9
1-4 Calculate Transmit Power
In order to obtain the best performance of booster and system, user must
calculate the transmission power to meet the booster technical
requirement and FCC regulations(See Appendix B). It is advised that the
user follows the calculation below:
1.
Converter power of the access point from milliwatts to dBm.
Note
: dBm = 10 * Log(milliwatts)
2.
Determine the attenuation of cable(please refer to manufacturer’s
specifications)
Note
: Suggest the cable loss between booster and DC injector should not
exceed 10 dBm generally.
Table A – Typical Cable Attenuation Values
Cable Type
Attenuation dB/100ft @2.4GHz
RG-142 21
LMR200 16.5
LMR400 6.6
LMR600 4.4
LMR900 2.92
Belden 9913
7.1
Note: Values are approximate.
3.
Calculate the actual power of booster in the pole as follow:
Access point Power(dBm) – Cable Loss(dBm) – Misc. Loss = Input
Signal Level(dBm)
Note
: Misc. Loss means loss of connector, adapter and DC injector and
estimates to be around 2 dB.
4.
If the input signal level exceeds the max. Transmitter Input Power or
fails to meet the min. Transmitter Input Power of booster, the booster
can’t identify the input signal. Under this circumstance, user should
adjust the input signal level to fit the requirement such as using an
attenuation pad or a higher loss cable and vice versa.
