User's Manual

ADCP-75-187 • Preliminary Issue 1B • November 2005 • Section 3: OPERATION

Page 3-6

24. If a separate laptop computer loaded with the EMS software was used to initially

configure the system, disconnect the laptop computer from the SERVICE connector.

25. Reconnect the external alarm system or notify the alarm system provider that the turn-up

process has been completed.

2.1 Reference Procedure: Determine Forward Path Input Signal Level

The level of the composite RF input signals received at the host unit FORWARD RF IN port(s)

will vary depending on the EBTS, the cable loss, the number of channels present, and the

required forward path composite power. If maximum composite RF output is required at the

RU, the level of the composite RF input signal received at the HU must fall within a range of –9

to –40 dBm. If the signal level is not within this range, it must be adjusted using an external

attenuator. Note: The 800/900 MHz SMR host unit has two FORWARD RF IN ports. Use the

851–869 FORWARD RF IN port to complete this procedure. Then repeat this procedure for the

935–940 FORWARD RF IN port.

When connecting a single HU to a single EBTS, use the following procedure to measure and

adjust the input RF signal level at the HU:

1. Connect a spectrum analyzer or power meter to the forward path output port at the EBTS.

The required signal levels and test points for 800/900 MHz SMR systems are shown in

Figure 3-3. The required signal levels and test points for 800 MHz and 1900 MHz

systems are shown in Figure 3-4. Note that 800/900 MHz SMR Host Units have two

forward path ports.

2. If using a spectrum analyzer, proceed to step 3. If using a power meter, measure the

composite signal power from the EBTS and then proceed to step 5.

3. Measure the RF level of a single carrier, such as the control channel, in dBm. Make sure

the resolution bandwidth of the spectrum analyzer is 30 kHz. Maximum power in any

channel should not exceed 5W (+37 dB).

4. Calculate the total composite signal power from the EBTS using the following formula:

tot

= P

+ 10Log N where,

tot

is the total composite power in dBm

is the power per carrier in dBm as measured in step 3, and

N is the total number of channels.

Note: When two or more HU’s are connected together through the CAN interface, only

one EMS computer is required to manage the networked Digivance systems. The EMS

computer may be connected to the SERVICE port on any one of the HUs in the network.

Note: The optimum level for an 800/900 MHz SMR composite input signal is –20 dBm

Note: Check the input rating of the test equipment and the output rating of the EBTS. To

avoid burning out the spectrum analyzer or power meter, it may be necessary to insert a

30 dB 100W (or similar) attenuator between the EBTS and test equipment.