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

[Gullik W. <gul...@co...>]

Hah, I'm getting better in "guessing", in fact a lot of this
is documented in the pcu / gprs threads....

It seems to me that the power algorithm maybe should be
located somewhere where ALL modes of communication
converge, i.e. before multiplexer / demultiplexing.

Gullik

On 06/25/2013 08:42 AM, Alexander Chemeris wrote:
> 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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