ADC DIS080AB Users Manual

5 SYSTEM OPERATION

This section provides guidelines for turning-up the Digivance ICS, verifying that all units are
operating properly, testing to ensure that all performance requirements are satisfied, and
correcting any installation problems. This process assumes that the various units that comprise
the Digivance ICS have been installed in accordance with the system design plan and the BTS
interface unit (HPCP or RIU) has been installed and tested. The procedures for installing and
testing the HPCP or RIU are provided in the user manual that is shipped with the unit.

5.1 Tools and Materials

The following tools and materials are required in order to complete the procedures in this
section:

• Portable spectrum analyzer

• Portable test transmitter

• Cell phone

• Pencil or pen

• Writing pad

ADCP-75-130 • Issue 3C • August 2006

5.2 Turn-Up System and Verify Operation

The process of turning-up the system and verifying operation involves powering up the
various system components and then verifying that the LED indicators show normal
operation. Refer to Tables 8, 9, and 10 as needed for a complete description of the unit LED
indicators. Use the following procedure to power-up the system. If any unit does not respond
as described, refer to Subsection 5.4 for the correction procedures.

1. Temporarily disconnect the alarm system or notify alarm system provider that testing is
in progress.

2. Verify that each AC powered unit is connected to the appropriate outlet.

3. Place the ON/OFF switch on the DHU in the ON position (press I).

4. Verify that the UNIT LED and the OVERDRIVE LED on the DHU turn yellow (for
approximately 6 seconds) and then green.

5. If DHU will be connected to an ancillary interface device, adjust the level of the RF
input and output signals at the DHU and complete all remaining coaxial cable
connections as described in Section 5.3.

6. Place the PORT 1 ON/OFF switch on the DHU in the ON position (press I).

7. If a DEU is connected to port 1, proceed to step 8. If a DRU is connected to port 1, skip
steps 8 and 9 and proceed to step 10.

8. Place the ON/OFF switch on the DEU in the ON position (press I).

9. Verify that the UNIT LED on the DEU turns yellow (for approximately 6 seconds) and
then green.

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10. Verify that the PORT 1 OK/NOK LED on the DHU turns yellow (for approximately 6
seconds) and then green.

11. If a DEU is connected to PORT 1, proceed to step 12. If a DRU is connected to PORT 1,
skip steps 12 through 14 and proceed to step 15.

12. Verify that the HOST PORT LED on the DEU turns green.

13. Place the PORT 1 ON/OFF switch on the DEU in the ON position (press I).

14. Verify that the PORT 1 OK/NOK LED on the DEU turns yellow (for approximately six
seconds) and then green.

15. Verify that the STATUS LED on the DRU connected to PORT 1 turns yellow (for
approximately six seconds) and then green.

16. Repeat the procedure covered in steps 6 through 15 for each of the remaining DHU
optical ports (ports 2 through 6) that is connected to a DEU or a DRU.

17. Reconnect the alarm system and notify alarm system provider that system is operational.

Table 8. Digital Host Unit LED Indicators

INDICATOR COLOR DESCRIPTION

UNIT
LED

PORT 1–6
OK/NOK
LEDs

OVERDRIVE
LED

Note: Detection of any fault will generate an alarm. A high temperature fault will generate a minor alarm
(yellow LED). All other types of faults will generate a major alarm (red LED).

Green

Yellow

Red

Off

Green

Yellow

Red

(steady)

Red

(blinking)

Off

Green

Red

Indicates when the DHU is normal or faulty.

DHU in normal state, no faults detected.

DHU high temperature fault detected. (see Note)

DHU fault detected (see Note).

AC power off to DHU or DHU internal fault.

Indicates if any connected DEU or DRU is normal or faulty or if the
optical inputs from any connected DEU or DRU are normal or lost.

All connected units in normal state, no faults detected.

High temperature fault detected in connected DEU. (see Note)

Fault detected in a connected DEU or DRU. (see Note)

No reverse path optical signal detected from a connected DEU or DRU or
excessive reverse path errors detected from a connected DEU or DRU.
(see Note)

Port disabled (via front panel switch) or DHU internal fault.

Indicates when the forward path RF input is below or above the
overdrive threshold.

RF input signal level at DHU below overdrive threshold.

RF input signal level at DHU above overdrive threshold.

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Table 9. Digital Expansion Unit LED Indicators

INDICATOR COLOR DESCRIPTION

ADCP-75-130 • Issue 3C • August 2006

UNIT
LED

HOST PORT
LED

PORT 1–6
OK/NOK
LEDs

Green

Yellow

Red

Off

Green

Red

(blinking)

Off

Green

Yellow

Red

(steady)

Red

(blinking)

Indicates when the DEU is normal or faulty.

DEU in normal state, no faults detected.

DEU high temperature fault detected. (see Note)

DEU internal fault detected. (see Note)

AC power off to DEU or DEU internal fault.

Indicates when the optical inputs from the DHU or supporting
DEU are normal or lost.

DHU or supporting DEU in normal state, no faults detected.

No forward path optical signal detected from DHU or supporting DEU or
excessive forward path errors detected from DHU or supporting DEU.
(see Note).

DEU internal fault.

Indicates if any connected DEU or DRU is normal or faulty or if the
optical inputs from any connected DEU or DRU are normal or lost.

DRU or remote DEU in normal state, no faults detected.

High temperature fault detected in connected DEU. (see Note)

Fault detected in a connected DEU or DRU. (see Note)

No reverse path optical signal detected from a connected DEU or DRU or
excessive reverse path errors detected from a connected DEU or DRU.

Port disabled (via front panel switch) or DEU internal fault.

Off

Note: Detection of any fault will generate an alarm. A high temperature fault will generate a minor alarm
(yellow LED). All other types of faults will generate a major alarm (red LED).

Table 10. Digital Remote Unit LED Indicator

INDICATOR COLOR DESCRIPTION

STATUS
LED

Green

Red

(steady)

Red

(blinking)

Off

Indicates if the DRU is normal or faulty or if the forward path optical
inputs to the DRU are normal or lost.

DRU in normal state, no faults detected.

DRU internal fault detected. (See Note)

No forward path optical signal from the DHU or DEU detected.

DC power off to DRU or DRU internal fault.

Note: Detection of any fault will generate an alarm. A high temperature fault will generate
a minor alarm (yellow LED). All other types of faults will generate a major alarm (red LED).

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ADCP-75-130 • Issue 3C • August 2006

5.3 RF Input and Output Signal Level Adjustments

The DHU may be connected to either a donor antenna or a base transceiver station through an
ancillary interface device. The following sections provide general guidelines for using the
interface device to adjust the forward and reverse path signals to the correct level.

5.3.1 Forward Path RF Signal Level Adjustment

Use the following procedure to adjust the level of the forward path composite RF signal input
to the DHU so that the maximum RF output signal level is provided at the DRU:

1. Complete all remaining forward path coaxial cable connections between the BTS and the
local interface device or between the antenna and the remote interface device as
specified in the instructions provided with the equipment.

2. Connect a spectrum analyzer or power meter to the forward path output port on the
interface device.

Note: Check the input rating of the test equipment and the output rating of the interface

device. 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 interface device and test
equipment.

3. Adjust the interface device to provide the maximum RF signal level at the output port.

4. If using a spectrum analyzer, proceed to step 5. If using a power meter, measure the
composite signal power from the interface device and then proceed to step 7.

5. 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.

6. Calculate the total composite signal power from the interface device using the following
formula:

P

= Pc + 10Log N – (see Note)

tot

Where,

P

P

is the total composite power in dBm

tot

is the power per carrier in dBm as measured in step 4

c

N is the total number of channels.

7. Adjust the interface device to provide a composite RF signal level of approximately –20
dBm at the interface device RF output port.

8. Disconnect the test equipment from the interface device

9. Connect the forward path cable (attached to the RF IN connector on the DHU) to the
interface device RF output port.

10. Use the interface device to slowly increase the level of the forward path RF signal
supplied to the DHU. Make all adjustments to the signal level in 1 dB increments.

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ADCP-75-130 • Issue 3C • August 2006

Caution: Do not supply the DHU with an RF input signal that is 0 dBm or greater or the

system could be damaged.

11. Continue to increase the forward path RF signal level until the DHU overdrive LED just

begins to turn red.

12. Reduce the level of the RF input signal by 1 dB and then verify that the DHU Overdrive
LED stays green.

5.3.2 Reverse Path RF Signal Level Adjustment

The level of the reverse path composite RF signal output from the interface must be adjusted
so that the correct RF signal level is input to the BTS or the antenna. When the level of the
reverse path signal at the DRU antenna port is at a composite maximum of –40 dBm, the level
of the RF output signal from the DHU will be –30 dBm. This equals a system gain of 10 dB.
Use the following procedure to adjust the reverse path RF signal level:

1. Complete all remaining reverse path coaxial cable connections .

2. Determine the maximum acceptable DRU path loss per the system design specifications.

3. Determine the total cable loss that will be imposed by the reverse path coaxial cables and
any other devices (splitters, connectors, etc) that will impose a lose on the signal.

4. Determine the total gain that will be provided by the DRU antenna and by the donor
antenna (if present).

5. Use the following formula to calculate the total gain or loss that must be added by the
interface device to provide unity gain:

Reverse Path Gain/Loss Required = [∑ System Insertion Loss + Designed Path Loss*] –

[System Gain (10 dB) + ∑ Antenna Gain]

*Designed path loss is defined as the loss between a BTS antenna and a donor site antenna.

6. Adjust the interface device to provide the amount of gain or loss required per the
calculation in step 5.

5.4 Test System Performance

Testing the performance of the system involves completing various RF tests and telephone
service tests that verify if the system is functioning properly. Use the following procedure to
test the system performance:

1. Verify that the forward path (downlink) input signal level at the DHU is optimized. The peak

COMPOSITE forward path input signal level at the DHU should be set at –20 dBm.

Note: In a CDMA system, the power level is dependent on the traffic. For optimum

operation in a CDMA system, the input signal level should be set below the level of the
pilot signal.

2. Verify that the reverse path (uplink) signal level at the local BTS or donor antenna is
optimized. Note that the reverse path output signal level required is dependent on service
provider signal to noise requirements, ICS system noise floor, the service provider
equipment, and the system configuration.

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3. Check and record the Received Signal Strength Indication (RSSI) and any spurious
emission levels at and between all DRU antennas. Analyze all DRU’s and the DHU
interface using a spectrum analyzer.

4. Plot the RSSI levels on a floor plan of the building and check against the pre-installation
RSSI levels to determine the overall and average RSSI improvement attributed to the
Digivance ICS. Check the entire Digivance coverage area.

5. Verify call processing and voice quality within the coverage areas. Initiate and receive
multiple long and short duration calls. Document the performance and address any issues
as calls are processed within the entire coverage area. Assuming a properly functioning
server RF link and BTS and a properly designed and optimized ICS system, there should
be no clicks, mutes, clipping, or crackles within the coverage area. In a wireless office
application, hand off will not occur.

6. If the DHU interfaces with a local BTS (microcell), verify the handoff function by
placing a call and confirming handoffs between the Digivance/microcell coverage area
and the outdoor macrocell coverage area (macro system) and vice versa. The handoff
should take place without any noticeable call quality or performance issues.

7. If the DHU interfaces with a remote BTS through a donor antenna, verify call quality by
placing a call and then walking between the Digivance coverage area and an area
receiving good coverage directly from the cell site base station. There should be no
noticeable difference in call quality.

8. Following service provider guidelines, test the 411 and 911 links to verify the routing of
emergency and special services calls on local BTS configurations.

9. Verify that the alarm reporting system functions properly by turning the DHU off. This
should generate a major and minor alarm and operate both the major and minor alarm
contacts. Check for alarm confirmation from the service provider’s local switch and
Network Operations Center (NOC). Note that this tests only the external alarm system
and does not verify operation of the Digivance alarm reporting system.

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6 SYSTEM MAINTENANCE PROCEDURES

This section explains the alarm reporting system, provides a method for isolating and
troubleshooting faults, and provides procedures for replacing the modular transceivers and the
DHU or DEU cooling fans.

The Digivance ICS requires no regular maintenance to insure continuous and satisfactory
operation. Maintenance, as it applies to the Digivance ICS, primarily involves diagnosing and
correcting service problems as they occur. When an alarm is reported, it will be necessary to
follow a systematic troubleshooting procedure to locate the problem. Once the source of the
problem is isolated, the appropriate corrective action can be taken to restore service. The only
unit components that can be replaced are the cooling fans that mount in the DHU and DEU
and the modular optical transceivers. The failure of any other component within a unit will
require replacement of that unit.

6.1 Tools and Materials

The following tools and materials are required in order to complete the procedures in this
section:

ADCP-75-130 • Issue 3C • August 2006

• ESD wrist strap

• IR filtering safety glasses

• Optical loopback device (such as Stratos Lightwave LC5 series) and LC duplex adapter

• Optical power meter

• Magnification device for inspecting LC connectors

• Laser light source

• Multimeter

• Cell phone

• RJ-45 circuit access tool (such as the Harris 8-wire Banjo Adapter)

• Medium and small size flat-bladed screwdrivers

• TORX screwdriver (T10)

6.2 Fault Detection and Alarm Reporting

Detection of a fault by the Digivance ICS will generate an external alarm response. LED
indicators are provided on the front panel of the various units to indicate when a fault is
detected. In addition to LED indicators, the DHU also provides normally open (NO) and
normally closed (NC) dry alarm contacts for reporting minor and major alarms to an
external alarm system. A minor alarm is defined as a high temperature condition. A major
alarm is defined as any fault condition except high temperature.

When the DHU alarm contacts are connected to an external alarm system, detection of a fault
will generate an alarm at the Network Operations Center (NOC). However, various types of
faults may not generate an alarm response. In this case, the first indication of a problem will
probably be from cell phone users reporting a loss of service or poor service. Whenever a
problem is reported, whether by a external alarm system or by a call from a user, refer to
Subsection 6.3 to isolate and correct the fault.

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6.3 Fault Isolation and Troubleshooting

Fault isolation and troubleshooting guidelines are provided in Tables 11, 12, 13, and 14. When an
alarm is reported, determine the type of alarm generated (minor or major) and then check the LED
indicators on the DHU and note any that are red, yellow, or off. If any of the Port 1–6 OK/NOK LED
indicators on the DHU are red or yellow, also check the LED indicators on the connected DEU’s
and/or DRU’s and note if any are red or yellow. Start the troubleshooting process at the DHU and then
work toward the unit where the alarm originated. The troubleshooting tables are organized according
to unit type. Locate the problem in the appropriate table, check out the suggested possible causes, and
take corrective action as required.

Figure 24 shows two basic ICS system configurations. The troubleshooting tables list possible causes
for various problems. If the cause of a particular problem is specific to either of the two system
configurations shown in Figure 24, the type of system configuration (1 or 2) will be referenced in the
table.

DIGITAL HOST UNIT

REV

DRU

(1)

FWD

REV

DIGITAL EXPANSION UNITDIGITAL HOST UNIT

(2)

FWD

Figure 24. ICS System Basic Configurations

Table 11. DHU Fault Isolation and Troubleshooting Guidelines

Alarm Type LED LED COLOR

Minor UNIT Yellow

Problem : The DHU is overheating.

POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS

1. Air intake or exhaust openings to DHU

chassis blocked.

2. Ambient temperature > 50º C/122º F.

3. Faulty fan.

Alarm Type LED LED COLOR

Major UNIT Red

Problem : The DHU detects an internal circuitry fault.

POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS

1. Faulty DHU. 1. Replace DHU.

1. Remove cause of air-flow blockage.

2. Reduce ambient temperature.

3. Replace fan (see Subsection 6.5).

REV

FWD

DRU

17962-A

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(Continued)

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Table 11. DHU Fault Isolation and Troubleshooting Guidelines (Continued)

Alarm Type LED LED COLOR

Major OVERDRIVE Red

Problem: Forward path RF input level too high.

POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS

1. Incorrect attenuation in forward path RF

1. Adjust attenuation at RIU or LIU.

coaxial link.

Alarm Type LED LED COLOR

Minor OK/NOK Yellow

Problem: The DHU is receiving a minor alarm signal from the DEU.

POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS

1. The connected DEU is overheating (2). 1. Check DEU UNIT indicator and then refer to the
appropriate troubleshooting section for procedures.

Alarm Type LED LED COLOR

Major OK/NOK Blinking Red

Problem: The DHU is not receiving an optical signal from the DRU or DEU.

POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS

1. Forward and reverse path optical fibers

reversed between DHU and DRU (1); or
between DHU and DEU (2).

2. Faulty reverse path optical fiber between DHU

and DRU (1).

3. Faulty optical receive port at DHU or faulty

optical transmit port at DRU (1).

4. Faulty forward or reverse path optical fiber

between DHU and DEU (2).

1. Check fiber connections for correct polarity and
reverse connectors at either unit if mismatched.

2. Clean optical connector and then test optical fiber.
Repair or replace if faulty (see Subsection 6.4.2).

3. Make sure transceiver is fully plugged in and then
test optical port. Replace optical transceiver if
port is faulty (see Subsection 6.4.1).

4. Clean optical connectors and then test optical
fibers. Repair or replace if faulty (see
Subsection 6.4.2).

Alarm Type LED LED COLOR

Major OK/NOK Red

Problem: The DHU is receiving a major alarm signal from the DRU.

POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS

1. Faulty forward path optical fiber between

DHU and DRU (1).

2. Faulty optical transmit port at DHU or faulty

optical receive port at DRU (1).

3. The DRU is faulty (1 and 2).

4. Faulty forward or reverse path optical fiber

between the DEU and DRU (2).

1. Clean optical connector and then test optical fiber.
Repair or replace if faulty (see Subsection 6.4.2).

2. Make sure transceiver is fully plugged in and then
test optical port. Replace optical transceiver if
port is faulty (see Subsection 6.4.1).

3. Check DEU UNIT indicator or DRU STATUS
indicator and then refer to appropriate trouble­ shooting section for procedures.

4. Check the status of the OK/NOK LED on the
DEU and then Refer to Table 12.

© 2006, ADC Telecommunications, Inc.

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