4.9 Ghz Antenna - ABB Tropos 4310-XA Installation Manual

Attenuation with External Antennas
If external antennas are used, it is necessary to adjust the transmit power attenuation to provide
the correct power level for the router. Use the following formulas to compute the required
attenuation level:
Gain' (dBi) = Antenna Gain (dBi) - Cable Loss (dB)
802.11b/g:
Tx Antenna Setting (dB) =

4.9 GHz Antenna

The information in this section applies to the Tropos 4319-XA router.
Note
Operation in the 4.9 GHz band requires an FCC license. The following eligibility rules are specified in Part
90.1203 of the FCC rules:
• Entities providing public safety services as defined under section 90.523 are eligible to hold an FCC
license for systems operating in the 4940-4990 MHz band. All of the requirements and conditions set
forth in that section also govern authorizations in the 4940-4990 MHz band.
• 4.9 GHz band licensees may enter into sharing agreements or other arrangements for use of the
spectrum with entities that do not meet these eligibility requirements. However, all applications in the
band are limited to operations in support of public safety.
Note
To reduce potential radio interference to other users, the antenna type and its gain should be so chosen
that the Effective Isotropic Radiated Power (EIRP) is not more than that permitted for successful
communication.
Table 11 802.11a Antenna Configurations for Public Safety (4940-4990 MHz)
Antenna
9.0dBi omni, magnetic
mount
Tropos Mobile Mesh Router Installation Guide Models 4310-XA and 4319-XA
0
Gain' - 7
Channel
Bandwidth /
Ordering Operating
Number Frequency (MHz)
AN090049 20
4950 - 4980
if Gain' < 7 dBi
if Gain' > 7dBi
Tx
Measured Attenuation
Conducted Software
Power (dBm) Setting (dB)
20.0
Chapter 3
Approximate
EIRP (dBm)
4 29.0
17