Wireless communication method and wireless communication terminal using a basic service set

Abstract

The present invention relates to a wireless communication method and a wireless communication terminal using a basic service set. More specifically, a wireless communication method and a wireless communication terminal that perform operations based on a determination result of whether a received frame is an in-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 includes: a processor; and a communication unit. The processor receives a wireless frame through the communication unit. When the received frame is a VHT PPDU, the processor extracts partial association ID (AID) information and group ID information from the preamble of the VHT PPDU. If the extracted group ID information is equal to a predetermined value, the processor confirms whether at least some of the information in the extracted partial AID matches a partial BSS color known to the terminal, and based on whether at least some of the information in the partial AID matches the partial BSS color, determines whether the received frame is an in-BSS frame or an inter-BSS frame.

Description

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

[0002] The present invention relates to a wireless communication method and a wireless communication terminal for determining basic service set identification information using received frames, and more particularly, to a wireless communication method and a wireless communication terminal that perform operations according to a determination result as to whether a received frame is an in-BSS frame or an inter-BSS frame. Background Art

[0003] In recent years, with the expansion of the supply of mobile devices, wireless LAN technology that can provide fast wireless Internet services to mobile devices has received attention. Wireless LAN technology allows mobile devices including smart phones, smart tablets, laptop computers, portable multimedia players, embedded devices, etc. to wirelessly access the Internet in a home or company or a specific service providing area based on short-range wireless communication technology.

[0004] Since the initial wireless LAN technology was supported using a frequency of 2.4 GHz, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technical standards. First, IEEE 802.11b supports a maximum communication speed of 11 Mbps when using a frequency in the 2.4 GHz band. Compared with the significantly congested frequency in the 2.4 GHz band, IEEE 802.11a, which was commercialized after IEEE 802.11b, uses a frequency in the 5 GHz band instead of the 2.4 GHz band to reduce the impact of interference, and by using OFDM technology, increases the communication speed to a maximum of 54 Mbps. However, a disadvantage 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 a frequency in the 2.4 GHz band to achieve a maximum communication speed of 54 Mbps and satisfies backward compatibility, which has attracted significant attention, and in terms of communication distance, is superior to IEEE 802.11a.

[0005] In addition, as a technical standard established to overcome the limitations of communication speed pointed out as a weakness in wireless LANs, IEEE 802.11n has been provided. IEEE 802.11n aims to increase the speed and reliability of the network and extend the working distance of the wireless network. More specifically, IEEE 802.11n supports High Throughput (HT), where the data processing speed is 540 Mbps or higher at maximum, and further, based on Multiple Input and Multiple Output (MIMO) technology, where multiple antennas are used on both sides of the transmitting unit and the receiving unit to minimize transmission errors and optimize the data speed. In addition, this standard can use an encoding scheme that transmits multiple superimposed copies in order to increase data reliability.

[0006] As wireless LANs are actively provided and, further, the applications using wireless LANs are diversified, the demand for a new wireless LAN system that supports a higher throughput (Very High Throughput (VHT)) than the data processing speed supported by IEEE 802.11n has received attention. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) in the 5 GHz frequency band. The IEEE 802.11ac standard is defined only in the 5 GHz band, but the initial 11ac chipset even supports operation in the 2.4 GHz band for backward compatibility with existing 2.4 GHz band products. Theoretically, according to this standard, the wireless LAN speed of multiple stations can be enabled to reach at least 1 Gbps, and the maximum single-link speed can be enabled to reach at least 500 Mbps. This is achieved by expanding the concept of the wireless interface accepted by 802.11n, such as a wider wireless bandwidth (maximum 160 MHz), more MIMO spatial streams (maximum 8), multi-user MIMO, and high-density modulation (maximum 256QAM). In addition, as a scheme for transmitting data by using the 60 GHz band instead of the existing 2.4 GHz / 5 GHz, IEEE 802.11ad has been provided. IEEE 802.11ad is a transmission standard that provides a speed of up to 7 Gbps by using beamforming technology and is suitable for high bit rate moving image streams such as mass data or uncompressed HD video. However, since the 60 GHz band has difficulty passing through obstacles, its disadvantage is that the 60 GHz band can only be used in devices in a short-distance space.

[0007] Meanwhile, in recent years, as the next-generation wireless LAN standard after 802.11ac and 802.11ad, discussions on providing an efficient and high-performance wireless LAN communication technology in a high-density environment have been continuously carried out. That is, in the next-generation wireless LAN environment, in the presence of high-density stations and access points (APs), it is necessary to provide communication with high spectral efficiency indoors / outdoors, and various technologies for realizing this communication are required. Summary of the Invention

[0008] Technical problem

[0009] The present invention aims to provide high-efficiency / high-performance wireless LAN communication in the high-density environment as described above.

[0010] In addition, the present invention aims to set rules for AID assignment for STAs in a BSS.

[0011] In addition, the present invention aims to prevent ambiguity that may occur in the determination within / among BSSs using partial AID information of a VHT PPDU.

[0012] Technical solution

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

[0014] First, an exemplary embodiment of the present invention provides a basic wireless communication terminal, which includes: a processor; and a communication unit, where the processor assigns an association ID (AID) to at least one terminal associated with the basic wireless communication terminal, and a 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] In addition, an exemplary embodiment of the present invention provides 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 sending the assigned AID information to the terminal associated with the basic wireless communication terminal, where a 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 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 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))) mod 2^N, N]

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

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

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

[0023] The partial 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, which includes: a processor; and a communication unit. When the received frame is a VHT PPDU, the processor receives a wireless frame through the communication unit, extracts partial association ID (AID) information and group ID information from the 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 the partial basic service set (BSS) color announced to the terminal, and determines whether the received frame is an in-BSS frame or an inter-BSS frame according to 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 for 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 the 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 the partial basic service set (BSS) color announced to the terminal; and determining whether the received frame is an in-BSS frame or an inter-BSS frame according to whether at least some information of the partial AID matches the partial BSS color.

[0026] The partial AID can be determined using the AID assigned to the intended recipient of the VHT PPDU and the K-bit value based on the BSSID of the BSS associated with the recipient. When the BSS to which the terminal belongs applies the AID assignment rule using partial BSS color bits, the predetermined N bits of the AID assigned in the BSS to which the terminal belongs can be determined by using the partial BSS color value announced to the terminal and the 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 can be determined based on the value obtained by subtracting the N-bit value of the BSSID of the BSS to which the terminal belongs from the 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, the predetermined bits of the partial AID can represent the partial BSS color value announced to the receiver, where the K-bit value based on the BSSID is offset by the N-bit value of the BSSID of the BSS associated with the receiver.

[0029] The partial BSS color value can be 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 can be the exclusive OR value of the first predetermined N bits of the BSSID and the 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))) mod 2^N, N]

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

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

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

[0036] When the received frame is determined to be an in-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 can have a value equal to or higher than the first CCA threshold.

[0038] When the received frame is determined to be an in-BSS frame, the processor may set or update the first Network Allocation Vector (NAV), and when the received frame is determined to be an inter-BSS frame, the processor may set or update the second NAV.

[0039] Advantageous 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 effective in-BSS / inter-BSS frame determination.

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

[0042] In addition, according to an embodiment of the present invention, if the received frame is determined to be an inter-BSS frame, wireless resources can thus be effectively used to perform a spatial reuse operation.

[0043] According to an embodiment 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 Illustrates a wireless LAN system according to an embodiment of the present invention.

[0045] Figure 2 Illustrates a wireless LAN system according to another embodiment of the present invention.

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

[0047] Figure 4 Illustrates the configuration of an access point according to an embodiment of the present invention.

[0048] Figure 5 Schematically illustrates the process of a STA and an AP setting a link.

[0049] Figure 6 Illustrates the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) method used in wireless LAN communication.

[0050] Figure 7 Illustrates the configuration of VHT-SIG-A1 and VHT-SIG-A2 according to an embodiment of the present invention.

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

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

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

[0054] Figure 11 Illustration in more detail of a partial AID calculation process according to an embodiment of the present invention.

[0055] Figure 12 Illustration of a first embodiment of a method for determining intra - BSS frames and inter - BSS frames according to the present invention.

[0056] Figure 13 Illustration of a second embodiment of a method for determining intra - BSS frames and inter - BSS frames according to the present invention.

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

[0058] Figure 15 Illustration of a non - traditional element format according to another embodiment of the present invention.

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

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

[0061] Figure 18 Illustration of a third embodiment of an AID assignment method according to the present invention.

[0062] Figure 19 Illustration of a fourth embodiment of an AID assignment method according to the present invention.

[0063] Figure 20 And 21 Illustration of a fifth embodiment of an AID assignment method according to the present invention.

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

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

[0066] Figure 24 Illustration of a sixth embodiment of an AID assignment method according to the present invention.

[0067] Figure 25 Illustrates a non - traditional element format according to another embodiment of the present invention.

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

[0069] Figure 27 Illustrates a fourth embodiment of the method for determining intra - BSS frames and inter - BSS frames according to the present invention. Detailed Description of the Invention

[0070] By considering the functions of the present invention, the terms used in this specification adopt the general terms that are currently widely used. However, the terms can be changed according to the intention of those skilled in the art, habits, and the emergence of new technologies. In addition, in specific cases, there are terms arbitrarily selected by the applicant, and in such cases, their meanings will be described in the corresponding description part 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 substantial meaning of the term and the content of the entire specification.

[0071] Throughout this specification and the following claims, when it describes that one element is "coupled" to another element, the element can be "directly coupled" to another element, or "electrically coupled" to another element via a third element. In addition, unless there is a contrary and explicit description, the word "comprising" and variations such as "including" or "includes" will be understood to implicitly include the stated elements, but do not exclude any other elements. In addition, limitations such as "or more" or "or less" based on a specific threshold can be appropriately replaced with "greater than" or "less than" respectively.

[0072] This application claims the priority and benefits of Korean Patent Applications 10 - 2016 - 0040551, 10 - 2016 - 0093812, and 10 - 2016 - 0102229 filed with the Korean Intellectual Property Office, and the embodiments and matters described in the corresponding applications that form the basis of the priority will be included in the detailed description of this application.

[0073] Figure 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 Illustrates the infrastructure BSS between them.

[0074] As inFigure 1 As shown in the figure, the basic service set (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 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 predefined device that includes a media access control (MAC) conforming to the provisions of the IEEE 802.11 standard and a physical layer interface for a wireless medium, and broadly includes both non-access point (non-AP) stations and access points (APs). In addition, in this specification, the term "terminal" can 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 can generate frames to be transmitted via a wireless network, or process frames received via a wireless network, and in addition, execute 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 can be used as a term including 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 therewith. In a basic service set (BSS), communication among non-AP stations is in principle performed via an AP, but when a direct link is configured, direct communication among non-AP stations is even allowed. At the same time, in the present invention, an AP is used as a concept including a personal BSS coordination point (PCP), and broadly can include concepts including a central controller, a base station (BS), a Node B, a base station transceiver system (BTS), and a site controller. In the present invention, an AP can also be referred to as a base station wireless communication terminal. A base station wireless communication terminal can be used as a term that broadly includes an AP, a base station, an eNB (i.e., an eNode B), and a transmission point (TP). In addition, a base station wireless communication terminal can include various types of wireless communication terminals that allocate media resources and perform scheduling for communicating with multiple wireless communication terminals.

[0077] Multiple basic service sets (BSSs) can be interconnected via a distribution system (DS). In this case, multiple BSSs connected via a distribution system are called an extended service set (ESS).

[0078] Figure 2 An independent BSS according to another embodiment of the present invention is shown, which is a wireless LAN system. In Figure 2 the embodiment, a repeated description of parts identical or corresponding to Figure 1 the embodiment will be omitted.

[0079] Since the BSS3 illustrated in Figure 2 is an independent BSS and does not include an AP, all stations STA6 and STA7 are not connected to the AP. An independent BSS is not allowed to access the distribution system and forms a self - contained network. In the independent BSS, the corresponding stations STA6 and STA7 can be directly connected to each other.

[0080] Figure 3 is a block diagram illustrating the configuration of a station 100 according to an embodiment of the present invention. As illustrated in Figure 3 the 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, etc., and may be embedded in the station 100 or provided as a peripheral. According to this embodiment, the communication unit 120 may include at least one communication module using different frequency bands. For example, the communication unit 120 may include communication modules having different frequency bands, such as 2.4 GHz, 5 GHz, and 60 GHz. According to an embodiment, the station 100 may include a communication module using a frequency band of 6 GHz or higher and a communication module using a frequency band of 6 GHz or lower. The corresponding communication module may perform wireless communication with an AP or an external station according to the wireless LAN standard of the frequency band supported by the corresponding communication module. The communication unit 120 may operate only one communication module at a certain time or operate multiple communication modules together simultaneously according to the performance and requirements of the station 100. When the station 100 includes multiple communication modules, each communication module may be implemented by independent components, or multiple modules may be integrated into one chip. In an embodiment 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 may receive user input by using various input devices, and the processor 110 may control the station 100 based on the received user input. In addition, the user interface unit 140 may 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 based on the control commands of the processor 110, such as the content executed by the processor 110 or the user interface, etc. In addition, the memory 160 stores control programs and various result data used in the station 100. The control program can 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 in the station 100. In addition, the processor 110 can control each unit of the station 100 and control data transmission / reception among the units. According to an embodiment of the present invention, the processor 110 can execute a program for accessing the AP stored in the memory 160 and receive a communication configuration message sent by the AP. In addition, the processor 110 can read information about the priority conditions of the station 100 included in the communication configuration message and request access to the AP based on the information about the priority conditions of the station 100. The processor 110 of the present invention can represent the main control unit of the station 100, and according to this embodiment, the processor 110 can represent a control unit for separately controlling certain components of the station 100, such as the communication unit 120, etc. That is, the processor 110 can be a modem or a modulator / demodulator for modulating the wireless signal sent to the communication unit 120 and demodulating the wireless signal received from the communication unit 120. The processor 110 controls various operations of the wireless signal transmission / reception of the station 100 according to an embodiment of the present invention. Its detailed embodiments will be described below.

[0085] In Figure 3 The station 100 illustrated in

[0086] Figure 4 is a block diagram of the configuration of the AP 200 according to an embodiment of the present invention, where individual blocks are illustrated as elements of logically distinct devices. Therefore, the elements of the device can be installed in a single chip or multiple chips according to the design of the device. For example, the processor 110 and the communication unit 120 can be implemented when integrated into a single chip or as separate chips. In addition, in an embodiment of the present invention, certain components of the station 100, such as the user interface unit 140 and the display unit 150, can be selectively provided in the station 100.

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

[0087] Reference 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. As described in the embodiments of Figure 3 , the communication unit 220 of the AP 200 may also include a plurality of communication modules using different frequency bands. That is, the AP 200 according to an embodiment of the present invention may include two or more communication modules among 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 higher and a communication module using a frequency band of 6 GHz or lower. 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 certain time or operate multiple communication modules together simultaneously according to the performance and requirements of the AP 200. In an 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 and various result data used in the AP 200. The control program may include an access program for managing access by stations. In addition, the processor 210 may control each unit of the AP 200 and control data transmission / reception among the units. According to an embodiment of the present invention, the processor 210 may execute a program 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 about access priority conditions for each station. In addition, the processor 210 performs access configuration according to an access request from a station. According to one embodiment, the processor 210 may be a modem or a modulator / demodulator for modulating a wireless signal sent to the communication unit 220 and demodulating a wireless signal received from the communication unit 220. The processor 210 controls various operations such as wireless signal transmission / reception of the AP 200 according to an embodiment of the present invention. Its detailed embodiments will be described below.

[0089] Figure 5 is a diagram schematically illustrating a process of a STA setting a link with an AP.

[0090] Reference Figure 5, In general, the link between the STA 100 and the AP 200 is set through three steps of scanning, authentication, and association. First, the scanning step is the step in which the STA 100 obtains access information of the BSS operated by the AP 200. The methods for performing scanning include a passive scanning method in which the AP 200 obtains information by using beacon messages (S101) periodically transmitted, and an active scanning method in which the STA 100 sends a probe request to the AP (S103) and obtains access information by receiving a probe response from the AP (S105).

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

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

[0093] Figure 6 The figure illustrates the Carrier Sense Multiple Access with Collision Avoidance (CSMA) / CA method used in wireless LAN communication.

[0094] The terminal performing wireless LAN communication checks whether the channel is busy by performing carrier sensing before transmitting data. When a wireless signal with a predetermined intensity or more is sensed, it is determined that the corresponding channel is busy, and the terminal delays access to the corresponding channel. Such a process is called Clear Channel Assessment (CCA), and the determination of whether a signal with a CCA threshold or more is sensed is called the CCA threshold. When a wireless signal with a CCA threshold or more received by the terminal indicates that the corresponding terminal is a receiver, the terminal processes the received radio signal. Meanwhile, when no wireless signal is sensed in the corresponding channel, or a wireless signal with an intensity less than the CCA threshold is sensed, it is determined that the channel is idle.

[0095] When it is determined that the channel is idle, according to the situation of each terminal, after an Inter-Frame Space (IFS) time, such as Arbitration IFS (AIFS), PCF IFS (PIFS), etc. elapses, each terminal having data to transmit performs a backoff process. According to this embodiment, AIFS can be used as a component to replace the existing DCF IFS (DIFS). As long as a random number is determined by the corresponding terminal during the interval of the idle state of the channel, each terminal prepares when the slot time decreases, and the terminal that completely exhausts the slot attempts to access the corresponding channel. Thus, the interval during which each terminal performs the backoff process is called the contention window interval.

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

[0097] Figure 7 Illustrates the configurations of VHT-SIG-A1 and VHT-SIG-A2 according to an embodiment of the present invention. The preamble of a VHT Physical Layer Protocol Data Unit (PPDU) includes a VHT-SIG-A field, and VHT-SIG-A is composed of VHT-SIG-A1 and VHT-SIG-A2. VHT-SIG-A1 and VHT-SIG-A2 carry information necessary to interpret the VHT PPDU.

[0098] Reference Figure 7 , the partial Association ID (AID) field composed of 9 bits can be included in the VHT-SIG-A1 of a single-user PPDU. The partial AID field can represent abbreviated information about the intended recipient of the corresponding Physical Layer Service Data Unit (PSDU). The Group ID field of VHT-SIG-A1 is set to 0 or 63 in the case of an SU PPDU, and set to other values in the case of a multi-user (MU) PPDU. A terminal can check the partial AID (or partial AID and Group ID) of the received VHT PPDU, and if the intended recipient of the PPDU is not the terminal, stop decoding.

[0099] In the following, a method for setting the group ID and the partial AID according to an embodiment of the present invention will be described with reference to each drawing. 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 the bits from bit b to bit c of "A". According to an embodiment of the present invention, the first bit of "A" can be bit 0, and A[b:c] can represent the (b + 1)-th bit to the (c + 1)-th bit of "A".

[0101] - dec(A[b:c]) represents the value of the bits from bit b to bit c of "A" represented by 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^(c - b). dec(A[b:c]) and A[b:c] only differ in the type of information expression and represent substantially 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 a 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 showing a method for setting the group ID and the partial AID according to an embodiment of the present invention.

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

[0108] Next, in the PPDU or PSDU addressed to the 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] In an embodiment of the present invention, in a PPDU or PSDU that satisfies the following conditions, the group ID can be set to 63, and the partial AID (hereinafter, PAID) can be set as shown in Equation 1 below. i) A PPDU or PSDU sent by an AP and addressed to an STA associated with the AP (i.e., a downlink frame). ii) A PPDU or PSDU sent by a direct link setup (DLS) STA or a tunnel 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, PAID is determined by a combination of AID information and BSSID information. More specifically, PAID is determined based on a value obtained by adding the XOR of some bits of the BSSID and the value of some bits of the AID. In the process of summing the AID information and the BSSID information, according to the AID setting rule, the PAID of the downlink frame may lose the BSS identification ability of STAs other than the intended receiver. At the same time, in cases other than those 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 way can be included in the VHT-SIG of the VHT PPDU. The AP that sends the VHT PPDU determines the PAID information and the BSSID information, and sends the PAID information by including the PAID information in the VHT-SIG. In this case, the AID information indicates the value of some bits of the AID assigned to the intended receiver of the corresponding PPDU. In addition, the BSSID information indicates the value of the BSSID of the BSS to which the AP that sends the PPDU and the receiver of the PPDU belong. The XOR of some bits of the BSSID is indicated based on the value of the BSSID. More specifically, the XOR of the first predetermined K bits of the BSSID and the second predetermined K bits of the BSSID is indicated based on the value of the BSSID. As in the embodiment of Equation 1, K can be set to 4, the first predetermined K bits can indicate the bits from bit 44 to bit 47, and the second predetermined K bits can indicate the bits from bit 40 to bit 43. Hereinafter, in the embodiment of the present invention, the value of the BSSID used to set PAID will be referred to as the "K-bit value based on the BSSID". On the other hand, since PAID is determined according to the AID, different values can be determined according to the AID assignment method.

[0114] When the AP sends a VHT PPDU to the STA, the AP uses the AID information of the STA and the K-bit value based on the BSSID to set the PAID. In this case, the AID of the STA can be set by any one of the embodiments of the present invention described below. 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] Hereinafter, an AID assignment method according to various embodiments of the present invention will be described with reference to the drawings and equations. The AP can assign an AID to each STA using at least one of the embodiments described below. According to an embodiment, the AP can assign an AID determined by the following rules to the VHT STA. In addition, the AP can send the assigned AID information to the terminals associated with the AP. In each embodiment, a repeated description of the same or corresponding parts as in 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 rule of Equation 2. In this case, the BCB indicates the partial BSS color or the BSS color. The AP operating the BSS notifies the partial BSS color to the STA associated with the BSS. According to an embodiment of Equation 2, the BCB information and the BSSID information can be used to determine a predetermined N bits of the AID. The BCB information is the 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 thereto, and the BCB information may represent the value of the most significant N bits of the BSS color. The BSSID information represents the value of the BSSID of the BSS operated by the AP that assigns the AID. The value based on the BSSID represents the exclusive OR of some bits of the BSSID. More specifically, the 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. According to an embodiment of Equation 2, the first predetermined N bits indicate the bits from bit 47-N+1 to bit 47, and the second predetermined N bits may indicate the bits from bit 43-N+1 to bit 43. Hereinafter, in an embodiment of the present invention, the value based on the BSSID used for AID assignment will be referred to as the "N-bit value based on the BSSID".

[0121] When the AID is assigned as described above, the predetermined bits of the PAID determined according to an embodiment of Equation 1, i.e., PAID(8-N+1:8), can have BSS identification ability. When the PAID has BSS identification ability, a non-traditional terminal can 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 compliant with the next-generation wireless LAN standard (i.e., IEEE 802.11ax). An intra-BSS frame indicates a frame sent by a terminal belonging to the same BSS, and an inter-BSS frame indicates a frame sent by a terminal belonging to another BSS.

[0122] The non-traditional terminal can perform intra-BSS frame and inter-BSS frame determination using information for identifying the BSS, such as BSS color, partial BSS color, MAC address, etc. 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, i.e., PAID(8-N+1:8).

[0123] The non - traditional terminal can perform different operations according to whether the received frame is an in - BSS frame. That is, when the received frame is determined to be an in - BSS frame, the terminal can perform a first operation. Additionally, when the received frame is determined to be an inter - BSS frame, the terminal can perform a second operation different from the first operation. According to an embodiment of the present invention, the first operation and the second operation can be set in various ways.

[0124] According to an embodiment, the terminal can perform channel access based on different thresholds depending on whether the received frame is an in - BSS frame. More specifically, when the received frame is determined to be an in - BSS frame, the terminal accesses the channel based on a first CCA threshold (i.e., the 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 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., the 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 a set of overlapping basic service set (OBSS) PD levels for determining whether the channel is busy according to the received signal strength between BSS frames. In this case, the second CCA threshold can have a value equal to or higher than the first CCA threshold.

[0125] According to another embodiment, the terminal can set or update different network allocation vectors (NAVs) according to whether the received frame is an in - BSS frame. More specifically, when the received frame is determined to be an in - BSS frame, the terminal sets or updates a first NAV based on the duration information of the corresponding frame (i.e., the first operation). In this case, the first NAV can be an in - BSS NAV that is managed to protect in - 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., the second operation). In this case, the second NAV can be a basic NAV that is 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 - traditional terminal extracts group ID information and PAID information from the preamble of the corresponding frame (i.e., VHT - SIG - A). When the extracted group ID information is equal to a predetermined value (e.g., 63), the non - traditional terminal can determine whether the frame is an in - BSS frame or an inter - BSS frame based on the extracted PAID information. More specifically, the terminal performs the determination of in - BSS frame and inter - BSS frame by comparing the extracted PAID information with the information for identifying the BSS associated with the terminal. As will be described later, the information for identifying the BSS associated with the terminal includes the PAID of the terminal according to the 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 of the group ID information (i.e., 63) indicates that the frame is a downlink frame.

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

[0128] Figure 9 Illustrates a non - traditional element format according to an embodiment of the present invention. The AP can use the element shown in Figure 9 to announce partial BSS color information to the STA. The non - traditional element can be included in a beacon frame, a probe request frame, a probe response frame, an association request frame, an association response frame, a re - association request frame, a re - association response frame, etc. Additionally, the non - traditional element can also be sent via a frame that only contains the element.

[0129] Referring to Figure 9 , the non - traditional element can 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., "Partial BSS Color Information Element"). The "Length" field represents the length information of the corresponding element. The "Partial BSS Color Information" field can include a "Number of Partial BSS Color Bits for AID" field, a "Partial BSS Color Bits" field, and a reserved field. According to an embodiment, the "Partial BSS Color Information" field can include a "Number of Partial BSS Color Bits for AID" field and a 4 - bit "Partial BSS Color Bits" field.

[0130] The "Number of Partial BSS Color Bits 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 can be used for AID determination. According to an embodiment, N can indicate any value between 1 and the maximum number of partial BSS color bits (e.g., 4). According to another embodiment, N can also indicate 0 to indicate that the partial BSS color is not used in AID assignment. If N indicates 0, the in / intra-BSS frame determination method using the PAID information of the VHT PDU may not be used. According to an embodiment of the present invention, when the value of the "Number of Partial BSS Color Bits for AID" field (i.e., N) is set to a value greater than 0, the AP can assign the AID according to the method of Equation 2.

[0131] The "Partial BSS Color Bits" field represents the bit value of the partial BSS color. The "Partial BSS Color Bits" field can represent the BCB value of Equation 2. In addition, when determining the AID according to an embodiment of the present invention, the "Partial BSS Color Bits" field can 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 can be determined independently of the BSS color. In this way, the problem of the partial BSS color value overlapping with the color values of neighboring BSSs can be reduced. According to another embodiment, the bit value of the partial BSS color can be determined depending on the BSS color. In this way, the receiver receiving the BSS color information can estimate the partial BSS color bit value based on this. According to an embodiment of the present invention, the "Partial BSS Color Bits" field can be variably determined according to 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 advertises the set partial BSS color to the STAs associated with the BSS. If multiple BSSID sets are used, the 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 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 N of bits, 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 N of bits, the AP may reduce the value of the number N of bits 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 N of bits 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 the new partial BSS color bits. In addition, the AP may change the partial BSS color bit values used in the corresponding BSS. The AP may send Figure 9 the elements shown in 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 FIG. illustrates a partial AID calculation process according to an embodiment of the present invention. Refer to Figure 10 , Figure 10 (a), dec(AID[0:8]) (hereinafter referred to as "specific bit information of the AID") and Figure 10 (b), dec(BSSID[44:47] XOR BSSID[40:43]) * 2^5 (hereinafter, "information obtained from the BSSID") are summed in the PAID calculation process according to Equation 1. In this case, in the information obtained from the BSSID, through the multiplication operation of 2^5, the five bits from B0 to B4 are all 0.

[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] can be determined as variable values. Therefore, multiple PAID(8-N+1:8) values can be determined within the BSS according to 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 be rounded or may not be rounded. If this ambiguity is not resolved, it may result in misidentifying a frame within the BSS as an inter-BSS frame.

[0136] When performing BSS-internal frame and BSS-interframe determination based on the PAID information of the received frame, the terminal may check whether the PAID information extracted from the received frame matches the PAID information related to the BSS to which the terminal is associated. Here, the PAID information indicates a predetermined number of bits of the PAID. More specifically, the PAID information may 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 to which the terminal is associated, the terminal determines the received frame as a BSS-internal frame. However, when the PAID information extracted from the received frame does not match the PAID information related to the BSS to which the terminal is associated, the terminal determines the received frame as a BSS-interframe.

[0137] Meanwhile, due to the ambiguity in the determination of the above PAID value, various PAID comparison methods can be used to solve this problem. According to an embodiment, the terminal compares the PAID(8 - N + 1:8) extracted from the received frame with all possible PAID(8 - N + 1:8) to perform the determination of BSS-internal / interframe. If the PAID(8 - N + 1:8) extracted from the received frame matches any of the possible PAID(8 - N + 1:8) in the BSS to which the terminal is associated, the terminal determines the received frame as a BSS-internal frame. However, if the PAID(8 - N + 1:8) extracted from the received frame does not match any of the possible PAID(8 - N + 1:8) in the BSS to which the terminal is associated, the terminal determines the received frame as a BSS-interframe. According to an embodiment of the present invention, when the group ID of the received frame is equal to a predetermined value (for example, 63), the BSS-internal frame and BSS-interframe determination may be performed.

[0138] According to another embodiment, the terminal performs in / intra-BSS frame determination by comparing the PAID(8-N+1:8) extracted from the received frame with i) the PAID(8-N+1:8) of the BSS associated with the terminal, ii) the 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) the 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. 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), in / intra-BSS frame determination can be performed.

[0139] To solve the problems caused by the ambiguity in the above PAID value determination, additional rules can be applied in AID assignment. According to an embodiment, B(8-N+1-1) of the AID can always be set to 0. According to another embodiment, when the B(8-N+1-1) value of the information obtained from the BSSID is 0, B(8-N+1-1) of the AID can always be set to 0.

[0140] On the other hand, the partial BSS color can be set to the same value in different BSSs. Therefore, if the in / intra-BSS frame determination result based on the partial BSS color is different from the in / intra-BSS frame determination result 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 the received frame is determined as an intra-BSS frame based on the partial BSS color, but the received frame is determined as an inter-BSS frame based on the MAC address, the terminal determines the received frame as an inter-BSS frame. Additionally, 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 satisfied, the terminal can determine the received frame as an inter-BSS frame.

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

[0142] Figure 11More specifically, the partial AID calculation process according to an embodiment of the present invention is illustrated. The AP may set the PAID according to the embodiment of Equation 1, and Figure 11 (a) and 11(b) illustrate the corresponding processes. As Figure 11 shown in (b), x represents the bits of the AID from bit 0 to bit 8 (i.e., AID[0:8]), and y represents (BSSID[44:47] XOR BSSID[40:43]) * 2^5. z represents the sum of x and y. Additionally, Figure 11 (c) illustrates the assignment rule for the bits from bit (8 - N + 1) to bit 8 (i.e., AID[8 - N + 1:8]) according to Equation 2.

[0143] Reference will be made to Figure 11 (a) to 11(c) to describe the process of calculating the PAID. When assigning the AID according to the Figure 11 rule of (c), the high N bits of x are assigned according to the Figure 11 rule of (c). 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 such that the AID assignment method according to the Figure 11 rule of (c) and the BSS intra / inter-frame determination method using the PAID may not be performed. N can be carried by the non-conventional elements described in Figure 9 , but the present invention is not limited thereto. Through the *2^5 operation in Figure 11 (b), the low 5 bits of y are all set to 0 (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 raised from bit position B8 to bit position B9 when calculating z by adding x and y, the mod operation truncates the raised value.

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

[0145] On the other hand, if the ambiguity in determining in-BSS frames and between-BSS frames is not resolved, an in-BSS frame may be incorrectly determined as a between-BSS frame. If an in-BSS frame is incorrectly determined as a between-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 in-BSS frames. If the terminal performs channel access based on the second CCA threshold, it may interfere with the received packets. Additionally, since the AP is transmitting packets, the AP cannot receive the packets transmitted by the terminal. In this way, the in-BSS / between-BSS frame determination error of the terminal may interfere with in-BSS operations.

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

[0147] Figure 12 FIG. 7 illustrates a first embodiment of a method for determining in-BSS frames and between-BSS frames according to the present invention. According to an embodiment of the present invention, a plurality of PAID (8-N+1:8) values can be determined in a BSS based on the assigned AID value and BSSID value. Therefore, the terminal can compare the PAID (8-N+1:8) extracted from the received frame with all possible PAID (8-N+1:8) in the BSS to which the terminal is associated to perform in-BSS / between-BSS frame determination. If the PAID (8-N+1:8) extracted from the received frame matches any of the possible PAID (8-N+1:8) in the BSS to which the terminal is associated, the terminal determines the received frame as an in-BSS frame. However, if the PAID (8-N+1:8) extracted from the received frame does not match any of the possible PAID (8-N+1:8) in the BSS to which the terminal is associated, the terminal determines the received frame as a between-BSS frame.

[0148] Figure 12 (a) and 12(b) illustrate a method for determining whether a received frame is an in-BSS frame or a between-BSS frame based on the PAID calculation process of the receiving terminal. Figure 12 (a) illustrates the determination method in the case where the number of elevated bits is at B(8-N+1-1) in the PAID calculation process of the terminal illustrated in Figure 10 and Figure 11 . Additionally, Figure 12 (b) illustrates the case in Figure 10 and Figure 11Determination method in the PAID calculation process of the terminal illustrated in the figure without increasing the number of bits at B(8 - N + 1 - 1).

[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 with 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 of the following (S1220). a-i) The PAID(8 - N + 1:8) of the terminal, a-ii) The PAID(8 - N + 1:8) of the terminal - 1(8 - N + 1). Here, 1(8 - N + 1) indicates the value 1 of the bit (8 - N + 1) of the PAID. Since in Figure 12 (a)'s embodiment, the number of bits has been increased during the PAID calculation process of the terminal, the PAID'(8 - N + 1:8) obtained by subtracting 1 from the PAID(8 - N + 1:8) of the terminal may exist in the BSS. Therefore, the terminal determines whether the PAID(8 - N + 1:8) of the received frame matches any of a-i) and a-ii) above. If the PAID(8 - N + 1:8) extracted from the received frame matches any of a-i) and a-ii), the terminal determines the received frame as an in-BSS frame (S1230). However, if the PAID(8 - N + 1:8) extracted from the received frame does not match any of a-i) 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 PAID information from the received frame (S1260). In this case, the group ID can be extracted together with 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 of the following (S1270). b-i) The PAID(8 - N + 1:8) of the terminal, b-ii) The PAID(8 - N + 1:8) of the terminal + 1(8 - N + 1). Here, 1(8 - N + 1) indicates the value 1 of the bit (8 - N + 1) of the PAID. Since in Figure 12In the embodiment of (b), there is no increase in the number of bits during the PAID calculation of the terminal. Therefore, the PAID”(8 - N + 1:8) obtained by adding 1 to the PAID(8 - N + 1:8) of the terminal may exist in the BSS. Accordingly, the terminal determines whether the PAID(8 - N + 1:8) of the received frame matches any one of b-i) and b-ii) above. If the PAID(8 - N + 1:8) extracted from the received frame matches any one of b-i) and b-ii), the terminal determines the received frame as an in-BSS frame (S1280). However, if the PAID(8 - N + 1:8) extracted from the received frame does not match any one of b-i) and b-ii), the terminal determines the received frame as an inter-BSS frame (S1282).

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

[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 with the received frame, and it is assumed that the group ID is equal to 63. The terminal uses the PAID value of the received frame and K-bit calculation based on the value of the BSSID of the BSS associated with the terminal to calculate the reference value x' (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 the 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 subtracting the multiplication of the K-bit value based on the BSSID of the BSS associated with the terminal and 2^5 (i.e., y') from the PAID value of the received frame (i.e., (x + y) mod 2^9) in Figure 11 Later, specific embodiments thereof will be described with reference to Figure 14 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 in-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 FIG. illustrates a process of calculating a reference value and a process of calculating a partial AID for in-BSS / inter-BSS frame determination according to an embodiment of the present invention. InFigure 14 In the embodiments, the definitions of each variable are as follows.

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

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

[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 the K-bit value based on the BSSID of the BSS associated with the terminal sending the frame, and y' represents the multiplication of 2^5 and the K-bit value based on the BSSID of the BSS to which the terminal receiving the frame is associated. In Figure 14 the embodiments, x' represents a 9-bit binary value. A separate bin[x', 9] operation can be performed to obtain the binary number x' from the value calculated according to Figure 14 (a) the embodiments.

[0159] First, Figure 14 (a) shows the process of calculating the reference value x' for in-BSS / inter-BSS frame determination. The terminal receiving the frame compares the PAID extracted from the received frame with y'. If PAID - y' is less than 0 (i.e., case RX1), the terminal sets x' to PAID - y' + 2^9. However, if PAID - y' is equal to or greater than 0 (i.e., case RX2), the terminal sets x' to PAID - y'. The terminal can perform in-BSS / inter-BSS frame determination similar to that of Figure 13 the embodiments using the reference value x' calculated in this way.

[0160] Next, Figure 14 (b) shows the process of calculating PAID by the terminal sending the PPDU. Referring to Figure 11 the embodiments, PAID can 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] Thus, according to an embodiment of the present invention, PAID can be calculated as follows. If x + y is equal to or greater than 2^9 (i.e., case TX1), then PAID is set to x + y - 2^9. However, if x + y is less than 2^9 (i.e., case TX2), then PAID is set to x + y.

[0165] When using the reference value x' according to an embodiment of the present invention, the BSS intra / inter-frame determination process of the receiving terminal will be 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 y = y' is satisfied.

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

[0167] According to the equation of case Tx1, PAID - y = x - 2^9 is satisfied. In this case, since x is less than 2^9, PAID - y < 0. Since the values of y and y' are the same, PAID - y' < 0 is satisfied, and the receiving terminal calculates x' according to case Rx1. In this case, x' satisfies the following equation.

[0168] [Equation 3]

[0169] x′ = PAID - y’ + 2^9 = PAID - y + 2^9 = x

[0170] That is, x' = x and x'(8 - N + 1:8) = x(8 - N + 1:8) are satisfied. When assigning the AID of each terminal according to the rules mentioned above, the 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 transmitting terminal calculates PAID through case Tx2

[0172] According to the equation of case Tx2, PAID - y = x is satisfied. In this case, since x is equal to or greater than 0, PAID - y >= 0. Since the values of y and y' are the same, PAID - y' >= 0 is satisfied, and the receiving terminal calculates x' according to case Rx2. In this case, x' satisfies the following equation.

[0173] [Equation 4]

[0174] x′ = PAID - y’ = PAID - y = x

[0175] That is, it satisfies x' = x and x'(8 - N + 1:8) = x(8 - N + 1:8). When assigning the AID of each terminal according to the above rules, the 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 in-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 an inter-BSS frame, since y and y' are determined based on different BSSIDs, the probability that y and y' represent different values is high.

[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. [[ID=eleven]]

[0179] [Equation 5]

[0180] x′ = PAID - y’ + 2^9 = x + y - 2^9 - y’ + 2^9 = x + y - y’ <eleven]]

[0181] Therefore, when y and y' are different, x' and x are different. Since the lower 5 bits of both y and y' are 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 the 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 the 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′

[0196] 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] Meanwhile, 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 of mis - determining an inter - BSS frame as a BSS - internal frame and the probability of mis - determining a BSS - internal frame as an inter - BSS frame. However, according to Figure 13In the method for determining an embodiment, although there is a probability of erroneously determining an inter-BSS frame as an intra-BSS frame, there is no case of erroneously determining an intra-BSS frame as an inter-BSS frame.

[0198] According to another embodiment of the present invention, the terminal may compare the value calculated by using x'(8-N+1:8) and y'(8-N+1:8) with a partial BSS color value (i.e., BCB information) to perform intra / inter-BSS 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 notified 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 notified 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 the ambiguity in PAID value determination, according to Figures 12 to 14 the determination method of the embodiment can be executed. As an example, if the terminal has verified that there is no ambiguity in 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 intra / inter-BSS 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 can identify whether there is ambiguity in PAID value determination. According to an embodiment, if y(5:8-N+1-1) are all 0, the terminal may determine that there is ambiguity, and if not, the terminal may determine that there is no ambiguity. According to another embodiment, if N = 4, the terminal may determine that there is no ambiguity, and if N is any one of 1 to 3, the terminal may determine that there is ambiguity. Here, N represents the number of partial BSS color bits for AID assignment and the number of bits of BSSID information. According to yet another embodiment, the terminal may pass through Figure 15 and Figure 16The method described in determines whether there is ambiguity in PAID value determination.

[0201] Figure 15 Illustrates a non - traditional element format according to another embodiment of the present invention. Among the fields of the non - traditional element in Figure 15 a repetition of the description of the parts that are the same as the fields of the non - traditional element described in Figure 9 will be omitted.

[0202] Referring to Figure 15 , the non - traditional element may include an "Element ID" field, a "Length" field, and a "Partial BSS Color Information" field. Additionally, the "Partial BSS Color Information" field may include a "Number of Partial BSS Color Bits 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 "Number of Partial BSS Color Bits for AID" field, a 4 - bit "Partial BSS Color Bits" field, and a 1 - bit "Ambiguity" field. The "Ambiguity" field signals whether there is ambiguity in PAID value determination through a flag value.

[0203] Figure 16 Illustrates a method of signaling information on 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 "Number of Partial BSS Color Bits for AID" field of the non - traditional element may signal whether the above - mentioned ambiguity can exist. More specifically, the "Number of Partial BSS Color Bits for AID" field may indicate, through a predetermined index, the number of partial BSS color bits for AID assignment and whether ambiguity can exist. For example, indices 1 to 4 may respectively indicate that the number of partial BSS color bits for AID assignment is 1 to 4, and there is no ambiguity. On the other hand, when the number of partial BSS color bits for AID assignment is 4, there may be no ambiguity in PAID value determination. Therefore, indices 5 to 7 may additionally indicate that the number of partial BSS color bits for AID assignment is 1 to 3, and ambiguity may exist.

[0204] Figure 17 Illustrates a second embodiment of the AID assignment method and non - traditional 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, referring to Figure 17 (a), the second embodiment of the AID assignment method according to the present invention can be expressed as Equation 9 below.

[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 in Reference Equation 2, where N is restricted to 4. More specifically, 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 are used to determine the predetermined N bits of the AID. That is, the predetermined N bits of the AID are determined by applying a modulo operation to the sum value 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 the bits from bit 8 - N + 1 to bit 8 of the AID, and N is set to 4. According to the above Figure 1 PAID setting rule, the number of significant bits K based on the value of the BSSID 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, the ambiguity in the determination of 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 - traditional 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 the AID assignment rule that uses the partial BSS color bits. If this field is set to 1, the 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 the embodiment, the number N of partial BSS color bits used for AID assignment is fixed. Therefore, the non - traditional element can indicate whether the partial BSS color is used for AID assignment via the 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 - traditional element may only include the "partial BSS color bit" field without a separate "partial BSS color bit indication" field. When the information of the "partial BSS color bit" field is signaled through the "partial BSS color information" field, the terminal receiving the non - traditional element can recognize that the partial BSS color value is used for AID assignment.

[0212] Figure 18 FIG. illustrates a third embodiment of the AID assignment method according to the present invention. Refer to Figure 18 , the third embodiment of the AID assignment method according to the present invention can be expressed as Equation 10 below.

[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 + 1:431)), 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 the 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 an 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 and the second predetermined N bits of the BSSID. In an 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 corresponding PAID 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 the high N bits of the PAID extracted from the received frame with the partial BSS color advertised to the terminal. If the high N bits of the PAID match the partial BSS color advertised 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 advertised to the terminal, the terminal determines the received frame as an inter-BSS frame.

[0222] Figure 19 FIG. illustrates a fourth embodiment of the AID assignment method according to the present invention. Refer to Figure 18 , the fourth embodiment of the AID assignment method according to the present invention can be expressed as Equation 11 below.

[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])) mod 2^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 according to the rule of Equation 11. According to an embodiment of Equation 11, a 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 value 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 a first predetermined N bits and a second predetermined N bits of the BSSID. In an embodiment of Equation 11, the first predetermined N bits may indicate the bits from bit 44 to bit 44+N-1, and the second predetermined N bits may indicate the bits from bit 40 to bit 40+N-1.

[0227] As described above with reference to Figure 11 it, in the PAID calculation process, the lower 5 bits of y are all set to 0 (i.e., '00000'). In this case, when setting the bits from bit 5 to bit 5+N-1 of the AID according to the rule of Equation 11, PAID(5:5+N-1) is set to a fixed value in the BSS. Therefore, when assigning the AID according to the rule of Equation 11, ambiguity in PAID value determination can be prevented. Moreover, the predetermined bits of PAID, i.e., PAID(5:5+N-1), can have BSS identification ability. 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 BSS-internal frame and BSS-interframe 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 PAID(5:5+N-1) of the received frame matches PAID(5:5+N-1) of the BSS to which the terminal is associated, the terminal determines the received frame as a BSS-internal frame. However, if PAID(5:5+N-1) of the received frame does not match PAID(5:5+N-1) of the BSS to which the terminal is associated, the terminal determines the received frame as a BSS-interframe.

[0228] Figure 20 and 21 FIG. illustrates a fifth embodiment of the AID assignment method according to the present invention. Referring to Figure 20 , a fifth embodiment of the AID assignment method according to the present invention can be expressed as Equation 12 below.

[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 the 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 may indicate the bits from bit 44 to bit 44 + N - 1, and the second predetermined N bits may indicate the bits from bit 40 to bit 40 + N - 1.

[0233] According to the fifth embodiment of the AID assignment method of the present invention, it can also be expressed as shown in Figure 21 and the following Equation 13.

[0234] [Equation 13]

[0235] if (dec(BCB[0:N - 1]) - dec(BSSID[44:44 + N - 1] XOR BSSID[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 BSS | D[40:40 + N - 1])) >= 0

[0238] AID[5:5 + N - 1] = bin[(dec(BCB[0:N - 1]) - dec(BSSID[44:44 + N - 1] XOR BSS}D[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 the value obtained by subtracting the N-bit value based on the BSSID from the partial BSS color value.

[0241] As referred to above Figure 11 stated, during the PAID calculation process, the lower 5 bits of y are all set to 0 (i.e., "00000"). In this case, when setting the bits from bit 5 to bit 5+N-1 of the AID according to the rules of Equations 12 and 13, PAID[5:5+N-1]

[0242] is set to a fixed value in the BSS. Therefore, when assigning the AID according to the rules of Equations 12 and 13, ambiguity in the PAID value determination can be prevented.

[0243] Additionally, if the AID is assigned according to the rules of Equations 12 and 13, at least a part of the K-bit value based on the BSSID (i.e., Figure 11 y in ) is offset by the N-bit value based on the BSSID when setting the PAID according to the embodiment of Equation 1. Therefore, the predetermined bits of the PAID (i.e., PAID[5:5+N-1]) 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 in-BSS frame 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. If the predetermined bits of the PAID match the partial BSS color advertised to the terminal, the terminal determines the received frame as an in-BSS frame. 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.

[0244] In the following, the reason why a predetermined bit of PAID (i.e., PAID[5:5+N-1]) represents a 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 VHT PPDU 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, when AID[0:8] 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]), AID[0:8] is expressed as Equation 14.

[0245] [Equation 14]

[0246] 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) mod 2^9

[0247] (Case a) When dec(BCB[0:N - 1]) - dec(BSSID[44:44 + N - 1] XOR BSSID[40:40 + N - 1])) < 0

[0248] Since 0 <= dec(BCB[0:N-1]) < 2^N, and 0 <= dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1])) < 2^N, AID[5:5+N-1] is determined as follows according to the if condition of Equation 13.

[0249] [Equation 15]

[0250] 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]

[0251] (Case a - 1) When N is not 4

[0252] Substituting Equation 15 into Equation 14 gives the following equation.

[0253] [Equation 16]

[0254] PAID = (dec(AID[0:4]) + (2^N + 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

[0255] Here, based on a part of the value of BSSID, i.e., dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]), is offset (i.e., removed) and the equation can be rearranged as follows.

[0256] [Equation 17]

[0257] 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

[0258] 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].

[0259] (Case a - 2) When N is 4

[0260] When N is 4, dec(BSSID[44:44+N-1] XOR BSSID[40:40+N-1]) in Equation 15 is the same as dec(BSSID[44:47] XOR BSSID[40:43]) in Equation 14. Therefore, substituting Equation 15 into Equation 14 gives the following equation.

[0261] [Equation 18]

[0262] 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

[0263] 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].

[0264] (Case b) When dec(BCB[0:N - 1]) - dec(BSSID[44:44 + N - 1] XOR BSSID[40:40 + N - 1])) > = 0

[0265] 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.

[0266] [Equation 19]

[0267] AID[5:5+N-1]=bin[(dec(BCB[0:N-1])-dec(BSSID[44:44+N-1]XOR BSSID[40:40+N-1])),N]

[0268] (Case b - 1) When N is not 4

[0269] Substituting Equation 19 into Equation 14 yields the following equation.

[0270] [Equation 20]

[0271] PAID=(dec(AlD[0:4])+(dec(BCB[0:N-1])-dec(BSSID[4444+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

[0272] 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

[0273] [Equation 21]

[0274] 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

[0275] 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].

[0276] (Case a - 2) When N is 4

[0277] When N is 4, dec(BSSID[44:44 + N - 1] XOR BSSID[40:40 + N - 1]) in Equation 19 is the same as dec(BSSID[44:47] XOR BSSID[40:43]) in Equation 14. Therefore, substituting Equation 19 into Equation 14 gives the following equation.

[0278] [Equation 22]

[0279] PAID = (dec(AID[0:4]) + (dec(BCB[0:N - 1])) * 2^(5 + N)))) mod 2^9

[0280] Referring to Equation 22, the only factor affecting PAID[5:5 + N - 1] is dec(BCB[0:N - 1] * 2^5). Therefore, PAID[5:5 + N - 1] is equal to BCB[0:N - 1].

[0281] As described above, in all cases, the predetermined bits of PAID, i.e., PAID[5:5 + N - 1], have the same value as the partial BSS color value, i.e., BCB[0:N] - 1].

[0282] Figure 22 FIG. illustrates a third embodiment of a method for determining an intra - BSS frame and an inter - BSS frame according to the present invention. When assigning AID according to Figure 20 and Figure 21 the fifth embodiment shown in Figure 22 the intra - BSS frame and inter - BSS frame determination methods shown in can be used.

[0283] First, the terminal receives a wireless 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.

[0284] 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, as described above in the embodiment of Figure 8 the group ID 0 may indicate that the frame is an uplink frame. In addition, the 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.

[0285] 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 referenced above in Figure 8 it is described that 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 in-BSS frame or an inter-BSS frame based on whether the PAID of the received frame matches BSSID[39:47] of the BSS associated with the terminal. If the PAID matches BSSID[39:47], the terminal determines the received frame as an in-BSS frame (S2232). However, if the PAID does not match BSSID[39:47], the terminal determines the received frame as an inter-BSS frame (S2234).

[0286] 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 a partial BSS color advertised to the terminal (S2240). In this case, the PAID information indicates a predetermined bit of the PAID. In Figure 22In an embodiment, the predetermined bit of the PAID indicates PAID[5:5+N-1]. In addition, the partial BSS color announced to the terminal indicates the partial BSS color announced by the AP associated with the terminal. If an AID is assigned according to the fifth embodiment of the present invention, when the PAID is set, at least a part of the K-bit value based on the BSSID is offset by the N-bit value based on the BSSID. Therefore, the predetermined bit of the PAID (i.e., PAID[5:5+N-1]) represents the partial BSS color announced to the intended recipient of the frame. Therefore, the terminal can determine whether the received frame is an intra-BSS frame or an inter-BSS frame according to whether the predetermined bit of the PAID of the received frame matches the partial BSS color announced to the terminal. If the predetermined bit of the PAID matches the partial BSS color announced to the terminal, the terminal determines the received frame as an intra-BSS frame (S2242). However, if the predetermined bit of the PAID does not match the partial BSS color announced to the terminal, the terminal determines the received frame as an inter-BSS frame (S2244).

[0287] According to an embodiment of the present invention, the intra-BSS frame method and the inter-BSS method when the extracted group ID information is equal to 63 can be executed only when the value of the "number of partial BSS color bits used for AID" field of the non-traditional element 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 method when the extracted group ID information is equal to 63 can be executed only when the "partial BSS color bit indication" field of the non-traditional element 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 using the partial BSS color bit is applied.

[0288] Figure 23 Illustrates the non-traditional element format according to still another embodiment of the present invention. Among the fields of the non-traditional element in Figure 23 the description of the part that is the same as the fields of the non-traditional element described in the above embodiment will be omitted.

[0289] The operations of the HE STA (i.e., non-traditional terminal) of the HE BSS can be controlled by the HT operation element, the VHT operation element, the HE operation element (i.e., non-traditional element), etc. As described above, the non-traditional 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 re-association request frame, the re-association response frame, etc. In addition, the non-traditional element can also be sent via a frame that only contains this element. Refer to Figure 23, the non - traditional elements may include an "Element ID" field, a "Length" field, and a "HE Operation Parameter" field. Additionally, the "HE Operation Parameter" field may include a "BSS Color" field and a "Partial BSS Color Length" field.

[0290] The "BSS Color" field indicates a BSS color value. The BSS color represents the BSS color of the BSS operated by the AP that transmits this element. Additionally, the BSS color may represent the BSS color of the BSS associated with the STA that transmits this element. The "BSS Color" field has a length of 6 bits and may represent the value of an unsigned integer. According to an 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.

[0291] The "Partial BSS Color Length" field may include information related to in - BSS / inter - BSS frame determination for PAID using a VHT PPDU. For example, the "Partial BSS Color Length" field may indicate the number of bits N of the partial BSS color used for AID assignment. The "Partial BSS Color Length" field may perform the same function as the above - mentioned "Number of Partial BSS Color Bits for AID" field. The "Partial BSS Color Length" field may have a length of 3 bits, but the present invention is not limited thereto.

[0292] Figure 24 FIG. illustrates a sixth embodiment of the AID assignment method according to the present invention. Refer to Figure 24 , the sixth embodiment of the AID assignment method according to the present invention can be expressed as the following Equation 23.

[0293] [Equation 23]

[0294] 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]

[0295] Here, N is 4.

[0296] According to the 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 an embodiment of Equation 23, the N bits of a predetermined 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 an embodiment of Equation 23, the first predetermined N bits may indicate the bits from bit 47-N+1 to bit 47, and the second predetermined N bits may indicate the bits from bit 43-N+1 to bit 43.

[0297] As referred to above Figure 11 it is described that 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 of the AID from bit 5 to bit 8 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 the PAID value determination can be prevented.

[0298] In addition, if the AID is assigned according to the rule of Equation 23, when the PAID is set according to an embodiment of Equation 1, the K-bit value based on the BSSID (i.e., Figure 11 y in ) 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]) 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 in-BSS frame 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. In this case, the predetermined bits of the PAID are the value of the predetermined 4 bits of the PAID, i.e., the value of PAID[5:8]. If the predetermined bits of the PAID match the partial BSS color advertised to the terminal, the terminal determines the received frame as an in-BSS frame. 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.

[0299] According to an embodiment of the present invention, since a predetermined bit of the PAID represents a partial BSS color value, a terminal receiving a frame can perform in-BSS frame and inter-BSS frame determination by using the PADI information without obtaining other information or performing other calculations.

[0300] Figure 25 FIG. illustrates a non-conventional element format according to another embodiment of the present invention. In Figure 25 the fields of the non-conventional element in, a repeated description of parts identical to the fields of the non-conventional element described in the above embodiments will be omitted.

[0301] Referring to Figure 25 , the non-conventional element may include an "Element ID" field, a "Length" field, and a "HE Operation Parameter" field. Additionally, 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-conventional element may include a 6-bit "BSS Color" field and a 1-bit "Partial BSS Color Indication" field.

[0302] The "BSS Color" field indicates the BSS color value as described above with reference to Figure 23 . The "Partial BSS Color Bit Indication" field indicates whether the corresponding BSS applies the AID assignment rule using partial BSS color bits. 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. Additionally, the "Partial BSS Color Bit Indication" field may indicate whether to use the intra / inter-BSS frame determination method for frames using the PAID information of the VHT PPDU. According to Figure 24 the embodiment of, the number of bits N of the partial BSS color used for AID assignment is fixed. Therefore, the non-conventional element can indicate whether the partial BSS color is used for AID assignment through a 1-bit "Partial BSS Color Bit Indication" field.

[0303] Figure 26 FIG. illustrates 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 the AID assignment method when N is 4. Here, N represents the number of partial BSS color bits used for AID assignment.

[0304] First, referring 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 Equation 24 below.

[0305] [Equation 24]

[0306] AID[5:8] = bin[(dec(BCB[0:N-1]) * 24 - N + dec(A[0:3-N]) - dec(BSSID[44:47] XOR BSSID[[40:43])) mod 2 4 , 4]

[0307] Here, A[0:3-N] is an arbitrary (3-N+1)-bit binary number.

[0308] Next, referring 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 the following Equation 25.

[0309] [Equation 25]

[0310] AID[5:8] = bin[(dec(BCB[0:3]) - dec(BSSID[44:47] XOR BSSID[40:43])) mod 2 4 , 4]

[0311] 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 the partial BSS color, and the BSSID information indicates the N-bit value based on the BSSID. More specifically, the N-bit value based on the BSSID can be the exclusive OR of the bit values from bit 44 to bit 47 of the BSSID and the bit values from bit 40 to bit 43 of the BSSID.

[0312] If the AID is assigned according to the rules of Equations 24 and 25, when the PAID is set according to the embodiment of Equation 1, the K-bit value based on the BSSID (i.e., Figure 11 y in) 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]) 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 in-BSS frame 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.

[0313] In the following, 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.

[0314] [Equation 26]

[0315] PAID[5:8] = (dec(AID[5:8]) + dec(BSSID[44:47] XOR BSSID[40:43])) mod 2^4

[0316] [Case A] When N is not 4

[0317] When N is not 4, AID[5:8] can be set by the rule of Equation 24. Referring to Equation 24, since A[0:3 - N], AID[5:8] is determined as a variable value. The high N bits of AID[5:8] are determined based on BCB[0:N - 1] to represent the variable value.

[0318] (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

[0319] Substituting Equation 24 into Equation 26 gives the following equation.

[0320] [Equation 27]

[0321] 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

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

[0323] = dec(BCB[0:N - 1]) * 2^(4 - N) + dec(A[0:3 - N])

[0324] 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].

[0325] (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

[0326] Substituting Equation 24 into Equation 26 gives the following equation.

[0327] [Equation 28]

[0328] 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

[0329] = (2A4 + dec(BCB[0:N - 1]) * 2^(4 - N) + dec(A[0:3 - N])) mod 2^4

[0330] = dec(BCB[0:N - 1]) * 2^(4 - N) + dec(A[0:3 - N])

[0331] 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].

[0332] [Case B] When N is 4

[0333] When N is 4, AID[5:8] can be set according to the rule of Equation 25.

[0334] [Case B - 1] When dec(BCB[0:3]) - dec(BSSID[44:47] XOR BSSID[40:43]) >= 0

[0335] Substituting Equation 25 into Equation 26 gives the following equation.

[0336] [Equation 29]

[0337] PAID[5:8] = (dec(BCB[0:3]) - dec(BSSID[44:47] XOR BSSID[40:43]) + dec(BSSID[44:47] XOR BSSID[40:43])) mod 2^4

[0338] = (dec(BCB[0:3])) mod 2^4

[0339] = dec(BCB[0:3])

[0340] Referring to Equation 29, PAID[8 - N + 1:8] is equal to BCB[0:N - 1] (where N is 4).

[0341] [Case B - 2] When dec(BCB[0:3]) - dec(BSSID[44:47] XOR BSSID[40:43]) < 0

[0342] Substituting Equation 25 into Equation 26 gives the following equation.

[0343] [Equation 30]

[0344] PAID[5:8] = (2A4 + dec(BCB[0:3]) - dec(BSSID[44:47] XOR BSSID[40:43]) + dec(BSSID[44:47] XOR BSSID[40:43])) mod 2^4

[0345] = (2^4 + dec(BCB[0:3])) mod 2^4

[0346] = dec(BCB[0:3])

[0347] Referring to Equation 30, PAID[8 - N + 1:8] is equal to BCB[0:N - 1] (where N is 4).

[0348] As described above, in all cases, the predetermined bits of PAID, i.e., PAID[8 - N + 1:8], have the same value as the partial BSS color value, i.e., BCB[0:N - 1].

[0349] Figure 27 FIG. illustrates a fourth embodiment of a method for determining an intra - BSS frame and an inter - BSS frame according to the present invention. When assigning an AID according to the sixth embodiment described with reference to Figure 24 or the seventh embodiment described with reference to Figure 26 the intra - BSS frame and inter - BSS frame determination method shown in Figure 27 can be used.

[0350] First, the terminal receives a wireless 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. Thus, if the received frame is a VHT PPDU, the terminal extracts the group ID and PAID information from the preamble of the VHT PPDU.

[0351] 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. As in 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 through the extracted group ID information.

[0352] 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 referred to above Figure 8 As described, 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 in-BSS frame or an inter-BSS frame based on whether the PAID of the received frame matches BSSID[39:47] of the BSS associated with the terminal. If the PAID matches BSSID[39:47], the terminal determines the received frame as an in-BSS frame (S2732). However, if the PAID does not match BSSID[39:47], the terminal determines the received frame as an inter-BSS frame (S2734).

[0353] 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 a partial BSS color advertised to the terminal (S2740). In this case, the PAID information indicates a predetermined bit of the PAID. In Figure 27 the embodiment, the predetermined bit of the PAID indicates PAID[8 - N + 1:8]. According to an embodiment of the present invention, N = 4. In addition, the partial BSS color advertised to the terminal indicates the partial BSS color advertised 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 bit of the PAID (i.e., PAID[8 - N + 1:8]) represents the partial BSS color advertised to the intended recipient of the frame. Therefore, the terminal can determine whether the corresponding frame is an in-BSS frame or an inter-BSS frame based on whether the predetermined bit of the PAID of the received frame matches the partial BSS color advertised to the terminal. If the predetermined bit of the PAID matches the partial BSS color advertised to the terminal, the terminal determines the received frame as an in-BSS frame (S2742). However, if the predetermined bit of the PAID does not match the partial BSS color advertised to the terminal, the terminal determines the received frame as an inter-BSS frame (S2744).

[0354] According to an embodiment of the present invention, the 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 of the non-conventional element most recently received from the associated AP is not 0. According to another embodiment of the present invention, the 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-conventional 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 using partial BSS color bits is applied.

[0355] Meanwhile, the AID assignment method according to the above embodiment can be applied only when assigning an AID to a VHT STA. The AID assignment candidate values are restricted, and if partial BSS color is used for AID assignment, the number of values that can be designated as an AID is further reduced. Therefore, according to an embodiment of the present invention, the above AID assignment method can be restrictively applied to VHT STAs, thereby ensuring the AID assignment margin for all STAs.

[0356] Although the present invention is described by using wireless LAN communication as an example, the present invention is not limited thereto, and the present invention can be similarly applied to other communication systems such as cellular communication and the like. In addition, although the methods, apparatuses, and systems 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.

[0357] Embodiments of the detailed description of the present invention can be implemented by various means. For example, embodiments of the present invention can be implemented by hardware, firmware, software, and / or a combination thereof.

[0358] In the case of hardware implementation, the method according to an 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, and the like.

[0359] In the case of firmware implementation or software implementation, the method according to an embodiment of the present invention can be implemented by modules, procedures, functions, and the like that perform the operations described above. The software code can be stored in a memory and operated by a processor. The processor can be internally or externally equipped with a memory, and the memory can exchange data with the processor through various publicly known devices.

[0360] The description of the present invention is illustrative, and those skilled in the art will be able to understand that the present invention can be easily modified into other detailed forms without changing the technical idea or its essential features. Therefore, it should be understood that the embodiments described above are illustrative in every sense and not restrictive. For example, each component described as a single type can be implemented distributively, and similarly, components described as distributed can also be implemented in an associated form.

[0361] The scope of the present invention is represented 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 variations or modifications derived from their equivalents fall within the scope of the present invention.

[0362] Industrial Applicability

[0363] 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 basic wireless communication terminal operating a basic service set (BSS), the basic wireless communication terminal comprising: a processor; and a communication unit, wherein the processor is configured to: assign an association ID (AID) of a terminal associated with the basic wireless communication terminal, and send a frame including the AID to the terminal, wherein the frame includes a subfield indicating whether an AID assignment rule is applied to the assignment of the AID, and wherein when the subfield indicates that the AID assignment rule is applied, a predetermined N bits of the AID assigned to the terminal are determined based on a value obtained by subtracting an N-bit value based on the BSSID of the BSS from a partial BSS color bit of the BSS color of the BSS.

2. The basic wireless communication terminal according to claim 1, Among them, wherein the AID assignment rule is related to whether partial BSS color bits are used to assign the AID.

3. The basic wireless communication terminal according to claim 1, Among them, wherein the partial BSS color bits are 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 value of a first predetermined N bits of the BSSID and a second predetermined N bits of the BSSID.

4. The basic wireless communication terminal according to claim 1, Among them, wherein N is 4.

5. The basic wireless communication terminal according to claim 1, Among them, wherein 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] where the BCB is the BSS color, the BSSID is the BSS identifier, and N = 4.

6. The basic wireless communication terminal according to claim 1, Among them, when the basic wireless communication terminal sends a very high throughput (VHT) PHY protocol data unit (PPDU) to the terminal, the processor is configured to: use the AID of the terminal and a K-bit setting based on the BSSID to form a partial AID, and send information of the partial AID by including the information of the partial AID in a preamble of the VHT PPDU.

7. The basic wireless communication terminal according to claim 6, Among them, wherein predetermined bits of the partial AID of the VHT PPDU represent the partial BSS color bits, where the K bits are subtracted by the N-bit value.

8. A wireless communication method for a basic wireless communication terminal operating a basic service set (BSS), the method comprising: assigning an association ID (AID) of a terminal associated with the basic wireless communication terminal, and sending a frame including the AID to the terminal, wherein the frame includes a subfield indicating whether an AID assignment rule is applied to the assignment of the AID, and wherein when the subfield indicates that the AID assignment rule is applied, a predetermined N bits of the AID assigned to the terminal are determined based on a value obtained by subtracting an N-bit value based on the BSSID of the BSS from a partial BSS color bit of the BSS color of the BSS.

9. The wireless communication method according to claim 8, Among them, wherein the AID assignment rule is related to whether partial BSS color bits are used to assign the AID.

10. The wireless communication method according to claim 8, Among them, The partial BSS color bits are 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 the exclusive OR value of a first predetermined N bits of the BSSID and a second predetermined N bits of the BSSID.

11. The wireless communication method according to claim 8, Among them, The N is 4.

12. The wireless communication method according to claim 8, Among them, 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], where the BCB is the BSS color, the BSSID is the BSS identifier, and N = 4.

13. The wireless communication method according to claim 8, Among them, When the basic wireless communication terminal sends a very high throughput VHT PHY protocol data unit PPDU to the terminal, the method further includes: Using the AID of the terminal and a K-bit setting based on the BSSID to set a partial AID; and Sending the information of the partial AID by including the information of the partial AID in the preamble of the VHT PPDU.

14. The wireless communication method according to claim 13, Among them, The predetermined bits of the partial AID of the VHT PPDU represent the partial BSS color bits, where the K bits are subtracted by the N-bit value.

15. A wireless communication terminal, the terminal includes: A processor; And A communication unit, Wherein, the processor is configured to: Receive a frame including the association ID AID of the terminal assigned by a basic wireless communication terminal associated with the terminal, and Perform communication in a basic service set BSS operated by the basic wireless communication terminal by using the AID, Wherein, the frame includes a subfield indicating whether the AID assignment rule is applied to the assignment of the AID, and Wherein, when the subfield indicates that the AID assignment rule is applied, the predetermined N bits of the AID assigned to the terminal are determined based on a value obtained by subtracting the N-bit value based on the BSSID of the BSS from the partial BSS color bits of the BSS color of the BSS.

16. The wireless communication terminal according to claim 15, Among them, The AID assignment rule is related to whether the partial BSS color bits are used to assign the AID.

17. The wireless communication terminal according to claim 15, wherein, The partial BSS color bits are 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 the exclusive OR value of a first predetermined N bits of the BSSID and a second predetermined N bits of the BSSID.

18. The wireless communication terminal according to claim 15, Among them, The N is 4.

19. The wireless communication terminal according to claim 15, wherein 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], where the BCB is the BSS color, the BSSID is the BSS identifier, and N = 4.

20. A wireless communication method of a wireless communication terminal, the method includes: Receive a frame including the association ID AID of the terminal assigned by a basic wireless communication terminal associated with the terminal, and Perform communication in a basic service set BSS operated by the basic wireless communication terminal by using the AID, Wherein, the frame includes a subfield indicating whether the AID assignment rule is applied to the assignment of the AID, and Among them, when the subfield indicates to apply the AID assignment rule, the predetermined N bits of the AID assigned to the terminal are determined based on the value obtained by subtracting the N-bit value based on the BSSID of the BSS from the partial BSS color bits of the BSS color of the BSS.

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