Fonte: clubedohardware.com.br
A maioria dos fabricantes de radios usa dBm – potencia em decibéis – (abbreviation for the power ratio in decibels (dB)) como medida de potencia de sinal.
Alguns poucos usam RSSI -potencia em porcentagem (received signal strength indication (RSSI)) como forma de medir a potencia do sinal.
Neste site você encontra a forma de calcular e comparar as duas formas de medir a potencia dos rádios
http://www.wildpackets.com/elements/whitepapers/Converting_Signal_Strength.pdf
Veja a tabela comparativa RSSI x dBm
Conversion for Cisco
Cisco has the most granular dBm lookup table.
RSSI_Max = 100
Convert % to RSSI and lookup the result in the following table. The RSSI is on the left,
and the corresponding dBm value (a negative number) is on the right.
0 = -113
1 = -112
2 = -111
3 = -110
4 = -109
5 = -108
6 = -107
7 = -106
8 = -105
9 = -104
10 = -103
11 = -102
12 = -101
13 = -99
14 = -98
15 = -97
16 = -96
17 = -95
18 = -94
19 = -93
20 = -92
21 = -91
22 = -90
23 = -89
24 = -88
25 = -87
26 = -86
27 = -85
28 = -84
29 = -83
30 = -82
31 = -81
32 = -80
33 = -79
34 = -78
35 = -77
36 = -75
37 = -74
38 = -73
39 = -72
40 = -70
41 = -69
42 = -68
43 = -67
44 = -65
45 = -64
46 = -63
47 = -62
48 = -60
49 = -59
50 = -58
51 = -56
52 = -55
53 = -53
54 = -52
55 = -50
56 = -50
57 = -49
58 = -48
59 = -48
60 = -47
61 = -46
62 = -45
63 = -44
64 = -44
65 = -43
66 = -42
67 = -42
68 = -41
69 = -40
70 = -39
71 = -38
72 = -37
73 = -35
74 = -34
75 = -33
76 = -32
77 = -30
78 = -29
79 = -28
80 = -27
81 = -25
82 = -24
83 = -23
84 = -22
85 = -20
86 = -19
87 = -18
88 = -17
89 = -16
90 = -15
91 = -14
92 = -13
93 = -12
94 = -10
95 = -10
96 = -10
97 = -10
98 = -10
99 = -10
100 = -10
Notice that this gives a range of –10dBm to –113dBm. Bearing in mind that a Cisco card
will have a Receive Sensitivity of –96dBm at its lowest, it is impossible to obtain an RSSI
value of less than 16. Note, also, that all RSSI values greater than 93 are assigned
–10dBm, and that there are multiple places in the table where two adjacent RSSI values
are assigned the same dBm value.