Re: [Openbts-discuss] camping with 52MHz clock

[Tomas K. <de...@vo...>]

Harvind,

I'm sorry for my late response, I was suddenly out of civilization. I
tried your patch, but unfortunatelly it didn't help.
With the patch I was unable to scan OpenBTS by any handset; I performed
scan of patched OpenBTS several times -> scan of unpatched -> scan of
patched ... etc.
Unpatched OpenBTS (2.5) was scanned successfuly everytime at least by
Siemens MT50.

Anyway with openbts-2.5 (without the patch), if I switched off/on MT50
and scanned networks, I found all 3 real networks in Czech + OpenBTS.
With Nokia 2600 I found OpenBTS + one real network. Measurement in
university lab was not available yet, but it should be hopefully next week.

Tomas


> Tomas,
>
> I think I found a couple of bugs in the 2.5 Transceiver.
>
> Please try these files out and see if they help.
>
> --- Harvind
>
> On Tue, 2009-12-01 at 23:08 +0100, Tomas Kopsa wrote:
>   
>> I have been testing with new external 52MHz clock but I'm stucked
>> exactly with the issue described by Alexander below. I have 3x Siemens
>> MT50 and one CF62 which connect mostly
>> on the first try when scanning networks. It scan sometimes OpenBTS +
>> real networks and sometimes either OpenBTS or real networks. Newer
>> phones cannot see both in every case I did
>> and I have to scan many times to reach OpenBTS. I feel there is still
>> big offset. Is it supposed to happen with the external 52MHz clock or
>> did I a mistake somewhere ?
>>
>> Is it possible to reduce the offset with e.g. kal-0.2 ? (My
>> configuration was gnuradio 3.1.3 & openbts-2.5)
>>
>> Thanks,
>> Tomas
>>
>>     
>>> This may be due to clock offset / unstable clock issue.
>>> When I set clock to ~400-500Hz offset, phones can't connect to
>>> OpenBTS reliably. Old Siemens and Nokia phones do this pretty
>>> easily, but newer ones do not and you have to try many times.
>>>
>>>   
>>>       
>> ------------------------------------------------------------------------------
>> Join us December 9, 2009 for the Red Hat Virtual Experience,
>> a free event focused on virtualization and cloud computing. 
>> Attend in-depth sessions from your desk. Your couch. Anywhere.
>> http://p.sf.net/sfu/redhat-sfdev2dev
>> _______________________________________________
>> Openbts-discuss mailing list
>> Ope...@li...
>> https://lists.sourceforge.net/lists/listinfo/openbts-discuss
>>     
>> ------------------------------------------------------------------------
>>
>> ------------------------------------------------------------------------------
>> Join us December 9, 2009 for the Red Hat Virtual Experience,
>> a free event focused on virtualization and cloud computing. 
>> Attend in-depth sessions from your desk. Your couch. Anywhere.
>> http://p.sf.net/sfu/redhat-sfdev2dev
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> Openbts-discuss mailing list
>> Ope...@li...
>> https://lists.sourceforge.net/lists/listinfo/openbts-discuss