KR100266455B1 - Wireless LAN data transmission and reception method and apparatus - Google Patents

Abstract

The present invention relates to a method and apparatus for transmitting and receiving data for a wireless LAN, wherein an interface unit interfaces with a computer, a memory stores a control program, data, and other information, and a first DM controller is used for According to the address, a control signal is output to transmit and receive the corresponding frame, and the central processing unit receives the data of the computer from the interface unit, creates a linked list of each frame and the frame according to the frame exchange sequence, and stores it in the memory. The first address of the linked list is stored in the first DM controller, and the modem modulates the data transmitted by the first DM controller in a predetermined manner and transmits the data to the wireless transmission / reception module and is received from the wireless transmission / reception module. Demodulate the first DM signal The controller transmits the signal transmitted from the modem to the controller. The wireless transmission / reception module modulates and transmits the signal output from the modem into a radio signal, converts the received radio signal into a digital signal, and the second DM controller transmits the signal received from the modem. Control to store in the memory.

Description

Wireless LAN data transmission and reception method and apparatus

The present invention relates to a method and apparatus for transmitting and receiving data for a wireless local area network (W-LAN), and more particularly, in the implementation of a medium access control (MAC) in a wireless LAN field of data communication, The present invention relates to a method and apparatus for transmitting / receiving data that reduces the time required of software for interpreting a frame, creates a frame suitable for a situation, and adjusts an accurate transmission time.

Data transmission of a WLAN is recognized as data only when the frames promised by each other are sequentially transmitted according to a frame exchange sequence.

In existing systems, the software interprets or produces every frame to keep this order. However, in the conventional LAN, not only the timing proposed by a certain protocol cannot be matched due to time loss caused by the entire frame analysis or fabrication by software, but also there is a disadvantage in that a collision between data occurs due to the failure of an accurate transmission time.

This may eventually cause a problem that the connection between the upper layers of the data communication is broken, which causes a deterioration of the overall performance and stability of the WLAN.

For example, in a conventional LAN apparatus, when a sender tries to transmit two pieces of constant data in the order of " Ready to send (RTS)-Clear to send (CTS)-DATA-ACK-DATA-ACK '' frame to a receiver, The sender creates an RTS frame, calculates the length of the entire data, puts it in the Duration field of the RTS frame, and transmits the same through a Direct Memory Access controller.

Then, the receiver compares the type of the frame being received, the result of the error check (CRC: Cyclic Redundancy Check), and whether the RA (Receiver Address) field of the frame is the same as the receiver address. Decide where you want to send it, and make a CTS frame and send it to the right person within the specified time.

These processes exist between CTS and DATA, between data and ACK, and this applies to transmission and reception between all signals.

In this process, the time until the sender receives CTS frames from the receiver to inform reception is proposed as 20μsec in the WLAN specification, but in practice, the central processing unit makes this decision within 20μsec by software. It is impossible to make it and send it to the other side.

Conventional WLAN devices require hundreds of microseconds to several milliseconds, so it is difficult to support all sequences of the basic protocol (DCF: Distributed Coordination Function), and optional point coordination function (PCF). Point Coordination Function) is hardly supported.

Hereinafter, with reference to the accompanying drawings will be described with respect to the prior art.

1 is a configuration diagram of a conventional WLAN device,

2 is a flowchart of a conventional method for transmitting a wireless LAN device.

3 is a flowchart of a method of receiving a conventional wireless LAN apparatus.

As shown in Figure 1, the configuration of a conventional wireless LAN device 102,

An interface unit 103 for interfacing with the computer 101;

A central processing unit (104) for inputting and outputting data to and from the computer (101) through the interface unit (103) and controlling wireless data communication with an external wireless LAN device according to a computer command;

A memory (105) containing a control program of the central processing unit (104);

Transmission and reception DM controllers 106 and 107 for inputting and outputting corresponding frames under the control of the central processing unit 104;

A modem 108 for modulating an output signal of the transmission DM controller 107 and demodulating a received signal;

The wireless transmission and reception module 109 modulates and outputs the wired signal output from the modem 108 into a wireless signal, and demodulates the input wireless signal into a digital signal.

The operation of the conventional WLAN device 102 by the above configuration is as follows. For reference, the initial transmission / reception portion of the operation has been described in detail, and the description of the following portion is briefly described for the operation of the repeated components for the sake of simplicity.

Transmission data from the computer 101 is input to the central processing unit 104 via the interface unit 103.

Then, the central processing unit 104 makes an ALTS frame (RTS) informing the information about the length of the data and the transmission, and makes data frames DATA1 and DATA2 from the data (S201).

The data frames DATA1 and DATA2 vary depending on the amount of data, and it is assumed here that only two are created.

Next, the central processing unit 104 stores the RTS frame (RTS) in the memory 105, and sets the address of the RTS frame to the transmission DM controller 107 (S202). In addition, the CTS frame CTS is set in the receiving DM controller 106 (S203).

Next, the central processing unit 104 controls the transmission DM controller 107 to output the RTS frame (RTS) in the memory 105 to the modem 108.

The modem 108 then modulates the RTS frame by Direct Sequence Spread Spectrum (DSSS) into a QPSK signal. Here, the modulation scheme may vary depending on the type of modem.

Next, the wireless transmission / reception module 109 modulates the signal modulated by the modem 108 to a high frequency of about 2.4 GHz and transmits it wirelessly (S204).

Then, the receiver receives the demodulated signal of the RTS frame (RTS), demodulates the data, checks the data, and transmits a radio signal modulated by the CTS frame (CTS) indicating that the reception is ready (S205).

Then, the wireless transmission / reception module 109 demodulates the 2.4 GHz radio signal into a baseband Kewpie escape signal, and the modem 108 demodulates the Kewpie escape signal into a CTS frame (CTS) and outputs it.

Next, the receiving DM controller 106 sends the CTS frame CTS to the central processing unit 104, and the central processing unit 104 performs CRC check and analysis of the frame (S206).

If the received CTS frame (CTS) is correct, the central processing unit 104 sets the data frame to the transmission DM controller 107 (S207), and sets the ack frame (ACK) to be received correspondingly. (S208).

Next, the central processing unit 104 transmits the data frame through the transmission DM controller 107, the modem 108, and the wireless transmission / reception module 109 (S209), and waits for a reception frame (S210).

Then, on the other side, when the data frame DATA1 is correctly received, the acknowledgment frame is transmitted.

Then, the Ack frame is received and decoded through the path (S211), the central processing unit 104 sets the data frame (S212), and sets the Ack frame (S213).

Next, the central processing unit 104 transmits the second data frame DATA2 and waits for a reception frame (S215).

Next, the other party correctly receives the data frame DATA2 and transmits an ack frame.

Then, the central processing unit 104 receives the acknowledgment frame (ACK) and, if correct, completes the transmission (S216).

On the other hand, the receiving process is as follows.

First, the central processing unit 104 sets the reception DM controller 106 to a reception standby state (S220) and waits for a reception frame (S221).

Next, when the ALTS frame is received from the counterpart, the CPU 104 analyzes the ALTS frame (RTS) (S222) to make a frame corresponding to the received frame. In this case, a CTS frame CTS corresponding to the RTS frame is created (S223).

Next, the central processing unit 104 sets the CTS frame CTS (S224), and sets the data frame DATA1 to be received correspondingly (S225).

Next, the central processing unit 104 transmits a CTS frame (CTS) (S226), and waits for a reception frame (S227).

Then, the counterpart receives the CTS frame CTS and transmits the data frame DATA1.

Then, the central processing unit 104 decodes the received data frame DATA1 to confirm that it is correctly received (S228), and generates an ACK frame (ACK) (S229).

Next, the central processing unit 104 sets the ack frame ACK (S230), and sets the data frame DATA2 (S231).

Next, the central processing unit 104 transmits an ACK frame (ACK) (S232), and waits for a reception frame (S233).

Then, as described above, the counterpart transmits the data frame, and the central processing unit 104 transmits the acknowledgment signal ACK and terminates the reception as described above (S234 to S237).

As described above, the conventional wireless LAN apparatus has a time loss caused by the central processing unit interpreting or manufacturing a frame necessary for all transmission / reception in software during transmission and reception, so that the timing proposed by a certain protocol cannot be matched. In addition, there is a disadvantage in that a collision between data occurs due to failure to match the exact transmission time.

Therefore, an object of the present invention is to solve the disadvantages of the prior art, and to provide a wireless LAN device and a control method thereof to enable data transmission and reception by a hardware controller to satisfy all the timings proposed by the WLAN specification. It is.

1 is a block diagram of a conventional wireless LAN device.

2 is a flowchart of a conventional method for transmitting a wireless LAN device.

3 is a flowchart of a receiving method of a conventional wireless LAN apparatus.

Figure 4 is a block diagram of a wireless LAN device according to an embodiment of the present invention.

5 is a flowchart of a method for transmitting a WLAN device according to an embodiment of the present invention.

6 is a flowchart of a receiving method of a WLAN device according to an embodiment of the present invention.

The configuration of the present invention for achieving the above object,

In a WLAN device,

The interface unit interfaces with a computer

The memory contains a control program, stores data,

The first DM controller outputs a control signal to transmit and receive the corresponding frame according to the address of the stored linked list,

The CPU receives computer data from the interface unit, creates a linked list of frames and frames according to a frame exchange sequence, stores the linked list in the memory, and stores the first address of the linked list in the first DM controller. Save to,

The modem modulates the output signal of the first DM controller in a predetermined manner, demodulates the received signal, and transmits the demodulated signal to the first DM controller.

The wireless transmission / reception module modulates and transmits the signal output from the modem into a wireless signal, converts the received wireless signal into a digital signal,

The second DM controller may control to store the signal received from the modem in the memory.

Another configuration of the present invention for achieving the above object,

Creating and setting a transmission frame and a data frame incorporating information about a length and transmission of data;

Sequentially transmitting the transmission frame and the data frame, and waiting for a processing result.

Another configuration of the present invention for achieving the above object,

Setting a receiving DM controller to receive a certain frame;

Waiting for the reception result of the received frame.

With reference to the accompanying drawings an embodiment in which this invention can be implemented by the above configuration will be described.

4 is a block diagram of a WLAN device according to an embodiment of the present invention;

5 is a flowchart illustrating a method for transmitting a WLAN device according to an embodiment of the present invention.

6 is a flowchart illustrating a receiving method of a WLAN device according to an embodiment of the present invention.

As shown in Figure 4, the configuration of a WLAN device according to an embodiment of the present invention,

An interface unit 3 for interfacing with the computer 1;

A central processing unit (4) for inputting and outputting data to and from the computer (1) through the interface unit (3) and controlling wireless data communication with an external wireless LAN device according to a computer command;

A memory (15) containing a control program of the central processing unit (4), a frame necessary for data transmission and reception, a DM linked list, a data frame, and the like;

By the control of the CPU 4, the address of a frame stored in the memory 15 is set, and a control signal is output to check the received signal and output the corresponding frame to the memory 15. A first DM controller 5;

A modem (12) for modulating an output signal of the first DM controller (5) and demodulating the received signal and transmitting the demodulated signal to the first DM controller;

A second DM controller 13 which receives a signal demodulated by the modem 12 in parallel with the first DM controller 5 and stores it in the memory 15 according to the set linked list; ;

The wireless communication module 14 modulates the signal output from the modem 12 into a wireless signal and transmits the signal, and converts the received wireless signal into a digital signal.

The first DM controller 5,

A first register part 6 which embeds a first address of a frame related to a preset reception;

A second register unit (7) for storing the first address of the linked linked list from the central processing unit (4);

The first register part 6, the second register part 7 and the check signal are input to control the corresponding frame of the memory 15 to be transmitted to the modem 12, and upon reception completion of the central processing unit ( 4) a frame controller 9 for providing a report to;

A transmission frame decoder 10 which receives the output of the frame controller 9 and decodes a frame to be received;

A reception frame decoder (11) for decoding a frame received from the modem (12);

And a checker 8 for comparing the frames of the transmission frame decoder 10 and the reception frame decoder 11 and outputting the check signal.

Referring to the operation of the wireless LAN device according to an embodiment of the present invention by the above configuration is as follows.

First, when power is applied by the user, the operation of the WLAN apparatus 2 according to the present invention is started. After the operation is started, data to be transmitted from the computer 1 is input to the central processing unit 4 via the interface unit 3.

Then, the central processing unit 4 creates an RTS frame (RTS) informing the transmission of information and the length of the data according to the frame exchange sequence, and makes the data frames DATA1 and DATA2 from the data, Create a linked data linked list in which the address is stored (S1).

The data frames DATA1 and DATA2 vary depending on the amount of data, and it is assumed here that only two are created.

Next, the central processing unit 4 stores the RTS frames RTS, the data frames DATA1 and DATA2 and the data linked list in the memory 15, and the RTS frames RTS and the data frames DATA1 and DATA2. Control the frame controller 9 of the first DM controller 5 and store it in the second register unit 7 (S2, S3).

On the other hand, in the first register unit 6, the first address of the linked list of frames to be output at the time of data reception is set in advance by the central processing unit 4.

Then, the frame controller 9 outputs a control signal to the memory 15 to output the RTS frame RTS corresponding to the first address of the linked list of the second register unit 7.

Then, the memory 15 outputs the RTS frame RTS to the modem 12 via the frame controller 9 under the control of the frame controller 9.

In this case, the transport frame decoder 10 decodes the transmitted TLS frame (RTS) to generate a CTS frame (CTS) to be received.

Then, the modem 12 spreads the RTS frame to the DSSS (Direct Sequence Spread Spectrum) band and modulates it into a QPSK signal and outputs the modulated signal. Here, the modulation scheme may vary depending on the type of modem.

Next, the wireless transmission / reception module 14 modulates the signal modulated by the modem 12 to a high frequency of about 2.4 GHz and transmits it wirelessly.

Then, the receiver receives the demodulated signal of the RTS frame (RTS), demodulates it, and transmits a CTS frame (CTS) indicating that the data is ready for reception after confirming the data.

Then, the wireless transmission / reception module 14 demodulates the 2.4 GHz radio signal into the KP escape signal, and the modem 12 demodulates the KP escape signal into the CTS frame CTS.

Next, the reception frame decoder 11 performs CRC check on the CTS frame and outputs the CRC check.

Then, the checker 8 compares the CTS frame CTS of the reception frame decoder 11 with the output CTS of the transmission frame decoder, and outputs the result to the frame controller 9.

If the received CTS frame CTS is correct, the frame controller 9 outputs a control signal to the memory to output the data frame DATA1, and the memory 15 outputs the data frame DATA1 to the modem 12 and to the memory. Transmit through the wireless transmit / receive module 14.

However, if the CTS frame is not correct in the above process, the frame controller 9 transmits the frame requesting retransmission through the modem 12 and the wireless transmission / reception module 14. There is no response depending on the communication method. Then, the other party transmits the CTS frame again.

Next, the receiver side receives the data frame DATA1 and transmits the acknowledgment frame ACK as an acknowledgment signal indicating that the data frame DATA1 has been correctly received.

Then, the Ack frame ACK is also demodulated through the wireless transmission / reception module 14 and the modem 12, and is transmitted to the reception frame decoder 11 and the checker (8).

The checker 8 compares the received ACK frame ACK with the output ACK of the transport frame decoder and transmits the result to the frame controller 9.

Then, the frame controller 9 confirms that the ACK frame ACK is correctly received, and outputs a control signal to the memory 15 to transmit the next data frame DATA2.

Then, the memory 15 transmits the data frame DATA2 to the modem 12 through the frame controller 9, and the data frame DATA2 is modulated by the modem 12 and the wireless transmission / reception module 14 and wirelessly. Is sent.

Next, the receiver side receives the data frame DATA2 and transmits the ACK frame ACK as an acknowledgment signal indicating that the data frame DATA2 has been correctly received.

Then, as in the above process, the frame controller 9 confirms that the ACK frame (ACK) is correctly received through the radio transceiver module 14, the modem 12, the reception frame decoder 11 and the checker (8).

Then, the frame controller 9 transmits the data frames DATA1 and DATA2 to the counterpart receiver's computer by the above process, so that the information on the retransmission request, the presence or absence of an error, and the information on the correct transmission of the data are displayed. The report shown is delivered to the central processing unit 4 (S4).

Then, the central processing unit 4 transmits this report through the interface unit 3 at the request of the computer 1.

The above process has been described mainly for data transmission. Hereinafter, the data reception process will be described.

First, except for data transmission, the CPU 4 sets the second DM controller 13 in a state in which it can receive in preparation for receiving various frames (S11).

Next, when the modulated radio signal of the ALTS frame (RTS) is input to the radio transceiver module 14 from an external transmitter, the signal is demodulated and output as a KP escape signal, and this signal is transmitted through the modem 12. Converted to RTS frame.

Next, the RTS frame is transmitted to the frame controller 9 through the receiving frame decoder 11 and the checker 8. At this time, the transmission frame decoder 10 is decoded to determine whether an RTS frame (RTS) has been received. Meanwhile, the RTS frame RTS is also transmitted to the second DM controller 13.

Then, the frame controller 9 outputs the first address of the received linked list to the memory 15 from the first register unit 6 to output the CTS frame CTS.

Then, the memory 15 outputs the CTS frame (CTS) corresponding to the first address of the received linked list to the modem 12 via the first DM controller 5, and the modem 12 and radio transmission and reception. The radio signal is transmitted to the counterpart through modulation of the module 14.

Next, the other side receives the CTS frame CTS and transmits the data frame DATA1, which is stored in the memory 15 under the control of the second DM controller. Here, the second DM controller 13 may store all received frames by allocating a predetermined area of the memory, and delete the frames after storing the next frame by overwriting the frames except the data frame.

On the other hand, the frame controller 9 confirms that the correct data frame DATA1 has been received by the reception frame decoder 11, the transmission frame decoder 10, and the checker 8 described above, and determines the address of the ack frame ACK. Output to the memory 15.

Then, the memory 15 outputs the ACK frame ACK through the modem 12 and the wireless transmission / reception module 14, and the counterpart receives the ACK frame ACK and transmits another data frame DATA2 again. .

Then, as in the above process, the received data frame DATA2 is stored in the memory 15, and an acknowledgment frame ACK indicating that the data frame DATA2 has been correctly received is transmitted to the counterpart. At this time, the frame controller 9 requests an interrupt to the central processing unit 4 (S12), and transmits a report on the transmission (S13).

Then, the central processing unit 4 processes the data frames DATA1 and DATA2 stored in the memory with reference to the report and sends them to the computer 1 through the interface unit 3.

According to the present invention by the above process, the first DM controller and the second DM controller perform hardware-related tasks on the transmission / reception of a frame, which is conventionally performed by a central processing unit in software, according to a preset linked list. By doing so, the speed of execution can be increased.

As described above, the present invention performs the transmission and reception of the WLAN data in hardware by the DM controller to exactly match the timing and transmission time suggested in the protocol of the WLAN, by supporting all sequences of the basic protocol, as well as optional It is possible to provide a WLAN device and a control method thereof capable of supporting a point coordination function.

Claims (6)

In a WLAN device, An interface unit for interfacing with a computer; A memory for storing data incorporating a control program; A first DM controller for outputting a control signal to transmit and receive the corresponding frame according to the address of the stored linked list; Receives computer data from the interface unit, creates a linked list of each frame and frame according to a frame exchange sequence, stores the linked list in the memory, and stores the first address of the linked list in the first DM controller. A processing device; A modem for modulating the output signal of the first DM controller in a predetermined manner and demodulating the received signal and transmitting the demodulated signal to the first DM controller; A wireless transmission / reception module for modulating and transmitting a signal output from the modem into a radio signal, and converting the received radio signal into a digital signal; And a second DM controller controlling to store the signal received from the modem in the memory. In claim 1, The first DM controller, A first register unit for embedding a first address of a linked list of frames related to a previously stored reception; A second register unit which stores a first address of a device linked list stored in the memory; A frame controller which receives the first register unit, the second register unit, and a check signal and transmits a corresponding frame of the memory to the modem, and provides a report to the central processing unit when the reception is completed; A transmission frame decoder which receives the output of the frame controller and decodes a frame to be received; A reception frame decoder for decoding a frame received from the modem; And a checker for comparing the frames of the transmission frame decoder and the reception frame decoder to output the check signal. In claim 2, The report transmitted by the frame controller to the central processing unit includes information on a retransmission request, information on the presence or absence of an error, and information on correctly transmitting data. In claim 3, Upon reception completion, the CPU processes the data frame of the memory with reference to the report and transmits the data frame to a computer. Creating and storing a transmission frame and a data frame incorporating information about a length and a transmission of data according to the frame exchange sequence; And transmitting the transmission frame and the data frame sequentially and waiting for a processing result. Initializing a receiving DM controller to receive a predetermined frame; Control method of a wireless LAN device comprising the step of waiting for the reception result of the received frame.