WO2015037762A1 - High-speed frame exchange method - Google Patents

Abstract

A high-speed frame exchange method that increases the efficiency of a resource and enables reliable transmission is disclosed. A method performed by a terminal includes the steps of: receiving a first downlink data frame including a specific field where a bit value requesting a response using a data frame from an access point is set; and transmitting a second uplink data frame to the access point in response to the first downlink data frame based on the bit value of the specific field. Thus, since it is possible to respond to data frame reception by using another data frame, it is possible to increase the efficiency of a resource.

Description

High speed frame exchange method

The present invention relates to a wireless communication technology, and more particularly, to a high-speed frame exchange method capable of increasing resource efficiency and enabling reliable transmission.

With the development of information and communication technology, various wireless communication technologies are being developed. Among them, wireless local area network (WLAN) is based on radio frequency technology such as personal digital assistant (PDA), laptop computer, portable multimedia player (PMP), etc. It is a technology that allows a user to access the Internet wirelessly at home, a business, or a specific service area by using a portable terminal.

The standard for WLAN technology is developed and standardized by the IEEE 802.11 Working Group (WG) under the Institute of Electrical and Electronics Engineers (IEEE) 802.11 Committee. IEEE 802.11a uses an unlicensed band at 5 GHz, providing a maximum PHY data rate of 54 Mbps. IEEE 802.11b applies a direct sequence spread spectrum (DSSS) at 2.4 GHz to provide a maximum PHY data rate of 11 Mbps. IEEE 802.11g applies orthogonal frequency division multiplexing (OFDM) at 2.4 GHz to provide a maximum PHY data rate of 54 Mbps. IEEE 802.11n provides a maximum PHY data rate of 300 Mbps when using two spatial streams and 40 MHz bandwidth, and four spatial streams and 40 MHz Using bandwidth provides a maximum PHY data rate of 600 Mbps.

As the spread of the WLAN is activated and the applications using the same are diversified, there is an increasing need for a new WLAN technology for supporting a higher throughput than the data processing speed supported by IEEE 802.11n. Very high throughput (VHT) WLAN technology is one of the 802.11 WLAN technology, has been proposed to support data processing speed of 1 Gbps or more. Among them, IEEE 802.11ac is being developed as a standard for providing very high throughput in the 5 GHz band, and IEEE 802.11ad is being developed as a standard for providing very high throughput in the 60 GHz band.

In a system based on the WLAN technology, 802.11ah is under study for the purpose of communication with a sensor, a meter, and the like.

Since sensor nodes are larger than general terminals, collisions are more likely to occur during channel access, and battery replacement is difficult.

For this reason, channel access and power saving are very important issues in IEEE 802.11 ah.

However, in IEEE 802.11, channel access schemes having low resource efficiency are generally used. For example, when a terminal (or an access point) transmits a data frame while the terminal and the access point communicate with each other, the access point (or terminal) transmits an acknowledgment (ACK) frame or blocks in response thereto. A block acknowledgment (BA) frame is sent to indicate that the data frame was successfully received.

However, when more data bits of the frame control field in the MAC header are set to 1 and there are consecutive data frames to be transmitted, the access point (or terminal) of the receiving end The acknowledgment frame or block acknowledgment frame transmitted by) may reduce resource efficiency.

That is, since the acknowledgment frame or the block acknowledgment frame is not data that the terminal (or access point) wants to receive, the data frame cannot be transmitted during the time of transmitting the acknowledgment frame, thereby reducing resource efficiency.

An object of the present invention for solving the above problems is to provide a high-speed frame exchange method that can increase the resource efficiency.

Another object of the present invention is to provide a high speed frame exchange method capable of reliable data transmission.

According to a high speed frame exchange method according to an embodiment of the present invention for achieving the above object, in a method performed in the terminal, comprising a specific field set the bit value requesting to respond to the data frame from the access point Receiving a first downlink data frame and transmitting a second uplink data frame to the access point in response to the first downlink data frame based on a bit value of the specific field.

Here, the step of receiving a first downlink data frame including a specific field that sets a bit value requesting to respond to the data frame from the access point may include an acknowledgment field and an acknowledgment to request to respond with a data frame. The first downlink data frame in which the bit value of the indication field or the response frame field is set to binary 11 may be received.

The acknowledgment field, the acknowledgment field, or the response frame field may include an acknowledgment (ACK) when the bit value of the acknowledgment field, the acknowledgment field, or the response frame field is binary 00, and a block acknowledgment (01). Block ACK, BA), in case of 10, it can mean no response, and in case of 11, it responds with a data frame.

The transmitting of the second uplink data frame to the access point may include setting a bit of a specific field in a second uplink data frame based on more data bits in the first downlink data frame; The method may further include setting more data bits of the second uplink data frame based on whether there is data to be transmitted, and transmitting the second uplink data frame to the access point.

Here, the setting of the bit of the specific field of the second uplink data frame based on the more data bit in the first downlink data frame may include setting the bit of the more data bit in the first downlink data frame to 1; 2, the bit of the specific field in the uplink data frame may be set to 11, and when the more data bit in the first downlink data frame is 0, the bit of the specific field in the second uplink data frame may be set to 00.

Here, before receiving a first downlink data frame including a specific field in which a bit value is set to request a response to the data frame from the access point, the first uplink data having the more data bit set to 1 The method may further include transmitting the frame to the access point.

Here, in the transmitting of the first uplink data frame having the more data bit set to 1 to an access point, a bit value of a specific field in the first uplink data frame is set to binary 00 or 11, and the more The first uplink data frame having the data bit set to 1 may be transmitted to the access point.

In addition, according to the high-speed frame exchange method according to another embodiment of the present invention, receiving an Ack frame in which the bit value of the ACK policy field is set to binary 11 from the access point, and the second uplink data frame Setting a bit value of an acknowledgment field in the binary number 00, setting a MoreData bit of the second uplink data frame based on whether there is additional data to transmit, and the second uplink Sending a link data frame to the access point.

Here, the bits of the Ack policy field may include an ACK when the bit value of the Ack policy field is 00, a block BA when 01, a No Response when 10, and a data when 11 Each may mean responding with a frame.

Here, prior to the step of receiving an Ack frame in which the bit value of the Ack policy field is set to binary 11 from the access point, the MoreData bit is set to 1 and the bit value of the Ack policy field is set to 2. The method may further include transmitting a first uplink data frame set to 00 in the access point.

In addition, according to the high-speed frame exchange method according to another embodiment of the present invention, the MoreData bit is set to 1 and the bit value of the ACK policy field is set to binary 11 from the access point. Receiving a downlink data frame, determining whether a second uplink data frame can be transmitted in response to the first downlink data frame, and based on the determination result, the second uplink data Setting bits of the response frame field included in the frame, setting more data bits of the second uplink data frame based on whether there is additional data to transmit, and the second uplink data Sending a frame to the access point.

Here, the bits of the Ack policy field may include an ACK when the bit value of the Ack policy field is 00, a block BA when 01, a No Response when 10, and a data when 11 Each may mean responding with a frame.

Here, before receiving the first downlink data frame in which the more data bit is set to 1 from the access point and the bit value of the acknowledgment field is set to binary 11, the first uplink having the more data bit is set to 1; The method may further include transmitting a link data frame to the access point.

The determining of whether the second uplink data frame can be transmitted in response to the first downlink data frame may include transmitting the second uplink data frame based on a preset frame transmission / reception time limit. It can be determined.

In addition, according to the high-speed frame exchange method according to another embodiment of the present invention, in the frame exchange method performed in the terminal, failing to receive a first downlink data frame from the access point, and the first downlink Determining whether the reception of the first downlink field in the link data frame was successful; and if the reception of the specific field is successful, transmitting a second uplink data frame to the access point based on the first downlink field. It includes.

In this case, the first downlink field is whether a 1-bit acknowledgment bit indicating whether the terminal receives the first uplink data frame transmitted before the second uplink data frame and the first downlink data frame are retransmitted. It may be a first downlink signal field (SIG field) in which a retransmission indication bit of 1 bit indicating whether or not is set.

Here, the second uplink data frame sets a 1-bit acknowledgment bit indicating that the reception of the first downlink data frame has failed and a 1-bit retransmission indication bit indicating that the currently transmitted data frame is not retransmitted. It may include a first uplink signal field (SIG field).

Here, after the step of transmitting the second uplink data frame to the access point, receiving a second downlink data frame from the access point and of the second downlink field included in the second downlink data frame Based on a retransmission indication bit, if it is determined that the second downlink data frame is a retransmission frame of the first downlink data frame, chase combining is performed on the first downlink data frame and the second downlink data frame. The method may further include combining.

According to the apparatus for performing the fast frame exchange method and the fast frame exchange method according to an embodiment of the present invention as described above, a first downlink in which a bit of a specific field requesting to respond to a data frame from an access point is set to 11 Receives a link data frame and transmits a second uplink data frame to the access point in response to the first downlink data frame based on the received data frame response request. In addition, the terminal transmits a data frame in which a retransmission instruction bit indicating whether the data frame is retransmitted and a bit indicating whether the data frame transmission is successful.

Therefore, the data frame response can be used instead of the acknowledgment of the data reception, thereby increasing the efficiency of the resource and enabling reliable data transmission.

1 is a conceptual diagram illustrating an embodiment of a configuration of an IEEE 802.11 WLAN system.

2 is a conceptual diagram illustrating a combining process for data transmission in a WLAN system.

3 illustrates a 2-bit setting of an ACK policy for performing a fast frame exchange method according to an embodiment of the present invention.

4 is a conceptual diagram illustrating a fast frame exchange method according to an embodiment of the present invention when the terminal transmits a PS-poll frame.

5 is a conceptual diagram illustrating a fast frame exchange method according to an embodiment of the present invention when there is up and down transmission data.

6 is a flowchart illustrating a fast frame exchange method performed in a terminal according to an embodiment of the present invention.

7 is a conceptual diagram illustrating a fast frame exchange method according to an embodiment of the present invention when the number of up-down transmission data is different.

8 is a flowchart illustrating a fast frame exchange method performed in a terminal according to another embodiment of the present invention.

9 is a conceptual diagram illustrating a high speed frame exchange method according to an embodiment of the present invention when the data frame transmission time is limited.

10 is a flowchart illustrating a high speed frame exchange method performed in a terminal when there is a frame transmission / reception time limit according to an embodiment of the present invention.

11 is a conceptual diagram illustrating a data retransmission method when a data frame transmission fails.

12 is a conceptual diagram illustrating a data frame in which SfeACK and retransmission indication bits are defined according to an embodiment of the present invention.

13 is a conceptual diagram illustrating a data retransmission method when a data frame transmission fails according to an embodiment of the present invention.

14 is a conceptual diagram illustrating a data retransmission method performed by a terminal when a data frame transmission fails according to an embodiment of the present invention.

15 is a conceptual diagram illustrating that the high speed frame exchange is stopped when the access point and the terminal continuously fail to transmit data.

16 is a conceptual diagram illustrating that high-speed frame exchange is stopped when two consecutive transmissions of a terminal fail.

As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. In the following description of the present invention, the same reference numerals are used for the same elements in the drawings and redundant descriptions of the same elements will be omitted.

Throughout the specification, a station (STA) is a physical layer for medium access control (MAC) and wireless medium that conforms to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. By any functional medium that includes an interface. The station STA may be divided into a station that is an access point (AP) and a station that is a non-access point (STA). A station (STA), which is an access point (AP), may simply be called an access point (AP), and a station (STA), which is a non-AP, may simply be called a terminal.

The terminal may include a processor and a transceiver, and may further include a user interface and a display device. A processor refers to a unit designed to generate a frame to be transmitted through a wireless network or to process a frame received through a wireless network, and performs various functions for controlling a station (STA). A transceiver is a unit that is functionally connected to a processor and is designed to transmit and receive a frame through a wireless network for a station (STA).

An access point (AP) may refer to a centralized controller, a base station (BS), a node-B, an e-node-B, a base transceiver system (BTS) or a site controller, and the like. Some or all of the features may be included.

The terminal may be a user equipment (UE), a mobile station (MS), a user terminal (UT), a wireless terminal, an access terminal (AT), a terminal, a subscriber unit, a subscriber. It may be referred to as a Subscriber Station (SS), a wireless device, a wireless communication device, a Wireless Transmit / Receive Unit (WTRU), a mobile node, mobile or other terms. Various embodiments of the terminal may be photographed such as a cellular telephone, a smart phone having a wireless communication function, a personal digital assistant (PDA) having a wireless communication function, a wireless modem, a portable computer having a wireless communication function, or a digital camera having a wireless communication function. Devices, gaming devices with wireless communications capabilities, music storage and playback appliances with wireless communications capabilities, Internet appliances with wireless Internet access and browsing, as well as portable units or terminals incorporating combinations of such functions. It may include, but is not limited thereto.

1 is a conceptual diagram illustrating an embodiment of a configuration of an IEEE 802.11 WLAN system.

Referring to FIG. 1, an IEEE 802.11 WLAN system includes at least one basic service set (BSS). BSS means a set of stations (STA 1, STA 2 (AP 1), STA 3, STA 4, STA 5 (AP 2)) that can be successfully synchronized to communicate with each other, the concept of a specific area is no.

BSS can be classified into Infrastructure BSS (Independent BSS) and Independent BSS (IBSS), and BSS 1 and BSS 2 represent Infrastructure BSS. BSS 1 connects a terminal (STA 1), an access point (STA 2 (AP 1)) providing a distribution service and a plurality of access points (STA 2 (AP 1), STA 5 (AP 2)) It may include a distribution system (DS). In BSS 1, an access point STA 2 (AP 1) manages a terminal STA 1.

BSS 2 connects a terminal (STA 3, STA 4), an access point (STA 5 (AP 2)) providing a distribution service and a plurality of access points (STA 2 (AP 1), STA 5 (AP 2)) It may include a distribution system. In BSS 2, an access point STA 5 (AP 2) manages terminals STA 3 and STA 4.

Meanwhile, an independent BSS (IBSS) is a BSS operating in an ad-hoc mode. Since the IBSS does not include an access point, there is no centralized management entity. That is, in the IBSS, terminals are managed in a distributed manner. In the IBSS, all terminals may be mobile terminals, and thus, are not allowed to be connected to the distribution system (DS), thereby forming a self-contained network.

The access points STA 2 (AP 1) and STA 5 (AP 2) provide access to the distributed system DS through the wireless medium for the terminals STA 1, STA 3, and STA 4 coupled thereto. . Communication between terminals STA 1, STA 3, and STA 4 in BSS 1 or BSS 2 is generally performed through an access point STA 2 (AP 1) or STA 5 (AP 2), but a direct link (direct link) If the link is configured, direct communication between the terminals STA 1, STA 3, and STA 4 is possible.

The plurality of infrastructure BSSs may be interconnected through a distribution system (DS). A plurality of BSSs connected through a distribution system (DS) is called an extended service set (ESS). Stations included in the ESS may communicate with each other, and the UE may move from one BSS to another BSS while seamlessly communicating within the same ESS.

The distribution system (DS) is a mechanism for one access point to communicate with another access point, whereby the access point transmits frames to, or moves to, another BSS for the terminals that are associated with the BSS it manages. A frame may be transmitted for one arbitrary terminal. In addition, the access point may transmit and receive frames with an external network such as a wired network. Such a distribution system (DS) does not necessarily need to be a network, and there is no limitation on its form as long as it can provide a predetermined distribution service defined in the IEEE 802.11 standard. For example, the distribution system may be a wireless network such as a mesh network or a physical structure that connects access points to each other.

The high-speed frame exchange method according to an embodiment of the present invention to be described later can be applied to the IEEE 802.11 WLAN system described above, and in addition to the IEEE 802.11 WLAN system, a wireless personal area network (WPAN) and a wireless body area network (WBAN). It can be applied to various networks such as).

2 is a conceptual diagram illustrating a combining process for data transmission in a WLAN system.

In order for the STA to transmit and receive data in the intra-structure BSS, the terminal STA must first be associated with the access point AP.

Referring to FIG. 2, the association process of the STA in the infrastructure BSS is largely 1) a probe step (AP), and 2) an authentication step with the detected access point (AP). ) And 3) an association step with an authenticated access point (AP).

The STA may first detect neighboring access points (APs) through a detection process. The detection process is divided into a passive scanning method and an active scanning method. The passive scanning method may be performed by overhearing beacons transmitted by neighboring access points (APs). Meanwhile, the active scanning method may be performed by broadcasting a probe request frame. The AP that receives the probe request frame may transmit a probe response frame corresponding to the probe request frame to the corresponding STA. The STA may know the presence of neighboring access points (APs) by receiving a probe response frame.

Thereafter, the terminal STA may select one access point AP among the plurality of detected access points and perform authentication with the selected access point AP. An authentication algorithm according to the IEEE 802.11 standard is divided into an open system algorithm for exchanging two authentication frames and a shared key algorithm for exchanging four authentication frames. Through the process of exchanging an authentication request frame and an authentication response frame based on the authentication algorithm, the terminal STA may perform authentication with the access point AP.

Finally, the STA performs a connection process with an authenticated access point (AP). That is, the terminal STA transmits an association request frame to the selected access point AP, and the access point AP that receives the association request frame receives an association response frame corresponding to the association request frame. frame is transmitted to the corresponding STA. As such, through the process of exchanging the connection request frame and the connection response frame, the STA may perform a connection process with the access point AP.

3 illustrates a 2-bit setting of an ACK policy for performing a fast frame exchange method according to an embodiment of the present invention.

When a terminal (or an access point) continuously transmits a data frame, an ACK frame or a block BA frame for a previously transmitted data frame is a data frame that the terminal (or access point) wants to receive. In other words, it is not possible to transmit a data frame during a time when an ACK frame or a block BA frame is received, thereby reducing resource efficiency. Therefore, in order to solve this problem, a method of transmitting a data frame serving as an acknowledgment frame in response to the received data frame will be described.

Referring to FIG. 3, an access point (or a terminal) displays a binary frame 00 in two bits of an ACK policy field, an acknowledgment frame response by displaying a 01, a block acknowledgment response by displaying a 01, and a non-response by 10. Alternatively, 11 may be requested to request the receiver to respond with a data frame.

In detail, the access point (or terminal) may transmit a data frame by displaying binary 00 in two bits of an ACK policy field to receive an acknowledgment frame from the terminal (or access point).

Alternatively, the access point (or terminal) may transmit a data frame by displaying binary 01 in two bits of the acknowledgment field to receive a block ac (BA) frame from the terminal (or access point), and the terminal (or access) When an Ack frame is received from a point), the data frame may be transmitted by displaying a binary number 10 in 2 bits of the Ack policy field, which means that it does not need to respond.

Alternatively, the access point (or terminal) may transmit a data frame by displaying binary 11 in two bits of the acknowledgment field in order to receive the data frame from the terminal (or access point).

Here, the access point (or terminal) transmits a data frame indicating binary 00, 01, 10, or 11 in two bits of an ACK indication and a response frame field (RSPFrm) in addition to the acknowledgment field. It may be.

In addition, the access point (or terminal) in order to indicate that there are additional data frames to be transmitted in addition to the previously transmitted frame, the MoreData bit of the Frame Control Field in the MAC header (MAC Header) bit) can be set to 1 to transmit the data frame.

4 is a conceptual diagram illustrating a fast frame exchange method according to an embodiment of the present invention when the terminal transmits a PS-poll frame.

Even if there is no data frame to transmit to the access point, the terminal may transmit a PS-poll to the access point to check whether there is a data frame to receive from the access point.

Referring to FIG. 4, the terminal transmits a PS-poll to the access point.

The access point is a response to the PS-poll received from the terminal. When there is data to be transmitted by the access point, the access point sets the more data bit to 1 and the bit frame of the response frame field (RspFrm field) to binary 11 Send to the terminal.

Here, the neighboring terminals overhearing that the bit value of the response frame field is set to binary 11 may set a network allocation vector (NAV) for a preset time, thereby preventing collision in the channel. You can prevent it. In this case, the preset time may be, for example, MAX_PPDU + 2 * SIFS + PHY-RXSTARTDelay.

The access point transmits a data frame to the terminal after a short interframe space (SIFS).

Here, the data frame transmitted by the access point indicates that there is no data transmitted to the terminal by setting more data to 0 (MoreData = 0), and the terminal is set by setting the bit of the response frame field to 00 (RspFrm = 00). Request to send an ac frame.

Since the more data bit of the data frame received from the access point is set to 0 and the acknowledgment frame to be transmitted to the access point does not require a separate acknowledgment frame response, the UE may determine the response frame field (RspFrm) of the acknowledgment frame field in the ac frame. An Ack frame with bit set to 10 can be sent to the access point and enter doze mode.

According to an embodiment of the present invention, after the access point receives the PS-poll from the terminal, it does not prepare a data frame in the short interframe space (SIFS), and notifies that there is data to be transmitted through the acknowledgment frame and transmits the data frame. An example has been described. However, if the access point can prepare the data frame in the short interframe space (SIFS) after receiving the PS-poll, it is obvious that the data frame can be transmitted to the terminal after the short interframe space.

5 is a conceptual diagram illustrating a fast frame exchange method according to an embodiment of the present invention when there is up and down transmission data.

Referring to FIG. 5, since there is additional data to be transmitted, the terminal transmits the first uplink data frame UL1 having the more data bit set to 1 and the bit of the response frame field set to 00 to the access point.

When the first uplink data frame UL1 is received, the access point may transmit a data frame to the terminal instead of the acknowledgment frame because the data frame may function as an acknowledgment frame.

In this case, since the access point has additional data to be transmitted, the more data bit in the first downlink data frame DL1 is set to 1, and the terminal confirms that there is additional data to be transmitted through the first uplink data frame UL1. The bit of the response frame field may be set to 11.

The terminal may transmit the data frame to the access point in response to the more data bit in the first downlink data frame DL1 received from the access point and set the bit in the response frame field to 11. In this manner, the access point and the terminal may transmit and receive UL2, DL2, and UL5.

When the terminal transmits the last fifth downlink data frame UL5 to the access point, since there is no more data to transmit, the terminal sets the more data bit to zero. In addition, since the more data bit is set to 1 in the fourth downlink data frame DL4 transmitted by the access point, the terminal sets the bit in the response frame field of the last fifth downlink data frame UL5 to 11. Can be.

The access point determines that there is no data frame to be transmitted by the UE through the received fifth uplink data frame UL5, and sets the more data bit to 0 and the fifth downlink to set the bit in the response frame field to 00. The link data frame DL5 is transmitted to the terminal.

Since the UE and the access point no longer have a data frame to transmit, the Ack frame in which the gather data bit is set to 0 and the bit in the response frame field is set to 10 in response to the fifth downlink data frame DL5 is set to the access point. send.

According to an embodiment of the present invention, it is possible to continuously exchange frames without a separate acak frame or a block acak frame through the above-described method it is possible to improve the resource efficiency.

6 is a flowchart illustrating a fast frame exchange method performed in a terminal according to an embodiment of the present invention.

Referring to FIG. 6, the terminal transmits a data frame in which the MoreData bit is set to 1 to the access point (S610).

Here, the terminal sets the more data bit to 1 because there are additional data frames to be transmitted to the access point. In addition, the terminal may set the bit of the acknowledge policy field in the data frame to 00 or 11.

In response to the data frame transmitted in step 610, the terminal receives a data frame in which the bit of the acknowledgment field is set to 11 from the access point (S620).

Here, since the UE sets the more data bit to 1, that is, there is an additional data frame, the UE may receive a data frame in which the bit of the acknowledgment field is set to 11 from the access point. In addition, even when the terminal transmits a data frame in which the bit of the acknowledgment field is set to 00 to the access point in step 610, if the access point has data to be transmitted, the data frame is received from the access point instead of the acknowledgment frame in step 620. can do.

Thereafter, the terminal determines whether the more data bit in the data frame received through step 620 is 1 (S630).

When the terminal determines that the more data bit in the data frame is 1 through step 630, since the access point has additional data to transmit, the terminal sets the bit in the acknowledgment field to 11 to respond to the data frame (S640). .

Alternatively, if it is determined in step 630 that the more data bits in the data frame are 0, the access point does not have any additional data to transmit, and thus sets the bit in the acknowledgment field to 00 to respond with an acknowledgment frame (S650). ).

Thereafter, the terminal determines whether there is additional data to be transmitted to the access point (S660).

If it is determined that there is no additional data to be transmitted to the access point through step 660, the terminal sets the more data bit to 0 (S670).

The terminal transmits a data frame including the bits of the Ack policy field and the more data bits set through the steps 640 and 670 or the steps 650 and 670 to the access point (S680).

Or, if it is determined that there is additional data to be transmitted to the access point in step 660, the terminal sets the more data bit to 1 (S690), and returns to step 610 to perform again from step 610.

According to the fast frame exchange method according to an embodiment of the present invention, 11 of 2 bits of the acknowledgment field instead of transmitting Not ACK, CTS or BA, that is, arc, clear to send, block ac Newly defined as requesting a response to a data frame. Therefore, when there are a plurality of data frames to be transmitted to the terminal and the access point to each other, the process of transmitting the data frame in response to the data frame is repeatedly performed to reduce the overhead caused by Ack frame transmission.

7 is a conceptual diagram illustrating a fast frame exchange method according to an embodiment of the present invention when the number of up-down transmission data is different.

Referring to FIG. 7, the terminal may confirm that there is a data frame to be received from the access point through the beacon of the access point.

Thereafter, the terminal additionally sets the more data bit to 1 because there are data frames to be transmitted, and transmits the data frame UL1 having the bit in the response frame field to 11 to the access point because there is data to be received from the access point.

As illustrated in FIG. 5, the terminal and the access point may transmit and receive an uplink data frame and a downlink data frame through fast frame exchange.

After the access point transmits to the terminal up to the last DL data frame (DL4), since there are no more data frames to transmit, the more data bit is set to 0, and since there is additional data to be received from the terminal, the bit in the response frame field is 11 The downlink data frame DL4 is set to the terminal.

When the downlink data frame DL4 is received from the access point, the terminal sets the bit in the response frame field to 00 and transmits the data frame UL5 in which the more data bit is set to 1 to the access point.

In this case, since the UE knows that the access point transmits the Ack frame to the data frame UL5 transmitted by the terminal through the more data bit in the received downlink data frame DL4, the bit in the response frame field is set to 00. Can be set.

The AP recognizes that there is a data frame to be additionally transmitted by the UE through the received UL data frame UL5, and sets 11 to the bit of the response frame field, and sets the more data bit to 0 since there is no additional data to transmit. Send to the terminal.

Thereafter, the terminal may set the more data bit to 0 and transmit the last data frame UL5 having the bit in the response frame field to 00 to the access point.

In contrast, the access point transmits an ac frame in which the more data bit is set to 0 and the bit in the response frame field is set to 10, so that the terminal no longer responds to the ac frame of the access point.

8 is a flowchart illustrating a fast frame exchange method performed in a terminal according to another embodiment of the present invention.

Hereinafter, the access point will be described on the assumption that there are no data frames to transmit.

Referring to FIG. 8, the terminal transmits a data frame in which the more data bit is set to 1 and the bit of the acknowledgment field is set to 00 (S810).

In this case, the UE may set the more data bit to 1 because there are additional data frames to transmit, and since the access point has no additional data to transmit, the bit may set the bit in the acknowledgment field to 00.

Thereafter, the terminal receives an Ack frame in which the bit of the Ack policy field is set to 11 from the access point (S820), and sets the bit of the Ack polish to 00 based on the received Ack frame (S830).

The terminal determines whether there are additional data frames to transmit to the access point (S840).

If it is determined in step 840 that there are no additional data frames to transmit to the access point, the terminal sets the more data bit to 0 (S850).

The terminal sets the bits of the policy to 00 through steps 830 and 850 and transmits a data frame in which the more data bits are set to 0 to the access point (S860).

Thereafter, the terminal receives an Ack frame in which the bit of the policy is 10 from the access point in response to the data frame transmitted in step 860 (S870).

Alternatively, if it is determined that there is an additional data frame to be transmitted to the access point in step 840, the terminal sets the more data bit to 1 (S880), and returns to step 810 to perform again from step 810.

9 is a conceptual diagram illustrating a high speed frame exchange method according to an embodiment of the present invention when the data frame transmission time is limited.

In general, since radio resources are limited and must be shared with other terminals or access points, an environment in which a specific time interval for communicating with a specific terminal or access point may be limited. In such a case, an environment in which the terminal or the access point should stop transmitting data that it has due to time limitation may occur.

For example, the access point may define a time slot for communicating with a specific terminal and inform the terminal of the start point and the end point of the slot. In this environment, the UE starts frame transmission at the start of the slot and must finish the frame transmission before the end of the slot.

Referring to FIG. 9, the terminal transmits a data frame UL1 having the more data bit set to 1 and the response frame bit set to 00 to the access point.

When the data frame UL1 is received from the terminal, the access point transmits the data frame DL1 having the more data bit set to 1 and the response frame bit set to 11 when there is additional data to be transmitted.

Here, the access point should transmit an acknowledgment frame with the response frame bit set to 00 in the data frame UL1 received from the terminal, but the data frame DL1 may serve as an acknowledgment frame. Can be transmitted to the terminal.

In the case of FIG. 9, uplink data frames and downlink data frames may be transmitted and received through fast frame exchange as shown in FIG. 5.

When the terminal receives the data frame DL3 from the access point, since the terminal has additional data to transmit, the terminal may transmit the data frame UL4 having the more data bit set to 1 and the bit in the response frame field to 11 to the access point. have.

In response, the access point transmits the data frame DL4 having the more data bit set to 1 and the bit of the response frame field to 11 since there is additional data to transmit.

Although the terminal additionally has a data frame to transmit, instead of transmitting the data frame transmits the Ack frame to the access point.

In this case, when the terminal determines that the time at which the acknowledgment frame is received from the access point may exceed the data time limit as the data frame is transmitted to the access point, the terminal may transmit the acknowledgment frame to the access point instead of the data frame. . That is, the terminal may exceed the time limit even when the bit of the response frame field of the received data frame is set to 11, and thus may respond with an ac frame instead of the data frame.

10 is a flowchart illustrating a high speed frame exchange method performed in a terminal when there is a frame transmission / reception time limit according to an embodiment of the present invention.

Hereinafter, the terminal assumes that a predetermined frame transmission / reception time, that is, a start point of a time slot for communication and an end point of a time slot are allocated from an access point.

Referring to FIG. 10, the terminal transmits a data frame in which the more data bit is set to 1 to the access point (S1010).

Thereafter, the terminal receives a data frame in which the more data bit is set to 1 and the bit of the acknowledgment field is set to 11 in response to the data frame transmitted in step 1010 (S1020).

When the data frame is received in step 1020, the terminal determines whether data frame transmission is possible to the access point (S1030).

Here, the terminal determines whether data frame transmission is possible based on a preset frame transmission / reception time. For example, when it is determined that the preset frame transmission / reception time is terminated during data frame transmission, when it is determined that the preset frame transmission / reception time is terminated while receiving the acknowledgment for the transmitted data frame, the data frame transmission is impossible. You can judge.

If it is determined that the transmission of the data frame to the access point is not possible through step 1030, the terminal sets the bit of the acknowledgment field to 10 (S1040).

Or, if it is determined that data frame transmission is possible to the access point through step 1030, the terminal sets the bit of the acknowledgment field to 11 (S1050).

Thereafter, the terminal determines whether there is additional data to be transmitted to the access point (S1060).

If it is determined that there is additional data to be transmitted to the access point through step 1060, the terminal sets the more data bit to 1 (S1070).

Or, if it is determined that there is no additional data to be transmitted to the access point through step 1060, the terminal sets the more data bit to 0 (S1080).

Thereafter, the terminal transmits the frame including the set bit to the access point (S1090).

Here, if it is determined that the transmission of the data frame is not possible through step 1030, the terminal may transmit an Ack frame in which the bit of the Acknowledge field is set to 10 and the more data bit is set to 0 or 1 to the access point. Alternatively, if it is determined in step 1030 that data frame transmission is possible, the terminal may set the bit of the acknowledgment field to 11 and transmit the data frame in which the more data bit is set to 0 or 1 to the access point.

According to an embodiment of the present invention, even when the bit of the acknowledgment field in the received data frame is set to 11, the response may be an acknowledgment instead of an acknowledgment of the data frame based on the preset frame transmission / reception time.

11 is a conceptual diagram illustrating a data retransmission method when a data frame transmission fails.

As described above, the fast frame exchange method according to an embodiment of the present invention is a method for enabling a data frame to perform the role of an acknowledgment. However, since the data frame has a longer frame length than the acknowledgment frame, the probability of transmission failure of the data frame is higher than that of the acknowledgment frame. In addition, a bar that may additionally occur when a transmission of a data frame fails will be described below.

Referring to FIG. 11, since the terminal has not received a response to the transmitted data frame UL2, the terminal may determine that the transmission of the data frame has failed, and may retransmit the transmitted data frame UL2.

On the other hand, since the access point also has not received a response to the transmitted data frame DL2, a situation may arise in which the successfully transmitted data frame DL2 needs to be unnecessarily retransmitted.

In addition, the retransmission of the above-described data frame (UL2, DL2) is possible after a certain time using a separate channel approach, there is a problem in terms of resource efficiency.

In general, when a transmission failure of a data frame occurs, some received frames may be discarded because the information of the failed data frame is not reliable. However, if the data frame is broken during the high-speed frame exchange, the data frame plays the role of an ack frame at the same time, so if a separate field can be placed in the data frame to indicate an ack or a ACK / ACK, unnecessary data Retransmission can be prevented to improve resource efficiency.

12 is a conceptual diagram illustrating a data frame in which SfeACK and retransmission indication bits are defined according to an embodiment of the present invention.

Referring to FIG. 12, a separate field in a data frame may be 1-bit among reserved bits of a SIG field. The 1-bit may be defined as a speed frame exchange ACK / NACK (SfeACK) bit, where SfeACK bit is 0, which means NACK, and 1 means ACK. Alternatively, if the SfeACK bit is 0, it may mean an ACK, and if 1, it means NACK.

In addition, one bit of a retransmission indicating bit (RTI bit) may be included in the data frame to determine whether the transmitted data frame is a retransmitted data frame. If the receiver determines that the data frame transmitted from the transmitter is a retransmission data frame through the retransmission indication bit, chase combining may be performed. Here, chace combining has an advantage that data frames can be read well using previously received data frames and retransmitted data frames.

Here, if one bit of the retransmission indication bit is 0, it may mean a data frame that is not retransmission, and if it is 1, it may mean a data frame that is retransmission. Alternatively, if one bit of the retransmission indication bit is 0, this may mean a data frame that is a retransmission, and a value of 1 may mean a data frame that is not retransmission.

The SIG field has a separate Cyclic Redundancy Check (CRC) field and is transmitted in a very robust manner (e.g. BPSK or QPSK + 1/2 Convolutional Code rate). . On the other hand, the data portion may be transmitted in a higher-order transmission scheme (eg, 64-QAM + 3/4 Convolutional Code rate).

In general, when transmitting in a higher-order transmission method, a large amount of data can be transmitted at a high speed, but there is a weak point to channel error.

The signal field generally uses a low Modulation and Coding Scheme (MCS) level, and the data portion sets the MCS level according to the channel situation. In this case, the lower the MCS level, the more robust the transmission and the lower the transmission rate. Thus, a signal field with a low MCS level may be received, but a data portion with a high MCS level may be received in a broken state.

In general, when a transmission failure occurs, the received frame may be discarded because the information in the frame is unreliable. However, even in this case, when the signal field is completely received, it is possible to proceed with communication by indicating the arc and the Nak during the speed frame exchange process.

13 is a conceptual diagram illustrating a data retransmission method when a data frame transmission fails according to an embodiment of the present invention.

Hereinafter, for convenience of description of an embodiment of the present invention, it is assumed that the SfeACK bit of the signal field (SIG field) is 1, which means ACK, and when the 1 bit of the retransmission indication bit is 1, the data is retransmission. It is assumed to mean a frame.

Referring to FIG. 13, the access point transmits a first downlink data frame DL1 set to more data bit 1, SfeACK bit 0, and retransmission indication (RTI) bit 0 to the terminal.

Here, the access point sets the more data bit to 1 because there is an additional data frame to transmit, and sets the SfeACK bit to 0 since there is nothing to transmit to the arc since there is no frame previously received from the terminal. In addition, since the first downlink data frame DL1 is not a retransmitted data frame, the access point sets the retransmission indication (RTI) bit to zero.

The terminal may receive the first downlink data frame DL1 from the access point and transmit the first uplink data frame UL1 to the access point after a preset time (eg, SIFS).

In more detail, the terminal may transmit the first uplink data frame UL1 having the more data bit 1, the SfeACK bit 1, and the retransmission indication bit to 0 to the access point.

Here, the terminal sets the more data bit to 1 because there is an additional data frame to transmit, and sets the SfeACK bit to 1 since the UE successfully received the first downlink data frame DL1 received from the access point. Also, since the first uplink data frame UL1 is not a data frame to be retransmitted, the terminal sets the retransmission indication (RTI) bit to zero.

Thereafter, the access point receives the first uplink data frame UL1, and after a preset time, the second downlink data frame DL2 in which the gathered data bit is set to 1, the SfeACK bit is set to 1, and the retransmission instruction bit is set to 0. ) To the terminal.

When the second downlink data frame DL2 is received from the access point, the terminal transmits the second uplink data frame UL2 having the more data bit to 1, the SfeACK to 1, and the retransmission instruction bit to 0, to the access point. do.

The access point successfully receives a signal field (SIG field) of the second uplink data frame UL2 from the terminal, but fails to receive the data frame.

Thereafter, the access point selects a third downlink data frame in which the gathered data bit is set to 1, the SfeACK is set to 0, and the retransmission indication bit is set to 0, after a preset time from when the transmission of the second uplink data frame UL2 ends. Send to the terminal.

Here, the access point can know the transmission time of the second uplink data frame UL2 through the received signal field information (for example, MCS level and length), and within the second uplink data frame UL2. Since SfeACK is 1, it can be seen that the second downlink data frame DL2 has been successfully transmitted.

In one embodiment of the present invention, the access point responds to the feedback that the transmission of the second uplink data frame has failed through the third downlink data frame, but in another embodiment of the present invention, in addition to the third downlink data frame, It may also respond through a Null Data Packet (NDP).

The terminal may retransmit, to the access point, a second uplink data frame in which the more data bit is set to 0, the SfeACK bit is 1, and the retransmission instruction bit is set to 1 based on the third downlink data frame received from the access point.

Here, the UE may retransmit the second uplink data frame to the access point because it may confirm that transmission of the second uplink data frame has failed through SfeACK in the third downlink data frame.

Since the access point knows that the second uplink data frame UL2 is a retransmitted data frame through the retransmission indication bit of 1, the access point may perform chase combining on the second uplink data frame. have.

If there is a third uplink data frame UL3 to be additionally transmitted by the terminal, the terminal first transmits the third uplink data frame having the retransmission indication bit set to 0 to the access point instead of retransmitting the second uplink data frame. You can also send. Subsequently, when retransmitting the second uplink data frame, the retransmission indication bit may be set to 1 to transmit the data frame.

Here, when ordering the third uplink data frame to the second uplink data frame, each uplink data frame may be aligned.

Referring back to FIG. 13, when a second uplink data frame UL2 that is retransmitted from the terminal is received, the access point may set the data bit to 0, the SFeACK to 1, and the retransmission instruction bit to 0 after a preset time. 4 transmits a downlink data frame to the terminal.

The terminal successfully receives the signal field of the fourth downlink data frame DL4 from the access point, but fails to receive the data frame.

In this case, the UE accesses a null data packet (NDP) in which more data bits are set to 1, SfeACK is set to 0, and a retransmission instruction bit is set to 0 after a predetermined time from the end of transmission of the fourth downlink data frame DL4. To send.

Here, the terminal may transmit an Ack frame in which SfeACK is set to 0 instead of the null data packet to the access point.

The access point may determine that the SfeACK bit in the null data packet (NDP) is 0, and may retransmit the fourth downlink data frame in which the more data bit is set to 0, the SfeACK bit is set to 1, and the retransmission instruction bit is set to 1. have.

Here, by setting the retransmission indication bit to 1, the terminal may perform chace combining.

If there is a fifth downlink data frame DL5 to be additionally transmitted by the access point, the access point does not retransmit the fourth downlink data frame DL4, but instead of retransmitting the fourth downlink data frame DL4, the fifth downlink data frame in which the retransmission indication bit is set to 0. DL5 may first be transmitted to the terminal. Subsequently, when retransmitting the fourth downlink data frame DL4, the retransmission indication bit may be set to 1 to transmit the data frame.

Referring back to FIG. 13, the terminal finally transmits the Ack frame in which the more data bit is set to 0 and the SfeACK bit is set to 1, which means that the fourth downlink data frame DL4 has been successfully received.

According to the high-speed frame exchange method according to an embodiment of the present invention, even if a data transmission failure in the high-speed frame exchange process can be responded to the acknowledgment or Nakke without interruption, the data retransmission process in the high-speed frame exchange process It is possible to exchange data efficiently. In addition, it is possible to perform robust transmission by notifying the receiver whether the data frame is a retransmission through the retransmission indication bit.

14 is a conceptual diagram illustrating a data retransmission method performed by a terminal when a data frame transmission fails according to an embodiment of the present invention.

Hereinafter, for convenience of description of an embodiment of the present invention, it is assumed that the SfeACK bit of the signal field (SIG field) is 1, which means ACK, and when the 1 bit of the retransmission indication bit is 1, the data is retransmission. It is assumed to mean a frame.

Referring to FIG. 14, if it is determined that the reception of the first downlink data frame DL1 has failed from the access point (S1410), the terminal may not receive the first signal field included in the first downlink data frame DL1. It is determined whether or not it succeeds (S1420).

When the UE determines that the first signal field is received through step 1420, the UE sets the SfeACK bit indicating 0 to the failure of the first downlink data frame to 0 based on the received first signal field and sets the RTI bit indicating whether to retransmit. It is set (S1430).

The terminal transmits the first uplink data frame including the SfeACK bit and the RTI bit set through step 1430 to the access point (S1440).

Thereafter, the terminal receives a second downlink data frame from the access point (S1450).

The terminal determines whether the second downlink data frame is the same as the first downlink data frame based on the retransmission indication bit of the signal field included in the second downlink data frame (S1460).

Here, when the retransmission indication bit is 1, the terminal determines that the second downlink data frame and the first downlink data frame are the same; when the retransmission indication bit is 0, the second downlink data frame and the first downlink data frame You can judge this as something else.

If it is determined in step 1460 that the second downlink data frame and the first downlink data frame are the same, the UE may perform chace combining on the second downlink data frame and the first downlink data frame (S1470). ).

15 is a conceptual diagram illustrating that the high speed frame exchange is stopped when the access point and the terminal continuously fail to transmit data.

Referring to FIG. 15, the second uplink data frame UL2 and the third downlink data frame DL3 have successfully transmitted a signal field (SIG field) but failed to transmit a DATA frame.

As described above, if the AP and the UE fail to transmit data frames continuously, the fast frame exchange may be stopped.

Here, if the channel exhibits a deep fading characteristic due to the characteristics of wireless communication, an error may occur even if the data frame is continuously transmitted. Therefore, the access point and the terminal may stop the high-speed frame exchange when the data frame transmission fails continuously.

Alternatively, as described above, when the AP and the UE continuously fail to transmit the data frame, the data frame may be transmitted by lowering the transmission rate of the data frame. For example, the terminal may transmit a second uplink data frame UL2 at a low transmission rate after receiving the third downlink data frame DL3 from the access point, and may transmit the same transmission rate. You can also keep sending data frames.

16 is a conceptual diagram illustrating that high-speed frame exchange is stopped when two consecutive transmissions of a terminal fail.

Referring to FIG. 16, the access point successfully transmits both a signal field (SIG field) and a data frame, but the UE indicates that the second uplink data frame (UL2) transmission has failed twice in succession.

In this case, the terminal may stop the high-speed frame exchange when the transmission of two (or more) data frames in a row fails. In this case, since the channel is deep faded and an error is more likely to occur even if the data frame is no longer transmitted due to the characteristics of the wireless communication, if the transmission of the data frame of the terminal (or access point) fails continuously, the fast frame exchange is performed. You can stop.

Alternatively, if the terminal fails to transmit two (or more) data frames consecutively, the terminal may transmit the data frame by lowering the transmission rate of the data frame without interrupting the fast frame exchange. For example, when the terminal fails to transmit the second uplink data frame twice in a row, the terminal may transmit the second uplink data frame to the access point using a low transmission rate.

In addition to FIGS. 15 and 16, there may be a case where transmission fails for both the SIG field and the data frame.

The terminal or the access point may stop the high speed frame exchange when both the signal field and the data frame fail to transmit.

In this case, the interruption of the fast frame exchange may be determined by the terminal or the access point by itself. That is, it is not necessary to perform the method described with reference to FIGS. 15 and 16, and as long as information of SfeACK (successful transmission for the previous frame) is continuously transmitted through the signal field of the data frame, continuous transmission may be possible. .

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (22)

In the method performed in the terminal, Receiving a first downlink data frame comprising a specific field that sets a bit value requesting to respond with a data frame from the access point; And And transmitting a second uplink data frame to the access point in response to a first downlink data frame based on the bit value of the specific field. The method according to claim 1, Receiving a first downlink data frame including a specific field that sets a bit value requesting to respond with a data frame from the access point, A first downlink in which a bit value of an ACK policy field, an ACK indication field, or a response frame field (RspFrm) is set to binary 11 to request to respond with a data frame; A high speed frame exchange method comprising receiving a data frame. The method according to claim 2, The acknowledgment field, the acknowledgment field, or the response frame field, If the bit value of the Ack policy field, the Ack indication field or the response frame field is binary 00, ACK, if 01, block ACK (BA), if 10, no response and 11 High frame rate switching method characterized in that each means to respond with a data frame. The method according to claim 1, Transmitting the second uplink data frame to the access point, Setting bits of a specific field in a second uplink data frame based on more data bits in the first downlink data frame; Setting more data bits of the second uplink data frame based on whether there is data to transmit; And And transmitting the second uplink data frame to the access point. The method according to claim 4, Setting bits of a specific field of a second uplink data frame based on more data bits in the first downlink data frame, When the more data bit in the first downlink data frame is 1, the bit of the specific field in the second uplink data frame is set to 11, and when the more data bit in the first downlink data frame is 0, the first data bit is 0. 2. The method of claim 2, wherein the bit of a specific field in the uplink data frame is set to 00. The method according to claim 1, Prior to receiving a first downlink data frame including a specific field that sets a bit value requesting to respond with a data frame from the access point, And transmitting the first uplink data frame having the more data bit set to 1 to the access point. The method according to claim 6, The transmitting of the first uplink data frame in which the more data bit is set to 1 may include: A high speed frame comprising transmitting a first uplink data frame in which a bit value of a specific field in the first uplink data frame is set to binary 00 or 11 and a more data bit set to 1 to the access point. Exchange method. Receiving an acknowledgment frame with the bit value of the ACK policy field set to binary 11 from the access point; Setting a bit value of an acknowledgment field in a second uplink data frame to binary 00; Setting more data bits of the second uplink data frame based on whether there is data to be transmitted; And And transmitting the second uplink data frame to the access point. The method according to claim 8, The bit of the acknowledge policy field is When the bit value of the acknowledgment field is binary 00, it means ACK, if 01, block BA, if 10, no response, and if 11, it responds with a data frame. High speed frame exchange method. The method according to claim 8, Prior to receiving from the access point an Ack frame with the bit value of the Ack policy field set to binary 11, And transmitting the first uplink data frame in which the MoreData bit is set to 1 and the bit value of the Ack policy field is set to binary 00, to the access point. Frame exchange method. Receiving a first downlink data frame from which an MoreData bit is set to 1 and a bit value of an ACK policy field is set to binary 11; Determining whether a second uplink data frame can be transmitted in response to the first downlink data frame; Setting a bit of a response frame field included in the second uplink data frame based on the determination result; Setting more data bits of the second uplink data frame based on whether there is data to be transmitted; And And transmitting the second uplink data frame to the access point. The method according to claim 11, The bit of the acknowledge policy field is When the bit value of the acknowledgment field is binary 00, it means ACK, if 01, block BA, if 10, no response, and if 11, it responds with a data frame. High speed frame exchange method. The method according to claim 11, Prior to receiving from the access point a first downlink data frame in which more data bits are set to 1 and the bit value of the acknowledgment field is set to binary 11, And transmitting the first uplink data frame having the more data bit set to 1 to the access point. The method according to claim 11, Determining whether the second uplink data frame can be transmitted in response to the first downlink data frame, And determining whether the second uplink data frame can be transmitted based on a preset frame transmission / reception time limit. In the frame exchange method performed in the terminal, Failing to receive a first downlink data frame from the access point; Determining whether reception of a first downlink field in the first downlink data frame is successful; And And if the reception of the first downlink field is successful, transmitting a second uplink data frame to the access point based on the first downlink field. The method according to claim 15, The first downward field, A 1-bit acknowledgment bit indicating whether the terminal receives the first uplink data frame transmitted before the second uplink data frame and a 1-bit retransmission indication bit indicating whether the first downlink data frame is retransmitted It is a first downlink signal field (SIG field) is set to the high speed frame exchange method. The method according to claim 15, The second uplink data frame, A first uplink signal field (SIG field) in which a 1-bit acknowledgment bit indicating that the reception of the first downlink data frame has failed and a 1-bit retransmission indication bit indicating that the currently transmitted data frame is not retransmitted High speed frame exchange method comprising a. The method according to claim 17, After transmitting the second uplink data frame to the access point, Receiving a second downlink data frame from the access point; And If it is determined that the second downlink data frame is a retransmission frame of the first downlink data frame based on a retransmission indication bit of the second downfield included in the second downlink data frame, the first downlink data frame And performing chase combining on the second downlink data frame. In the frame exchange method performed in the terminal, Receiving a first downlink data frame from the access point; And And transmitting a second uplink data frame to the access point based on a first downfield in the first downlink data frame. The method according to claim 19, The first downward field, A 1-bit acknowledgment bit indicating whether the terminal receives the first uplink data frame transmitted before the second uplink data frame and a 1-bit retransmission indication bit indicating whether the first downlink data frame is retransmitted It is a first downlink signal field (SIG field) is set to the high speed frame exchange method. The method of claim 20, When the 1-bit Ack bit indicates that reception of the first uplink data frame transmitted before the second uplink data frame has failed, the second uplink data frame that is identical to the first uplink data frame is received. High speed frame exchange method characterized in that the transmission. The method according to claim 21, The second uplink data frame, And a second uplink signal field (SIG field) in which a 1-bit Ack bit indicating successful reception of the first downlink data frame and a 1-bit retransmission indication bit indicating that the currently transmitted data frame is to be retransmitted. High speed frame exchange method, characterized in that.

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