802.11be Physical Rates
What are physical rates in IEEE 802.11be?
Physical rates refer to the data transmission speeds at the physical layer, determined by modulation, coding, channel width, and spatial streams.
What is the maximum data rate supported by 802.11be?
802.11be supports theoretical physical rates exceeding 40 Gbps using advanced features like 320 MHz channels and 16 spatial streams.
How does 802.11be achieve such high data rates?
Through wider channels (up to 320 MHz), higher-order modulation (4096-QAM), more spatial streams, and multi-link operation (MLO).
What is 4096-QAM in 802.11be?
It’s a high-efficiency modulation scheme that allows encoding 12 bits per symbol, significantly increasing data throughput over previous standards.
What channel bandwidths are supported in 802.11be?
20, 40, 80, 160, and 320 MHz channels are supported, with 320 MHz enabling the highest physical layer rates.
What are spatial streams and how many does 802.11be support?
Spatial streams allow parallel data transmission. 802.11be supports up to 16 spatial streams, doubling the limit from Wi-Fi 6.
What is Multi-Link Operation (MLO) and how does it affect physical rates?
MLO enables simultaneous use of multiple bands/links, aggregating bandwidth and increasing physical data rates.
Are physical rates fixed in 802.11be?
No, devices dynamically adjust physical rates based on channel conditions using rate adaptation algorithms.
How do physical rates differ from throughput?
Physical rates represent raw PHY-layer speeds, while throughput reflects actual usable data after accounting for overhead and retransmissions.
Does 802.11be support OFDMA?
Yes, Orthogonal Frequency Division Multiple Access is supported and improves spectral efficiency and effective throughput.
How does 802.11be utilize beamforming to improve physical rates?
Beamforming focuses signals toward the receiver, improving signal strength and enabling use of higher modulation rates.
Can clients with fewer antennas use high physical rates?
Only to a limited extent; devices with more antennas and MIMO support can fully leverage higher physical rate capabilities.
What are Modulation and Coding Schemes (MCS) in 802.11be?
MCS index values represent combinations of modulation type, coding rate, and number of spatial streams, determining the PHY rate.
How does 802.11be maintain reliable high-speed transmissions?
Through adaptive modulation, error correction coding, and fast channel feedback mechanisms to select optimal transmission rates.
What is the impact of channel bonding in 802.11be?
Channel bonding combines multiple adjacent channels into a wider one (e.g., 320 MHz), dramatically boosting physical rates.
Is 802.11be backward compatible with earlier PHY rates?
Yes, it supports legacy rates for compatibility with older Wi-Fi devices, though advanced features may be disabled in such scenarios.
What determines the actual physical rate during a connection?
Factors like signal strength, interference, device capability, and current modulation/coding all influence the selected PHY rate.
How are physical rates calculated in 802.11be?
PHY rates are derived from parameters like MCS index, channel width, guard interval, and number of spatial streams using standard equations.
Does higher physical rate always mean better performance?
Not necessarily—higher rates may lead to more errors in poor channel conditions, reducing effective throughput. Rate adaptation balances this.
Where are the official physical rate tables for 802.11be published?
They are found in the IEEE 802.11be (EHT) standard documentation and Wi-Fi Alliance certification guidelines.
Topics in this section,
Modulation |
BW |
Tsc |
FSP=BW/Tsc |
Tdata=1/FSP |
GI (ns) |
Symbol (ns) |
1/Symbol |
Bits/Symbol |
Code rate |
Usable sc |
Rate (Mbps) |
|---|---|---|---|---|---|---|---|---|---|---|---|
BPSK |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
1 |
1/2 |
234 |
7.8 |
BPSK |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
1 |
3/4 |
234 |
11.7 |
QPSK |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
2 |
1/2 |
234 |
15.6 |
QPSK |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
2 |
3/4 |
234 |
23.4 |
16-QAM |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
4 |
1/2 |
234 |
31.2 |
16-QAM |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
4 |
3/4 |
234 |
46.8 |
64-QAM |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
6 |
2/3 |
234 |
41.6 |
64-QAM |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
6 |
3/4 |
234 |
46.8 |
256-QAM |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
8 |
3/4 |
234 |
62.4 |
256-QAM |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
8 |
5/6 |
234 |
78.0 |
1024-QAM |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
10 |
3/4 |
234 |
78.0 |
1024-QAM |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
10 |
5/6 |
234 |
97.5 |
4096-QAM |
20 |
256 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
12 |
3/4 |
234 |
93.6 |
4096-QAM |
20 |
256 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
12 |
5/6 |
234 |
117.0 |
BPSK |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
1 |
1/2 |
468 |
15.6 |
BPSK |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
1 |
3/4 |
468 |
23.4 |
QPSK |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
2 |
1/2 |
468 |
31.2 |
QPSK |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
2 |
3/4 |
468 |
46.8 |
16-QAM |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
4 |
1/2 |
468 |
62.4 |
16-QAM |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
4 |
3/4 |
468 |
93.6 |
64-QAM |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
6 |
2/3 |
468 |
83.2 |
64-QAM |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
6 |
3/4 |
468 |
93.6 |
256-QAM |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
8 |
3/4 |
468 |
124.8 |
256-QAM |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
8 |
5/6 |
468 |
156.0 |
1024-QAM |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
10 |
3/4 |
468 |
156.0 |
1024-QAM |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
10 |
5/6 |
468 |
195.0 |
4096-QAM |
40 |
512 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
12 |
3/4 |
468 |
187.2 |
4096-QAM |
40 |
512 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
12 |
5/6 |
468 |
234.0 |
BPSK |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
1 |
1/2 |
980 |
32.7 |
BPSK |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
1 |
3/4 |
980 |
49.1 |
QPSK |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
2 |
1/2 |
980 |
65.4 |
QPSK |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
2 |
3/4 |
980 |
98.1 |
16-QAM |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
4 |
1/2 |
980 |
130.8 |
16-QAM |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
4 |
3/4 |
980 |
196.2 |
64-QAM |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
6 |
2/3 |
980 |
174.5 |
64-QAM |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
6 |
3/4 |
980 |
196.2 |
256-QAM |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
8 |
3/4 |
980 |
261.6 |
256-QAM |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
8 |
5/6 |
980 |
326.9 |
1024-QAM |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
10 |
3/4 |
980 |
326.9 |
1024-QAM |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
10 |
5/6 |
980 |
408.6 |
4096-QAM |
80 |
1024 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
12 |
3/4 |
980 |
374.4 |
4096-QAM |
80 |
1024 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
12 |
5/6 |
980 |
468.0 |
BPSK |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
1 |
1/2 |
1960 |
65.4 |
BPSK |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
1 |
3/4 |
1960 |
98.1 |
QPSK |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
2 |
1/2 |
1960 |
130.8 |
QPSK |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
2 |
3/4 |
1960 |
196.2 |
16-QAM |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
4 |
1/2 |
1960 |
261.6 |
16-QAM |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
4 |
3/4 |
1960 |
392.4 |
64-QAM |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
6 |
2/3 |
1960 |
349.0 |
64-QAM |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
6 |
3/4 |
1960 |
392.4 |
256-QAM |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
8 |
3/4 |
1960 |
523.2 |
256-QAM |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
8 |
5/6 |
1960 |
653.8 |
1024-QAM |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
10 |
3/4 |
1960 |
653.8 |
1024-QAM |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
10 |
5/6 |
1960 |
817.2 |
4096-QAM |
160 |
2048 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
12 |
3/4 |
1960 |
748.8 |
4096-QAM |
160 |
2048 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
12 |
5/6 |
1960 |
937.5 |
BPSK |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
1 |
1/2 |
3920 |
130.8 |
BPSK |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
1 |
3/4 |
3920 |
196.2 |
QPSK |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
2 |
1/2 |
3920 |
261.6 |
QPSK |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
2 |
3/4 |
3920 |
392.4 |
16-QAM |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
4 |
1/2 |
3920 |
523.2 |
16-QAM |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
4 |
3/4 |
3920 |
784.8 |
64-QAM |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
6 |
2/3 |
3920 |
698.0 |
64-QAM |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
6 |
3/4 |
3920 |
784.8 |
256-QAM |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
8 |
3/4 |
3920 |
1046.4 |
256-QAM |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
8 |
5/6 |
3920 |
1307.6 |
1024-QAM |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
10 |
3/4 |
3920 |
1307.6 |
1024-QAM |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
10 |
5/6 |
3920 |
1634.4 |
4096-QAM |
320 |
4096 |
78.125 |
12.8 |
800 |
13.6 |
0.0735 |
12 |
3/4 |
3920 |
1497.6 |
4096-QAM |
320 |
4096 |
78.125 |
12.8 |
400 |
13.2 |
0.0758 |
12 |
5/6 |
3920 |
1875.0 |
Reference links