802.11i Physical Rates
What are the physical rates supported in IEEE 802.11i?
802.11i supports the same physical rates as the underlying 802.11 standard it secures, e.g., 802.11a/g/n rates.
Does 802.11i define new physical rates?
No, 802.11i focuses on security; physical rates are defined by the base standard (e.g., 802.11a/g/n).
How does encryption affect effective throughput?
Encryption overhead can slightly reduce net throughput but physical rates remain unchanged.
Are rate adaptation algorithms impacted by 802.11i?
Rate adaptation continues normally but must account for processing delays due to encryption.
What modulation schemes are used with 802.11i?
Modulation schemes (e.g., OFDM for 802.11a) remain as specified in the base standard.
Does 802.11i security impact latency at physical rates?
Minor increases in latency may occur due to encryption/decryption processing.
Are all physical rates equally supported with 802.11i?
Yes, 802.11i supports all rates of the underlying standard without restriction.
Does 802.11i support high-throughput modes like 802.11n/ac?
Yes, security mechanisms are applicable to all newer PHY rates including HT and VHT.
How do physical rates influence security handshake duration?
Higher rates reduce handshake times by speeding frame exchanges.
Can physical layer errors affect 802.11i security?
Yes, errors may cause handshake retries or rekeying, impacting secure communication.
How is backward compatibility ensured at physical rates?
Devices can fallback to lower physical rates to maintain secure links under poor conditions.
Do security features affect channel bonding or aggregation?
No, 802.11i security works with channel bonding and frame aggregation as defined in PHY.
Are there power consumption implications at various physical rates?
Higher rates may increase power use, with 802.11i security adding slight overhead.
How do physical rates interact with QoS in 802.11i?
QoS prioritization is preserved across all physical rates secured by 802.11i.
What is the impact of physical rate on multicast and broadcast in 802.11i?
Multicast/broadcast frames use lower rates to improve reliability, secured by 802.11i.
Are physical rates standardized across different countries for 802.11i?
Yes, regional regulations dictate allowed rates and channels; 802.11i works within these.
Does 802.11i impact the use of legacy rates?
Legacy rates are supported to maintain compatibility with older devices using security.
How do physical rates affect the overall security performance?
Higher rates improve responsiveness but require efficient encryption processing to keep pace.
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