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

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

Thanks Harvind, I was just speaking with my friend from university lab
and he can maybe help me to measure clock with frequency counter
which will help me to set the appropriate offset.

-- Tomas

> Tomas,
>
> If you're convinced that there's still a residual clock offset, then try
> messing around with the FREQ_OFFSET parameter in Transceiver.cpp.  Try
> moving it around a 500Hz at a time.
>
> --- 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.
>>>
>>>   
>>>       
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>
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