CN114866197B

CN114866197B - Wireless communication method using aggregated MPDU and wireless communication terminal using the same

Info

Publication number: CN114866197B
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: 2024-04-02
Anticipated expiration: 2037-06-14
Also published as: CN109314882A; KR20220034915A; KR102411787B1; CN114900270A; KR20190008537A; KR102567626B1; WO2017217766A1; KR20220031144A; CN114866197A; CN114884628A; KR102371756B1; 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 transmitting/receiving unit.

Description

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

The present application is a divisional application of patent application with the name of "wireless communication method using aggregated MPDUs and wireless communication terminal using the same", filed on 12 months 13 of 2018, and with the application number 201780036770.3 (PCT/KR 2017/006210) of 14 of 6 months 14 of international application date of the chinese patent office.

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 been expanding, wireless communication technologies that can provide rapid wireless internet services to mobile devices have been receiving significant attention. Wireless communication technology allows mobile devices, including smart phones, smartcards, laptops, portable multimedia players, embedded devices, etc., to wirelessly access the internet in a home or company or specific service providing area.

One of the most well-known wireless communication technologies is the 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 11Mbps at maximum when using frequencies of the 2.4GHz band. The IEEE 802.11a commercialized after the IEEE 802.11b uses frequencies not the 2.4GHz band but the 5GHz band, reduces the influence of interference compared to frequencies of significant congestion of the 2.4GHz band, and increases the 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 realizes a communication speed of a maximum 54Mbps using a frequency of a 2.4GHz band and satisfies backward compatibility to be clearly paid attention to the public similarly to IEEE 802.11b, and further is superior to IEEE 802.11a in terms of communication distance.

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

As the supply of wireless LANs is active and applications using wireless LANs further diversify, a 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 paid attention to. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) of 5GHz frequency. The IEEE 802.11ac standard is defined only in the 5GHz band, but the original 11ac chipset would 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 speeds 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 expanding the concepts of wireless interfaces accepted by 802.11n, such as wider wireless frequency bandwidth (max 160 MHz), more MIMO spatial streams (max 8), multi-user MIMO, and high density modulation (max 256 QAM). In addition, as a scheme for transmitting data by using a 60GHz band instead of the existing 2.4GHz/5GHz, IEEE 802.11ad has been provided. IEEE 802.11ad is a transmission standard that provides a maximum speed of 7Gbps by using a beamforming technique and is suitable for high bit rate moving image streams 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 in a short distance space.

Meanwhile, in recent years, as a next-generation wireless communication technology standard after 802.11ac and 802.11ad, discussion on providing high-efficiency and high-performance wireless communication technology in a high-density environment is continuously underway. 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 a high-density terminal and a base terminal, 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, a technique capable of efficiently using bandwidth by simultaneously transmitting data between a plurality of terminals and a base terminal is required.

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 proposal

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 aggregate MAC protocol data unit (a-MPDU) comprising the fragments to the receiver using the transceiver.

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

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

The processor may be configured to: all fragments of the corresponding previously generated MSDU are stored until the 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 can process a bitmap indicating whether data is received in sequence units is transmitted by using a 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 a MAC Protocol Data Unit (MPDU) having a TID corresponding to a primary Access Category (AC) into an aggregate MPUD (a-MPDU), insert a MPDU having a non-primary AC TID that is a TID different from the TID corresponding to the primary AC into the a-MPDU based on a user priority corresponding to the TID, and transmit the a-MPDU to a receiver by using the transceiver.

The processor may be configured to insert MPDUs with non-master AC TIDs into the a-MPDUs based on the maximum number of TIDs the a-MPDUs can have.

The processor may be configured to insert MPDUs with non-primary AC TIDs into the a-MPDUs based on a maximum length the a-MPDUs can have in a respective transmission opportunity.

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

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, a method of operating a wireless communication terminal for wireless communication includes: generating fragments by dividing MAC Protocol Data Units (MPDUs), aggregate MAC service data units (a-MSDUs), or management protocol data units (MMPDUs); and transmitting the a-MPDU including the fragment to the receiver.

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

The information about the segment may include information about a start point of a point indicating the start of the segment and information about a segment number.

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

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

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

According to an embodiment of the present invention, a method of operating a wireless communication terminal of a wireless communication terminal includes: inserting MPDUs having TIDs corresponding to the primary ACs into an aggregate MAC protocol data unit (a-MPDU); inserting MPDUs having a non-primary Access Category (AC) TID as a TID different from the TID corresponding to the primary ACI in the a-MPDU based on the user priority corresponding to the TID; and transmitting the a-MPDU to the receiver.

Inserting MPDUs with non-master AC TIDs into a-MPDUs may include: MPDUs with non-primary AC TIDs are inserted into the a-MPDUs based on the maximum length the a-MPDUs 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 illustrates a wireless LAN system according to an embodiment of the present invention.

Fig. 2 illustrates 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 present invention.

Fig. 5 illustrates a process 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 aggregating MAC protocol data units (a-MPDUs) according to an embodiment of the present invention.

Fig. 7 illustrates a wireless communication terminal transmitting an a-MPDU with 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 a wireless communication terminal assigning sequence numbers to MSDUs 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 segment numbers to segments in a wireless communication terminal dynamic segmentation operation according to an embodiment of the present invention.

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

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

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

Fig. 15 illustrates a method for transmitting a Block ACK (BA) frame for aggregating MAC protocol data units (a-MPDUs) according to an embodiment of the present invention.

Fig. 16 illustrates a wireless communication terminal transmitting an a-MPDU with 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 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 a wireless communication terminal transmitting an ACK for an a-MPDU including a fragment segmented at a segmentation level 2 according to an embodiment of the present invention.

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. Portions not related 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.

Furthermore, when an item is described as comprising (or containing or having) some elements, it should be understood that it may comprise (or contain or have) only those elements, or it may comprise (or contain or have) other elements as well as those elements, if not specifically limited.

The present application claims priority and benefits of korean patent application nos. 10-2016-0074190 (2016.06.14), 10-2016-0093811 (2016.07.23), and 10-2016-0104407 (2016.08.17) filed in the korean intellectual property office, and the embodiments and the mentioned items described in the corresponding 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 into an infrastructure BSS and an Independent BSS (IBSS) and fig. 1 illustrates the infrastructure BSS therebetween.

As illustrated in fig. 1, the infrastructure BSS (BSS 1 and BSS 2) includes 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) and a physical layer interface for a wireless medium following a procedure of the IEEE 802.11 standard, 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 wireless LAN communication devices such as non-AP STAs or APs or both. A station for wireless communication comprises a processor and a transceiver and may further comprise a user interface unit and a display unit according to this embodiment. The processor may generate a frame to be transmitted through the 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 to the processor and transmits and receives frames over a wireless network for the station.

An Access Point (AP) is an entity that provides access to an Distribution System (DS) for stations associated therewith via a wireless medium. In the infrastructure BSS, communication between non-AP stations is performed in principle via an AP, but when a direct link is configured, direct communication is enabled 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 including a centralized controller, a Base Station (BS), a node B, a Base Transceiver System (BTS), and a site controller in a broad sense.

The plurality of infrastructure BSSs may be connected to each other through a Distribution System (DS). In this case, the BSSs connected through the distribution system are called Extended Service Sets (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 repetitive description of the same or corresponding portions to the embodiment of fig. 1 will be omitted.

Because BSS3 illustrated in fig. 2 is an independent BSS and does not include an AP, all stations STA6 and STA7 are not connected to the AP. The independent BSS is not admitted to the distribution system and forms a complete network. In an 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 the 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 or the like and may be embedded in the station 100 or set to be external. According to this embodiment, the transceiver 120 may include at least one transmitting and receiving module using different frequency bands. For example, transceiver 120 may include transmit and receive modules having different frequency bands such as 2.4GHz, 5GHz, and 60 GHz. According to an embodiment, the station 100 may include a transmitting and receiving module using a frequency band of 6GHz or higher and a transmitting and receiving 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 together simultaneously, 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 inputs by using various input devices and the processor 110 may control the station 100 based on the received user inputs. 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 content or a user interface executed by the processor 110, based on control commands of the processor 110, etc. In addition, the memory 160 stores control programs used in the station 100 and various resultant data. The control procedure may include an access procedure required for the station 100 to access the AP or an external station.

The processor 110 of the present invention may 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 an 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 a certain component (e.g., transceiver 120, etc.) of the station 100. 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 according to an embodiment of the invention, in which individual blocks are illustrated as logically distinct elements of a device. Thus, elements of the device may be mounted in a single chip or 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 an 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 described in the embodiment of fig. 3, the transceiver 220 of the AP 200 may also include a plurality of transmitting and receiving modules using different frequency bands. That is, the AP 200 according to an embodiment of the present invention may include two or more transmitting and receiving modules among different frequency bands (e.g., 2.4GHz, 5GHz, and 60 GHz) together. Preferably, the AP 200 may include a transmitting and receiving module using a 6GHz or higher frequency band and a transmitting and receiving module using a 6GHz or lower frequency band. The respective transmitting and receiving modules may perform wireless communication with the station according to a wireless LAN standard of a frequency band supported by the corresponding transmitting and receiving modules. Transceiver 220 may operate only one transmit and receive module at a time or multiple transmit and receive modules together simultaneously, 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 procedure may comprise an access procedure for managing access by 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 present invention, the processor 210 may execute a program for accessing stations stored in the memory 260 and transmit a communication configuration message for one or more stations. In this case, the communication configuration message may include information on access priority conditions of the corresponding station. In addition, the processor 210 performs access configuration according to an access request of the station. The processor 210 may be a modulator and/or demodulator that modulates wireless signals transmitted to the transceiver 220 and demodulates wireless signals received from the 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 procedure in which a STA sets up a link with an AP.

Referring to fig. 5, the 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 periodically transmitted beacon message (S101) and an active scanning method in which the STA 100 transmits a probe request to the AP (S103) and obtains access information by receiving a probe response from the AP (S105).

The STA 100 that successfully received the wireless access information in the scanning step performs the authentication step by transmitting an authentication request (S107 a) 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 (S109 a) and receiving an association response from the AP 200 (S109 b).

Meanwhile, an authentication step based on 802.1X (S111) and an IP address obtaining step through DHCP (S113) 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 a particular embodiment, the AP 200 may be a wireless communication terminal that allocates communication media resources and performs scheduling in a separate 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. TP 200 may also be referred to as a base communication terminal.

A 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. In particular, 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, the wireless communication terminal receiving the data may receive the PPDU and obtain MPDUs from the PPDU. Through 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 receiver. Specific operations of the initiator and the receiver will be described with reference to fig. 6 to x.

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

In the MAC layer, the wireless communication terminal receives a MAC Service Data Unit (MSDU) from 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 may obtain a transmission opportunity through a contention process. In particular, the wireless communication terminal may start a contention procedure for channel access when the wireless medium is idle. In addition, the wireless communication terminal may obtain channel access rights 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. In particular, the wireless communication terminal may transfer the MAC du from the MAC layer to the physical layer. The wireless communication terminal may generate a PPDU by adding a physical layer header to an 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 the MSDU every time a new MSDU is transmitted. Specifically, each time the wireless communication terminal transmits a new MSDU, the wireless communication terminal may assign a sequence number one greater than the previously assigned sequence number to the MSDU. 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 MPDUs in the MAC layer and determine sequence numbers to be allocated to MSDUs using SNS. Thus, the wireless communication terminal can manage MSDUs having the same RA and the same TID in one sequence number space. Through this operation, the wireless communication terminal can efficiently manage the sequence numbers allocated to the MSDUs.

Further, the wireless communication terminal manages transmission and retransmission by MPDU unit. Accordingly, the wireless communication terminal stores the MPDU until an ACK for the MPDU is received. Specifically, the wireless communication terminal buffers MPDUs until receiving ACKs for the MPDUs. When the wireless communication terminal receives an 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, information indicating that the ACK and the receiver have not received the MPDU may be received through at least one of an ACK frame, a Block ACK (BA) frame, and a multi-STA BA frame. Further, the wireless communication terminal stores the MSDU in a buffer. The wireless communication terminal deletes the MSDU successfully transmitted to the receiver from the buffer.

In the embodiment of fig. 5, the first station STA1 transmits an MSDU with TID 2 to the receiver with RA 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 a receiver with RA of 3, respectively. The first station STA1 generates an aggregated MPDU (a-MPDU) including three MSDUs. The first station STA1 transmits the generated a-MPDU using the PPDU. The first station STA1 receives a BA frame comprising 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 probability of transmission failure may increase. In particular, the wireless communication terminal may segment and transmit at least one of an MSDU, an aggregate (a) -MSDU, and a management protocol data unit (MMPDU). For ease 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 segment at least one of the MSDU, the A-MSDU, and the MMPDU to generate the 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, a wireless communication terminal receiving the plurality of fragments may defragment the plurality of fragments to obtain at least one of an MSDU, an A-MSDU, and an MMPDU. At this time, the MPDU may be an S-MPDU or an A-MPDU. The wireless communication terminal may generate fragments other than the last fragment in a fixed size. In addition, the wireless communication terminal may generate fragments that are not of a fixed size. Segments with a fixed segment size other than the last segment are called 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 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 fragment number to each combination of the same RA, TID, and sequence number. In particular embodiments, the wireless communication terminal may assign a fragment number that is increased by 1 to each fragment generated from the same MSDU. In this case, the wireless communication terminal may assign a segment number starting from 0 to the segment. Further, the wireless communication terminal may generate fragments at the beginning of the transmission sequence of the MSDUs. The wireless communication terminal stores the fragments after transmitting the fragments using the MPDU. In particular, the wireless communication terminal may buffer the fragments after transmitting the fragments using MPDUs. Through this operation, the wireless communication terminal can distinguish the segments and effectively manage the segments.

The wireless communication terminal may continuously transmit each of the 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 fragment burst transmission, when the wireless communication terminal receives an ACK for a previously transmitted MPDU, the wireless communication terminal may transmit a 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 segment burst transmission, the wireless communication terminal may generate one segment at a time. Specifically, fragments may be generated upon receipt of an ACK for a previously transmitted MPDU. In the present embodiment, the wireless communication terminal transmits only MPDUs including one fragment at a time, and may not transmit a-MPDUs transmitting a plurality of MPDUs. When the wireless communication terminal fails to receive an ACK for the previously transmitted MPDU in the 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 process, and retransmits the MPDU including the previously transmitted fragment. Specifically, the wireless communication terminal may retransmit MPDUs including the stored fragments. At this point, the stored fragments may indicate cached fragments as described above.

In the fragment burst transmission, the wireless communication terminal generates a new fragment upon receiving an ACK of the previously transmitted MPDU as described above. At this time, the wireless communication terminal assigns a segment number to the new segment based on the stored segment. Specifically, the wireless communication terminal may assign a number larger than that of the stored fragment to the fragment number of the new fragment. 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. Further, 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 this embodiment, the wireless communication terminal may generate a new segment using only the stored segment and assign a segment number. Therefore, the wireless communication terminal may not use the tracking space for tracking the segment number assignment and the segment start point tracking space.

In the embodiment of fig. 7, the first station STA1 fragments one MSDU into four fragments and transmits the fragments. The first station STA1 allocates 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. Further, the first station STA1 assigns the segment number of the second segment 31.1 to 1 because the segment number of the buffered segment is zero. The first station STA1 transmits an MPDU comprising the second fragment 31.1 and the first station STA1 receives an ACK frame for the MPDU comprising 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 allocates the fragment number of the third fragment 31.2 to 2, because the fragment number of the buffered 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.

Accordingly, the first station STA1 returns a transmission opportunity and obtains a new transmission opportunity through the contention process. The first station again transmits MPDUs comprising the third buffer fragment 31.2. The first station STA1 receives the 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 segment number of the third segment 31.3 to 3 because the segment number of the buffered segment 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 can generate fragments that are not of a fixed size. Further, the wireless communication terminal may transmit an MPDU including a fragment together with another MPDU. In particular, the wireless communication terminal may transmit an a-MPDU including an MPDU having a fragment of another MPDU.

Further, when dynamic fragmentation is used, the initiator generates fragments according to the fragmentation level and transmits MPDUs including the fragments. At this point, the initiator may determine the segmentation level based on the capabilities of the recipient. At this time, the segment level indicates the degree of the segment 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 MPDUs including one fragment. At this point, 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 including one fragment per MSDU. In particular, level 2 may indicate that the wireless communication terminal is capable of receiving a-MPDUs comprising one or fewer fragments per MSDU. Level 3 may indicate that the wireless communication terminal is capable of receiving a-MPDUs comprising a plurality of fragments per MSDU. 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 can signal information about the segmentation level during the link setup process. In addition, the initiator and the recipient may negotiate information about the segmentation level during the ADDBA procedure. This will be described in detail with reference to fig. 15 to 20.

In the embodiment of fig. 8, the recipient supports segment level 3. In the embodiment of fig. 8, the initiator fragments the MSDU at fragment level 2. Thus, the initiator transmits 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 the MSDU corresponding to sequence number 6, a first fragment 7.0 of the MSDU corresponding to sequence number 7, a first fragment 8.0 of the MSDU corresponding to sequence number 8, a first fragment 9.0 of the MSDU corresponding to sequence number 9, and a first fragment 10.0 of the MSDU corresponding to sequence number 10. In the embodiment of fig. 8, the initiator fragments the MSDU at fragment level 3. Thus, the initiator transmits an a-MPDU 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. Specifically, each time the wireless communication terminal transmits a new MSDU, the wireless communication terminal may assign a sequence number one greater than the previously assigned sequence number to the MSDU. When the initiator uses static fragmentation, the initiator sends one fragment at a time, sends all fragments of one MSDU, and then sends new fragments. 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, the first station STA1 transmits an a-MPDU comprising an MSDU 6.0 corresponding to sequence number 6, an MSDU 7.0 corresponding to sequence number 7, and a first fragment 8.0 of the MSDU corresponding to sequence number 8 to at least one receiver. The first station STA1 receives a BA frame from at least one recipient indicating that the MSDU 6.0 corresponding to sequence number 6, the MSDU 7.0 corresponding to sequence number 7, and the first fragment 8.0 of the MSDU corresponding to sequence number 8 are received.

The first station STA1 transmits an a-MPDU comprising a second fragment 8.1 of an MSDU corresponding to sequence number 8 and an MSDU different from 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. Accordingly, the first station STA1 allocates the sequence number 8 to MSDUs other than the MSDU corresponding to the sequence number 8. The receiver determines whether to repeatedly receive the MSDU 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 repeated MSDUs are received so that it may send an ACK for the MSDU to the initiator and may not forward the MSDU to an upper layer.

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

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

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

When the wireless communication terminal uses static fragmentation, the wireless communication terminal may determine a fragmentation start point of the MSDU based on the last transmitted fragmentation. 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 sizes of the fragments except the last one are fixed. Specifically, if the number of fragments increases from 0 to 1, the wireless communication terminal may 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 cannot determine the start point of fragmentation of the MSDU based on the fragment number of the last transmitted fragment.

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

When the first station STA1 transmits the remaining fragment of the MSDU with TID 1 and sequence number 8 or the remaining fragment of the MSDU with TID 2 and sequence number 32, the first station STA1 may not know the start point 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 the information related to the segments through each combination of the receiver, TID, and sequence number. In addition, the wireless communication terminal may generate a new segment based on the information related to the segment. In particular, 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 fragment number to the new fragment based on the information related to the fragment. At this time, the information related to the segment may be at least one of information about a segment number and information about a segment start point. In particular, when the wireless communication terminal uses dynamic segmentation, the wireless communication terminal can manage information about a segment number and information about a segmentation start point. In particular embodiments, the wireless communication terminal may store the fragment number of the last transmitted fragment. In addition, the wireless communication terminal may store a sum of sizes of previously generated fragments. In addition, the wireless communication terminal may store information about the segment number and information about the segment start point in the form of tuples. In a particular embodiment, the wireless communication terminal may use a segment number space (FNS) for managing information about segment numbers and information about segment start points. Specifically, FNS can be defined as shown in the following table.

TR1: the transmitting STA should buffer the cumulative size of the fragments from the acknowledgement of the assigned fragment number for this fragment number space

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

In the embodiment of fig. 12, the first station STA1 transmits an a-MPDU comprising two MSDUs and fragments with TID of 1 and one MSDU and fragments with TID of 2 to at least one receiver. In this case, the sequence numbers of the two MSDUs 6.0 and 7.0 with TID 1 are 6 and 7, respectively. For one segment 8.0 with a TID of 1, the sequence number is 8 and the segment number is 0. Further, serial number 31 of one MSID 31.0 having TID of 2. For a 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 fragments with TID of 1 and one MSDU and fragments with 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 TID 1 and sequence number 8. Specifically, the first FNS stores the sum of the sizes of the fragments with TID 1 and sequence number 8 that were sent to the first recipient, and the fragment number 0 of the fragment with TID 1 and sequence number 8 that was finally sent to the first recipient. In addition, the second FNS stores information for the second recipient's transmission of fragments having TID of 2 and sequence number 32. Specifically, the second FNS stores the sum of the sizes of the fragments with TID 2 and sequence number 32 that were transmitted to the second recipient, and the fragment number 0 of the fragment with TID 2 and sequence number 32 that was finally transmitted to the second recipient. Accordingly, the first station STA1 determines a segment start point for the segment of the first receiver having TID 1 and sequence number 8 based on the first FNS. Further, the first station STA1 assigns 1 as a fragment number to a fragment having TID of 1 and sequence number of 8 based on the first FNS. Accordingly, the first station STA1 determines a segment start point of a segment having TID of 2 and sequence number of 32 for the second receiver based on the second FNS. Further, the first station STA1 assigns 1 as a segment number to the segment having TID of 2 and sequence number of 32 for the second receiver based on the second FNS.

In another particular embodiment, the wireless communication terminal may store all fragments of the corresponding previously generated MSDU until the last fragment of the MSDU is generated. In particular, the wireless communication terminal may buffer all fragments of the 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 segment. In particular, the wireless communication terminal may determine a segment start point of the new segment based on the stored segment. In addition, the wireless communication terminal may assign a fragment number to the new fragment based on the stored fragment. In particular, the wireless communication terminal may store MPDUs including all fragments of the 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 BA frames only to MSDUs transmitting all fragments to the receiver. This is because the wireless communication terminal can store MPDUs until it receives an ACK from the receiver.

In the embodiment of fig. 13, the first station STA1 transmits an a-MPDU comprising two MSDUs and fragments with TID of 1, and one MSDU and fragments with TID of 2, to at least one receiver. In this case, the sequence numbers of the two MSDUs 6.0 and 7.0 with TID 1 are 6 and 7, respectively. For one segment 8.0 with a TID of 1, the sequence number is 8 and the segment number is 0. Further, serial number 31 of one MSID 31.0 having TID of 2. For one fragment 32.0 with 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 fragments with TID of 1 and one MSDU and fragments with TID of 2.

At this time, since the first station STA1 does not transmit all fragments of the MSDU having TID 1 and sequence number 8 and all fragments of the MSDU having TID 2 and sequence number 32, the first station STA1 buffers the fragments having TID 1 and sequence number 8 and the fragments having TID 2 and sequence number 32. Accordingly, the first station STA1 determines a segment start point of a segment having TID of 1 and sequence number of 8 based on the buffered segment. Further, the first station STA1 allocates 1 as a fragment number to a fragment having TID of 1 and sequence number of 8 based on the buffered fragment. Further, the first station STA1 determines a segment start point of a segment having TID of 2 and sequence number of 32 for the second receiver based on the buffered segment. Further, the first station STA1 allocates 1 as a fragment number to a fragment having TID of 2 and sequence number of 32 based on the buffered fragment. With this embodiment, the wireless communication terminal can efficiently manage information about the 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 transmits an a-MPDU comprising two MSDUs and fragments with TID of 1 and one MSDU and fragments with TID of 2 to at least one receiver. In this case, the sequence numbers of the two MSDUs 6.0 and 7.0 with TID 1 are 6 and 7, respectively. For one segment 8.0 with a TID of 1, the sequence number is 8 and the segment number is 0. In addition, one MSID 31.0 with TID 2 has a serial number of 31. For a 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 fragments with TID of 1 and one MSDU and fragments with TID of 2.

At this time, the first station STA1 generates three fragments of the MSDU having 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. In addition, the first station STA1 generates three fragments of MSDUs having TID of 2 and sequence number of 32 together at one transmission opportunity. However, the first station STA1 transmits only one segment 32.0 as described above, and transmits the remaining two segments 32.1 and 32.2 in the next transmission opportunity. By such an embodiment, the wireless communication terminal can efficiently manage information about the clip without storing additional information or buffering the clip.

The wireless communication terminal may combine multiple MPDUs to generate one a-MPDU. The wireless communication terminal may transmit the generated a-MPDU. Conventional wireless communication terminals combine MPDUs having the same Traffic Identifier (TID) only 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, the wireless communication terminal may transmit an a-MPDU having a plurality of 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 an HE trigger-based PPDU.

The wireless communication terminal may set parameters related to a-MPDU and BA frame transmission during link establishment. The wireless communication terminal may set parameters related to an a-MPDU having a plurality of TIDs during link setup. Specifically, the wireless communication terminal may transmit information indicating the maximum number of TIDs of the maximum number of TIDs that the wireless communication terminal can simultaneously receive in the link establishment procedure. At this time, the wireless communication terminal may transmit information of the maximum number of TIDs using HE capability information elements indicating the capabilities of the terminal. This is because as the number of TIDs of an a-MPDU having a plurality of TIDs increases, high processing power of a wireless communication terminal receiving the a-MPDU may be required. The information of the maximum number of TIDs may be the maximum number of TID fields of the HE capability information element. The maximum number of TID information transmitted by an AP to a non-AP wireless communication terminal may indicate the maximum TID number that MPDUs included in Uplink (UL) a-MPDUs transmitted by the corresponding non-AP wireless communication terminal can have. In addition, the maximum number of TID information transmitted to an AP by a non-AP wireless communication terminal may indicate the maximum number of TIDs that a Downlink (DL) a-MPDU transmitted by a corresponding AP can have. During link establishment, the wireless communication terminal may transmit TID maximum amount of information using a 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 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 a 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 the reserved field.

During the link establishment procedure, the wireless communication terminal may receive all ACKs from the receiver and transmit an all ACK capability indicator indicating whether the wireless communication terminal is capable of handling all ACKs. At this time, all ACKs are ACKs 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 the information about the fragments sent from all ACKs. In order to handle all ACKs, the initiator must store information about the fragments sent by the initiator. This is because the initiator may not be able to store the information of the fragments transmitted by the initiator according to the capability. Specifically, the wireless communication terminal may transmit a full ACK capability indicator indicating whether the wireless communication terminal can process the full ACK 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 segment and transmit at least one of a MAC Service Data Unit (MSDU), an aggregate (a) -MSDU, and a management protocol data unit (MMPDU). For ease 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 called an initiator, and a wireless communication terminal that receives data is called a receiver.

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

The receiver needs sufficient buffer capacity and processing power to de-segment the multiple segments. In particular, the receiver must store all fragments until the receiver receives all fragments of the MSDU corresponding to the same sequence number. Thus, when the recipient supports the ability to receive fragments, the initiator may send 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 the segment level of the segment that the wireless communication terminal can receive in the link establishment procedure with the AP, and receives information on the segment level of the segment that the AP can receive. In particular, the wireless communication terminal may transmit information on the segment 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 about the segment 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 field of the maximum number of TIDs, an all ACK capability indicator, and information indicating a segmentation level supported by the wireless communication terminal (segmentation 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 BA parameter in the addition of the block ACK (ADDBA). At this time, the BA parameters are parameters for BA frame transmission and BA frame reception. The wireless communication terminal may request ACK in the form of BA frame using the 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 the ADDBA response frame may include a block Ack parameter set element. At this time, the block Ack parameter set element includes information about BA parameters. In addition, the wireless communication terminal may set BA parameters for each TID. Specifically, the wireless communication terminal may negotiate BA parameter settings for each TID. In a particular embodiment, the wireless communication terminal may specify TID, which is a subject of BA parameter setting negotiation, using TID field included in the block Ack parameter set element. The initiator 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 the BA parameter settings. The initiator and the recipient may set the BA parameter when the initiator receives the ADDBA response frame and sends an ACK frame for the ADDBA response frame.

The wireless communication terminal may transmit buffer size information indicating the number of MPDUs that the wireless communication terminal can store until a BA frame is transmitted after receiving data in the ADDBA procedure. In particular, the wireless communication terminal may transmit the buffer size information using the block Ack parameter set element in the ADDBA procedure. The wireless communication terminal may set the length of the BA bitmap based on a 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 that 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 in the link setup procedure and the BA parameter set in the ADDBA procedure. 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 each wireless communication terminal is capable of having a-MPDUs transmitted. Specifically, the AP may indicate a maximum TID to be transmitted by each wireless communication terminal using a user information field of the trigger frame. 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 TID maximum number 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 a Single User (SU) Uplink (UL) transmission, the wireless communication terminal may be restricted from transmitting a-MPDUs having a plurality of TIDs. The wireless communication terminal may use the HE MU PPDU in the SU UL transmission using a relatively wide transmission range in a narrow frequency band. At this time, when the 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 contention with other wireless communication terminals. Accordingly, when the wireless communication terminal uses the HE MU PPDU in SU UL transmission, the wireless communication terminal may be restricted from transmitting a-MPDUs having a plurality of TIDs.

The wireless communication terminal may transmit the multi TID a-MPDU when the wireless communication terminal transmits the HE trigger-based PPDU or the HE MU PPDU in the 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 a multi-TID a-MPDU using the HE MU PPDU. Further, the wireless communication terminal may set the number of TIDs of the multiple TID a-MPDUs based on the maximum number of TID information described above. Specifically, 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 TID maximum number from the association response frame or the authentication response frame. In addition, in DL transmission, the wireless communication terminal may obtain information of TID maximum number from an association request frame or an authentication request frame.

In the embodiment of fig. 16 (a), a non-AP wireless communication terminal transmits multiple TID a-MPDUs to an AP in UL SU transmissions. At this time, the non-AP wireless communication terminal obtains the HE capability information element from an association response (assoc. In addition, the non-AP wireless communication terminal obtains the maximum amount of TID information from the maximum TID field number of the HE capability information element. In this case, the maximum amount of TID information is 4. Thus, the non-AP wireless communication terminal transmits a multi TID a-MPDU having 4 TIDs or less to the AP.

In the embodiment of fig. 16 (b), the AP transmits multiple TID a-MPDUs to the non-AP wireless communication terminal in a DL SU transmission. At this time, the AP obtains the HE capability information element from the 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 having 4 TIDs or less to the AP.

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

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

Further, the wireless communication terminal preferentially aggregates MPDUs having TIDs corresponding to the primary AC, and MPDUs having non-primary AC TIDs whose counter values are relatively low among TIDs stored in the EDCA queue to generate an a-MPDU. Further, the wireless communication terminal 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.

Fig. 17 (a) shows the 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 a transmission opportunity is ac_vi. Thus, the master 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 with TIDs corresponding to the primary ac_vi and management frames/control frames to generate a-MPDUs. Thus, the first station STA1 aggregates MPDUs and MMPDUs with TID 2 corresponding to ac_vi to generate a-MPDUs. In the embodiment of fig. 17 (c), the first station STA1 aggregates MPDUs with TIDs corresponding to the primary AC, MPDUs with TIDs corresponding to the AC with a higher user priority than the primary AC, and management frames/control frames to generate a-MPDUs. Thus, the first station STA1 aggregates MPDUs with TID 2 corresponding to ac_vi, MMPDU, and MPDUs with 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 primary AC and TIDs having relatively small counter values among TIDs stored in the EDCA queue to generate a-MPDUs. In the embodiment of fig. 17, the counter values of TIDs stored in EDCA queues are small in the order ac_vi, ac_be, and ac_vo. Thus, the first station STA1 aggregates MPDUs with TID 2 corresponding to ac_vi, MMPDU, MPDUs with TID 4 corresponding to ac_be, and MPDUs with TID 1 corresponding to ac_vo to generate an a-MPDU.

The wireless communication terminal may transmit a Block Ack (BA) frame indicating whether a plurality of MPDUs is 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 MPDUs corresponding to one TID (multi-STA single TID) are received from each of the plurality of wireless communication terminals. The M-BA frame may include per AID TID information subfield indicating whether the reception of each AID and TID 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 was 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 conventional wireless communication terminal can indicate whether a fragment included in each of the 64 MSDUs is received by using a block ACK bitmap field having a length of 128 bytes. Specifically, the conventional wireless communication terminal allocates 1024-bit block ACK bitmap field 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. Accordingly, the conventional wireless communication terminal sets the fragment number field of the block ACK starting sequence control field as the reserved field, and may 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 segmentation level. Specifically, when the segmentation 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 or not an MSDU is received. In addition, when the segment 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 indicating 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. Specifically, the wireless communication terminal may set a Least Significant Bit (LSB) of a fragment number subfield of the block ACK starting sequence control subfield to 0 to indicate that bits of the block ACK bitmap field are divided in sequence units. In addition, the wireless communication terminal may set LSB of the fragment number subfield of the block ACK starting sequence control subfield to 1 to indicate that bits of the block ACK bitmap field are divided in units of fragments. In addition, the wireless communication terminal may indicate the length of the block ACK bitmap field through the block ACK starting sequence control subfield. In particular, the wireless communication terminal may set a value of LSB two bits (lsb+1, lsb+2) 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 BA information fields in which the number TID of TIDs transmitted by the plurality of wireless communication terminals is repeated.

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

When the fragmentation level is determined to be 2 or more through the above-described fragmentation level negotiation, the initiator may transmit an a-MPDU having the fragmentation of the fragmentation level 2. At this time, the receiver may transmit a BA frame including a bitmap indicating whether the 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 fragments such as fragment numbers. For example, in the embodiment of fig. 19 (a), the initiator transmits an a-MPDU comprising 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 through 15. At this time, the bitmap included in the multi-STA BA frame indicates whether all the 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 transmits only some fragments of the MSDU corresponding to sequence number 15, but the bitmap included in the multi-STA BA frame does not indicate the fragment number of the corresponding fragment.

Thus, in order for the initiator to process a bitmap indicating whether a sequence unit is received, the initiator needs to store information identifying fragments or sequences transmitted by the initiator. Thus, depending on the initiator's functionality, the initiator may not be able to process a bitmap indicating whether sequence units are received. For example, the initiator may have to delete or retransmit stored fragments depending on whether the recipient received the respective fragment. In particular, the initiator may have to retransmit fragments of the same size as previously transmitted fragments. For this reason, the initiator needs to track 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 fragments of the same sequence have the same size except for the last fragment. However, if the initiator uses dynamic segmentation, the initiator may need to store the sum of the segment sizes sent by each sequence. In dynamic segmentation, this is because even fragments of the same sequence may have different sizes. In addition, the wireless communication terminal cannot signal whether the wireless communication terminal can process a bitmap indicating whether a sequence unit is received using information indicating a segmentation level supported by the wireless communication terminal. Whether the bitmap indicating the sequence units received can be processed is independent of whether the fragment can be received.

Accordingly, the wireless communication terminal can receive a BA frame including a bitmap indicating whether a sequence unit is received from an originator to signal whether the bitmap indicating whether the sequence unit is received can be processed. For convenience of explanation, information indicating whether or not a bitmap indicating whether or not a sequence unit is received can be processed is referred to as a sequence unit ACK capability indicator. The wireless communication terminal may use the management frame to signal the sequence unit ACK capability indicator 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 be able to signal that the wireless communication terminal is able to process a bitmap indicating whether sequence units are received by setting the indicator with full ACK capability as described above to 1. At this time, the HE capability information element may include all ACK capability indicators as in the embodiment of fig. 19 (b). As in the embodiment of fig. 19 (c), when the full ACK capability indicator is 0, although the receiver receives an a-MPDU having a fragment of fragment level 2, it is unable to 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 capability required by the receiver to process the bitmap indicating whether sequence units are received may be different. Specifically, when the receiver is able to process all ACKs, although the receiver is able to process a bitmap indicating whether sequence units are received, in the case where the receiver is able to process a bitmap indicating whether sequence units are received, the receiver may not be able to process all ACKs. Thus, the wireless communication terminal can signal the sequence unit ACK capability indicator separately from the overall ACK capability indicator. At this time, the HE capability information element may include a sequence unit ACK capability indicator (segment level 2ACK is enabled) as in the embodiment of fig. 20 (a).

In the embodiment of fig. 20 (b), all ACK indicators sent by the initiator are 0, and the sequence unit ACK capability indicator is also 0. In this case, the recipient may transmit a BA frame including a bitmap indicating whether the 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 recipient may transmit a BA frame including a bitmap indicating whether the 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 recipient may send all ACKs.

The initiator 2101 inserts a plurality of MPDUs into the a-MPDU (S2101). Specifically, initiator 2101 may generate fragments by fragmenting an MSDU, an A-MSDU, or an MMPDU. At this point, 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 a 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 a segment level according to an embodiment for the segment level negotiation procedure described above.

In addition, the initiator 2101 may transmit multiple TID a-MPDUs. At this time, the initiator 2101 aggregates MPDUs having TIDs corresponding to the primary AC and MPDUs having TIDs different from the non-primary AC TIDs corresponding to the primary AC to generate an a-MPDU based on the maximum length that the a-MPDU can have in the corresponding transmission opportunity. Specifically, the initiator 2101 may insert all MPDUs with TIDs corresponding to the primary AC stored in the buffer into the a-MPDU and insert MPDUs with non-primary AC TIDs within the maximum length the a-MPDU can have in the transmission opportunity. In particular embodiments, the initiator 2101 may insert MPDUs with non-master AC TIDs into the 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 AC of the MPDU that obtained the transmission opportunity. For example, the initiator 2101 may aggregate MPDUs with TIDs corresponding to the master AC and MPDUs with non-master AC TIDs corresponding to an AC higher than the user priority of the master AC to generate an a-MPDU. Further, the initiator 2101 aggregates MPDUs having TIDs corresponding to the primary ACs 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 the 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 the 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 primary AC into an a-MPDU having a priority next to that of an MPDU having a TID corresponding to the primary AC and transmits the a-MPDU. In addition, the initiator 2101 may aggregate MPDUs with TIDs corresponding to the master AC and MPDUs with non-master AC TIDs corresponding to AC of higher user priority than the master AC, and manage frames/control frames to generate a-MPDUs. Specifically, the initiator 2101 may preferentially insert management frames or control frames into the a-MPDU and insert MPDUs having TIDs corresponding to the primary AC and MPDUs having TIDs other than the primary AC into the a-MPDU. At this time, as described above, the initiator 2101 may insert all MPDUs having TIDs corresponding to the primary AC stored in the buffer into the a-MPDU, and insert MPDUs having non-primary AC TIDs within the maximum length that the a-MPDU can have in the 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 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 the specific operation of the embodiment described with reference to fig. 17.

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

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

In another particular embodiment, the initiator 2101 may store all fragments of the corresponding previously generated MSDU until the last fragment of the MSDU is generated. Initiator 2101 can generate a new fragment based on all fragments of the corresponding previously generated MSDU. Specifically, initiator 2101 can determine a fragmentation starting point for a new fragment based on all fragments of the corresponding previously generated MSDUs. In addition, the initiator 2101 may assign fragment numbers to the new fragments based on all fragments of the corresponding previously generated MSDUs. The specific operation of the initiator 2101 may be the same as the specific operation 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, initiator 2101 can generate all fragments for any one MSDU in the same transmission opportunity. The specific operation of the initiator 2101 may be the same as the specific operation of the embodiment described with reference to fig. 14.

In addition, the initiator 2101 can 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 can process full 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 or not a bitmap, which the initiator can process data, is received in units of a sequence. The energy information indicating whether the bitmap of data in units of sequence can be processed may be the sequence unit ACK capability indicator described above. Initiator 2101 can 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 of indicating whether or not a bitmap indicating whether or not data is received in sequence units can be processed.

The receiver 2103 receives an a-MPDU comprising a plurality of MPDUs from the initiator 2101. Specifically, the receiver 2103 may receive an a-MPDU comprising fragments from the initiator 2101. The receiver 2103 transmits a BA frame to the initiator based on MPDUs included in the received a-MPDUs. At this time, the receiver 2103 may determine the format of the BA frame based on information indicating whether a particular ACK type can be processed. Specifically, the receiver 2103 may determine whether to send a BA frame indicating a full ACK to the receiver based on the full ACK capability indicator. Further, the receiver 2103 may determine whether to transmit a BA frame including a bitmap indicating whether reception is performed in sequence units to the receiver 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, while the methods, apparatus, and systems of the present invention are described in connection with particular embodiments of the present invention, 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. Furthermore, the features, structures, and effects shown in each embodiment may be combined or modified in other embodiments by those skilled in the art. It is therefore to be understood that matters related to such combination and modification are included within the scope of the present invention.

Although the present invention has been described primarily based on the above embodiments without being limited thereto, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present 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 in 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

the processor may be configured to perform the steps of,

wherein the processor is configured to insert a MAC Protocol Data Unit (MPDU) having a Traffic Identifier (TID) corresponding to a primary Access Category (AC) into an aggregated MPDU (a-MPDU),

inserting an MPDU having a non-master AC TID as a TID different from the TID corresponding to the master AC into the a-MPDU 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 corresponding transmission opportunity,

inserting management frames into the A-MPDU, and

the a-MPDU is transmitted to a receiver by using the transceiver.

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

an MPDU having the non-master AC TID corresponding to an AC having a higher user priority than the master AC within the maximum length is inserted into the a-MPDU.

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 MPDUs having a Traffic Identifier (TID) corresponding to the primary AC into an aggregate MAC protocol data unit (a-MPDU);

inserting MPDUs having a non-primary Access Category (AC) TID that is a TID different from the TID corresponding to the primary AC into the a-MPDU based on a user priority corresponding to the TID corresponding to the primary 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 transmitting the A-MPDU to a receiver.

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

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