User's Manual

Summit Manufacturing Utility (SMU) Guide 05/13/09
Summit Data Communications, Inc.
7 CONFIDENTIAL
2.2.5 BG Max Antenna Adjust and A Max Antenna Adjust
The last two card settings provides for an adjustment to the radio’s transmit power to accommodate a 2.4
GHz (802.11b/g) antenna, a 5 GHz (802.11a) antenna, or a dual-band antenna with a gain greater than 0
dBm. The values for each of these settings, “BG Max antenna adjust” and “A Max antenna adjust”, is the
degree of antenna attenuation expressed as a percentage of dBm, not milliwatts (mW), with the
percentage based on a TELEC 50 mW test. On the next page is a table of popular dBm values and their
corresponding mW values.
Here is an example: In ETSI, to ensure that the maximum 802.11b transmit power is 50 mW, use 94%:
94% x 18 dBm = 16.92 dBm = 50 mW
The default value is “100%”.
dBm mW dBm mW dBm mW
20 100 15 31.6 10 10
19 79.4 14 25.1 8 6.3
18 63.1 13 20 6 4
17 50.1 12 15.8 3 2
16 39.8 11 12.6 0 1
Beginning with V1.03.23 of Summit software, the transmit power (Tx Power) value on the SCU Status
window accounts for the transmit power adjustment set in SMU. As a result, the displayed value is the
true transmit power of the Summit radio. In previous releases, the Status window displayed the transmit
power without the adjustment, because SCU assumed that the antenna provided a gain that compensated
for the adjustment. With previous releases, therefore, the displayed value was an estimate of EIRP and
not a true radio transmit power value.