Re: [Openbts-discuss] How to set RxGain in GPRS branch?

[Alexander C. <ale...@gm...>]

GPRS has it's own power control, independent of the CS (circuit
switched aka voice/sms) service. Ivan could comment more, but IIRC
power control is not implemented in the current code yet. So you
mobile could easily transmit with too much or too small power.

Patches to implement power control control are welcome. :)

On Tue, Jun 25, 2013 at 1:30 AM, Gullik Webjörn
<gul...@co...> wrote:
> Hmm, can you see the MS tx power in chans command?
>
> I had to experiment quite some before i got the phones to adjust down,
> but at
> that time I was more ignorant :-)
>
> What happens if you move the phones away? When I was trying to
> understand my problems
> I would call the "echo service" from different places. For your case
> that would be a "packet"
> connection? Where in the stack does GPRS interface itself?
>
> Gullik
> On 06/24/2013 05:10 PM, oxccoxcc oxccoxcc wrote:
>> I tried to set GSM.MS.Power.Max to 1 and GSM.MS.Power.Min to 1. But RSSI value is still high (about -25 for WBX, -15 for SBX).
>> Tried to change WBX daughterboard to SBX. Receive burst quality is also bad and not all of them can be resolved. It looks like a wavy process.
>> At some time bursts have an ideal quality. At another time they are broken. Periodically they are broken partially, for eaxample: (10100...11100110010100--------------...--)
>> I also tried to change ARFCN, but it didn`t help. Before i checked this arfcn with uhd_fft.
>> One thing, that looks some strange is a timing value=2.00391. This value is constantly at all sessions for PDTCH channel and 2 symbols offset is looks too high for phone, that places near USRP.
>>
>> 24.06.2013, 17:00, "Gullik Webjörn" <gul...@co...>:
>>> Maybe a moot point, but I think it is not a B100 problem if
>>> exactness is the issue, but rather a WBX issue.
>>>
>>> The same thing should happen on another USRP equipped with WBX,
>>> if RxGain is left at +47 dB.
>>>
>>> Regards,
>>>
>>> Gullik
>>>
>>> On 06/24/2013 12:59 PM, oxccoxcc oxccoxcc wrote:
>>>
>>>>   According to USRP B100 RxGain problem, i set GSM.Radio.RxGain to 7dB. After that not RACH bursts have an RSSI value about -80 - -87 and normal quality.
>>>>   But when i starting GPRS and connect to web page, receive bursts RSSI grow to -10 - -15. And, because of that, receive bursts have a bad quality and most of them can`t be resolved.
>>>>
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-- 
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru