WO2017217766A1

WO2017217766A1 - Wireless communication method using aggregate mpdu, and wireless communication terminal using same

Info

Publication number: WO2017217766A1
Application number: PCT/KR2017/006210
Authority: WO
Inventors: 안우진; 손주형; 곽진삼; 고건중
Original assignee: 주식회사 윌러스표준기술연구소
Priority date: 2016-06-14
Filing date: 2017-06-14
Publication date: 2017-12-21
Also published as: KR20220098042A; CN114884628B; KR20220034915A; KR102415048B1; KR102567626B1; CN114866197B; KR20220031144A; KR102371756B1; CN114884628A; CN114866197A; CN109314882A; KR102411787B1; CN109314882B; CN114900270A; KR20190008537A; CN114900270B

Abstract

Disclosed is a wireless communication terminal for performing communication wirelessly. The wireless communication terminal comprises a transmission/reception unit, and a processor. The processor transmits an A-MPDU for transmitting a plurality of MPDUs to a recipient by using the transmission/reception unit.

Description

Wireless communication method using the collective MPDU and wireless communication terminal using the same

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

Recently, with the expansion of mobile devices, wireless LAN technology that can provide a fast wireless Internet service to them is receiving a lot of attention. WLAN technology is a technology that enables wireless devices such as smart phones, smart pads, laptop computers, portable multimedia players, and embedded devices to wirelessly access the Internet at home, enterprise, or a specific service area based on wireless communication technology at a short range. to be.

Since IEEE (Institute of Electrical and Electronics Engineers) 802.11 supports the initial wireless LAN technology using the 2.4GHz frequency, various standards of technology are being put into practice or being developed. First, IEEE 802.11b supports communication speeds up to 11Mbps while using frequencies in the 2.4GHz band. IEEE 802.11a, which has been commercialized after IEEE 802.11b, reduces the influence of interference compared to the frequency of the congested 2.4 GHz band by using the frequency of the 5 GHz band instead of the 2.4 GHz band. Orthogonal Frequency Division Multiplexing, It uses OFDM technology to increase the communication speed up to 54Mbps. However, IEEE 802.11a has a shorter communication distance than IEEE 802.11b. And IEEE 802.11g, like IEEE 802.11b, uses a frequency of 2.4 GHz band to realize a communication speed of up to 54 Mbps and satisfies backward compatibility, which has received considerable attention. Is in the lead.

In addition, IEEE 802.11n is a technical standard established to overcome the limitation of communication speed, which has been pointed out as a weak point in WLAN. IEEE 802.11n aims to increase the speed and reliability of networks and to extend the operating range of wireless networks. More specifically, IEEE 802.11n supports High Throughput (HT) with data throughput of up to 540 Mbps and also uses multiple antennas at both the transmitter and receiver to minimize transmission errors and optimize data rates. It is based on Multiple Inputs and Multiple Outputs (MIMO) technology. In addition, the specification may use a coding scheme that transmits multiple duplicate copies to increase data reliability.

As the spread of wireless LANs is activated and applications are diversified, there is a need for a new wireless LAN system to support higher throughput (VHT) than the data throughput supported by IEEE 802.11n. It 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 backwards compatibility with existing 2.4GHz band products, early 11ac chipsets will also support operation in the 2.4GHz band. Theoretically, this specification allows multiple stations to have a minimum WLAN speed of 1 Gbps and a maximum single link speed of at least 500 Mbps. This is done by extending the concept of the wireless interface accepted by 802.11n, including wider radio frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to eight), multi-user MIMO, and higher density modulation (up to 256 QAM). In addition, IEEE 802.11ad is a method of transmitting data using a 60 GHz band instead of the existing 2.4 GHz / 5 GHz. IEEE 802.11ad is a transmission standard that uses beamforming technology to provide speeds of up to 7Gbps, and is suitable for streaming high bitrate video such as large amounts of data or uncompressed HD video. However, the 60 GHz frequency band is difficult to pass through obstacles, and thus can be used only between devices in a short space.

On the other hand, as the next generation wireless LAN standard after 802.11ac and 802.11ad, a discussion for providing a high-efficiency and high-performance wireless LAN communication technology in a high-density environment continues. That is, in a next generation WLAN environment, high frequency efficiency communication should be provided indoors / outdoors in the presence of a high density station and an access point (AP), and various technologies are required to implement this.

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.

One embodiment of the present invention is to provide a wireless communication terminal using the aggregate MPDU.

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

A transceiver; And a processor. The processor may transmit an aggregate-MAC protocol data unit (A-MPDU) including a fragment to a receiver by using the transceiver.

The processor may manage information about the fragment for each combination of a receiver, a traffic identifier (TID), and a sequence number, and generate 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.

The processor stores all fragments of the previously created MSDU until the last fragment of the MAC service data unit (MSDU) is generated, and based on all fragments of the previously created 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 the processor may process a bitmap indicating whether data in a sequence unit is received using the transceiver.

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

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 (ACD) 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 the corresponding TID, may be inserted into the A-MPDU, and the A-MPDU may be transmitted to the 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 the A-MPDU may have.

The processor may insert the MPDU with the non-primary AC TID into the A-MPDU based on the maximum length the A-MPDU may have in the corresponding transmission opportunity.

The processor inserts all MPDUs having a TID corresponding to the primary AC stored in a buffer into an A-MPDU and corresponds to an AC having a user priority higher than the user priority of the primary AC within the maximum length. The 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.

An operating method of a wireless communication terminal for wireless communication according to an embodiment of the present invention is a fragment by segmenting a MAC Protocol Data Unit (MPDU), an Aggregate-MAC Service Data Unit (A-MSDU) or a Management Protocol Data Unit (MMPDU). Creating a comment; And transmitting the A-MPDU including the fragment to a 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.

Storing all fragments of the previously created MSDU until the last fragment of the MSDU is created; And generating a new fragment based on all fragments of the previously generated corresponding MSDU.

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

The method may further include transmitting capability information indicating whether a bitmap indicating whether data received in a sequence unit may be processed using the bitmap.

The transmitting of 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, an operation method of a wireless communication terminal wirelessly communicating includes inserting an MPDU having a TID corresponding to primary AC into an Aggregate-MAC Protocol Data Unit (A-MPDU); Inserting, in the A-MPDU, an MPDU having a non-primary AC TID which is a different TID from a TID corresponding to the primary AC based on a user priority corresponding to a 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 the MPDU having the non-primary AC TID based on the maximum length that the A-MPDU may have at a corresponding transmission opportunity. Inserting into the MPDU.

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

1 illustrates a WLAN system according to an embodiment of the present invention.

2 shows a WLAN system according to another embodiment of the present invention.

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

4 is a block diagram illustrating a configuration of an access point according to an embodiment of the present invention.

5 schematically shows a process of establishing a link with an access point by a station according to an embodiment of the present invention.

6 illustrates a method of transmitting a block ACK (BA) frame for an Aggregate-MAC Protocol Data Unit (A-MPDU) by a wireless communication terminal according to an exemplary embodiment of the present invention.

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

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.

FIG. 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.

FIG. 11 is a diagram illustrating assigning a fragment number to a fragment in a wireless communication terminal dynamic fragmentation operation according to an embodiment of the present invention.

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

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

FIG. 14 is a diagram illustrating assigning a fragment number to a fragment in a wireless communication terminal dynamic fragmentation operation according to another embodiment of the present invention.

FIG. 15 illustrates a method of transmitting, by a wireless communication terminal, 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 illustrates a method for configuring a plurality of TID A-MPDUs by a wireless communication terminal according to an embodiment of the present invention.

19 and 20 illustrate that a 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 illustrates an operation of a wireless communication terminal according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

This application is a priority based on Korean Patent Application Nos. 10-2016-0074090 (June 14, 2016), 10-2016-0093811 (July 23, 2016) and 10-2016-0104407 (2016.08.17) It is claimed that the embodiments and descriptions set forth in the above-mentioned applications, which are the basis of priority, are included in the detailed description of the present application.

1 illustrates a WLAN system according to an embodiment of the present invention. The WLAN system includes one or more Basic Service Sets (BSSs), which represent a set of devices that can successfully synchronize and communicate with each other. In general, the BSS may be classified into an infrastructure BSS (Independent BSS) and an Independent BSS (IBSS), and FIG. 1 illustrates an infrastructure BSS.

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

A station (STA) is any device that includes a medium access control (MAC) compliant with the IEEE 802.11 standard and a physical layer interface to a wireless medium. This includes both access points (APs) as well as non-AP stations. In addition, in the present specification, the term 'terminal' may be used as a concept including both a station and an WLAN communication device such as an AP. The station for wireless communication may include 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 processing for controlling the station. The transceiver is functionally connected to the processor and transmits and receives a frame through a wireless network for a station.

An access point (AP) is an entity that provides access to a distribution system (DS) via a wireless medium for an associated station to the AP. In the infrastructure BSS, communication between non-AP stations is performed via an AP. However, when a direct link is established, direct communication between non-AP stations is possible. Meanwhile, in the present invention, the AP is used as a concept including a personal BSS coordination point (PCP), and is broadly used as a centralized controller, a base station (BS), a node-B, a base transceiver system (BTS), or a site. It can include all the concepts such as a controller.

The plurality of infrastructure BSSs may be interconnected through a distribution system (DS). At this time, the plurality of BSSs connected through the distribution system is referred to as an extended service set (ESS).

2 illustrates an independent BSS, which is a wireless LAN system according to another embodiment of the present invention. In the embodiment of FIG. 2, the same or corresponding parts as those of the embodiment of FIG. 1 will be omitted.

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. Independent BSSs do not allow access to the distribution system and form a self-contained network. In the independent BSS, the respective stations STA6 and STA7 may be directly connected to each other.

3 is a block diagram showing the configuration of a 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 140, a display unit 150, and a memory 160. .

First, the transceiver 120 transmits and receives a radio signal such as a WLAN physical layer frame, it may be built in the station 100 or may be provided externally. 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 a transceiver module 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 more and a transmission / reception module using a frequency band of 6 GHz or less. Each transmit / receive 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 transmit / receive module. The transceiver 120 may operate only one transceiver module at a time or simultaneously operate multiple transceiver modules 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 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 a 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 according thereto. Such a control program may include an access program necessary for the station 100 to perform an access with an AP or an external station.

The processor 110 of the present invention may execute various instructions or programs and process data in the station 100. In addition, the processor 110 may control each unit of the station 100 described above, and may control data transmission and reception between the units. According to an embodiment of the present disclosure, the processor 110 may execute a program for accessing an AP stored in the memory 160 and receive a communication setup message transmitted by the AP. In addition, the processor 110 may read information on the priority condition of the station 100 included in the communication configuration message, and request a connection 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 part of the station 100 may be referred to, for example, a control unit for individually controlling the transceiver 120 and the like. You can also point it. That is, the processor 110 may be a modulation unit or a demodulator (modulator and / or demodulator) for modulating the radio signal transmitted and received from the transceiver unit 120. The processor 110 controls various operations of radio signal transmission and reception of the station 100 according to an embodiment of the present invention. Specific embodiments thereof will be described later.

The station 100 illustrated in FIG. 3 is a block diagram according to an embodiment of the present invention, in which blocks marked separately represent logical elements of devices. Therefore, the elements of the above-described device may be mounted in one chip or in 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 the 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 illustrating a configuration of an AP 200 according to an exemplary embodiment.

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, overlapping descriptions of parts identical or corresponding to those of the station 100 of FIG. 3 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 the embodiment of the present invention may be provided with two or more transmit / receive modules of 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 more and a transmission / reception module using a frequency band of 6 GHz or less. Each transmit / receive module may perform wireless communication with a station according to a wireless LAN standard of a frequency band supported by the corresponding transmit / receive module. The transceiver 220 may operate only one transceiver module at a time or simultaneously operate multiple transceiver modules 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 according thereto. Such a control program may include an access program for managing a connection of a station. In addition, the processor 210 may control each unit of the AP 200 and may control data transmission and reception between the units. According to an embodiment of the present disclosure, the processor 210 may execute a program for accessing 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 a connection request of a station. According to an embodiment, the processor 210 may be a modulator or demodulator for modulating a radio signal transmitted and 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. Specific embodiments 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 obtains access information of a BSS operated by the AP 200. As a method for scanning, a passive scanning method for obtaining information by using only a beacon message S101 periodically transmitted by the AP 200, and a STA 100 requests a probe to the AP. There is an active scanning method of transmitting a probe request (S103) and receiving a probe response from the AP (S105) to obtain access information.

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

Meanwhile, the 802.1X based authentication step S111 and the IP address obtaining 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 be physically coupled to the AP 200 or may exist as a separate server.

According to a specific embodiment, the AP 200 may be a wireless communication terminal for allocating communication mediator resources and performing scheduling in an independent network that is not connected to an external distribution service such as an ad-hoc network. In addition, the AP 200 may be at least one of a base station, an eNB, and a transmission point (TP). In addition, 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 that is a data processing unit for each layer. In more detail, the wireless communication terminal may generate a MAC Protocol Data Unit (MPDU) in a Medium Access Control (MAC) layer and 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. A detailed operation of the sender and the receiver will be described with reference to FIGS. 6 through x.

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

At the MAC layer, the wireless communication terminal receives a MAC Service Data Unit (MSDU) from a Logical Link Control (LLC) layer. At this time, 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. In detail, 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 obtain a transmission opportunity through a competition procedure. In more detail, the wireless communication terminal may start a contention procedure for channel access when the wireless medium is idle. In addition, the wireless communication terminal may acquire a channel access right 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. In more detail, the wireless communication terminal may transmit 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. In more detail, the wireless communication terminal allocates a sequence number for each MSDU. The wireless communication terminal also assigns a new sequence number to the MSDU every time a new MSDU is transmitted. Specifically, each time the wireless communication terminal transmits a new MSDU, the wireless communication terminal may assign the MSDU a sequence number increased by one 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). In more detail, the wireless communication terminal can determine the sequence number of the MAC frame using a sequence number space (SNS). The wireless communication terminal may generate an MPDU in the MAC layer and determine a sequence number to be allocated to the MSDU using SNS. Accordingly, the wireless communication terminal can 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 MPDU. Therefore, the wireless communication terminal stores the MPDU until receiving the ACK for the MPDU. Specifically, the wireless communication terminal caches the MPDU until receiving an 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 the information indicating that the receiver has not received the MPDU, the wireless communication terminal may retransmit the MPDU. In this case, the information indicating that the ACK and the receiver did not receive the MPDU may be received through at least one of an ACK frame, a block ACK frame, and a multi-STA BA frame. The wireless communication terminal also stores the MSDU in a buffer. The wireless communication terminal deletes from the buffer the MSDU successfully transmitted to the receiver.

In the embodiment of FIG. 5, the first station STA1 transmits an MSDU having a TID of 2 to a receiver having a RA of 3. In this case, the sequence number value stored in the SNS where the RA of the first station STA1 is 3 and the TID is 2 is 30. Accordingly, the first station STA1 allocates 31, 32, and 33 as sequence numbers to each of 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 MSDUs corresponding to sequence

numbers

31 and 33 from the cache.

If the size of the MSDU is large, the wireless communication terminal may fragment and transmit the MSDU. If 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 Ag-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 more detail, 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 generated plurality of fragments to the plurality of MPDUs. In addition, the wireless communication terminal receiving the plurality of fragments may defragment the plurality of fragments to obtain at least one of one MSDU, one A-MSDU, and one MMPDU. . In this case, the MPDU may be an S-MPDU or an A-MPDU. The wireless communication terminal may generate the remaining fragments except the last fragment in a fixed size. In addition, the wireless communication terminal may generate a fragment with a fixed size. Fragments having a fixed size of fragments other than the last fragment are called static fragmentations. Fragmentation in which the size of the fragment is not fixed is referred to as dynamic fragmentation. Static fragmentation is described in detail with reference to FIG. 7, and static fragmentation is described in detail with reference to FIG. 8.

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

The radio communication terminals all assign the same sequence number to fragments that fragment the same MSDU. In addition, the radio communication terminal assigns a fragment number (FN) to the fragment. In more detail, the wireless communication terminal may allocate a new fragment number every time a fragment is generated by fragmenting the same MSDU. The wireless communication terminal may allocate a fragment number for each combination of the same RA, TID, and sequence number. According to a specific embodiment, the wireless communication terminal may allocate a fragmentation number that increases by 1 for each fragment generated from the same MSDU. In this case, the wireless communication terminal may assign a fragment number from 0 to the fragment. In addition, the wireless communication terminal may generate a fragment when starting the transmission sequence of the MSDU. The wireless communication terminal transmits the fragment using the MPDU, and then 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 the fragments and efficiently manage the fragments.

The wireless communication terminal can continuously transmit each of a plurality of fragments generated from the same MSDU as one MPDU. Such a transmission method may be referred to as a fragment burst. In fragment burst transmission, when the wireless communication terminal receives the ACK for the previously transmitted MPDU, the next MPDU may be transmitted within a predetermined time from when the ACK is received 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 all fragments generated from the same MSDU. In fragment burst transmission, the wireless communication terminal may generate one fragment at a time. In more detail, a fragment may be generated when an ACK for an MPDU previously transmitted is received. In such an embodiment, the wireless communication terminal transmits only an MPDU including one fragment at a time and cannot transmit an A-MPDU transmitting a plurality of MPDUs. In the fragment burst transmission, if the wireless communication terminal does not receive an ACK for the previously transmitted MPDU, the wireless communication terminal returns a transmission opportunity. In this case, the wireless communication terminal may retransmit an opportunity to retransmit through a contention procedure and retransmit an MPDU including a previously transmitted fragment. In more detail, the wireless communication terminal may retransmit the MPDU including the stored fragment. In this case, the stored fragment may represent a cached fragment as described above.

In fragment burst transmission, the wireless communication terminal generates a new fragment when it receives the ACK for the previously transmitted MPDU as described above. At this time, the wireless communication terminal allocates a fragment number to a new fragment based on the stored fragment. In more detail, the wireless communication terminal may allocate the number greater than 1 to the fragment number of the stored fragment as the fragment number of the new fragment. In this case, when generating the first fragment from the MSDU, the wireless communication terminal may allocate 0 as the fragment number of the corresponding fragment. In addition, the wireless communication terminal may determine a starting point of the MSDU to generate the fragment based on the size of the fragment. The wireless communication terminal generates a fragment and deletes the stored fragment. In such an embodiment, the wireless communication terminal may generate a new fragment and assign a fragment number using only the stored fragment. Therefore, the wireless communication terminal may not use the tracking space for tracking the fragment number assignment and the fragment start point.

In the embodiment of FIG. 7, the first station STA1 fragments and transmits one MSDU into four fragments. Since the first station STA1 has a sequence number of a previously transmitted MSDU of 30, the first station STA1 allocates a sequence number of 31 and a fragment number of 0 of the first fragment 31.0. 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. In addition, since the fragmentation 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. In addition, since the fragmentation number of the cached fragment is 1, the first station STA1 allocates 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 competition procedure. The first station sends back an MPDU containing the cached third fragment 31.2. The first station STA1 receives an 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. In addition, since the fragmentation number of the cached fragment is 2, the first station STA1 allocates the fragment number of the third fragment 31.3 to 3. The first station STA1 transmits an MPDU including the fourth fragment 31.3, and the first station STA1 receives an ACK frame for the MPDU including the fourth fragment 31.3.

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

As described above, the wireless communication terminal may generate a fragment with a fixed size. In addition, the wireless communication terminal may transmit the MPDU including the fragment with the other MPDU. In more detail, the wireless communication terminal may transmit an A-MPDU including an MPDU different from an MPDU including a fragment.

In addition, when dynamic fragmentation is used, the sender generates a fragment according to the fragmentation level and transmits an MPDU including the fragment. In this case, the sender may determine the fragmentation level based on the capability of the receiver. At this time, 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 for the MSDU received. In addition, level 1 may indicate that the wireless communication terminal may receive an MPDU including one fragment. In this case, the MPDU may be a single MPDU that is not aggregated with another MPDU 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. In detail, 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 per MSDU. In detail, level 3 may indicate that the wireless communication terminal may receive an A-MPDU including 4 or less fragments per MSDU. The sender and receiver may signal information about the fragmentation level in the link setup procedure. In addition, the sender and the receiver may negotiate information on the fragmentation level in the ADDBA procedure. This will be described in detail with reference to FIGS. 15 to 20.

In the embodiment of Figure 8, the receiver supports fragmentation level 3. In the embodiment of FIG. 7A, the sender fragments the MSDU to fragmentation level 2. Therefore, the sender sends an A-MPDU containing fragments of different MSDUs to the receiver one by one. In this case, 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 of the MSDU corresponding to sequence number 8 Fragment (8.0), the first fragment (9.0) of the MSDU corresponding to sequence number 9, and the first fragment (10.0) of the MSDU corresponding to sequence number 10. In the embodiment of FIG. 7B, the sender fragments the MSDU to fragmentation level 3. Therefore, the sender sends an A-MPDU containing 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), the sequence of the MSDU corresponding to the sequence number 7 The first fragment (8.0) and the second fragment (8.1) of the MSDU corresponding to the number 8 are included.

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

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

The first station STA1 transmits an A-MPDU including an MSDU different from the MSDU corresponding to the sequence number 8, and a second fragment 8.1 of the MSDU corresponding to the sequence number 8. At this time, since the first station STA1 cannot transmit all the fragments of the MSDU corresponding to the sequence number 8, the first station STA1 maintains the previous sequence number managed by the SNS as 7. Accordingly, the first station STA1 allocates 8 as a sequence number to an MSDU different from the MSDU corresponding to the sequence number 8. The receiver determines whether duplicate MSDUs are received based on the sequence number and the fragment number. Accordingly, in the case of the embodiment 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 MSDU to the sender and may not transmit the MSDU to a higher layer.

When the wireless communication terminal generates the first MPDU containing the fragment of the MSDU, the wireless communication terminal may increase 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 associated with the SNS by one.

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

The first station STA1 transmits an A-MPDU including an MSDU 9.0 corresponding to the sequence number 9 and a second fragment 8.1 of the MSDU corresponding to the 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 assign 9 to the sequence number to the new MSDU even though all fragments of the MSDU corresponding to the sequence number 8 have not been transmitted.

If the wireless communication terminal uses static fragmentation, the wireless communication terminal may determine the fragmentation start pointer for the MSDU based on the fragment transmitted last. At this time, the fragmentation start pointer indicates a point at which fragmentation for the fragment begins in the MSDU. This is because the fragment size is fixed except for the last fragment. In particular, when the fragmentation number is increased from 0 to 1, the wireless communication terminal may determine the start pointer of the fragmentation for the MSDU based on the fragment number of the last transmitted fragment. However, if the wireless communication terminal uses dynamic fragmentation, the wireless communication terminal may not be able to determine the start pointer of the fragment for the MSDU based on the fragment number of the last transmitted fragment.

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

When the first station STA1 transmits the remaining fragments of the MSDU with TID 1 and the sequence number 8 or the remaining fragments of the MSDU with TID 2 and the sequence number 32, the first station STA1 Does not know the start pointer of each MSDU. In addition, the first station SAT1 may not know which fragment number to assign to the fragment to transmit.

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

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

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

The first station STA1 maintains a first FNS and a second FNS. In this case, the first FNS stores information for fragment transmission having a TID of 1 and a sequence number of 8 for the first receiver. In more detail, the first FNS includes a fragment sum of fragments having a TID of 1 and a sequence number of 8 transmitted to the first receiver, and a fragment having a sequence number of 8 and a TID of 1 last transmitted to the first receiver. Stores 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 has a fragment sum of fragments having a TID of 2 and a sequence number of 32 transmitted to the second receiver, and a fragment having a sequence number of 32 and a TID of 2 last transmitted to the second receiver. Stores the fragment number (0). Accordingly, the first station STA1 determines a fragmentation start pointer of the fragment having a TID of 1 and a sequence number of 8 based on the first FNS. In addition, the first station STA1 assigns 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 the fragment having a TID of 2 and a sequence number of 32 for the second receiver based on the second FNS. In addition, 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.

In another specific embodiment, the wireless communication terminal may store all fragments of the corresponding MSDU previously generated until the last fragment of the MSDU is generated. In more detail, the wireless communication terminal may cache all fragments of the corresponding MSDU previously generated until the last fragment of the MSDU is generated. The wireless communication terminal may generate a new fragment based on the stored fragment. In more detail, 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 assign a fragment number to a new fragment based on the stored fragment. In more detail, the wireless communication terminal may store an MPDU including all fragments of the corresponding MSDU previously generated until the last fragment of the MSDU is generated. To this end, the wireless communication terminal can transmit a BAR frame requesting a BA frame only to the MSDU transmitting all fragments to the receiver. This is because the wireless communication terminal can store the MPDU until receiving the ACK from the receiver.

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

At this time, since the first station STA1 has not transmitted all fragments of the MSDU with TID 1 and the sequence number 8 and all fragments of the MSDU with TID 2 and the sequence number 32, TID is 1 Cache fragments with sequence number 8 and fragments with TID 2 and sequence number 32. Accordingly, the first station STA1 determines a fragmentation start pointer of a fragment having a TID of 1 and a sequence number of 8 based on the cached fragment. In addition, 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 receiver based on the cached fragment. In addition, 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 such an embodiment, the wireless communication terminal can efficiently manage information about a fragment without storing additional information.

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

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

At this time, the first station STA1 generates three fragments of MSDUs having a TID of 1 and a sequence number of 8 at one transmission opportunity. However, as described above, the first station STA1 transmits only one fragment 8.0 and transmits the other two fragments 8.1 and 8.2 to the next transmission opportunity. In addition, the first station STA1 generates three fragments of MSDUs 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 other two fragments 331 and 32.2 to the next transmission opportunity. According to this embodiment, the wireless communication terminal can efficiently manage information about a fragment without storing extra information or caching the fragment.

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 A-MPDUs 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 each of a plurality of different TIDs may be referred to as a multi-TID A-MPDU or an A-MPDU having a plurality of TIDs. with Multiple TIDs). The wireless communication terminal can increase the A-MPDU transmission efficiency through this. In more detail, the wireless communication terminal may transmit an A-MPDU having a plurality of TIDs by using a physical layer protocol data unit (HE PPDU). In this case, the HE PPDU may be a HE MU (Multi User) PPDU. In addition, 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 a parameter related to A-MPDU transmission having a plurality of TIDs in a link establishment procedure. In more detail, the wireless communication terminal may transmit maximum TID number information indicating the maximum number of TIDs that the wireless communication terminal can simultaneously receive in a link establishment procedure. In this case, the wireless communication terminal may transmit the maximum number of TID information using the HE capability information element which is information indicating the capability of the terminal. This is because, as the number of TIDs of A-MPDUs having a plurality of TIDs increases, higher processing capability of the wireless communication terminal receiving the A-MPDUs may be required. The maximum TID number information may be a maximum number of TID field of the HE capability information element. The maximum number of TIDs that an 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 the wireless communication terminal other than the AP. It can represent the number. In addition, the maximum number of TIDs transmitted by the 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 corresponding AP may have. In the link establishment procedure, the wireless communication terminal can transmit the maximum number of TID information using a management frame. In this case, the management frame may include 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 maximum TID number information using a beacon frame, the maximum TID number information may indicate the number of TIDs that the AP can simultaneously receive. In more detail, when the AP transmits the maximum number of TIDs using a beacon frame, the maximum number of TIDs is not the maximum number of TIDs that an MPDU included in an A-MPDU transmitted by any one of the wireless communication terminals to the AP. In UL transmission, this may indicate the maximum number of TIDs allowed for transmission. This is because the AP transmits a beacon frame to all wireless communication terminals of the BSS operated by the AP. In another specific embodiment, the maximum TID number information of the 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 a 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 all MPDUs included in an A-MPDU or a plurality of TID A-MPDUs transmitted by one transmitter. When the All ACK is transmitted, the sender cannot know the information about the fragment transmitted from the All ACK. In order to process the All ACK, the sender must store information about fragments sent by the sender. This is because the sender may not be able to store information about the fragments transmitted by the sender. In more detail, the wireless communication terminal can transmit an All ACK capable indicator indicating whether the 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 that transmits data is referred to as an originator, and a wireless communication terminal that receives data is referred to as a recipient.

In more detail, 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 generated plurality of fragments to the plurality of MPDUs. In addition, the wireless communication terminal receiving the plurality of fragments may defragment the plurality of fragments to obtain at least one of one MSDU, one A-MSDU, and one MMPDU. . 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 fragments until all fragments of the MSDU corresponding to the same sequence number are received. Thus, when the receiver supports the capability required for receiving the fragment, the sender can send the fragment to the receiver. After all, the sender needs to know the fragmentation level that the receiver supports. The wireless communication terminal can signal for the fragmentation level. In more detail, the wireless communication terminal transmits information about the fragmentation level of the fragment that the wireless communication terminal can receive in a link establishment procedure with the AP, and the fragmentation of the fragment that the AP can receive. Information about the level can be received. In more detail, the wireless communication terminal can transmit information on 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 may include a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, and an association response. At least one of the response frames 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. The specific format of the HE capability information element may be the same as that of the embodiment of FIG. 15.

In addition, the wireless communication terminal may set the BA parameter in the Add Block ACK (ADDBA) procedure. At this time, the BA parameter is a parameter used for BA frame transmission and BA frame reception. The wireless communication terminal may request 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. At this time, the Block Ack Parameter Set element includes information about the BA parameter. In addition, the wireless communication terminal may set a BA parameter for each TID. In more detail, the wireless communication terminal may negotiate BA parameter setting for each TID. According to a specific embodiment of the present invention, the wireless communication terminal may designate a TID to be subjected to BA parameter setting negotiation by using a TID field included in a Block Ack Parameter Set element. The sender may request BA parameter setting by transmitting an ADDBA request frame. The receiver may receive the ADDBA request frame and transmit the ADDBA response frame to the ADDBA request frame to confirm the BA parameter setting. When the sender receives the ADDBA response frame and sends 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 receiving a BA frame after receiving data in the ADDBA procedure. In more detail, the wireless communication terminal may transmit buffer size information using a Block Ack Parameter Set element in the ADDBA procedure. The wireless communication terminal may set the length of the BA bitmap based on a range of values that the buffer size information may have. Specifically, when the range of values that the buffer size information can have is 1 to 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 about the length of the BA bitmap, the wireless communication terminal may set the length of the BA bitmap to X bits. The specific format of the Block Ack Parameter Set element may be the same as 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 BA parameter set in the capability of the AP and the ADDBA procedure. The 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 score board indicates information in which the AP records the reception state of each MPDU. Accordingly, the AP may indicate the maximum number of TIDs that an A-MPDU each of the wireless communication terminals may have using the trigger frame. In more detail, the AP may indicate a maximum TID to be transmitted by each wireless communication terminal using a user info field of a 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. In detail, the wireless communication terminal receiving the trigger frame may set the number of TIDs of the MPDU 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 of the MPDU included in the A-MPDU to be transmitted so as not to exceed 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 a single user (SU) Uplink (UL) transmission, the wireless communication terminal may be restricted from transmitting the A-MPDU having a plurality of TIDs. The wireless communication terminal may use a relatively wide transmission range in a narrow frequency band using the HE MU PPDU in the 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, a fairness problem may occur in terms of competition with other wireless communication terminals. Therefore, when the wireless communication terminal uses the HE MU PPDU in the SU UL transmission, the wireless communication terminal may be limited to transmit the A-MPDU having a plurality of TIDs.

When the wireless communication terminal transmits the HE trigger-based PPDU or transmits the HE MU PPDU in the 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 a predetermined condition even in the SU transmission. In more detail, the wireless communication terminal may transmit a plurality of TID A-MPDUs using the HE MU PPDU. In addition, the wireless communication terminal may set the number of TIDs of the plurality of TID A-MPDUs based on the maximum number of TIDs described above. 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. In the uplink transmission, the wireless communication terminal may obtain maximum TID number information from the combined response frame or the authentication response frame. In addition, in downlink transmission, the wireless communication terminal may obtain the maximum TID number information from the association request frame or the authentication request frame.

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

In the embodiment of FIG. 16B, 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 obtains the HE Capability information element from the association request (Assoc. Req.) Frame. In addition, the AP obtains a maximum TID number 4 from the Max number of TID field of the HE Capability information element. Therefore, the AP transmits a plurality of TID A-MPDUs having four or less TIDs to the wireless communication terminal other than the AP.

The wireless communication terminal aggregates MPDUs stored in an EDCA queue to generate an A-MPDU. At this time, the wireless communication terminal is based on the maximum length that the A-MPDU can have a transmission opportunity MPDU having a TID corresponding to the primary AC, non-primary (TID) that is different from the TID corresponding to the primary AC ( Non-Primary) A-MPDU may be generated by collecting MPDUs having an AC TID. Specifically, the wireless communication terminal inserts all MPDUs having the TID corresponding to the primary AC stored in the buffer into the A-MPDU, and transmits the non-primary AC TID within the maximum length that the A-MPDU can have in the transmission opportunity. It is possible to insert the MPDU having. According to a specific embodiment, the wireless communication terminal may insert an MPDU having a non-primary AC TID into the A-MPDU based on a user priority corresponding to the TID. In addition, the primary AC may represent the AC of the MPDU having obtained the transmission opportunity. For example, the wireless communication terminal may generate an A-MPDU by collecting 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 user priority greater than the primary AC. have.

In addition, the wireless communication terminal may generate an A-MPDU by collecting at least one of an MPDU having a TID corresponding to the primary AC, a management frame, and a control frame. In more detail, the wireless communication terminal 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. In another specific embodiment, the wireless communication terminal inserts an MPDU having a TID corresponding to a primary AC into an A-MPDU, and inserts at least one of a management frame and a control frame into an MPDU having a TID corresponding to the primary AC. It can be inserted into the A-MPDU and transmitted in order. In addition, the wireless communication terminal aggregates the MPDU having a TID corresponding to the primary AC, the management frame / control frame, and the MPDU having the non-primary AC TID corresponding to the AC having a user priority greater than the primary AC. MPDUs can be created. Specifically, the wireless communication terminal preferentially inserts a management frame or control frame into the A-MPDU, and inserts an MPDU having a TID corresponding to primary AC and an MPDU having a non-primary AC TID into the A-MPDU. Can be. In this case, 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 non-fried within the maximum length that the A-MPDU may have in the transmission opportunity. The MPDU with the head AC TID may be inserted.

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

FIG. 17A illustrates an EDCA process of the first station STA1 in the embodiment of FIG. 17. In the embodiment of FIG. 17, the AC used when the first station STA1 acquires a transmission opportunity is AC_VI. Thus primary AC is AC_VI. In addition, the maximum number of TIDs that an MPDU included in an A-MPDU generated by the first station STA1 may have is four. In the embodiment of FIG. 17B, the first station STA1 generates an A-MPDU by collecting 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 collecting MPDUs and MMPDUs having a TID 2 corresponding to AC_VI. In the embodiment of FIG. 17C, the first station STA1 may be an MPDU having a TID corresponding to a 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 generated by aggregating control frames. Accordingly, the first station STA1 generates an A-MPDU by collecting MPDUs, MMPDUs having TID 2 corresponding to AC_VI, and MPDUs having 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 primary AC and MPDUs having a relatively small TID among TIDs stored in an EDCA queue. To create an A-MPDU.

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

18 shows a 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 corresponds to any one of a plurality of TID A-MPDUs (multi-STA multi-TID A-MPDU, single-STA multi-TID A-MPDU) or a plurality of TIDs 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 to receive by AID and TID.

In more detail, the M-BA frame may include a BA control field. In this case, the BA control field may include information about the type and function of the BA. In addition, the M-BA frame may include a BA Information field. The BA Information field may indicate an MPDU indicating whether the BA has received. In addition, the BA Information field may indicate whether data is received. In more detail, 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. The legacy wireless communication terminal can transmit one MSDU in up to 16 fragments. Accordingly, the legacy wireless communication terminal may indicate whether a fragment included in each of 64 MSDUs is received using a Block ACK Bitmap field having a length of 128 bytes. In more detail, 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. Accordingly, 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 the embodiment of the present invention may 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. Therefore, the wireless communication terminal can change the display method of the Block ACK Bitmap field according to the fragmentation level. In more detail, 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 that each bit of the Block ACK Bitmap field indicates whether the 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 be set to each of the bits of the Block ACK Bitmap field indicating whether or not to receive each fragment.

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

As described above, the wireless communication terminal may signal a fragmentation level supported by the wireless communication terminal in a link establishment procedure. In addition, the wireless communication terminal may negotiate the fragmentation level in the ADDBA procedure. In this case, when the receiver supporting the fragmentation level: level 3 does not receive any MPDU included in the A-MPDU, the receiver determines to which fragmentation level the sender transmits the A-MPDU. It is difficult. Therefore, a receiver supporting fragmentation level: level 3 may transmit an M-BA frame including a BA bitmap field divided by fragments regardless of the configuration of the received A-MPDU.

When the fragmentation level is determined to be 2 or more through the fragmentation level negotiation described above, the sender may transmit the A-MPDU to which the fragmentation of 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 an individual fragment, such as a fragment number. For example, in the embodiment of FIG. 19A, the sender 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 the fragment corresponding to the sequence number has been received, but does not indicate which fragment among the fragment corresponding to the sequence number has been received. In particular, the transmitter transmits only some fragments of the MSDU corresponding to the sequence number 15, but the bitmap included in the Multi-STA BA frame does not indicate the fragment number of the fragment.

Therefore, in order for the sender to process a bitmap indicating whether the sender receives a sequence unit, the sender needs to store information for identifying a fragment or sequence transmitted by the sender. Therefore, depending on the function of the sender, the sender may not be able to process a bitmap indicating whether or not a sequence unit is received. For example, the sender may need to delete or resend stored fragments depending on whether the recipient has received individual fragments. In particular, the sender may need to resend fragments of the same size as the previously transmitted fragments. For this purpose, the sender needs to track the size of the fragment transmitted by the sender. If the sender uses static fragmentation, the sender can easily track the size of the fragment. This is because fragments of the same sequence in the static fragmentation have the same size except for the last fragment. However, if the sender uses dynamic fragmentation, the sender may need to store the sum of the sizes of the fragments transmitted per sequence. This is because even fragments of the same sequence in dynamic fragmentation may have different sizes. In addition, the wireless communication terminal cannot signal whether it is possible to process a bitmap indicating whether or not reception of a sequence unit is performed by using information indicating a fragmentation level supported by the wireless communication terminal. This is because it is irrelevant whether or not a bitmap indicating whether or not a sequence unit can be processed can be processed.

Accordingly, the wireless communication terminal may signal information indicating whether it is possible to process a bitmap indicating whether or not receiving a sequence unit by receiving a BA frame including a bitmap indicating whether or not receiving a sequence unit from the transmitter. For convenience of description, information indicating whether a bitmap indicating whether a sequence unit is received can 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 a link establishment procedure. In this case, the management frame may include 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.

According to a specific embodiment, the wireless communication terminal may signal that it is possible to process the bitmap indicating whether the reception of the sequence unit by setting the All ACK capable indicator described above to 1. In this case, the HE Capability Information element may include an All ACK capable indicator as in the embodiment of FIG. 19 (b). When the All ACK capable indicator is 0 as shown in the embodiment of FIG. 19 (c), even if the receiver receives an A-MPDU to which fragment level 2 fragmentation is applied, the receiver receives a bitmap indicating whether to receive a sequence unit. It cannot transmit a BA frame that contains it.

The processing power for the receiver to process the All ACK may be different from that needed for the receiver to process a bitmap indicating whether or not the receiver has received the sequence unit. Specifically, if the receiver can process a bitmap indicating whether or not to receive the sequence unit, if the receiver can process the All ACK, but if the receiver can process a bitmap indicating whether to receive the sequence unit, the receiver is All ACK May not be able to process it. Accordingly, the wireless communication terminal can 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 zero. In this case, the receiver may transmit a BA frame including a bitmap indicating whether a unit is received. In addition, in the embodiment of FIG. 20C, 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 ACK Capable indicator per sequence is also 1. At this time, the receiver may transmit All ACK.

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

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

In addition, the sender 2101 may transmit a plurality of TID A-MPDUs. At this time, the sender 2101 has an MPDU having a TID corresponding to the primary AC based on the maximum length that the A-MPDU may have in the transmission opportunity, and a non-primary TID different from the TID corresponding to the primary AC. An A-MPDU may be generated by collecting MPDUs having an AC TID. 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 is stored within the maximum length that the A-MPDU may have in the transmission opportunity. It is possible to insert the MPDU having. In a specific embodiment, the sender 2101 may insert an MPDU having a non-primary AC TID into the A-MPDU based on a 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 the AC of the MPDU that has acquired the transmission opportunity. For example, the sender 2101 generates an A-MPDU by collecting 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. In addition, the transmitter 2101 may generate an A-MPDU by collecting at least one of an MPDU having a TID corresponding to the primary AC, a management frame, and a control frame. In more detail, the transmitter 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. In more detail, the transmitter 2101 may insert at least one of a management frame and a 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 transmitter 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 the TID corresponding to the primary AC. Priority can be inserted into the A-MPDU and transmitted. In addition, the sender 2101 aggregates MPDUs having TIDs corresponding to primary ACs, management frames / control frames, and MPDUs having non-primary AC TIDs corresponding to ACs having a higher user priority than primary ACs. A-MPDU can be generated. Specifically, the transmitter 2101 preferentially inserts a management frame or control frame into the A-MPDU, and inserts an MPDU having a TID corresponding to primary AC and an MPDU having a non-primary AC TID into the A-MPDU. can do. At this time, the transmitter 2101 inserts all the MPDUs having the TID corresponding to the primary AC stored in the buffer into the A-MPDU as described above, and the non-transfer within the maximum length that the A-MPDU can have at the corresponding transmission opportunity. It is possible to insert an MPDU with a primary AC TID.

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

The sender 2101 may manage information about the fragment for each combination of the receiver, the traffic identifier (TID), and the sequence number. The sender 2101 may generate a new fragment based on the information about the fragment. In more detail, the sender 2101 may determine a fragmentation start pointer of a new fragment based on the information related to the fragment. Also, the sender 2101 may assign a fragment number to a new fragment based on the information related to the fragment. In this case, the information about the fragment may include information about the start pointer indicating the point where the fragmentation starts and information about the fragment number. Specific operations of the transmitter 2101 may be the same as the embodiments described with reference to FIG. 12.

In addition, the transmitter 2101 may insert a sequence number corresponding to the fragment into the fragment as in the embodiments described with reference to FIGS. 9 through 10.

In another specific embodiment, the sender 2101 may store all fragments of the corresponding MSDU previously generated until the last fragment of the MSDU is generated. The sender 2101 may generate a new fragment based on all fragments of the corresponding MSDU previously generated. In more detail, the sender 2101 may determine a fragmentation start pointer of a new fragment based on all fragments of the corresponding MSDU previously generated. In addition, the sender 2101 may assign a fragment number to a new fragment based on all fragments of the corresponding MSDU previously generated. Specific operations of the transmitter 2101 may be the same as the embodiments described with reference to FIG. 13.

In another specific embodiment, the sender 2101 may generate all the fragments of any one MSDU together. In more detail, the sender 2101 may generate all fragments for one MSDU within the same transmission opportunity. Specific operations of the transmitter 2101 may be the same as the embodiments described with reference to FIG. 14.

In addition, the sender 2101 may signal information indicating whether the sender can process a particular ACK type. In more detail, the sender 2101 may transmit an All ACK capable indicator indicating whether the sender can process an All ACK.

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

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

Although the present invention has been described using the WLAN communication as an example, the present invention is not limited thereto and may be equally applicable to other communication systems such as cellular communication. In addition, while the methods, apparatus, and systems of the present invention have been described with reference to specific embodiments, some or all of the components, operations of the present invention may be implemented using a computer system having a general hardware architecture.

Features, structures, effects, and the like 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, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

Although the above description has been made with reference to the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains are not illustrated above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims

In a wireless communication terminal communicating wirelessly,

A transceiver; And

Includes a processor,

The processor is

Transmitting an aggregate-MAC protocol data unit (A-MPDU) including a fragment to a receiver using the transceiver;

Wireless communication terminal.
In claim 1,

The processor is

Manage information about the fragment for each combination of a receiver, a traffic identifier (TID), and a sequence number,

Generating a new fragment based on the information about the fragment

Wireless communication terminal.
In claim 2,

The information about the fragment

Contains information about the start pointer and the fragment number that indicates where the fragmentation begins.

Wireless communication terminal.
In claim 1,

The processor is

Save all fragments of the previously created MSDU until the last fragment of the MAC service data unit (MSDU) is created,

Generating a new fragment based on all fragments of the previously created MSDU.

Wireless communication terminal.
In claim 1,

The processor is

To generate all fragments for a single MSDU within the same transmission opportunity

Wireless communication terminal.
In claim 1,

The processor is

Transmitting capability information indicating whether the transmission / reception unit can process a bitmap indicating whether data in a sequence unit is received.

Wireless communication terminal.
In claim 6,

The processor is

Transmitting the capability information in a link establishment procedure with the receiver;

Wireless communication terminal.
In a wireless communication terminal communicating wirelessly,

A transceiver; And

Includes 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),

Inserting into the A-MPDU an MPDU having a non-primary AC TID which is a different TID from the TID corresponding to the primary AC based on a user priority corresponding to the TID,

Sending the A-MPDU to the receiver using the transceiver

Wireless communication terminal.
In claim 8,

The processor is

Inserting the MPDU having the non-primary AC TID into the A-MPDU based on the maximum number of TIDs the A-MPDU may have

Wireless communication terminal.
In claim 8,

The processor is

Inserting the MPDU with the non-primary AC TID into the A-MPDU based on the maximum length that the A-MPDU may have in the transmission opportunity.

Wireless communication terminal.
In claim 10,

The processor is

Insert all MPDUs having a TID corresponding to the primary AC stored in a buffer into an A-MPDU, and the non- corresponding to an AC having a user priority higher than the user priority 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 8,

The processor is

Inserting a management frame or control frame into the A-MPDU

Wireless communication terminal.
In the operation method of the wireless communication terminal to communicate wirelessly

Generating fragments by dividing a MAC Protocol Data Unit (MPDU), an Aggregate-MAC Service Data Unit (A-MSDU) or a Management Protocol Data Unit (MMPDU); And

Sending an A-MPDU containing the fragment to a receiver;

How it works.
In claim 13,

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;

How it works.
The method of claim 14,

The information about the fragment

Contains information about the start pointer and the fragment number that indicates where the fragmentation begins.

How it works.
The method of claim 14,

Storing all fragments of the previously created MSDU until the last fragment of the MSDU is created; And

Generating a new fragment based on all fragments of the previously generated corresponding MSDU;

How it works.
The method of claim 14,

Generating all fragments for any one MSDU within the same transmission opportunity

How it works.
The method of claim 14,

Transmitting capability information indicating whether a bitmap indicating whether data can be received in a sequence unit can be processed using the same;

How it works.
In the operation method of the wireless communication terminal to communicate wirelessly

Inserting an MPDU having a TID corresponding to the primary AC into an Aggregate-MAC Protocol Data Unit (A-MPDU);

Inserting, in the A-MPDU, an MPDU having a non-primary AC TID which is a different TID from a TID corresponding to the primary AC based on a user priority corresponding to a TID; And

Transmitting the A-MPDU to a receiver;

How it works.
The method of claim 19,

Inserting the MPDU having the non-primary AC TID into the A-MPDU

Inserting an MPDU with the non-primary AC TID into the A-MPDU based on the maximum length the A-MPDU may have in the transmission opportunity.

How it works.