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wlanAMPDUDeaggregate

Deaggregate A-MPDU and extract MPDUs

Description

example

[mpduList,failCRC,status] = wlanAMPDUDeaggregate(ampdu,phyFormat) recovers mpduList, a list of medium access control (MAC) protocol data units (MPDUs), by deaggregating ampdu, an aggregate MPDU (A-MPDU). The function deaggregates the A-MPDU by using parameters appropriate for phyFormat, the physical layer (PHY) format.

The function also returns failCRC, the delimiter cyclic redundancy check (CRC) status for subframes found in ampdu, and status, the status of A-MPDU deaggregation.

example

[mpduList,failCRC,status] = wlanAMPDUDeaggregate(ampdu,cfgPHY) deaggreagates the A-MPDU by using PHY transmission parameters cfgPHY.

example

[mpduList,failCRC,status] = wlanAMPDUDeaggregate(___,Name,Value) specifies options using one or more name-value pair arguments in addition to any input argument combination from previous syntaxes.

Examples

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Create a WLAN MAC frame configuration object, specifying the frame type, frame format, and MPDU aggregation.

cfgMAC = wlanMACFrameConfig('FrameType','QoS Data', ...
    'FrameFormat','HT-Mixed','MPDUAggregation',1);

Create an HT configuration object, specifying MPDU aggregation.

cfgPHY = wlanHTConfig('AggregatedMPDU',1);

Create a random payload of eight MSDUs, and then use it generate an A-MPDU in bit form.

payload = repmat({randi([0 255],1,40)},1,8);
ampdu = wlanMACFrame(payload,cfgMAC,cfgPHY,'OutputFormat','bits');

Return the list of MPDUs by deaggregating the A-MPDU.

phyFormat = 'HT';
[mpduList,failCRC,status] = wlanAMPDUDeaggregate(ampdu,phyFormat);

Confirm successful deaggregation by displaying the result of the delimiter CRC and the decoding status.

disp(failCRC)
   0   0   0   0   0   0   0   0
disp(status)
    Success

Create a WLAN MAC frame configuration object, specifying the frame type and frame format.

cfgMAC =  wlanMACFrameConfig('FrameType','QoS Data','FrameFormat','VHT');

Create a VHT configuration object with default settings.

cfgPHY = wlanVHTConfig;

Create a random payload of eight MSDUs, and then use it to generate an A-MPDU in bit form.

payload = repmat({randi([0 255],1,40)},1,8);
ampdu = wlanMACFrame(payload,cfgMAC,cfgPHY,'Outputformat','bits');

Deaggregate the A-MPDU.

[mpduList,failCRC,status] = wlanAMPDUDeaggregate(ampdu,cfgPHY);

Confirm successful deaggregation by displaying the result of the delimiter CRC and the decoding status.

disp(failCRC)
   0   0   0   0   0   0   0   0
disp(status)
    Success

Deaggregate a VHT A-MPDU and decode the extracted MPDUs.

Create a WLAN MAC frame configuration object for a VHT A-MPDU.

txCfgMAC = wlanMACFrameConfig('FrameType','QoS Data','FrameFormat','VHT');

Create a VHT-format configuration object with default settings.

cfgPHY = wlanVHTConfig;

Generate a random payload of eight MSDUs.

txPayload =  repmat({randi([0 255],1,40)},1,8);

Generate the A-MPDU containing eight MPDUs for the specified MAC and PHY configurations.

ampdu = wlanMACFrame(txPayload,txCfgMAC,cfgPHY);

Extract the list of MPDUs by deaggregating the A-MPDU. Display the status of the deaggregation and the delimiter CRC.

[mpduList,failCRC,status] = wlanAMPDUDeaggregate(ampdu,cfgPHY,'DataFormat','octets');
disp(status)
    Success
disp(failCRC)
   0   0   0   0   0   0   0   0

Decode all of the MPDUs in the extracted. Confirm successful decoding by displaying the status.

if strcmp(status,'Success')
    for i = 1:numel(mpduList)
        if ~failCRC(i)
            [cfgMAC,payload,status(i)] = ...
                wlanMPDUDecode(mpduList{i},cfgPHY,'DataFormat','octets');
        end
    end
end
disp(status)
  Columns 1 through 7

    Success    Success    Success    Success    Success    Success    Success

  Column 8

    Success

Input Arguments

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A-MPDU to be deaggregated, specified as one of these values.

  • A binary-valued vector representing the A-MPDU in bit format

  • A vector of integers in the interval [0, 255] representing octets in decimal format

  • A string scalar representing the A-MPDU as octets in hexadecimal format

  • A character vector representing the A-MPDU as octets in hexadecimal format

  • A character array, where each row represents an octet in hexadecimal format

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | char | string

PHY format, specified as one of these values.

  • 'HE-SU' — High-efficiency single-user (HE SU) format

  • 'HE-EXT-SU' — HE extended-range SU (HE ER SU) format

  • 'HE-MU' — HE multi-user (HE MU) format

  • 'HE-TB' — HE trigger-based (HE TB) format

  • 'VHT' — Very-high-throughput (VHT) format

  • 'HT' — High-throughput (HT) format

Data Types: char | string

PHY format and transmission parameters, specified as one of these objects.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'DataFormat','octets'

Format of input A-MPDU, specified as the comma-separated pair consisting of 'DataFormat' and one of these values.

  • 'bits' — Specify the ampdu input in bit format

  • 'octets' — Specify the ampdu input in octet format

Data Types: char | string

Suppress warning messages, specified as the comma-separated pair consisting of 'SuppressWarnings' and one of these values.

  • false or 0 — Allow warning messages.

  • true or 1 — Suppress warning messages.

Data Types: logical

Output Arguments

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List of MPDUs, returned as a cell array of character arrays, where each character array corresponds to one MPDU. In these character arrays, each row is the hexadecimal representation of an octet.

If no MPDU delimiter is found in the input A-MPDU, the function returns mpduList as an empty cell array.

Data Types: cell

Delimiter CRC failure indicator, returned as a row vector of logical values. Each element of this vector indicates the delimiter CRC failure status for an A-MPDU subframe.

A value of 1 for the kth element of this vector indicates that the delimiter CRC failed for the kth A-MPDU subframe. In this case, the kth element of mpduList contains an MPDU that might be invalid.

A value of 0 for the kth element of this vector indicates that the delimiter CRC passed for the kth subframe. In this case, the kth element of mpduList contains a valid MPDU.

Data Types: logical

Status of A-MPDU deaggregation, returned as a nonpositive integer in the interval [–20, 0]. Each enumeration value of status corresponds to a member of the wlanMACDecodeStatus enumeration class, which indicates the status of MAC frame parsing according to this table.

Enumeration valueMember of enumeration classDecoding Status
0SuccessMAC frame successfully decoded
–1FCSFailedFrame check sequence (FCS) failed
–2InvalidProtocolVersionInvalid protocol version
–3UnsupportedFrameTypeUnsupported frame type
–4UnsupportedFrameSubtypeUnsupported frame subtype
–5NotEnoughDataInsufficient data to decode the frame
–6UnsupportedBAVariantUnsupported variant of Block Ack frame
–7UnknownBitmapSizeUnknown bitmap size
–8UnknownAddressExtModeUnknown address extension mode
–9MalformedAMSDULengthMalformed aggregated MAC service data unit (A-MSDU) with invalid length
–10MalformedSSIDMalformed service set identifier (SSID) information element (IE)
–11MalformedSupportedRatesIEMalformed supported rates IE
–12MalformedIELengthMalformed IE length field
–13MissingMandatoryIEsMandatory IEs missing
–14NoMPDUFoundNo MPDU found in the A-MPDU
–15CorruptedAMPDUAll the delimiters in the given A-MPDU failed the cyclic redundancy check (CRC)
–16InvalidDelimiterLengthInvalid length field in MPDU delimiter
–17MaxAMSDULenthExceededA-MSDU exceeds the maximum length limit
–18MaxMPDULengthExceededMPDU exceeds the maximum length limit
–19MaxMMPDULengthExceededMAC management frame exceeds the maximum length limit
–20MaxMSDULengthExceededMSDU exceeds the maximum length limit
–21UnexpectedProtectedFrameInvalid value of protected bit for this frame type

An enumeration value other than 0 means that A-MPDU deaggregation stopped because the input A-MPDU is corrupt or malformed.

Data Types: int16

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Introduced in R2019a