User's Manual

• The Ethernet switch port to which the V3000W W-CMTS is connected must be
optioned to 100 Mbps
, Full Duplex, No Auto-Negotiate.
5.4.3.1 Upconverter (Internal or external)
• 75 ohm type F female connectors
• Input signal frequency 44 MHz; level range +38 dBmV to +45 dBmV.
• Output signal frequency 477 through 577 MHz; maximum signal level +60 dBmV.
5.5 System Level-Setting Notes
5.5.1 General
The ARCell base station and subscriber transmitters are designed for linear operation at the
maximum output power allowed for compliant operation under the FCC part 15 regulations. In
both the headend and the subscriber units the input power level to the ARCell transceivers
determines the output power. There is no gain adjustment available to the user in the
transceiver.
5.5.2 Downstream Power
The AR3155 Hub Transceiver is factory calibrated to provide RF power output of +36 dBm
maximum EIRP (FCC Rules Section 15.247) when the input power applied to the upconverter IF
input connector is +35 dBmV. This is the level required for FCC compliance.
5.5.3 Downstream Power Adjustment Procedure
1. Disconnect the downstream IF cable at the input to the Hub Transceiver and connect the
cable to the input of a suitably calibrated RF power meter such as a CATV level meter.
Ensure that the IF signal power does not exceed +35 dBmV.
2. Alternatively, a spectrum analyzer can be utilized if it has a 75 ohm input impedance and
can display power in dBmV.
a. Adjustment must be made for the resolution bandwidth (RBW) of the analyzer
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.
For example, in the case of the AR3155, if the RBW is set for 1 MHz, the actual
power level will be 10log(5.25) or 7.2 dB higher than the average power
displayed on the analyzer.
3. Set the IF output level of the W-CMTS or external upconverter, or by inserting fixed
attenuators as needed.
4. If the AR3155 Hub Transceiver is inaccessible for power measurement, the level at the
W-CMTS or external upconverter can be measured and adjustment made for
transmission line loss
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. For example, if the transmission line loss is known to be 10 dB
including any taps or splitters, the W-CMTS or external upconverter output can be set for
+45 dBmV which will provide the required +35 dBmV power level at the input of the Hub
Transceiver.
In any case, it is the responsibility of the system operator to ensure that the proper
input level is applied to the AR3155 Hub Transceiver.
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The formula is (actual power) = (displayed power) + 10log[(signal bandwidth) ÷ (RBW)].
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See cable manufacturer’s specifications. Standard RG-6 coaxial cable has a loss of 4.6 dB /100 ft. at
500 MHz.
June 2003 Page 5-14