Cisco Mesh Access Points Deployment Manual page 69

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