WUR PPDU Structure

IEEE^® 802.11™¹ is a packet-based protocol. Each packet, also called a physical layer protocol data unit (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:

WUR to specify a wake-up radio (WUR) physical layer (PHY) implementation.
- WUR refers to fields formatted for association with 802.11ba™ data. Reference [1] defines and describes the WUR PHY layer and PPDU.
- For WUR, the TXVECTOR parameters, as defined in Table 30-1 of [1], determine the structure of PPDUs transmitted by a WUR station (STA).

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
802.11b™	non-HT	DSSS/CCK	11
802.11a™	non-HT	OFDM only	5, 10, 20
802.11j™	non-HT	OFDM only	10
802.11p™	non-HT	OFDM only	5, 10
802.11g™	non-HT	OFDM	20
802.11g™	non-HT	DSSS/CCK	11
802.11n™ (Wi-Fi 4)	HT_MF, Non-HT	OFDM only	20, 40
802.11ac™ (Wi-Fi 5)	VHT, HT_MF, Non-HT	OFDM only	20, 40, 80, 160
802.11ah™	S1G	OFDM only	1, 2, 4, 8, 16
802.11ad™	DMG	Single Carrier and OFDM	2640
802.11ax™ (Wi-Fi 6)	HE	OFDMA	20, 40, 80, 160
802.11ba	WUR	MC-OOK	20, 40, 80
802.11be™ (Wi-Fi 7)	EHT	OFDMA	20, 40, 80, 160, 320

For WUR, there are two transmission modes: WUR Basic and WUR FDMA. The wlanWURConfig configuration object enables you to create PPDUs and waveforms for both of them. WUR Basic transmissions must have a bandwidth of 20 MHz. WUR FDMA transmissions must have a bandwidth of 40 or 80 MHz.

The field structure for WUR PPDUs consists of preamble and data portions. This table summarizes the structure of a WUR Basic 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
BPSK-Mark1	A BPSK-modulated OFDM symbol	4
BPSK-Mark2	A BPSK-modulated OFDM symbol	4
WUR-Sync	WUR Synchronization field	64 or 128
WUR-Data	WUR Data field	Variable

The preamble consists of all the fields up to and including the BPSK-Mark2 field.

WUR FDMA PPDUs are divided into 20 MHz subchannels. Each subchannel has its own preamble. The preamble of each subchannel has the same structure as the preamble of a WUR Basic PPDU. Within a PPDU, each 20 MHz subchannel has the same values in its preamble fields. The values of the two non-preamble fields can differ between subchannels.

For more information, see Sections 30.3.2 and 30.3.3 of [1].

References

[1] IEEE Std 802.11ba-2021. “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. Amendment 3: Wake-Up Radio Operation.” IEEE Standard for Information Technology — Telecommunications and Information Exchange between Systems. Local and Metropolitan Area Networks — Specific Requirements.