KR102415048B1 - Wireless communication method using aggregate mpdu, and wireless communication terminal using same - Google Patents

Abstract

A wireless communication terminal that communicates wirelessly is disclosed. The wireless communication terminal includes a transceiver; and a processor. The processor transmits an A-MPDU for transmitting a plurality of MPDUs to the receiver using the transceiver.

Description

A wireless communication method using an aggregate MPDU and a wireless communication terminal using the same

The present invention relates to a wireless communication method using an aggregate MPDU and a wireless communication terminal.

Recently, with the spread of mobile devices, a wireless LAN technology that can provide fast wireless Internet services to them has been in the spotlight. Wireless LAN technology is a technology that allows mobile devices such as smart phones, smart pads, laptop computers, portable multimedia players, and embedded devices to wirelessly access the Internet in a home, business, or specific service area based on wireless communication technology in a short distance. to be.

Since IEEE (Institute of Electrical and Electronics Engineers) 802.11 supported an initial wireless LAN technology using a 2.4 GHz frequency, standards for various technologies are being commercialized or developed. First, IEEE 802.11b supports a communication speed of up to 11 Mbps while using a frequency of the 2.4 GHz band. IEEE 802.11a, commercialized after IEEE 802.11b, uses a frequency of 5 GHz band instead of 2.4 GHz band, thereby reducing the influence of interference compared to the fairly crowded 2.4 GHz band, and orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) technology is used to increase the communication speed up to 54 Mbps. However, IEEE 802.11a has a disadvantage in that the communication distance is shorter than that of IEEE 802.11b. And, like IEEE 802.11b, IEEE 802.11g uses a frequency of the 2.4 GHz band to achieve a communication speed of up to 54 Mbps and has received considerable attention as it satisfies backward compatibility. have the upper hand

In addition, IEEE 802.11n is a technical standard established to overcome the limitation on communication speed, which has been pointed out as a weakness in wireless LAN. IEEE 802.11n aims to increase the speed and reliability of the network and extend the operating distance of the wireless network. More specifically, IEEE 802.11n supports high throughput (HT) with a data processing rate of up to 540 Mbps or higher, and uses multiple antennas at both ends of the transmitter and receiver to minimize transmission errors and optimize data rates. It is based on MIMO (Multiple Inputs and Multiple Outputs) technology. In addition, this standard may use a coding method that transmits multiple duplicate copies to increase data reliability.

As the spread of wireless LAN is activated and applications using it are diversified, the need for a new wireless LAN system to support a very high throughput (VHT) higher than the data processing speed supported by IEEE 802.11n has emerged. became Among them, IEEE 802.11ac supports a wide bandwidth (80MHz to 160MHz) at 5GHz frequency. The IEEE 802.11ac standard is defined only in the 5GHz band, but for backward compatibility with existing 2.4GHz band products, the initial 11ac chipsets will also support operation in the 2.4GHz band. Theoretically, according to this standard, the wireless LAN speed of multiple stations is at least 1 Gbps, and the maximum single link speed is at least 500 Mbps. This is achieved by extending the air interface concepts adopted in 802.11n, including wider radio frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256 QAM). In addition, there is IEEE 802.11ad as a method of transmitting data using a 60GHz band instead of the existing 2.4GHz/5GHz. IEEE 802.11ad is a transmission standard that provides a speed of up to 7 Gbps using beamforming technology, and is suitable for high-bit-rate video streaming such as large-capacity data or uncompressed HD video. However, the 60 GHz frequency band has a disadvantage in that it is difficult to pass through obstacles and can only be used between devices in a short distance.

Meanwhile, in recent years, as a next-generation wireless LAN standard after 802.11ac and 802.11ad, discussions are continuing to provide high-efficiency and high-performance wireless LAN communication technology in a high-density environment. That is, in the next-generation wireless LAN environment, high-frequency-efficiency communication must be provided indoors and outdoors in the presence of high-density stations and access points (APs), and various technologies are required to implement it.

In particular, as the number of devices using a wireless LAN increases, it is necessary to efficiently use a predetermined channel. Therefore, there is a need for a technology capable of efficiently using bandwidth by simultaneously transmitting data between a plurality of stations and an AP.

An embodiment of the present invention aims to provide a wireless communication terminal using an aggregate MPDU.

According to an embodiment of the present invention, the wireless communication terminal, which is a receiver for receiving data,

transceiver; and a processor. The processor may transmit an Aggregate-MAC Protocol Data Unit (A-MPDU) including a fragment to the receiver using the transceiver.

The processor may manage the information on the fragment for each combination of a receiver, a traffic identifier (TID), and a sequence number, and create a new fragment based on the information on the fragment.

The information about the fragment may include information about a start pointer indicating a point where fragmentation starts and information about a fragment number.

The processor stores all fragments of the previously generated corresponding MSDU until the last fragment of the MAC service data unit (MSDU) is generated, and based on all the previously generated fragments of the corresponding MSDU You can create a new fragment.

The processor may generate all fragments for any one MSDU within the same transmission opportunity.

The processor may transmit capability information indicating whether a bitmap indicating whether data is received in sequence units can be processed using the transceiver.

The processor may transmit the capability information in a link establishment procedure with the receiver.

A wireless communication terminal for wireless communication according to an embodiment of the present invention includes a transceiver; and a processor. The processor inserts a MAC protocol data unit (MPDU) having a TID corresponding to a primary access category (AC) into an aggregate-MPUD (A-MPDU), and based on the user priority corresponding to the TID, the primary AC An MPDU having a non-primary AC TID, which is a TID different from a TID corresponding to , may be inserted into the A-MPDU, and the A-MPDU may be transmitted to a receiver using the transceiver.

The processor may insert the MPDU having the non-primary AC TID into the A-MPDU based on the maximum number of TIDs that the A-MPDU can have.

The processor may insert the MPDU having the non-primary AC TID into the A-MPDU based on the maximum length that the A-MPDU can have at the corresponding transmission opportunity.

The processor inserts all MPDUs having a TID corresponding to the primary AC stored in the buffer into the A-MPDU, and within the maximum length, corresponding to an AC having a higher user priority than that of the primary AC. An MPDU having the non-primary AC TID may be inserted into the A-MPDU.

The processor may insert a management frame or a control frame into the A-MPDU.

A method of operating a wireless communication terminal for wireless communication according to an embodiment of the present invention is a fragmentation of a MAC protocol data unit (MPDU), an aggregate-MAC service data unit (A-MSDU), or a management protocol data unit (MMPDU) to create a flag generating a comment; and transmitting the A-MPDU including the fragment to the receiver.

managing information about the fragment for each combination of a receiver, a traffic identifier (TID), and a sequence number; and generating a new fragment based on the information about the fragment.

The information about the fragment may include information about a start pointer indicating a point where fragmentation starts and information about a fragment number.

storing all previously generated fragments of the corresponding MSDU until the last fragment of the MSDU is generated; and generating a new fragment based on all fragments of the previously generated corresponding MSDU.

The method may further include generating all fragments for any one MSDU within the same transmission opportunity.

The method may further include transmitting capability information indicating whether a bitmap indicating whether data is received in a sequence unit by using it to process a bitmap.

Transmitting the capability information may include transmitting the capability information in a link establishment procedure with the receiver.

According to an embodiment of the present invention, a method of operating a wireless communication terminal communicating wirelessly includes: inserting an MPDU having a TID corresponding to a primary AC into an Aggregate-MAC Protocol Data Unit (A-MPDU); inserting an MPDU having a non-primary AC TID that is a TID different from the TID corresponding to the primary AC (Access Category) into the A-MPDU based on the user priority corresponding to the TID; and transmitting the A-MPDU to a receiver.

The step of inserting the MPDU having the non-primary AC TID into the A-MPDU may include inserting the MPDU having the non-primary AC TID into the A-MPDU based on the maximum length that the A-MPDU can have at the corresponding transmission opportunity. - It may include the step of inserting into the MPDU.

An embodiment of the present invention provides a wireless communication method using an aggregate MPDU and a wireless communication terminal using the same.

1 shows a wireless LAN system according to an embodiment of the present invention.
2 shows a wireless LAN system according to another embodiment of the present invention.
3 is a block diagram showing the configuration of a station according to an embodiment of the present invention.
4 is a block diagram showing the configuration of an access point according to an embodiment of the present invention.
5 schematically shows a process in which a station establishes a link with an access point according to an embodiment of the present invention.
6 shows a method for a wireless communication terminal to transmit a Block ACK (BA) frame for an Aggregate-MAC Protocol Data Unit (A-MPDU) according to an embodiment of the present invention.
7 shows that a wireless communication terminal transmits an A-MPDU having a plurality of TIDs according to an embodiment of the present invention.
8 shows a format of a Multi-STA Block ACK frame according to an embodiment of the present invention.
9 shows that a wireless communication terminal allocates a sequence number to an MSDU in a dynamic fragmentation operation according to an embodiment of the present invention.
10 shows that a wireless communication terminal allocates a sequence number to an MSDU in a dynamic fragmentation operation according to another embodiment of the present invention.
11 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to an embodiment of the present invention.
12 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to another embodiment of the present invention.
13 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to another embodiment of the present invention.
14 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to another embodiment of the present invention.
15 shows a method for a wireless communication terminal to transmit a Block ACK (BA) frame for an Aggregate-MAC Protocol Data Unit (A-MPDU) according to an embodiment of the present invention.
16 shows that a wireless communication terminal transmits an A-MPDU having a plurality of TIDs according to an embodiment of the present invention.
17 shows a method for a wireless communication terminal to configure a plurality of TID A-MPDUs according to an embodiment of the present invention.
19 and 20 show that the wireless communication terminal according to an embodiment of the present invention transmits an ACK for an A-MPDU including a fragment fragmented to fragmentation level 2.
21 shows an operation of a wireless communication terminal according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Also, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

This application has priority based on Korean Patent Application Nos. 10-2016-0074090 (June 14, 2016), No. 10-2016-0093811 (July 23, 2016) and No. 10-2016-0104407 (Aug. 17, 2016) Claims, and the embodiments and descriptions described in each of the above applications, which are the basis of the priority, are to be included in the detailed description of the present application.

1 illustrates a wireless LAN system according to an embodiment of the present invention. The WLAN system includes one or more basic service sets (BSS), which indicate a set of devices that can communicate with each other by successfully synchronizing. In general, the BSS can be divided into an infrastructure BSS (infrastructure BSS) and an independent BSS (IBSS), and FIG. 1 shows the infrastructure BSS among them.

As shown in FIG. 1 , the infrastructure BSS (BSS1, BSS2) includes one or more stations (STA1, STA2, STA3, STA_4, STA5) and an access point (PCP/AP) that is a station providing a distribution service. -1, PCP/AP-2), and a Distribution System (DS) connecting a plurality of access points (PCP/AP-1, PCP/AP-2).

A station (Station, STA) is an arbitrary device that includes a medium access control (MAC) and a physical layer interface to a wireless medium that comply with the provisions of the IEEE 802.11 standard, and in a broad sense, a non-access point ( Non-AP) stations as well as access points (APs) are included. Also, in this specification, the term 'terminal' may be used as a concept including both a station and a wireless LAN communication device such as an AP. The station for wireless communication includes a processor and a transmit/receive unit, and may further include a user interface unit and a display unit according to an embodiment. The processor may generate a frame to be transmitted through the wireless network or process a frame received through the wireless network, and may perform various other processes for controlling the station. In addition, the transceiver is functionally connected to the processor and transmits and receives a frame through a wireless network for the station.

An access point (AP) is an entity that provides access to a distribution system (DS) via a wireless medium for a station associated with the AP. In the infrastructure BSS, in principle, communication between non-AP stations is performed via the AP, but when a direct link is established, direct communication is also possible between non-AP stations. Meanwhile, in the present invention, the AP is used as a concept including a Personal BSS Coordination Point (PCP), and broadly speaking, a centralized controller, a base station (BS), a Node-B, a BTS (Base Transceiver System), or a site. It may include all concepts such as a controller.

A plurality of infrastructure BSSs may be interconnected through a distribution system (DS). In this case, a plurality of BSSs connected through the distribution system are referred to as extended service sets (ESSs).

2 illustrates an independent BSS that is a wireless LAN system according to another embodiment of the present invention. In the embodiment of Fig. 2, the same or corresponding parts to the embodiment of Fig. 1 will be omitted redundant description.

Since BSS3 shown in FIG. 2 is an independent BSS and does not include an AP, all stations STA6 and STA7 are not connected to the AP. The independent BSS is not allowed to access the distribution system and forms a self-contained network. In the independent BSS, each of the stations STA6 and STA7 may be directly connected to each other.

3 is a block diagram showing the configuration of the station 100 according to an embodiment of the present invention.

As shown, the station 100 according to an embodiment of the present invention may include a processor 110 , a transceiver 120 , a user interface unit 140 , a display unit 150 , and a memory 160 . .

First, the transceiver 120 transmits/receives a wireless signal such as a wireless LAN physical layer frame, and may be built-in or externally provided in the station 100 . According to an embodiment, the transceiver 120 may include at least one transceiver module using different frequency bands. For example, the transceiver 120 may include transceiver modules of different frequency bands, such as 2.4 GHz, 5 GHz, and 60 GHz. According to an embodiment, the station 100 may include a transmission/reception module using a frequency band of 6 GHz or higher and a transmission/reception module using a frequency band of 6 GHz or less. Each transmission/reception module may perform wireless communication with an AP or an external station according to a wireless LAN standard of a frequency band supported by the corresponding transmission/reception module. The transceiver 120 may operate only one transceiver module at a time or operate a plurality of transceiver modules simultaneously according to the performance and requirements of the station 100 . When the station 100 includes a plurality of transmit/receive modules, each transmit/receive module may be provided in an independent form, or a plurality of modules may be integrated into one chip.

Next, the user interface unit 140 includes various types of input/output means provided in the station 100 . That is, the user interface unit 140 may receive a user input using various input means, and the processor 110 may control the station 100 based on the received user input. In addition, the user interface unit 140 may perform an output based on a command of the processor 110 using various output means.

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

The processor 110 of the present invention may execute various commands or programs and process data inside the station 100 . In addition, the processor 110 may control each unit of the above-described station 100 , and may control data transmission/reception between the units. According to an embodiment of the present invention, the processor 110 may execute a program for accessing the AP stored in the memory 160 and receive a communication setting message transmitted by the AP. Also, the processor 110 may read information on the priority condition of the station 100 included in the communication setup message, and request access to the AP based on the information on the priority condition of the station 100 . The processor 110 of the present invention may refer to the main control unit of the station 100, and according to an embodiment, a control unit for individually controlling a part of the station 100, such as the transceiver 120, etc. may point to That is, the processor 110 may be a modulator and/or demodulator that modulates a radio signal transmitted and received from the transceiver 120 . The processor 110 controls various operations of wireless signal transmission and reception of the station 100 according to an embodiment of the present invention. Specific examples thereof will be described later.

The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separated blocks are logically divided into device elements. Accordingly, the elements of the above-described device may be mounted as one chip or a plurality of chips according to the design of the device. For example, the processor 110 and the transceiver 120 may be integrated into one chip or implemented as a separate chip. In addition, in an embodiment of the present invention, some components of the station 100 , such as the user interface unit 140 and the display unit 150 , may be selectively provided in the station 100 .

4 is a block diagram showing the configuration of the AP 200 according to an embodiment of the present invention.

As shown, the AP 200 according to an embodiment of the present invention may include a processor 210 , a transceiver 220 , and a memory 260 . In FIG. 4 , redundant descriptions of parts identical to or corresponding to those of the station 100 of FIG. 3 among the configuration of the AP 200 will be omitted.

Referring to FIG. 4 , the AP 200 according to the present invention includes a transceiver 220 for operating a BSS in at least one frequency band. As described above in the embodiment of FIG. 3 , the transceiver 220 of the AP 200 may also include a plurality of transceiver modules using different frequency bands. That is, the AP 200 according to an embodiment of the present invention may be provided with two or more transmission/reception modules in different frequency bands, for example, 2.4 GHz, 5 GHz, and 60 GHz. Preferably, the AP 200 may include a transmission/reception module using a frequency band of 6 GHz or higher and a transmission/reception module using a frequency band of 6 GHz or less. Each transmission/reception module may perform wireless communication with a station according to a wireless LAN standard of a frequency band supported by the corresponding transmission/reception module. The transceiver 220 may operate only one transceiver module at a time or operate a plurality of transceiver modules simultaneously according to the performance and requirements of the AP 200 .

Next, the memory 260 stores a control program used in the AP 200 and various data corresponding thereto. The control program may include an access program for managing access of stations. In addition, the processor 210 may control each unit of the AP 200 , and may control data transmission/reception between the units. According to an embodiment of the present invention, the processor 210 may execute a program for connection with a station stored in the memory 260 and transmit a communication setting message for one or more stations. In this case, the communication setting message may include information on the access priority condition of each station. In addition, the processor 210 performs connection establishment according to the connection request of the station. According to an embodiment, the processor 210 may be a modulator and/or demodulator that modulates a radio signal transmitted/received from the transceiver 220 . The processor 210 controls various operations of wireless signal transmission and reception of the AP 200 according to an embodiment of the present invention. A specific embodiment thereof will be described later.

5 schematically illustrates a process in which an STA establishes a link with an AP.

Referring to FIG. 5 , the link between the STA 100 and the AP 200 is largely established through three steps of scanning, authentication, and association. First, the scanning step is a step in which the STA 100 acquires access information of the BSS operated by the AP 200 . As a method for performing scanning, a passive scanning method in which information is obtained using only a beacon message S101 periodically transmitted by the AP 200, and a probe request by the STA 100 to the AP There is an active scanning method for transmitting a probe request (S103) and receiving a probe response from the AP (S105) to obtain access information.

The STA 100 successfully receiving the radio access information in the scanning step transmits an authentication request (S107a), receives an authentication response from the AP 200 (S107b), and performs the authentication step do. After the authentication step is performed, the STA 100 transmits an association request (S109a) and receives an association response from the AP 200 (S109b) to perform the association step. In the present specification, association basically means wireless coupling, but the present invention is not limited thereto, and coupling in a broad sense may include both wireless coupling and wired coupling.

Meanwhile, an additional 802.1X-based authentication step (S111) and an IP address acquisition step (S113) through DHCP may be performed. In FIG. 5 , the authentication server 300 is a server that processes 802.1X-based authentication with the STA 100 , and may exist physically coupled to the AP 200 or exist as a separate server.

In a specific embodiment, the AP 200 may be a wireless communication terminal that allocates communication medium resources and performs scheduling in an independent network that is not connected to an external distribution service, such as an ad-hoc network. Also, the AP 200 may be at least one of a base station, an eNB, and a transmission point (TP). Also, the AP 200 may be referred to as a base wireless communication terminal.

A wireless communication terminal according to an embodiment of the present invention may transmit and receive data using a data unit, which is a data processing unit for each layer. Specifically, the wireless communication terminal may generate a MAC protocol data unit (MPDU) in a medium access control (MAC) layer and may generate a physical protocol data unit (PPDU) in a physical layer. In addition, the wireless communication terminal receiving the data may receive the PPDU and obtain the MPDU from the PPDU. Through this operation, the wireless communication terminal can increase the reliability and efficiency of data transmission. For convenience of description, a wireless communication terminal transmitting data is referred to as an originator, and a wireless communication terminal receiving data is referred to as a recipient (recipient). A detailed operation of the sender and the receiver will be described with reference to FIGS. 6 to x.

6 shows an operation in the MAC layer when a wireless communication terminal transmits data according to an embodiment of the present invention.

In the MAC layer, the wireless communication terminal receives a MAC Service Data Unit (MSDU) from the LLC (Logical Link Control) layer. In this case, the wireless communication terminal stores and manages the MAC frame based on the MSDU. The wireless communication terminal generates an MPDU by adding a MAC layer header to the MSDU. Specifically, when the wireless communication terminal acquires a transmission opportunity, the wireless communication terminal may generate an MPDU by adding a MAC header to the MSDU. In this case, the wireless communication terminal may acquire a transmission opportunity through a contention procedure. Specifically, the wireless communication terminal may start a contention procedure for channel access when the wireless medium is in an idle state. In addition, the wireless communication terminal may acquire channel access authority according to a Distributed Coordination Function (DCF)/Enhanced Distributed Channel Access (EDCA) procedure. The wireless communication terminal transmits the MPDU generated in the MAC layer through the PPDU. Specifically, the wireless communication terminal may deliver the MPDU from the MAC layer to the physical layer. The wireless communication terminal may generate a PPDU by adding a physical layer header to the MPDU in the physical layer.

The wireless communication terminal uses a sequence number to manage the transmission of the MSDU. Specifically, the wireless communication terminal allocates a sequence number to each MSDU. In addition, the wireless communication terminal allocates a new sequence number to the MSDU whenever a new MSDU is transmitted. Specifically, whenever the wireless communication terminal transmits a new MSDU, the wireless communication terminal may allocate a sequence number increased by one to the MSDU from the previously allocated sequence number. In this case, the wireless communication terminal may allocate a sequence number for each combination of a receiver address (RA) and a traffic identifier (TID). Specifically, the wireless communication terminal may determine the sequence number of the MAC frame by using a sequence number space (Sequence Number Space, SNS). The wireless communication terminal may generate an MPDU in the MAC layer and determine a sequence number to be assigned to the MSDU by using the SNS. Accordingly, the wireless communication terminal may manage MSDUs having the same RA and the same TID in one sequence number space. Through this operation, the wireless communication terminal can efficiently manage the sequence number assigned to the MSDU.

In addition, the wireless communication terminal manages transmission and retransmission in units of MPDUs. Accordingly, the wireless communication terminal stores the MPDU until it receives the ACK for the MPDU. Specifically, the wireless communication terminal caches the MPDU until it receives the ACK for the MPDU. When the wireless communication terminal receives the ACK for the MPDU, the wireless communication terminal may delete the stored MPDU. In addition, when the wireless communication terminal receives information indicating that the receiver has not received the MPDU, the wireless communication terminal may retransmit the corresponding MPDU. In this case, the ACK and information indicating that the receiver has not received the MPDU may be received through at least one of an ACK frame, a block ACK (BA) frame, and a Multi-STA BA frame. In addition, the wireless communication terminal stores the MSDU in a buffer. The wireless communication terminal deletes the MSDU successfully transmitted to the receiver from the buffer.

In the embodiment of FIG. 5 , the first station STA1 transmits an MSDU having a TID of 2 to a receiver having an RA of 3. In this case, the sequence number value stored by the SNS having an RA of 3 and a TID of 2 of the first station STA1 is 30. Accordingly, the first station STA1 allocates 31, 32, and 33 as sequence numbers to each of the three MSDUs having a TID of 2 for a receiver having an RA of 3. The first station STA1 generates an Aggregate-MPDU (A-MPDU) including three MSDUs. The first station STA1 transmits the generated A-MPDU using the PPDU. The first station STA1 receives a BA frame including a bitmap indicating that MSDUs corresponding to sequence numbers 31 and 33 have been received. Accordingly, the first station STA1 deletes the MSDUs corresponding to sequence numbers 31 and 33 from the cache.

When the size of the MSDU is large, the wireless communication terminal may fragment and transmit the MSDU. This is because, when the size of the MSDU is too large, the probability of transmission failure may increase. In more detail, the wireless communication terminal may fragment and transmit at least one of one MSDU, one Aggregate (A)-MSDU, and one management protocol data unit (MMPDU). For convenience of description, a portion of an MSDU generated through fragmentation, a portion of an A-MSDU, or a portion of an MMPDU is referred to as a fragment.

Specifically, the wireless communication terminal may generate a plurality of fragments by fragmenting at least one of one MSDU, one A-MSDU, and one MMPDU. In this case, the wireless communication terminal may transmit the plurality of generated fragments as a plurality of MPDUs. In addition, the wireless communication terminal that has received the plurality of fragments may acquire at least one of one MSDU, one A-MSDU, and one MMPDU by defragmenting the plurality of fragments. . In this case, the MPDU may be an S-MPDU or an A-MPDU. The wireless communication terminal may generate the remaining fragments except for the last fragment with a fixed size. In addition, the wireless communication terminal may generate a fragment with a non-fixed size. A fragment in which the size of the remaining fragments except for the last fragment is fixed is referred to as a static fragment. A fragment in which the size of a fragment is not fixed is referred to as a dynamic fragmentation. Static fragmentation will be described in detail with reference to FIG. 7 , and static fragmentation will be specifically described with reference to FIG. 8 .

7 shows that a wireless communication terminal according to an embodiment of the present invention transmits data using static fragmentation.

The wireless communication terminal allocates the same sequence number to all fragments obtained by fragmenting the same MSDU. In addition, the wireless communication terminal allocates a fragment number (Fragment Number, FN) to the fragment. Specifically, the wireless communication terminal may fragment the same MSDU and allocate a new fragment number whenever a fragment is generated. The wireless communication terminal may allocate a fragment number for each combination of the same RA, TID, and sequence number. In a specific embodiment, the wireless communication terminal may allocate a fragment number that increases by 1 for each fragment generated from the same MSDU. In this case, the wireless communication terminal may allocate a fragment number from 0 to a fragment. In addition, the wireless communication terminal may generate a fragment when starting the transmission sequence of the MSDU. After transmitting the fragment using the MPDU, the wireless communication terminal stores the fragment. Specifically, the wireless communication terminal may cache the fragment after transmitting the fragment using the MPDU. Through this operation, the wireless communication terminal can classify fragments and efficiently manage the fragments.

The wireless communication terminal may continuously transmit each of a plurality of fragments generated from the same MSDU as one MPDU. This transmission method may be referred to as a fragment burst. In fragment burst transmission, when the wireless communication terminal receives an ACK for a previously transmitted MPDU, it may transmit the next MPDU within a predetermined time from receiving the ACK without returning the transmission opportunity. In this case, the predetermined time may be a Short Inter-Frame Space (SIFS). The wireless communication terminal may repeat this process until it transmits all fragments generated from the same MSDU. In fragment burst transmission, the wireless communication terminal may generate one fragment at a time. Specifically, a fragment may be generated when an ACK for a previously transmitted MPDU is received. In this embodiment, the wireless communication terminal transmits only an MPDU including one fragment at a time, and cannot transmit an A-MPDU for transmitting a plurality of MPDUs. When the wireless communication terminal does not receive the ACK for the previously transmitted MPDU in the fragment burst transmission, the wireless communication terminal returns the transmission opportunity. In this case, the wireless communication terminal may acquire a transmission opportunity again through the contention procedure, and retransmit the MPDU including the previously transmitted fragment. Specifically, the wireless communication terminal may retransmit the MPDU including the stored fragment. In this case, the stored fragment may represent the cached fragment as described above.

In fragment burst transmission, the wireless communication terminal generates a new fragment when receiving the ACK for the previously transmitted MPDU as described above. At this time, the wireless communication terminal assigns a fragment number to a new fragment based on the stored fragment. Specifically, the wireless communication terminal may allocate a number greater than the fragment number of the stored fragment by one as the fragment number of the new fragment. In this case, the wireless communication terminal may allocate 0 as the fragment number of the corresponding fragment when generating the first fragment from the MSDU. In addition, the wireless communication terminal may determine a starting point (starting point) of the MSDU to generate a fragment based on the size of the fragment. The wireless communication terminal creates a fragment and deletes the stored fragment. In this embodiment, the wireless communication terminal may create a new fragment using only the stored fragment and assign a fragment number. Therefore, the wireless communication terminal may not use a tracking space for tracking fragment number assignment and fragment start point.

In the embodiment of FIG. 7 , the first station STA1 fragments one MSDU into four fragments and transmits it. Since the sequence number of the previously transmitted MSDU is 30, the first station STA1 assigns the sequence number of the first fragment 31.0 to 31 and the fragment number to 0. The first station STA1 transmits an MPDU including the first fragment 31.0, and the first station STA1 receives an ACK frame for the MPDU including the first fragment 31.0. The first station STA1 determines the starting point of the second fragment 31.1 based on the cached fragment. Also, since the fragment number of the cached fragment is 0, the first station STA1 assigns the fragment number of the second fragment 31.1 to 1. The first station STA1 transmits an MPDU including the second fragment 31.1, and the first station STA1 receives an ACK frame for the MPDU including the second fragment 31.1. The first station STA1 determines the starting point of the third fragment 31.2 based on the cached fragment. Also, since the fragment number of the cached fragment is 1, the first station STA1 assigns the fragment number of the third fragment 31.2 to 2. The first station STA1 transmits an MPDU including the third fragment 31.2, and the first station STA1 does not receive an ACK frame for the MPDU including the third fragment 31.2. .

Accordingly, the first station STA1 returns a transmission opportunity and acquires a new transmission opportunity through a contention procedure. The first station retransmits the MPDU containing the cached third fragment 31.2. The first station STA1 receives the ACK frame for the MPDU including the third fragment 31.2. The first station STA1 determines the starting point of the fourth fragment 31.3 based on the cached fragment. Also, since the fragment number of the cached fragment is 2, the first station STA1 assigns the fragment number of the third fragment 31.3 to 3 . The first station STA1 transmits the MPDU including the fourth fragment 31.3, and the first station STA1 receives the ACK frame for the MPDU including the fourth fragment 31.3.

8 shows that a wireless communication terminal according to an embodiment of the present invention transmits data using dynamic fragmentation.

As described above, the wireless communication terminal may generate a fragment with a non-fixed size. In addition, the wireless communication terminal may transmit an MPDU including a fragment together with other MPDUs. Specifically, the wireless communication terminal may transmit an MPDU including a fragment and an A-MPDU including another MPDU.

In addition, when dynamic fragmentation is used, the sender generates a fragment according to the fragmentation level and transmits the MPDU including the fragment. In this case, the transmitter may determine the fragmentation level based on the capability of the receiver. In this case, the fragmentation level indicates the degree of fragmentation that the receiver can receive. The fragmentation level can be divided into four levels. Level 0 may indicate that the wireless communication terminal does not support dynamic fragmentation of the MSDU received. In addition, level 1 may indicate that the wireless communication terminal can receive the MPDU including one fragment. In this case, the MPDU may be a single MPDU that is not aggregated with other MPDUs or an MPDU other than an A-MPDU. In addition, level 2 may indicate that the wireless communication terminal may receive an A-MPDU including one fragment per MSDU. Specifically, level 2 may indicate that the wireless communication terminal may receive an A-MPDU including one or less fragments per MSDU. Level 3 may indicate that the wireless communication terminal may receive an A-MPDU including a plurality of fragments for each MSDU. Specifically, level 3 may indicate that the wireless communication terminal can receive an A-MPDU including 4 or less fragments per MSDU. The sender and the receiver may signal information about the fragmentation level in the link setup procedure. In addition, the sender and the receiver may negotiate information about the fragmentation level in the ADDBA procedure. This will be described in detail with reference to FIGS. 15 to 20 .

In the embodiment of FIG. 8 , the receiver supports fragmentation level 3 . In the embodiment of FIG. 7( a ), the sender fragments the MSDU in fragmentation level 2 . Accordingly, the sender transmits an A-MPDU including fragments of different MSDUs one by one to the receiver. In this case, the A-MPDU is the first fragment (6.0) of the MSDU corresponding to sequence number 6, the first fragment (7.0) of the MSDU corresponding to sequence number 7, and the first fragment of the MSDU corresponding to sequence number 8. It includes a fragment (8.0), a first fragment (9.0) of an MSDU corresponding to sequence number 9, and a first fragment (10.0) of an MSDU corresponding to sequence number 10. In the embodiment of FIG. 7( b ), the sender fragments the MSDU in fragmentation level 3 . Accordingly, the sender transmits an A-MPDU including one or more fragments of different MSDUs to the receiver. In this case, the A-MPDU is the first fragment (6.0) of the MSDU corresponding to the sequence number 6, the first fragment (7.0) and the second fragment (7.1) of the MSDU corresponding to the sequence number 7, and the sequence It includes the first fragment (8.0) and the second fragment (8.1) of the MSDU corresponding to number 8.

9 shows that a wireless communication terminal allocates a sequence number to an MSDU in a dynamic fragmentation operation according to an embodiment of the present invention.

As described with reference to FIG. 7 , the wireless communication terminal may allocate a new sequence number to the MSDU whenever a new MSDU is transmitted. Specifically, whenever the wireless communication terminal transmits a new MSDU, the wireless communication terminal may allocate a sequence number increased by one to the MSDU from the previously allocated sequence number. When the sender uses static fragmentation, the sender transmits one fragment at a time, transmits all fragments for one MSDU, and then transmits a new fragment. Therefore, when the wireless communication terminal uses static fragmentation, it is not a problem for the wireless communication terminal to insert a sequence number corresponding to the fragment into the fragment based on the stored fragment. However, when the wireless communication terminal uses dynamic fragmentation, the wireless communication terminal may allocate the same sequence number to fragments of different MSDUs.

In the embodiment of FIG. 9 , the first station STA1 sends the first MSDU 6.0 corresponding to sequence number 6, MSDU 7.0 corresponding to sequence number 7, and MSDU corresponding to sequence number 8 to at least one receiver. An A-MPDU including the th fragment (8.0) is transmitted. The first station STA1 receives, from at least one receiver, an MSDU corresponding to sequence number 6 (6.0), an MSDU corresponding to sequence number 7 (7.0), and a first fragment of an MSDU corresponding to sequence number 8 (8.0). Receives a BA frame indicating that it has been received.

The first station STA1 transmits an A-MPDU including an MSDU corresponding to sequence number 8 and another MSDU, and a second fragment 8.1 of the MSDU corresponding to sequence number 8. At this time, since the first station STA1 failed to transmit all the fragments of the MSDU corresponding to the sequence number 8, the previous sequence number managed by the SNS is maintained as 7. Accordingly, the first station STA1 allocates 8 as a sequence number to an MSDU corresponding to the sequence number 8 and another MSDU. The receiver determines whether the MSDU is duplicated based on the sequence number and the fragment number. Therefore, in the case of FIG. 9 , the receiver may determine that a duplicate MSDU has been received even though a new MSDU has been received, and may transmit an ACK for the corresponding MSDU to the sender and not deliver the corresponding MSDU to a higher layer.

10 shows that a wireless communication terminal allocates a sequence number to an MSDU in a dynamic fragmentation operation according to another embodiment of the present invention.

When the wireless communication terminal generates the first MPDU including the fragment of the MSDU, the wireless communication terminal may increment the sequence number of the previous MSDU. Specifically, when the wireless communication terminal generates the first MPDU including the fragment of the MSDU, the wireless communication terminal may increase the previous sequence number managed by the SNS by one.

In the embodiment of FIG. 10 , the first station STA1 provides to at least one receiver the first MSDU 6.0 corresponding to sequence number 6, MSDU 7.0 corresponding to sequence number 7, and MSDU corresponding to sequence number 8. An A-MPDU including the th fragment (8.0) is transmitted. The first station STA1 receives, from at least one receiver, an MSDU corresponding to sequence number 6 (6.0), an MSDU corresponding to sequence number 7 (7.0), and a first fragment of an MSDU corresponding to sequence number 8 (8.0). Receives a BA frame indicating that it has been received.

The first station STA1 transmits an A-MPDU including an MSDU 9.0 corresponding to sequence number 9 and a second fragment 8.1 of the MSDU corresponding to sequence number 8. When the first station STA1 transmits the first MSDU of the MSDU corresponding to the sequence number 8, the first station STA1 sets the previous sequence number managed by the SNS to 8. Accordingly, the first station STA1 may allocate 9 to a new MSDU even though it has not transmitted all of the fragments of the MSDU corresponding to the sequence number 8.

11 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to an embodiment of the present invention.

When the wireless communication terminal uses static fragmentation, the wireless communication terminal may determine a fragmentation start pointer for the MSDU based on the last transmitted fragment. In this case, the fragmentation start pointer indicates a point at which fragmentation for a corresponding fragment starts in the MSDU. This is because the size of the remaining fragments except for the last fragment is fixed. In particular, when the fragment number increases from 0 to 1, the wireless communication terminal may determine a fragmentation start pointer for the MSDU based on the fragment number of the last transmitted fragment. However, when the wireless communication terminal uses dynamic fragmentation, the wireless communication terminal may not be able to determine a fragmentation start pointer for the MSDU based on the fragment number of the last transmitted fragment.

11, the first station STA1 transmits an A-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and a fragment having a TID of 2 to at least one receiver do. At this time, the sequence numbers of each of the two MSDUs 6.0 and 7.0 having a TID of 1 are 6 and 7. One fragment (8.0) having a TID of 1 has a sequence number of 8 and a fragment number of 0. Also, the sequence number of one MSDU 31.0 having a TID of 2 is 31. One fragment 32.0 having a TID of 2 has a sequence number of 32 and a fragment number of 0. The first station STA1 receives, from the receiver, two MSDUs and fragments having a TID of 1, and a BA frame indicating an ACK for one MSDU and fragments having a TID of 2.

When the first station STA1 transmits the remaining fragment of an MSDU with a TID of 1 and a sequence number of 8 or transmits the remaining fragment of an MSDU with a TID of 2 and a sequence number of 32, the first station STA1 does not know the start pointer of each MSDU. Also, the first station SAT1 does not know which fragment number to be assigned to a fragment to be transmitted.

12 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to another embodiment of the present invention.

The wireless communication terminal may manage fragment-related information for each combination of a receiver, a TID, and a sequence number. In addition, the wireless communication terminal may generate a new fragment based on information related to the fragment. Specifically, the wireless communication terminal may determine a fragmentation start pointer of a new fragment based on information related to the fragment. In addition, the wireless communication terminal may allocate a fragment number to a new fragment based on information related to the fragment. In this case, the fragment-related information may be at least one of information about a fragment number and information about a fragmentation start pointer. Specifically, when the wireless communication terminal uses dynamic fragmentation, the wireless communication terminal may manage information about a fragment number and information about a fragmentation start pointer. In a specific embodiment, the wireless communication terminal may store the fragment number of the last transmitted fragment. In addition, the wireless communication terminal may store the sum of sizes of previously generated fragments. In addition, the wireless communication terminal may store information about the fragmentation number and information about the fragmentation start pointer in the form of a tuple. In a specific embodiment, the wireless communication terminal may use a fragment number space (FNS) that manages information about a fragment number and information about a fragment start pointer. Specifically, FNS may be defined as shown in the following table.

When the wireless communication terminal generates the last fragment of the corresponding MSDU, the wireless communication terminal may delete the FNS for the corresponding MSDU or a tuple including information about the fragment of the corresponding MSDU.

12, the first station STA1 transmits an A-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and a fragment having a TID of 2 to at least one receiver do. At this time, the sequence numbers of each of the two MSDUs 6.0 and 7.0 having a TID of 1 are 6 and 7. One fragment (8.0) having a TID of 1 has a sequence number of 8 and a fragment number of 0. Also, the sequence number of one MSDU 31.0 having a TID of 2 is 31. One fragment 32.0 having a TID of 2 has a sequence number of 32 and a fragment number of 0. The first station STA1 receives, from the receiver, two MSDUs and fragments having a TID of 1, and a BA frame indicating an ACK for one MSDU and fragments having a TID of 2.

The first station STA1 maintains the first FNS and the second FNS. In this case, the first FNS stores information for fragment transmission in which the TID for the first receiver is 1 and the sequence number is 8. Specifically, the first FNS is the sum of the size of the fragment with the TID of 1 and the sequence number of 8 transmitted to the first recipient, and the fragment of the fragment with the TID of 1 and the sequence number of 8 finally transmitted to the first recipient. Store the fragment number (0). In addition, the second FNS stores information for transmission of a fragment having a TID of 2 and a sequence number of 32 for the second receiver. Specifically, the second FNS is the sum of the size of the fragment with TID 2 and sequence number 32 transmitted to the second recipient and the fragment of the fragment with TID 2 and sequence number 32 finally transmitted to the second recipient. Store the fragment number (0). Accordingly, the first station STA1 determines a fragmentation start pointer of a fragment having a TID of 1 and a sequence number of 8 for the first receiver based on the first FNS. Also, the first station STA1 allocates 1 as a fragment number to a fragment having a TID of 1 and a sequence number of 8 for the first receiver based on the first FNS. Accordingly, the first station STA1 determines a fragmentation start pointer of a fragment having a TID of 2 and a sequence number of 32 for the second receiver based on the second FNS. Also, the first station STA1 allocates 1 as a fragment number to a fragment having a TID of 2 and a sequence number of 32 for the second receiver based on the second FNS.

13 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to another embodiment of the present invention.

In another specific embodiment, the wireless communication terminal may store all previously generated fragments of the corresponding MSDU until the last fragment of the MSDU is generated. Specifically, the wireless communication terminal may cache all fragments of the previously generated MSDU until the last fragment of the MSDU is generated. The wireless communication terminal may generate a new fragment based on the stored fragment. Specifically, the wireless communication terminal may determine a fragmentation start pointer of a new fragment based on the stored fragment. In addition, the wireless communication terminal may allocate a fragment number to a new fragment based on the stored fragment. Specifically, the wireless communication terminal may store the MPDU including all fragments of the previously generated MSDU until the last fragment of the MSDU is generated. To this end, the wireless communication terminal may transmit a BAR frame requesting a BA frame to the receiver only for the MSDU in which all fragments have been transmitted. This is because the wireless communication terminal can store the MPDU until it receives an ACK from the receiver.

13, the first station STA1 transmits an A-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and a fragment having a TID of 2 to at least one receiver do. At this time, the sequence numbers of each of the two MSDUs 6.0 and 7.0 having a TID of 1 are 6 and 7. One fragment (8.0) having a TID of 1 has a sequence number of 8 and a fragment number of 0. Also, the sequence number of one MSDU 31.0 having a TID of 2 is 31. One fragment 32.0 having a TID of 2 has a sequence number of 32 and a fragment number of 0. The first station STA1 receives, from the receiver, two MSDUs and fragments having a TID of 1, and a BA frame indicating an ACK for one MSDU and fragments having a TID of 2.

At this time, since the first station STA1 did not transmit all fragments of the MSDU having a TID of 1 and a sequence number of 8 and all fragments of an MSDU having a TID of 2 and a sequence number of 32, the TID is 1 and Fragments with sequence number 8 and fragments with TID 2 and sequence number 32 are cached. Accordingly, the first station STA1 determines a fragment start pointer of a fragment having a TID of 1 and a sequence number of 8 based on the cached fragment. Also, the first station STA1 allocates 1 as a fragment number to a fragment having a TID of 1 and a sequence number of 8 based on the cached fragment. Also, the first station STA1 determines a fragmentation start pointer of a fragment having a TID of 2 and a sequence number of 32 for the second recipient based on the cached fragment. Also, the first station STA1 allocates 1 as a fragment number to a fragment having a TID of 2 and a sequence number of 32 based on the cached fragment. Through this embodiment, the wireless communication terminal can efficiently manage information on fragments without additional information storage.

14 shows allocating a fragment number to a fragment in a dynamic fragmentation operation of a wireless communication terminal according to another embodiment of the present invention.

In another specific embodiment, the wireless communication terminal may generate all fragments of any one MSDU together. Specifically, the wireless communication terminal may generate all fragments of any one MSDU in one transmission opportunity.

14, the first station STA1 transmits an A-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and a fragment having a TID of 2 to at least one receiver do. At this time, the sequence numbers of each of the two MSDUs 6.0 and 7.0 having a TID of 1 are 6 and 7. One fragment (8.0) having a TID of 1 has a sequence number of 8 and a fragment number of 0. Also, the sequence number of one MSDU 31.0 having a TID of 2 is 31. One fragment 32.0 having a TID of 2 has a sequence number of 32 and a fragment number of 0. The first station STA1 receives, from the receiver, two MSDUs and fragments having a TID of 1, and a BA frame indicating an ACK for one MSDU and fragments having a TID of 2.

In this case, the first station STA1 generates three fragments of an MSDU having a TID of 1 and a sequence number of 8 together in one transmission opportunity. However, as described above, the first station STA1 transmits only one fragment 8.0 and transmits the remaining two fragments 8.1 and 8.2 at the next transmission opportunity. Also, the first station STA1 generates three fragments of an MSDU having a TID of 2 and a sequence number of 32 together in one transmission opportunity. However, as described above, the first station STA1 transmits only one fragment 32.0 and transmits the remaining two fragments 32.1 and 32.2 at the next transmission opportunity. The wireless communication terminal can efficiently manage information about fragments without storing additional information or caching fragments through this embodiment.

15 shows a method for a wireless communication terminal to transmit a Block ACK (BA) frame for an Aggregate-MAC Protocol Data Unit (A-MPDU) according to an embodiment of the present invention.

The wireless communication terminal may generate one A-MPDU by combining a plurality of MPDUs. The wireless communication terminal may transmit the generated A-MPDU. The legacy wireless communication terminal generates an A-MPDU by combining only MPDUs having the same traffic identifier (TID). A wireless communication terminal according to an embodiment of the present invention may generate one A-MPDU by combining a plurality of MPDUs having different TIDs. For convenience of description, an A-MPDU including a plurality of MPDUs corresponding to a plurality of different TIDs is defined as a multi-TID A-MPDU (Multi-TID A-MPDU) or an A-MPDU having a plurality of TIDs (A-MPDU). with Multiple TIDs). The wireless communication terminal can increase A-MPDU transmission efficiency through this. Specifically, the wireless communication terminal may transmit an A-MPDU having a plurality of TIDs by using a HE PPDU (Physical Layer Protocol Data Unit). In this case, the HE PPDU may be a HE MU (Multi User) PPDU. Also, the HE PPDU may be an HE trigger-based PPDU.

The wireless communication terminal may set parameters related to A-MPDU and BA frame transmission in a link setup procedure. The wireless communication terminal may set parameters related to A-MPDU transmission having a plurality of TIDs in a link establishment procedure. Specifically, the wireless communication terminal may transmit information on the maximum number of TIDs indicating the maximum number of TIDs that the wireless communication terminal can simultaneously receive in the link establishment procedure. In this case, the wireless communication terminal may transmit information on the maximum number of TIDs using the HE capability information element, which is information indicating the capability of the terminal. This is because, as the number of TIDs of an A-MPDU having a plurality of TIDs increases, a high processing capability of the wireless communication terminal receiving the A-MPDU may be required. The maximum number of TIDs information may be a maximum number of TID field of the HE capability information element. The information on the maximum number of TIDs that the AP transmits to a non-AP wireless communication terminal is the maximum TID that an MPDU included in an uplink (UL) A-MPDU transmitted by a wireless communication terminal other than the AP can have. number can be indicated. In addition, information on the maximum number of TIDs transmitted by a wireless communication terminal other than the AP to the AP may indicate the maximum number of TIDs that a DownLink (DL) A-MPDU transmitted by the AP can have. In the link establishment procedure, the wireless communication terminal may transmit information on the maximum number of TIDs using a management frame. In this case, the management frame includes a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, It may be at least one of an association response frame and a beacon frame. In addition, when the AP transmits information on the maximum number of TIDs using a beacon frame, the information on the maximum number of TIDs may indicate the number of TIDs that the AP can simultaneously receive. Specifically, when the AP transmits information on the maximum number of TIDs using a beacon frame, the information on the maximum number of TIDs is not the maximum number of TIDs that an MPDU included in an A-MPDU that any one wireless communication terminal transmits to the AP, but the MU. It may indicate the maximum number of TIDs allowed for transmission in UL transmission. This is because the AP transmits the beacon frame to all wireless communication terminals of the BSS operated by the AP. In another specific embodiment, information on the maximum number of TIDs of a beacon frame may be used for other purposes. In another specific embodiment, the maximum number of TID field of the beacon frame may be a reserved field.

In the link establishment procedure, the wireless communication terminal may receive an All ACK from the receiver and transmit an All ACK capable indicator indicating whether the All ACK can be processed. In this case, the All ACK is an ACK indicating that the receiver has received an A-MPDU transmitted by any one transmitter or all MPDUs included in the multiple TID A-MPDU. When the All ACK is transmitted, the sender cannot know information about the fragment transmitted from the All ACK. In order to process All ACK, the sender must store information about the fragment transmitted by the sender. This is because, depending on the capability of the sender, information on the fragment transmitted by the sender may not be stored. Specifically, the wireless communication terminal may transmit an All ACK capable indicator indicating whether All ACK can be processed using the HE capability information element. A plurality of TID A-MPDUs will be described with reference to FIG. 16 .

The wireless communication terminal may fragment and transmit at least one of one MAC service data unit (MSDU), one Aggregate (A)-MSDU, and one management protocol data unit (MMPDU). For convenience of description, a portion of an MSDU generated through fragmentation, a portion of an A-MSDU, or a portion of an MMPDU is referred to as a fragment. In addition, a wireless communication terminal transmitting data is referred to as an originator, and a wireless communication terminal receiving data is referred to as a recipient (recipient).

Specifically, the wireless communication terminal may generate a plurality of fragments by fragmenting at least one of one MSDU, one A-MSDU, and one MMPDU. In this case, the wireless communication terminal may transmit the plurality of generated fragments as a plurality of MPDUs. In addition, the wireless communication terminal that has received the plurality of fragments may acquire at least one of one MSDU, one A-MSDU, and one MMPDU by defragmenting the plurality of fragments. . In this case, the MPDU may be an S-MPDU or an A-MPDU.

The receiver needs sufficient buffer capacity and processing power to defragment multiple fragments. Specifically, the receiver must store all the fragments until receiving all the fragments of the MSDU corresponding to the same sequence number. Therefore, when the receiver supports the necessary capabilities for receiving the fragment, the sender can send the fragment to the receiver. After all, the sender needs to know the fragmentation level supported by the receiver. The wireless communication terminal may signal about the fragmentation level. Specifically, the wireless communication terminal transmits information about the fragmentation level of the fragment that the wireless communication terminal can receive in the link establishment procedure with the AP, and the fragmentation of the fragment that the AP can receive. You can receive information about the level. Specifically, the wireless communication terminal may transmit information about the fragmentation level using the HE Capability information element. In this case, the HE Capability information element may indicate the capability of the wireless communication terminal. In addition, the wireless communication terminal includes a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, and an association response. response) frame may be used to transmit information about the fragmentation level.

As described above, the HE capability information element may include a Max number of TID field, an All ACK capable indicator, and information indicating a fragmentation level supported by the wireless communication terminal (Fragmentation support level). A specific format of the HE capability information element may be the same as in the embodiment of FIG. 15 .

In addition, the wireless communication terminal may set the BA parameter in an Add Block ACK (ADDBA) procedure. In this case, the BA parameter is a parameter used for BA frame transmission and BA frame reception. The wireless communication terminal may request the ACK in the form of a BA frame using the ADDBA request frame. In addition, the wireless communication terminal may transmit a response to the ADDBA request frame using the ADDBA response frame. The ADDBA request frame and the ADDBA response frame may include a Block Ack Parameter Set element. In this case, the Block Ack Parameter Set element includes information about the BA parameter. In addition, the wireless communication terminal may set the BA parameter for each TID. Specifically, the wireless communication terminal may negotiate BA parameter settings for each TID. In a specific embodiment, the wireless communication terminal may use the TID field included in the Block Ack Parameter Set element to designate a TID, which is a target of BA parameter setting negotiation. The sender may request BA parameter setting by sending an ADDBA request frame. The receiver may receive the ADDBA request frame and confirm the BA parameter setting by transmitting an ADDBA response frame to the ADDBA request frame. When the sender receives the ADDBA response frame and transmits an ACK frame for the ADDBA response frame, the sender and the receiver may set BA parameters.

The wireless communication terminal may transmit buffer size information indicating the number of MPDUs that can be stored until transmitting the BA frame after receiving data in the ADDBA procedure. Specifically, the wireless communication terminal may transmit buffer size information using the Block Ack Parameter Set element in the ADDBA procedure. The wireless communication terminal may set the length of the BA bitmap based on the range of values that the buffer size information may have. Specifically, when the range of values that the buffer size information can have is between 1 and X, the wireless communication terminal may set the length of the BA bitmap to X bits. In this case, when the wireless communication terminal does not receive information on the length of the BA bitmap, the wireless communication terminal may set the length of the BA bitmap to X bits. A specific format of the Block Ack Parameter Set element may be the same as in the embodiment of FIG. 15 .

When the AP transmits downlink to the wireless communication terminal, the AP may transmit the A-MPDU based on the capability of the wireless communication terminal signaled in the link establishment procedure and the BA parameter set in the ADDBA procedure. In this case, the wireless communication terminal may transmit a BA frame or a Multi-STA Block ACK (M-BA) frame to the AP based on the capability of the AP and the BA parameter set in the ADDBA procedure. A specific format of the BA frame will be described with reference to FIG. 18 .

When the AP simultaneously receives A-MPDUs from a plurality of wireless communication terminals, it may be difficult to store the plurality of MPDUs received by the AP in a buffer and maintain a score board. In this case, the scoreboard indicates information in which the AP records the reception state of each MPDU. Accordingly, the AP may indicate the maximum number of TIDs that each of the wireless communication terminals can have in the A-MPDU to be transmitted by using the trigger frame. Specifically, the AP may indicate the maximum TID to be transmitted by each wireless communication terminal by using the User Info field of the trigger frame. In this case, the wireless communication terminal receiving the trigger frame may set the number of TIDs that the A-MPDU may have based on the trigger frame. Specifically, the wireless communication terminal receiving the trigger frame may set the number of TIDs included in the A-MPDU to be transmitted based on the maximum number of TIDs indicated by the trigger frame, and transmit the A-MPDU to the AP. For example, the wireless communication terminal receiving the trigger frame may set the number of TIDs included in the A-MPDU to be transmitted not exceeding the maximum number of TIDs indicated by the trigger frame, and transmit the A-MPDU to the AP.

In addition, when the wireless communication terminal uses the HE MU PPDU in single user (SU) uplink (UL) transmission, the wireless communication terminal may be restricted from transmitting A-MPDUs having a plurality of TIDs. A wireless communication terminal may use a relatively wide transmission range in a narrow frequency band by using the HE MU PPDU in SU UL transmission. In this case, if a wireless communication terminal is allowed to transmit an A-MPDU including an A-MPDU having a plurality of TIDs, an issue of equity may occur in terms of contention with other wireless communication terminals. Accordingly, when the wireless communication terminal uses the HE MU PPDU in SU UL transmission, the wireless communication terminal may be restricted from transmitting the A-MPDU having a plurality of TIDs.

16 shows that a wireless communication terminal transmits an A-MPDU having a plurality of TIDs according to an embodiment of the present invention.

When the wireless communication terminal transmits the HE trigger-based PPDU or transmits the HE MU PPDU in DL MU transmission, the wireless communication terminal may transmit a plurality of TID A-MPDUs. In addition, the wireless communication terminal may transmit a plurality of TID A-MPDUs according to certain conditions even in SU transmission. Specifically, the wireless communication terminal may transmit a plurality of TID A-MPDUs using the HE MU PPDU. Also, the wireless communication terminal may set the number of TIDs of the plurality of TID A-MPDUs based on the above-described maximum number of TIDs. In more detail, the wireless communication terminal may set the number of TIDs of the plurality of TID A-MPDUs within the maximum number of TIDs indicated by the maximum number of TIDs information. In uplink transmission, the wireless communication terminal may obtain information on the maximum number of TIDs from the association response frame or the authentication response frame. In addition, in downlink transmission, the wireless communication terminal may obtain information on the maximum number of TIDs from the association request frame or the authentication request frame.

In the embodiment of FIG. 16( a ), a wireless communication terminal other than the AP transmits a plurality of TID A-MPDUs to the AP in UL SU transmission. In this case, the wireless communication terminal other than the AP acquires the HE Capability information element from the association response (Assoc. resp.) frame. In addition, the wireless communication terminal other than the AP acquires information on the maximum number of TIDs from the Max number of TID field of the HE Capability information element. In this case, the information on the maximum number of TIDs is 4. Accordingly, the wireless communication terminal other than the AP transmits a plurality of TID A-MPDUs having 4 or less TIDs to the AP.

In the embodiment of FIG. 16( b ), the AP transmits a plurality of TID A-MPDUs to a wireless communication terminal other than the AP in DL SU transmission. At this time, the AP acquires the HE Capability information element from the association request (Assoc. req.) frame. In addition, the AP acquires the maximum number of TIDs of 4 from the Max number of TID field of the HE Capability information element. Accordingly, the AP transmits a plurality of TID A-MPDUs having 4 or less TIDs to a wireless communication terminal other than the AP.

17 shows a method for a wireless communication terminal to configure a plurality of TID A-MPDUs according to an embodiment of the present invention.

The wireless communication terminal aggregates the MPDUs stored in the EDCA queue to generate an A-MPDU. At this time, the wireless communication terminal determines an MPDU having a TID corresponding to the primary AC based on the maximum length that the A-MPDU can have at the corresponding transmission opportunity, and a non-primary (TID that is different from the TID corresponding to the primary AC) Non-Primary) A-MPDUs may be generated by aggregating MPDUs having AC TIDs. Specifically, the wireless communication terminal inserts all MPDUs having a TID corresponding to the primary AC stored in the buffer into the A-MPDU, and inserts the non-primary AC TID within the maximum length that the A-MPDU can have at the corresponding transmission opportunity. MPDU can be inserted. In a specific embodiment, the wireless communication terminal may insert the MPDU having the non-primary AC TID into the A-MPDU based on the user priority corresponding to the TID. In addition, the primary AC may indicate the AC of the MPDU for which the transmission opportunity has been obtained. For example, the wireless communication terminal may generate an A-MPDU by aggregating an MPDU having a TID corresponding to the primary AC and an MPDU having a non-primary AC TID corresponding to an AC having a higher user priority than the primary AC. have.

In addition, the wireless communication terminal may generate an A-MPDU by aggregating an MPDU having a TID corresponding to the primary AC and at least one of a management frame and a control frame. Specifically, the wireless communication terminal may insert at least one of the management frame and the control frame into the A-MPDU, and insert the MPDU having the TID corresponding to the primary AC into the A-MPDU. In another specific embodiment, the wireless communication terminal inserts the MPDU having the TID corresponding to the primary AC into the A-MPDU, and inserts at least one of the management frame and the control frame after the MPDU having the TID corresponding to the primary AC. It can be transmitted by inserting it into the A-MPDU in order of priority. In addition, the wireless communication terminal collects MPDUs having a TID corresponding to the primary AC, a management frame/control frame, and an MPDU having a non-primary AC TID corresponding to an AC having a higher user priority than the primary AC, MPDU can be generated. Specifically, the wireless communication terminal preferentially inserts a management frame or a control frame into the A-MPDU, and inserts an MPDU having a TID corresponding to the primary AC and an MPDU having a non-primary AC TID into the A-MPDU. can At this time, as described above, the wireless communication terminal inserts all MPDUs having a TID corresponding to the primary AC stored in the buffer into the A-MPDU, and within the maximum length that the A-MPDU can have at the corresponding transmission opportunity, the non-priority MPDU with head AC TID may be inserted.

In addition, the wireless communication terminal preferentially aggregates MPDUs having a TID corresponding to the primary AC and MPDUs having a non-primary AC TID having a relatively low counter value among the TIDs stored in the EDCA queue to generate an A-MPDU. can In addition, the wireless communication terminal may determine the number of TIDs included in the A-MPDU according to the maximum TID number information in the above-described embodiments.

FIG. 17( a ) shows the EDCA process of the first station STA1 in the embodiment of FIG. 17 . In the embodiment of FIG. 17 , AC used when the first station STA1 acquires a transmission opportunity is AC_VI. Therefore, the primary AC is AC_VI. In addition, the maximum number of TIDs that the MPDU included in the A-MPDU generated by the first station STA1 can have is four. In the embodiment of FIG. 17B , the first station STA1 generates an A-MPDU by aggregating an MPDU having a TID corresponding to the primary AC_VI and a management frame/control frame. Accordingly, the first station STA1 generates an A-MPDU by aggregating the MPDU and MMPDU having TID 2 corresponding to AC_VI. In the embodiment of FIG. 17( c ), the first station STA1 is an MPDU having a TID corresponding to the primary AC, an MPDU having a TID corresponding to an AC having a higher user priority than the primary AC, and a management frame/ A-MPDU is created by gathering control frames. Accordingly, the first station STA1 generates an A-MPDU by aggregating an MPDU having a TID 2 corresponding to AC_VI, an MMPDU, and an MPDU having a TID 1 corresponding to AC_VO. In addition, in the embodiment of FIG. 17( d ), the first station STA1 preferentially aggregates MPDUs having a TID corresponding to the primary AC and MPDUs having a TID having a relatively small counter value among TIDs stored in the EDCA queue. to generate an A-MPDU.

In the embodiment of FIG. 17 , among TIDs stored in the EDCA queue, counter values are smaller in the order of AC_VI, AC_BE, and AC_VO. Accordingly, the first station STA1 generates an A-MPDU by aggregating an MPDU having a TID 2 corresponding to AC_VI, an MMPDU, an MPDU having a TID 4 corresponding to AC_BE, and an MPDU having a TID 1 corresponding to AC_VO.

18 shows the format of a Multi-STA Block ACK frame according to an embodiment of the present invention.

The wireless communication terminal may transmit a Block ACK (BA) frame indicating whether a plurality of MPDUs have been received. In addition, the wireless communication terminal may receive a plurality of TID A-MPDUs (multi-STA multi-TID A-MPDU, single-STA multi-TID A-MPDU) or whether any one TID from each of the plurality of wireless communication terminals. A Multi-STA Block ACK (M-BA) frame that may indicate whether a multi-STA single TID (MPDU) is received may be transmitted. The M-BA frame may include a Per AID TID Info subfield indicating whether each AID and TID is received.

Specifically, the M-BA frame may include a BA control field. In this case, the BA control field may include information on the form and function of the BA. Also, the M-BA frame may include a BA Information field. The BA Information field may indicate an MPDU indicating whether the BA has received it. Also, the BA Information field may indicate whether data is received. Specifically, the BA Information field may include a bitmap indicating whether each MPDU or each sequence is received. In this case, the bitmap may be a Block ACK Bitmap field.

The Block ACK Bitmap field is a bitmap indicating whether data is received. A legacy wireless communication terminal may transmit one MSDU in up to 16 fragments. Accordingly, the legacy wireless communication terminal may indicate whether a fragment included in each of the 64 MSDUs is received by using the Block ACK Bitmap field having a length of 128 bytes. Specifically, the legacy wireless communication terminal may allocate each of 1024 bits of the Block ACK Bitmap field to each fragment included in the MSDU, and set a bit corresponding to the received fragment to 1. The legacy wireless communication terminal may indicate whether all fragments are received through the Block ACK Bitmap field. Therefore, the legacy wireless communication terminal may set the Fragment Number field of the Block ACK Starting Sequence Control field as a reserved field and use only the Sequence Number field.

As described above, the wireless communication terminal according to an embodiment of the present invention can fragment one MSDU into up to four fragments. In addition, the number of fragments that the wireless communication terminal can generate by fragmenting the MSDU varies according to the fragmentation level. Accordingly, the wireless communication terminal may change the display method of the Block ACK Bitmap field according to the fragmentation level. Specifically, when the fragmentation level applied to the data received by the wireless communication terminal is lower than level 3, the wireless communication terminal may set each bit of the Block ACK Bitmap field to indicate whether each MSDU is received. In addition, when the fragmentation level applied to the data received by the wireless communication terminal is level 3, the wireless communication terminal may set each bit of the Block ACK Bitmap field to indicate whether each fragment is received.

The BA Information field may include a Block ACK Starting Sequence Control subfield indicating data indicating whether the Block ACK Bitmap field is received. Specifically, the Block ACK Starting Sequence Control subfield may indicate the start number of data indicated by the Block ACK Bitmap field. The wireless communication terminal may indicate whether the bits of the Block ACK Bitmap field are divided in sequence units or fragment units through the Block ACK Starting Sequence Control subfield. Specifically, the wireless communication terminal may indicate that the bits of the Block ACK Bitmap field are divided in sequence units by setting the Least Significant Bit (LSB) of the Fragment Number subfield of the Block ACK Starting Sequence Control subfield to 0. In addition, the wireless communication terminal may set the LSB of the Fragment Number subfield of the Block ACK Starting Sequence Control subfield to 1 to indicate that the bits of the Block ACK Bitmap field are divided in fragment units. In addition, the wireless communication terminal may indicate the length of the Block ACK Bitmap field through the Block ACK Starting Sequence Control subfield. Specifically, the wireless communication terminal may indicate the length of the Block ACK Bitmap field by setting values of two bits (LSB+1, LSB+2) following the LSB of the Fragment Number subfield of the Block ACK Starting Sequence Control subfield. In this case, the number of BA Information fields included in the M-BA frame may vary depending on the number of wireless communication terminals that have transmitted data and the number of TIDs. Specifically, the M-BA frame may include the BA Information field repeatedly as many as the number of TIDs transmitted by a plurality of wireless communication terminals.

As described above, the wireless communication terminal may signal the fragmentation level supported by the wireless communication terminal in the link establishment procedure. In addition, the wireless communication terminal may negotiate a fragmentation level in the ADDBA procedure. At this time, when the receiver supporting the fragmentation level: level 3 does not receive any one MPDU included in the A-MPDU, the receiver determines at which fragmentation level the sender has transmitted the A-MPDU difficult. Therefore, a receiver supporting fragmentation level: level 3 can transmit an M-BA frame including a BA bitmap field divided in fragment units regardless of the configuration of the received A-MPDU.

19 and 20 show that the wireless communication terminal according to an embodiment of the present invention transmits an ACK for an A-MPDU including a fragment fragmented to fragmentation level 2.

When the fragmentation level is determined to be 2 or higher through fragmentation level negotiation or the like described above, the sender may transmit the A-MPDU to which the fragmentation of the fragment level 2 is applied. In this case, the receiver may transmit a BA frame including a bitmap indicating whether a sequence unit is received. In this case, the BA frame may be a Multi-STA BA frame. The bitmap indicating whether a sequence unit is received does not include information for identifying individual fragments, such as a fragment number. For example, in the embodiment of FIG. 19( a ), the transmitter transmits an A-MPDU including a plurality of fragments corresponding to sequence numbers 10 to 15 . The receiver transmits a Multi-STA BA frame indicating that a plurality of fragments corresponding to sequence numbers 10 to 15 have been received. In this case, the bitmap included in the Multi-STA BA frame indicates whether all fragments corresponding to a sequence number are received, but does not indicate which fragments are received among the fragments corresponding to the corresponding sequence number. In particular, the transmitter transmits only some fragments of the MSDU corresponding to sequence number 15, but the bitmap included in the Multi-STA BA frame does not indicate the fragment number of the corresponding fragment.

Accordingly, in order for the sender to process the bitmap indicating whether a sequence unit is received or not, the sender needs to store information that can identify the fragment or sequence transmitted by the sender. Therefore, depending on the function of the sender, the sender may not be able to process the bitmap indicating whether the sequence unit is received. For example, the sender may have to delete or retransmit the stored fragment depending on whether the receiver has received the individual fragment. In particular, the sender may have to retransmit a fragment having the same size as a previously transmitted fragment. To this end, the sender needs to track the size of the fragment transmitted by the sender. If the sender uses static fragmentation, the sender can track the size of the fragment without difficulty. This is because, in static fragmentation, all fragments of the same sequence have the same size except for the last fragment. However, when the sender uses dynamic fragmentation, the sender may have to store the sum of sizes of fragments transmitted for each sequence. This is because fragments of the same sequence may have different sizes in dynamic fragmentation. In addition, the wireless communication terminal cannot signal whether a bitmap indicating whether a sequence unit is received or not can be processed using information indicating a fragmentation level supported by the wireless communication terminal. This is because whether a bitmap indicating whether a sequence unit is received can be processed is independent of whether a fragment can be received.

Accordingly, the wireless communication terminal may receive the BA frame including the bitmap indicating whether the sequence unit is received from the sender and signal information indicating whether the bitmap indicating whether the sequence unit is received or not can be processed. For convenience of description, information indicating whether a bitmap indicating whether a sequence unit is received or not may be processed is referred to as a sequence unit ACK Capable indicator. The wireless communication terminal may signal the sequence unit ACK Capable indicator using a management frame in the link establishment procedure. In this case, the management frame includes a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, It may be at least one of an association response frame and a beacon frame.

In a specific embodiment, the wireless communication terminal may set the above-described All ACK capable indicator to 1 to signal that it can process a bitmap indicating whether a sequence unit is received or not. In this case, the HE Capability Information element may include an All ACK capable indicator as in the embodiment of FIG. 19( b ). As in the embodiment of FIG. 19( c ), when the All ACK capable indicator is 0, the receiver transmits a bitmap indicating whether a sequence unit is received even if the A-MPDU to which the fragment level 2 fragment is applied is received. It is not possible to transmit the BA frame including

The processing capability for the receiver to process the All ACK and the capability required for the receiver to process the bitmap indicating whether the receiver receives the sequence unit may be different. Specifically, when the receiver can process All ACKs, even though the receiver can process a bitmap indicating whether sequence units are received or not, when the receiver can process a bitmap indicating whether sequence units are received or not, the receiver receives All ACKs may not be able to process Accordingly, the wireless communication terminal may signal the sequence unit ACK Capable indicator separately from the All ACK capable indicator. In this case, the HE Capability Information element may include a sequence unit ACK Capable indicator (Fragmentation level 2 ACK capable) as in the embodiment of FIG. 20( a ).

In the embodiment of FIG. 20(b), the All ACK indicator transmitted by the sender is 0, and the sequence unit ACK Capable indicator is also 0. In this case, the receiver may transmit a BA frame including a bitmap indicating whether a fragment unit is received. In addition, in the embodiment of FIG. 20( c ), the All ACK indicator transmitted by the sender is 0 and the sequence unit ACK Capable indicator is also 1. In this case, the receiver may transmit a BA frame including a bitmap indicating whether a sequence unit is received. In addition, in the embodiment of FIG. 20(d), the All ACK indicator transmitted by the sender is 1, and the sequence unit ACK Capable indicator is also 1. In this case, the receiver may transmit an All ACK.

21 shows an operation of a wireless communication terminal according to an embodiment of the present invention.

The sender 2101 inserts a plurality of MPDUs into the A-MPDU (S2101). Specifically, the sender 2101 may generate a fragment by fragmenting an MSDU, an A-MSDU, or an MMPDU. In this case, the sender 2101 may use the dynamic fragmentation described above.

The sender 2101 transmits an A-MPDU including a plurality of MPDUs to the receiver 2103 (S2103). Specifically, the sender 2101 may transmit the A-MPDU including the fragment to the receiver 2103 . The sender 2101 may select any one fragmentation level from among a plurality of fragmentation levels, and may generate an A-MPDU including a fragment according to the selected fragmentation level. In this case, the sender 2101 may select a fragmentation level according to the embodiment of the fragmentation level negotiation procedure described above.

Also, the sender 2101 may transmit a plurality of TID A-MPDUs. In this case, the sender 2101 determines an MPDU having a TID corresponding to the primary AC based on the maximum length that the A-MPDU can have at the corresponding transmission opportunity, and a non-primary having a TID that is different from the TID corresponding to the primary AC. An A-MPDU may be generated by aggregating MPDUs having AC TIDs. Specifically, all MPDUs having a TID corresponding to the primary AC stored in the sender 2101 buffer are inserted into the A-MPDU, and the non-primary AC TID within the maximum length that the A-MPDU can have at the corresponding transmission opportunity is obtained. MPDU with In a specific embodiment, the sender 2101 may insert the MPDU having the non-primary AC TID into the A-MPDU based on the user priority corresponding to the TID. In this case, the user priority may be determined according to an access category (AC). The primary AC may indicate an AC of an MPDU that has acquired a transmission opportunity. For example, the sender 2101 generates an A-MPDU by aggregating an MPDU having a TID corresponding to the primary AC and an MPDU having a non-primary AC TID corresponding to an AC having a higher user priority than the primary AC. can do. Also, the sender 2101 may generate an A-MPDU by aggregating an MPDU having a TID corresponding to the primary AC, and at least one of a management frame and a control frame. Specifically, the sender 2101 may insert at least one of a management frame and a control frame into the A-MPDU, and insert an MPDU having a TID corresponding to the primary AC into the A-MPDU. Specifically, the sender 2101 may insert at least one of the management frame and the control frame into the A-MPDU regardless of the amount of the MPDU having the TID corresponding to the primary AC stored in the buffer. In another specific embodiment, the sender 2101 inserts an MPDU having a TID corresponding to the primary AC into the A-MPDU, and inserts at least one of a management frame and a control frame after the MPDU having a TID corresponding to the primary AC. It can be transmitted by being inserted into the A-MPDU with priority. In addition, the sender 2101 collects MPDUs having a TID corresponding to the primary AC, a management frame/control frame, and an MPDU having a non-primary AC TID corresponding to an AC having a higher user priority than the primary AC. A-MPDU can be generated. Specifically, the sender 2101 preferentially inserts a management frame or a control frame into the A-MPDU, and inserts an MPDU having a TID corresponding to a primary AC and an MPDU having a non-primary AC TID into the A-MPDU. can do. In this case, the sender 2101 inserts all MPDUs having a TID corresponding to the primary AC stored in the buffer into the A-MPDU as described above, and within the maximum length that the A-MPDU can have at the corresponding transmission opportunity, non- An MPDU with a primary AC TID may be inserted.

In addition, the sender 2101 generates an A-MPDU by preferentially aggregating MPDUs having a TID corresponding to the primary AC and MPDUs having a non-primary AC TID having a relatively low counter value among TIDs stored in the EDCA queue. can do. In addition, the sender 2101 may determine the number of TIDs included in the A-MPDU according to the maximum TID number information in the above-described embodiments. A specific operation of the sender 2101 may be the same as the embodiment described with reference to FIG. 17 .

The sender 2101 may manage fragment-related information for each combination of a receiver, a traffic identifier (TID), and a sequence number. The sender 2101 may create a new fragment based on information about the fragment. Specifically, the sender 2101 may determine a fragmentation start pointer of a new fragment based on information related to the fragment. Also, the sender 2101 may allocate a fragment number to a new fragment based on information related to the fragment. In this case, information about fragments may include information about a start pointer indicating a point where fragmentation starts and information about a fragment number. A specific operation of the sender 2101 may be the same as in the embodiments described with reference to FIG. 12 .

Also, the sender 2101 may insert a sequence number corresponding to the fragment into the fragment as in the embodiments described with reference to FIGS. 9 to 10 .

In another specific embodiment, the sender 2101 may store all fragments of the previously generated MSDU until the last fragment of the MSDU is generated. The sender 2101 may generate a new fragment based on all fragments of the previously generated corresponding MSDU. Specifically, the sender 2101 may determine a fragmentation start pointer of a new fragment based on all fragments of the previously generated corresponding MSDU. Also, the sender 2101 may allocate a fragment number to a new fragment based on all fragments of the previously generated corresponding MSDU. A specific operation of the sender 2101 may be the same as in the embodiments described with reference to FIG. 13 .

In another specific embodiment, the sender 2101 may generate all fragments of any one MSDU together. Specifically, the sender 2101 may generate all fragments for any one MSDU within the same transmission opportunity. A specific operation of the sender 2101 may be the same as in the embodiments described with reference to FIG. 14 .

In addition, the sender 2101 may signal information indicating whether the sender can process a specific ACK type. Specifically, the sender 2101 may transmit an All ACK capable indicator indicating whether the sender can process All ACKs.

In this case, the All ACK is an ACK indicating that the receiver has received an A-MPDU transmitted by any one transmitter or all MPDUs included in the multiple TID A-MPDU. Also, the transmitter 2101 may transmit capability information indicating whether a bitmap indicating whether data is received in a sequence unit can be processed. The capability information indicating whether a bitmap indicating whether data is received in a sequence unit can be processed may be the ACK capable indicator in a sequence unit as described above. The sender 2101 may transmit an ACK capable indicator. In addition, as described with reference to FIG. 19 , the transmitter 2101 may use the All ACK capable indicator to signal capability indicating whether a bitmap indicating whether data is received in a sequence unit can be processed.

The receiver 2103 receives an A-MPDU including a plurality of MPDUs from the transmitter 2101 . Specifically, the receiver 2103 may receive an A-MPDU including a fragment from the sender 2101 . The receiver 2103 transmits the BA frame to the transmitter 2101 according to the MPDU included in the received A-MPDU. In this case, the receiver 2103 may determine the format of the BA frame based on the order indicating whether a specific ACK type can be processed. Specifically, the receiver 2103 may determine whether to transmit a BA frame indicating All ACK to the receiver based on the All ACK capable indicator. Also, the receiver 2103 may determine whether to transmit a BA frame including a bitmap indicating whether a sequence unit is received or not based on the ACK Capable indicator to the receiver.

As described above, the present invention has been described using wireless LAN communication as an example, but the present invention is not limited thereto and may be equally applied to other communication systems such as cellular communication. Further, although the methods, apparatuses and systems of the present invention have been described with reference to specific embodiments, some or all of the components, operations, and/or operations of the present invention may be implemented using a computer system having a general-purpose hardware architecture.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by a person skilled in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

In the above, the embodiment has been mainly described, but this is only an example and does not limit the present invention, and those of ordinary skill in the art to which the present invention pertains are not exemplified above in a range that does not depart from the essential characteristics of the present embodiment. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Claims (6)

In a wireless communication terminal that communicates wirelessly,
transceiver; and
including a processor;
The processor inserts a MAC protocol data unit (MPDU) having a traffic identifier (TID) corresponding to a primary access category (AC) into an aggregate-MPDU (A-MPDU),
The primary AC based on the user priority corresponding to the TID corresponding to the primary AC, the maximum length that the A-MPDU can have at the corresponding transmission opportunity, and the maximum number of TIDs that the A-MPDU can have. inserting an MPDU having a non-primary AC TID, which is a TID different from the TID corresponding to , into the A-MPDU, and transmitting the A-MPDU to a receiver using the transceiver;
The maximum number of TIDs signaled from the receiver
wireless communication terminal. In claim 1,
the processor is
All MPDUs having a TID corresponding to the primary AC stored in the buffer are inserted into the A-MPDU, and the non-AC corresponding to an AC having a higher user priority than that of the primary AC within the maximum length. Inserting an MPDU having a primary AC TID into the A-MPDU
wireless communication terminal. In claim 1,
the processor is
Inserting a control frame into the A-MPDU
wireless communication terminal. In a method of operating a wireless communication terminal that communicates wirelessly
inserting an MPDU having a Traffic Identifier (TID) corresponding to the primary AC into an Aggregate-MAC Protocol Data Unit (A-MPDU);
The primary AC based on the user priority corresponding to the TID corresponding to the primary AC, the maximum length that the A-MPDU can have at the corresponding transmission opportunity, and the maximum number of TIDs that the A-MPDU can have. inserting an MPDU having a non-primary AC TID, which is a TID different from a TID corresponding to (Access Category), into the A-MPDU; and
transmitting the A-MPDU to a receiver;
The maximum number of TIDs signaled from the receiver
how it works. In claim 4,
The step of inserting the MPDU having the non-primary AC TID into the A-MPDU comprises:
inserting all MPDUs having a TID corresponding to the primary AC stored in a buffer into an A-MPDU, and within the maximum length, the non-functioning AC corresponding to an AC having a higher user priority than that of the primary AC within the maximum length. - Inserting an MPDU having a primary AC TID into the A-MPDU
how it works. In claim 4,
The method of operation is
Inserting a control frame into the A-MPDU further comprising
how it works.

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