KR100679041B1 - Method and apparatus for transmitting/receiving data with down compatibility in high throughput wireless network - Google Patents

Abstract

The present invention relates to a method and apparatus for transmitting data in a downlink compatibility in a high speed wireless network.

In a high speed wireless network, a method for transmitting data and providing downlink compatibility includes connecting to a wireless network, receiving first data according to a channel bonding scheme transmitted by a first station connected to the wireless network, and transmitting the data. Transmitting second data on each channel used for bonding, wherein the second data is a CTS frame or an RTS frame.

WLAN, Wireless Network, 802.11n, HT Data, Virtual Carrier Sensing, Control Frame

Description

Method and apparatus for transmitting / receiving data with down compatibility in high throughput wireless network

1 is a configuration of a PPDU conforming to the conventional 802.11 protocol.

FIG. 2 is a diagram illustrating a case in which stations having various transmission capacities coexist in a network and a station having low transmission capacities fails to perform virtual carrier sensing.

3 is an exemplary diagram of transmitting a response frame in a legacy method according to an embodiment of the present invention.

4 is an exemplary view illustrating a structure of a PPDU transmitted and received by an HT station according to an embodiment of the present invention.

5 is an exemplary diagram in which a receiving side transmits a legacy response frame when the transmitting side transmits HT data using channel bonding according to an embodiment of the present invention.

6 is an exemplary diagram in which a receiving side transmits a legacy response frame when the transmitting side transmits HT data using channel bonding according to another embodiment of the present invention.

7 is an exemplary diagram in which a receiving side transmits a legacy response frame when the transmitting side transmits HT data without using channel bonding.

8 is a configuration diagram of an HT station for transmitting legacy type data according to an embodiment of the present invention.

9 is a flowchart illustrating a process in which a HT station receives a HT frame and transmits a legacy frame in response thereto according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

30: Legacy Data 40: HT Data

101, 102, 103: HT station 201: legacy station

160: legacy transmission control unit

TECHNICAL FIELD The present invention relates to a wireless network, and more particularly, to a method and apparatus for providing data and providing backward compatibility in a high speed wireless network.

Recently, due to the spread of the Internet and the rapid increase of multimedia data, the demand for high speed communication network is increasing. Among them, a LAN (Local Area Network) is introduced since the late 1980s, and a high-speed Ethernet of 100 Mbps is now generally used. Recently, research on Gigabit Ethernet has been actively conducted. On the other hand, attempts to communicate by connecting to a network without wires have promoted the research and development of wireless local area networks (WLANs). As a result, the spread of WLANs has been gradually spreading in recent years. have. WLANs have poor performance in terms of data rate and reliability compared to wired LANs, but have the advantages of being able to construct a network without wires and having good mobility. As a result, the WLAN market is growing.

Due to the demand for increased data transmission and the development of wireless transmission technology, the standard of 802.11a, 802.11b, 802.11g, 802.11n, etc. has been confirmed by standardization meeting or improved by improving the IEEE 802.11 standard which is initial 1-2Mbps. . In particular, 802.11a, which has a transmission rate of 6-54 Mbps in the 5 GHz band of the NII band, uses orthogonal frequency division multiplexing (hereinafter, referred to as OFDM) as a transmission technology. Increasing interest is gaining attention over other wireless LAN standards.

Recently, KT (KT corp.) Has commercialized and is using a wireless Internet service using a WLAN called Nespot. NetSpot is a service that allows you to use the Internet using a WLAN according to the IEEE 802.11b or Wi-Fi standard. Standardization for wireless data communication systems is currently being completed or under study, including Wide Code Division Multiple Access (WCDMA), IEEE 802.11x, Bluetooth, and IEEE 802.15.3, also referred to as 3G (3G) communications. Among them, the most widely used standard for wireless data communication at a low price is IEEE 802.11b, which belongs to IEEE 802.11x. The WLAN, which meets the IEEE 802.11b standard, uses the Industrial, Scientific, and Medical (ISM) band, which can transmit data at a maximum data rate of 11 Mbps and can be used without permission in the 2.4 Ghz band, or under a constant electric field. Recently, WLANs using IEEE 802.11a, which can transmit data of up to 54 Mbps using the OFDM scheme in the 5 Ghz band, are increasing.

Both Ethernet and WLAN, which are generally used today, use carrier sensing multiple access (hereinafter referred to as CSMA). The CSMA method refers to a method of checking whether a channel is used and transmitting the channel if it is not in use (idle), and if not, attempting transmission again after a certain time. Currently, the CSMA / CD (Carrier Sensing Multiple Access with Collision Detection) method which is an improvement of the CSMA method is used in wired LAN, and the CSMA / CA (Carrier Sensing Multiple Access with Collision Avoidance) method is used for packet data wireless data communication. In the CSMA / CD mode, the station stops signal transmission when it detects a collision in the middle of signal transmission. If the CSMA / CA scheme monitors the use of the channel before transmission, in the CSMA / CD scheme, the station monitors whether a signal collides on the channel during transmission. In CSMA / CD, when a collision is detected during transmission of a signal, the station stops transmission and transmits a jam signal to another station to inform the fact of the collision. After transmitting the jam signal, the station transmits the signal again after a random back off. In the CSMA / CA method, even when the channel becomes empty, the station does not transmit data immediately but waits for a certain time, and then randomly backs off and transmits a signal to avoid a signal collision. If there is a collision of the signal being transmitted, the probability of collision is further lowered by increasing the random backoff time by 2 times.

In CSMA / CA, information about the time occupied by the network in physical carrier sensing and the MAC Protocol Data Unit / PHY Service Data Unit (MPDU / PSDU) is set so that the network is not used during that time. There is a virtual carrier sensing (Virtual Carrier Sensing) scheme. However, when the MPDU / PSDU cannot be interpreted, the virtual carrier sensing method cannot be applied.

802.11n covers 802.11a of 2.4GHz and 802.11b, g of 5GHz, and stations with various performances coexist. However, in order for these various stations to operate in the CSMA / CA method, MPDUs / PSDUs must be interpreted. However, there are cases where a low-speed station cannot process data transmitted and received at high speed. In this case, the low speed station will not be able to perform virtual carrier sensing.

1 is a configuration of a PPDU (PLCP Protocol data unit) according to the conventional 802.11 protocol. The PPDU includes a Physical Layer Convergence Procedure (PLCP) header and a PSDU. By using the data rate field 3 and the data length field 4 of the PLCP header of the PPDU, it is possible to calculate the length of the data field that follows. Since this value knows how much time it takes to transmit and receive data, virtual carrier sensing can be performed. In addition, if the MPDU can be extracted accurately from the received PPDU, the "Dur / ID" field, which is one of the header fields of the MPDU, is interpreted to assume that the medium is busy during the intended use time of the medium. do. Preamble and signal fields of the received PPDU frame have been interpreted, but if an error occurs, the MAC takes time off of the extended InterFrame Space (EIFS) instead of DIFS (DCF InterFrame Space) and participates in the backoff. . This does not guarantee fairness in media access of all stations pursuing the Distributed Coordination Function (DCF).

Therefore, when a transmission capacity is improved in a network including a station (legacy station, a station using an existing protocol) that does not have improved transmission capability, and a high throughput (HT) station transmitting and receiving data is transmitted and received, As a result of failing to interpret the Dur / ID field in the data transmitted / received by the HT station, virtual carrier sensing cannot be performed.

FIG. 2 is a diagram illustrating a case in which stations having various transmission capacities coexist in a network and a station having low transmission capacities fails to perform virtual carrier sensing.

The HT STA 101 is a high throughput station complying with the 802.11n protocol and is a station operating in a channel bonding or multiple input multiple output (MIMO) scheme, and refers to a station having a high data throughput. Channel bonding means transmitting data on two or more channels. When a transmitting station transmits data, it selects a channel adjacent to its current channel and binds two channels to extend a channel. MIMO is an adaptive array antenna technology that uses a plurality of antennas to electrically control the directivity. The MIMO narrows the directivity onto the beam to form multiple independent transmission paths and multiplies the transmission speed by the number of antennas. However, when data is transmitted / received through channel bonding or MIMO, stations suitable for such a transmission scheme, that is, transmission capability may read data transmitted and received, but stations (legacy stations) that do not read data. Physical carrier sensing can detect whether the reception power is above a certain value in the physical layer and can tell the MAC layer whether the medium is busy or idle, so it is not necessary to interpret data transmitted and received.

When the transmitting side HT STA 101 transmits the high speed data (HT Data), the receiving side 102 sends a response indicating that the data has been received as the high speed data (HT Ack). At this time, since the other HT STA 103 can interpret the high speed data (HT Data, HT Ack), the medium is considered to be in use by setting NAV (Network Allocation Vector) for the period during which the HT data and the HT Ack are transmitted and received. Then, when the NAV period ends, data can be transmitted by occupying the medium through the backoff after the DIFS period passes.

On the other hand, the legacy station 201 is a station following protocols such as 802.11a, 802.11b, and 802.11g. Since the HT data cannot be interpreted, the legacy station 201 waits for the EIFS period after checking that the HT Ack is terminated through physical sensing. Take part in the off. Therefore, since the medium can be allocated by waiting for a relatively longer time than other high speed stations 101, 102, and 103, the efficiency can be low.

On the other hand, in the 802.11 standard, control response frames such as ACK or Clear to Send (CTS) are the highest of the BSS Basic Rate Sets if they cannot be sent at the same data rate or at the same data rate as the previous frame. HT frames, unlike legacy, have HT preambles and HT signals added. In addition, the overhead of the PPDU frame due to the additional HT signal field is increased, so that in the case of a small frame such as ACK, the efficiency is lower than the legacy PPDU. The legacy PPDU header is 20 us (802.11a) for 802.11a, whereas the newly defined HT PPDU header is over 40us.

Therefore, when a low speed legacy station cannot interpret data transmitted by a high speed HT station, it prevents the virtual carrier sensing from becoming impossible and when a small data such as a response frame is sent at high speed, the network is transmitted without the HT preamble. There is a need for ways to increase efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the present invention provides a method and apparatus for a station having a low transmission capability to perform a virtual carrier when a station having different transmission capabilities coexists in a wireless network. There is a purpose.

Another object of the present invention is to improve efficiency by transmitting in a low transmission scheme when the length of data to be transmitted is short.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

TECHNICAL FIELD The present invention relates to a wireless network, and more particularly, to a method and apparatus for providing data and providing backward compatibility in a high speed wireless network.

In the high-speed wireless network according to an embodiment of the present invention, a method for transmitting data and providing backward compatibility includes connecting to a wireless network, and first data according to a channel bonding scheme transmitted by a first station connected to the wireless network. And receiving second data on each channel used for channel bonding, wherein the second data is a CTS frame or an RTS frame.

In the high-speed wireless network according to an embodiment of the present invention, the apparatus for providing downlink compatibility and transmitting data receives first data according to a channel bonding scheme transmitted by a first station connected to the wireless network by accessing the wireless network. And a transmitter for transmitting second data to each channel used for the channel bonding, wherein the second data is a CTS frame or an RTS frame.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, the present invention will be described with reference to a block diagram or a flowchart illustrating a method and apparatus for transmitting and receiving legacy data in a high-speed wireless network according to embodiments of the present invention. At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to produce a computer or other programmable data. Instructions for performing data processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

A wireless network capable of transmitting and receiving HT data or high speed data, such as 802.11n, is called a high speed wireless network. In addition, an embodiment of the high-speed wireless network follows the protocol of 802.11n, and means a wireless network that is compatible with legacy 802.11a, 802.11b, and 802.11g.

3 is an exemplary diagram of transmitting a response frame in a legacy method according to an embodiment of the present invention. HT stations 101, 102, 103 and legacy stations 201 coexist in a wireless network. In step S10, the transmitting side HT station 101 transmits the HT data to the receiving side HT station 102. As described above, the HT data refers to data to be transmitted at high speed by using a channel bonding or MIMO scheme. High Throughput (HT) stations include stations that conform to protocols that enable high speed data transmission, such as 802.11n. The receiving HT station 102 and the other HT stations 103 can interpret the HT data and thus perform virtual carrier sensing. At this time, the legacy station 201 cannot interpret the HT data and thus cannot perform virtual carrier sensing. However, physical carrier sensing may be performed by determining that the medium is currently in use. In this case, if the transmission of the HT data is terminated and enters the step S11, the user can wait for the EIFS period and then perform backoff.

When the transmitting side HT station 101 completes the transmission of the HT data, step S11 is performed. At this time, the receiving side HT station transmits a legacy response frame after the SIFS period. The legacy response frame means a response frame generated according to protocols such as 802.11a, 802.11b, and 802.11g. The legacy response frame is a frame that can be transmitted and received by both the legacy station and the HT station. The HT stations 101, 102, and 103 that have received the legacy response frame all interpret the legacy response frame and when the legacy response frame ends, enter the step S12 and participate in the backoff after the DIFS period.

In addition, the legacy station can also interpret the legacy response frame, so instead of the EIFS starting from the previous step S11, when the legacy response frame ends, i.e., after the DIFS period is entered again after entering the step S12, the back-off is the same as the HT station. Take part Therefore, as the legacy station described in FIG. 2 does not interpret the HT data, it is possible to prevent the case of participating in the backoff after waiting for EIFS at step S12. As a result, legacy stations can evenly participate in the backoff and do not cause performance degradation.

4 is an exemplary view illustrating a structure of a PPDU transmitted and received by an HT station according to an embodiment of the present invention.

The HT station can transmit and receive data in two ways. Both approaches begin with legacy preamble, so that legacy stations can also be understood.

The legacy PPCP (PLCP Protocol data unit) 30 includes a Legacy Short Training Field (L-STF), a Legacy Loing Training Field (L-LTF), a Legacy Signal Field (L-SIG) and a data payload. L-SIG is composed of data rate, reserved bit, length, parity, and tail bit as shown in Fig. 1. Legacy PPDU has data payload after L-STF, L-LTF, and L-SIG. The L-STF, L-LTF, and L-SIG contain power management and signal information, and legacy data is added after the legacy preamble, so that the legacy frame 30 can be interpreted by both the HT station and the legacy station. Do.

On the other hand, if the HT preamble is added after the legacy preamble, the HT station recognizes that the received PPDU 40 is HT data. The HT preamble includes information on HT data. The HT preamble consists of HT-SIG, HT-STF, and HT-LTF. The HT-SIG includes the length of the HT data, MCS information (MCS) defined for modulation and coding, bits indicating advanced coding, and whether transmission is performed by all antennas. Sounding packet to indicate the number of HT-LTFs in the transmitted PPDU (Number of HT-LTF), whether or not to apply a Short Guard Interval to the data area of the frame (Short GI), scrambler ( ScramblerINIT), information on whether the PPDU is signaled in the 20 MHz or 40 MHz band (20/40 BW), and a CRC field for error checking. HT data is added after the HT-SIG, HT-STF, and the number of HT-LTFs specified by the HT-SIG including this information.

As shown in FIG. 4, when short data is inserted into the HT PPDU 40 and transmitted, the overhead occurs because of more HT preambles than actual data to be transmitted. Therefore, when only short information such as a control frame is included, it is efficient to use the legacy PPDU 30. The legacy PPDU 30 also enables virtual carrier sensing of the legacy station when the legacy station is present in the wireless network.

5 is an exemplary diagram in which a receiving side transmits a legacy response frame when the transmitting side transmits HT data using channel bonding according to an embodiment of the present invention. When the transmitting side selects a channel immediately above or immediately below and adjacent to the current channel to bundle two channels and transmits the two channels, the receiving side transmits legacy response frames on both channels. 5 is an exemplary diagram when each antenna cannot handle a different channel. The receiving HT station uses a superposition mode that overlaps the data including the legacy response frame 30 from the lower subchannel to the upper subchannel through a single antenna 181.

In this case, the legacy response frame 30 may be transmitted through the upper and lower subchannels, and the HT stations and the legacy stations existing in the upper and lower subchannels may receive the legacy response frame 30. The PPDU including the legacy response frame includes a Legacy Short Training Field (L-STF), a Legacy Loing Training Field (L-LTF), a Legacy Signal Field (L-SIG), and a data payload. The PPDU including the legacy response frame has been described above with reference to FIG. 4.

6 is an exemplary diagram in which a receiving side transmits a legacy response frame when the transmitting side transmits HT data using channel bonding according to another embodiment of the present invention. Unlike FIG. 5, each of the antennas 181 and 182 transmits data through different channels. When the transmitting side selects a channel immediately above or immediately below the current channel and binds the two channels, the receiving side transmits legacy response frames on both channels. Unlike FIG. 5, the antennas 181 and 182 are capable of handling different channels. The receiving side accesses the lower subchannel and the upper subchannel using the respective antennas 181 and 182 to transmit the same legacy response frame 300. The configuration of the frame according to the legacy format is as described with reference to FIG.

By sending legacy data to both the control channel and the extension channel at the same time in response to the frame sent using the channel bonding of FIGS. 5 and 6, the station existing in the extension channel is also transmitted. Allow data to be received.

7 is an exemplary diagram in which a receiving side transmits a legacy response frame when the transmitting side transmits HT data without using channel bonding. When the transmitting side transmits the HT data using MIMO technology, the receiving side selects one antenna 181 to send a response frame that follows the legacy format in the current channel. The transmitting side may receive a response frame of a legacy format received through the corresponding channel, and other HT stations may also perform the virtual carrier sensing by interpreting the legacy response frame. In addition, legacy stations in the channel can also interpret legacy response frames. The structure of the frame according to the legacy format is as described with reference to FIG. 4.

5 to 7, the receiving side HT station has been described in various ways to transmit the legacy PPDU according to the transmission method of the transmitting side HT station. In order for the receiving HT station to know the transmission method of the transmitting HT station, the receiving HT station may look at the MCS value in the HT-SIG of the HT PPDU described with reference to FIG. 4. The number of antennas or the number of spatial streams used for data transmission, the modulation scheme used, the coding rate, the guard interval, and the guard interval, according to the MCS values shown in Table 1. It is possible to know whether the channel is bonded (40 MHz mode). Table 1 is an example of the MCS table.

MCS Number of streams Modulation method Coding rate GI = 800 ns GI = 400 ns 20 MHz 40 MHz 20 MHz 40 MHz 0 One BPSK 1/2 6.50 13.50 7.22 15.00 One One QPSK 1/2 13.00 27.00 14.44 30.00 2 One QPSK 3/4 19.50 40.50 21.67 45.00 3 One 16-QAM 1/2 26.00 54.00 28.89 60.00 4 One 16-QAM 3/4 39.00 81.00 43.33 90.00 5 One 64-QAM 2/3 52.00 108.00 57.78 120.00 6 One 64-QAM 3/4 58.50 121.50 65.00 135.00 7 One 64-QAM 5/6 65.00 135.00 72.22 150.00 8 2 BPSK 1/2 13.00 27.00 14.44 30.00 9 2 QPSK 1/2 26.00 54.00 28.89 60.00 10 2 QPSK 3/4 39.00 81.00 43.33 90.00 11 2 16-QAM 1/2 52.00 108.00 57.78 120.00 12 2 16-QAM 3/4 78.00 162.00 86.67 180.00 13 2 64-QAM 2/3 104.52 216.00 116.13 240.00 14 2 64-QAM 3/4 117.00 243.00 130.00 270.00 15 2 64-QAM 5/6 130.00 270.00 144.44 300.00 16 3 BPSK 1/2 19.50 40.50 21.67 45.00

In addition to the response frame, the HT station may transmit a PPDU of a control frame including short information such as a clear-to-end (CTS) frame and a ready-to-end (RTS) frame in a legacy manner. When transmitting in the legacy manner, the legacy station may perform virtual carrier sensing. Since the legacy method does not need to add the HT preamble, overhead can be reduced when transmitting a small amount of data. When a large amount of data is transmitted, a HT type PPDU is transmitted, and a small amount of data such as a control frame transmits a legacy type PPDU, thereby reducing the amount of total network transmission / reception data and implementing a wireless network coexisting with a legacy station. have.

As used herein, the term 'unit', that is, 'module' or 'table' or the like, refers to a hardware component such as software, a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC). The module performs some functions. However, modules are not meant to be limited to software or hardware. The module may be configured to be in an addressable storage medium and may be configured to play one or more processors. Thus, as an example, a module may include components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, subroutines. , Segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and modules may be combined into a smaller number of components and modules or further separated into additional components and modules. In addition, the components and modules may be implemented to reproduce one or more CPUs in a device.

8 is a configuration diagram of an HT station for transmitting legacy type data according to an embodiment of the present invention. The HT station 100 is largely composed of a transmitter 110, a receiver 120, an encoder 130, a decoder 140, a controller 150, a legacy transmission controller 160, and an antenna 181, 182. do. The antennas 181 and 182 function to send and receive wireless signals.

The transmitter 110 transmits a signal to the antennas 181 and 182, and the encoder 130 encodes data to make a signal to be transmitted by the transmitter 110. In order to transmit a signal through two or more antennas in the MIMO method, it is necessary to divide and encode data. In addition, in order to transmit a signal through a channel bonding method, the transmitter selects a channel immediately above or just below the current channel, binds two channels, and transmits the signal.

The receiving unit 120 receives a signal from the antennas 181 and 182, and the decoding unit 140 decodes the signal into data. Data received in the MIMO method requires a process of integrating these data. Data received using the channel bonding method requires a process of integrating data of two channels.

The legacy transmission control unit 160 controls to transmit in a legacy manner when data of short length such as an ACK frame, a CTS frame, or an RTS frame is transmitted. The controller 150 is responsible for information exchange and control between the components.

9 is a flowchart illustrating a process in which a HT station receives a HT frame and transmits a legacy frame in response thereto according to an embodiment of the present invention.

The wireless network is connected (S301). In this case, it does not necessarily mean connecting to the created wireless network, but also includes generating a wireless network. For example, a process of generating a basic service set (BSS) such as an access point (AP) includes this. Then, the first station existing in the network receives the first data transmitted by the first protocol (S302). As described above, the first protocol means a protocol that is transmitted and received in a high speed manner such as 802.11n. In addition, it means a protocol having backward compatibility with the legacy protocol.

Downward compatibility means that a protocol or software that provides better performance or better functionality is compatible with a previously presented protocol or software. For example, 802.11n may interpret data transmitted and received in 802.11a, 802.11b, and 802.11g, and may transmit and receive data at high speed. In addition to the protocol, as the software is upgraded, the ability to interpret or manage the data generated by the existing version is called backward compatibility.

After reception, it is checked whether the first data is transmitted by the channel bonding method (S310). When transmitted by the channel bonding method, second data according to the second protocol is transmitted to the first station in each channel used for channel bonding (S320). The second protocol means sending a frame that can be interpreted by a legacy station existing in each channel during channel bonding. Therefore, when the first protocol is based on the 802.11n scheme, the second protocol includes protocols such that 802.11n guarantees backward compatibility, such as 802.11a, 802.11b, and 802.11g. The sending method has been described with reference to FIGS. 5 and 6.

On the other hand, if it is not transmitted by the channel bonding method in step S310, for example, when transmitted in the same manner as MIMO, the second data according to the second protocol is transmitted to the channel where the first data is received (S330). The transmission process is described with reference to FIG. 7. As described above, the second protocol includes a protocol for ensuring that the first protocol is backward compatible.

The wireless network of FIG. 9 may be a BSS in which an AP exists or an independent basic service set (BSS) in which an AP does not exist. In addition, the second data is short-length data and includes control frames such as ACK and CTS.

The second data is data that can be interpreted by the legacy station so that the legacy station can also sense virtual carriers. In addition, in the case of a wireless network that does not include a legacy station, the transmission efficiency may be increased by using the second data.

Those skilled in the art will appreciate that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

By implementing the present invention, when stations with different transmission capabilities coexist in a wireless network, stations with low transmission capabilities may perform a virtual carrier.

By implementing the present invention, efficiency can be improved when the length of data to be transmitted is short.

Claims (8)

Transmitting, by a first station connected to a wireless network capable of transmitting and receiving data, first data according to channel bonding; And Receiving, by the first station, second data transmitted on the channel used for the channel bonding, And the second data is a CTS frame or an RTS frame. The method of claim 1, The wireless network is based on 802.11n, the first data is data based on 802.11n, the second data is data based on any one of 802.11a, 802.11b, 802.11g, 802.11n , Data transmission and reception method in a wireless network. The method of claim 1, Receiving the second data comprises receiving the second data simultaneously on each channel used for the channel bonding. The method of claim 1, And the second data is legacy data. A transmitter for transmitting first data according to channel bonding; And It includes a receiving unit for receiving the second data transmitted in the channel used for the channel bonding, And the second data is a CTS frame or an RTS frame. The method of claim 5, The first data is data based on 802.11n, and the second data is data based on any one of 802.11a, 802.11b, 802.11g, and 802.11n. The method of claim 5, And the receiving unit simultaneously receives the second data in each channel used for the channel bonding. The method of claim 5, And the second data is legacy data.

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