Osmocom GSM/GPRS/EGPRS transceiver, originally forked from OpenBTS transceiver. For building SDR based GSM BTS with osmo-bts-trx.
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/**@file Common-use GSM declarations, most from the GSM 04.xx and 05.xx series. */
/*
* Copyright 2008-2011 Free Software Foundation, Inc.
*
* SPDX-License-Identifier: AGPL-3.0+
*
* This software is distributed under the terms of the GNU Affero 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 Affero 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef GSMCOMMON_H
#define GSMCOMMON_H
#include <stdlib.h>
#include <sys/time.h>
#include <ostream>
#include <vector>
#include <Threads.h>
#include <Timeval.h>
#include <BitVector.h>
namespace GSM {
/**@namespace GSM This namespace covers L1 FEC, L2 and L3 message translation. */
/** GSM Training sequences from GSM 05.02 5.2.3. */
extern const BitVector gTrainingSequence[];
extern const BitVector gEdgeTrainingSequence[];
/** C0T0 filler burst, GSM 05.02, 5.2.6 */
extern const BitVector gDummyBurst;
/** Random access burst synch. sequence */
extern const BitVector gRACHSynchSequenceTS0;
extern const BitVector gRACHSynchSequenceTS1;
extern const BitVector gRACHSynchSequenceTS2;
/** Random access burst synch. sequence, GSM 05.02 5.2.7 */
extern const BitVector gRACHBurst;
/**@name Modulus operations for frame numbers. */
//@{
/** The GSM hyperframe is largest time period in the GSM system, GSM 05.02 4.3.3. */
const uint32_t gHyperframe = 2048UL * 26UL * 51UL;
/** Get a clock difference, within the modulus, v1-v2. */
int32_t FNDelta(int32_t v1, int32_t v2);
/**
Compare two frame clock values.
@return 1 if v1>v2, -1 if v1<v2, 0 if v1==v2
*/
int FNCompare(int32_t v1, int32_t v2);
//@}
/**
GSM frame clock value. GSM 05.02 4.3
No internal thread sync.
*/
class Time {
private:
int mFN; ///< frame number in the hyperframe
int mTN; ///< timeslot number
public:
Time(int wFN=0, int wTN=0)
:mFN(wFN),mTN(wTN)
{ }
/** Move the time forward to a given position in a given modulus. */
void rollForward(unsigned wFN, unsigned modulus)
{
assert(modulus<gHyperframe);
while ((mFN % modulus) != wFN) mFN=(mFN+1)%gHyperframe;
}
/**@name Accessors. */
//@{
int FN() const { return mFN; }
void FN(unsigned wFN) { mFN = wFN; }
unsigned TN() const { return mTN; }
void TN(unsigned wTN) { mTN=wTN; }
//@}
/**@name Arithmetic. */
//@{
Time& operator++()
{
mFN = (mFN+1) % gHyperframe;
return *this;
}
Time& decTN(unsigned step=1)
{
assert(step<=8);
mTN -= step;
if (mTN<0) {
mTN+=8;
mFN-=1;
if (mFN<0) mFN+=gHyperframe;
}
return *this;
}
Time& incTN(unsigned step=1)
{
assert(step<=8);
mTN += step;
if (mTN>7) {
mTN-=8;
mFN = (mFN+1) % gHyperframe;
}
return *this;
}
Time& operator+=(int step)
{
// Remember the step might be negative.
mFN += step;
if (mFN<0) mFN+=gHyperframe;
mFN = mFN % gHyperframe;
return *this;
}
Time operator-(int step) const
{ return operator+(-step); }
Time operator+(int step) const
{
Time newVal = *this;
newVal += step;
return newVal;
}
Time operator+(const Time& other) const
{
unsigned newTN = (mTN + other.mTN) % 8;
uint64_t newFN = (mFN+other.mFN + (mTN + other.mTN)/8) % gHyperframe;
return Time(newFN,newTN);
}
int operator-(const Time& other) const
{
return FNDelta(mFN,other.mFN);
}
//@}
/**@name Comparisons. */
//@{
bool operator<(const Time& other) const
{
if (mFN==other.mFN) return (mTN<other.mTN);
return FNCompare(mFN,other.mFN)<0;
}
bool operator>(const Time& other) const
{
if (mFN==other.mFN) return (mTN>other.mTN);
return FNCompare(mFN,other.mFN)>0;
}
bool operator<=(const Time& other) const
{
if (mFN==other.mFN) return (mTN<=other.mTN);
return FNCompare(mFN,other.mFN)<=0;
}
bool operator>=(const Time& other) const
{
if (mFN==other.mFN) return (mTN>=other.mTN);
return FNCompare(mFN,other.mFN)>=0;
}
bool operator==(const Time& other) const
{
return (mFN == other.mFN) && (mTN==other.mTN);
}
//@}
/**@name Standard derivations. */
//@{
/** GSM 05.02 3.3.2.2.1 */
unsigned SFN() const { return mFN / (26*51); }
/** GSM 05.02 3.3.2.2.1 */
unsigned T1() const { return SFN() % 2048; }
/** GSM 05.02 3.3.2.2.1 */
unsigned T2() const { return mFN % 26; }
/** GSM 05.02 3.3.2.2.1 */
unsigned T3() const { return mFN % 51; }
/** GSM 05.02 3.3.2.2.1. */
unsigned T3p() const { return (T3()-1)/10; }
/** GSM 05.02 6.3.1.3. */
unsigned TC() const { return (FN()/51) % 8; }
/** GSM 04.08 10.5.2.30. */
unsigned T1p() const { return SFN() % 32; }
/** GSM 05.02 6.2.3 */
unsigned T1R() const { return T1() % 64; }
//@}
};
std::ostream& operator<<(std::ostream& os, const Time& ts);
}; // namespace GSM
#endif
// vim: ts=4 sw=4