Files
openbts-2.8/Transceiver52M/Transceiver.cpp
kurtis.heimerl 6f86e434c5 transceiver: make the transmit drive loop bus dependent
With the introduction of the B100, there is USB support
using UHD devices. The characteristics of the trasmit
side burst submissions are more reflective of the bus
type than the device or driver.

Use a fixed latency interval for network devices and the
adaptive underrun approach for USB devices - regardless
of driver or device type.

The GPMC based transport on the E100 appears unaffected
by either latency scheme, which defaults to network.

Signed-off-by: Thomas Tsou <ttsou@vt.edu>

git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2677 19bc5d8c-e614-43d4-8b26-e1612bc8e597
2011-11-26 03:18:55 +00:00

805 lines
23 KiB
C++

/*
* Copyright 2008, 2009, 2010 Free Software Foundation, Inc.
*
* This software is distributed under the terms of the GNU Public License.
* See the COPYING file in the main directory for details.
*
* This use of this software may be subject to additional restrictions.
* See the LEGAL file in the main directory for details.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
Compilation switches
TRANSMIT_LOGGING write every burst on the given slot to a log
*/
#include <stdio.h>
#include "Transceiver.h"
#include <Logger.h>
Transceiver::Transceiver(int wBasePort,
const char *TRXAddress,
int wSamplesPerSymbol,
GSM::Time wTransmitLatency,
RadioInterface *wRadioInterface)
:mDataSocket(wBasePort+2,TRXAddress,wBasePort+102),
mControlSocket(wBasePort+1,TRXAddress,wBasePort+101),
mClockSocket(wBasePort,TRXAddress,wBasePort+100)
{
//GSM::Time startTime(0,0);
//GSM::Time startTime(gHyperframe/2 - 4*216*60,0);
GSM::Time startTime(random() % gHyperframe,0);
mFIFOServiceLoopThread = new Thread(32768); ///< thread to push bursts into transmit FIFO
mControlServiceLoopThread = new Thread(32768); ///< thread to process control messages from GSM core
mTransmitPriorityQueueServiceLoopThread = new Thread(32768);///< thread to process transmit bursts from GSM core
mSamplesPerSymbol = wSamplesPerSymbol;
mRadioInterface = wRadioInterface;
mTransmitLatency = wTransmitLatency;
mTransmitDeadlineClock = startTime;
mLastClockUpdateTime = startTime;
mLatencyUpdateTime = startTime;
mRadioInterface->getClock()->set(startTime);
mMaxExpectedDelay = 0;
// generate pulse and setup up signal processing library
gsmPulse = generateGSMPulse(2,mSamplesPerSymbol);
LOG(DEBUG) << "gsmPulse: " << *gsmPulse;
sigProcLibSetup(mSamplesPerSymbol);
txFullScale = mRadioInterface->fullScaleInputValue();
rxFullScale = mRadioInterface->fullScaleOutputValue();
// initialize filler tables with dummy bursts, initialize other per-timeslot variables
for (int i = 0; i < 8; i++) {
signalVector* modBurst = modulateBurst(gDummyBurst,*gsmPulse,
8 + (i % 4 == 0),
mSamplesPerSymbol);
scaleVector(*modBurst,txFullScale);
fillerModulus[i]=26;
for (int j = 0; j < 102; j++) {
fillerTable[j][i] = new signalVector(*modBurst);
}
delete modBurst;
mChanType[i] = NONE;
channelResponse[i] = NULL;
DFEForward[i] = NULL;
DFEFeedback[i] = NULL;
channelEstimateTime[i] = startTime;
}
mOn = false;
mTxFreq = 0.0;
mRxFreq = 0.0;
mPower = -10;
mEnergyThreshold = 5.0; // based on empirical data
prevFalseDetectionTime = startTime;
}
Transceiver::~Transceiver()
{
delete gsmPulse;
sigProcLibDestroy();
mTransmitPriorityQueue.clear();
}
void Transceiver::addRadioVector(BitVector &burst,
int RSSI,
GSM::Time &wTime)
{
// modulate and stick into queue
signalVector* modBurst = modulateBurst(burst,*gsmPulse,
8 + (wTime.TN() % 4 == 0),
mSamplesPerSymbol);
scaleVector(*modBurst,txFullScale * pow(10,-RSSI/10));
radioVector *newVec = new radioVector(*modBurst,wTime);
mTransmitPriorityQueue.write(newVec);
delete modBurst;
}
#ifdef TRANSMIT_LOGGING
void Transceiver::unModulateVector(signalVector wVector)
{
SoftVector *burst = demodulateBurst(wVector,
*gsmPulse,
mSamplesPerSymbol,
1.0,0.0);
LOG(DEBUG) << "LOGGED BURST: " << *burst;
/*
unsigned char burstStr[gSlotLen+1];
SoftVector::iterator burstItr = burst->begin();
for (int i = 0; i < gSlotLen; i++) {
// FIXME: Demod bits are inverted!
burstStr[i] = (unsigned char) ((*burstItr++)*255.0);
}
burstStr[gSlotLen]='\0';
LOG(DEBUG) << "LOGGED BURST: " << burstStr;
*/
delete burst;
}
#endif
void Transceiver::pushRadioVector(GSM::Time &nowTime)
{
// dump stale bursts, if any
while (radioVector* staleBurst = mTransmitPriorityQueue.getStaleBurst(nowTime)) {
// Even if the burst is stale, put it in the fillter table.
// (It might be an idle pattern.)
LOG(NOTICE) << "dumping STALE burst in TRX->USRP interface";
const GSM::Time& nextTime = staleBurst->getTime();
int TN = nextTime.TN();
int modFN = nextTime.FN() % fillerModulus[TN];
delete fillerTable[modFN][TN];
fillerTable[modFN][TN] = staleBurst;
}
int TN = nowTime.TN();
int modFN = nowTime.FN() % fillerModulus[nowTime.TN()];
// if queue contains data at the desired timestamp, stick it into FIFO
if (radioVector *next = (radioVector*) mTransmitPriorityQueue.getCurrentBurst(nowTime)) {
LOG(DEBUG) << "transmitFIFO: wrote burst " << next << " at time: " << nowTime;
delete fillerTable[modFN][TN];
fillerTable[modFN][TN] = new signalVector(*(next));
mRadioInterface->driveTransmitRadio(*(next),(mChanType[TN]==NONE)); //fillerTable[modFN][TN]));
delete next;
#ifdef TRANSMIT_LOGGING
if (nowTime.TN()==TRANSMIT_LOGGING) {
unModulateVector(*(fillerTable[modFN][TN]));
}
#endif
return;
}
// otherwise, pull filler data, and push to radio FIFO
mRadioInterface->driveTransmitRadio(*(fillerTable[modFN][TN]),(mChanType[TN]==NONE));
#ifdef TRANSMIT_LOGGING
if (nowTime.TN()==TRANSMIT_LOGGING)
unModulateVector(*fillerTable[modFN][TN]);
#endif
}
void Transceiver::setModulus(int timeslot)
{
switch (mChanType[timeslot]) {
case NONE:
case I:
case II:
case III:
case FILL:
fillerModulus[timeslot] = 26;
break;
case IV:
case VI:
case V:
fillerModulus[timeslot] = 51;
break;
//case V:
case VII:
fillerModulus[timeslot] = 102;
break;
default:
break;
}
}
Transceiver::CorrType Transceiver::expectedCorrType(GSM::Time currTime)
{
unsigned burstTN = currTime.TN();
unsigned burstFN = currTime.FN();
switch (mChanType[burstTN]) {
case NONE:
return OFF;
break;
case FILL:
return IDLE;
break;
case I:
return TSC;
/*if (burstFN % 26 == 25)
return IDLE;
else
return TSC;*/
break;
case II:
if (burstFN % 2 == 1)
return IDLE;
else
return TSC;
break;
case III:
return TSC;
break;
case IV:
case VI:
return RACH;
break;
case V: {
int mod51 = burstFN % 51;
if ((mod51 <= 36) && (mod51 >= 14))
return RACH;
else if ((mod51 == 4) || (mod51 == 5))
return RACH;
else if ((mod51 == 45) || (mod51 == 46))
return RACH;
else
return TSC;
break;
}
case VII:
if ((burstFN % 51 <= 14) && (burstFN % 51 >= 12))
return IDLE;
else
return TSC;
break;
case LOOPBACK:
if ((burstFN % 51 <= 50) && (burstFN % 51 >=48))
return IDLE;
else
return TSC;
break;
default:
return OFF;
break;
}
}
SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime,
int &RSSI,
int &timingOffset)
{
bool needDFE = (mMaxExpectedDelay > 1);
radioVector *rxBurst = (radioVector *) mReceiveFIFO->get();
if (!rxBurst) return NULL;
LOG(DEBUG) << "receiveFIFO: read radio vector at time: " << rxBurst->getTime() << ", new size: " << mReceiveFIFO->size();
int timeslot = rxBurst->getTime().TN();
CorrType corrType = expectedCorrType(rxBurst->getTime());
if ((corrType==OFF) || (corrType==IDLE)) {
delete rxBurst;
return NULL;
}
// check to see if received burst has sufficient
signalVector *vectorBurst = rxBurst;
complex amplitude = 0.0;
float TOA = 0.0;
float avgPwr = 0.0;
if (!energyDetect(*vectorBurst,20*mSamplesPerSymbol,mEnergyThreshold,&avgPwr)) {
LOG(DEBUG) << "Estimated Energy: " << sqrt(avgPwr) << ", at time " << rxBurst->getTime();
double framesElapsed = rxBurst->getTime()-prevFalseDetectionTime;
if (framesElapsed > 50) { // if we haven't had any false detections for a while, lower threshold
mEnergyThreshold -= 10.0/10.0;
if (mEnergyThreshold < 0.0)
mEnergyThreshold = 0.0;
prevFalseDetectionTime = rxBurst->getTime();
}
delete rxBurst;
return NULL;
}
LOG(DEBUG) << "Estimated Energy: " << sqrt(avgPwr) << ", at time " << rxBurst->getTime();
// run the proper correlator
bool success = false;
if (corrType==TSC) {
LOG(DEBUG) << "looking for TSC at time: " << rxBurst->getTime();
signalVector *channelResp;
double framesElapsed = rxBurst->getTime()-channelEstimateTime[timeslot];
bool estimateChannel = false;
if ((framesElapsed > 50) || (channelResponse[timeslot]==NULL)) {
if (channelResponse[timeslot]) delete channelResponse[timeslot];
if (DFEForward[timeslot]) delete DFEForward[timeslot];
if (DFEFeedback[timeslot]) delete DFEFeedback[timeslot];
channelResponse[timeslot] = NULL;
DFEForward[timeslot] = NULL;
DFEFeedback[timeslot] = NULL;
estimateChannel = true;
}
if (!needDFE) estimateChannel = false;
float chanOffset;
success = analyzeTrafficBurst(*vectorBurst,
mTSC,
3.0,
mSamplesPerSymbol,
&amplitude,
&TOA,
mMaxExpectedDelay,
estimateChannel,
&channelResp,
&chanOffset);
if (success) {
LOG(DEBUG) << "FOUND TSC!!!!!! " << amplitude << " " << TOA;
mEnergyThreshold -= 1.0F/10.0F;
if (mEnergyThreshold < 0.0) mEnergyThreshold = 0.0;
SNRestimate[timeslot] = amplitude.norm2()/(mEnergyThreshold*mEnergyThreshold+1.0); // this is not highly accurate
if (estimateChannel) {
LOG(DEBUG) << "estimating channel...";
channelResponse[timeslot] = channelResp;
chanRespOffset[timeslot] = chanOffset;
chanRespAmplitude[timeslot] = amplitude;
scaleVector(*channelResp, complex(1.0,0.0)/amplitude);
designDFE(*channelResp, SNRestimate[timeslot], 7, &DFEForward[timeslot], &DFEFeedback[timeslot]);
channelEstimateTime[timeslot] = rxBurst->getTime();
LOG(DEBUG) << "SNR: " << SNRestimate[timeslot] << ", DFE forward: " << *DFEForward[timeslot] << ", DFE backward: " << *DFEFeedback[timeslot];
}
}
else {
double framesElapsed = rxBurst->getTime()-prevFalseDetectionTime;
LOG(DEBUG) << "wTime: " << rxBurst->getTime() << ", pTime: " << prevFalseDetectionTime << ", fElapsed: " << framesElapsed;
mEnergyThreshold += 10.0F/10.0F*exp(-framesElapsed);
prevFalseDetectionTime = rxBurst->getTime();
channelResponse[timeslot] = NULL;
}
}
else {
// RACH burst
success = detectRACHBurst(*vectorBurst,
5.0, // detection threshold
mSamplesPerSymbol,
&amplitude,
&TOA);
if (success) {
LOG(DEBUG) << "FOUND RACH!!!!!! " << amplitude << " " << TOA;
mEnergyThreshold -= (1.0F/10.0F);
if (mEnergyThreshold < 0.0) mEnergyThreshold = 0.0;
channelResponse[timeslot] = NULL;
}
else {
double framesElapsed = rxBurst->getTime()-prevFalseDetectionTime;
mEnergyThreshold += (1.0F/10.0F)*exp(-framesElapsed);
prevFalseDetectionTime = rxBurst->getTime();
}
}
LOG(DEBUG) << "energy Threshold = " << mEnergyThreshold;
// demodulate burst
SoftVector *burst = NULL;
if ((rxBurst) && (success)) {
if ((corrType==RACH) || (!needDFE)) {
burst = demodulateBurst(*vectorBurst,
*gsmPulse,
mSamplesPerSymbol,
amplitude,TOA);
}
else { // TSC
scaleVector(*vectorBurst,complex(1.0,0.0)/amplitude);
burst = equalizeBurst(*vectorBurst,
TOA-chanRespOffset[timeslot],
mSamplesPerSymbol,
*DFEForward[timeslot],
*DFEFeedback[timeslot]);
}
wTime = rxBurst->getTime();
RSSI = (int) floor(20.0*log10(rxFullScale/amplitude.abs()));
LOG(DEBUG) << "RSSI: " << RSSI;
timingOffset = (int) round(TOA*256.0/mSamplesPerSymbol);
}
//if (burst) LOG(DEBUG) << "burst: " << *burst << '\n';
delete rxBurst;
return burst;
}
void Transceiver::start()
{
mControlServiceLoopThread->start((void * (*)(void*))ControlServiceLoopAdapter,(void*) this);
}
void Transceiver::reset()
{
mTransmitPriorityQueue.clear();
//mTransmitFIFO->clear();
//mReceiveFIFO->clear();
}
void Transceiver::driveControl()
{
int MAX_PACKET_LENGTH = 100;
// check control socket
char buffer[MAX_PACKET_LENGTH];
int msgLen = -1;
buffer[0] = '\0';
msgLen = mControlSocket.read(buffer);
if (msgLen < 1) {
return;
}
char cmdcheck[4];
char command[MAX_PACKET_LENGTH];
char response[MAX_PACKET_LENGTH];
sscanf(buffer,"%3s %s",cmdcheck,command);
writeClockInterface();
if (strcmp(cmdcheck,"CMD")!=0) {
LOG(WARNING) << "bogus message on control interface";
return;
}
LOG(INFO) << "command is " << buffer;
if (strcmp(command,"POWEROFF")==0) {
// turn off transmitter/demod
sprintf(response,"RSP POWEROFF 0");
}
else if (strcmp(command,"POWERON")==0) {
// turn on transmitter/demod
if (!mTxFreq || !mRxFreq)
sprintf(response,"RSP POWERON 1");
else {
sprintf(response,"RSP POWERON 0");
if (!mOn) {
// Prepare for thread start
mPower = -20;
mRadioInterface->start();
generateRACHSequence(*gsmPulse,mSamplesPerSymbol);
// Start radio interface threads.
mFIFOServiceLoopThread->start((void * (*)(void*))FIFOServiceLoopAdapter,(void*) this);
mTransmitPriorityQueueServiceLoopThread->start((void * (*)(void*))TransmitPriorityQueueServiceLoopAdapter,(void*) this);
writeClockInterface();
mOn = true;
}
}
}
else if (strcmp(command,"SETMAXDLY")==0) {
//set expected maximum time-of-arrival
int maxDelay;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&maxDelay);
mMaxExpectedDelay = maxDelay; // 1 GSM symbol is approx. 1 km
sprintf(response,"RSP SETMAXDLY 0 %d",maxDelay);
}
else if (strcmp(command,"SETRXGAIN")==0) {
//set expected maximum time-of-arrival
int newGain;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&newGain);
newGain = mRadioInterface->setRxGain(newGain);
sprintf(response,"RSP SETRXGAIN 0 %d",newGain);
}
else if (strcmp(command,"NOISELEV")==0) {
if (mOn) {
sprintf(response,"RSP NOISELEV 0 %d",
(int) round(20.0*log10(rxFullScale/mEnergyThreshold)));
}
else {
sprintf(response,"RSP NOISELEV 1 0");
}
}
else if (strcmp(command,"SETPOWER")==0) {
// set output power in dB
int dbPwr;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&dbPwr);
if (!mOn)
sprintf(response,"RSP SETPOWER 1 %d",dbPwr);
else {
mPower = dbPwr;
mRadioInterface->setPowerAttenuation(dbPwr);
sprintf(response,"RSP SETPOWER 0 %d",dbPwr);
}
}
else if (strcmp(command,"ADJPOWER")==0) {
// adjust power in dB steps
int dbStep;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&dbStep);
if (!mOn)
sprintf(response,"RSP ADJPOWER 1 %d",mPower);
else {
mPower += dbStep;
sprintf(response,"RSP ADJPOWER 0 %d",mPower);
}
}
#define FREQOFFSET 0//11.2e3
else if (strcmp(command,"RXTUNE")==0) {
// tune receiver
int freqKhz;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&freqKhz);
mRxFreq = freqKhz*1.0e3+FREQOFFSET;
if (!mRadioInterface->tuneRx(mRxFreq)) {
LOG(ALERT) << "RX failed to tune";
sprintf(response,"RSP RXTUNE 1 %d",freqKhz);
}
else
sprintf(response,"RSP RXTUNE 0 %d",freqKhz);
}
else if (strcmp(command,"TXTUNE")==0) {
// tune txmtr
int freqKhz;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&freqKhz);
//freqKhz = 890e3;
mTxFreq = freqKhz*1.0e3+FREQOFFSET;
if (!mRadioInterface->tuneTx(mTxFreq)) {
LOG(ALERT) << "TX failed to tune";
sprintf(response,"RSP TXTUNE 1 %d",freqKhz);
}
else
sprintf(response,"RSP TXTUNE 0 %d",freqKhz);
}
else if (strcmp(command,"SETTSC")==0) {
// set TSC
int TSC;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&TSC);
if (mOn)
sprintf(response,"RSP SETTSC 1 %d",TSC);
else {
mTSC = TSC;
generateMidamble(*gsmPulse,mSamplesPerSymbol,TSC);
sprintf(response,"RSP SETTSC 0 %d",TSC);
}
}
else if (strcmp(command,"SETSLOT")==0) {
// set TSC
int corrCode;
int timeslot;
sscanf(buffer,"%3s %s %d %d",cmdcheck,command,&timeslot,&corrCode);
if ((timeslot < 0) || (timeslot > 7)) {
LOG(WARNING) << "bogus message on control interface";
sprintf(response,"RSP SETSLOT 1 %d %d",timeslot,corrCode);
return;
}
mChanType[timeslot] = (ChannelCombination) corrCode;
setModulus(timeslot);
sprintf(response,"RSP SETSLOT 0 %d %d",timeslot,corrCode);
}
else {
LOG(WARNING) << "bogus command " << command << " on control interface.";
}
mControlSocket.write(response,strlen(response)+1);
}
bool Transceiver::driveTransmitPriorityQueue()
{
char buffer[gSlotLen+50];
// check data socket
size_t msgLen = mDataSocket.read(buffer);
if (msgLen!=gSlotLen+1+4+1) {
LOG(ERR) << "badly formatted packet on GSM->TRX interface";
return false;
}
int timeSlot = (int) buffer[0];
uint64_t frameNum = 0;
for (int i = 0; i < 4; i++)
frameNum = (frameNum << 8) | (0x0ff & buffer[i+1]);
/*
if (GSM::Time(frameNum,timeSlot) > mTransmitDeadlineClock + GSM::Time(51,0)) {
// stale burst
//LOG(DEBUG) << "FAST! "<< GSM::Time(frameNum,timeSlot);
//writeClockInterface();
}*/
/*
DAB -- Just let these go through the demod.
if (GSM::Time(frameNum,timeSlot) < mTransmitDeadlineClock) {
// stale burst from GSM core
LOG(NOTICE) << "STALE packet on GSM->TRX interface at time "<< GSM::Time(frameNum,timeSlot);
return false;
}
*/
// periodically update GSM core clock
LOG(DEBUG) << "mTransmitDeadlineClock " << mTransmitDeadlineClock
<< " mLastClockUpdateTime " << mLastClockUpdateTime;
if (mTransmitDeadlineClock > mLastClockUpdateTime + GSM::Time(216,0))
writeClockInterface();
LOG(DEBUG) << "rcvd. burst at: " << GSM::Time(frameNum,timeSlot);
int RSSI = (int) buffer[5];
static BitVector newBurst(gSlotLen);
BitVector::iterator itr = newBurst.begin();
char *bufferItr = buffer+6;
while (itr < newBurst.end())
*itr++ = *bufferItr++;
GSM::Time currTime = GSM::Time(frameNum,timeSlot);
addRadioVector(newBurst,RSSI,currTime);
LOG(DEBUG) "added burst - time: " << currTime << ", RSSI: " << RSSI; // << ", data: " << newBurst;
return true;
}
void Transceiver::driveReceiveFIFO()
{
SoftVector *rxBurst = NULL;
int RSSI;
int TOA; // in 1/256 of a symbol
GSM::Time burstTime;
mRadioInterface->driveReceiveRadio();
rxBurst = pullRadioVector(burstTime,RSSI,TOA);
if (rxBurst) {
LOG(DEBUG) << "burst parameters: "
<< " time: " << burstTime
<< " RSSI: " << RSSI
<< " TOA: " << TOA
<< " bits: " << *rxBurst;
char burstString[gSlotLen+10];
burstString[0] = burstTime.TN();
for (int i = 0; i < 4; i++)
burstString[1+i] = (burstTime.FN() >> ((3-i)*8)) & 0x0ff;
burstString[5] = RSSI;
burstString[6] = (TOA >> 8) & 0x0ff;
burstString[7] = TOA & 0x0ff;
SoftVector::iterator burstItr = rxBurst->begin();
for (unsigned int i = 0; i < gSlotLen; i++) {
burstString[8+i] =(char) round((*burstItr++)*255.0);
}
burstString[gSlotLen+9] = '\0';
delete rxBurst;
mDataSocket.write(burstString,gSlotLen+10);
}
}
void Transceiver::driveTransmitFIFO()
{
/**
Features a carefully controlled latency mechanism, to
assure that transmit packets arrive at the radio/USRP
before they need to be transmitted.
Deadline clock indicates the burst that needs to be
pushed into the FIFO right NOW. If transmit queue does
not have a burst, stick in filler data.
*/
RadioClock *radioClock = (mRadioInterface->getClock());
if (mOn) {
//radioClock->wait(); // wait until clock updates
LOG(DEBUG) << "radio clock " << radioClock->get();
while (radioClock->get() + mTransmitLatency > mTransmitDeadlineClock) {
// if underrun, then we're not providing bursts to radio/USRP fast
// enough. Need to increase latency by one GSM frame.
if (mRadioInterface->getBus() == RadioDevice::USB) {
if (mRadioInterface->isUnderrun()) {
// only do latency update every 10 frames, so we don't over update
if (radioClock->get() > mLatencyUpdateTime + GSM::Time(10,0)) {
mTransmitLatency = mTransmitLatency + GSM::Time(1,0);
LOG(INFO) << "new latency: " << mTransmitLatency;
mLatencyUpdateTime = radioClock->get();
}
}
else {
// if underrun hasn't occurred in the last sec (216 frames) drop
// transmit latency by a timeslot
if (mTransmitLatency > GSM::Time(1,1)) {
if (radioClock->get() > mLatencyUpdateTime + GSM::Time(216,0)) {
mTransmitLatency.decTN();
LOG(INFO) << "reduced latency: " << mTransmitLatency;
mLatencyUpdateTime = radioClock->get();
}
}
}
}
// time to push burst to transmit FIFO
pushRadioVector(mTransmitDeadlineClock);
mTransmitDeadlineClock.incTN();
}
}
// FIXME -- This should not be a hard spin.
// But any delay here causes us to throw omni_thread_fatal.
//else radioClock->wait();
}
void Transceiver::writeClockInterface()
{
char command[50];
// FIXME -- This should be adaptive.
sprintf(command,"IND CLOCK %llu",(unsigned long long) (mTransmitDeadlineClock.FN()+2));
LOG(INFO) << "ClockInterface: sending " << command;
mClockSocket.write(command,strlen(command)+1);
mLastClockUpdateTime = mTransmitDeadlineClock;
}
void *FIFOServiceLoopAdapter(Transceiver *transceiver)
{
transceiver->setPriority();
while (1) {
transceiver->driveReceiveFIFO();
transceiver->driveTransmitFIFO();
pthread_testcancel();
}
return NULL;
}
void *ControlServiceLoopAdapter(Transceiver *transceiver)
{
while (1) {
transceiver->driveControl();
pthread_testcancel();
}
return NULL;
}
void *TransmitPriorityQueueServiceLoopAdapter(Transceiver *transceiver)
{
while (1) {
bool stale = false;
// Flush the UDP packets until a successful transfer.
while (!transceiver->driveTransmitPriorityQueue()) {
stale = true;
}
if (stale) {
// If a packet was stale, remind the GSM stack of the clock.
transceiver->writeClockInterface();
}
pthread_testcancel();
}
return NULL;
}