[Kashif Riaz]

hi there, i am Kashif NSS Engineer from Pakistan working on Samsung CDMA MSC. I am facing Cross Talk problem on OnNet calls. Your kind opinions are awaited to help me out to find the proper reason of it.

[Rajiv Gujral]

Hi Riaz

From the RF point of view, better u check your MAIO plan. There must be no repetitions of MAIO with in the same sector.

Regards

Rajiv

[Kashif]

Thanks, but does it have to do anything related to MSC and BSC E1 inertaface.

[Ake]

It is possible that somewhere on the connection between BSC and MSC has got mixed up, especially on the wires between the digital path. Try to narrow it down to the specific group by tracing the CIC number once problem appears, then check the wire of that digital path from point to point. This issue is usually found in USA since there are a lot of wires of balance impedance installed in the switch.

[Kashif]

Thx for your response dera…so i can get the idea that there is some impedance mismanthcing in the wires for connectivity…

[Ake]

Hi Kashif,

Not really impedance mismatch. In balance impedance wires, there are 4 cables (2 for TX, 2 for RX) / PCM, there is posibility that TX and RX could be mixed up between the PCMs during installation. It will then cause a cross talk issue.

Hope it helps.

[Kashif]

It is strange happening here, as these cables have been installed a time ago n they were working fine but noe Cross Talk has started. So can the same reason be take for it as well.

[Ake]

Were those PCMs where are associated with those cables tested (PCM by PCM) before commercial launch? We also had the same issue in US that we randomly tested the PCMs but unfortunately the cross talk happened on the ones that we did not test…things happen.! If you are not sure that all PCMs/Cables were tested before, I suggest to recheck the problematic PCM by checking wires/connections point by point again.

[Kashif]

yea dear u r right as all the PCMs were not tested and only random PCMs were tested so i’ll do check them point to point..Thx for the help

[Ake]

Let me know if you find something.

[Sameer India]

Hi Kashif
I think cross talk can be caz of CIC mismatching also.If in a perticular E1 cics are not matching at both end then this prob will occure.to rectify this you need to remove all working e1s except one and try test calls if OK move further.

Sam

[Author]

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