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Tests to verify the faulty RF cables The following procedures can be used to verify the RF cables:-

1) The TRX Test can be run using the BTS manager.

2) The faulty cable isolation test sequence.

NOTE: The TRX Test can be used to find any badly damaged RF cables but may not identify all the damaged cables that can lead to the TRX/BCF restart issue. It may also be necessary to perform the faulty cable isolation test.

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TRX Test Method

The TRX test can be run for each individual TRX installed at the site.

Before this:-

Disable BB or AHOP from the sector under test.

The power for the sector should be PMAX=0 (set at BSC).

A faulty cable may give failed TRX test results with one of the following reasons:-

> Low Power in Abis1- Air3 Loop

> RF cables not connected.

* A snapshot of follows.

* A document is attached describing the Tests from BSC for different configurations.

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Snap Shot of TRX Test

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Faulty Cable Isolation test

Faulty RF cables can be isolated in the following manner:

1) Connect the BTS Manager to the BTS (ESMA LMP)

2) Disable BB or Antenna Hopping from the BSC for all sectors of the BCF/Site as it

would not permit TRX blocking/unblocking in a BB/AHOP sector.

3) Verify that all the sectors are radiating at maximum power which can be verified from the

BSC using the command: ZEUO:BTS=;

4) Block all TRX of the Site locally from the BTS Manager.

5) For each sector at a time, unblock one TRX at a time (this would enable the BCCH to

reconfigure to each TRX at a time. This will enable sufficient power available on the cable

to be able to test each cable successfully.

6) On the BTS Control drop down menu of the BTS Manager, select the Power Control

Option and Change the Control from User to BTS (If it is not already there).

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Faulty Cable Isolation Continued

7) Bring the door of the cabinet or a sufficient sized metal plate in front of the radiating TRX Tx port. Try this a number of times varying the distance from the BTS and speed of movement ie slowly and fast.

8) When this activity is performed on a TRX with a faulty RF cable, it will be observed

on the power control box that the display of any one or more of the six power ports of

the Power Distribution Unit (PDU) turn from Green to a Question Mark in Red denoting

an Unknown State.

9) Note that before removing any TX cable, block the TRX locally first or a VSWR major

alarm may block the TRX which would require a sector reset from the BSC

10)The TX cable should be immediately removed from the TRX and replaced. This new cable should again be verified in the same way before any other TRX is unblocked.

11) Repeat the activity on each TRX one at a time. Unblocking it to do the testing and

Blocking it again after verifying the integrity of the Tx cable.

12) For each TRX, after verifying that the Tx cable is OK, swap it with its Rx cable to

also verify its integrity before unblocking any other TRX.

13) In some cases a BCF Reset may also be observed on the site.

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Description of the Cable

The cable is an RG 400 cable with QMA Male type connectors at both ends. Cable codes:

994931b RA QMA RF CABLE ASSEMBLY 172 MM

994933b RA QMA RF CABLE ASSEMBLY 275 MM

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The RF cables might look and feel very flexible and robust but should be handled with extreme care as a broken or damaged cable may cause many quality and reduced output power issues.

The tests described earlier should be performed to isolate any damaged RF cables on sites displaying any unintentional reset or RF quality issues.

The damaged cables should be removed and then disposed of immediately.

Summary