802.11ax Physical Rates
What is the range of physical data rates supported by IEEE 802.11ax?
802.11ax supports data rates from as low as 0.3 Mbps up to 9.6 Gbps depending on channel width and MCS.
What modulation schemes are used in 802.11ax physical rates?
Uses OFDMA with modulation types including BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, and optional 1024-QAM.
How does channel bandwidth affect physical rates in 802.11ax?
Wider channels (20, 40, 80, 160 MHz) allow more data to be transmitted simultaneously, increasing max rates.
What is MCS in the context of 802.11ax physical rates?
Modulation and Coding Scheme defines combinations of modulation type and error correction rate affecting throughput.
Does 802.11ax support multi-user transmissions?
Yes, physical rates reflect multi-user OFDMA and MU-MIMO capabilities for simultaneous transmissions.
What is the highest modulation order in 802.11ax?
1024-QAM (Quadrature Amplitude Modulation), allowing higher data rates than previous standards.
How does 1024-QAM improve data rates?
It encodes more bits per symbol (10 bits vs 8 bits for 256-QAM), boosting throughput in good signal conditions.
What role do spatial streams play in physical rates?
Multiple spatial streams allow parallel data transmission via MU-MIMO, multiplying throughput.
How many spatial streams does 802.11ax support?
Up to 8 spatial streams for both uplink and downlink.
How does OFDMA affect physical rates?
OFDMA divides channels into smaller Resource Units, allowing efficient simultaneous transmissions to multiple users.
Can physical rates adapt dynamically in 802.11ax?
Yes, rate adaptation algorithms select MCS and resource allocation based on real-time channel conditions.
What channel widths does 802.11ax support?
20 MHz, 40 MHz, 80 MHz, 160 MHz, and optionally 80+80 MHz non-contiguous bonding.
How does 160 MHz channel width influence physical rates?
It doubles the throughput compared to 80 MHz channels, reaching peak data rates near 9.6 Gbps.
Does 802.11ax physical rate support uplink multi-user?
Yes, uplink OFDMA and MU-MIMO improve network efficiency by allowing multiple clients to transmit simultaneously.
What is the minimum physical rate in 802.11ax?
Around 0.3 Mbps using BPSK with a low coding rate, suitable for weak signal conditions.
How does 802.11ax handle interference affecting rates?
Uses spatial reuse and enhanced coding to maintain reliable connections at higher rates despite interference.
Are physical rates backward compatible in 802.11ax?
Yes, it supports legacy rates for interoperability with older Wi-Fi devices.
Where can I find detailed 802.11ax physical rates tables?
In the IEEE 802.11ax standard documentation and Wi-Fi Alliance technical resources.
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 |
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 |
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 |
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 |
Reference links