(BCB[0:N-1])<2^N and 0≦dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]))<2^N, AID[5:5+N-1] is determined according to the else condition in Equation 13 as follows:

[0200]

number

[0201] (Case b-1) When N is not 4 Substituting Equation 19 into Equation 14 gives the following equation:

[0202]

number

[0203] Here, the part of the value based on the BSSID, i.e., dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]), is offset and rearranged as shown in the following formula:

[0204]

number

[0205] Referring to Equation 21, the only factor affecting PAID[5:5+N-1] is dec(BCB[0:N-1])*2^5. Therefore, PAID[5:5+N-1] has the same value as BCB[0:N-1].

[0206] (Case a-2) When N is 4 If N is 4, dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]) in Equation 19 is the same as dec(BSSID[44:47] XOR BSSID[40:43]) in Equation 14. Therefore, substituting Equation 19 into Equation 14 gives the following equation.

[0207]

number

[0208] Referring to Equation 22, the only factor affecting PAID[5:5+N-1] is dec(BCB[0:N-1])*2^5. Therefore, PAID[5:5+N-1] has the same value as BCB[0:N-1].

[0209] Thus, in all cases, the set bits of PAID, i.e., PAID[5:5+N-1], will have the same value as the fractional BSS color value, i.e., BCB[0:N-1].

[0210] 22 is a diagram illustrating a method for determining whether an intra-BSS frame or an inter-BSS frame is present according to a third embodiment of the present invention. The method for determining whether an intra-BSS frame or an inter-BSS frame is present shown in FIG. 22 is used when an AID is assigned according to the fifth embodiment described with reference to FIG. 20 and FIG. 21.

[0211] First, the terminal receives a wireless frame and extracts group ID and PAID information from the received frame (S2210). If the received frame is a VHT PPDU, the RXVECTOR parameter of the corresponding frame includes group ID and PAID. Therefore, if the received frame is a VHT PPDU, the terminal extracts group ID and PAID information from the preamble of the VHT PPDU.

[0212] Next, the terminal checks what information the extracted group ID indicates (S2220). More specifically, the terminal checks whether the extracted group ID information is 0 or 63. As described above in the embodiment of FIG. 8, group ID 0 indicates that the corresponding frame is an upstream frame. Also, group ID 63 indicates that the corresponding frame is a downstream frame. That is, the terminal identifies whether the corresponding frame is an upstream frame or a downstream frame through the extracted group ID information.

[0213] If the extracted group ID information is 0 (i.e., an uplink frame is indicated), the terminal checks whether the PAID extracted from the frame matches a specific bit value of the BSSID of the BSS to which the terminal is associated (S2230). In this case, the specific bit value of the BSSID is BSSID[39:47]. As described above in FIG. 8, if it is an uplink frame, the PAID is set to BSSID[39:47], so the terminal determines whether the corresponding frame is an intra-BSS frame or an inter-BSS frame depending on whether the PAID of the received frame matches the BSSID[38:47] of the BSS to which the terminal is associated. If the PAID matches the BSSID[39:47], the terminal determines the received frame as an intra-BSS frame (S2232). However, if the PAID does not match the BSSID[39:47], the terminal determines the received frame as an inter-BSS frame (S2234).

[0214] On the other hand, if the extracted group ID information is 63 (i.e., indicates a downlink frame), the terminal checks whether the PAID extracted from the frame matches the partial BSS color known to the terminal (S2240). At this time, the PAID information refers to the preset bit(s) of PAID. In the embodiment of FIG. 22, the preset bit(s) of PAID refers to PAID[5:5+N-1]. Also, the partial BSS color known to the terminal refers to the partial BSS color known by the AP to which the terminal is associated. When the AID is assigned according to the fifth embodiment of the present invention, if the PAID is set, at least a part of the K-bit value based on the BSSID is offset with the N-bit value based on the BSSID. Thus, the preset bit of the PAID (i.e., PAID[5:5+N-1]) indicates the partial BSS color known to the intended recipient of the frame. Thus, the terminal determines whether the corresponding frame is an intra-BSS frame or an inter-BSS frame depending on whether the preset bit of the PAID of the received frame matches the partial BSS color known to the terminal. If the PAID preset bits match the partial BSS color known to the terminal, the terminal determines the received frame as an intra-BSS frame (S2242). However, if the PAID preset bits do not match the partial BSS color known to the terminal, the terminal determines the received frame as an inter-BSS frame (S2244).

[0215] According to one embodiment of the present invention, when the extracted group ID information is 63, the method of determining whether an intra-BSS frame or an inter-BSS frame is performed only if the value N of the "Number of partial BSS color bits used for AID" field of the non-legacy element most recently received from the associated AP is not 0. According to another embodiment of the present invention, when the extracted group ID information is 63, the method of determining whether an intra-BSS frame or an inter-BSS frame is performed only if the "Partial BSS color bit indication" field of the non-legacy element most recently received from the associated AP is set to 1. As described above, when the "Partial BSS color bit indication" field is set to 1, the AID allocation rule using the partial BSS color bit is applied.

[0216] 23 is a diagram showing a non-legacy element format according to another embodiment of the present invention. Among the fields of the non-legacy element in FIG. 23, duplicated descriptions will be omitted for the same parts as the fields of the non-legacy element described in the above embodiment.

[0217] The operation of an HE STA (i.e., a non-legacy terminal) in an HE BSS is controlled by an HT operation element, a VHT operation element, an HE operation element (i.e., a non-legacy element), etc. As described above, the non-legacy elements are included in a beacon frame, a probe request frame, a probe response frame, an association request frame, an association response frame, a reassociation request frame, a reassociation response frame, etc. Also, the non-legacy elements may be transmitted via a frame that includes the corresponding element alone. Referring to FIG. 23, the non-legacy elements include an 'element ID' field, a 'length' field, and an 'HE operation parameters' field. Also, the 'HE operation parameters' field includes a 'BSS color' field and a 'partial BSS color length' field.

[0218] The 'BSS Color' field indicates a BSS color value. The BSS Color indicates the BSS Color of the BSS operated by the AP transmitting the corresponding element. The BSS Color may also indicate the BSS Color of the BSS to which the STA transmitting the corresponding element is associated. The 'BSS Color' field has a length of 6-bits and indicates an unsigned integer value. According to an embodiment, if the value of the 'BSS Color' field is not 0, it indicates the BSS Color, and if the value of the 'BSS Color' field is 0, it indicates that the BSS Color is not set for the corresponding BSS.

[0219] The "Partial BSS Color Length" field includes information regarding intra / inter-BSS frame determination using the PAID of the VHT PPDU. For example, the "Partial BSS Color Length" field indicates the number of bits N of the partial BSS color used for AID allocation. The "Partial BSS Color Length" field performs the same function as the "Number of Partial BSS Color Bits Used for AID" field described above. The "Partial BSS Color Length" field has a length of 3 bits, but the present invention is not limited thereto.

[0220] 24 is a diagram illustrating an AID allocation method according to a sixth embodiment of the present invention. First, referring to FIG 24, the AID allocation method according to the sixth embodiment of the present invention can be expressed as in Equation 23 below.

[0221]

number

[0222] Here, N is 4.

[0223] According to the sixth embodiment of the present invention, the bit(s) from bit 8-N+1 to bit 8 of the AID are set according to the rule of Equation 23. According to the embodiment of Equation 23, the preset N-bit(s) of the AID are determined based on a value obtained by subtracting BSSID information from BSB information. More specifically, the preset N-bit(s) of the AID are determined by performing a modulo operation on a value obtained by subtracting the BSSID-based N-bit value from the value of the least significant N-bit(s) of the BSS color (i.e., the partial BSS color value). In this case, the preset N-bit(s) of the AID are the bit(s) from bit 8-N+1 to bit 8 of the AID. The BSSID-based N-bit value represents an exclusive OR of the first preset N-bit(s) of the BSSID and the second preset N-bit(s) of the BSSID. In the embodiment of Equation 23, the first preset N-bit(s) refers to the bit(s) from bit 47-N+1 to bit 47, and the second preset N-bit(s) refers to the bit(s) from bit 43-N+1 to bit 43.

[0224] As described above in FIG. 11, in the PAID calculation process, the lower 5 bits of y are all set to 0 (i.e., "00000"). In this case, when bits 5 to 8 of AID are set according to the rule of Equation 23, PAID[5:8] has a fixed value within the BSS. Therefore, when AID is assigned according to the rule of Equation 23, ambiguity in determining the PAID value is prevented.

[0225] Also, if the AID is assigned according to the rule of Equation 23, the K-bit value based on the BSSID (i.e., y in FIG. 11) is offset with the N-bit value based on the BSSID when setting the PAID according to the embodiment of Equation 1. Thus, the pre-configured bits of the PAID (i.e., PAID[8-N+1:8]) indicate the partial BSS color value known to the intended recipient of the corresponding frame. Thus, if the received frame is a VHT PPDU (and the group ID extracted from the received frame is 63), the terminal compares the pre-configured bits of the PAID extracted from the received frame with the partial BSS color known to the terminal to determine whether the frame is an intra-BSS frame or an inter-BSS frame. In this case, the pre-configured bits of the PAID are the pre-configured 4-bits of the PAID, i.e., the value of PAID[5:8]. If the pre-configured bits of the PAID match the partial BSS color known to the terminal, the terminal determines that the received frame is an intra-BSS frame. However, if the PAID preset bits do not match the partial BSS color known to the terminal, the terminal determines the received frame to be an inter-BSS frame.

[0226] According to an embodiment of the present invention, since the pre-configured bits of the PAID indicate a partial BSS color value, a terminal receiving the corresponding frame can determine whether it is an intra-BSS frame or an inter-BSS frame using the PAID information without the need to acquire or calculate additional information.

[0227] 25 is a diagram showing a non-legacy element format according to another embodiment of the present invention. Among the fields of the non-legacy element in FIG. 25, duplicated descriptions will be omitted for the same parts as the fields of the non-legacy element described in the above embodiment.

[0228] 25, the non-legacy element includes an "element ID" field, a "length" field, and an "HE Operational Parameters" field. The "HE Operational Parameters" field also includes a "BSS Color" field and a "Partial BSS Color Indication" field. According to one embodiment, the "HE Operational Parameters" field of the non-legacy element includes a 6-bit "BSS Color" field and a 1-bit "Partial BSS Color Indication" field.

[0229] The 'BSS color' field indicates a BSS color value as described above in FIG. 23. The 'partial BSS color bit indication' field indicates whether the corresponding BSS applies an AID allocation rule using partial BSS color bits. If the field is set to 1, an N-bit (here, N is 4) partial BSS color value is used for AID allocation. However, if the field is set to 0, the partial BSS color is not used for AID allocation. In addition, the 'partial BSS color bit indication' field indicates whether a method of determining intra / inter-BSS frames using PAID information of a VHT PPDU is used. According to the embodiment of FIG. 24, the number N of partial BSS color bits used for AID allocation is fixed. Therefore, the non-legacy element indicates whether the partial BSS color is used for AID allocation through the 1-bit 'partial BSS color bit indication' field.

[0230] Figure 26 illustrates an AID allocation method according to a seventh embodiment of the present invention. Figure 26(a) illustrates an AID allocation method when N is not 4, and Figure 26(b) illustrates an AID allocation method when N is 4. Here, N represents the number of bits of the partial BSS color used for AID allocation.

[0231] First, referring to FIG. 26(a), if N is not 4, the AID allocation method according to the seventh embodiment of the present invention can be expressed as Equation 24 below.

[0232]

number

[0233] where A[0:3-N] is an arbitrary (3-N+1)-bit binary number.

[0234] Next, referring to FIG. 26(b), if N is 4, the AID allocation method according to the seventh embodiment of the present invention is expressed as Equation 25 below.

[0235]

number

[0236] Referring to Equation 24 and Equation 25, bits 5 to 8 of the AID are set according to the AID allocation method according to the seventh embodiment of the present invention. According to the seventh embodiment of the present invention, bits 5 to 8 of the AID are determined based on a value obtained by subtracting BSSID information from a value based on BCB information. In this case, the BCB information refers to a partial BSS color, and the BSSID information refers to a value of N-bits based on the BSSID. More specifically, the value of N-bits based on the BSSID may be an exclusive OR of a value of bits 44 to 47 of the BSSID and a value of bits 40 to 43 of the BSSID.

[0237] When the AID is assigned according to the rules of Equation 24 and Equation 25, the K-bit value based on the BSSID (i.e., y in FIG. 11) is offset with the N-bit value based on the BSSID when setting the PAID according to the embodiment of Equation 1. Thus, the pre-configured bits of the PAID (i.e., PAID[8-N+1:8]) indicate the partial BSS color value known to the intended recipient of the frame. Thus, if the received frame is a VHT PPDU (and the group ID extracted from the received frame is 63), the terminal compares the pre-configured bits of the PAID extracted from the received frame with the partial BSS color known to the terminal to determine whether the frame is an intra-BSS frame or an inter-BSS frame.

[0238] Hereinafter, the reason why the preset bits of PAID (i.e., PAID[8-N+1:8]) indicate the partial BSS color value (i.e., BCB[0:N-1]) when the AID allocation method according to the seventh embodiment of the present invention is used will be described in more detail. First, referring to Equation 1, PAID[5:8] is determined as follows:

[0239]

number

[0240] (Case A) If N is not 4 If N is not 4, AID[5:8] is set according to the rule of Equation 24. Referring to Equation 24, AID[5:8] is determined to be a variable value by A[0:3-N]. In this case, the upper N-bit(s) of AID[5:8] is determined based on BCB[0:N-1], and the remaining bit(s) of AID[5:8] indicates a variable value by A[0:3-N].

[0241] (Case A-1) (dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])-dec(BSSID[44:47] XOR BSSID[40:43])) ≥ 0 Substituting Equation 24 into Equation 26 gives the following equation:

[0242]

number

[0243] Referring to Equation 27, the only factor affecting PAID[8-N+1:8] is dec(BCB[0:N-1])*2^(4-N). Therefore, PAID[8-N+1:8] has the same value as BCB[0:N-1].

[0244] (Case A-2) (dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])-dec(BSSID[44:47] XOR BSSID[40:43]))<0 Substituting Equation 24 into Equation 26 gives the following equation:

[0245]

number

[0246] Referring to Equation 28, the only factor affecting PAID[8-N+1:8] is dec(BCB[0:N-1])*2^(4-N). Therefore, PAID[8-N+1:8] has the same value as BCB[0:N-1].

[0247] (Case B) When N is 4 If N is 4, then AID[5:8] is set according to the rules of Equation 25.

[0248] (Case B-1) dec(BCB[0:3]-dec(BSSID[44:47] XOR BSSID[40:43]) ≥ 0 Substituting Equation 25 into Equation 26 gives the following equation:

[0249]

number

[0250] Referring to Equation 26, PAID[8-N+1:8] has the same value as BCB[0:N-1] (where N is 4).

[0251] (Case B-2) dec(BCB[0:3]-dec(BSSID[44:47] XOR BSSID[40:43])<0 Substituting formula 25 into formula 26 gives the following formula.

[0252]

number

[0253] Referring to Equation 30, PAID[8-N+1:8] has the same value as BCB[0:N-1] (where N is 4).

[0254] Thus, in all cases, the set bits of PAID, i.e., PAID[8-N+1:8], will have the same value as the fractional BSS color value, i.e., BCB[0:N-1].

[0255] 27 is a diagram illustrating a method for determining whether an intra-BSS frame or an inter-BSS frame is included in a fourth embodiment of the present invention. The method for determining whether an intra-BSS frame or an inter-BSS frame is included in a fourth embodiment of the present invention is used when an AID is assigned according to the sixth embodiment described in FIG. 24 and the seventh embodiment described in FIG. 26.

[0256] First, the terminal receives a wireless frame and extracts group ID and PAID information from the received frame (S2710). If the received frame is a VHT PPDU, the RXVECTOR parameter of the frame includes group ID and PAID. Therefore, if the received frame is a VHT PPDU, the terminal extracts group ID and PAID information from the preamble of the VHT PPDU.

[0257] Next, the terminal checks what information the extracted group ID indicates (S2720). More specifically, the terminal checks whether the extracted group ID information is 0 or 63. As described above in the embodiment of FIG. 8, group ID 0 indicates that the corresponding frame is an upstream frame. Also, group ID 63 indicates that the corresponding frame is a downstream frame. That is, the terminal identifies whether the corresponding frame is an upstream frame or a downstream frame through the extracted group ID information.

[0258] If the extracted group ID information is 0 (i.e., an uplink frame is indicated), the terminal checks whether the PAID extracted from the frame matches a specific bit value of the BSSID of the BSS to which the terminal is associated (S2730). In this case, the specific bit value of the BSSID is BSSID[39:47]. As described above in FIG. 8, if it is an uplink frame, the PAID is set to BSSID[39:47], so the terminal determines whether the corresponding frame is an intra-BSS frame or an inter-BSS frame depending on whether the PAID of the received frame matches the BSSID[38:47] of the BSS to which the terminal is associated. If the PAID matches the BSSID[39:47], the terminal determines the received frame to be an intra-BSS frame (S2732). However, if the PAID does not match the BSSID[39:47], the terminal determines the received frame to be an inter-BSS frame (S2734).

[0259] On the other hand, if the extracted group ID information is 63 (i.e., indicates a downlink frame), the terminal checks whether the PAID extracted from the frame matches the partial BSS color known to the terminal (S2740). At this time, the PAID information refers to the preset bit(s) of PAID. In the embodiment of FIG. 27, the preset bit(s) of PAID refers to PAID[8-N+1:8]. According to another embodiment of the present invention, N=4. Also, the partial BSS color known to the terminal refers to the partial BSS color known by the AP to which the terminal is associated. When the AID is assigned according to the sixth or seventh embodiment of the present invention, if the PAID is set, the K-bit value based on the BSSID is offset with the N-bit value based on the BSSID. Therefore, the preset bit of PAID (i.e., PAID[8-N+1:8]) indicates the partial BSS color known to the intended recipient of the frame. Therefore, the terminal determines whether the corresponding frame is an intra-BSS frame or an inter-BSS frame depending on whether the preset bits of the PAID of the received frame match the partial BSS color known to the terminal. If the preset bits of the PAID match the partial BSS color known to the terminal, the terminal determines the received frame as an intra-BSS frame (S2742). However, if the preset bits of the PAID do not match the partial BSS color known to the terminal, the terminal determines the received frame as an inter-BSS frame (S2744).

[0260] According to one embodiment of the present invention, if the extracted group ID information is 63, the method of determining whether it is an intra-BSS frame or an inter-BSS frame is performed only if the value N of the "Number of partial BSS color bits used for AID" field of the non-legacy element most recently received from the associated AP is not 0. According to another embodiment of the present invention, if the extracted group ID information is 63, the method of determining whether it is an intra-BSS frame or an inter-BSS frame is performed only if the "Partial BSS color bit indication" field of the non-legacy element most recently received from the associated AP is set to 1. As described above, if the "Partial BSS color bit indication" field is set to 1, the AID allocation rule using the partial BSS color bit is applied.

[0261] Meanwhile, the AID allocation method according to the above embodiment is only applied when allocating AIDs for VHT STAs. AID allocation candidate values ​​are limited, and if a partial BSS color is used for AID allocation, the values ​​allocated to AIDs are further reduced. Therefore, according to the embodiment of the present invention, the above AID allocation method is applied only to VHT STAs, so that it is possible to secure a margin of AID allocation for all STAs.

[0262] Although the present invention has been described above using wireless LAN communication as an example, the present invention is not limited thereto and can be equally applied to other communication systems such as cellular communication, etc. Also, although the method, apparatus and system of the present invention have been described with reference to specific embodiments, some or all of the components and operations of the present invention may be implemented using a computer system having a general-purpose hardware architecture.

[0263] The above-described embodiments of the present invention may be implemented in a variety of ways, for example, in hardware, firmware, software, or a combination thereof.

[0264] In the case of a hardware implementation, the methods according to the embodiments of the present invention may be implemented using one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0265] In the case of implementation by firmware or software, the method according to the embodiment of the present invention may be implemented in the form of modules, procedures, or functions that perform the functions or operations described above. The software code is stored in a memory and implemented by a processor. The memory may be located inside or outside the processor and may exchange data with the processor by various means known in the art.

[0266] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above-described embodiments should be interpreted as illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed form, and each component described as a distributed form may be implemented in a combined form.

[0267] The scope of the present invention is indicated by the claims set forth below rather than by the above detailed description, and all modifications and variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. [Industrial Applicability]

[0268] Although various embodiments of the present invention have been described with reference to an IEEE 802.11 system, the present invention may be applied to various other types of mobile communication devices, mobile communication systems, and the like. [Explanation of symbols]

[0269] 100 Stations 110 Processor 120 Communications Department 140 User Interface Section 150 display units 160 Memory 210 Processor 220 Communications Department 260 Memory 300 Servers

Claims

1. A wireless communication terminal, comprising: A processor; A communication unit, The processor, receiving a wireless frame via the communication unit; The radio frame includes an association identifier (AID) and a subfield indicating whether an AID allocation rule is applied to the allocation of the AID, If the subfield indicates application of the AID allocation rule, the preset N bits of the AID are determined using a partial BSS color bit of a BSS color of a Basic Service Set (BSS) and an N-bit value based on a BSS identifier (BSSID) of the BSS; The BSS color and / or the BSSID are used to identify whether a PPDU (physical layer protocol data unit) is an inter-BSSPPDU or an intra-BSSPPDU, Identifying whether the AID is assigned according to the AID assignment rule based on the subfield; The predetermined N bits of the AID are determined based on a value obtained by subtracting the N bit value from the partial BSS color bits.

2. The wireless communication terminal of claim 1 , wherein the AID allocation rule relates to whether the partial BSS color bits are used for allocation of the AID.

3. the fractional BSS color bits being the least significant N bits or the most significant N bits of the BSS color; The wireless communication terminal according to claim 1 , wherein the N-bit value based on the BSSID is a value of an exclusive OR of a first preset N bits and a second preset N bits of the BSSID.

4. 2. The wireless communication terminal according to claim 1, wherein said N is four.

5. The AID allocation rule is expressed by the following formula: [0010] 2. The wireless communication terminal according to claim 1, wherein the BCB is the BSS color, the BSSID is a BSS identifier, and N is four.

6. A wireless communication method for a station (STA), comprising: receiving a radio frame, the radio frame including an association identifier (AID) and a subfield indicating whether an AID allocation rule is applied to the allocation of the AID; If the subfield indicates application of the AID allocation rule, the preset N bits of the AID are determined using a partial BSS color bit of a BSS color of a Basic Service Set (BSS) and an N-bit value based on a BSS identifier (BSSID) of the BSS; the BSS color and / or the BSSID are used to identify whether a physical layer protocol data unit (PPDU) is an inter-BSSPPDU or an intra-BSSPPDU; identifying whether the AID is assigned according to the AID assignment rule based on the subfield, wherein the preset N bits of the AID are determined based on the partial BSS color bits minus the N bit value; A wireless communication method comprising:

7. The wireless communication method of claim 6 , wherein the AID allocation rule relates to whether the partial BSS color bits are used for allocation of the AID.

8. the fractional BSS color bits being the least significant N bits or the most significant N bits of the BSS color; The wireless communication method of claim 6 , wherein the N-bit value based on the BSSID is an exclusive-OR value of a first preset N bits and a second preset N bits of the BSSID.

9. The wireless communication method according to claim 6 , wherein N is four.

10. The AID allocation rule is expressed by the following formula: [0025] 7. The wireless communication method of claim 6, wherein the BCB is the BSS color, the BSSID is a BSS identifier, and N is four.

Images