Minimum Required
LinkSNR (dB)
Fade Margin =
Minimum SNR (dB) +
802.11n Date Rate (Mbps)
15
9
6
9
16
9
7
12
18
9
9
18
22
9
13
24
26
9
17
36
• If we take into account the effect of MRC for calculating Minimum Required Link SNR.
Table 16:
Required LinkSNR Calculations for 802.11a/g, on page 53
shows the required LinkSNR for 802.11a/g
(2.4 GHz and 5 GHz) for AP1552 and 1522 with 3 Rx antennas (MRC gain).
LinkSNR = Minimum SNR - MRC + Fade Margin (9 dB)
Table 16: Required LinkSNR Calculations for 802.11a/g
Required Link
SNR (dB)
Fade Margin
(dB)
MRC Gain from
3 RXs (dB)
Minimum SNR
(dB)
Modulation
802.11a/g MCS
(Mbps)
9.3
9
4.7
5
BPSK 1/2
6
10.3
9
4.7
6
BPSK 3/4
9
11.3
9
4.7
7
QPSK 1/2
12
13.3
9
4.7
9
QPSK 3/4
18
17.3
9
4.7
13
16QAM 1/2
24
21.3
9
4.7
17
16QAM 3/4
36
24.3
9
4.7
20
64QAM 2/3
48
26.3
9
4.7
22
64QAM 3/4
54
If we consider only 802.11n rates, then
Table 17: Requirements for LinkSNR with AP1552 for 2.4 and 5
GHz, on page 54
shows LinkSNR requirements with AP1552 for 2.4 and 5 GHz.
Cisco Mesh Access Points, Design and Deployment Guide, Release 7.3
OL-27593-01
53
Design Considerations
Wireless Backhaul Data Rate