802.11bn Physical Rates
What is the maximum physical data rate in 802.11bn?
The maximum theoretical PHY rate is 600 Mbps using 4 spatial streams, 40 MHz channel bandwidth, and short guard interval, while maintaining backward compatibility.
What legacy physical rates are supported in 802.11b?
1, 2, 5.5, and 11 Mbps using DSSS and CCK modulation in 2.4 GHz band.
How does 802.11bn support backward compatibility with 802.11b devices?
By using Mixed Mode preambles and including legacy fields, it allows coexistence but reduces maximum throughput.
Can 802.11bn devices fall back to 802.11b physical rates?
Yes, devices automatically fall back to legacy rates to maintain compatibility with b-only clients.
What is the impact of 802.11b clients on 802.11bn network throughput?
The presence of 802.11b clients slows the entire network due to longer preambles and slower transmission rates.
What channel bandwidths are supported in 802.11bn?
Both 20 MHz and 40 MHz channel widths are supported, but 40 MHz is less common in mixed mode due to interference concerns.
How many spatial streams are supported in 802.11bn?
Up to 4 spatial streams like 802.11n, but real-world deployments often use fewer.
What modulation schemes does 802.11bn use for 802.11n packets?
OFDM with BPSK, QPSK, 16-QAM, and 64-QAM depending on MCS index and channel conditions.
What modulation does 802.11b use?
DSSS with DBPSK and DQPSK for 1 and 2 Mbps; CCK for 5.5 and 11 Mbps.
How does the guard interval affect physical rates in 802.11bn?
Using short guard interval (400 ns) boosts PHY rates by approximately 10%, but it is sometimes disabled for compatibility.
Are MCS indexes used in 802.11bn?
Yes, MCS indexes define modulation, coding rate, spatial streams, and guard intervals for the 802.11n portion.
What is the lowest physical rate in 802.11bn?
1 Mbps from 802.11b legacy rates.
Does 802.11bn support channel bonding?
Yes, 40 MHz channel bonding is supported but may be limited in mixed environments due to legacy interference.
How is the physical rate selected in 802.11bn?
Devices adaptively select the highest possible rate based on signal quality, supported MCS, and coexistence requirements.
What effect does the presence of 802.11b devices have on short guard interval usage?
It may force the network to use a longer guard interval to maintain compatibility, reducing peak PHY rates.
How do 802.11bn devices handle collisions with 802.11b clients?
Mixed mode uses protection mechanisms like RTS/CTS to minimize collisions and maintain throughput.
What is the typical real-world maximum throughput for 802.11bn?
Usually around 100–200 Mbps due to overhead and legacy client presence.
Are there any interoperability issues with 802.11bn physical rates?
Sometimes, older 802.11b devices can cause network slowdown and increase latency.
Can 802.11bn achieve the same rates as pure 802.11n networks?
No, due to legacy device overhead and protection mechanisms, maximum rates are generally lower.
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