User's Manual

3. Pre-Installation Procedures 3-7

3.6.1 5.8 GHz Band

For fixed point-to-point applications in the United States the maximum EIRP (Effective

Isotropic Radiated Power) is unlimited when using directional antennas in accordance

with FCC part 15.247b(3). The EVENT 5800 5800 can be operated at its maximum output

power, +23 dBm, for maximum system gain. For external antennas, EIRP is calculated as

follows:

EIRP(avg) dBm = External Antenna Gain (dBi) + 23 dBm

For internal antenna (23 dBi) EIRP is calculated as follows:

EIRP(avg) = 46 dBm

3.6.2 5.3 GHz Band

In the 5.3 GHz U-NII band the peak EIRP (Effective Isotropic Radiated Power) is limited

to +30 dBm at the antenna for bandwidths above 20 MHz and is reduced for narrower

bandwidths in accordance with FCC part 15.407a(3).

The installer is responsible during set up of transmit power to not exceed FCC limits on

transmission power. These maximum power levels are provided in Table 3-3 for both

internal antenna and external antenna configurations.

Note that though regulatory limits are stated in terms of peak power, the system

transmit power levels are calibrated as averaged power readings. Average power is used

for link calculations. Therefore the levels provided in the following table is average power

levels that have been certified to correspond with the maximum peak EIRP allowed.

3.6.2.1 Internal Antenna

Table 3-3 indicates the maximum average transmit power setting that may be selected

EVENT 5800 5300 with internal (23 dBi) antenna.

The number of supported channels per band (low band or high band) is shown in the link

configuration wizard. The greater number of channels supported the lower the emission

bandwidth for each channel.

For link budget,

EIRP(Avg) = 23 dBi + Tx Power Setting (dBm).

3.6.2.2 External Antenna

When using external antennas with gains greater than 23 dBi, the transmit power must

be reduced in dB from that given in Table 3-3 by the antenna gain difference above 23

dBi for the mode that is being used.

For example, using a 6 foot dish antenna with 37 dBi gain, the output power would be

dropped by:

Antenna Gain (External) – 23 dBi = Antenna Gain Difference

Example:

37.6 dBi – 23 dBi = 14.6 dB

For mode 100FE1 (single channel configuration with 30MHz emission bandwidth) the

power would be lowered from:

Tx Power (Internal Antenna) – Antenna Gain Difference = Tx Power (External

Ant)

Example: