OFDM SIG Info (802.11n/ac/ax/be)
The summary trace shows the following SIG field information.
- HE-SIG-A (High Efficiency Signal) - HE-SIG-A for 802.11ax
- EHT-U-SIG (Extremely High Throughput Universal Signal) - EHT-U-SIG for 802.11be
- EHT-SIG (Extremely High Throughput Signal) - Common section of EHT-SIG content channel 1 and content channel 2 (When applicable) for 802.11be
- VHT-SIG (Very High Throughput Signal) - VHT very high throughput (VHT) physical (PHY) layer protocol data unit (PPDU):A PPDU transmitted using the TXVECTOR FORMAT parameter equal to VHT.-SIG-A1/VHT-SIG-A2 and VHT-SIG-B for 802.11ac
- HT-SIG (High Throughput Signal) - HT-SIG High-Throughput SIGNAL field for 802.11n
- L-SIG (Legacy Signal) - L-SIG Non-HT SIGNAL field field information for applicable 802.11n/ac signals
Numerical values are shown on the trace in decimal format unless prefixed by "0x" to indicate hexidecimal format.
HE-SIG-A
The HE-SIG-A field on the trace shows the combined status of the HE-SIG-A1 and A2 symbols:
- CRCPassed - Cyclic Redundancy Check passed
- CRCFailed - Cyclic Redundancy Check failed
The following table describes the elements in the HE-SIG-A1 and A2 symbols in the preamble which are shown in the trace. The fields are listed in the same order as they appear in the standard in Section 28.3.10.7.2.
| VSA Field Name | IEEE Standard Field Name | Explanation |
|---|---|---|
| HE SU Single user/ER SU/MU Multi-user PPDU PLCP Protocol data unit common fields | ||
| UL Up Link (reverse link: from cell phone to base station)/DL Down Link (forward link: from base station to cell phone) | UL/DL | Indicate whether the PPDU is sent UL or DL |
| BSSColor | BSS Basic Service Set: 1) A set of stations controlled by a single coordination function. OR 2) 802.11 An area of coverage, or "cell" established by an 802.11 wireless OR 3) The set of data transfer rates that all the stations in a BSS will be capable of using to receive and transmit frames to/from the wireless medium (WM). The BSS basic rate set data rates are preset for all stations in the BSS.OR 3) Basic Service Set Basic Rate Set: access point. 802.11 WLAN clients within range of the access point can associate with it, provided they know the SSID for the BSS and can authenticate successfully with the access point. Color | Identifier of BSS |
| SpatialR | Spatial Reuse | A value that is used to determine a limit on the transmit power of a spatial reuse transmission. |
| BW | Bandwidth | HE SU PPDU: Signal bandwidth expressed as: 20MHz, 40MHz, 80MHz, 160MHz, or 80+80MHz. |
| GI Guard interval | GI+LTF Long Training field Size | Indicates the GI duration as : 0.8us，1.6us, 3.2us |
| HE-LTF | GI+LTF Size | Indicates the HE-LTF size as : 1x，2x, 4x |
| NSTS | Nsts |
HE SU PPDU : Indicates the number of space time streams as (Nsts - 1) HE ER SU PPDU : 0 indicates one space time stream when STBC Space–Time Block Coding is a alternative to spactial multiplexing used in wireless communications to transmit multiple copies of a data stream across a number of antennas. Particularly useful for systems where the number of receive antennas is less than the number of transmit antennas.and to exploit the various received versions of the data to improve the reliability of data-transfer. is off and 1 indicates two space time streams when STBC is on. [2:7] are reserved |
| MidambPer | Midamble Periodicity |
Indicates the periodicity of the Midamble, in OFDM Orthogonal Frequency Division Multiplexing: OFDM employs multiple overlapping radio frequency carriers, each operating at a carefully chosen frequency that is Orthogonal to the others, to produce a transmission scheme that supports higher bit rates due to parallel channel operation. OFDM is an alternative tranmission scheme to DSSS and FHSS. symbols. Signals that contain the Midamble are not supported. The Midamble is only present when number of OFDM data symbols is > Midamble Periodicity + 1. Midamble Periodicity can be: *** = not applicable (Doppler = N) 10 = Midamble Periodicity is every 10 OFDM symbols 20 = Midamble Periodicity is every 20 OFDM symbols |
| Coding | Coding | Indicates whether BCC binary convolutional code or LDPC low-density parity check is used. |
| STBC | STBC | Indicates whether space time coding is used or not. |
| PreFECPad | Pre-FEC Forward Error Correction: An encoding technique that allows a limited number of errors in digital stream to be corrected based on knowledge of the encoding scheme used. Padding Factor | Indicates pre-FEC padding factor value as defined in Table28-39 |
| PEDisam | PE Disambiguity | Indicates PE Disambiguity as defined in 28.3.12(Packet extension) |
| Doppler | Doppler |
Y: Doppler mode is used N: Doppler mode is not used |
| CRC Cyclic Redundancy Check | CRC | Value of CRC , MSB Most significant bit. In a binary coding scheme, the bit having the greatest numerical value. Analogous to the left-most numeric position in a decimal number.-first |
| Tail | Tail | Value of tail bits |
| HE SU/ER SU PPDU specific fields | ||
| BeamChg | Beam Change |
Y = pre-HE-STF has different spatial mapping from HE-LTF1 N = pre-HE-STF has same spatial mapping as HE-LTF1 |
| MCS modulation and coding scheme | MCS |
HE SU PPDU : MCS [0:11] is used and [12:15] are reserved HE ER SU PPDU : 1. 242-tone RU MCS [0:2] is used and [3:15] are reserved 2. 106-tone RU MCS 0 is used and [1:15] are reserved |
| DCM | DCM |
Y : DCM is applied N : DCM is not applied |
| TxBF | TxBF |
Y: Beamforming steering matrix is applied N: otherwise |
| HE MU PPDU specific fields | ||
| SIGB-MCS | MCS |
MCS [0:5] is used and [6:7] are reserved |
| SIGB-DCM | DCM |
Y : Indicates that the HE-SIG-B is modulated with dual sub-carrier modulation for the MCS N : Indicates that the HE-SIG-B is not modulated with dual sub-carrier modulation for the MCS |
| SIGB-Syms | Number of HE-SIG-B Symbols or MU-MIMO multi-user, multiple input, multiple output: A technique here multiple STAs, each with potentially multiple antennas, transmit and/or receive independent data streams simultaneously. Users |
SIGB Compression is 0 : indicates the number of OFDM symbols in the HE-SIG-B field SIGB Compression is 1 : indicates the number of MU-MIMO Multiple Input, Multiple Output: A physical layer (PHY) configuration in which both transmitter and receiver use multiple antennas. users |
| SIGB-Comp | SIGB Compression |
1 : full BW MU-MIMO 0 : otherwise |
| HE-LTFSyms | Number of HE-LTF symbols | Indicates the number of HE-LTF symbols |
| HE TB PPDU specific fields | ||
| BSSColor | BSS Color | Identifier of BSS |
| BW | Bandwidth | HE SU PPDU: Signal bandwidth expressed as: 20MHz, 40MHz, 80MHz, 160MHz, or 80+80MHz. |
| SpatialR1 | Spatial Reuse 1 | A value that is used to determine a limit on the transmit power of a spatial reuse transmission if allowed. Set to the value of the SPATIAL_REUSE(1) parameter of the TXVECTOR. |
| SpatialR2 | Spatial Reuse 2 | A value that is used to determine a limit on the transmit power of a spatial reuse transmission if allowed. Set to the value of the SPATIAL_REUSE(2) parameter of the TXVECTOR. |
| SpatialR3 | Spatial Reuse 3 | A value that is used to determine a limit on the transmit power of a spatial reuse transmission if allowed. Set to the value of the SPATIAL_REUSE(3) parameter of the TXVECTOR. |
| SpatialR4 | Spatial Reuse 4 | A value that is used to determine a limit on the transmit power of a spatial reuse transmission if allowed. Set to the value of the SPATIAL_REUSE(4) parameter of the TXVECTOR. |
EHT-U-SIG
For 802.11be signals, the OFDM SIG Info trace shows information decoded from the EHT-U-SIG. U-SIG is transmitted in each 20 MHz Megahertz: A unit of frequency equal to one million hertz or cycles per second. band. It is the same in each 20 MHz band in an 80 MHz subblock, but U-SIG can be different per 80 MHz subblock when BW > 80 MHz.
The OFDM SIG Info trace displays a separate U-SIG section per 80 MHz subblock. The name of each section contains an index that indicates the 80 MHz subblock (indexes increase with frequency). For example, a 320 MHz bandwidth signal will have four EHT-U-SIG sections:
| Subblock 1 (80 MHz) | Subblock 2 (80 MHz) | Subblock 3 (80 MHz) | Subblock 4 (80 MHz) | |||||||
| EHT-U-SIG1 | EHT-U-SIG2 | EHT-U-SIG3 | EHT-U-SIG4 | |||||||
The EHT-U-SIG field on the trace shows the combined status of the EHT-U-SIG:
- CRCPassed - Cyclic Redundancy Check passed
- CRCFailed - Cyclic Redundancy Check failed
MU (Multiple User) PPDU Mode
In MU PPDU mode, the following table describes the elements in the EHT-U-SIG symbols in the preamble which are shown in the trace. The fields are listed in the same order as they appear in Table 36-28 of the 802.11be/D1.1 standard definition.
| VSA Field Name | IEEE Standard Field Name | Explanation |
|---|---|---|
| PHYVersion | PHY Physical Layer Version Identifier | Indicates the differentiation between PHY amendments. 0 = EHT. |
| Bandwidth | Bandwidth | Indicates the EHT signal bandwidth expressed as: 20MHz, 40MHz, 80MHz, 160MHz, or 320MHz. |
| UL/DL | UL/DL | Indicate whether the frame is uplink or downlink. |
| BSSColor | BSS Color | Identifier of BSS. |
| TXOP | TXOP | Indicates the TXOP Duration. |
| Disregard | Disregard | |
| Validate | Validate | |
| PPDUType | PPDU Type And Compression Mode | Indicates the PPDU type as part of the 2-bit PPDU Type and Compression Mode field. |
| Compression | PPDU Type And Compression Mode | Indicates the compression mode as part of the 2-bit PPDU Type And Compression Mode field. |
| Validate | Validate | |
| Punc Value | Punctured Channel Information | Indicates the puncture value used as part of the 5-bit EHT-U-SIG Punctured Channel Information field. Punctured channel information is defined in Table 36-30 of the 802.11be/D1.1 standard definition. |
| Punc Pattern | Punctured Channel Information |
Indicates the puncturing pattern used as part of the 5-bit EHT-U-SIG Punctured Channel Information field. Punctured channel information is defined in Table 36-30 of the 802.11be/D1.1 standard definition. When bandwidth is < 80 MHz, this field shows "---" since puncturing is not available for bandwidths lower than 80 MHz. |
| Validate | Validate | |
| EHT-SIG MCS | EHT-SIG MCS | Indicates the MCS used to modulate the EHT-SIG. |
| EHT-SIG Syms | Number of EHT-SIG Symbols | Indicates the number of EHT-SIG symbols. |
| CRC | CRC | Value of CRC , MSB-first |
| Tail | Tail | Value of tail bits |
TB (Trigger Based) PPDU Mode
In TB PPDU mode, the following table describes the elements in the EHT-U-SIG symbols in the preamble which are shown in the trace. The fields are listed in the same order as they appear in Table 36-31 of the 802.11be/D1.1 standard definition.
| VSA Field Name | IEEE Standard Field Name | Explanation |
|---|---|---|
| PHYVersion | PHY Version Identifier | Indicates the differentiation between PHY amendments. 0 = EHT. |
| Bandwidth | Bandwidth | Indicates the EHT signal bandwidth expressed as: 20MHz, 40MHz, 80MHz, 160MHz, or 320MHz. |
| UL/DL | UL/DL | Indicate whether the frame is uplink or downlink. |
| BSSColor | BSS Color | Identifier of BSS. |
| TXOP | TXOP | Indicates the TXOP Duration. |
| Disregard | Disregard | |
| PPDUType | PPDU Type And Compression Mode | Indicates the PPDU type as part of the 2-bit PPDU Type and Compression Mode field. |
| Compression | PPDU Type And Compression Mode | Indicates the compression mode as part of the 2-bit PPDU Type And Compression Mode field. |
| Validate | Validate | |
| SpatialReuse1 | Spatial Reuse 1 | Set to the value of the SPATIAL_REUSE(1) parameter of the TXVECTOR. |
| SpatialReuse2 | Spatial Reuse 2 | Set to the value of the SPATIAL_REUSE(2) parameter of the TXVECTOR. |
| Disregard | Disregard | |
| CRC | CRC | Value of CRC , MSB-first |
| Tail | Tail | Value of tail bits |
EHT-SIG
For 802.11be signals, the OFDM SIG Info trace shows information decoded from the common section of the EHT-SIG content channel. The VSA software supports multiple EHT-SIG sections. EHT-SIG is transmitted in each 20 MHz band. There are two content channels per 80 MHz subblock that are repeated within the subblock, but can be different per subblock. For an OFDMA MU PPDU, the content channels can have different contents from each other, as well as different contents in each 80 MHz subblock. This means that, for 320 MHz bandwidth, there are 8 possible EHT-SIG transmissions with different contents. There is a separate section in the SIG Info table for each. The index in the EHT-SIG name indicates the content channel and 80 MHz subblock.
1 = content channel 1, subblock 1
2 = content channel 2, subblock 1
3 = content channel 1, subblock 2
4 = content channel 2, subblock 2
etc.
For example, a 160 MHz bandwidth signal will have four EHT-SIG sections:
| Subblock 1 (80 MHz) | Subblock 2 (80 MHz) | |||||||||
| EHT-SIG1 | EHT-SIG2 | EHT-SIG3 | EHT-SIG4 | |||||||
| Content Channel 1 | Content Channel 2 | Content Channel 1 | Content Channel 2 | |||||||
The EHT-SIG field on the trace shows the contents of the common section of each EHT-SIG content channel, plus the encoding block CRCs and Tail Bits. The possible status results for each content channel are:
- CRCPassed -- all Cyclic Redundancy Checks passed
- CRCFailed -- one or more Cyclic Redundancy Checks failed
MU (OFDMA) PPDU
In MU (OFDMA) PPDU mode, the following table describes the elements in the common field of the EHT-SIG content channel which are shown in the trace. The elements are listed in the same order as they appear in Table 36-33 of the 802.11be/D1.1 standard definition. Information for the user-specific field of the EHT-SIG content channel is shown in the OFDM Multi-User Info trace.
| VSA Field Name | IEEE Standard Field Name | Explanation |
|---|---|---|
| SpatialR | Spatial Reuse | A value that is used to determine a limit on the transmit power of a spatial reuse transmission. |
| GI | GI+LTF Size | Indicates the GI duration as: 0.8µs，1.6µs, 3.2µs. |
| EHT-LTF Size | GI+LTF Size | Indicates the EHT-LTF size as: 2x, 4x. |
| EHT-LTF Syms | Number of EHT-LTF Symbols | Indicates the number of EHT-LTF symbols. |
| LDPC Extra | LDPC extra symbol segment | Indicates the presence of the LDPC extra symbol segment. |
| Pre-FEC Pad | Pre-FEC padding factor | Indicates pre-FEC padding factor. |
| PE Disamb | PE Disambiguity | Indicates PE Disambiguity. |
| Disregard | Disregard | |
| RU Alloc-1 | RU Allocation-1 | The RU Alloc fields indicate the size and location of the RUs or MRUs in frequency. RU Alloc-1 can have one or two subfields (1/0, 1/1), depending on bandwidth. |
| CRC_block1 | CRC | Value of CRC for the first encoding block, MSB-first |
| Tail | Tail | Value of tail bits for the first encoding block |
| RU Alloc-2 | RU Allocation-2 | The RU Alloc fields indicate the size and location of the RUs or MRUs in frequency. RU Alloc-2 is present for 160 MHz and greater bandwidths and can have 0, 2 or 6 subfields, depending on bandwidth. |
| CRC_block2 | CRC | Value of CRC for the second encoding block, MSB-first. CRC_block2 is present for 160 MHz and greater bandwidths. |
| Tail | Tail | Value of tail bits for the second encoding block. This Tail field is present for 160 MHz and greater bandwidths. |
MU (Non-OFDMA) PPDU
In MU (non-OFDMA) PPDU mode, the following table describes the elements in the common field of the EHT-SIG content channel which are shown in the trace. The elements are listed in the same order as they appear in Table 36-36 of the 802.11be/D1.1 standard definition. Information for the user-specific field of the EHT-SIG content channel is shown in the OFDM Multi-User Info trace.
| VSA Field Name | IEEE Standard Field Name | Explanation |
|---|---|---|
| SpatialR | Spatial Reuse | A value that is used to determine a limit on the transmit power of a spatial reuse transmission. |
| GI | GI+LTF Size | Indicates the GI duration as : 0.8µs，1.6µs, 3.2µs. |
| EHT-LTF Size | GI+LTF Size | Indicates the EHT-LTF size as : 2x, 4x. |
| EHT-LTF Syms | Number of EHT-LTF Symbols | Indicates the number of EHT-LTF symbols. |
| LDPC Extra | LDPC extra symbol segment | Indicates the presence of the LDPC extra symbol segment. |
| Pre-FEC Pad | Pre-FEC padding factor | Indicates pre-FEC padding factor. |
| PE Disamb | PE Disambiguity | Indicates PE Disambiguity. |
| Disregard | Disregard | |
| Users | Number of Non-OFDMA Users | Indicates the number of users defined by EHT-SIG. |
| CRC | CRC | Value of CRC, MSB-first |
| Tail | Tail | Value of tail bits |
VHT-SIG
For 802.11ac signals, the OFDM SIG Info trace shows information decoded from the VHT-SIG symbols: VHT-SIG-A1, VHT-SIG-A2, and VHT-SIG-B (for single-user signals).
Section 22.3.8.2.3 in the 802.11ac standard defines the contents of VHT-SIG-A1 and A2. Section 22.3.8.2.6 defines the contents of VHT-SIG-B.
VHT-SIG-A
The VHT-SIG-A field on the trace shows the combined status of the VHT-SIG-A1 and A2 symbols:
- CRCPassed - Cyclic Redundancy Check passed
- CRCFailed - Cyclic Redundancy Check failed
- None - no VHT-SIG-A field present
- Unknown - status is unknown
The following table describes the elements in the VHT-SIG-A1 and A2 symbols in the preamble which are shown in the trace. The fields are listed in the same order as they appear in the standard in Section 22.3.8.2.3.
| VSA Field Name | IEEE Institute of Electrical and Electronics Engineers. A US-based membership organisation that includes engineers, scientists, and students in electronics and related fields. The IEEE developed the 802 series wired and wireless LAN standards. Visit the IEEE at http://www.ieee.org Standard Field Name | Explanation |
|---|---|---|
| VHT-SIG-A1 | ||
| BW | BW | Signal bandwidth expressed as: 20MHz, 40MHz, 80MHz, 160MHz, or 80+80MHz. |
| Reserved | Reserved | Value of reserved bit: 0 or 1 |
| STBC | STBC |
Y = all users have space time block coding N = no users have space time block coding |
| GroupID | Group ID | 6-bit value of Group ID parameter. |
| NSTS |
NSTS/Partial AID Association identifier |
12 bit field whose contents depend on whether the signal is multi-user or single-user. Multi-user: values of MU[n] NSTS fields separated by semicolons. Example: "2;3;3;0" indicating that MU[0] NSTS = 2, MU[1] NSTS = 3, etc. Single-user: value of SU NSTS followed by value of Partial AID, separated by semicolon. |
| NoTXOPPS | TXOP_PS physical slot: A unit of time, dependent on the PHY specification, for allocating bandwidth. 802.11: Power save (mode)_ NOT_ALLOWED | Value of TXOP_PS_ NOT_ALLOWED bit: 0 or 1 |
| Reserved | Reserved | Value of reserved bit: 0 or 1 |
| VHT-SIG-A2 | ||
| ShortGI | Short GI |
Y = short guard interval used in the VHT-Data field of the preamble. N = short guard interval not used in the VHT-Data field. |
| Coding | SU/MU[0] Coding |
Possible values: BCC, LDPC, or binary digit (indicating the value of a reserved bit). Single-user: indicates the coding used. Multi-user: indicates the coding for user 0. |
| MCS | SU MCS/MU[1-3] Coding |
Single-user: indicates the MCS index. Multi-user: indicates the coding for users 1-3. Values are separated by semicolons: B = BCC, L = LDPC, or binary digit (indicating the value of a reserved bit). |
| Beamform | Beamformed |
Single-user: Y = beamforming is applied N = beamforming is not applied Multi-user: Value of reserved bit: 0 or 1. |
| Reserved | Reserved | Value of reserved bit: 0 or 1 |
| CRC | CRC | Value of CRC, MSB-first (c7...c0) |
| Tail | Tail | Value of tail bits. |
VHT-SIG-B
The VHT-SIG-B field on this trace shows the status of the VHT-SIG-B symbol:
- OK - VHT-SIG-B decoded successfully
- None - no VHT-SIG-B present
The OFDM SIG Info trace shows VHT-SIG-B information for single-user signals; for multi-user VHT-SIG-B info, see the OFDM Multi-User Info summary table for VHT-SIG-B symbols' information.
The following table describes the elements in the VHT-SIG-B symbol in the preamble which are shown in the trace. The fields are listed in the same order as they appear in the standard in Section 22.3.8.2.6.
| VSA Field Name | IEEE Standard Field Name | Explanation |
|---|---|---|
| Length | VHT-SIG-B Length | Value of VHT-SIG-B Length field. Varying number of bits depending on signal bandwidth. |
| MCS | MCS |
*** = Not present Otherwise shows 4-bit MCS value. |
| Reserved | Reserved |
*** = Not present Otherwise shows value of reserved bits. |
| Tail | Tail | Value of tail bits. |
HT-SIG
The field indicates the status of the High Throughput signal:
- CRCPassed - Cyclic Redundancy Check passed
- CRCFailed - Cyclic Redundancy Check failed
- None - Signal does not have an HT high throughput-SIG symbol
- Unknown - Status is not known
Other High Throughput Signal (HT-SIG) fields include the following:
|
Field Name |
Size (bits) |
Explanation |
|---|---|---|
|
Aggreg |
1 |
Aggregation. 1 indicates that the PHY Protocol Data Unit (PPDU) in the data portion of the packet contains an Aggregated Message Protocol Data Unit (A-MPDU aggregate MAC protocol data unit: A structure containing multiple MPDUs, transported as a single physical layer convergence procedure (PLCP) service data unit (PSDU) by the physical layer (PHY).). Aggreg is set to 0 otherwise. |
|
CBW |
1 |
Channel Bandwidth. 0 if 20 MHz or 40 MHz upper or lower bandwidth. 1 if 40 MHz bandwidth. |
|
CRC |
8 |
Cyclic Redundancy Check error correction. CRC of bits 0-23 in HT-SIG1 and bits 0-9 in HT-SIG2. |
|
ExtSStrms |
2 |
Number of extension spatial streams. 00 = no extension spatial streams. 01 = 1 additional spatial stream. 10 = 2 additional spatial streams. 11 = 3 additional spatial streams. |
|
FECCode |
1 |
Forward Error Correction Coding. (FEC or BCC) |
|
HTLen |
16 |
Number of bytes of data in the PHY Service Data Unit (PSDU 1) PHY Service Data Unit, or 2) PLCP SDU). |
|
MCS |
7 |
The Modulation and Coding Scheme (MCS) index value. The MCS determines the modulation, Forward Error Correction (FEC) code and code rate, the number of transmitters, and the number of spatial streams. |
|
NotSnd |
1 |
Indicates if the packet is not a sounding packet. |
|
Resrvd |
1 |
Set to 1. |
|
ShortGI |
1 |
Indicates whether or not the short Guard Interval is used after the High Throughput training. |
|
Smooth |
1 |
1 = Channel estimate smoothing is enabled. 0 = Only per-carrier independent (unsmoothed) channel estimate is recommended. |
|
STBC |
2 |
Space-Time-Block-Coding. Indicates the difference between the number of space time streams and the number of spatial streams. 00 = No STBC |
|
Tail |
6 |
Set to 0. Terminates the trellis of the convolution coder. |
L-SIG
The field indicates the status of the L-SIG symbol:
- Unknown - status not known
- None - signal does not have an L-SIG symbol (HT-greenfield 802.11n signal is an example.)
- Missing - signal should have an L-SIG symbol but symbol not found
- InvalidBits - L-SIG symbol found but Rate bits appear incorrect
- ParityFailed - L-SIG symbol appears OK but parity check failed
- ParityOK - L-SIG symbol appears OK
The other L-SIG fields include the following:
|
Field Name |
Size (bits) |
Explanation |
|---|---|---|
|
Rate |
4 |
Rate field of the L-SIG symbol. Value tells a legacy device the data rate to expect. |
|
Reserved |
1 |
Reserved bit in the L-SIG symbol. |
|
Length |
12 |
Length field of the L-SIG symbol. Value tells a legacy device the number of octets in a legacy burst. |
|
Parity |
1 |
Parity bit in the L-SIG symbol. Valid L-SIG symbols have even parity for all bits excluding the tail bits. |
|
Tail |
6 |
Signal Tail bits of the L-SIG symbol. Normally set to 0. |
If there is no L-SIG symbol present, the fields display asterisks.
See Also
