User's Manual

CSM System Time – GPS & LFR/HSO Verification68P09258A31–A

Oct 2003

1X SCt 4812T BTS Optimization/ATP

3-51

Table 3-20: GPS Initialization/Verification

Step Action

7 Verify the following GPS information (shown above in underlined text):

– At least 4 satellites are tracked, and 4 satellites are visible.

– GPS Receiver Control Task State is “tracking satellites”. Do not continue until this occurs!

– Dilution of Precision indication is not more that 30.

Record the current position base site latitude, longitude, height and height reference (height reference

to Mean Sea Level (MSL) or GPS height (GPS). (GPS = 0 MSL = 1).

If steps 1 through 7 pass, the GPS is good.

NOTE

If any of the above mentioned areas fail, verify that:

– If Initial position accuracy is “estimated”

(typical), at least 4 satellites must be tracked and

visible (1 satellite must be tracked and visible if actual lat, log, and height data for this site has

been entered into CDF file).

– If Initial position accuracy is “surveyed”,

position data currently in the CDF file is assumed to be

accurate. GPS will not automatically survey and update its position.

– The GPS antenna is not obstructed or misaligned.

– GPS antenna connector center conductor measures approximately +5 Vdc with respect to the

shield.

– There is no more than 4.5 dB of loss between the GPS antenna OSX connector and the BTS frame

GPS input.

– Any lightning protection installed between GPS antenna and BTS frame is installed correctly.

9 Enter the following commands at the CSM> prompt to verify that the CSM is warmed up and that GPS

acquisition has taken place.

debug dpllp

Observe the following typical response if the CSM is not warmed up (15 minutes from application of

power) (If warmed–up proceed to step 10)

CSM>DPLL Task Wait. 884 seconds left.

DPLL Task Wait. 882 seconds left.

DPLL Task Wait. 880 seconds left. ...........etc.

NOTE

The warm command can be issued at the MMI port used to force the CSM into warm–up, but the

reference oscillator will be unstable.

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