CN114866197A

CN114866197A - Wireless communication method using aggregated MPDU and wireless communication terminal using the same

Info

Publication number: CN114866197A
Application number: CN202210231436.6A
Authority: CN
Inventors: 安佑真; 孙周亨; 郭真三; 高建重
Original assignee: SK Telecom Co Ltd; Wilus Institute of Standards and Technology Inc
Current assignee: SK Telecom Co Ltd; Wilus Institute of Standards and Technology Inc
Priority date: 2016-06-14
Filing date: 2017-06-14
Publication date: 2022-08-05
Anticipated expiration: 2037-06-14
Also published as: CN109314882A; KR20220034915A; KR102411787B1; CN114900270A; KR20190008537A; KR102567626B1; WO2017217766A1; KR20220031144A; CN114884628A; KR102371756B1; CN114866197B; KR102415048B1; CN109314882B; KR20220098042A

Abstract

A wireless communication method using an aggregated MPDU and a wireless communication terminal using the same are disclosed. A wireless communication terminal that performs wireless communication, the wireless communication terminal comprising: a transmitting/receiving unit; and a processor. The processor transmits an a-MPDU for transmitting a plurality of MPDUs to a receiver by using a transmission/reception unit.

Description

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

The application is a divisional application of a patent application with the application number 201780036770.3(PCT/KR2017/006210) of which the international application date of 2018, 12 and 13 is filed in China patent office of 2017, 6 and 14, and the invention is named as a wireless communication method using aggregated MPDUs and a wireless communication terminal using the method.

Technical Field

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

Background

In recent years, as the supply of mobile devices has expanded, wireless communication technologies that can provide fast wireless internet services to mobile devices have received significant public attention. Wireless communication technologies allow mobile devices, including smart phones, smart tablets, laptop computers, portable multimedia players, embedded devices, etc., to wirelessly access the internet in a home or business or specific service provision area.

One of the most well-known wireless communication technologies is a wireless LAN technology. Since the use of a frequency of 2.4GHz to support the original wireless LAN technology, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technical standards. First, IEEE 802.11b supports a communication speed of up to 11Mbps when using a frequency of a 2.4GHz band. IEEE 802.11a commercialized after IEEE 802.11b uses frequencies not in the 2.4GHz band but in the 5GHz band, reduces the influence of interference compared to the obviously congested frequencies in the 2.4GHz band, and improves communication speed up to a maximum of 54Mbps by using an Orthogonal Frequency Division Multiplexing (OFDM) technique. However, IEEE 802.11a has a disadvantage in that the communication distance is shorter than IEEE 802.11 b. Further, IEEE 802.11g uses a frequency of a 2.4GHz band similarly to IEEE 802.11b to realize a communication speed of 54Mbps at maximum and satisfy backward compatibility to be clearly noticed by the public, and further, is superior to IEEE 802.11a in terms of a communication distance.

Further, as a technical standard established in order to overcome the limitation of the communication speed pointed out as a weakness in the wireless LAN, IEEE 802.11n has been provided. The IEEE 802.11n goals are to improve the speed and reliability of the network and to extend the operating distance of the wireless network. In more detail, IEEE 802.11n supports a High Throughput (HT) with a data processing speed of 540Mbps or more at maximum, and further, a Multiple Input Multiple Output (MIMO) technique using a plurality of antennas on both sides of a transmitting unit and a receiving unit based on the plurality of antennas in order to minimize transmission errors and optimize a data speed. In addition, the standard may use an encoding scheme that transmits multiple copies overlapping each other in order to improve data reliability.

As the provision of wireless LANs is active and further applications using the wireless LANs diversify, the need for a new wireless LAN system for supporting a higher throughput (very high throughput (VHT)) than the data processing speed supported by IEEE 802.11n has been receiving public attention. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160MHz) of 5GHz frequency. The IEEE 802.11ac standard is defined only within the 5GHz band, but the original 11ac chipset will even support operation in the 2.4GHz band for backward compatibility with existing 2.4GHz band products. Theoretically, according to this standard, the wireless LAN speed of a plurality of stations can reach 1Gbps at maximum and the maximum single link speed can reach 500Mbps at maximum. This is achieved by extending the concept of wireless interfaces accepted by 802.11n, such as wider radio frequency bandwidth (maximum 160MHz), more MIMO spatial streams (maximum 8), multi-user MIMO and high density modulation (maximum 256 QAM). In addition, as a scheme for transmitting data by using a 60GHz band instead of the existing 2.4GHz/5GHz band, IEEE 802.11ad has been provided. IEEE 802.11ad is a transmission standard that provides a speed of up to 7Gbps by using a beamforming technique and is suitable for a high bit rate moving image stream such as mass data or uncompressed HD video. However, since the 60GHz band is difficult to pass through an obstacle, it is disadvantageous in that the 60GHz band can be used only between devices within a short distance space.

Meanwhile, in recent years, as a next-generation wireless communication technology standard after 802.11ac and 802.11ad, discussion is continuously being made on providing a high-efficiency and high-performance wireless communication technology in a high-density environment. That is, in the next-generation wireless communication technology environment, it is required to provide communication with high frequency efficiency indoors/outdoors in the presence of high-density terminals and base terminals, and various technologies for realizing the communication are required.

In particular, as the number of devices using wireless communication technology increases, it is necessary to efficiently use a predetermined channel. Therefore, what is needed is a technique that can efficiently use bandwidth by simultaneously transmitting data between a plurality of terminals and a base terminal.

Disclosure of Invention

Technical problem

An object of an embodiment of the present invention is to provide a wireless communication terminal using an aggregated MPDU.

Technical scheme

According to an embodiment of the present invention, a wireless communication terminal for wireless communication includes: a transceiver; and a processor, wherein the processor transmits an aggregated MAC protocol data unit (a-MPDU) including fragments to a recipient by using the transceiver.

The processor may be configured to: information on the fragment is managed by each combination of a recipient, a Traffic Identifier (TID), and a sequence number, and a new fragment is generated based on the information on the fragment.

The information on the clip may be configured to include information on a start point of a point indicating a start of the clip and information on a clip number.

The processor may be configured to: all fragments of a corresponding previously generated MSDU are stored until a last fragment of a MAC Service Data Unit (MSDU) is generated, and a new fragment is generated based on all fragments of the corresponding previously generated MSDU.

The processor may be configured to generate all fragments for one MSDU within the same transmission opportunity.

The processor may be configured to: capability information indicating whether the wireless communication terminal is capable of processing a bitmap indicating whether to receive data in sequence units is transmitted by using the transceiver.

The processor may be configured to send the capability information during a link establishment with the recipient.

According to an embodiment of the present invention, a wireless communication terminal for wireless communication includes: a transceiver; and a processor, wherein the processor is configured to insert MAC Protocol Data Units (MPDUs) having TIDs corresponding to a master Access Category (AC) into an aggregated MPUD (a-MPDU), insert MPDUs having non-master AC TIDs that are TIDs different from the TIDs corresponding to the master AC into the a-MPDU based on user priorities corresponding to the TIDs, and transmit the a-MPDUs to a recipient by using the transceiver.

The processor may be configured to insert an MPDU having a non-master AC TID into the a-MPDU based on a maximum number of TIDs that the a-MPDU can have.

The processor may be configured to insert an MPDU having a non-master AC TID into the a-MPDU based on a maximum length that the a-MPDU can have in a corresponding transmission opportunity.

The processor may be configured to: all MPDUs having TIDs corresponding to the master AC stored in the buffer are inserted into the a-MPDUs, and MPDUs having non-master AC TIDs corresponding to ACs having a higher user priority than the master ACK within a maximum length are inserted into the a-MPDUs.

The processor may be configured to insert a management frame or a control frame into the a-MPDU.

According to an embodiment of the present invention, an operation method of a wireless communication terminal for wireless communication includes: generating fragments by partitioning MAC Protocol Data Units (MPDUs), aggregated MAC service data units (A-MSDUs), or management protocol data units (MMPDUs); and transmitting the a-MPDU including the fragments to a receiver.

The method may further comprise: managing information on the fragments by each combination of a recipient, a Traffic Identifier (TID), and a sequence number; and generating a new segment based on the information about the segment.

The information on the clip may include information on a start point of a point indicating a start of the clip and information on a clip number.

The method may further comprise: storing all fragments of a corresponding previously generated MSDU until a last fragment of a MAC Service Data Unit (MSDU) is generated; and generating new fragments based on all fragments of the corresponding previously generated MSDU.

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

The method may further include transmitting, by using the transceiver, capability information indicating whether the wireless communication terminal is capable of processing a bitmap indicating whether to receive data in sequence units.

According to an embodiment of the present invention, an operation method of a wireless communication terminal includes: inserting an MPDU having a TID corresponding to a master AC into an aggregated MAC protocol data unit (A-MPDU); inserting, based on the user priority corresponding to the TID, an MPDU having a non-primary Access Category (AC) TID that is a different TID than the TID corresponding to the primary ACI in the A-MPDU; and transmitting the a-MPDU to a recipient.

Inserting the MPDU having the non-master AC TID into the a-MPDU may include: an MPDU having a non-master AC TID is inserted into the a-MPDU based on the maximum length that the a-MPDU can have in the corresponding transmission opportunity.

Advantageous effects

Embodiments of the present invention provide a wireless communication method using an aggregated MPDU and a wireless communication terminal using the same.

Drawings

Fig. 1 shows a wireless LAN system according to an embodiment of the present invention.

Fig. 2 shows a wireless LAN system according to another embodiment of the present invention.

Fig. 3 shows a block diagram illustrating a configuration of a station according to an embodiment of the inventive concept.

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

Fig. 5 illustrates a procedure in which a station sets an access point and a link according to an embodiment of the present invention.

Fig. 6 illustrates a method for transmitting a block ack (ba) frame for an aggregated MAC protocol data unit (a-MPDU) according to an embodiment of the present invention.

Fig. 7 illustrates a wireless communication terminal transmitting an a-MPDU having a plurality of TIDs according to an embodiment of the present invention.

Fig. 8 illustrates a format of a multi-STA block ACK frame according to an embodiment of the present invention.

Fig. 9 illustrates allocation of sequence numbers to MSDUs by a wireless communication terminal in a dynamic fragmentation operation according to an embodiment of the present invention.

Fig. 10 illustrates a wireless communication terminal assigning sequence numbers to MSDUs in a dynamic fragmentation operation according to another embodiment of the present invention.

Fig. 11 illustrates assigning of a fragment number to a fragment in a dynamic segmentation operation of a wireless communication terminal according to an embodiment of the present invention.

Fig. 12 illustrates assigning of a fragment number to a fragment in a dynamic segmentation operation of a wireless communication terminal according to another embodiment of the present invention.

Fig. 13 illustrates assigning of fragment numbers to fragments in a dynamic segmentation operation of a wireless communication terminal according to another embodiment of the present invention.

Fig. 14 illustrates assigning of a fragment number to a fragment in a dynamic segmentation operation of a wireless communication terminal according to another embodiment of the present invention.

Fig. 15 illustrates a method for transmitting a block ack (ba) frame for an aggregated MAC protocol data unit (a-MPDU) according to an embodiment of the present invention.

Fig. 16 illustrates a wireless communication terminal transmitting an a-MPDU having a plurality of TIDs according to an embodiment of the present invention.

Fig. 17 illustrates a method of configuring a multi-TID a-MPDU by a wireless communication terminal according to an embodiment of the present invention.

Fig. 18 illustrates a format of a multi-STA block ACK frame according to an embodiment of the present invention.

Fig. 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 at fragmentation level 2.

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

Detailed Description

Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Parts that are not relevant to the description are omitted in the drawings in order to clearly describe the present invention, and like reference numerals refer to like elements throughout.

Further, when it is described that an article includes (or includes or has) some elements, it should be understood that it may include (or include or have) only those elements or it may include (or include or have) other elements as well as those elements, if not specifically limited.

The present application claims priority and benefit of korean patent application nos. 10-2016 0074090(2016.06.14), 10-2016 0093811(2016.07.23), and 10-2016 0104407(2016.08.17) filed by the korean intellectual property office, and embodiments and mentioned items described in the respective applications are included in the detailed description of the present application.

Fig. 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. For convenience of description, embodiments of the present invention are described through a wireless LAN system. The wireless LAN system includes one or more Basic Service Sets (BSSs) and the BSSs represent a set of devices that successfully synchronize with each other to communicate with each other. In general, BSSs may be classified as infrastructure BSSs and independent BSSs (ibss) and fig. 1 illustrates the infrastructure BSSs therebetween.

As illustrated in fig. 1, infrastructure BSSs (BSS1 and BSS2) include one or more stations STA1, STA2, STA3, STA4, and STA5, access points PCP/AP-1 and PCP/AP-2 as stations providing a distribution service, and a Distribution System (DS) connecting the plurality of access points PCP/AP-1 and PCP/AP-2.

A Station (STA) is a predetermined device including a Medium Access Control (MAC) following a procedure of the IEEE 802.11 standard and a physical layer interface for a wireless medium, and broadly includes a non-access point (non-AP) station and an Access Point (AP). In addition, in the present specification, the term "terminal" may be used to refer to a concept including a wireless LAN communication device such as a non-AP STA or an AP or both terms. The station for wireless communication comprises a processor and a transceiver and, according to this embodiment, may further comprise a user interface unit and a display unit. The processor may generate a frame to be transmitted through a wireless network or process a frame received through the wireless network, and further, perform various processes for controlling the station. Further, the transceiver is functionally connected with the processor and transmits and receives frames through a wireless network for the station.

An Access Point (AP) is an entity that provides access to a Distribution System (DS) via a wireless medium for stations associated therewith. In the infrastructure BSS, communication between non-AP stations is performed via an AP in principle, but when a direct link is configured, direct communication can be achieved even between non-AP stations. Meanwhile, in the present invention, an AP is used as a concept including a personal BSS coordination point (PCP) and may include a concept broadly including a centralized controller, a Base Station (BS), a node B, a Base Transceiver System (BTS), and a site controller.

A plurality of infrastructure BSSs may be connected to each other through a Distribution System (DS). In this case, a plurality of BSSs connected through a distribution system is called an Extended Service Set (ESS).

Fig. 2 illustrates an independent BSS as a wireless communication system according to another embodiment of the present invention. For convenience of description, another embodiment of the present invention is described through a wireless LAN system. In the embodiment of fig. 2, a repeated description of the same or corresponding portions as those of the embodiment of fig. 1 will be omitted.

Since the BSS3 illustrated in fig. 2 is an independent BSS and does not include an AP, none of the stations STA6 and STA7 are connected to an AP. The independent BSS is not licensed to access the distribution system and forms a complete network. In the independent BSS, the respective stations STA6 and STA7 may be directly connected to each other.

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

As illustrated in fig. 3, a station 100 according to an embodiment of the present invention may include a processor 110, a transceiver 120, a user interface unit 140, a display unit 150, and a memory 160.

First, the transceiver 120 transmits and receives a wireless signal such as a wireless LAN physical layer frame and the like and may be embedded in the station 100 or provided externally. According to this embodiment, the transceiver 120 may include at least one transmitting and receiving module using different frequency bands. For example, the transceiver 120 may include transmission and reception modules having different frequency bands such as 2.4GHz, 5GHz, and 60 GHz. According to an embodiment, the station 100 may include a transmission and reception module using a frequency band of 6GHz or higher and a transmission and reception module using a frequency band of 6GHz or lower. The respective transmitting and receiving modules may perform wireless communication with the AP or the external station according to a wireless LAN standard of a frequency band supported by the corresponding transmitting and receiving modules. Transceiver 120 may operate only one transmit and receive module at a time or multiple transmit and receive modules simultaneously together depending on the capabilities and requirements of station 100. When the station 100 includes a plurality of transmitting and receiving modules, each transmitting and receiving module may be implemented by a separate element or a plurality of modules may be integrated into one chip.

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

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

The processor 110 of the present invention can execute various commands or programs and process data in the station 100. In addition, the processor 110 may control the respective units of the station 100 and control data transmission/reception between the units. According to an embodiment of the present invention, the processor 110 may execute a program for accessing the AP stored in the memory 160 and receive a communication configuration 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 access to the AP based on the information on the priority condition of the station 100. The processor 110 of the present invention may represent a main control unit of the station 100 and according to this embodiment, the processor 110 may represent a control unit for individually controlling certain components of the station 100 (e.g., the transceiver 120, etc.). The processor 110 may be a modulator and/or demodulator that modulates wireless signals transmitted to the transceiver 120 and demodulates wireless signals received from the transceiver 120. The processor 110 controls various operations of wireless signal transmission/reception of the station 100 according to an embodiment of the present invention. Detailed embodiments thereof will be described below.

The station 100 illustrated in fig. 3 is a block diagram in accordance with an embodiment of the present invention, in which individual blocks are illustrated as logically distinct elements of the device. Thus, the elements of the device may be mounted in a single chip or in multiple chips depending on the design of the device. For example, the processor 110 and the transceiver 120 may be integrated into a single chip or implemented as separate chips. In addition, in an embodiment of the present invention, some components of the station 100, such as the user interface unit 140 and the display unit 150, may be optionally provided in the station 100.

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

As illustrated in fig. 4, an 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, among the components of the AP 200, a repeated description of the same or corresponding parts as those of the station 100 of fig. 2 will be omitted.

Referring to fig. 4, an AP 200 according to the present invention includes a transceiver 220 for operating a BSS in at least one frequency band. As depicted in the embodiment of fig. 3, the transceiver 220 of the AP 200 may also include multiple transmit and receive modules using different frequency bands. That is, the AP 200 according to an embodiment of the present invention may include two or more transmission and reception modules among different frequency bands (e.g., 2.4GHz, 5GHz, and 60GHz) together. Preferably, the AP 200 may include a transmission and reception module using a 6GHz or higher frequency band and a transmission and reception module using a 6GHz or lower frequency band. The respective transmitting and receiving modules may perform wireless communication with the stations according to a wireless LAN standard of a frequency band supported by the corresponding transmitting and receiving modules. Transceiver 220 may operate only one transmitting and receiving module at a time or multiple transmitting and receiving modules simultaneously together depending on the capabilities and requirements of AP 200.

Next, the memory 260 stores a control program used in the AP 200 and various resultant data. The control program may comprise an access program for managing access of the station. In addition, the processor 210 may control the respective units of the AP 200 and control data transmission/reception between the units. According to an embodiment of the invention, processor 210 may execute a program for accessing stations stored in memory 260 and transmit communication configuration messages for one or more stations. In this case, the communication configuration message may include information on an access priority condition of the corresponding station. In addition, the processor 210 performs access configuration according to an access request of a station. Processor 210 may be a modulator and/or demodulator that modulates wireless signals transmitted to transceiver 220 and demodulates wireless signals received from transceiver 220. The processor 210 controls various operations such as radio signal transmission/reception of the AP 200 according to the first embodiment of the present invention. Detailed embodiments thereof will be described below.

Fig. 5 is a diagram schematically illustrating a process in which a STA sets up a link with an AP.

Referring to fig. 5, a link between the STA 100 and the AP 200 is generally set 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. The method for performing scanning includes a passive scanning method in which the AP 200 obtains information by using a beacon message (S101) that is periodically transmitted, and an active scanning method in which the STA 100 transmits a probe request to the AP (S103) and obtains access information by receiving a probe response from the AP (S105).

The STA 100, which successfully receives the wireless access information in the scanning step, performs the authentication step by transmitting an authentication request (S107a) and receiving an authentication response from the AP 200 (S107 b). After the authentication step is performed, the STA 100 performs the association step by transmitting an association request (S109a) and receiving an association response from the AP 200 (S109 b).

Meanwhile, an authentication step (S111) based on 802.1X and an IP address obtaining step (S113) by DHCP may be additionally performed. In fig. 5, the authentication server 300 is a server that handles 802.1X-based authentication for the STA 100 and may exist in physical association with the AP 200 or exist as a separate server.

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

The wireless communication terminal according to an embodiment of the present invention can transmit and receive data using a data unit, which is a data processing unit of each layer. Specifically, the wireless communication terminal may generate a Media Access Control (MAC) protocol data unit (MPDU) in a MAC layer and a Physical Protocol Data Unit (PPDU) in a physical layer. In addition, a wireless communication terminal receiving data may receive a PPDU and obtain an MPDU from the PPDU. By this operation, the wireless communication terminal can increase the reliability and efficiency of data transmission. For convenience of explanation, a wireless communication terminal that transmits data is referred to as an initiator, and a wireless communication terminal that receives data is referred to as a recipient. Specific operations of the initiator and the recipient will be described with reference to fig. 6 to x.

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

In the MAC layer, the wireless communication terminal receives a MAC Service Data Unit (MSDU) from 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 adds a MAC layer header to the MSDU to generate an MPDU. Specifically, when the wireless communication terminal obtains a transmission opportunity, the wireless communication terminal may generate an MPDU by adding a MAC header to the MSDU. At this time, the wireless communication terminal can obtain a transmission opportunity through a contention procedure. Specifically, when the wireless medium is idle, the wireless communication terminal may start a contention procedure for channel access. In addition, the wireless communication terminal may obtain 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 by the MAC layer through the PPDU. Specifically, the wireless communication terminal may transfer the MAC du from the MAC layer to the physical layer. The wireless communication terminal may generate the PPDU by adding a physical layer header to the MPDU in the physical layer.

The wireless communication terminal uses the sequence number to manage the transmission of the MSDU. Specifically, the wireless communication terminal assigns a sequence number to each MSDU. In addition, the wireless communication terminal assigns a new sequence number to a new MSDU each time the MSDU is transmitted. In particular, each time a new MSDU is transmitted by the wireless communication terminal, the wireless communication terminal may assign a sequence number to the MSDU that is one greater than the previously assigned sequence number. At this time, the wireless communication terminal may assign a sequence number to each combination of the Receiver Address (RA) and the Traffic Identifier (TID). Specifically, the wireless communication terminal may determine a 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 the SNS. Thus, the wireless communication terminal can manage MSDUs having the same RA and the same TID in one sequence number space. By this operation, the wireless communication terminal can efficiently manage the sequence numbers assigned to the MSDUs.

In addition, the wireless communication terminal manages transmission and retransmission by the MPDU unit. Thus, the wireless communication terminal stores the MPDU until an ACK for the MPDU is received. Specifically, the wireless communication terminal buffers the MPDU until an ACK is received for the MPDU. When the wireless communication terminal receives the ACK for the MPDU, the wireless communication terminal may delete the stored MPDU. In addition, when the wireless communication terminal receives information indicating that the receiver has not received the MPDU, the wireless communication terminal may retransmit the 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 (BA) frame, and a multi-STA BA frame. Further, the wireless communication terminal stores the MSDU in a buffer. The wireless communication terminal deletes MSDUs successfully transmitted to the receiver from the buffer.

In the embodiment of fig. 5, the first station STA1 sends an MSDU with TID of 2 to a recipient with RA of 3. In this case, the sequence number value stored in the SNS is 30, where RA of the first station STA1 is 3 and TID is 2. Thus, the first station STA1 allocates 31, 32 and 33 as sequence numbers to three MSDUs with TID of 2 for the recipient with RA of 3, respectively. The first station STA1 generates an aggregate MPDU (a-MPDU) including three MSDUs. The first station STA1 transmits the generated a-MPDU using a PPDU. The first station STA1 receives a BA frame that includes a bitmap indicating receipt of MSDUs corresponding to sequence

numbers

31 and 33. Accordingly, the first station STA1 deletes MSDUs corresponding to the

sequence numbers

31 and 33 from the buffer.

If the size of the MSDU is large, the wireless communication terminal may fragment to transmit the MSDU. If the size of the MSDU is too large, the likelihood of transmission failure may increase. Specifically, the wireless communication terminal may fragment and transmit at least one of an MSDU, an aggregate (a) -MSDU, and a management protocol data unit (MMPDU). For convenience of explanation, a portion of an MSDU, a portion of an a-MSDU, or a portion of an MMPDU generated by fragmentation is referred to as a fragment.

In particular, the wireless communication terminal may fragment at least one of the MSDU, A-MSDU, and MMPDU to generate a plurality of fragments. At this time, the wireless communication terminal may transmit the generated plurality of fragments by using the plurality of MPDUs. In addition, the wireless communication terminal receiving the plurality of fragments may de-fragment the plurality of fragments to obtain at least one of one MSDU, one A-MSDU, and one MMPDU. At this time, the MPDU may be an S-MPDU or an A-MPDU. The wireless communication terminal may generate the segments other than the last segment in a fixed size. In addition, the wireless communication terminal may generate a fragment without a fixed size. Segments with a fixed segment size except for the last segment are referred to as static segments. Segments whose size is not fixed are called dynamic segments. The static segmentation will be described in detail with reference to fig. 7 and will be described in detail with reference to fig. 8.

Fig. 7 illustrates a wireless communication terminal transmitting data using static segmentation according to an embodiment of the present invention.

The wireless communication terminal assigns the same sequence number to all fragments that fragment the same MSDU. Further, the wireless communication terminal assigns a Fragment Number (FN) to the fragment. Specifically, the wireless communication terminal may assign a new fragment number each time a fragment is generated by fragmenting the same MSDU. The wireless communication terminal may assign a segment number for each combination of the same RA, TID, and sequence number. In particular embodiments, a wireless communication terminal may assign a fragment number increased by 1 for each fragment generated from the same MSDU. In this case, the wireless communication terminal may assign a fragment number starting from 0 to the fragment. Further, the wireless communication terminal may generate fragments when starting a transmission sequence of MSDUs. The wireless communication terminal stores the fragment after transmitting the fragment using the MPDU. In particular, the wireless communication terminal may buffer the fragments after transmitting the fragments using the MPDU. By this operation, the wireless communication terminal can distinguish the segments and efficiently manage the segments.

The wireless communication terminal may continuously transmit each of a plurality of fragments generated from the same MSDU as one MPDU. This transmission method may be referred to as a burst of fragments. In the burst transmission of fragments, when the wireless communication terminal receives an ACK for a previously transmitted MPDU, the wireless communication terminal may transmit the next MPDU within a predetermined time after receiving the ACK without returning a transmission opportunity. At this time, the predetermined time may be a short interframe space (SIFS). The wireless communication terminal may repeat this process until all fragments generated from the same MSDU are transmitted. In a burst transmission of fragments, the wireless communication terminal may generate one fragment at a time. In particular, a fragment may be generated upon receiving an ACK for a previously transmitted MPDU. In the present embodiment, the wireless communication terminal transmits only an MPDU including one fragment at a time, and may not transmit an a-MPDU in which a plurality of MPDUs are transmitted. When the wireless communication terminal fails to receive an ACK for a previously transmitted MPDU in a fragment burst transmission, the wireless communication terminal returns a transmission opportunity. At this time, the wireless communication terminal acquires a transmission opportunity again through a contention procedure and retransmits the MPDU including the previously transmitted fragment. In particular, the wireless communication terminal may retransmit the MPDU including the stored fragments. At this time, the stored segment may indicate a cached segment as described above.

In the fragment burst transmission, the wireless communication terminal generates a new fragment upon receiving ACK of the previously transmitted MPDU as described above. At this time, the wireless communication terminal assigns a clip number to the new clip based on the stored clip. Specifically, the wireless communication terminal may assign a number larger than the number of the segment of the stored segment to the segment number of the new segment. At this time, when the first fragment is generated from the MSDU, the wireless communication terminal may assign 0 to the fragment number of the corresponding fragment. In addition, the wireless communication terminal may determine a starting point of the MSDU based on the size of the fragment to generate the fragment. The wireless communication terminal generates a fragment and deletes the stored fragment. In the present embodiment, the wireless communication terminal can generate a new clip using only the stored clip and assign a clip number. Accordingly, the wireless communication terminal may not use a tracking space for tracking a segment number assignment and a segment start point.

In the embodiment of fig. 7, the first station STA1 fragments one MSDU into four fragments and transmits the fragments. The first station STA1 assigns a sequence number of the first fragment 31.0 to 31 and a fragment number to 0 because the sequence number of the previously transmitted MSDU is 30. 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 segment 31.1 based on the buffered segments. In addition, the first station STA1 assigns the fragment number of the second fragment 31.1 to 1 because the fragment number of the cache fragment is zero. 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 segment 31.2 based on the buffered segments. Further, the first station STA1 assigns the fragment number of the third fragment 31.2 to 2 because the fragment number of the cache fragment is 1. The first station STA1 transmits an MPDU including the third fragment 31.2, and the first station STA1 does not receive an ACK frame including the MPDU of the third fragment 31.2.

Therefore, the first station STA1 returns a transmission opportunity and obtains a new transmission opportunity through a contention procedure. The first station transmits the MPDU including the third buffer segment 31.2 again. The first station STA1 receives an ACK frame including the MPDU of the third fragment 31.2. The first station STA1 determines the starting point of the fourth segment 31.3 based on the buffered segments. Further, the first station STA1 assigns the fragment number of the third fragment 31.3 to 3 because the fragment number of the cache fragment is 2. 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.

Fig. 8 illustrates a wireless communication terminal transmitting data using dynamic segmentation according to an embodiment of the present invention.

As described above, the wireless communication terminal may generate a fragment without a fixed size. In addition, the wireless communication terminal may transmit an MPDU including the fragment together with another MPDU. In particular, a wireless communication terminal may transmit an a-MPDU including an MPDU with a fragment of another MPDU.

Further, when dynamic fragmentation is used, the initiator generates fragments according to fragmentation levels and transmits an MPDU including the fragments. At this time, the initiator may determine the segmentation level based on the capabilities of the recipient. At this time, the segmentation level indicates the degree of segmentation that the receiver can receive. The segmentation level may be divided into four levels. Level 0 may indicate that the wireless communication terminal does not support dynamic fragmentation of MSDUs received by the wireless communication terminal. Also, level 1 may indicate that the wireless communication terminal is capable of receiving an MPDU including one fragment. At this time, the MPDU may be a single MPDU that is not aggregated with another MPDU, or an MPDU that is not an a-MPDU. Also, level 2 may indicate that the wireless communication terminal is capable of receiving a-MPDUs, each MSDU including one fragment. In particular, level 2 may indicate that the wireless communication terminal is capable of receiving a-MPDUs with each MSDU including one or fewer fragments. Level 3 may indicate that the wireless communication terminal is capable of receiving a-MPDUs with each MSDU including multiple fragments. In particular, level 3 may indicate that the wireless communication terminal is capable of receiving a-MPDUs comprising four or fewer fragments per MSDU. The initiator and the recipient may signal information about the segmentation level during the link establishment procedure. In addition, the originator and the recipient may negotiate information about the segmentation level in an ADDBA procedure. This will be described in detail with reference to fig. 15 to 20.

In the embodiment of fig. 8, the recipient supports segmentation level 3. In the embodiment of fig. 8, the initiator fragments the MSDU at fragmentation level 2. Thus, the initiator sends an a-MPDU including one fragment of each MSDU to the receiver. At this time, the a-MPDU includes a first fragment 6.0 of an MSDU corresponding to sequence number 6, a first fragment 7.0 of an MSDU corresponding to sequence number 7, a first fragment 8.0 of an MSDU corresponding to sequence number 8, a first fragment 9.0 of an MSDU corresponding to sequence number 9, and a first fragment 10.0 of an MSDU corresponding to sequence number 10. In the embodiment of fig. 8, the initiator fragments the MSDU at fragmentation level 3. Thus, the initiator sends a-MPDUs comprising one or more fragments of different MSDUs to the receiver. At this time, the a-MPDU includes a first fragment 6.0 of the MSDU corresponding to sequence number 6, first and second fragments 7.0 and 7.1 of the MSDU corresponding to sequence number 7, and first and second fragments 8.0 and 8.1 of the MSDU corresponding to sequence number 8.

As described with reference to fig. 7, whenever a new MSDU is transmitted, the wireless communication terminal may assign a new sequence number to the MSDU. In particular, each time a new MSDU is transmitted by the wireless communication terminal, the wireless communication terminal may assign a sequence number to the MSDU that is one greater than the previously assigned sequence number. When the initiator uses static fragmentation, the initiator sends one fragment at a time, sends all fragments of one MSDU, and then sends the new fragment. Therefore, when the wireless communication terminal uses static segmentation, it is not a problem for the wireless communication terminal to insert a sequence number corresponding to a segment into the segment based on the stored segment. 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, first station STA1 transmits to at least one recipient an a-MPDU including MSDU 6.0 corresponding to sequence number 6, MSDU 7.0 corresponding to sequence number 7 and first fragment 8.0 corresponding to MSDU sequence number 8. The first station STA1 receives a BA frame from at least one receiver indicating that MSDU 6.0 corresponding to sequence number 6, MSDU 7.0 corresponding to sequence number 7, and first fragment 8.0 of the MSDU corresponding to sequence number 8 were received.

The first station STA1 transmits an a-MPDU including a MSDU different from the MSDU corresponding to sequence number 8 and a second fragment 8.1 of the MSDU corresponding to sequence number 8. At this time, since the first station STA1 may not transmit all fragments of the MSDU corresponding to the sequence number 8, the previous sequence number managed by the SNS is maintained as 7. Thus, the first station STA1 allocates sequence number 8 to MSDUs other than the MSDU corresponding to sequence number 8. The receiver determines whether the MSDU is repeatedly received based on the sequence number and the fragment number. Thus, in the case of the embodiment of fig. 9, although the receiver receives a new MSDU, the receiver may determine that a duplicate MSDU is received, so that it may send an ACK for the MSDU to the originator and may not forward the MSDU to an upper layer.

When the wireless communication terminal generates a first MPDU including fragments of an MSDU, the wireless communication terminal may increase the sequence number of a previous MSDU. Specifically, when the wireless communication terminal generates the first MPDU including fragments of the MSDU, the wireless communication terminal may increase the previous sequence number managed by the SNS by 1.

In the embodiment of fig. 10, first station STA1 transmits to at least one recipient an a-MPDU including MSDU 6.0 corresponding to sequence number 6, MSDU 7.0 corresponding to sequence number 7 and first fragment 8.0 corresponding to MSDU sequence number 8. The first station STA1 receives a BA frame from at least one receiver indicating that MSDU 6.0 corresponding to sequence number 6, MSDU 7.0 corresponding to sequence number 7, and first fragment 8.0 of the MSDU corresponding to sequence number 8 were received.

The first station STA1 transmits an a-MPDU including MSDU 9.0 corresponding to sequence number 9 and second fragment 8.1 of MSDU corresponding to sequence number 8. When the first station STA1 transmits a first MSDU corresponding to an MSDU of sequence number 8, the first station STA1 sets a previous sequence number managed by the SNS to 8. Thus, although the first station STA1 fails to transmit all fragments of an MSDU corresponding to sequence number 8, the first station STA1 may allocate 9 to a new MSDU.

When the wireless communication terminal uses static segmentation, the wireless communication terminal may determine a segmentation start point of the MSDU based on the last transmitted segmentation. At this time, the fragment start point indicates a point at which the fragment for the fragment starts in the MSDU. This is because the size of the segment other than the last one is fixed. Specifically, if the number of fragments increases from 0 to 1, the wireless communication terminal can determine the start point of the fragments of 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 determine the starting point of the fragmentation of the MSDU based on the fragment number of the last transmitted fragment.

In the embodiment of fig. 11, the first station STA1 sends an a-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and fragments having a TID of 2 to at least one recipient. In this case, the sequence numbers of the two MSDUs 6.0 with TID 1 are 6 and 7, respectively. For one fragment 8.0 with a TID of 1, the sequence number is 8 and the fragment number is 0. Further, the sequence number of one MSID 31.0 with TID 2 is 31. For one fragment 32.0 with a TID of 2, the sequence number is 32 and the fragment number is 0. The first station STA1 receives a BA frame from the recipient indicating an ACK for two MSDUs and a fragment with TID 1 and one MSDU and a fragment with TID 2.

When the first station STA1 sends the remaining fragments of MSDUs with TID of 1 and sequence number of 8 or MSDUs with TID of 2 and sequence number of 32, the first station STA1 may not know the start of each MSDU. Also, the first station SAT 1 may not know which fragment number should be assigned to the fragment to be transmitted.

The wireless communication terminal may manage information about the segments by each combination of recipient, TID, and sequence number. In addition, the wireless communication terminal may generate a new segment based on the information related to the segment. Specifically, the wireless communication terminal may determine a segment start point of the new segment based on the information related to the segment. In addition, the wireless communication terminal may assign a clip number to the new clip based on the information related to the clip. At this time, the information related to the segment may be at least one of information on a segment number and information on a segment start point. Specifically, when the wireless communication terminal uses dynamic segmentation, the wireless communication terminal can manage information on a segment number and information on a segment start point. In certain embodiments, the wireless communication terminal may store the fragment number of the last transmitted fragment. In addition, the wireless communication terminal may store the sum of the sizes of the previously generated segments. In addition, the wireless communication terminal may store information on a segment number and information on a segment start point in the form of a tuple. In a specific embodiment, the wireless communication terminal may use a Fragment Number Space (FNS) for managing information on a fragment number and information on a fragment start point. Specifically, FNSs can be defined as shown in the following table.

TR 1: the cumulative size of fragments that the transmitting STA should buffer acknowledgments from this fragment number space for the assigned fragment number

When the wireless communication terminal generates the last fragment of the corresponding MSDU, the tuple including information on the FNS of the MSDU or the fragment of the MSDU may be deleted.

In the embodiment of fig. 12, the first station STA1 sends an a-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and fragments having a TID of 2 to at least one recipient. In this case, the sequence numbers of the two MSDUs 6.0 and 7.0 with TID of 1 are 6 and 7, respectively. For one fragment 8.0 with a TID of 1, the sequence number is 8 and the fragment number is 0. Further, the sequence number of one MSID 31.0 with TID of 2 is 31. For one fragment 32.0 with a TID of 2, the sequence number is 32 and the fragment number is 0. The first station STA1 receives a BA frame from the recipient indicating an ACK for two MSDUs and a fragment having a TID of 1 and one MSDU and a fragment having a TID of 2.

The first station STA1 maintains a first FNS and a second FNS. At this point, the first FNS stores information for the first recipient's transmission of fragments having a TID of 1 and a sequence number of 8. Specifically, the first FNS stores the sum of the sizes of the fragments with TID 1 and sequence number 8 sent to the first recipient, and the fragment number 0 of the fragment with TID 1 and sequence number 8 last sent to the first recipient. In addition, the second FNS stores information for the second recipient's transmission of fragments having a TID of 2 and a sequence number of 32. Specifically, the second FNS stores the sum of the sizes of the fragments with TID of 2 and sequence number of 32 sent to the second recipient, and the fragment number of 0 of the fragment with TID of 2 and sequence number of 32 sent to the second recipient last. Thus, the first station STA1 determines a segment start point for the first recipient for a segment having a TID of 1 and a sequence number of 8 based on the first FNS. Further, first station STA1 assigns 1 as a fragment number to a fragment having a TID of 1 and a sequence number of 8 based on the first FNS. Thus, the first station STA1 determines a segment start point for the second recipient based on the second FNS with a TID of 2 and a sequence number of 32. Further, first station STA1 assigns 1 as a fragment number to a fragment having TID of 2 and sequence number of 32 for the second recipient based on the second FNS.

In another particular embodiment, the wireless communication terminal may store all fragments of a corresponding previously generated MSDU until the last fragment of the MSDU is generated. In particular, the wireless communication terminal may buffer all fragments of a corresponding previously generated MSDU until the last fragment of the MSDU is generated. The wireless communication terminal may generate a new segment based on the stored segments. In particular, the wireless communication terminal may determine a segment start point of a new segment based on the stored segments. In addition, the wireless communication terminal may assign a clip number to the new clip based on the stored clip. In particular, the wireless communication terminal may store MPDUs including all fragments of a corresponding previously generated MSDU until the last fragment of the MSDU is generated. To this end, the wireless communication terminal may transmit a BAR frame requesting a BA frame only to MSDUs that transmit all fragments to the receiver. This is because the wireless communication terminal may store the MPDU until it receives an ACK from the receiver.

In the embodiment of fig. 13, the first station STA1 sends an a-MPDU including two MSDUs and fragments having a TID of 1, and one MSDU and fragments having a TID of 2 to at least one recipient. In this case, the sequence numbers of the two MSDUs 6.0 and 7.0 with TID of 1 are 6 and 7, respectively. For one fragment 8.0 with a TID of 1, sequence number 8 and fragment number 0. Further, the sequence number of one MSID 31.0 with TID of 2 is 31. For one fragment 32.0 with a TID of 2, the sequence number is 32 and the fragment number is 0. The first station STA1 receives BA frames from the recipient indicating ACKs for two MSDUs and fragments with TID 1 and one MSDU and fragments with TID 2.

At this point, because the first station STA1 does not send all fragments for an MSDU with a TID of 1 and a sequence number of 8, and all fragments for an MSDU with a TID of 2 and a sequence number of 32, the first station STA1 buffers fragments with a TID of 1 and a sequence number of 8, and fragments with a TID of 2 and a sequence number of 32. Thus, the first station STA1 determines a segment start point for a segment having a TID of 1 and a sequence number of 8 based on the buffered segments. 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 buffered fragments. Further, the first station STA1 determines a segment start point for the second recipient's segment with TID of 2 and sequence number of 32 based on the buffered segments. Further, 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 buffered fragments. With this embodiment, the wireless communication terminal can efficiently manage information on a clip without storing any additional information.

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

In the embodiment of fig. 14, the first station STA1 sends an a-MPDU including two MSDUs and fragments having a TID of 1 and one MSDU and fragments having a TID of 2 to at least one recipient. In this case, the sequence numbers of the two MSDUs 6.0 and 7.0 with TID of 1 are 6 and 7, respectively. For one fragment 8.0 with a TID of 1, the sequence number is 8 and the fragment number is 0. Further, the sequence number of one MSID 31.0 with TID 2 is 31. For one fragment 32.0 with a TID of 2, the sequence number is 32 and the fragment number is 0. The first station STA1 receives a BA frame from the recipient indicating an ACK for two MSDUs and a fragment having a TID of 1 and one MSDU and a fragment having a TID of 2.

At this time, the first station STA1 generates three fragments of an MSDU with TID 1 and sequence number 8 at one transmission opportunity. However, the first station STA1 transmits only one segment 8.0 as described above, and transmits the remaining two segments 8.1 and 8.2 in the next transmission opportunity. Additionally, the first station STA1 generates three fragments of an MSDU with a TID of 2 and a sequence number of 32 together at one transmission opportunity. However, the first station STA1 transmits only one fragment 32.0 as described above, and transmits the remaining two fragments 32.1 and 32.2 in the next transmission opportunity. With such an embodiment, the wireless communication terminal can efficiently manage information on a clip without storing additional information or buffering the clip.

A wireless communication terminal may combine multiple MPDUs to generate one a-MPDU. The wireless communication terminal may transmit the generated a-MPDU. A conventional wireless communication terminal combines only MPDUs having the same Traffic Identifier (TID) to generate an a-MPDU. A wireless communication terminal according to an embodiment of the present invention may combine a plurality of MPDUs having different TIDs to generate one a-MPDU. For ease of explanation, an a-MPDU comprising a plurality of MPDUs corresponding to a plurality of different TIDs is referred to as a multi-TID a-MPDU or an a-MPDU having a plurality of TIDs. The wireless communication terminal may transmit the generated a-MPDU. In particular, a wireless communication terminal may transmit an a-MPDU having multiple TIDs using a physical layer protocol data unit (HE PPDU). At this time, the HE PPDU may be an HE multi-user (MU) PPDU. Further, the HE PPDU may be a HE triggered PPDU.

The wireless communication terminal may set parameters related to a-MPDU and BA frame transmission during link setup. The wireless communication terminal may set parameters related to a-MPDUs having multiple TIDs during link setup. In particular, the wireless communication terminal may send information indicating a maximum number of TIDs that the wireless communication terminal can simultaneously receive during the link establishment procedure. At this time, the wireless communication terminal may transmit TID maximum number information using HE capability information element indicating the capability of the terminal. This is because as the number of TIDs of an a-MPDU having a plurality of TIDs increases, a high processing capability of a wireless communication terminal receiving the a-MPDU may be required. The TID maximum number information may be a maximum number of TID fields of the HE capability information element. The maximum number of TID information transmitted by the AP to the non-AP wireless communication terminal may indicate a maximum number of TIDs that MPDUs included in an Uplink (UL) a-MPDU transmitted by the corresponding non-AP wireless communication terminal can have. In addition, the maximum number of TID information transmitted by the non-AP wireless communication terminal to the AP may indicate the maximum number of TIDs that a Downlink (DL) a-MPDU transmitted by the corresponding AP can have. During link setup, the wireless communication terminal may send information of the maximum number of TIDs using the management frame. At this time, the management frame may be at least one of a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, an association response frame, and a beacon frame. Further, when the AP transmits information of the maximum number of TIDs using the beacon frame, the information of the maximum number of TIDs may indicate the number of TIDs that the AP can simultaneously receive. Specifically, when the AP transmits information of the maximum number of TIDs using the beacon frame, the TID maximum number information may indicate the maximum number of TIDs that are allowed to be transmitted in MU UL transmission, instead of the maximum number of TIDs that an MPDU included in an a-MPDU transmitted from any one wireless communication terminal to the AP can have. This is because the AP transmits the beacon frame to the entire wireless communication terminal of the BSS operated by the AP. In another particular embodiment, the maximum amount of TID information for a beacon frame may be used for other purposes. In another particular embodiment, the maximum number of TID fields of a beacon frame may be a reserved field.

In the link establishment procedure, the wireless communication terminal may receive all ACKs from the recipient and transmit an all ACK capability indicator indicating whether the wireless communication terminal can process all ACKs. At this time, the all ACK is an ACK indicating that the receiver receives an a-MPDU transmitted by one initiator or all MPDUs included in the multi-TID a-MPDU. If all ACKs are sent, the initiator may not know information about the fragments sent from all ACKs. In order to process all ACKs, the initiator must store information about the fragments that the initiator sends. This is because the initiator may not be able to store information of the fragments sent by the initiator according to the capabilities. Specifically, the wireless communication terminal may transmit a full ACK capability indicator indicating whether the wireless communication terminal can process full ACKs by using the HE capability information element. A multi TID a-MPDU will be described with reference to fig. 16.

The wireless communication terminal may fragment and transmit at least one of a MAC Service Data Unit (MSDU), an aggregate (a) -MSDU, and a management protocol data unit (MMPDU). For convenience of explanation, a portion of an MSDU, a portion of an a-MSDU, or a portion of an MMPDU generated by fragmentation is referred to as a fragment. In addition, a wireless communication terminal that transmits data is referred to as an initiator, and a wireless communication terminal that receives data is referred to as a recipient.

In particular, the wireless communication terminal may generate a plurality of fragments by fragmenting at least one of the MSDU, A-MSDU, and MMPDU. At this time, the wireless communication terminal may transmit the generated plurality of fragments by using the plurality of MPDUs. In addition, the wireless communication terminal receiving the plurality of fragments may de-fragment the plurality of fragments to obtain at least one of one MSDU, one A-MSDU, and one MMPDU. At this time, the MPDU may be an S-MPDU or an A-MPDU.

The receiver needs sufficient buffering capacity and processing power to defragment the multiple fragments. In particular, the receiver must store all fragments until the receiver receives all fragments corresponding to MSDUs of the same sequence number. Thus, when the recipient supports the ability to receive fragments, the initiator may send the fragments to the recipient. Eventually, the initiator needs to know the segmentation level supported by the receiver. The wireless communication terminal may signal at the segment level. Specifically, the wireless communication terminal transmits information on a segment level of a segment that the wireless communication terminal can receive in a link establishment procedure with the AP, and receives information on a segment level of a segment that the AP can receive. Specifically, the wireless communication terminal may transmit information on the segmentation level using the HE capability information element. At this time, the HE capability information element may indicate the capability of the wireless communication terminal. Further, the wireless communication terminal may transmit information on the segmentation level using at least one of a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, and an association response frame.

As described above, the HE capability information element may include a TID maximum number field, a full ACK capability indicator, and information indicating a fragmentation level supported by the wireless communication terminal (fragmentation support level). The specific format of the HE capability information element may be the same as that of the embodiment of fig. 15.

Further, the wireless communication terminal may set a block ack (addba) parameter in the addition of the BA. At this time, the BA parameters are parameters for BA frame transmission and BA frame reception. The wireless communication terminal may request an ACK in the form of a BA frame using an ADDBA request frame. Further, the wireless communication terminal may transmit a response to the ADDBA request frame using the ADDBA response frame. The ADDBA request frame and ADDBA response frame may include a block Ack parameter set element. At this time, the block Ack parameter set element includes information on the BA parameter. In addition, the wireless communication terminal may set a BA parameter for each TID. In particular, the wireless communication terminal may negotiate BA parameter settings for each TID. In particular embodiments, the wireless communication terminal may use the TID field included in the block Ack parameter set element to specify the TID as the subject of the BA parameter setting negotiation. The originator may request BA parameter settings by sending an ADDBA request frame. The recipient may receive the ADDBA request frame and send an ADDBA response frame for the ADDBA request frame to determine BA parameter settings. When the originator receives the ADDBA response frame and sends an ACK frame for the ADDBA response frame, the originator and the recipient may set the BA parameters.

The wireless communication terminal may transmit buffer size information indicating the number of MPDUs that the wireless communication terminal can store after receiving data in the ADDBA procedure until transmitting a BA frame. In particular, the wireless communication terminal may use the block Ack parameter set element to send buffer size information in the ADDBA procedure. The wireless communication terminal may set the length of the BA bitmap based on the range of values that the buffer size information can have. Specifically, when the range value of the buffer size information can have between 1 and X, the wireless communication terminal may set the length of the BA bitmap to X bits. At this time, when the wireless communication terminal fails to receive information on 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 format of the embodiment of fig. 15.

When the AP performs DL transmission to the wireless communication terminal, the AP may transmit an a-MPDU based on the capability of the wireless communication terminal signaled during link setup and BA parameters set during ADDBA. At this time, the wireless communication terminal may transmit a BA frame or a multi-STA block ACK (M-BA) frame to the AP based on the capabilities of the AP and BA parameters set in the ADDBA procedure. A specific format of the BA frame will be described with reference to fig. 18.

When an AP receives a-MPDUs from a plurality of wireless communication terminals at the same time, it may be difficult to store the plurality of MPDUs received by the AP in a buffer and maintain a scoreboard. At this time, the scoreboard indicates information on the reception status of each MPDU recorded by the AP. Thus, the AP may use the trigger frame to indicate the maximum number of TIDs that each wireless communication terminal can let a-MPDU transmit. In particular, the AP may use the user information field of the trigger frame to indicate the maximum TID to be transmitted by each wireless communication terminal. At this time, the wireless communication terminal receiving the trigger frame may set the number of TIDs that the a-MPDU can have based on the trigger frame. Specifically, the wireless communication terminal receiving the trigger frame may set the number of TIDs of MPDUs included in the a-MPDU based on the maximum number of TIDs indicated by the trigger frame and transmit the a-MPDU to the AP. For example, a wireless communication terminal receiving a trigger frame may set the number of TIDs of MPDUs included in an a-MPDU to be transmitted, which does not exceed the maximum number of TIDs indicated by the trigger frame, and transmit the a-MPDU to an AP.

In addition, when the wireless communication terminal uses the HE MU PPDU in Single User (SU) Uplink (UL) transmission, the wireless communication terminal may be restricted from transmitting a-MPDUs having multiple TIDs. The wireless communication terminal may use the HE MU PPDU in SU UL transmissions using a relatively wide transmission range in a narrow frequency band. At this time, when 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. Thus, when the wireless communication terminal uses the HE MU PPDU in SU UL transmission, the wireless communication terminal may be restricted from transmitting a-MPDUs having multiple TIDs.

The wireless communication terminal may transmit the multi-TID a-MPDU when the wireless communication terminal transmits the HE trigger-based PPDU or transmits the HE MU PPDU in a DL MU transmission. Further, even in SU transmission, the wireless communication terminal can transmit a multi-TID a-MPDU according to a predetermined condition. In particular, the wireless communication terminal may transmit the multi-TID a-MPDU using the HE MU PPDU. Further, the wireless communication terminal may set the number of TIDs of the multi-TID a-MPDU based on the maximum number of TID information described above. In particular, the wireless communication terminal may set the number of TIDs of the multi-TID a-MPDU within the TID maximum number indicated by the TID maximum number information. In UL transmission, the wireless communication terminal may obtain information of the maximum number of TIDs from the association response frame or the authentication response frame. In addition, in DL transmission, the wireless communication terminal may obtain information of the maximum number of TIDs from an association request frame or an authentication request frame.

In the embodiment of fig. 16(a), the non-AP wireless communication terminal transmits a multi-TID a-MPDU to the AP in a UL SU transmission. At this time, the non-AP wireless communication terminal obtains the HE capability information element from an association response (assoc.resp.) frame. Further, the non-AP wireless communication terminal obtains the maximum number of TID information from the maximum number of TID fields of the HE capability information element. In this case, the maximum number of TID information is 4. Thus, the non-AP wireless communication terminal transmits a multi-TID a-MPDU with 4 or less TIDs to the AP.

In the embodiment of fig. 16(b), the AP transmits a multi-TID a-MPDU in a DL SU transmission to a non-AP wireless communication terminal. At this time, the AP obtains the HE capability information element from an association request (assoc. req.) frame. Further, the AP obtains the maximum TID number as 4 from the maximum TID number field of the HE capability information element. Thus, the non-AP wireless communication terminal transmits a multi-TID a-MPDU with 4 or less TIDs to the AP.

The wireless communication terminal aggregates MPDUs stored in the EDCA queues to generate an a-MPDU. At this time, the wireless communication terminal may aggregate MPDUs having TIDs corresponding to the master AC and MPDUs having non-master AC TIDs different from the TIDs corresponding to the master AC to generate a-MPDUs based on a maximum length that the a-MPDUs can have in a corresponding transmission opportunity. In particular, the wireless communication terminal may insert into the a-MPDU all MPDUs having TIDs corresponding to the master AC stored in the buffer, and insert MPDUs having non-master AC TIDs within a maximum length that the a-MPDU can have in a transmission opportunity. In particular embodiments, the wireless communication terminal may insert MPDUs having non-master AC TIDs into a-MPDUs based on user priorities corresponding to the TIDs. Also, the master AC may indicate the ACs of the MPDU for which the transmission opportunity is obtained. For example, the wireless communication terminal may aggregate MPDUs having TIDs corresponding to the master AC and MPDUs having non-master AC TIDs corresponding to ACs of greater user priority than the master AC to generate a-MPDUs.

Further, the wireless communication terminal may aggregate MPDUs having TIDs corresponding to the master AC and at least one of management frames and control frames to generate a-MPDUs. Specifically, 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 master AC into the a-MPDU. In another particular embodiment, the wireless communication terminal may insert an MPDU having a TID corresponding to the master AC into the a-MPDU, insert at least one of a management frame and a control frame into the a-MPDU having a priority next to the priority of the MPDU having the TID corresponding to the master AC, and transmit the a-MPDU. In addition, the wireless communication terminal may aggregate MPDUs having TIDs corresponding to the master AC, MPDUs having non-master AC TIDs corresponding to ACs of user priority greater than the user priority of the master AC, and management frames/control frames to generate a-MPDUs. Specifically, the wireless communication terminal may preferentially insert a management frame or a control frame into an a-MPDU, and insert an MPDU having a TID corresponding to the master AC and an MPDU having a non-master AC TID into the a-MPDU. At this time, as described above, the wireless communication terminal may insert all MPDUs having TIDs corresponding to the master AC stored in the buffer into the a-MPDU, and insert MPDUs having non-master AC TIDs within the maximum length that the a-MPDU can have in a transmission opportunity.

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

Fig. 17(a) shows an EDCA procedure of the first station STA1 in the embodiment of fig. 17. In the embodiment of fig. 17, the AC used by the first station STA1 to obtain the transmission opportunity is AC _ VI. Thus, the main AC is AC _ VI. Further, the maximum number of TIDs that an MPDU included in the a-MPDU generated by the first station STA1 can have is 4. In the embodiment of fig. 17(b), the first station STA1 aggregates MPDUs having TIDs corresponding to the master AC VI and management frames/control frames to generate a-MPDUs. Thus, the first station STA1 aggregates MPDUs and MMPDUs having TIDs 2 corresponding to AC _ VI to generate a-MPDUs. In the embodiment of fig. 17(c), the first station STA1 aggregates MPDUs having a TID corresponding to the master AC, MPDUs having a TID corresponding to an AC having a higher user priority than the master AC, and management frames/control frames to generate a-MPDUs. Thus, the first station STA1 aggregates MPDUs having TID 2 corresponding to AC _ VI, MMPDUs, and MPDUs having TID 1 corresponding to AC _ VO to generate a-MPDUs. Also, in the embodiment of fig. 17(d), the first station STA1 preferentially aggregates MPDUs having TIDs corresponding to the master AC and MPDUs having TIDs having relatively small counter values among the TIDs stored in the EDCA queue to generate a-MPDUs. In the embodiment of FIG. 17, the counter value of the TID stored in the EDCA queue is small in the order of AC _ VI, AC _ BE, and AC _ VO. Thus, the first station STA1 aggregates 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 to generate a-MPDUs.

A wireless communication terminal may transmit a block ack (ba) frame indicating whether multiple MPDUs are received. Further, the wireless communication terminal may transmit a multi-STA block ACK (M-BA) frame indicating whether a multi-TID a-MPDU (multi-STA multi-TID a-MPDU, single-STA multi-TID a-MPDU) is received or whether an MPDU corresponding to one TID (multi-STA single TID) is received from each of the plurality of wireless communication terminals. The M-BA frame may include a per AID TID information subfield indicating whether or not per AID and TID reception is performed.

In particular, the M-BA frame may include a BA control field. At this time, 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 MPDUs, indicating whether a BA is received. Further, the BA information field may indicate whether data is received. In particular, the BA information field may include a bitmap indicating whether each of the MPDUs or sequences is received. At this time, the bitmap may be a block ACK bitmap field.

The block ACK bitmap field is a bitmap indicating whether data is received. A legacy wireless communication terminal may transmit one MSDU in up to 16 fragments. Accordingly, the legacy wireless communication terminal can indicate whether fragments included in each of 64 MSDUs are received by using a block ACK bitmap field having a length of 128 bytes. Specifically, the conventional wireless communication terminal allocates a block ACK bitmap field of 1024 bits to each fragment included in the MSDU and sets a bit corresponding to the received fragment to 1. The legacy wireless communication terminal may indicate whether all fragments are received through the block ACK bitmap field. Therefore, the conventional wireless communication terminal sets the fragment number field of the block ACK starting sequence control field as a reserved field and can use only the sequence number field.

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

The BA information field may include a block ACK starting sequence control subfield that indicates data indicating whether a block ACK bitmap field is received. In particular, the block ACK starting sequence control subfield may indicate a starting number of data indicated by the block ACK bitmap field. The wireless communication terminal may indicate whether bits of the block ACK bitmap field are divided into sequence units or fragment units through the block ACK starting sequence control subfield. In particular, the wireless communication terminal may set the Least Significant Bit (LSB) of the fragment number subfield of the block ACK starting sequence control subfield to 0 to indicate that the bits of the block ACK bitmap field are divided in sequence units. In addition, the wireless communication terminal may set the LSB of the fragment number subfield of the block ACK starting sequence control subfield to 1 to indicate that the bit of the block ACK bitmap field is divided in fragment units. Further, the wireless communication terminal may indicate the length of the block ACK bitmap field through the block ACK starting sequence control subfield. Specifically, the wireless communication terminal may set a value of two bits (LSB +1, LSB +2) of the LSB of the fragment number subfield immediately following the block ACK starting sequence control subfield to indicate the length of the block ACK bitmap field. At this time, the number of BA information fields included in the M-BA frame may be changed according to the number of wireless communication terminals transmitting data and the number of TIDs. In particular, the M-BA frame may include a BA information field where the number of TIDs TID sent by the plurality of wireless communication terminals is repeated.

As described above, the wireless communication terminal may signal the segmentation level supported by the wireless communication terminal during link establishment. In addition, the wireless communication terminal may negotiate the segmentation level in an ADDBA procedure. At this time, if the segmentation level is supported: a level 3 receiver does not receive any MPDUs included in the a-MPDUs, it is difficult for the receiver to determine at which fragmentation level the originator transmits the a-MPDUs. Thus, a segmentation level is supported: a receiver of level 3 may transmit an M-BA frame including a BA bitmap field divided into fragments regardless of the configuration of the received a-MPDU.

Fig. 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 fragments fragmented at fragmentation level 2.

When it is determined that the fragmentation level is 2 or more through the above fragmentation level negotiation, the initiator may transmit an a-MPDU having fragments of fragmentation level 2. At this time, the receiver may transmit a BA frame including a bitmap indicating whether a track sequence unit is received. At this time, the BA frame may be a multi-STA BA frame. The bitmap indicating whether a sequence unit is received does not include information identifying individual clips such as clip numbers. For example, in the embodiment of fig. 19(a), the initiator 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 a plurality of fragments corresponding to sequence numbers 10 to 15. At this time, the bitmap included in the multi-STA BA frame indicates whether all fragments corresponding to the sequence numbers are received, but does not indicate which fragment among the fragments corresponding to the corresponding sequence numbers is received. Specifically, the initiator sends only some fragments of the MSDU corresponding to sequence number 15, but the bitmap included in the multi-STA BA frame does not indicate the fragment number of the corresponding fragment.

Therefore, in order for the initiator to process a bitmap indicating whether a sequence unit is received, the initiator needs to store information identifying a segment or a sequence transmitted by the initiator. Therefore, depending on the function of the initiator, the initiator may not be able to process a bitmap indicating whether a sequence unit is received. For example, the initiator may have to delete or retransmit stored segments depending on whether the recipient received the respective segments. In particular, the initiator may have to retransmit fragments of the same size as the previously transmitted fragments. To do this, the initiator needs to keep track of the size of the fragments sent by the initiator. When the initiator uses static segmentation, the initiator can track the size of the segment without difficulty. In static segmentation, this is because the segments of the same sequence have the same size except for the last segment. However, if the initiator uses dynamic segmentation, the initiator may need to store the sum of the segment sizes sent for each sequence. In dynamic segmentation, this is because even segments of the same sequence may have different sizes. In addition, the wireless communication terminal may not signal whether the wireless communication terminal can process a bitmap indicating whether a sequence unit is received, using information indicating a segment level supported by the wireless communication terminal. Whether or not a bitmap indicating whether or not a sequence unit is received can be processed is independent of whether or not the fragment can be received.

Accordingly, the wireless communication terminal may receive a BA frame including a bitmap indicating whether a sequence unit is received from an originator to signal whether a bitmap indicating whether the sequence unit is received can be processed. For convenience of explanation, information indicating whether it is possible to process a bitmap indicating whether a sequence unit is received is referred to as a sequence unit ACK capability indicator. The wireless communication terminal may signal the sequence unit ACK capability indicator using a management frame during link establishment. At this time, the management frame may be at least one of a probe request frame, a probe response frame, an authentication request frame, an authentication response frame, an association request frame, an association response frame, and a beacon frame.

In a particular embodiment, the wireless communication terminal may signal that the wireless communication terminal can process a bitmap indicating whether sequence units are received by setting the above-described indicator having all ACK capabilities to 1. At this time, the HE capability information element may include the entire ACK capability indicator as in the embodiment of fig. 19 (b). As in the embodiment of fig. 19(c), when the total ACK capability indicator is 0, although the receiver receives an a-MPDU having a fragment level 2 fragment, it cannot transmit a BA frame including a bitmap indicating whether a sequence unit is received.

The processing power required by the receiver to process all ACKs and the power required by the receiver to process a bitmap indicating whether sequence units are received may be different. Specifically, when the receiver can process all ACKs, although the receiver can process a bitmap indicating whether a sequence unit is received, in the case where the receiver can process a bitmap indicating whether a sequence unit is received, the receiver may not be able to process all ACKs. Accordingly, the wireless communication terminal can signal the sequence-unit ACK capability indicator separately from the entire ACK capability indicators. At this time, the HE capability information element may include a sequence unit ACK capability indicator (capable of segmentation level 2 ACK) as in the embodiment of fig. 20 (a).

In the embodiment of fig. 20(b), the entire ACK indicator transmitted by the initiator is 0, and the sequence unit ACK capability indicator is also 0. In this case, the receiver may transmit a BA frame including a bitmap indicating whether a fragment unit is received. In addition, in the embodiment of fig. 20(c), all ACK indicators transmitted by the initiator are 0, and the sequence unit ACK capability 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), all ACK indicators transmitted by the initiator are 1, and the sequence unit ACK capability indicator is also 1. In this case, the receiver may send all ACKs.

The initiator 2101 inserts a plurality of MPDUs into the a-MPDU (S2101). In particular, the initiator 2101 may generate fragments by fragmenting MSDUs, A-MSDUs, or MMPDUs. At this point, the initiator 2101 may use the dynamic segmentation described above.

The initiator 2101 transmits an a-MPDU including a plurality of MPDUs to the receiver 2103 (S2103). Specifically, the initiator 2101 may transmit an A-MPDU comprising the fragment to the receiver 2103. The initiator 2101 may select one of a plurality of fragmentation levels and generate an a-MPDU comprising fragments according to the selected fragmentation level. In this case, the initiator 2101 may select the segmentation level according to the embodiments used for the segmentation level negotiation procedure described above.

Further, the initiator 2101 may send multi-TID a-MPDUs. At this point, the initiator 2101 aggregates MPDUs having TIDs corresponding to the master AC and MPDUs having non-master AC TIDs different from the TIDs corresponding to the master AC to generate a-MPDUs based on the maximum length that the a-MPDUs can have in the corresponding transmission opportunity. Specifically, the initiator 2101 may insert all MPDUs with TIDs corresponding to the master AC stored in the cache into a-MPDUs and insert MPDUs with non-master AC TIDs within the maximum length that a-MPDUs can have in a transmission opportunity. In particular embodiments, the initiator 2101 may insert MPDUs with non-master AC TIDs into a-MPDUs based on user priorities corresponding to the TIDs. At this time, the user priority may be determined according to an Access Category (AC). The master AC may indicate the ACs for the MPDU for which the transmission opportunity is obtained. For example, the initiator 2101 may aggregate MPDUs having TIDs corresponding to the master AC and MPDUs having non-master AC TIDs corresponding to ACs of higher user priority than the master AC to generate a-MPDUs. Further, the initiator 2101 aggregates MPDUs having TIDs corresponding to the master AC and at least one of management frames and control frames to generate a-MPDUs. Specifically, the initiator 2101 inserts at least one of a management frame and a control frame into an a-MPDU, and inserts an MPDU having a TID corresponding to the master AC into the a-MPDU. Specifically, the initiator 2101 may insert at least one of a management frame and a control frame into an a-MPDU regardless of the number of MPDUs having a TID corresponding to the master AC stored in the buffer. In another particular embodiment, the initiator 2101 inserts an MPDU having a TID corresponding to the master AC into an a-MPDU having a priority next to the priority of an MPDU having a TID corresponding to the master AC and transmits the a-MPDU. In addition, the initiator 2101 may aggregate MPDUs having TIDs corresponding to the master AC and MPDUs having non-master AC TIDs corresponding to ACs of higher user priority than the master AC, and manage frames/control frames to generate a-MPDUs. Specifically, the initiator 2101 may prioritize the insertion of management or control frames into a-MPDUs and insertion of MPDUs with TIDs corresponding to the master AC and MPDUs with non-master AC TIDs into a-MPDUs. At this point, as described above, the initiator 2101 may insert all MPDUs with TIDs corresponding to the master AC stored in the buffer into a-MPDUs, and insert MPDUs with non-master AC TIDs within the maximum length that a-MPDUs can have in a transmission opportunity.

Further, the initiator 2101 preferentially aggregates MPDUs having TIDs corresponding to the master AC and MPDUs having non-master AC TIDs whose counter values are relatively low among the TIDs stored in the EDCA queue to generate a-MPDUs. Further, the initiator 2101 may determine the number of TIDs of MPDUs included in the a-MPDU according to the maximum number of TID information in the above-described embodiments. The specific operation of the initiator 2101 may be the same as that of the embodiment described with reference to fig. 17.

The initiator 2101 may manage information about the fragments by each combination of recipient, Traffic Identifier (TID), and sequence number. The initiator 2101 may generate a new segment based on the information about the segment. In particular, the initiator 2101 may determine a segment start point for a new segment based on information related to the segment. In addition, the initiator 2101 may assign a segment number to a new segment based on information related to the segment. In this case, the information on the clip may include information on a start point indicating the start of the segment, and information on a clip number. The specific operation of the initiator 2101 may be the same as that of the embodiment described with reference to fig. 12.

In addition, the initiator 2101 may insert sequence numbers corresponding to the fragments into the fragments, as in the embodiments described with reference to fig. 9 and 10.

In another particular embodiment, the initiator 2101 may store all fragments of a corresponding previously generated MSDU until the last fragment of the MSDU is generated. The initiator 2101 may generate a new fragment based on all fragments of the corresponding previously generated MSDU. In particular, the initiator 2101 may determine a segment start point for a new segment based on all segments of a corresponding previously generated MSDU. In addition, the initiator 2101 may assign fragment numbers to new fragments based on all fragments of the corresponding previously generated MSDU. The specific operation of the initiator 2101 may be the same as that of the embodiment described with reference to fig. 13.

In another particular embodiment, the initiator 2101 may generate all fragments of one MSDU together. Specifically, the initiator 2101 may generate all fragments for any one MSDU in the same transmission opportunity. The specific operation of the initiator 2101 may be the same as that of the embodiment described with reference to fig. 14.

In addition, the initiator 2101 may signal information indicating whether the initiator is capable of handling a particular ACK type. Specifically, the initiator 2101 may send a full ACK capability indicator indicating whether the initiator may process all ACKs.

In this case, the full ACK is an ACK indicating that the receiver receives all MPDUs included in the a-MPDU or a multi-TID a-MPDU transmitted by one initiator. In addition, the initiator 2101 may transmit capability information indicating whether bitmaps that the initiator can process data are received in units of a sequence. The energy information indicating whether the bitmap of data in sequence units can be processed may be the sequence unit ACK capability indicator described above. The initiator 2101 may send an ACK capability indicator. Also, as described with reference to fig. 19, the initiator 2101 may use the full ACK capability indicator to signal the capability to indicate whether a bitmap indicating whether data was received in sequence units can be processed.

The receiver 2103 receives an a-MPDU including a plurality of MPDUs from the initiator 2101. In particular, the receiver 2103 may receive an A-MPDU comprising a fragment from the initiator 2101. The receiver 2103 transmits a BA frame to the initiator 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 information indicating whether the specific ACK type can be processed. Specifically, the recipient 2103 may determine whether to send a BA frame to the recipient indicating all ACKs based on the all ACK capability indicator. Further, the recipient 2103 may determine whether to send a BA frame to the recipient including a bitmap indicating whether to perform reception in sequence units based on the ACK capability indicator.

Although the present invention is described by using wireless LAN communication as an example, the present invention is not limited thereto and may be applied to other communication systems such as cellular communication. Additionally, although the method, apparatus and system of the present invention have been described in connection with particular embodiments thereof, some or all of the components or operations of the present invention may be implemented using a computer system having a general-purpose hardware architecture.

The features, structures, and effects described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, those skilled in the art may combine or modify the features, structures, and effects shown in each embodiment in other embodiments. Therefore, it should be understood that matters relating to such combination and modification are included within the scope of the present invention.

Although the present invention has been described mainly based on the above embodiments, but is not limited thereto, those skilled in the art will appreciate that various changes and modifications may be made without departing from the spirit and scope of the invention. For example, each component specifically shown in the embodiments may be modified and implemented. It is to be understood that differences relating to such modifications and applications are included within the scope of the present invention as defined in the appended claims.

Claims

1. A wireless communication terminal for wireless communication, the terminal comprising:

a transceiver; and

a processor for processing the received data, wherein the processor is used for processing the received data,

wherein the processor is configured to insert MAC Protocol Data Units (MPDUs) having a Traffic Identifier (TID) corresponding to a primary Access Class (AC) into an aggregate MPDU (A-MPDU),

inserting into the A-MPDU an MPDU having a non-master AC TID that is a different TID than a TID corresponding to the master AC based on a user priority corresponding to the TID corresponding to the master AC and a maximum length the A-MPDU can have in a respective transmission opportunity,

inserting a management frame into the A-MPDU, an

Transmitting the A-MPDU to a recipient using the transceiver.

2. The wireless communication terminal of claim 1, wherein the processor is configured to insert all MPDUs having the TID corresponding to the master AC stored in a buffer into an a-MPDU, and

inserting into the A-MPDUs having the non-master AC TIDs corresponding to ACs having a user priority within the maximum length that is higher than a user priority of the master AC.

3. The wireless communication terminal of claim 1, wherein the processor is configured to insert a control frame into the a-MPDU.

4. A method of operation of a wireless communication terminal for wireless communication, the method comprising:

inserting an MPDU having a Traffic Identifier (TID) corresponding to a master AC into an aggregated MAC protocol data unit (A-MPDU);

inserting into the A-MPDU an MPDU having a non-master Access Category (AC) TID that is a different TID than a TID corresponding to the master AC based on a user priority corresponding to the TID corresponding to the master AC and a maximum length that the A-MPDU can have in a respective transmission opportunity;

inserting a management frame into the A-MPDU; and

and sending the A-MPDU to a receiver.

5. The method of claim 4, wherein inserting the MPDU having the non-master AC TID into the A-MPDU based on the maximum length comprises: inserting into an A-MPDU all MPDUs having the TID corresponding to the master AC stored in a buffer, and inserting into the A-MPDU an MPDU having the non-master AC TID corresponding to an AC having a user priority within the maximum length that is higher than a user priority of the master AC.

6. The method of claim 4, further comprising inserting a control frame into the A-MPDU.