KR100912079B1 - Aggregated data processing in wireless network - Google Patents

Abstract

According to the present invention, when using frame set transmission to effectively use a channel in a wireless local area network (WLAN), a delay between frames is received when receiving data for supporting CCMP (Counter-mode / CBC-MAC Protocol) and the delayed data and The present invention relates to an aggregate frame processing apparatus and a method for separating and storing data and synchronizing for each MAC protocol data unit (MPDU), and a method thereof. The aggregate frame processing for supporting CCMP in a wireless local area network using the aggregate frame. An apparatus, comprising: first storage means for storing synchronization information; Second storage means for storing the released MAC Protocol Data Unit (MPDU) data; An aggregation frame processing means for releasing the received aggregation frame, storing the MPDU data in which the aggregation is released, in the second storage means, and storing the synchronization information in the first storage means; And control means for reading the synchronization information from the first storage means and controlling the second storage means according to the synchronization information to transfer data to the CCMP decoder.

Set, frame, processing, CCMP, cipher, decryption, sync, delay, MAC

Description

Aggregated frame processing apparatus and method thereof in wireless network

The present invention relates to a technique for processing aggregate frames in a wireless network. More specifically, when using frame aggregate transmission to effectively use a channel in a wireless local area network (WLAN), it supports CCMP (Counter-mode / CBC-MAC Protocol). The present invention relates to an aggregate frame processing apparatus and a method for delaying an interframe when receiving data, storing the delayed data into data information and data, and performing decoding by synchronizing for each MAC protocol data unit (MPDU).

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management Number: 2006-S-014-02, Title: 200Mbps IEEE 802.11n Modem] And RF chipset development].

There is an 802.11 task group N for supporting high-speed data processing in an IEEE 802.11 wireless local area network, which is a wireless local area network (WLAN) system standard. In task group N, an Aggregation Frame (A-MSDU) transmission is defined for high speed data processing.

In general, a response policy of a distributed coordination function (DCF) includes one response frame sequence for one MAC protocol data unit (MPDU) unit frame. At this time, an interval equal to the SIFS (Short Inter frame Space) defined in the DCF is required between the MPDU frame and the response frame. When one MAC Service Data Unit (MSDU) frame is fragmented and composed of multiple MPDUs, multiple transmission is performed. Multiple transmission can reduce delay time due to BACK OFF of DCF by sending the next MPDU within SIFS after MPDU frame and response frame sequence. Therefore, when one frame is successfully transmitted during transmission using a general DCF mechanism, a transmission time for transmitting SIFS and response frames is required in addition to the actual data transmission time.

1 is a diagram illustrating a multi-frame response sequence using a general DCF mechanism. 2 is a diagram illustrating a protocol message sequence of a general block response policy.

Aggregate frame transmission defined in 802.11n is a group of multiple frames destined for one destination to be transmitted as a single frame, and thus the channel can be used more efficiently. This transmission method has the effect of eliminating the SIFS interval in the method of transmitting data by placing the SIFS interval of the block response transmission frame defined in 802.11e.

In the block response transmission process, a transmitting terminal performs multiple transmissions within SIFS without waiting for a response to data transmitted in a block unit. The MSDU (consisting of n MPDUs) having a predetermined block response size is completed. Thereafter, a block acknowledgment frame is transmitted and a block acknowledgment frame is received by the receiving terminal.

FIG. 3 is a diagram illustrating a protocol message sequence of a general AGGREGATION frame policy used in a wireless local area network, and FIG. 4 is a diagram illustrating a CCMP frame structure.

In 802.11n, CCMP is supported for security. CCMP processes data in 16 byte units and performs encryption and decryption. Thus, there is a delay per MPDU to process data in units of 16 bytes. However, since a plurality of MPDU packets must be processed in real time when receiving an aggregate frame, it is necessary for the CCMP decoding block to delay data for processing 16 bytes.

Accordingly, the present invention has been proposed to solve the above problems of the prior art. When using an aggregated frame in a wireless local area network (WLAN), a delay between frames is received when receiving data for supporting CCMP, and the delayed data is converted into data information. An object of the present invention is to provide an apparatus and a method for processing an aggregate frame capable of performing decoding by dividing and storing data into data and synchronizing them for each MAC protocol data unit (MPDU).

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An aggregate frame processing apparatus according to the present invention for achieving the above object comprises: an aggregate frame processing apparatus for supporting CCMP in a wireless local area network using the aggregate frame, comprising: first storage means for storing synchronization information; Second storage means for storing the released MAC Protocol Data Unit (MPDU) data; An aggregation frame processing means for releasing the received aggregation frame, storing the MPDU data in which the aggregation is released, in the second storage means, and storing the synchronization information in the first storage means; And control means for reading the synchronization information from the first storage means and controlling the second storage means according to the synchronization information to transfer data to the CCMP decoder.

In addition, the aggregate frame processing method according to the present invention, the aggregate frame processing method for supporting CCMP in a wireless local area network using the aggregate frame, comprising the steps of: (a) releasing the aggregate frame; (b) storing the synchronization information in the first storage means, and storing the decompressed MAC Protocol Data Unit (MPDU) data in the second storage means; And (c) controlling the second storage means according to the synchronization information to transfer data to the CCMP decoder using the synchronization information stored in the first storage means.

As described above, the present invention has an effect of delaying data between MPDUs during the aggregation frame processing and facilitating encryption and decryption processing in a CCMP block through synchronization between data and data information.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a block diagram of an aggregate frame processing apparatus according to the present invention.

The aggregate frame processing apparatus according to the present invention processes a synchronization information storage FIFO 602 for storing information to be used for CCMP decoding, an MPDU storage FIFO 603 for storing data to be used for CCMP decoding, and a received aggregate frame. And an aggregation frame processor 601 for storing MPDU length information, header length information, and CRC check result in the synchronization information storage FIFO 602, and storing data in the MPDU storage FIFO 603, and the synchronization information storage FIFO ( And a control unit 604 that reads the information stored in 602 and generates a control signal for controlling the CCMP decoding unit 605.

Hereinafter, an aggregate frame processing apparatus for supporting CCMP according to the present invention will be described in detail with reference to the accompanying drawings.

6 is a view for explaining a synchronization information storage FIFO according to the present invention.

The synchronization information storage FIFO is a storage memory that stores information necessary for performing CCMP decoding. It is initialized every time an aggregate frame is received and stored one for each de-aggregated MPDU.

The information stored in the synchronization information storage FIFO includes 'M_LEN', which is the overall length of the MPDU, and 'OK', 'ERR', which is the result of the 'H_LEN' CRC test, which is the length of the MPDU header. 'M_LEN' used when performing CCMP decoding is delivered to a CCMP decoding block, and H_LEN and CRC check result information are used as a CCMP decoding block interface control signal.

The data storage FIFO is a storage memory for storing MPDU data to be CCMP decoded. It is initialized each time a collection frame is received and stored one for each released MPDU.

7 is a view for explaining the processing of the collective frame processing unit according to the present invention.

The aggregation frame processing unit 601 releases the aggregation frame when the aggregation frame is received in the idle state. When the aggregation is released, the aggregation frame processing unit 601 reads length information of the MPDU from the delimiter of the frames where the aggregation is released and stores the length information of the MPDU in the synchronization information storage FIFO 602 (701).

The aggregation frame processing unit 601 reads the length information of the MAC header from the header information of the released MPDU and stores it in the synchronization information storage FIFO 602 (702). 8 is a diagram illustrating length information of a MAC header according to control field information.

After performing the CRC check on the MPDU in which the set is released, the aggregation frame processing unit 601 stores the CRC check result in the synchronization information storage FIFO 602 (703). The CRC check result is stored in order to discard an error packet without performing decryption when performing decryption.

The aggregation frame processor 601 increments the information storage counter to store the next MPDU when all the information is stored for one MPDU. This information storage counter is restarted from '0' when the maximum number (MAX_N) that the synchronization information storage FIFO can store.

The aggregation frame processing unit 601 performs a process of releasing the aggregation frame again if there is a packet whose aggregation is released after the information storage counter is incremented. In this case, the aggregation frame processing unit 601 does not initialize the information stored in the synchronization information storage FIFO, but does not initialize the data, and initializes the stored information when a new aggregation frame is received.

9 is a view for explaining a process of the control unit according to the present invention, Figure 10 shows a timing diagram of the control unit.

The controller 604 reads the length information of the corresponding MPDU to be decoded from the information usage counter position of the synchronization information storage FIFO 602 when notified that one aggregate frame has been stored from the aggregate frame processing unit in the idle state, and the MPDU length information is read. In step 901, the CCMP decoder 605 transmits the information to the CCMP decoder 605.

The controller 604 generates a header enable (HEADER_EN) signal as much as the header length information (H_LEN) stored in the synchronization information storage FIFO 602 in order to pass the MAC header to the CCMP decoder 605 to perform decoding. Forward to storage FIFO 603 (902). Accordingly, the MAC header and the CCMP header are transferred from the MPDU storage FIFO 603 to the CCMP decoder 605.

Next, the controller 604 waits for a signal indicating that it is ready to decode from the CCMP decoder 605 that has received the MAC header information, and then receives a data request signal DATA_REQ to be decoded from the CCMP decoder 605 (903). In order to transfer the data stored in the MPDU storage FIFO 603 to the CCMP decoder 605, a data enable (SI_DA_EN) signal is generated and transmitted to the MPDU storage FIFO 603 as much as MPDU length information (904). Accordingly, encrypted MPDU data is transferred from the MPDU storage FIFO 603 to the CCMP decryption unit 605.

If the controller 604 receives a message indicating that the MAC header cannot be decoded from the CCMP decoder 605, the MPDU data cannot be decoded, and thus the MPDU storage FIFO 603 deletes the MPDU data (906). ).

The CCMP decoder 605 performs MIC check on the decoded data. If the control unit 604 is notified of the Message Integrity Code (MIC) check error from the CCMP decoder 605 (905), the control unit 604 deletes the error MPDU data from the MPDU storage FIFO (906). In this case, the MIC check means a check to verify the integrity of the data.

The CCMP decoder 605 transmits the data not in error through the MIC check to the upper layer (907).

When the decoding process is completed for one MPDU, the controller 604 increments an information usage counter to process the next MPDU (908). The information usage counter, like the information storage counter, is initialized to '0' upon receipt of a new aggregated frame.

As described above, according to the present invention, in order to efficiently use a channel in a wireless local area network and to support high-speed data transmission, the present invention delays data for encrypting and decrypting an aggregated frame defined by 802.11n using CCMP. Deliver to CCMP decoder.

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

1 illustrates a frame response sequence using a general DCF mechanism;

2 illustrates a message sequence of a protocol of a general block response policy;

3 is a diagram illustrating an aggregate frame transmission sequence;

4 is a view showing a CCMP frame structure,

5 is a block diagram of a collective frame processing apparatus according to the present invention;

6 is a view for explaining a synchronization information storage FIFO according to the present invention;

7 is a view for explaining the operation of the aggregate frame processing unit according to the present invention;

8 is a diagram illustrating length information of a MAC header according to control field information;

9 is a view for explaining the processing of the control unit according to the present invention;

10 is an operation timing diagram of an aggregate frame processing apparatus according to the present invention.

* Explanation of symbols for the main parts of the drawings

601: aggregation frame processing unit 602: synchronization information storage FIFO

603: MPDU storage FIFO 604: control unit

605: CCMP decoder

Claims (13)

In the aggregate frame processing apparatus for supporting CCMP in a wireless local area network using an aggregate frame, First storage means for storing synchronization information; Second storage means for storing the released MAC Protocol Data Unit (MPDU) data; An aggregation frame processing means for releasing the received aggregation frame, storing the MPDU data in which the aggregation is released, in the second storage means, and storing the synchronization information in the first storage means; And Control means for reading said synchronization information from said first storage means and controlling said second storage means in accordance with said synchronization information to transfer data to a CCMP decoder; Aggregate frame processing apparatus comprising a. The method of claim 1, The synchronization information, And a length information of the MPDU, header length information, and a CRC check result. The method of claim 2, The aggregate frame processing means, Read the length information of the MPDU from the delimiter of the de-set frame, store in the first storage means, read the length information of the MAC header from the header information of the MPDU, and store in the first storage means, CRC of the MPDU And an inspection result stored in the first storage means. The method of claim 3, wherein The aggregate frame processing means, And storing the information for one MPDU, incrementing an information storage counter to store the next MPDU. The method of claim 4, wherein And the information storage counter is initialized when the maximum number that the first storage means can store is initialized. The method of claim 3, wherein The aggregate frame processing means, Collecting frame processing apparatus characterized in that for initializing the information stored in the first storage means when receiving a new aggregated frame. The method of claim 2, The control means, In order to transfer the header information to the CCMP decoder, a header enable signal is generated to the second storage means, and when a data request is received from the CCMP decoder, a data enable signal is generated as long as an MPDU length to the second storage means. An assembly frame processing apparatus, characterized in that. The method of claim 7, wherein The control means, And the MPDU length information read from the first storage means is transferred to the CCMP decoder. The method of claim 7, wherein The control means, And reading out the header length information from the first storage means to generate a header enable signal as much as the read header length information. The method of claim 7, wherein The control means, And receiving the message indicating that the MAC header cannot be decoded from the CCMP decoder, deleting the corresponding MPDU data from the second storage means. The method of claim 7, wherein The control means, And receiving the message integrity error (MIC) test error from the CCMP decoder, deleting the MPDU data having the error from the second storage means. The method of claim 7, wherein The control means, And an information usage counter is increased to process the next MPDU when the decoding process is completed for one MPDU. In the aggregate frame processing method for supporting CCMP in a wireless local area network using the aggregate frame, (a) releasing the aggregation frame; (b) storing the synchronization information in the first storage means, and storing the decompressed MAC Protocol Data Unit (MPDU) data in the second storage means; And (c) controlling the second storage means according to the synchronization information to transfer data to the CCMP decoder using the synchronization information stored in the first storage means. Set frame processing method comprising a.

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