802.11d Physical Rates
What are physical data rates in IEEE 802.11d?
Physical data rates refer to the raw bit rates at which data is transmitted over the wireless medium.
Does 802.11d define new physical rates?
No, 802.11d extends existing 802.11 standards by adding country-specific regulatory information but does not define new physical rates itself.
Which frequency bands does 802.11d support for physical rates?
802.11d supports both 2.4 GHz and 5 GHz bands, enabling operation in multiple regulatory domains.
How does 802.11d affect available physical rates?
It enables devices to use country-specific allowed channels and power levels, indirectly influencing achievable data rates.
Are data rates in 802.11d fixed or adaptive?
Data rates can be adaptive, changing based on signal quality and regulatory constraints.
What are common physical data rates supported in 802.11d networks?
Typical rates include 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, and 54 Mbps depending on modulation and band.
Does 802.11d support OFDM rates?
Yes, as it builds on 802.11a/g/n standards, 802.11d supports OFDM rates for higher throughput.
Can 802.11d devices operate at lower physical rates?
Yes, they can use lower rates like 1 or 2 Mbps for better range or compatibility.
How are physical rates negotiated in 802.11d?
Devices negotiate rates during association and can switch dynamically based on link quality.
Does 802.11d impact rate adaptation algorithms?
Not directly, but regulatory domain info can influence available channels and power, indirectly affecting rate choices.
Are the physical rates in 802.11d different in 5 GHz band vs 2.4 GHz?
Physical rates depend on the underlying PHY (like 802.11a/g); 5 GHz generally supports OFDM rates while 2.4 GHz supports both DSSS and OFDM.
What modulation schemes determine physical rates in 802.11d?
Modulations include BPSK, QPSK, 16-QAM, and 64-QAM, affecting the achievable rates.
How does channel width affect physical rates in 802.11d?
Wider channels (e.g., 40 MHz) allow higher data rates but 802.11d itself does not define channel width—it follows underlying standards.
Are physical rates in 802.11d limited by regulations?
Yes, regulations in each country limit transmit power and channels, which can limit maximum physical rates.
Does 802.11d support legacy physical rates?
Yes, it maintains compatibility with legacy rates from 802.11b/g/a as per the region’s rules.
How does 802.11d handle physical rate changes when roaming?
It updates regulatory info to comply with new country rules, which can affect available rates.
Can 802.11d devices dynamically switch physical rates?
Yes, rate adaptation mechanisms allow switching rates for optimal throughput and reliability.
Is the maximum physical rate in 802.11d fixed?
No, it varies depending on underlying PHY (802.11a/g/n) and regional constraints.
Topics in this section,
Modulation |
BW |
Tsc |
FSP=BW/Tsc |
Tdata=1/FSP |
GI=Tdata/4 |
Symbol=Tdata+GI |
1/Symbol |
Bits/Symbol |
Code rate |
Usable sc |
Rate |
|---|---|---|---|---|---|---|---|---|---|---|---|
BPSK |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
1 |
1/2 |
48 |
1.5 |
BPSK |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
1 |
3/4 |
48 |
2.25 |
QPSK |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
2 |
1/2 |
48 |
3 |
QPSK |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
2 |
3/4 |
48 |
4.5 |
16-QAM |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
4 |
1/2 |
48 |
6 |
16-QAM |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
4 |
3/4 |
48 |
9 |
64-QAM |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
6 |
2/3 |
48 |
12 |
64-QAM |
5 |
64 |
78.125 |
12.8 |
3.2 |
16 |
0.0625 |
6 |
3/4 |
48 |
13.5 |
BPSK |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
1 |
1/2 |
48 |
3 |
BPSK |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
1 |
3/4 |
48 |
4.5 |
QPSK |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
2 |
1/2 |
48 |
6 |
QPSK |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
2 |
3/4 |
48 |
9 |
16-QAM |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
4 |
1/2 |
48 |
12 |
16-QAM |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
4 |
3/4 |
48 |
18 |
64-QAM |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
6 |
2/3 |
48 |
24 |
64-QAM |
10 |
64 |
156.25 |
6.4 |
1.6 |
8 |
0.125 |
6 |
3/4 |
48 |
27 |
BPSK |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
1 |
1/2 |
48 |
6 |
BPSK |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
1 |
3/4 |
48 |
9 |
QPSK |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
2 |
1/2 |
48 |
12 |
QPSK |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
2 |
3/4 |
48 |
18 |
16-QAM |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
4 |
1/2 |
48 |
24 |
16-QAM |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
4 |
3/4 |
48 |
36 |
64-QAM |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
6 |
2/3 |
48 |
48 |
64-QAM |
20 |
64 |
312.5 |
3.2 |
0.8 |
4 |
0.25 |
6 |
3/4 |
48 |
54 |
Reference links