Wireless communication method and wireless communication terminal

Abstract

The present invention relates to a wireless communication method and a wireless communication terminal, and more particularly, to a wireless communication method and a wireless communication terminal that perform an operation based on a result of determining whether a received frame is an intra-BSS frame or an inter-BSS frame. To this end, the present invention provides a wireless communication terminal and a wireless communication method using the same, the wireless communication terminal including: a processor; and a communication unit, the processor receiving a wireless frame through the communication unit, extracting partial Association ID (AID) information and group ID information from a preamble of a VHT PPDU if the received frame is the VHT PPDU, confirming whether at least some of the extracted partial AID matches a partial BSS color known by the terminal if the extracted group ID information is equal to a predetermined value, and determining whether the received frame is an intra-BSS frame or an inter-BSS frame based on whether at least some of the partial AID matches the partial BSS color.

Description

[0001] This application is a divisional application of the patent application with application number 201780021591.2 (PCT / KR2017 / 003661) filed on September 29, 2018, with an international filing date of April 3, 2017, and the invention name being “Wireless communication method and wireless communication terminal for determining basic service set identification information of received frames”. Technical Field

[0002] The present invention relates to a wireless communication method and a wireless communication terminal for determining basic service set identification information of a received frame, and more particularly, to a wireless communication method and a wireless communication terminal for performing an operation based on a determination result of whether the received frame is an intra-BSS frame or an inter-BSS frame. Background Art

[0003] In recent years, with the expansion of mobile devices, wireless LAN technology, which can provide fast wireless Internet services to mobile devices, has gained attention. Wireless LAN technology allows mobile devices, including smartphones, smart tablets, laptops, portable multimedia players, embedded devices, etc., to wirelessly access the Internet at home, work, or in a specific service provider area based on short-range wireless communication technology.

[0004] Since using the frequency of 2.4GHz to support the initial wireless LAN technology, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has been commercialized or developed various technical standards. First, IEEE 802.11b supports a communication speed of maximum 11Mbps when using the frequency of the 2.4GHz band. Compared with the frequency of the significantly congested 2.4GHz band, the IEEE 802.11a commercialized after IEEE802.11b uses the frequency of the 5GHz band instead of the 2.4GHz band to reduce the influence of interference, and by using OFDM technology, the communication speed is increased to a maximum of 54Mbps. However, the shortcoming of IEEE 802.11a is that the communication distance is shorter than that of IEEE 802.11b. In addition, similar to IEEE 802.11b, IEEE 802.11g uses the frequency of the 2.4GHz band to achieve a communication speed of maximum 54Mbps and meets backward compatibility to significantly attract attention, and is superior to IEEE 802.11a in terms of communication distance.

[0005] In addition, as a technical standard established to overcome the limitation of communication speed pointed out as a weakness in wireless LAN, IEEE 802.11n has been provided. IEEE 802.11n aims to improve the speed and reliability of the network and extend the working distance of the wireless network. In more detail, IEEE 802.11n supports high throughput (HT), wherein the data processing speed is a maximum of 540Mbps or higher, and further, based on multiple-input and multiple-output (MIMO) technology, wherein multiple antennas are used on both sides of the transmitting unit and the receiving unit to minimize transmission errors and optimize data speed. In addition, the standard can use a coding scheme that sends multiple copies superimposed on each other to increase data reliability.

[0006] With the increasing deployment of wireless LANs and the further diversification of wireless LAN application applications, demand has grown for new wireless LAN systems supporting higher throughput (Very High Throughput (VHT)) than the data processing speeds supported by IEEE 802.11n. Among these, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) in the 5 GHz frequency band. While the IEEE 802.11ac standard is defined only in the 5 GHz band, initial 11ac chipsets also support operation in the 2.4 GHz band for backward compatibility with existing 2.4 GHz band products. Theoretically, this standard can enable wireless LAN speeds of at least 1 Gbps for multiple stations and a maximum single-link speed of at least 500 Mbps. This is achieved by expanding upon the wireless interface concepts adopted by 802.11n, including wider wireless bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256QAM). IEEE 802.11ad has also been introduced as a solution for transmitting data using the 60 GHz band instead of the existing 2.4 GHz / 5 GHz band. IEEE 802.11ad is a transmission standard that uses beamforming technology to provide a maximum speed of 7 Gbps and is suitable for streaming high-bitrate moving images such as massive data or uncompressed HD video. However, since the 60 GHz band has difficulty passing through obstacles, its disadvantage is that it can only be used by devices in close proximity.

[0007] Meanwhile, in recent years, discussions have been ongoing on technologies that provide efficient and high-performance wireless LAN communication in high-density environments, as the next-generation wireless LAN standards following 802.11ac and 802.11ad. Specifically, in next-generation wireless LAN environments, high-spectrum-efficient communication is required both indoors and outdoors in the presence of a high density of stations and access points (APs), and various technologies are needed to achieve this communication. Summary of the Invention

[0008] Technical issues

[0009] The present invention has an object to provide high-efficiency / high-performance wireless LAN communication in a high-density environment as described above.

[0010] In addition, the present invention has the purpose of setting rules for AID assignment of STAs in a BSS.

[0011] In addition, the present invention has an object of preventing ambiguity that may occur in intra / inter-BSS determination using partial AID information of a VHT PPDU.

[0012] Technical Solution

[0013] To achieve these objectives, the present invention provides a wireless communication method and a wireless communication terminal as follows.

[0014] First, exemplary embodiments of the present invention provide a basic wireless communication terminal, the terminal including: a processor; and a communication unit, wherein the processor assigns an association ID (AID) to at least one terminal associated with the basic wireless communication terminal, wherein predetermined N bits of the AID are determined based on a value obtained by subtracting an N-bit value based on the BSSID from a partial BSS color value.

[0015] Furthermore, exemplary embodiments of the present invention provide a wireless communication method of a basic wireless communication terminal, including: assigning an association ID (AID) to at least one terminal associated with the basic wireless communication terminal; and transmitting the assigned AID information to the terminal associated with the basic wireless communication terminal, wherein predetermined N bits of the AID are determined based on a value obtained by subtracting an N-bit value based on the BSSID from a partial BSS color value.

[0016] The partial BSS color value may be a value of the least significant N bits or the most significant N bits of the BSS color, and the BSSID-based N-bit value may be an exclusive OR value of a first predetermined N bits of the BSSID and a second predetermined N bits of the BSSID.

[0017] According to an embodiment of the present invention, N is 4.

[0018] According to an embodiment of the present invention, the AID is determined by the following equation.

[0019] AID(8-N+1:8)=bin[(dec(BCB(0:N-1))-dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod2^N,N]

[0020] Here, BCB is a BSS color, BSSID is a BSS identifier, and N=4.

[0021] When the basic wireless communication terminal transmits a VHT PPDU to the first terminal, the processor may set a partial AID using the AID information of the first terminal determined by the subtraction operation and the K-bit value based on the BSSID, and may transmit the set partial AID information by including it in the preamble of the VHT PPDU.

[0022] The predetermined N bits of the partial AID may represent a partial BSS color value, wherein the BSSID-based N-bit value is offset by the BSSID-based K-bit value.

[0023] Part of the AID information may be included in the VHT-SIG-A of the VHT PPDU.

[0024] Next, another exemplary embodiment of the present invention provides a wireless communication terminal, the terminal including: a processor; and a communication unit, wherein when the received frame is a VHT PPDU, the processor receives the wireless frame through the communication unit, extracts partial association ID (AID) information and group ID information from a preamble of the VHT PPDU when the extracted group ID information is equal to a predetermined value, checks whether at least some information of the extracted partial AID matches a partial basic service set (BSS) color advertised to the terminal, and determines whether the received frame is an intra-BSS frame or an inter-BSS frame based on whether at least some information of the partial AID matches the partial BSS color.

[0025] In addition, another exemplary embodiment of the present invention provides a wireless communication method of a wireless communication terminal, including: receiving a wireless frame through a communication unit; when the received frame is a VHT PPDU, extracting partial association ID (AID) information and group ID information from a preamble of the VHT PPDU; 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 advertised to the terminal; and determining whether the received frame is an intra-BSS frame or an inter-BSS frame based on whether at least some information of the partial AID matches the partial BSS color.

[0026] The partial AID may be determined using the AID assigned to the intended recipient of the VHT PPDU and a K-bit value based on the BSSID of the BSS associated with the recipient. When the BSS to which the terminal belongs applies an AID assignment rule that uses partial BSS color bits, the predetermined N bits of the AID assigned in the BSS to which the terminal belongs may be determined using the partial BSS color value announced to the terminal and an N-bit value based on the BSSID of the BSS to which the terminal belongs, and N may be equal to K.

[0027] The predetermined N bits of the AID assigned in the BSS to which the terminal belongs may be 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 announced to the terminal.

[0028] When the BSS to which the receiver belongs applies an AID assignment rule in which partial BSS color bits are used, predetermined bits of the partial AID may represent a partial BSS color value announced to the receiver, where a K-bit value based on the BSSID is offset by an N-bit value based on the BSSID of the BSS associated with the receiver.

[0029] The partial BSS color value may be a value of the least significant N bits or the most significant N bits of the BSS color, and the BSSID-based N-bit value may be an exclusive OR value of a first predetermined N bits of the BSSID and a second predetermined N bits of the BSSID.

[0030] According to an embodiment of the present invention, N is 4.

[0031] According to an embodiment of the present invention, the AID is determined by the following equation.

[0032] AID(8-N+1:8)=bin[(dec(BCB(0:N-1))-dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod2^N,N]

[0033] Here, BCB is a BSS color, BSSID is a BSS identifier, and N=4.

[0034] The predetermined value of the group ID information may indicate that the frame is a downlink frame.

[0035] When the received frame is determined to be an intra-BSS frame, the processor may perform a first operation, and when the received frame is determined to be an inter-BSS frame, the processor may perform a second operation.

[0036] When the received frame is determined to be an intra-BSS frame, the processor can determine whether the channel is busy based on a first CCA threshold, and when the received frame is determined to be an inter-BSS frame, the processor can determine whether the channel is busy based on both the first CCA threshold and a second CCA threshold different from the first CCA threshold.

[0037] The second CCA threshold may have a value equal to or higher than the first CCA threshold.

[0038] When the received frame is determined to be an intra-BSS frame, the processor may set or update a first network allocation vector (NAV), and when the received frame is determined to be an inter-BSS frame, the processor may set or update a second NAV.

[0039] Beneficial effects

[0040] According to an embodiment of the present invention, at least some information of a partial AID of a VHT PPDU may indicate a partial BSS color value, enabling efficient BSS intra / inter frame determination.

[0041] More specifically, according to an embodiment of the present invention, a terminal receiving a VHT PPDU can perform determination of an intra-BSS frame and an inter-BSS frame using partial AID information without obtaining additional information or performing additional calculations.

[0042] In addition, according to an embodiment of the present invention, if a received frame is determined to be an inter-BSS frame, it is thereby possible to efficiently use wireless resources to perform a spatial reuse operation.

[0043] According to the embodiments of the present invention, it is possible to increase the total resource utilization in a contention-based channel access system and improve the performance of a wireless LAN system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A wireless LAN system according to an embodiment of the present invention is illustrated.

[0045] Figure 2 A wireless LAN system according to another embodiment of the present invention is shown.

[0046] Figure 3 The diagram illustrates a configuration of a station according to an embodiment of the present invention.

[0047] Figure 4 FIG. 1 illustrates a configuration of an access point according to an embodiment of the present invention.

[0048] Figure 5 The diagram schematically illustrates the process of link establishment between a STA and an AP.

[0049] Figure 6 The diagram illustrates a carrier sense multiple access (CSMA) / collision avoidance (CA) method used in wireless LAN communications.

[0050] Figure 7 The configurations of VHT-SIG-A1 and VHT-SIG-A2 according to an embodiment of the present invention are illustrated.

[0051] Figure 8 is a table illustrating a method of setting a group ID and a partial AID according to an embodiment of the present invention.

[0052] Figure 9 Illustrated is a non-traditional element format according to an embodiment of the present invention.

[0053] Figure 10 FIG. 4 illustrates a partial AID calculation process according to an embodiment of the present invention.

[0054] Figure 11 Part of the AID calculation process according to an embodiment of the present invention is illustrated in more detail.

[0055] Figure 12 FIG. 1 shows a first embodiment of a method for determining an intra-BSS frame and an inter-BSS frame according to the present invention.

[0056] Figure 13 FIG. 2 shows a second embodiment of a method for determining an intra-BSS frame and an inter-BSS frame according to the present invention.

[0057] Figure 14 A process of calculating a reference value and a process of calculating a partial AID for BSS intra / inter frame determination according to an embodiment of the present invention are illustrated.

[0058] Figure 15 A non-traditional element format according to another embodiment of the present invention is shown.

[0059] Figure 16 A method of signaling information on the number of partial BSS color bits and ambiguity information according to another embodiment of the present invention is illustrated.

[0060] Figure 17 FIG. 2 shows a second embodiment of an AID assignment method and a non-legacy element format according to the present invention.

[0061] Figure 18 FIG. 3 shows a third embodiment of the AID assignment method according to the present invention.

[0062] Figure 19 FIG. 4 shows a fourth embodiment of the AID assignment method according to the present invention.

[0063] Figure 20 and 21 FIG. 5 shows a fifth embodiment of the AID assignment method according to the present invention.

[0064] Figure 22 FIG. 3 illustrates a method for determining intra-BSS frames and inter-BSS frames according to a third embodiment of the present invention.

[0065] Figure 23 A non-traditional element format according to yet another embodiment of the present invention is illustrated.

[0066] Figure 24 FIG. 6 shows a sixth embodiment of the AID assignment method according to the present invention.

[0067] Figure 25 A non-traditional element format according to yet another embodiment of the present invention is illustrated.

[0068] Figure 26 FIG. 7 shows a seventh embodiment of the AID assignment method according to the present invention.

[0069] Figure 27 FIG. 4 shows a fourth embodiment of a method for determining an intra-BSS frame and an inter-BSS frame according to the present invention. DETAILED DESCRIPTION

[0070] By taking into account the functions of the present invention, the terms used in this specification adopt the general terms currently in wide use. However, the terms may be changed according to the intentions, habits, and emergence of new technologies of those skilled in the art. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in such cases, their meanings will be described in the corresponding description section of the present invention. Therefore, it should be understood that the terms used in this specification should be analyzed not only based on the name of the term, but also based on the substantive meaning of the term and the content of the entire specification.

[0071] Throughout this specification and the claims that follow, when it is described that an element is "coupled" to another element, the element may be "directly coupled" to the other element or "electrically coupled" to the other element via a third element. Furthermore, unless expressly stated to the contrary, the word "comprise" and variations such as "comprising" or "including" will be understood to implicitly include the stated elements but not to exclude any other elements. Furthermore, limitations based on specific thresholds such as "or above" or "or below" may be replaced with "greater than" or "less than," respectively, as appropriate.

[0072] This application claims priority to and the benefit of Korean Patent Applications Nos. 10-2016-0040551, 10-2016-0093812, and 10-2016-0102229 filed in the Korean Intellectual Property Office, and the embodiments and matters described in the corresponding applications, which formed the basis of the claim of priority, are to be included in the detailed description of this application.

[0073] Figure 1 1 is a diagram illustrating a wireless LAN system according to an embodiment of the present invention. The wireless LAN system includes one or more basic service sets (BSSs), and a BSS represents a group of devices that are successfully synchronized with each other to communicate with each other. Generally, a BSS can be divided into an infrastructure BSS and an independent BSS (IBSS), and Figure 1 The diagram shows the basic structure BSS between them.

[0074] As in Figure 1 As shown in the figure, the infrastructure BSS (BSS1 and BSS2) includes one or more stations STA1, STA2, STA3, STA4 and STA5, access points PCP / AP-1 and PCP / AP-2 of the stations providing distributed services, and a distribution system (DS) connecting multiple access points PCP / AP-1 and PCP / AP-2.

[0075] A station (STA) is a predetermined device that includes a medium access control (MAC) and a physical layer interface for a wireless medium in accordance with the provisions of the IEEE 802.11 standard, and broadly includes both non-access point (non-AP) stations and access points (APs). In addition, in this specification, the term "terminal" may be used to refer to a non-AP STA, or an AP, or both. A station for wireless communication includes a processor and a communication unit, and according to this embodiment, may further include a user interface unit and a display unit. The processor may generate frames to be transmitted via a wireless network, or process frames received via a wireless network, and furthermore, perform various processes for controlling the station. In addition, the communication unit is functionally connected to the processor, and transmits and receives frames via the wireless network for the station. According to the present invention, a terminal may be used as a term that includes a user equipment (UE).

[0076] An access point (AP) is an entity that provides access to a distribution system (DS) via a wireless medium for stations associated with it. In an infrastructure BSS, communication between non-AP stations is generally performed via the AP, but when a direct link is configured, direct communication is even allowed between non-AP stations. Meanwhile, in the present invention, AP is used as a concept that includes a personal BSS coordination point (PCP), and in a broad sense can include concepts including a central controller, base station (BS), Node B, base transceiver system (BTS), and site controller. In the present invention, AP can also be referred to as a base station wireless communication terminal. Base station wireless communication terminal can be used as a term that, in a broad sense, includes APs, base stations, eNBs (i.e., eNode Bs), and transmission points (TPs). Furthermore, base station wireless communication terminals can include various types of wireless communication terminals that allocate media resources and perform scheduling for communications with multiple wireless communication terminals.

[0077] Multiple infrastructure BSSs may be connected to each other via a distribution system (DS). In this case, the multiple BSSs connected via the distribution system are called an extended service set (ESS).

[0078] Figure 2 The figure shows an independent BSS according to another embodiment of the present invention, which is a wireless LAN system. Figure 2 In the embodiment of Figure 1 Repetitive description of parts of the embodiments will be omitted.

[0079] Because in Figure 2 The BSS3 shown in FIG is an independent BSS and does not include an AP. All stations STA6 and STA7 are not connected to the AP. Independent BSSs are not allowed to access the distribution system and form a self-contained network. In an independent BSS, corresponding stations STA6 and STA7 can directly connect to each other.

[0080] Figure 3 is a block diagram illustrating the configuration of a station 100 according to one embodiment of the present invention. Figure 3 As illustrated in FIG, a station 100 according to an embodiment of the present invention may include a processor 110 , a communication unit 120 , a user interface unit 140 , a display unit 150 , and a memory 160 .

[0081] First, the communication unit 120 transmits and receives wireless signals, such as wireless LAN packets, and can be embedded in the station 100 or provided as a peripheral. Depending on the embodiment, the communication unit 120 may include at least one communication module that uses different frequency bands. For example, the communication unit 120 may include communication modules with different frequency bands, such as 2.4 GHz, 5 GHz, and 60 GHz. According to one embodiment, the station 100 may include a communication module that uses a frequency band of 6 GHz or above, and a communication module that uses a frequency band of 6 GHz or below. The respective communication modules may perform wireless communications with an AP or external station according to the wireless LAN standard of the frequency band supported by the respective communication module. Depending on the performance and requirements of the station 100, the communication unit 120 may operate only one communication module at a time, or may operate multiple communication modules simultaneously. When the station 100 includes multiple communication modules, each communication module may be implemented as a separate component, or the multiple modules may be integrated into a single chip. In embodiments of the present invention, the communication unit 120 may represent a radio frequency (RF) communication module for processing RF signals.

[0082] Second, the user interface unit 140 includes various types of input / output devices provided in the station 100. That is, the user interface unit 140 can receive user input by using various input devices, and the processor 110 can control the station 100 based on the received user input. In addition, the user interface unit 140 can perform output based on the command of the processor 110 by using various output devices.

[0083] Next, the display unit 150 outputs an image on the display screen. The display unit 150 can output various display objects, such as content executed by the processor 110 or a user interface, based on the control command of the processor 110. In addition, the memory 160 stores control programs used in the station 100 and various result data. The control program may include an access program required for the station 100 to access the AP or an external station.

[0084] The processor 110 of the present invention can execute various commands or programs and process data within the station 100. Furthermore, the processor 110 can control various units of the station 100 and control data transmission / reception within the units. According to an embodiment of the present invention, the processor 110 can execute a program for accessing an AP stored in the memory 160 and receive a communication configuration message sent by the AP. Furthermore, the processor 110 can read information regarding the priority conditions of the station 100 included in the communication configuration message and request access to the AP based on the information regarding the priority conditions of the station 100. The processor 110 of the present invention can represent the main control unit of the station 100. Depending on the embodiment, the processor 110 can also represent a control unit for individually controlling certain components of the station 100, such as the communication unit 120. Specifically, the processor 110 can be a modem or modulator / demodulator for modulating wireless signals transmitted to the communication unit 120 and demodulating wireless signals received from the communication unit 120. According to an embodiment of the present invention, the processor 110 controls various operations of wireless signal transmission / reception within the station 100. Detailed embodiments of this control are described below.

[0085] exist Figure 3 The station 100 shown in FIG. 1 is a block diagram according to one embodiment of the present invention, where individual blocks are illustrated as components of a logically distinct device. Therefore, the components of the device may be implemented in a single chip or multiple chips, depending on the design of the device. For example, the processor 110 and the communication unit 120 may be implemented as an integrated single chip or as separate chips. Furthermore, in embodiments of the present invention, certain 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.

[0086] Figure 4 is a block diagram illustrating the configuration of an AP 200 according to one embodiment of the present invention. Figure 4 As shown in FIG, the AP 200 according to an embodiment of the present invention may include a processor 210, a communication unit 220, and a memory 260. Figure 4 Among the components of AP200, Figure 2 The components of station 100 are the same as or correspond to Figure 2A repeated description of parts of the components of the station 100 will be omitted.

[0087] refer to Figure 4 , the AP 200 according to the present invention includes a communication unit 220 that operates a BSS in at least one frequency band. Figure 3 As described in the embodiment of the present invention, the communication unit 220 of the AP 200 may also include multiple communication modules using different frequency bands. That is, the AP 200 according to the embodiment of the present invention may include two or more communication modules in different frequency bands, such as 2.4 GHz, 5 GHz, and 60 GHz. Preferably, the AP 200 may include a communication module using a frequency band of 6 GHz or above, and a communication module using a frequency band of 6 GHz or below. Each communication module may perform wireless communication with a station according to the wireless LAN 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, depending on the performance and requirements of the AP 200. In the embodiment of the present invention, the communication unit 220 may represent a radio frequency (RF) communication module for processing RF signals.

[0088] Next, the memory 260 stores control programs used by the AP 200 and various result data. The control programs may include access programs for managing station access. Furthermore, the processor 210 may control various units of the AP 200 and control data transmission / reception within the units. According to an embodiment of the present invention, the processor 210 may execute programs for accessing stations stored in the memory 260 and send communication configuration messages for one or more stations. In this case, the communication configuration message may include information regarding access priority conditions for each station. Furthermore, the processor 210 performs access configuration based on access requests from stations. According to one embodiment, the processor 210 may be a modem or modulator / demodulator for modulating wireless signals transmitted to the communication unit 220 and demodulating wireless signals received from the communication unit 220. According to an embodiment of the present invention, the processor 210 controls various operations, such as wireless signal transmission / reception of the AP 200. A detailed embodiment of this will be described below.

[0089] Figure 5 is a diagram schematically illustrating a process in which a STA sets up a link with an AP.

[0090] refer to Figure 5In a broad sense, a link between the STA 100 and the AP 200 is established via three steps of scanning, authentication, and association. First, the scanning step is a step in which the STA 100 obtains access information of the BSS operated by the AP 200. Methods for performing scanning include a passive scanning method in which the AP 200 obtains information by using a beacon message transmitted periodically (S101), and an active scanning method in which the STA 100 transmits a probe request to the AP (S103) and obtains access information by receiving a probe response from the AP (S105).

[0091] STA 100, which has successfully received wireless access information in the scanning step, performs an authentication step (S107b) by sending an authentication request (S107a) and receiving an authentication response from AP 200. After performing the authentication step, STA 100 performs an association step by sending an association request (S109a) and receiving an association response (S109b) from AP 200. In this specification, association generally refers to wireless association, but the present invention is not limited thereto, and association can broadly include both wireless association and wired association.

[0092] At the same time, an authentication step (S111) based on 802.1X and an IP address acquisition step (S113) via DHCP may be additionally performed. Figure 5 In FIG, the authentication server 300 is a server that processes 802.1X-based authentication for the STA 100 and may exist in physical association with the AP 200 or as a separate server.

[0093] Figure 6 The diagram illustrates a carrier sense multiple access (CSMA) / collision avoidance (CA) method used in wireless LAN communications.

[0094] A terminal performing wireless LAN communication checks whether a channel is busy by performing carrier sensing before sending data. When a wireless signal with a predetermined strength or above is sensed, the corresponding channel is determined to be busy, and the terminal delays access to the corresponding channel. Such a process is called clear channel assessment (CCA), and the level for determining whether the corresponding signal is sensed is called the CCA threshold. When a wireless signal with a CCA threshold or above received by a terminal indicates that the corresponding terminal is a receiver, the terminal processes the received radio signal. At the same time, when no wireless signal is sensed in the corresponding channel, or when a wireless signal with a strength less than the CCA threshold is sensed, the channel is determined to be idle.

[0095] When a channel is determined to be idle, each terminal with data to transmit performs a backoff procedure after an interframe space (IFS) period, such as arbitration IFS (AIFS), PCF IFS (PIFS), or the like, has elapsed, depending on the situation of each terminal. According to this embodiment, AIFS can be used as a component to replace the existing DCF IFS (DIFS). By determining a random number during an idle period in a channel, each terminal prepares for a decrease in slot time, and a terminal that has fully used up that slot attempts to access the corresponding channel. Therefore, the interval during which each terminal performs the backoff procedure is called a contention window interval.

[0096] When a specific terminal successfully accesses the channel, the corresponding terminal can send data via the channel. However, when the terminal attempting access conflicts with another terminal, the conflicting terminals are assigned new random numbers to respectively perform the backoff process again. According to one embodiment, it can be determined that the random number reassigned to each terminal is within a range (2*CW), which is twice the range (contention window, CW) of the random number previously assigned to the corresponding terminal. At the same time, each terminal attempts access by performing the backoff process again in the next contention window interval, and in this case, each terminal performs the backoff process starting from the time slot time maintained in the previous contention window interval. By such a method, each terminal performing wireless LAN communication can avoid conflict with each other for a specific channel.

[0097] Figure 7 The figure illustrates the configuration of VHT-SIG-A1 and VHT-SIG-A2 according to an embodiment of the present invention. The preamble of a VHT PHY protocol data unit (PPDU) includes a VHT-SIG-A field, and the VHT-SIG-A consists of VHT-SIG-A1 and VHT-SIG-A2. VHT-SIG-A1 and VHT-SIG-A2 carry information necessary to interpret the VHT PPDU.

[0098] refer to Figure 7 , the VHT-SIG-A1 of a single-user PPDU may include a partial association ID (AID) field consisting of 9 bits. The partial AID field may indicate abbreviated information about the intended recipient of the corresponding PHY service data unit (PSDU). In the case of a SU PPDU, the group ID field of the VHT-SIG-A1 is set to 0 or 63, and in the case of a multi-user (MU) PPDU, it is set to other values. The terminal may check the partial AID (or partial AID and group ID) of the received VHT PPDU and stop decoding if the intended recipient of the PPDU is not the terminal.

[0099] Hereinafter, a method for setting a partial AID and an AID according to an embodiment of the present invention will be described with reference to each of the accompanying drawings. For ease of explanation, each equation and symbol are defined as follows. According to an embodiment of the present invention, "[]" and "()" in each equation can be replaced with each other and have the same meaning.

[0100] -A[b:c] represents bits from bit b to bit c of "A". According to an embodiment of the present invention, the first bit of "A" may be bit 0, and A[b:c] may represent bit (b+1) to bit (c+1) of "A".

[0101] -dec(A[b:c]) represents the values ​​of bits b to c of "A" expressed as a decimal number. In this case, the value of bit b of "A" is scaled by 2^0, and the value of bit c of "A" is scaled by 2^(cb). dec(A[b:c]) and A[b:c] differ only in the type of information expression and represent essentially the same value.

[0102] bin[x, N] represents the value of "x" represented by an N-bit binary number.

[0103] -B(X) represents the bit at bit position X.

[0104] –XOR indicates bitwise exclusive OR.

[0105] -A mod X represents the result of the modulo X operation of "A". According to an embodiment of the present invention, even if A is negative, the result of A mod X is positive. For example, 5 mod 3 is 2, and -5 mod 3 is 1.

[0106] Figure 8 is a table illustrating a method of setting a group ID and a partial AID according to an embodiment of the present invention.

[0107] First, in a PPDU or PSDU addressed to an AP, the group ID is set to 0 and the partial AID is set to the BSSID [39:47]. The BSSID indicates the identifier of the BSS to which the terminal transmitting the corresponding PPDU or PSDU belongs. Because part of the BSSID information is set as the partial AID of the uplink frame, the partial AID of the uplink frame can have BSS identification capabilities.

[0108] Next, in a PPDU or PSDU addressed to a mesh STA, the group ID is set to 0 and the partial AID is set to RA[39:47]. RA indicates the receiver address of the corresponding PPDU or PSDU.

[0109] According to an embodiment of the present invention, in a PPDU or PSDU that satisfies the following conditions, the group ID may be set to 63, and the partial AID (hereinafter, PAID) may be set as shown in the following equation 1. i) A PPDU or PSDU (i.e., a downlink frame) sent by an AP and addressed to a STA associated with the AP. ii) A PPDU or PSDU sent by a direct link setup (DLS) STA or a tunneled direct link setup (TDLS) STA in a direct path to a DLS or TDLS peer STA

[0110] [Equation 1]

[0111] PAID=(dec(AID[0:8])+dec(BSSID[44:47]XOR BSSID[40:43])*2^5)mod 2^9

[0112] That is, the PAID is determined by combining the AID information and the BSSID information. More specifically, the PAID is determined based on the value obtained by adding the XOR of some bits of the BSSID to the value of some bits of the AID. During the summation of the AID and BSSID information, the PAID of the downlink frame may lose the BSS identification capability of STAs other than the intended recipient, depending on the AID setting rules. Meanwhile, in cases other than the conditions listed above, the group ID is set to 63 and the partial AID is set to 0.

[0113] The group ID information and PAID information set in this manner can be included in the VHT-SIG of the VHT PPDU. The AP transmitting the VHT PPDU determines the PAID information and BSSID information and transmits the PAID information by including it in the VHT-SIG. In this case, the AID information indicates the value of some bits of the AID assigned to the intended recipient of the corresponding PPDU. Furthermore, the BSSID information indicates a value based on the BSSID of the AP transmitting the PPDU and the BSS to which the PPDU recipient belongs. The BSSID-based value indicates the exclusive OR of some bits of the BSSID. More specifically, the BSSID-based value indicates the exclusive OR of a first predetermined K bits of the BSSID and a second predetermined K bits of the BSSID. As in the embodiment of Equation 1, K can be set to 4, the first predetermined K bits can indicate bits 44 to 47, and the second predetermined K bits can indicate bits 40 to 43. Hereinafter, in this embodiment of the present invention, the BSSID-based value used to set the PAID will be referred to as the "BSSID-based K-bit value." On the other hand, since the PAID is determined according to the AID, a different value can be determined according to the AID assignment method.

[0114] When an AP sends a VHT PPDU to a STA, it sets the PAID using the STA's AID information and a K-bit value based on the BSSID. In this case, the STA's AID can be set using any of the following embodiments of the present invention. The AP includes the set PAID information in the preamble of the VHT PPDU and transmits it. In this case, the PAID information can be included in the VHT-SIG-A of the VHT PPDU.

[0115] The following describes an AID assignment method according to various embodiments of the present invention with reference to the accompanying drawings and equations. The AP can assign an AID to each STA using at least one of the following embodiments. Depending on the embodiment, the AP can assign an AID to a VHT STA using the rules described below. Furthermore, the AP can transmit the assigned AID information to terminals associated with the AP. In each embodiment, repeated descriptions of portions identical or corresponding to the previous embodiment will be omitted.

[0116] Equation 2 shows a first embodiment of the AID assignment method according to the present invention.

[0117] [Equation 2]

[0118] AID(8-N+1:8)=bin[(dec(BCB(0:N-1)+dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod 2^N,N]

[0119] Here, N is any integer between 1 and 4.

[0120] According to an embodiment of the present invention, the bits from bit 8-N+1 to bit 8 of the AID can be set according to the rules of Equation 2. In this case, the BCB indicates a partial BSS color or BSS color. The partial BSS color is notified to the STAs associated with the BSS by the AP operating the BSS. According to the embodiment of Equation 2, the predetermined N bits of the AID can be determined using BCB information and BSSID information. The BCB information is a partial BSS color value and represents the value of the least significant N bits of the BSS color. However, the present invention is not limited to this, and the BCB information may represent the value of the most significant N bits of the BSS color. The BSSID information represents a value based on the BSSID of the BSS operated by the AP that assigns the AID. The value based on the BSSID represents the exclusive OR of certain bits of the BSSID. More specifically, the value based on the BSSID represents the exclusive OR of the first predetermined N bits of the BSSID and the second predetermined N bits of the BSSID. According to the embodiment of Equation 2, the first predetermined N bits represent bits from bit 47-N+1 to bit 47, and the second predetermined N bits may represent bits from bit 43-N+1 to bit 43. Hereinafter, in the embodiment of the present invention, a value based on a BSSID for AID assignment will be referred to as a "BSSID-based N-bit value."

[0121] When the AID is assigned as described above, the predetermined bit of the PAID determined according to the embodiment of Equation 1, that is, PAID (8-N+1: 8) may have BSS identification capability. When the PAID has BSS identification capability, the non-traditional terminal is able to determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the PAID information of the received frame. In an embodiment of the present invention, a non-traditional terminal may refer to a terminal that complies with the next-generation wireless LAN standard (ie, IEEE 802.11ax). An intra-BSS frame indicates a frame sent from a terminal belonging to the same BSS, and an inter-BSS frame indicates a frame sent from a terminal belonging to another BSS.

[0122] Non-legacy terminals can use information for identifying the BSS, such as BSS color, partial BSS color, MAC address, etc. to perform BSS intra-frame and BSS inter-frame determination. The partial BSS color can indicate the BCB value of Equation 2. According to an embodiment of the present invention, when the AID is assigned according to a specific rule, the partial BSS color information can be extracted from the predetermined bits of the PAID according to Equation 1. In this case, the predetermined bits of the PAID can indicate the upper N bits of the PAID, that is, PAID (8-N+1:8).

[0123] A non-legacy terminal may perform different operations depending on whether the received frame is an intra-BSS frame. That is, when the received frame is determined to be an intra-BSS frame, the terminal may perform a first operation. Alternatively, when the received frame is determined to be an inter-BSS frame, the terminal may perform a second operation different from the first operation. According to embodiments of the present invention, the first operation and the second operation may be set in various ways.

[0124] According to an embodiment, the terminal may perform channel access based on different thresholds, depending on whether the received frame is an intra-BSS frame. More specifically, when the received frame is determined to be an intra-BSS frame, the terminal accesses the channel based on the first CCA threshold (i.e., a first operation). That is, the terminal performs CCA based on the first CCA threshold, and determines whether the channel is busy based on the result of performing the CCA. On the other hand, when the received frame is determined to be an inter-BSS frame, the terminal accesses the channel based on a second CCA threshold (i.e., a second operation), which is different from the first CCA threshold. That is, the terminal determines whether the channel is busy 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, which is used to determine whether the channel is busy based on the received signal strength between BSS frames. In this case, the second CCA threshold may have a value equal to or higher than the first CCA threshold.

[0125] According to another embodiment, the terminal may set or update different network allocation vectors (NAVs) depending on whether the received frame is an intra-BSS frame. More specifically, when the received frame is determined to be an intra-BSS frame, the terminal sets or updates a first NAV based on the duration information of the corresponding frame (i.e., a first operation). In this case, the first NAV may be an intra-BSS NAV managed to protect intra-BSS frames. On the other hand, when the received frame is determined to be an inter-BSS frame, the terminal sets or updates a second NAV based on the duration information of the frame (i.e., a second operation). In this case, the second NAV may be a basic NAV managed to protect inter-BSS frames.

[0126] According to an embodiment of the present invention, when the 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. When the extracted group ID information is equal to a predetermined value (e.g., 63), the non-legacy terminal can determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the extracted PAID information. More specifically, the terminal performs intra-BSS and inter-BSS frame determination by comparing the extracted PAID information with information for identifying the BSS associated with the terminal. As described later, the information for identifying the BSS associated with the terminal includes the PAID of the terminal according to an embodiment, the BSS color announced by the AP associated with the terminal, and the partial BSS color announced by the AP associated with the terminal. On the other hand, the predetermined value (i.e., 63) of the group ID information indicates that the frame is a downlink frame.

[0127] At the same time, when assigning an AID according to the rule of Equation 2, among the AID candidate values ​​of the corresponding BSS or multiple BSSs, the value of AID (8-N+1:8) that does not comply with the rule of Equation 2 is not used as the AID value. According to an embodiment of the present invention, an unused AID value can be used to indicate a group of STAs. More specifically, an AID value that does not comply with the rule of Equation 2 can be implicitly or explicitly designated as an identifier indicating a group of STAs. The identifier indicating the STA group can be included as a STA-ID value in the user field of the HE-SIG-B of the High Efficiency (HE) Multi-User (MU) PPDU. The STA of the group indicated by the identifier can decode the corresponding resource unit.

[0128] Figure 9 The figure shows a non-traditional element format according to an embodiment of the present invention. The AP may use Figure 9 The element shown in [ ] notifies STAs of partial BSS color information. Non-legacy elements can be included in beacon frames, probe request frames, probe response frames, association request frames, association response frames, reassociation request frames, reassociation response frames, etc. In addition, non-legacy elements can also be sent via frames containing only this element.

[0129] refer to Figure 9 , a non-legacy element may include an "element ID" field, a "length" field, and a "partial BSS color information" field. The "element ID" field indicates the type of the corresponding element (e.g., a "partial BSS color information element"). The "length" field indicates the length information of the corresponding element. The "partial BSS color information" field may include a "partial BSS color bit number for AID" field, a "partial BSS color bits" field, and a reserved field. According to an embodiment, the "partial BSS color information" field may include a "partial BSS color bit number for AID" field and a 4-bit "partial BSS color bits" field.

[0130] The "Number of partial BSS color bits used for AID" field indicates the number N of partial BSS color bits used for AID assignment. Depending on the value of N indicated above, the least significant N bits of the BSS color may be used for AID determination. According to an embodiment, N may indicate any value between 1 and the maximum number of partial BSS color bits (e.g., 4). According to another embodiment, N may also indicate 0 to indicate that partial BSS color is not used in AID assignment. If N indicates 0, the BSS intra / inter frame determination method using the PAID information of the VHTPPDU may not be used. According to an embodiment of the present invention, when 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 may assign the AID according to the method of Equation 2.

[0131] The "Partial BSS Color Bits" field indicates the bit value of the partial BSS color. The "Partial BSS Color Bits" field may indicate the BCB value of Equation 2. Furthermore, when determining an AID according to an embodiment of the present invention, the "Partial BSS Color Bits" field may be represented by the PAID (8-N+1:8) value according to Equation 1. According to an embodiment, the bit value of the partial BSS color may be determined independently of the BSS color. In this manner, the problem of overlapping of the partial BSS color value with the color value of a neighboring BSS may be reduced. According to another embodiment, the bit value of the partial BSS color may be determined depending on the BSS color. In this manner, a recipient of the BSS color information may estimate the partial BSS color bit value based on this. According to an embodiment of the present invention, the "Partial BSS Color Bits" field may be variably determined based on the value of the "Number of Partial BSS Color Bits for AID" field.

[0132] According to an embodiment of the present invention, the partial BSS color can be set by the AP operating the corresponding BSS. The AP notifies the STAs associated with the BSS of the set partial BSS color. If multiple BSSID sets are used, BSSs in the same multiple BSSID sets can use the same partial BSSID color.

[0133] According to another embodiment of the present invention, the AP may change the value of the number N of partial BSS color bits used for AID assignment in the corresponding BSS. If the AID is assigned according to the embodiment of Equation 2, AID (8-N+1:8) has a fixed value in the BSS. Therefore, the larger the number of bits N, the fewer the number of AIDs that can be assigned to the STA. Therefore, when performing AID assignment according to the set value of the number of bits N, the AP may reduce the value of the number of bits N to perform association with a larger number of STAs. For example, in order to associate with a larger number of STAs, the AP may reduce the value of the number of bits N by one. In this case, the remaining bits obtained by subtracting the most significant bit or the least significant bit from the previously used partial BSS color bits can be used as new partial BSS color bits. In addition, the AP may change the value of the partial BSS color bits used in the corresponding BSS. The AP may send Figure 9 to change the number N of partial BSS color bits and / or the partial BSS color bit values ​​used in AID assignment.

[0134] Figure 10 FIGURE 2 illustrates a partial AID calculation process according to an embodiment of the present invention. Figure 10 , Figure 10 dec(AID[0:8]) in (a) (hereinafter referred to as "specific bit information of AID") and Figure 10 dec(BSSID[44:47]XORBSSID[40:43])*2^5 (hereinafter, “information obtained from BSSID”) in (b) is summed in the PAID calculation process according to Equation 1. In this case, in the information obtained from the BSSID, the five bits from B0 to B4 are all 0 by the multiplication operation of 2^5.

[0135] When N is 4 in the AID assignment rule of Equation 2, AID[5:8] is determined as a fixed value in the BSS by the rule of Equation 2. Therefore, a single PAID(8-N+1:8) is determined within the BSS, regardless of the assigned AID value and BSSID value. However, when N is less than 4 in the AID assignment rule of Equation 2, at least some bits of AID[5:8] may be determined as variable values. Therefore, multiple PAID(8-N+1:8) values ​​can be determined within the BSS based on the assigned AID value and BSSID value. For example, when 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 B(8-N+1-1) value depending on the specific bit information of the AID may or may not be rounded. If this ambiguity is not resolved, it may result in the intra-BSS frame being mistakenly determined as an inter-BSS frame.

[0136] When performing BSS intra-frame and inter-BSS frame determination based on the PAID information of the received frame, the terminal can check whether the PAID information extracted from the received frame matches the PAID information related to the BSS associated with the terminal. Here, the PAID information indicates a predetermined bit of the PAID. More specifically, the PAID information can indicate the high N bits of the PAID, that is, PAID (8-N+1:8). When the PAID information extracted from the received frame matches the PAID information related to the BSS associated with the terminal, the terminal determines the received frame as an intra-BSS frame. However, when the PAID information extracted from the received frame does not match the PAID information related to the BSS associated with the terminal, the terminal determines the received frame as an inter-BSS frame.

[0137] At the same time, due to the ambiguity of the above-mentioned PAID value determination, various PAID comparison methods can be used to solve the problem. According to an embodiment, the terminal compares the PAID (8-N+1:8) extracted from the received frame with all possible PAIDs (8-N+1:8) to perform intra-BSS / inter-BSS frame determination. If the PAID (8-N+1:8) extracted from the received frame matches any possible PAID (8-N+1:8) in the BSS associated with the terminal, 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 possible PAID (8-N+1:8) in the BSS associated with the terminal, the terminal determines the received frame as an inter-BSS frame. According to an embodiment of the present invention, intra-BSS frame and inter-BSS frame determination can be performed when the group ID of the received frame is equal to a predetermined value (e.g., 63).

[0138] According to another embodiment, the terminal performs intra / internal BSS authentication by comparing the PAID (8-N+1:8) extracted from the received frame with i) the PAID (8-N+1:8) of the BSS associated with the terminal, ii) PAID' (8-N+1:8) obtained by adding 1 to the B(8-N+1) position of the PAID of the BSS associated with the terminal; and iii) PAID" (8-N+1:8) obtained by subtracting 1 from the B(8-N+1) position of the PAID of the BSS associated with the terminal. Inter-BSS frame determination. If the PAID (8-N+1:8) extracted from the received frame matches any one of i), ii), and iii), 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 i), ii), and iii), the terminal determines the received frame as an inter-BSS frame. According to an embodiment of the present invention, when the group ID of the received frame is equal to a predetermined value (e.g., 63), intra-BSS frame and inter-BSS frame determination can be performed.

[0139] To address the issue caused by the ambiguity in determining the PAID value described above, additional rules may be applied to AID assignment. According to one embodiment, B(8-N+1-1) of the AID may always be set to 0. According to another embodiment, when the value of B(8-N+1-1) of the information obtained from the BSSID is 0, B(8-N+1-1) of the AID may always be set to 0.

[0140] On the other hand, partial BSS colors can be set to the same value in different BSSs. Therefore, if the result of determining the intra / inter BSS frame based on the partial BSS color is different from the result of determining 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 as an inter-BSS frame. In addition, according to an embodiment of the present invention, if 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 met, the terminal can determine the received frame as an inter-BSS frame.

[0141] In a specific embodiment, if a received frame is determined to be an intra-BSS frame based on a partial BSS color but is determined to be an inter-BSS frame based on a MAC address, the terminal may set or update the aforementioned basic NAV. The terminal sets or updates the basic NAV based on the duration field information in the MAC header of the received frame.

[0142] Figure 11The following illustrates the partial AID calculation process according to an embodiment of the present invention in more detail. The AP can set the PAID according to the embodiment of Equation 1, and Figure 11 (a) and (b) of 11 show the corresponding process. Figure 11 As shown in (b), x represents bits 0 to 8 of the AID (ie, AID[0:8]), and y represents (BSSID[44:47] XOR BSSID[40:43])*2^5. z represents the sum of x and y. In addition, Figure 11 (c) shows an assignment rule of bits from bit (8-N+1) to bit 8 (ie, AID[8-N+1:8]) according to Equation 2.

[0143] Will refer to Figure 11 (a) to (c) of 11 describe the process of calculating PAID. Figure 11 When assigning AID according to the rule (c) of Figure 11 According to the rule of (c) of the present invention, the high N bits of x are assigned. According to an embodiment of the present invention, N can be any value between 1 and 4. However, according to another embodiment of the present invention, N is set to 0, so that according to Figure 11 The AID assignment method and the BSS intra / inter frame determination method using PAID of the rule (c) may not be executed. N may be Figure 9 The non-traditional elements described in the above are carried, but the present invention is not limited thereto. Figure 11 The *2^5 operation in (b) sets the lower 5 bits of y to all 0s (i.e., '00000'). z is calculated by adding x and y, and the PAID is calculated by performing a mod 2^9 operation on z. If the number of bits is increased from bit position B8 to bit position B9 when calculating z by adding x and y, the mod operation truncates the increased value.

[0144] According to an embodiment of the present invention, the high N bits of x are composed of a combination of a partial BSS color value and an N-bit value based on the BSSID, such as Figure 11 The AID assignment rule shown in (c) is determined. Therefore, the high N bits of x are values ​​that depend on the BSS. In addition, y is a value that depends on the BSS because it is determined based on the K-bit value of the BSSID. Therefore, the high N bits of the PAID can be values ​​that depend on the BSS. According to an embodiment of the present invention, part of the BSS color can be used as information for BSS identification. Part of the BSS color can indicate Figure 11 BCB[0:N-1] used in the AID assignment rule of (c) According to an embodiment of the present invention, the partial BSS color may be represented by the upper N bits of the PAID. However, according to another embodiment of the present invention, the partial BSS color may indicate the upper N bits of x.

[0145] On the other hand, if the ambiguity in determining intra-BSS frames and inter-BSS frames is not resolved, an intra-BSS frame may be mistakenly determined as an inter-BSS frame. If an intra-BSS frame is mistakenly determined as an inter-BSS frame, the terminal may determine whether the channel is busy based on a second CCA threshold. In this case, the second CCA threshold may be set to a value higher than the first CCA threshold applied to intra-BSS frames. If the terminal performs channel access based on the second CCA threshold, it may interfere with the received packets. In addition, because the AP is sending packets, the AP cannot receive packets sent by the terminal. In this way, the terminal's intra-BSS / inter-frame determination error may interfere with intra-BSS operations.

[0146] Therefore, a method for resolving the ambiguity of intra-BSS frames and determining inter-BSS frames is needed. Hereinafter, methods for determining intra-BSS frames and inter-BSS frames according to various embodiments of the present invention will be described with reference to the accompanying drawings. In each embodiment, it is assumed that the received frame is a VHTPPDU and the group ID is set to 63 (i.e., the frame is a downlink frame).

[0147] Figure 12 The figure illustrates a first embodiment of a method for determining intra-BSS frames and inter-BSS frames according to the present invention. According to an embodiment of the present invention, multiple PAID (8-N+1:8) values ​​can be determined in a BSS based on assigned AID values ​​and BSSID values. Therefore, the terminal can compare the PAID (8-N+1:8) extracted from the received frame with all possible PAIDs (8-N+1:8) in the BSS associated with the terminal to perform intra / inter-BSS frame determination. If the PAID (8-N+1:8) extracted from the received frame matches any possible PAID (8-N+1:8) in the BSS associated with the terminal, 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 possible PAID (8-N+1:8) in the BSS associated with the terminal, the terminal determines the received frame as an inter-BSS frame.

[0148] Figure 12 12(a) and 12(b) illustrate a method of determining whether a received frame is an intra-BSS frame or an inter-BSS frame based on a PAID calculation process of a receiving terminal. Figure 12 (a) shows that Figure 10 and Figure 11 The determination method in the case of increasing the number of digits at B(8-N+1-1) during the PAID calculation process of the terminal shown in FIG. Figure 12 (b) shows that Figure 10 and Figure 11The determination method in the case where the number of bits at B(8-N+1-1) is not increased during the PAID calculation process of the terminal illustrated in FIG.

[0149] First, refer to Figure 12 (a), the terminal receives a wireless frame and extracts PAID information from the received frame (S1210). In this case, the group ID can be extracted together from the received frame, and it is assumed that the group ID is equal to 63. The terminal determines whether the PAID (8-N+1: 8) of the received frame matches any one of the following (S1220). ai) PAID (8-N+1: 8) of the terminal, a-ii) PAID (8-N+1: 8)-1 (8-N+1) of the terminal. Here, 1 (8-N+1) indicates that the value of bit (8-N+1) of PAID is 1. Because Figure 12 In the embodiment (a), the number of bits has been increased during the terminal's PAID calculation process, so PAID' (8-N+1: 8) obtained by subtracting 1 from the terminal's PAID (8-N+1: 8) can exist in the BSS. Therefore, the terminal determines whether the PAID (8-N+1: 8) of the received frame matches any of the above ai) and a-ii). If the PAID (8-N+1: 8) extracted from the received frame matches any of ai) and a-ii), the terminal determines the received frame as 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 as an inter-BSS frame.

[0150] Next, refer to Figure 12 (b), the terminal receives a wireless frame and extracts the PAID information from the received frame (S1260). In this case, the group ID can be extracted together from the received frame, and it is assumed that the group ID is equal to 63. The terminal determines whether the PAID (8-N+1: 8) of the received frame matches any one of the following (S1270). bi) PAID (8-N+1: 8) of the terminal, b-ii) PAID (8-N+1: 8)+1(8-N+1) of the terminal. Here, 1(8-N+1) indicates that the value of bit (8-N+1) of PAID is 1. Because in Figure 12In the embodiment of (b), the number of bits is not increased during the calculation of the terminal's PAID, so the PAID (8-N+1:8) obtained by adding 1 to 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 the above-mentioned bi) and b-ii). If the PAID (8-N+1:8) extracted from the received frame matches any one of bi) and b-ii), the terminal determines the received frame as an intra-BSS frame (S1280). However, if the PAID (8-N+1:8) extracted from the received frame does not match any one of bi) and b-ii), the terminal determines the received frame as an inter-BSS frame (S1282).

[0151] Figure 13 FIG2 illustrates a second embodiment of a method for determining intra-BSS frames and inter-BSS frames according to the present invention. According to the second embodiment of the present invention, a terminal calculates a reference value x' for determining intra / inter-BSS frames using a PAID value of a received frame and a K-bit value based on a BSSID of a BSS associated with the terminal.

[0152] More specifically, the terminal receives a wireless frame and extracts PAID information from the received frame (S1310). In this case, the group ID can be extracted together from the received frame, and it is assumed that the group ID is equal to 63. The terminal calculates a reference value x' using the PAID value of the received frame and K bits of a value based on the BSSID of the BSS associated with the terminal (S1320). In an embodiment of the present invention, the reference value x' can be determined by a combination of the PAID value of the received frame and a K-bit value based on the BSSID of the BSS associated with the terminal. More specifically, it is possible to calculate the reference value x' by extracting the PAID value of the received frame (i.e., in Figure 11 The reference value x' is calculated by subtracting the K-bit value of the BSSID based on the BSS associated with the terminal and the multiplication of 2^5 (ie, y'). Figure 14 A specific embodiment thereof is described. The terminal determines whether the reference value x'(8-N+1:8) matches the AID (8-N+1:8) of the terminal (S1330). If the reference value x'(8-N+1:8) matches the AID (8-N+1:8) of the terminal, the terminal determines the received frame as an intra-BSS frame (S1340). However, if the reference value x'(8-N+1:8) does not match the AID (8-N+1:8) of the terminal, the terminal determines the received frame as an inter-BSS frame (S1342).

[0153] Figure 14 The diagram shows a process of calculating a reference value and a process of calculating a partial AID for BSS intra / inter frame determination according to an embodiment of the present invention. Figure 14 In the embodiment, the definition of each variable is as follows.

[0154] PAID indicates a partial AID extracted from a received frame. PAID can be extracted from VHT-SIG-A1 of a received VHT PPDU.

[0155] -x represents the AID of the intended recipient of the frame (0:8).

[0156] -y represents (BSSID[44:47]XOR BSSID[40:43])*2^5 of the BSS to which the terminal sending the frame belongs.

[0157] -y' represents (BSSID[44:47]XOR BSSID[40:43])*2^5 of the BSS associated with the terminal receiving the frame.

[0158] In other words, y represents the multiplication of 2^5 and a K-bit value based on the BSSID of the BSS associated with the terminal that sent the frame, and y' represents the multiplication of 2^5 and a K-bit value based on the BSSID of the BSS associated with the terminal that received the frame. Figure 14 In the embodiment of , x' represents a 9-bit binary value. A separate bin[x',9] operation can be performed to obtain the value from the binary value according to Figure 14 The embodiment of (a) calculates the value of to obtain the binary number x'.

[0159] first, Figure 14 (a) shows the process of calculating the reference value x' for BSS intra / inter frame determination. The terminal receiving the frame compares the PAID extracted from the received frame with y'. If PAID-y' is less than 0 (ie, case RX1), the terminal sets x' to PAID-y'+2^9. However, if PAID-y' is equal to or greater than 0 (ie, case RX2), the terminal sets x' to PAID-y'. The terminal can perform a similar operation to Figure 13 An embodiment of the BSS intra / inter frame determination.

[0160] Next, Figure 14 (b) shows the process of calculating the PAID by the terminal sending the PPDU. Figure 11 In an embodiment, the PAID may be calculated by (x+y) mod 2^9. Since x and y are 9-bit values, x and y respectively satisfy the following conditions.

[0161] 0<=x<2^9, 0<=y<2^9

[0162] Therefore, x+y satisfies the following conditions.

[0163] 0<=x+y<2^10

[0164] Therefore, according to an embodiment of the present invention, the PAID can be calculated as follows: If x + y is equal to or greater than 2^9 (i.e., case TX1), the PAID is set to x + y - 2^9. However, if x + y is less than 2^9 (i.e., case TX2), the PAID is set to x + y.

[0165] When using the reference value x' according to an embodiment of the present invention, the receiving terminal's intra / inter BSS frame determination process is described as follows. First, if the frame received by the terminal is an intra BSS frame, the receiving terminal determines as follows. When the terminal receives an intra BSS frame, y and y' are determined based on the same BSSID, so that y = y' is satisfied.

[0166] A-1) When the sending terminal calculates the PAID through case Tx1

[0167] According to the equation for case Tx1, PAID-y = x - 2^9. In this case, because x is less than 2^9, PAID-y < 0. Because 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 equation.

[0168] [Equation 3]

[0169] x'=PAID-y'+2^g=PAID-y+2^9=x

[0170] That is, x'=x and x'(8-N+1:8)=x(8-N+1:8). When the AID of each terminal is assigned according to the above-mentioned rules, terminals of the same BSS 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.

[0171] A-2) When the sending terminal calculates the PAID through case Tx2

[0172] According to the equation for case Tx2, PAID-y = x. In this case, because x is equal to or greater than 0, PAID-y >= 0. Because 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 equation.

[0173] [Equation 4]

[0174] x'=PAID-y'=PAID-y=x

[0175] That is, x'=x and x'(8-N+1:8)=x(8-N+1:8). When the AID of each terminal is assigned according to the above rules, terminals in the same BSS 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.

[0176] Next, if the frame received by the terminal is an inter-BSS frame, the receiving terminal determines as follows: When the terminal receives the inter-BSS frame, since y and y' are determined based on different BSSIDs, there is a high probability that y and y' represent different values.

[0177] B-1) When the transmitting terminal calculates PAID through case Tx1 and the receiving terminal calculates x′ through case RX1

[0178] In this case, x′ satisfies the following equation.

[0179] [Equation 5]

[0180] x'=PAID-y'+2^9=x+y-2^9-y'+2^9=x+y-y'

[0181] Therefore, when y and y' are different, x' and x are different. Because the lower 5 bits of y and y' are all 0, x'(5:8) and x(5:8) are different. When N is set to a value of 4 or less, x'(8-N+1:8) indicates at least some bits of x'(5:8) and x(8-N+1:8) indicates at least some bits of x(5:8). Therefore, 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. Therefore, the receiving terminal has a high probability of determining that the frame is an inter-BSS frame.

[0182] B-2) When the transmitting terminal calculates PAID through case Tx2 and the receiving terminal calculates x′ through case RX1

[0183] In this case, x′ satisfies the following equation.

[0184] [Equation 6]

[0185] X'=PAID-y'+2^9=X+y-y'+2^9

[0186] In this case, since -2^9 < y - y' < 2^9 is satisfied, when y and y' are different, x' and x are different. As described above, when 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. Therefore, the receiving terminal has a high probability of determining that the frame is an inter-BSS frame.

[0187] B-3) When the transmitting terminal calculates PAID through case Tx1 and the receiving terminal calculates x' through case RX2

[0188] In this case, x' satisfies the following equation.

[0189] [Equation 7]

[0190] x′ = PAID - y' = x + y - 2^9 - y’ = x + y - y' - 2^9

[0191] In this case, since -2^9 < y - y' < 2^9 is satisfied, when y and y' are different, x' and x are different. As described above, when 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, there is a high probability that x'(8 - N + 1:8) is different from the AID(8 - N + 1:8) of the receiving terminal. Therefore, the receiving terminal has a high probability of determining that the frame is an inter-BSS frame.

[0192] B-4) When the transmitting terminal calculates PAID through case Tx2 and the receiving terminal calculates x' through case RX2

[0193] In this case, x' satisfies the following equation.

[0194] [Equation 8]

[0195] x' = PAID - y' = x + y - y' <00><000493>When y and y' are different, x' and x are different. As described above, when 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. Therefore, the receiving terminal has a high probability of determining that the frame is an inter-BSS frame.

[0197] At the same time, 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 probability that an inter-BSS frame is mis-determined as an intra-BSS frame and the probability that an intra-BSS frame is mis-determined as an inter-BSS frame. However, according to Figure 13In the determination method of the embodiment, although there is a possibility that an inter-BSS frame is erroneously determined as an intra-BSS frame, there is no case where an intra-BSS frame is erroneously determined as an inter-BSS frame.

[0198] According to another embodiment of the present invention, a terminal may compare a value calculated using x'(8-N+1:8) and y'(8-N+1:8) with a partial BSS color value (i.e., BCB information) to perform BSS intra / inter frame determination. More specifically, when 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 advertised to the terminal. If they match, the terminal determines the received frame as an intra-BSS frame. If they do not match, the terminal determines the received frame as an inter-BSS frame. On the other hand, when the value of x'(8-N+1:8)-y'(8-N+1:8) is equal to or greater than 0, the terminal determines whether the value of x'(8-N+1:8)-y'(8-N+1:8) matches the partial BSS color value advertised to the terminal. If they match, the terminal determines the received frame as an intra-BSS frame. If they do not match, the terminal determines the received frame as an inter-BSS frame.

[0199] When the terminal has verified that there is ambiguity in the determination of the PAID value, Figures 12 to 14 The determination method of an embodiment may be performed. As an embodiment, if the terminal has verified that there is no ambiguity in the PAID determination, the terminal may compare the PAID (8-N+1:8) of the received frame with the PAID (8-N+1:8) of the terminal to perform BSS intra / inter frame determination. That is, if the PAID (8-N+1:8) extracted from the received frame matches the PAID (8-N+1:8) of the terminal, 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 PAID (8-N+1:8) of the terminal, the terminal determines the received frame as an inter-BSS frame.

[0200] According to various embodiments, the terminal is able to identify whether there is ambiguity in the determination of the PAID value. According to an embodiment, if y(5:8-N+1-1) is all 0, the terminal can determine that there is ambiguity, and if not, the terminal can determine that there is no ambiguity. According to another embodiment, if N=4, the terminal can determine that there is no ambiguity, and if N is any one of 1 to 3, the terminal can determine that there is ambiguity. Here, N represents the number of partial BSS color bits used for AID assignment and the number of bits of BSSID information. According to yet another embodiment, the terminal can determine that there is ambiguity by Figure 15 and Figure 16The method described in identifies whether there is ambiguity in the determination of the PAID value.

[0201] Figure 15 FIGURE 1 illustrates a non-traditional element format according to another embodiment of the present invention. Figure 15 In the fields for non-traditional elements in the Figure 9 The fields for the non-traditional elements described in the same section are repeated.

[0202] refer to Figure 15 The non-legacy element may include an "element ID" field, a "length" field, and a "partial BSS color information" field. Furthermore, the "partial BSS color information" field may include a "partial BSS color bit count used for AID" field, a "partial BSS color bits" field, and an "ambiguity" field. According to an embodiment, the "partial BSS color information" field includes a 3-bit "partial BSS color bit count used for AID" field, a 4-bit "partial BSS color bits" field, and a 1-bit "ambiguity" field. The "ambiguity" field signals, via a flag value, whether ambiguity exists in determining the PAID value.

[0203] Figure 16 The diagram illustrates a method for signaling information about the number of partial BSS color bits and ambiguity information according to another embodiment of the present invention. According to an embodiment of the present invention, the "Partial BSS Color Bits for AID" field of a non-legacy element can signal whether the above-mentioned ambiguity can exist. More specifically, the "Partial BSS Color Bits for AID" field can indicate the number of partial BSS color bits used for AID assignment and whether ambiguity can exist using predetermined indexes. For example, indices 1 to 4 can respectively indicate that the number of partial BSS color bits used for AID assignment is 1 to 4, and ambiguity does not exist. On the other hand, when the number of partial BSS color bits used for AID assignment is 4, ambiguity in determining the PAID value can exist. Therefore, indices 5 to 7 can further indicate that the number of partial BSS color bits used for AID assignment is 1 to 3, and ambiguity can exist.

[0204] Figure 17 FIG. 2 shows a second embodiment of an AID assignment method and a non-legacy element format according to the present invention. Figure 17 (a) shows an AID assignment method according to another embodiment of the present invention, and Figure 17 (b) shows the corresponding non-traditional element format.

[0205] First, refer to Figure 17 (a), the second embodiment of the AID assignment method according to the present invention can be expressed as the following Equation 9.

[0206] [Equation 9]

[0207] AID(8-N+1:8)=bin[dec(BCB(0:N-1)+dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod 2^N,N]

[0208] Here, N is 4.

[0209] The second embodiment of the AID assignment method according to the present invention is the same as the first embodiment of the AID assignment method described with reference to Equation 2, wherein N is limited to 4. More specifically, the predetermined N bits of the AID are determined using the value of the least significant N bits of the BSS color (i.e., the partial BSS color value) and the N-bit value based on the BSSID. That is, the predetermined N bits of the AID are determined by applying a modulo operation to the value of the sum of the least significant N bits of the partial BSS color and the N-bit value based on the BSSID. In this case, the predetermined N bits of the AID are bits from bit 8-N+1 to bit 8 of the AID, and N is set to 4. According to the above Figure 1 According to the PAID setting rule, the number of significant bits K of the BSSID value used to set the PAID is set to 4. According to an embodiment of the present invention, by setting N to 4 in the AID assignment rule, ambiguity in determining the PAID value can be eliminated, which is the same as the K value used to set the PAID.

[0210] Referring to 17(b), the "Partial BSS Color Information" field of the non-legacy element may include 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 assignment rule in which partial BSS color bits are used. If this field is set to 1, an N-bit (where N is 4) partial BSS color value is used for AID assignment. However, if this field is set to 0, the partial BSS color is not used for AID assignment. According to Figure 17 In the embodiment, the number N of partial BSS color bits used for AID assignment is fixed. Therefore, the non-legacy element can indicate whether the partial BSS color is used for AID assignment via a 1-bit "Partial BSS Color Bit Indication" field.

[0211] 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 information of the "Partial BSS Color Bits" field is signaled through the "Partial BSS Color Information" field, a terminal receiving the non-legacy element can recognize that the partial BSS color value is used for AID assignment.

[0212] Figure 18 FIG3 shows a third embodiment of the AID assignment method according to the present invention. Figure 18 , the third embodiment of the AID assignment method according to the present invention can be expressed as the following Equation 10.

[0213] [Equation 10]

[0214] if(dec(BCB[0:N-1])-dec(BSSID[47-N+1:47]XOR BSSID[43-N+1:43]))<0

[0215] AID[8-N+1:8]=bin[(2^N+dec(BCB[0:N-1])-dec(BSSID[47-N+1:47]XOR BSSID[43-N+1:43])), N]

[0216] else / / (dec(BCB[0:N-1])-dec(BSSID[47-N+1:47]XOR BSSID[43-N+1:43]))>=0

[0217] AID[8-N+1:8]=bin[(dec(BCB[0:N-1])-dec(BSSID[47-N+1:47]XOR BSSID[43-N+1:43])),N]

[0218] Here, N is any integer between 1 and 4.

[0219] According to a third embodiment of the present invention, the bits from bit 8-N+1 to bit 8 of the AID can be set according to the rule of equation 10. According to the embodiment of equation 10, the predetermined N bits of the AID can be determined based on the value obtained by subtracting the BSSID information from the BCB information. In this case, the predetermined N bits of the AID are the bits from bit 8-N+1 to bit 8 of the AID. More specifically, the predetermined N bits of the AID are determined by subtracting the N-bit value based on the BSSID from the value of the least significant N bits of the BSS color (i.e., the partial BSS color value). The N-bit value based on the BSSID indicates the exclusive OR of the first predetermined N bits of the BSSID and the second predetermined N bits of the BSSID. In the embodiment of equation 10, the first predetermined N bits can indicate the bits from bit 47-N+1 to bit 47, and the second predetermined N bits can indicate the bits from bit 43-N+1 to bit 43.

[0220] If the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value is less than 0, the predetermined N bits of the AID are determined by adding 2^N to the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value. However, if the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value is equal to or greater than 0, the predetermined N bits of the AID are determined by the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value.

[0221] When the AID is assigned according to the rule of Equation 10, the predetermined N bits of the AID and the N bits of the PAID corresponding thereto may have BSS identification capabilities. Therefore, when the received frame is a VHTPPDU (and the group ID extracted from the received frame is equal to 63), the terminal can perform BSS intra-frame and BSS inter-frame determination by comparing the high N bits of the PAID extracted from the received frame with the partial BSS color announced to the terminal. If the high N bits of the PAID match the partial BSS color announced to the terminal, the terminal determines the received frame as an intra-BSS frame. However, if the high N bits of the PAID do not match the partial BSS color announced to the terminal, the terminal determines the received frame as an inter-BSS frame.

[0222] Figure 19 FIG4 shows a fourth embodiment of the AID assignment method according to the present invention. Figure 18 , the fourth embodiment of the AID assignment method according to the present invention can be expressed as the following Equation 11.

[0223] [Equation 11]

[0224] AID[5:5+N-1]=bin[(dec(BCB[0:N-1])+dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]))mod2^N,N]

[0225] Here, N is any integer between 1 and 4.

[0226] According to a fourth embodiment of the present invention, the bits from bit 5 to bit 5+N-1 of the AID can be set by the rule of equation 11. According to the embodiment of equation 11, the predetermined N bits of the AID are determined by applying a modulo operation to the value of the least significant N bits of the BSS color (i.e., the partial BSS color value) and the value of the sum of the N-bit values ​​based on the BSSID. In this case, the predetermined N bits of the AID are the bits 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 predetermined N bits of the BSSID and the second predetermined N bits of the BSSID. In the embodiment of equation 11, the first predetermined N bits can indicate the bits from bit 44 to bit 44+N-1, and the second predetermined N bits can indicate the bits from bit 40 to bit 40+N-1.

[0227] As referenced above Figure 11 As described above, during 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 the AID are set according to the rule of Equation 11, PAID (5:5+N-1) is set to a fixed value in the BSS. Therefore, when the AID is assigned according to the rule of Equation 11, ambiguity in the PAID value determination can be prevented. Moreover, the predetermined bits of the PAID, i.e., PAID (5:5+N-1), can have BSS identification capabilities. Therefore, when the received frame is a VHT PPDU (and the group ID extracted from the received frame is equal to 63), the terminal can perform intra-BSS frame and inter-BSS frame determination by comparing PAID (5:5+N) of the PAID extracted from the received frame with PAID (5:5+N-1) of the BSS to which the terminal is associated. 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.

[0228] Figure 20 and 21 FIG5 shows a fifth embodiment of the AID assignment method according to the present invention. Figure 20 , the fifth embodiment of the AID assignment method according to the present invention can be expressed as the following Equation 12.

[0229] [Equation 12]

[0230] AID[5:5+N-1]=bin[(dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]))mod 2^N,N]

[0231] Here, N is any integer between 1 and 4.

[0232] According to a fifth embodiment of the present invention, the bits from bit 5 to bit 5+N-1 of the AID can be set according to the rule of equation 12. According to the embodiment of equation 12, the predetermined N bits of the AID are determined based on the value obtained by subtracting the BSSID information from the BCB information. More specifically, the predetermined N bits of the AID are determined by applying a modulo operation to the value obtained by subtracting the N-bit value based on the BSSID from the value of the least significant N bits of the BSS color (i.e., the partial BSS color value). In this case, the predetermined N bits of the AID are the bits 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 predetermined N bits of the BSSID and the second predetermined N bits of the BSSID. In the embodiment of equation 12, the first predetermined N bits can indicate the bits from bit 44 to bit 44+N-1, and the second predetermined N bits can indicate the bits from bit 40 to bit 40+N-1.

[0233] The fifth embodiment of the AID assignment method according to the present invention can also be as follows Figure 21 is expressed as shown in Equation 13 below.

[0234] [Equation 13]

[0235] if(dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]))<0

[0236] AID[5:5+N-1]=bin[(2^N+dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1])),N]

[0237] else / / (dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]))>=0

[0238] AID[5:5+N-1]=bin[(dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1])),N]

[0239] Here, N is any integer between 1 and 4.

[0240] Referring to Equation 13, if the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value is less than 0, the predetermined N bits of the AID are determined by adding 2^N to the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value. However, if the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value is equal to or greater than 0, the predetermined N bits of the AID are determined by subtracting the N-bit value based on the BSSID from the partial BSS color value.

[0241] As referenced above Figure 11 As described above, during the PAID calculation process, the lower five 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 the AID are set according to the rules of Equations 12 and 13, PAID[5:5+N-1] is set to a fixed value in the BSS. Therefore, when the AID is assigned according to the rules of Equations 12 and 13, ambiguity in PAID value determination can be avoided.

[0242] In addition, if the AID is assigned according to the rules of equations 12 and 13, when the PAID is set according to the embodiment of equation 1, the K-bit value based on the BSSID (ie, Figure 11 At least a portion of the y in the PAID is offset by an N-bit value based on the BSSID. Therefore, the predetermined bits of the PAID (i.e., PAID[5:5+N-1]) represent the partial BSS color value announced to the intended recipient of the frame. Therefore, when the received frame is a VHT PPDU (and the group ID extracted from the received frame is equal to 63), the terminal can perform intra-BSS and inter-BSS frame determination by comparing the predetermined bits of the PAID extracted from the received frame with the partial BSS color announced to the terminal. If the predetermined bits of the PAID match the partial BSS color announced to the terminal, the terminal determines the received frame as an intra-BSS frame. However, if the predetermined bits of the PAID do not match the partial BSS color announced to the terminal, the terminal determines the received frame as an inter-BSS frame.

[0243] Hereinafter, the reason why the predetermined bits of the PAID (i.e., PAID[5:5+N-1]) represent the partial BSS color value when using the fifth embodiment of the AID assignment method according to the present invention will be described in more detail. If the received frame is a VHTPPDU and the frame is a downlink single-user (SU) frame, the PAID extracted from the frame is determined according to Equation 1. In this case, AID[0:8] is expressed as Equation 14 when it is divided into the lower 5 bits (i.e., AID[0:4]), the next N bits (i.e., AID[5:5+N-1]), and the remaining bits (i.e., AID[5+N:8]).

[0244] [Equation 14]

[0245] PAID=(dec(AID[0:4]+AID[5:5+N-1]*2^5+AID[5+N:8]*2^(5+N))+dec(BSSID[44:47]XOR BSSID[40:43])*2^5)mod2^9

[0246] (Case a) When dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XORBSSID[40:40+N-1]))<0 hour

[0247] Because 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 as follows according to the if condition of Equation 13.

[0248] [Equation 15]

[0249] AID[5:5+N-1]=bin[(2^N+dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1])),N]

[0250] (Case a-1) When N is not 4

[0251] Substituting Equation 15 into Equation 14 yields the following equation.

[0252] [Equation 16]

[0253] PAID=(dec(AID[0:4])+(2^N+dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XORBSSID[40:40+N-1]))*2 ^5+dec(AID[5+N:8])*2^(5+N)+dec(BSSID[44:44+N-1]XORBSSID[40:40+N-1]+(BSSID[44+N:47]XOR BSSID[40+N:43])*2^N)*2^5)mod 2^9

[0254] Here, a portion of the value based on the BSSID, ie, dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]) is offset (ie, deleted) and the equation can be rearranged as follows.

[0255] [Equation 17]

[0256] PAID=(dec(AID[0:4])+2^(5+N)+dec(BCB[0:N-1])*2^5+dec(AID[5+N:8])*2^(5+N)+dec((BSSID[44+N:47]XOR BSSID[40+N:43])*2^(5+N))mod 2^9

[0257] 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] is equal to BCB[0:N-1].

[0258] (Case a-2) When N is 4

[0259] When N is 4, dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]) of Equation 15 is the same as dec(BSSID[44:47]XOR BSSID[40:43]) of Equation 14. Therefore, substituting Equation 15 into Equation 14 yields the following equation.

[0260] [Equation 18]

[0261] PAID=(dec(AID[0:4])+(2^N+dec(BCB[0:N-1]))*2^5+dec(AID[5+N:8])*2^(5+N)))mod 2^9=(dec(AID[0:4])+2^(5+N)+dec(BCB[0:N-1])*2^5+dec(AID[5+N:8])*2^(5+N)))mod 2^9

[0262] Referring to Equation 18, the only factor that affects PAID[5:5+N-1] is dec(BCB[0:N-1]*2^5). Therefore, PAID[5:5+N-1] is equal to BCB[0:N-1].

[0263] (Case b) When dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]))> =0 o'clock

[0264] Because 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 as follows according to the else condition of Equation 13.

[0265] [Equation 19]

[0266] AID[5:5+N-1]=bin[(dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1])),N]

[0267] (Case b-1) When N is not 4

[0268] Substituting Equation 19 into Equation 14 yields the following equation.

[0269] [Equation 20]

[0270] PAID=(dec(AID[0:4])+(dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]))*2^5+dec(AID[5+N:8])*2^(5+N)+dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]+(BSSID[44+N:47]XOR BSSID[40+N:43])*2^N)*2^5)mod 2^9

[0271] Here, a portion of the value based on the BSSID, ie, dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1]) is offset (ie, deleted) and the equation can be arranged as follows

[0272] [Equation 21]

[0273] PAID=(dec(AID[0:4])+dec(BCB[0:N-1])*2^5+dec(AID[5+N:8])*2^(5+N)+dec((BSSID[44+N:47]XOR BSSID[40+N:43])*2^(5+N))mod 2^9

[0274] 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] is equal to BCB[0:N-1].

[0275] (Case a-2) When N is 4

[0276] When N is 4, dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]) of Equation 19 is the same as dec(BSSID[44:47] XOR BSSID[40:43]) of Equation 14. Therefore, substituting Equation 19 into Equation 14 yields the following equation.

[0277] [Equation 22]

[0278] PAID=(dec(AID[0:4])+(dec(BCB[0:N-1]))*2^5+dec(AID[6+N:8])*2^(5+N)))mod 2^9

[0279] Referring to Equation 22, the only factor that affects PAID[5:5+N-1] is dec(BCB[0:N-1]*2^5). Therefore, PAID[5:5+N-1] is equal to BCB[0:N-1].

[0280] As described above, in all cases, predetermined bits of the PAID, ie, PAID[5:5+N-1], have the same value as a partial BSS color value, ie, BCB[0:N]-1].

[0281] Figure 22 FIG3 illustrates a third embodiment of a method for determining a BSS intra-frame and a BSS inter-frame according to the present invention. Figure 20 and Figure 21 When assigning an AID in the fifth embodiment shown in Figure 22 The intra-BSS frame and inter-BSS frame determination method shown in can be used.

[0282] First, the terminal receives a radio frame and extracts the group ID and PAID information from the received frame (S2210). If the received frame is a VHT PPDU, the RXVECTOR parameter of the frame includes the group ID and PAID. Therefore, if the received frame is a VHT PPDU, the terminal extracts the group ID and PAID information from the preamble of the VHT PPDU.

[0283] Next, the terminal checks which information the extracted group ID represents (S2220). More specifically, the terminal checks whether the extracted group ID information is equal to 0 or 63. As described above, Figure 8 In the embodiment described above, group ID 0 may indicate that the frame is an uplink frame. In addition, group ID 63 may indicate that the frame is a downlink frame. That is, the terminal can identify whether the frame is an uplink frame or a downlink frame through the extracted group ID information.

[0284] If the extracted group ID information is equal to 0 (i.e., indicating an uplink frame), the terminal checks whether the PAID extracted from the frame matches a specific bit value of the BSSID of the BSS associated with the terminal (S2230). In this case, the specific bit value of the BSSID may be BSSID [39:47]. As described above with reference to Figure 8 As described above, since the PAID is set to BSSID[39:47] in the case of an uplink frame, the terminal can determine whether the frame is an intra-BSS frame or an inter-BSS frame based on whether the PAID of the received frame matches the BSSID[39:47] 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).

[0285] Meanwhile, if the extracted group ID information is equal to 63 (i.e., indicating a downlink frame), the terminal checks whether the PAID information extracted from the frame matches the partial BSS color announced to the terminal (S2240). In this case, the PAID information indicates a predetermined bit of the PAID. Figure 22In the embodiment, the predetermined bits of the PAID indicate PAID[5:5+N-1]. Furthermore, the partial BSS color advertised to the terminal indicates the partial BSS color advertised by the AP associated with the terminal. If an AID is assigned according to the fifth embodiment of the present invention, when setting the PAID, at least a portion of the K-bit value based on the BSSID is offset by the N-bit value based on the BSSID. Therefore, the predetermined bits of the PAID (i.e., PAID[5:5+N-1]) indicate the partial BSS color advertised to the intended recipient of the frame. Therefore, the terminal can determine whether a received frame is an intra-BSS frame or an inter-BSS frame based on whether the predetermined bits of the PAID of the received frame match the partial BSS color advertised to the terminal. If the predetermined bits of the PAID match the partial BSS color advertised to the terminal, the terminal determines the received frame as an intra-BSS frame (S2242). However, if the predetermined bits of the PAID do not match the partial BSS color advertised to the terminal, the terminal determines the received frame as an inter-BSS frame (S2244).

[0286] According to an embodiment of the present invention, the intra-BSS frame method and the inter-BSS frame method when the extracted group ID information is equal to 63 can be performed only when the value 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, the intra-BSS frame and inter-BSS frame determination methods when the extracted group ID information is equal to 63 can be performed only when 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 assignment rule in which partial BSS color bits are used is applied.

[0287] Figure 23 FIGURE 1 shows a non-traditional element format according to another embodiment of the present invention. Figure 23 Among the fields of non-traditional elements in the embodiment, repeated descriptions of the parts that are the same as the fields of non-traditional elements described in the above embodiments will be omitted.

[0288] The operation of the HE STA (i.e., non-legacy terminal) of the HE BSS can be controlled by the HT operation element, the VHT operation element, the HE operation element (i.e., non-legacy element), etc. As described above, the non-legacy element can be included in the beacon frame, the probe request frame, the probe response frame, the association request frame, the association response frame, the reassociation request frame, the reassociation response frame, etc. In addition, the non-legacy element can also be transmitted via a frame containing only the element. Figure 23The non-legacy element may include an "element ID" field, a "length" field, and a "HE operation parameter" field. In addition, the "HE operation parameter" field may include a "BSS color" field and a "partial BSS color length" field.

[0289] The "BSS Color" field indicates a BSS color value. The BSS Color indicates the BSS color of the BSS operated by the AP that sent this element. Alternatively, the BSS Color may indicate the BSS color of the BSS associated with the STA that sent this element. The "BSS Color" field has a length of 6 bits and may represent an unsigned integer value. Depending on the embodiment, when the value of the "BSS Color" field is not 0, it may indicate the BSS color, and when the value of the "BSS Color" field is 0, it may indicate that the BSS color is not set for the corresponding BSS.

[0290] The "Partial BSS Color Length" field may include information related to BSS intra / inter frame determination for the PAID using a VHT PPDU. For example, the "Partial BSS Color Length" field may indicate the number of bits, N, used for the partial BSS color assigned by the AID. The "Partial BSS Color Length" field may perform the same function as the "Number of Partial BSS Color Bits for AID" field described above. The "Partial BSS Color Length" field may have a length of 3 bits, but the present invention is not limited thereto.

[0291] Figure 24 FIG6 is a diagram showing a sixth embodiment of the AID assignment method according to the present invention. Figure 24 , the sixth embodiment of the AID assignment method according to the present invention can be expressed as in the following Equation 23.

[0292] [Equation 23]

[0293] AID(8-N+1:8)=bin[(dec(BCB(0:N-1))-dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod 2^N,N]

[0294] Here, N is 4.

[0295] According to a sixth embodiment of the present invention, the bits from bit 8-N+1 to bit 8 of the AID can be set according to the rule of Equation 23. According to the embodiment of Equation 23, the predetermined N bits of the AID can be determined based on the value obtained by subtracting the BSSID information from the BCB information. More specifically, the predetermined N bits of the AID are determined by applying a modulo operation to the value obtained by subtracting the N-bit value based on the BSSID from the value of the least significant N bits of the BSS color (i.e., the partial BSS color value). In this case, the predetermined N bits of the AID are the bits from bit 8-N+1 to bit 8 of the AID. The N-bit value based on the BSSID indicates the exclusive OR of the first predetermined N bits of the BSSID and the second predetermined N bits of the BSSID. In the embodiment of Equation 23, the first predetermined N bits can indicate the bits from bit 47-N+1 to bit 47, and the second predetermined N bits can indicate the bits from bit 43-N+1 to bit 43.

[0296] As referenced above Figure 11 As described above, during 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 the AID are set according to the rule of Equation 23, PAID[5:8] is set to a fixed value in the BSS. Therefore, when the AID is assigned according to the rule of Equation 23, ambiguity in determining the PAID value can be avoided.

[0297] In addition, if the AID is allocated according to the rule of Equation 23, when the PAID is set according to the embodiment of Equation 1, the K-bit value based on the BSSID (ie, Figure 11 y in) is offset by N bits based on the BSSID. Therefore, the predetermined bits of the PAID (i.e., PAID[8-N+1:8]) represent the partial BSS color value announced to the intended recipient of the frame. Therefore, when the received frame is a VHTPPDU (and the group ID extracted from the received frame is equal to 63), the terminal can perform intra-BSS and inter-BSS frame determination by comparing the predetermined bits of the PAID extracted from the received frame with the partial BSS color announced to the terminal. In this case, the predetermined bits of the PAID are the values ​​of the predetermined 4 bits of the PAID, i.e., the values ​​of PAID[5:8]. If the predetermined bits of the PAID match the partial BSS color announced to the terminal, the terminal determines the received frame as an intra-BSS frame. However, if the predetermined bits of the PAID do not match the partial BSS color announced to the terminal, the terminal determines the received frame as an inter-BSS frame.

[0298] According to an embodiment of the present invention, since predetermined bits of the PAID represent a partial BSS color value, a terminal receiving a frame can perform intra-BSS and inter-BSS frame determination by using PAID information without obtaining other information or performing other calculations.

[0299] Figure 25 FIGURE 1 shows a non-traditional element format according to another embodiment of the present invention. Figure 25 In the fields of non-traditional elements in , repeated descriptions of the parts that are the same as the fields of non-traditional elements described in the above embodiments will be omitted.

[0300] refer to Figure 25 The non-legacy element may include an "element ID" field, a "length" field, and a "HE operation parameter" field. Furthermore, the "HE operation parameter" field may include a "BSS color" field and a "partial BSS color indication" field. According to an embodiment, the "HE operation parameter" field of the non-legacy element may include a 6-bit "BSS color" field and a 1-bit "partial BSS color indication" field.

[0301] The "BSS Color" field indicates the Figure 23 The "Partial BSS Color Bit Indication" field indicates whether the corresponding BSS applies an AID assignment rule in which a partial BSS color bit is used. If this field is set to 1, an N-bit (where N is 4) partial BSS color value is used for AID assignment. However, if this field is set to 0, the partial BSS color is not used for AID assignment. In addition, the "Partial BSS Color Bit Indication" field may indicate whether an intra / inter BSS frame determination method using PAID information of a VHT PPDU is used. According to Figure 24 In the embodiment, the number of bits N of the partial BSS color used for AID assignment is fixed. Therefore, the non-legacy element can indicate whether the partial BSS color is used for AID assignment through a 1-bit "Partial BSS Color Bit Indication" field.

[0302] Figure 26 FIG. 7 shows a seventh embodiment of the AID assignment method according to the present invention. Figure 26 (a) shows the AID assignment method when N is not 4. Figure 26 (b) shows an AID assignment method when N is 4. Here, N represents the number of partial BSS color bits used for AID assignment.

[0303] First, refer to Figure 26 (a), when N is not 4, the seventh embodiment of the AID assignment method according to the present invention can be expressed as the following Equation 24.

[0304] [Equation 24]

[0305] AID[5:8]=bin[(dec(BCB[0:N-1])*2 4-N +dec(A[0:3-N])-dec(BSSID[44:47]XORBSSID[40:43]))mod 2 4 , 4]

[0306] Here, A[0:3-N] is an arbitrary (3-N+1)-bit binary number.

[0307] Next, refer to Figure 26 (b), when N is 4, the seventh embodiment of the AID assignment method according to the present invention can be expressed as in the following Equation 25.

[0308] [Equation 25]

[0309] AID[5:8]=bin[(dec(BCB[0:3])-dec(BSSID[44:47]XOR BSSID[40:43]))mod2 4 , 4]

[0310] Referring to Equations 24 and 25, the bits from bit 5 to bit 8 of the AID can be set according to the seventh embodiment of the AID assignment method of the present invention. According to the seventh embodiment of the present invention, the bits from bit 5 to bit 8 of the AID can be determined based on the value obtained by subtracting the BSSID information from the value based on the BCB information. In this case, the BCB information indicates a partial BSS color, and the BSSID information indicates an N-bit value based on the BSSID. More specifically, the N-bit value based on the BSSID can be an exclusive OR of the bit values ​​from bits 44 to 47 of the BSSID and the bit values ​​from bits 40 to 43 of the BSSID.

[0311] If the AID is assigned according to the rules of Equation 24 and Equation 25, when the PAID is set according to the embodiment of Equation 1, the K-bit value based on the BSSID (ie, Figure 11 The y in ( ) is offset by an N-bit value based on the BSSID. Therefore, the predetermined bits of the PAID (i.e., PAID[8-N+1:8]) represent the partial BSS color value advertised to the intended recipient of the frame. Therefore, when the received frame is a VHT PPDU (and the group ID extracted from the received frame is equal to 63), the terminal can perform intra-BSS and inter-BSS frame determination by comparing the predetermined bits of the PAID extracted from the received frame with the partial BSS color advertised to the terminal.

[0312] Hereinafter, the reason why the predetermined bits of the PAID (i.e., PAID[8-N+1:8]) represent the partial BSS color value (i.e., BCB[0:N-1]) when the seventh embodiment of the AID assignment method according to the present invention is used will be described in more detail. First, referring to Equation 1, PAID[5:8] is determined according to the following equation.

[0313] [Equation 26]

[0314] PAID[5:8]=(dec(AID[5:8])+dec(BSSID[44:47]XOR BSSID[40:43]))mod 2^4

[0315] [Case A] When N is not 4

[0316] When N is not 4, AID[5:8] can be set by the rule of Equation 24. Referring to Equation 24, due to A[0:3-N], AID[5:8] is determined as a variable value. The upper N bits of AID[5:8] are determined based on BCB[0:N-1]N] to represent the variable value.

[0317] (Case A-1) When (dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])-dec(BSSID[44:47]]XOR BSSID[40:43]))>=0

[0318] Substituting Equation 24 into Equation 26 yields the following equation.

[0319] [Equation 27]

[0320] PAID[5:8]=((dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])-dec(BSSID[44:47]XOR BSSID[40:43]))+dec(BSSID[44:47]XOR BSSID[40:43]))mod 2^4

[0321] =(dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N]))mod 2^4

[0322] =dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])

[0323] 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] is equal to BCB[0:N-1].

[0324] (Case A-2) When (dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])-dec(BSSID[44:47]] XOR BSSID[40:43]))<0

[0325] Substituting Equation 24 into Equation 26 yields the following equation.

[0326] [Equation 28]

[0327] PAID[5:8]=((2^4+dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])-dec(BSSID[44:47]XOR BSSID[40:43]))+dec(BSSID[44:47]XOR BSSID[40:43]))mod 2^4

[0328] =(2^4+dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N]))mod 2^4

[0329] =dec(BCB[0:N-1])*2^(4-N)+dec(A[0:3-N])

[0330] 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] is equal to BCB[0:N-1].

[0331] [Case B] When N is 4

[0332] When N is 4, AID[5:8] can be set by the rule of Equation 25.

[0333] [Case B-1] When dec(BCB[0:3])-dec(BSSID[44:47]XOR BSSID[40:43])≥=0

[0334] Substituting Equation 25 into Equation 26 yields the following equation.

[0335] [Equation 29]

[0336] PAID[5:8]=(dec(BCB[0:3])-dec(BSSID[44:47]XOR BSSID[40:43])+dec(BSSID[44:47]XOR BSSID[40:43]))mod2^4

[0337] =(dec(BCB[0:3]))mod2^4

[0338] =dec(BCB[0:3])

[0339] Referring to Equation 29, PAID[8-N+1:8] is equal to BCB[0:N-1] (where N is 4).

[0340] [Case B-2] When dec(BCB[0:3])-dec(BSSID[44:47]XOR BSSID[40:43])<0

[0341] Substituting Equation 25 into Equation 26 yields the following equation.

[0342] [Equation 30]

[0343] PAID[5:8]=(2^4+dec(BCB[0:3])-dec(BSSID[44:47]XOR BSSID[40:43])+dec(BSSID[44:47]XOR BSSID[40:43]))mod 2^4

[0344] =(2^4+dec(BCB[0:3]))mod 2^4

[0345] =dec(BCB[0:3])

[0346] Referring to Equation 30, PAID[8-N+1:8] is equal to BCB[0:N-1] (where N is 4).

[0347] As described above, in all cases, predetermined bits of the PAID, ie, PAID[8-N+1:8], have the same value as a partial BSS color value, ie, BCB[0:N-1].

[0348] Figure 27 FIG4 is a diagram illustrating a fourth embodiment of a method for determining a BSS intra-frame and a BSS inter-frame according to the present invention. Figure 24 The sixth embodiment described or reference Figure 26 When assigning AID in the seventh embodiment described, you can use Figure 27 The method for determining BSS intra-frame and BSS inter-frame is shown in .

[0349] First, the terminal receives a radio frame and extracts the 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 the group ID and PAID. Therefore, if the received frame is a VHT PPDU, the terminal extracts the group ID and PAID information from the preamble of the VHT PPDU.

[0350] Next, the terminal checks which information the extracted group ID represents (S2720). More specifically, the terminal checks whether the extracted group ID information is equal to 0 or 63. Figure 8In the embodiment described above, group ID 0 may indicate that the frame is an uplink frame. In addition, group ID 63 may indicate that the frame is a downlink frame. That is, the terminal can identify whether the frame is an uplink frame or a downlink frame by extracting the group ID information.

[0351] If the extracted group ID information is equal to 0 (i.e., indicating an uplink frame), the terminal checks whether the PAID extracted from the frame matches a specific bit value of the BSSID of the BSS associated with the terminal (S2730). In this case, the specific bit value of the BSSID may be BSSID[39:47]. As described above with reference to Figure 8 As described above, since the PAID is set to BSSID[39:47] in the case of an uplink frame, the terminal can determine whether the frame is an intra-BSS frame or an inter-BSS frame based on whether the PAID of the received frame matches the BSSID[39:47] of the BSS associated with the terminal. If the PAID matches the BSSID[39:47], the terminal determines the received frame as an intra-BSS frame (S2732). However, if the PAID does not match the BSSID[39:47], the terminal determines the received frame as an inter-BSS frame (S2734).

[0352] Meanwhile, if the extracted group ID information is equal to 63 (i.e., indicating a downlink frame), the terminal checks whether the PAID information extracted from the frame matches the partial BSS color announced to the terminal (S2740). In this case, the PAID information indicates a predetermined bit of the PAID. Figure 27 In the embodiment of the present invention, the predetermined bits of the PAID indicate PAID[8-N+1:8]. According to an embodiment of the present invention, N=4. In addition, the partial BSS color announced to the terminal indicates the partial BSS color announced by the AP associated with the terminal. If the AID is assigned according to the sixth or seventh embodiment of the present invention, when the PAID is set, the K-bit value based on the BSSID is offset by the N-bit value based on the BSSID. Therefore, the predetermined bits of the PAID (i.e., PAID[8-N+1:8]) indicate the partial BSS color announced to the intended recipient of the frame. Therefore, the terminal can determine whether the corresponding frame is an intra-BSS frame or an inter-BSS frame based on whether the predetermined bits of the PAID of the received frame match the partial BSS color announced to the terminal. If the predetermined bits of the PAID match the partial BSS color announced to the terminal, the terminal determines the received frame as an intra-BSS frame (S2742). However, if the predetermined bits of the PAID do not match the partial BSS color announced to the terminal, the terminal determines the received frame as an inter-BSS frame (S2744).

[0353] According to an embodiment of the present invention, a method for determining an intra-BSS frame and an inter-BSS frame when the extracted group ID information is equal to 63 can be performed only when the value N of the "Number of Partial BSS Color Bits Used for AID" field used for the non-legacy element most recently received from the associated AP is not 0. According to another embodiment of the present invention, a method for determining an intra-BSS frame and an inter-BSS frame when the extracted group ID information is equal to 63 can be performed only when 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, an AID assignment rule in which partial BSS color bits are used is applied.

[0354] Meanwhile, the AID assignment method according to the above embodiment can be applied only when allocating AIDs for VHT STAs. AID assignment candidate values ​​are limited, and if some BSS colors are used for AID assignment, the number of values ​​that can be assigned as AIDs is further reduced. Therefore, according to an embodiment of the present invention, the above AID assignment method can be applied restrictively to VHT STAs, thereby ensuring AID assignment margin for all STAs.

[0355] Although the present invention is described by using wireless LAN communication as an example, the present invention is not limited thereto and can be similarly applied to other communication systems, such as cellular communication, etc. In addition, although the method, apparatus, and system of the present invention are described in conjunction with specific embodiments, some or all of the components and operations of the present invention can be implemented by using a computer system having a general hardware structure.

[0356] The embodiments described in detail of the present invention may be implemented by various means. For example, the embodiments of the present invention may be implemented by hardware, firmware, software and / or a combination thereof.

[0357] In the case of hardware implementation, the method according to the embodiment of the present invention can be implemented by one or more of an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microcontroller, a microprocessor, etc.

[0358] In the case of firmware implementation or software implementation, the method according to the embodiment of the present invention can be implemented by modules, processes, functions, etc. that perform the operations described above. The software code can be stored in a memory and operated by a processor. The processor can be equipped with a memory internally or externally, and the memory can exchange data with the processor through various publicly known means.

[0359] The description of the present invention is for illustration, and those skilled in the art will be able to understand that, without changing the technical ideas or its essential features, the present invention can be easily modified into other detailed forms. Therefore, it should be understood that the above embodiments are intended to be illustrative in various senses, rather than restrictive. For example, each component described as a single type can be implemented as distributed, and similarly, the components described as distributed can also be implemented in an associated form.

[0360] The scope of the present invention is indicated by the claims to be described below, rather than the detailed description, and it is to be interpreted that the meaning and scope of the claims and all changes or modifications derived from equivalents thereof fall within the scope of the present invention.

[0361] Industrial Applicability

[0362] Various exemplary embodiments of the present invention have been described with reference to the IEEE 802.11 system, however, the present invention is not limited thereto and the present invention can be applied to various types of mobile communication devices, mobile communication systems, and the like.

Claims

1. A wireless communication terminal, comprising: processor; and Communication unit, Wherein, the processor is configured to: receiving a management frame including an association identifier AID, receiving a physical layer protocol data unit (PPDU) through the communication unit, and Identify whether the PPDU is an inter-BSS frame or an intra-BSS frame, wherein the AID is related to the determination of a partial AID for identifying the wireless communication terminal, wherein the first predetermined N bits of the AID assigned to the wireless communication terminal are determined using i) a partial BSS color value of a BSS color of a BSS associated with the terminal; and ii) an N-bit value of a BSSID of the BSS when an AID assignment rule using partial BSS color bits is applied; The partial AID of the PPDU is used to identify whether the PPDU is the inter-BSS frame or the intra-BSS frame.

2. The wireless communication terminal according to claim 1, in, The first predetermined N bits of the AID are determined based on a value obtained by subtracting an N-bit value based on the BSSID from the partial BSS color value.

3. The wireless communication terminal according to claim 2, in, The partial BSS color value is the value of the least significant N bits or the most significant N bits of the BSS color, and The N-bit value based on the BSSID is an exclusive OR of a first preset N-bit of the BSSID and a second preset N-bit of the BSSID.

4. The wireless communication terminal according to claim 1, in, The N is equal to 4.

5. The wireless communication terminal according to claim 1, in, The AID assignment rule is as follows: AID(8-N+1:8)=bin[(dec(BCB(0:N-1))-dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod 2^N,N] Here, the BCB is the BSS color, the BSSID is the BSS identifier, and N=4. The wireless communication terminal according to claim 1 , in, The preamble of the PPDU includes the partial AID, and The partial AID is set using the AID and K bits based on the BSSID.

7. The wireless communication terminal according to claim 6, in, The second predetermined N bits of the partial AID of the PPDU represent the partial BSS color value of the BSS, and Wherein, the K bits are offset based on the N-bit value of the BSSID.

8. The wireless communication terminal according to claim 1, in, The PPDU is identified as the inter-BSS frame or the intra-BSS frame according to whether the partial AID of the PPDU matches some bits of the BSSID of the BSS.

9. A wireless communication method for a wireless communication terminal, the method comprising: receiving a management frame including an association identifier AID; Receive physical layer protocol data unit PPDU; as well as Identify whether the PPDU is an inter-BSS frame or an intra-BSS frame, wherein the AID is related to the determination of a partial AID for identifying the wireless communication terminal, wherein the first predetermined N bits of the AID assigned to the wireless communication terminal are determined using i) a partial BSS color value of a BSS color of a BSS associated with the terminal; and ii) an N-bit value of a BSSID of the BSS when an AID assignment rule using partial BSS color bits is applied; The AID of the PPDU portion is used to identify whether the PPDU is the inter-BSS frame or the intra-BSS frame.

10. The wireless communication method according to claim 9, in, The first predetermined N bits of the AID are determined based on a value obtained by subtracting an N-bit value based on the BSSID from the partial BSS color value.

11. The wireless communication method according to claim 10, in, The partial BSS color value is the value of the least significant N bits or the most significant N bits of the BSS color, and The N-bit value based on the BSSID is an exclusive OR of a first preset N-bit of the BSSID and a second preset N-bit of the BSSID.

12. The wireless communication method according to claim 9, in, The N is equal to 4.

13. The wireless communication method according to claim 9, in, The AID assignment rule is as follows: AID(8-N+1:8)=bin[(dec(BCB(0:N-1))-dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod 2^N,N] Here, the BCB is the BSS color, the BSSID is the BSS identifier, and N=4.

14. The wireless communication method according to claim 9, in, The preamble of the PPDU includes the partial AID, and The partial AID is set using the AID and K bits based on the BSSID.

15. The wireless communication method according to claim 14, in, The second predetermined N bits of the partial AID of the PPDU represent the partial BSS color value of the BSS, and Wherein, the K bits are offset based on the N-bit value of the BSSID.

16. The wireless communication method according to claim 9, in, The PPDU is identified as the inter-BSS frame or the intra-BSS frame according to whether the partial AID of the PPDU matches some bits of the BSSID of the BSS.

17. An access point (AP), comprising: processor; and Communication unit, Wherein, the processor is configured to: Send a management frame including the association identifier AID, sending a physical layer protocol data unit (PPDU) via the communication unit, and The AID is related to the determination of a partial AID for identifying a non-AP STA. wherein the first predetermined N bits of the AID allocated to the non-AP STA are determined using i) a partial BSS color value of a BSS color of a BSS associated with the non-AP STA; and ii) an N-bit value of a BSSID of the BSS when an AID allocation rule using partial BSS color bits is applied; The partial AID of the PPDU is used to identify whether the PPDU is an inter-BSS frame or an intra-BSS frame.

18. The AP according to claim 17, in, The first predetermined N bits of the AID are determined based on a value obtained by subtracting an N-bit value based on the BSSID from the partial BSS color value.

19. The AP according to claim 18, in, The partial BSS color value is the value of the least significant N bits or the most significant N bits of the BSS color, and The N-bit value based on the BSSID is an exclusive OR of a first preset N-bit of the BSSID and a second preset N-bit of the BSSID.

20. The AP according to claim 17, in, The N is equal to 4.

21. The AP according to claim 17, The AID assignment rule is as follows: AID(8-N+1:8)=bin[(dec(BCB(0:N-1))-dec(BSSID(47-N+1:47)XOR BSSID(43-N+1:43)))mod 2^N,N] in, The BCB is a BSS color, the BSSID is a BSS identifier, and N=4.

22. The AP according to claim 17, in, The preamble of the PPDU includes the partial AID, and The partial AID is set using the AID and K bits based on the BSSID.

23. The AP according to claim 22, in, The second predetermined N bits of the partial AID of the PPDU represent the partial BSS color value of the BSS, and Wherein, the K bits are offset based on the N-bit value of the BSSID.

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