Nortel Networks DCT1900 - Manual (Page 227)

Technical Product Manual - DCT1900
Installation Instructions, Base Station – KRC 101 1371
Install-DCT1900/R8/mw 16-5
© 2000-2005
Correct implementation of the automatic delay measurement requires that the base station be
connected to the Radio Exchange and powered when adding the base station using the CSMW
software. In previous installations the software requested the measured delay value. With the
above revisions, entering the default value of 0.1 microseconds will initiate the Auto Delay
Measurement. In the “Add Base Station” command process, the SLU/ CLU-S will talk to the base
station and determine the time delay. This determined value will never be displayed in any of the
system screens. The delay table will always reflect the value of .1 if it was chosen. If you enter
a TDR measured value other than 0.1, e.g.: 1.5, then this value will be used and displayed by the
system.
In automatic mode the system determines the cable delay measurement every time the base
station is powered, reset or when it is added.
Procedure
1. Install and terminate the Base Station cable with a RJ-45 connector.
2. Mount and connect the Base Station.
3. At the base station window, refresh and verify that the status is NEW for every Base Station to
be added. If it is not, then trouble shoot the lines and hardware. In addition, a red LED on
each of the CLU-S/SLU boards indicates a newly connected Base Station.
4. Add the Base Stations by selecting the CLU address, the base station port and the cable delay
value which can be set to automatic or manual.
5. After all of the Base Stations have been added, each new base station will have a "Pending”
status if the RE was initialized as a UTAM system. If the RE was initialized as a non-UTAM
system, the status will change to AVAILABLE.
6. Activate the Base Stations with the correct UTAM password if the RE was initialized as a
UTAM system.
7. Refresh the window to see the status of the new Base Stations as "Available."
8. Back up the system data.
9. Set two or more portables in engineering mode to perform a "walk around" test. Check for
proper system operation, voice quality, handovers, and coverage.
Note:
The new DCT1900 Auto Delay Measurement system does not eliminate the need to use a TDR.
The quality of the cable, and the possibility of wiring errors could negate the automatic
measurement capability.
The second method, using a TDR, is explained in the following paragraph.
Base Station delays are measured at the RE with a TDR connected first to cable data pair SC0
and then to cable SC1 with the cable open ended at the far end and then shorted at the far end.
While it is not necessary to determine the delay in the EPP pairs, if they are used, it is
recommended that these pairs be checked with the TDR to ensure that they are going to where
they are supposed to be and are not open/shorted anywhere.
1.
Make sure that the Base Station cable is unplugged from the Base Station.
2. Disconnect the relevant connector from the relevant CLU or SLU.
3. Connect the TDR to cable pair SC0 or SC1 or EPP (refer to Chapter 25 on how to use the
TDR).
4. Measure the cable delay. The measured delay is the time between sending a pulse down the
line and receiving the echo. The resulting value must have an accuracy of 200 ns
(corresponding with 18–27 ft.).