Questions regarding maintaining synchronization of a mobile station

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Piotr Krysik ptrkrysik at
Fri Sep 21 08:07:20 UTC 2018

Hi all,

Gr-gsm's receiver currently relies on having SCH channel to keep
synchronization. I want to remove that requirement so it'll be more
usable in an SDR based burst transceiver for OsmocomBB.

To do this it would be great to know how normal mobile phones maintain
synchronization, something I don't know currently. Especially:
1. How often mobile station (MS) checks if the synchronization is kept?
2. What is usually used to check if synchronization is kept, especially
when a MS is on a traffic channel?
3. How MS regains synchronization? Does it always do full FCCH+SCH scan?

Thanks in advance,
Piotr Krysik

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