802.11ai Physical Rates
What are physical rates in IEEE 802.11ai?
Physical rates refer to the data transmission speeds defined at the PHY layer used by 802.11ai devices.
Does 802.11ai define new physical rates?
No, 802.11ai uses physical rates defined by underlying PHY standards like 802.11ac or 802.11ax.
How are physical rates selected in 802.11ai networks?
They are chosen dynamically based on link conditions, signal quality, and network management algorithms.
Why is physical rate adaptation important in 802.11ai?
To optimize throughput and reliability by adjusting transmission speed to current channel conditions.
How does 802.11ai assist physical rate control?
It provides enhanced network management information to help devices choose appropriate rates.
Are legacy rates supported in 802.11ai?
Yes, backward compatibility ensures support for legacy physical rates where needed.
What PHY modulation schemes affect physical rates in 802.11ai?
Modulations like QAM, OFDM, and DSSS from base PHY standards determine achievable rates.
Does 802.11ai support multi-user physical rates?
Yes, it works with multi-user MIMO and OFDMA techniques defined in underlying PHY layers.
How does physical rate impact power consumption in 802.11ai devices?
Higher rates may consume more power; rate adaptation helps balance speed and energy efficiency.
Can physical rates be different for uplink and downlink?
Yes, rates can be independently selected for uplink and downlink based on link quality.
How is physical rate information reported in 802.11ai?
Devices report link metrics to access points, assisting rate control and network management.
Do physical rates affect latency in 802.11ai?
Yes, higher rates generally reduce transmission time and lower latency.
What is the role of PHY layer feedback in physical rate selection?
Feedback like SNR and error rates guide dynamic adaptation to optimize performance.
Is physical rate control centralized or distributed in 802.11ai?
It can be both; APs and clients collaborate using network-assisted mechanisms.
Can 802.11ai physical rates support dense network environments?
Yes, efficient rate adaptation helps maintain throughput in crowded Wi-Fi deployments.
How do interference and noise impact physical rates?
They degrade signal quality, causing devices to lower rates to maintain connection stability.
Are physical rates standardized internationally in 802.11ai?
Yes, 802.11ai follows international IEEE standards ensuring global compatibility.
How can users monitor physical rates in their networks?
Many access points provide rate statistics via management interfaces or apps.
Where can I find detailed technical specs on 802.11ai physical rates?
IEEE 802.11ai standard documents and PHY layer specifications in 802.11ac/ax provide details.
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