Microwave Data Systems MDS entraNET 2400 Especificaciones descargar pdf (Pagina 166)

156 GE MDS entraNET Reference Manual 05-4055A01, Rev. D

6.2 HOW MUCH OUTPUT POWER CAN

BE USED?

(U.S.A. and Canada, 900 MHz systems)

900 MHz transceivers are normally supplied from the factory set for +30

dBm (1 Watt) RF power output; this is the maximum transmitter output

power allowed under FCC and Industry Canada rules. The power must

be decreased from this level if the antenna system gain exceeds 6 dBi.

The allowable level is dependent on the antenna gain, feedline loss, and

the transmitter output power setting.

NOTE: In regions where ETSI standards apply, the maximum allow-

able RF output is generally limited to 100 mW (+20 dBm) on

2400 MHz. License-free operation on 900 MHz is not

permitted. For more information, see HOW MUCH OUTPUT

POWER CAN BE USED? (ETSI 2400 MHz systems) on

Page 158.

6.2.1 Calculating System Gain

To determine the maximum allowable power setting of the radio, per-

form the following steps:

1. Determine the antenna system gain by subtracting the feedline loss

(in dB) from the antenna gain (in dBi). For example, if the antenna

gain is 10 dBi, and the feedline loss is 2 dB, the antenna system gain

is 8 dB.

2. Subtract the antenna system gain from 36 dBm (the maximum

allowable EIRP). The result indicates the maximum transmitter

power (in dBm) allowed under the rules. In the example above, this

is 28 dBm.

3. If the maximum transmitter power allowed is less than 30 dBm,

reduce the transmit power accordingly using the radio menu system

(Main Menu>Radio Configuration>RF Output Power Setpoint), or introduce

additional feedline loss. The EIRP of the antenna system should

never exceed 36 dBi.

For convenience, Table 6-4 lists several antenna system gains and

shows the maximum allowable power setting of the radio. Note that a

1 2 ... 161 162 163 164 165 166 167 168 169 170 171 ... 219 220

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Microwave Data Systems MDS entraNET 2400 Especificaciones Pagina 166