UHR PPDU Structure

WLAN Toolbox™ enables you to model various 802.11™ versions. Each version of the standard uses a different format for data transmission.

Packet Definition

IEEE® 802.11is a packet-based protocol, which means that it transmits data in discrete units. The units are called packets or physical layer protocol data units (PPDUs). Each PPDU contains preamble and data fields. The preamble fields contain the transmission vector format information. The data field contains the user payload and higher layer headers, such as medium access control (MAC) fields and cyclic redundancy check (CRC). The transmission vector format and the PPDU structure vary between 802.11 versions. The transmission vector (TXVECTOR) format parameter is classified as:

  • UHR to specify an ultra high-reliability (UHR) physical layer (PHY) implementation.

    • UHR refers to fields formatted for association with 802.11bn™ (Wi-Fi®8) data. IEEE P802.11bn [1] defines and describes the UHR PHY layer and PPDU.

Supported 802.11 Versions

The table shows 802.11 versions that WLAN Toolbox supports, along with the supported TXVECTOR options and associated modulation formats.

802.11 Version

Transmission Vector Format

Modulation Format

Bandwidth/MHz
802.11bn (Wi-Fi 8)UHROFDMA

20, 40, 80, 160, 320

802.11be™ (Wi-Fi 7)

EHT

OFDMA

20, 40, 80, 160, 320

802.11ba™WURMC-OOK20, 40, 80

802.11ax™ (Wi-Fi 6)

HE

OFDMA

20, 40, 80, 160

802.11ad™

DMG

Single carrier and OFDM

2640

802.11ah™

S1G

OFDM only

1, 2, 4, 8, 16

802.11ac™ (Wi-Fi 5)

VHT

OFDM only

20, 40, 80, 160

802.11n™ (Wi-Fi 4)

HT

OFDM only

20, 40

802.11g™

Non-HT

OFDM

20

Non-HT

DSSS/CCK

11

802.11p™

Non-HT

OFDM only

5, 10

802.11j™

Non-HT

OFDM only

10

802.11a™

Non-HT

OFDM only

5, 10, 20

802.11b™

Non-HT

DSSS/CCK

11

Field Structure

For UHR, there are three transmission modes: UHR multi-user (UHR MU), UHR trigger-based (UHR TB), and UHR enhanced long range (ELR).

The field structure for UHR PPDUs consists of preamble and data portions. The legacy preamble fields (L-STF, L-LTF, and L-SIG) are present in UHR, EHT, WUR, HE, VHT, and non-HT PPDUs. The RL-SIG and PE fields are common to UHR, EHT, and HE PPDUs. This table summarizes the structure of a UHR MU PPDU.

PPDU Field Abbreviation

Description

Duration (µs)

L-STF

Non-HT Short Training field

8

L-LTF

Non-HT Long Training field

8

L-SIG

Non-HT Signal field

4

RL-SIG

Repeated Non-HT Signal field

4

U-SIG

Universal Signal field

8: 4 µs per OFDM symbol

UHR-SIG

UHR Signal field

Variable: 4 µs per OFDM symbol

UHR-STF

UHR Short Training field

4

UHR-LTF

UHR Long Training field

Variable: depends on the guard interval and UHR-LTF type

UHR-Data

Data field carrying the PSDUs

Variable: depends on the PSDU lengths

PE

Packet Extension field

0, 4, 8, 12, 16, or 20

The structure of a UHR TB PPDU is the same, except that the UHR-SIG field is not present and the UHR-STF has double the duration. For more information, see Section 38.3.4 of IEEE P802.11bn [1].

This table summarizes the structure of a UHR ELR PPDU.

PPDU Field Abbreviation

Description

Duration (µs)

L-STF

Non-HT Short Training field

8

L-LTF

Non-HT Long Training field

8

L-SIG

Non-HT Signal field

4

RL-SIG

Repeated Non-HT Signal field

4

U-SIG

Universal Signal field

8: 4 µs per OFDM symbol

ELR-MARK

ELR MARK field

8: 4 µs per OFDM symbol

UHR-STF

UHR Short Training field

4

UHR-LTF

UHR Long Training field

16: 8 µs per OFDM symbol

ELR-SIG

ELR Signal field

28.8: 14.4 µs per OFDM symbol

UHR-Data

Data field carrying the PSDUs

Variable: depends on the PSDU lengths

PE

Packet Extension field

8

References

[1] IEEE P802.11bn/D0.1. “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. Amendment 6: Enhancements for ultra high reliability (UHR).” Draft Standard for Information Technology — Telecommunications and Information Exchange between Systems — Local and Metropolitan Area Networks — Specific Requirements

See Also

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