openbts-p2.8-gprs-exp and pcu issues

Vladimir Rolbin vrolbin at gmail.com
Thu Nov 1 23:11:20 UTC 2012


Ok, thanks for patch. I will be able to ckeck ot only on Sunday ..

Regards,
Vladimir


On Thu, Nov 1, 2012 at 10:55 PM, Ivan Kluchnikov <
Ivan.Kluchnikov at fairwaves.ru> wrote:

> Hi, Vladimir!
>
> Thank you for your fixes, I will check and apply them tomorrow!
> In attachment you can find patch for osmo-pcu.
> I guess, that this patch should fix problem of receiving PACKET
> DOWNLINK ACK messages with unknown FN.
> Please, check it with your phones and notify me about results.
>
> 2012/11/1 Vladimir Rolbin <vrolbin at gmail.com>:
> > Hi, Ivan
> >
> > 1) First pls fix the following critical bug, readIndex  is modified by
> > readField cause delivered by reference, so every not first iteration
> it'll
> > have a bad value :
> >
> > *** ./DCCHDispatch.bug.cpp 2012-11-01 12:33:43.000000000 +0200
> > --- ./DCCHDispatch.cpp 2012-11-01 16:48:29.000000000 +0200
> > ***************
> > *** 469,474 ****
> > --- 469,475 ----
> >       }
> >       L3Frame *l3 = new L3Frame(msg->tail(8), UNIT_DATA);
> >       COUT("RX: [ BTS <- PCU ] AGCH: " << *l3);
> > +     readIndex = 0; //vr, fix
> >       l2Len = msg->readField(readIndex, len);
> >       l3->L2Length(l2Len);
> >       AGCH->send(l3);
> >
> >
> > or ( I like it more )
> >
> > *** ./DCCHDispatch.bug.cpp 2012-11-01 12:33:43.000000000 +0200
> > --- ./DCCHDispatch.fix0.cpp 2012-11-01 17:58:15.000000000 +0200
> > ***************
> > *** 431,438 ****
> >
> >    char buf[MAX_UDP_LENGTH];
> >
> > -  unsigned len = 6;
> > -  size_t readIndex = 0;
> >    size_t l2Len = 0;
> >
> >    // Send to PCU PhConnectInd primitive.
> > --- 431,436 ----
> > ***************
> > *** 469,475 ****
> >       }
> >       L3Frame *l3 = new L3Frame(msg->tail(8), UNIT_DATA);
> >       COUT("RX: [ BTS <- PCU ] AGCH: " << *l3);
> > !     l2Len = msg->readField(readIndex, len);
> >       l3->L2Length(l2Len);
> >       AGCH->send(l3);
> >       txPhDataIndCnf(*msg, gBTS.time());
> > --- 467,473 ----
> >       }
> >       L3Frame *l3 = new L3Frame(msg->tail(8), UNIT_DATA);
> >       COUT("RX: [ BTS <- PCU ] AGCH: " << *l3);
> > !     l2Len = msg->peekField(0, 6);
> >       l3->L2Length(l2Len);
> >       AGCH->send(l3);
> >       txPhDataIndCnf(*msg, gBTS.time());
> > ***************
> > *** 479,486 ****
> >       L3Frame *msg1 = new L3Frame(msg->tail(8*4), UNIT_DATA);
> >       L3Frame *msg2 = new L3Frame(msg->tail(8*4), UNIT_DATA);
> >       COUT("RX: [ BTS <- PCU ] PCH: " << *msg1);
> > !     readIndex = 24;
> > !     l2Len = msg->readField(readIndex, len);
> >       msg1->L2Length(l2Len);
> >       msg2->L2Length(l2Len);
> >       // HACK -- We send every page twice.
> > --- 477,483 ----
> >       L3Frame *msg1 = new L3Frame(msg->tail(8*4), UNIT_DATA);
> >       L3Frame *msg2 = new L3Frame(msg->tail(8*4), UNIT_DATA);
> >       COUT("RX: [ BTS <- PCU ] PCH: " << *msg1);
> > !     l2Len = msg->peekField(8*3, 6);
> >       msg1->L2Length(l2Len);
> >       msg2->L2Length(l2Len);
> >       // HACK -- We send every page twice.
> >
> >
> > I would reccomend also to fix BitVector.cpp known bug:
> > void BitVector::unpack(const unsigned char* src)
> > {
> >  // Assumes MSB-first packing.
> >  unsigned bytes = size()/8;
> >  for (unsigned i=0; i<bytes; i++) {
> >   fillField(i*8,src[i],8);
> >  }
> >  unsigned whole = bytes*8;
> >  unsigned rem = size() - whole;
> >  if (rem==0) return;
> >         fillField(whole,src[bytes] >> (8-rem),rem); //here
> > }
> >
> > USRPDevice.cpp known bug:
> > double USRPDevice::setTxGain(double dB) {
> >
> >    writeLock.lock();
> >    if (dB > maxTxGain()) dB = maxTxGain();
> >    if (dB < minTxGain()) dB = minTxGain();
> >    LOG(NOTICE) << "Setting TX gain to " << dB << " dB.";
> >    if (!m_dbTx->set_gain(dB)) // here
> >      LOG(ERR) << "Error setting TX gain";
> >    writeLock.unlock();
> >
> >    return dB;
> > }
> >
> > BSIC calculation:
> >
> > prim->u.info_ind.bsic = (gConfig.getNum("GSM.Identity.BSIC.NCC") << 3) |
> > gConfig.getNum("GSM.Identity.BSIC.BCC");
> >
> >
> >
> > 2) With up to date OpenBTS pulled from git today and critical fix only
> I've
> > got the results identical to session 2 and 3 I've recorded yesterday. I
> > attach the file with problematic scenario. I think you may recreate the
> > problem with every SonyErricson supporting 3G and GSM (my env is Suse
> 11.4
> > or Ubuntu 11.10, libusb_1_0 and libusrp-3.4.2).
> >
> > Regards,
> > Vladimir
> >
>
>
>
> --
> Regards,
> Ivan Kluchnikov.
> http://fairwaves.ru
>
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