p802_15_4csmaca.cc

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/********************************************/
/*     NS2 Simulator for IEEE 802.15.4      */
/*           (per P802.15.4/D18)            */
/*------------------------------------------*/
/* by:        Jianliang Zheng               */
/*        (zheng@ee.ccny.cuny.edu)          */
/*              Myung J. Lee                */
/*          (lee@ccny.cuny.edu)             */
/*        ~~~~~~~~~~~~~~~~~~~~~~~~~         */
/*           SAIT-CUNY Joint Lab            */
/********************************************/

// File:  p802_15_4csmaca.cc
// Mode:  C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t

// $Header: /nfs/jade/vint/CVSROOT/ns-2/wpan/p802_15_4csmaca.cc,v 1.2 2005/07/13 03:51:33 tomh Exp $

/*
 * Copyright (c) 2003-2004 Samsung Advanced Institute of Technology and
 * The City University of New York. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the Joint Lab of Samsung 
 *      Advanced Institute of Technology and The City University of New York.
 * 4. Neither the name of Samsung Advanced Institute of Technology nor of 
 *    The City University of New York may be used to endorse or promote 
 *    products derived from this software without specific prior written 
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE JOINT LAB OF SAMSUNG ADVANCED INSTITUTE
 * OF TECHNOLOGY AND THE CITY UNIVERSITY OF NEW YORK ``AS IS'' AND ANY EXPRESS 
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 
 * NO EVENT SHALL SAMSUNG ADVANCED INSTITUTE OR THE CITY UNIVERSITY OF NEW YORK 
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#include "p802_15_4csmaca.h"
#include "p802_15_4const.h"
#include "p802_15_4trace.h"


CsmaCA802_15_4::CsmaCA802_15_4(Phy802_15_4 *p, Mac802_15_4 *m)
{
    phy = p;
    mac = m;
    txPkt = 0;
    waitNextBeacon = false;
    backoffT = new macBackoffTimer(this);
    assert(backoffT);
    bcnOtherT = new macBeaconOtherTimer(this);
    assert(bcnOtherT);
    deferCCAT = new macDeferCCATimer(this);
    assert(deferCCAT);
}

CsmaCA802_15_4::~CsmaCA802_15_4()
{
    delete backoffT;
    delete bcnOtherT;
    delete deferCCAT;
}

void CsmaCA802_15_4::reset(void)
{
    if (beaconEnabled)
    {
        NB = 0;
        CW = 2;
        BE = mac->mpib.macMinBE;
        if ((mac->mpib.macBattLifeExt)&&(BE > 2))
            BE = 2;
    }
    else
    {
        NB = 0;
        BE = mac->mpib.macMinBE;
    }
}

double CsmaCA802_15_4::adjustTime(double wtime)
{
    //find the beginning point of CAP and adjust the scheduled time
    //if it comes before CAP
    double neg;
    double tmpf;

    assert(txPkt);
    if (!mac->toParent(txPkt))
    {
        if (mac->mpib.macBeaconOrder != 15)
        {
            /* Linux floating number compatibility
            neg = (CURRENT_TIME + wtime - bcnTxTime) - mac->beaconPeriods * bPeriod;
            */
            {
            tmpf = mac->beaconPeriods * bPeriod;
            tmpf = CURRENT_TIME - tmpf;
            tmpf += wtime;
            neg = tmpf - bcnTxTime;
            }

            if (neg < 0.0)
                wtime -= neg;
            return wtime;
        }
        else
            return wtime;
    }
    else
    {
        if (mac->macBeaconOrder2 != 15)
        {
            /* Linux floating number compatibility
            neg = (CURRENT_TIME + wtime - bcnRxTime) - mac->beaconPeriods2 * bPeriod;
            */
            {
            tmpf = mac->beaconPeriods2 * bPeriod;
            tmpf = CURRENT_TIME - tmpf;
            tmpf += wtime;
            neg = tmpf - bcnRxTime;
            }

            if (neg < 0.0)
                wtime -= neg;
            return wtime;
        }
        else
            return wtime;
    }
}

bool CsmaCA802_15_4::canProceed(double wtime, bool afterCCA)
{
    //check if can proceed within the current superframe
    //(in the case the node acts as both a coordinator and a device, both the superframes from and to this node should be taken into account)
    bool ok;
    UINT_16 t_bPeriods,t_CAP;
    double t_fCAP,t_CCATime,t_IFS,t_transacTime,bcnOtherTime,BI2;

    waitNextBeacon = false;
    wtime = mac->locateBoundary(mac->toParent(txPkt),wtime);
    if (!mac->toParent(txPkt))
    {
        if (mac->mpib.macBeaconOrder != 15)
        {
            if (mac->sfSpec.BLE)
                t_CAP = mac->getBattLifeExtSlotNum();
            else
                t_CAP = (mac->sfSpec.FinCAP + 1) * (mac->sfSpec.sd / aUnitBackoffPeriod) - mac->beaconPeriods;  //(mac->sfSpec.sd % aUnitBackoffPeriod) = 0

            /* Linux floating number compatibility
            t_bPeriods = (UINT_16)(((CURRENT_TIME + wtime - bcnTxTime) / bPeriod) - mac->beaconPeriods);
            */
            {
            double tmpf;
            tmpf = CURRENT_TIME + wtime;
            tmpf -= bcnTxTime;
            tmpf /= bPeriod;
            t_bPeriods = (UINT_16)(tmpf - mac->beaconPeriods);
            }

            /* Linux floating number compatibility
            if (fmod(CURRENT_TIME + wtime - bcnTxTime, bPeriod) > 0.0)
            */
            double tmpf;
            tmpf = CURRENT_TIME + wtime;
            tmpf -= bcnTxTime;
            if (fmod(tmpf, bPeriod) > 0.0)
                t_bPeriods++;
            bPeriodsLeft = t_bPeriods - t_CAP;
        }
        else
            bPeriodsLeft = -1;
    }
    else
    {
        if (mac->macBeaconOrder2 != 15)
        {
            BI2 = mac->sfSpec2.BI / phy->getRate('s');
            
            /* Linux floating number compatibility
            t_CAP = (UINT_16)((mac->macBcnRxTime + (mac->sfSpec2.FinCAP + 1) * mac->sfSpec2.sd ) / phy->getRate('s'));
            */
            {
            double tmpf;
            tmpf = (mac->sfSpec2.FinCAP + 1) * mac->sfSpec2.sd;
            tmpf += mac->macBcnRxTime;
            t_CAP = (UINT_16)(tmpf / phy->getRate('s'));
            }

            /* Linux floating number compatibility
            if (t_CAP + aMaxLostBeacons * BI2 < CURRENT_TIME)
            */
            double tmpf;
            tmpf = aMaxLostBeacons * BI2;
            if (t_CAP + tmpf < CURRENT_TIME)    
                bPeriodsLeft = -1;
            else
            {
                if (mac->sfSpec2.BLE)
                    t_CAP = mac->getBattLifeExtSlotNum();
                else
                    t_CAP = (mac->sfSpec2.FinCAP + 1) * (mac->sfSpec2.sd / aUnitBackoffPeriod) - mac->beaconPeriods2;   

                /* Linux floating number compatibility
                t_bPeriods = (UINT_16)(((CURRENT_TIME + wtime - bcnRxTime) / bPeriod) - mac->beaconPeriods2);
                */
                {
                double tmpf;
                tmpf = CURRENT_TIME + wtime;
                tmpf -= bcnRxTime;
                tmpf /= bPeriod;
                t_bPeriods = (UINT_16)(tmpf - mac->beaconPeriods2);
                }

                /* Linux floating number compatibility
                if (fmod(CURRENT_TIME + wtime - bcnRxTime, bPeriod) > 0.0)
                */
                double tmpf;
                tmpf = CURRENT_TIME + wtime;
                tmpf -= bcnRxTime;
                if (fmod(tmpf, bPeriod) > 0.0)
                    t_bPeriods++;
                bPeriodsLeft = t_bPeriods - t_CAP;
            }
        }
        else
            bPeriodsLeft = -1;
    }

    ok = true;
    if (bPeriodsLeft > 0)
        ok = false;
    else if (bPeriodsLeft == 0)
    {
        if ((!mac->toParent(txPkt))
        &&  (!mac->sfSpec.BLE))
            ok = false;
        else if ((mac->toParent(txPkt))
        &&  (!mac->sfSpec2.BLE))
            ok = false;
    }
    if (!ok)
    {
#ifdef DEBUG802_15_4
        fprintf(stdout,"[%s::%s][%f](node %d) cannot proceed: bPeriodsLeft = %d, orders = %d/%d/%d, type = %s, src = %d, dst = %d, uid = %d, mac_uid = %ld, size = %d\n",__FILE__,__FUNCTION__,CURRENT_TIME,mac->index_,bPeriodsLeft,mac->mpib.macBeaconOrder,mac->macBeaconOrder2,mac->macBeaconOrder3,wpan_pName(txPkt),p802_15_4macSA(txPkt),p802_15_4macDA(txPkt),ch->uid(),HDR_LRWPAN(txPkt)->uid,ch->size());
#endif
        if (mac->macBeaconOrder2 != 15)
        if (!mac->bcnRxT->busy())
            mac->bcnRxT->start();
        waitNextBeacon = true;
        return false;
    }

    //calculate the time needed to finish the transaction
    t_CCATime = 8 / phy->getRate('s');
    if (HDR_CMN(txPkt)->size() <= aMaxSIFSFrameSize)
        t_IFS = aMinSIFSPeriod;
    else
        t_IFS = aMinLIFSPeriod;
    t_IFS /= phy->getRate('s');
    t_transacTime  = mac->locateBoundary(mac->toParent(txPkt),wtime) - wtime;               //boundary location time -- should be 0 here, since we have already located the boundary
    if (!afterCCA)
    {
        t_transacTime += t_CCATime;                                 //first CCA time
        t_transacTime += mac->locateBoundary(mac->toParent(txPkt),t_transacTime) - (t_transacTime); //boundary location time for second CCA
        t_transacTime += t_CCATime;                                 //second CCA time
    }
    t_transacTime += mac->locateBoundary(mac->toParent(txPkt),t_transacTime) - (t_transacTime);     //boundary location time for transmission
    t_transacTime += phy->trxTime(txPkt);                                   //packet transmission time
    if (ackReq)
    {
        t_transacTime += mac->mpib.macAckWaitDuration/phy->getRate('s');                //ack. waiting time (this value does not include round trip propagation delay)
        t_transacTime += 2*max_pDelay;                                  //round trip propagation delay (802.15.4 ignores this, but it should be there even though it is very small)
        t_transacTime += t_IFS;                                     //IFS time -- not only ensure that the sender can finish the transaction, but also the receiver
        t_fCAP = mac->getCAP(true);

        /* Linux floating number compatibility
        if (CURRENT_TIME + wtime + t_transacTime > t_fCAP)
        */
        double tmpf;
        tmpf = CURRENT_TIME + wtime;
        tmpf += t_transacTime;
        if (tmpf > t_fCAP)
            ok = false;
        else
            ok= true;
    }
    else
    {
        //in this case, we need to handle individual CAP 
        ok = true;
        t_fCAP = mac->getCAPbyType(1);

        /* Linux floating number compatibility
        if (CURRENT_TIME + wtime + t_transacTime > t_fCAP)
        */
        double tmpf;
        tmpf = CURRENT_TIME + wtime;
        tmpf += t_transacTime;
        if (tmpf > t_fCAP)
            ok = false;
        if (ok)
        {
            t_fCAP = mac->getCAPbyType(2);
            t_transacTime += max_pDelay;                        //one-way trip propagation delay (802.15.4 ignores this, but it should be there even though it is very small)
            t_transacTime += 12/phy->getRate('s');                  //transceiver turn-around time (receiver may need to do this to transmit next beacon)
            t_transacTime += t_IFS;                         //IFS time -- not only ensure that the sender can finish the transaction, but also the receiver

            /* Linux floating number compatibility
            if (CURRENT_TIME + wtime + t_transacTime > t_fCAP)
            */
            double tmpf;
            tmpf = CURRENT_TIME + wtime;
            tmpf += t_transacTime;
            if (tmpf > t_fCAP)
                ok = false;
        }
        if (ok)
        {
            t_fCAP = mac->getCAPbyType(3);
            t_transacTime -= t_IFS;                         //the third node does not need to handle the transaction

            /* Linux floating number compatibility
            if (CURRENT_TIME + wtime + t_transacTime > t_fCAP)
            */
            double tmpf;
            tmpf = CURRENT_TIME + wtime;
            tmpf += t_transacTime;
            if (tmpf > t_fCAP)
                ok = false;
        }
    }

    //check if have enough CAP to finish the transaction
    if (!ok)
    {
        bPeriodsLeft = 0;
        if ((mac->mpib.macBeaconOrder == 15)
        &&  (mac->macBeaconOrder2 == 15)
        &&  (mac->macBeaconOrder3 != 15))
        {
            /* Linux floating number compatibility
            bcnOtherTime = (mac->macBcnOtherRxTime + mac->sfSpec3.BI) / phy->getRate('s');
            */
            {
            double tmpf;
            tmpf = (mac->macBcnOtherRxTime + mac->sfSpec3.BI);
            bcnOtherTime = tmpf / phy->getRate('s');
            }

            while (bcnOtherTime < CURRENT_TIME)
                bcnOtherTime += (mac->sfSpec3.BI / phy->getRate('s'));
            bcnOtherT->start(bcnOtherTime - CURRENT_TIME);
        }
#ifdef DEBUG802_15_4
    fprintf(stdout,"[%s::%s][%f](node %d) cannot proceed: orders = %d/%d/%d, type = %s, src = %d, dst = %d, uid = %d, mac_uid = %ld, size = %d\n",__FILE__,__FUNCTION__,CURRENT_TIME,mac->index_,mac->mpib.macBeaconOrder,mac->macBeaconOrder2,mac->macBeaconOrder3,wpan_pName(txPkt),p802_15_4macSA(txPkt),p802_15_4macDA(txPkt),ch->uid(),HDR_LRWPAN(txPkt)->uid,ch->size());
#endif
        if (mac->macBeaconOrder2 != 15)
        if (!mac->bcnRxT->busy())
            mac->bcnRxT->start();
        waitNextBeacon = true;
        return false;
    }
    else
    {
        bPeriodsLeft = -1;
        return true;
    }
}

void CsmaCA802_15_4::newBeacon(char trx)
{
    //this function will be called by MAC each time a new beacon received or sent within the current PAN
    double rate,wtime;

    if (!mac->txAck)
        mac->plme_set_trx_state_request(p_RX_ON);   

    if (bcnOtherT->busy())
        bcnOtherT->stop();

    //update values
    beaconEnabled = ((mac->mpib.macBeaconOrder != 15)||(mac->macBeaconOrder2 != 15));
    beaconOther = (mac->macBeaconOrder3 != 15);
    reset();    
    rate = phy->getRate('s');
    bcnTxTime = mac->macBcnTxTime / rate;
    bcnRxTime = mac->macBcnRxTime / rate;
    bPeriod = aUnitBackoffPeriod / rate;

    if (waitNextBeacon)
    if ((txPkt)
        && (!backoffT->busy()))
    {
        assert(bPeriodsLeft >= 0);
        if (bPeriodsLeft == 0)
        {
            wtime = adjustTime(0.0);
            if (canProceed(wtime));
                backoffHandler();   //no need to resume backoff
        }
        else
        {
            wtime = adjustTime(0.0);
            wtime += bPeriodsLeft * bPeriod;
            if (canProceed(wtime));
                backoffT->start(wtime);
        }
    }
    waitNextBeacon = false;
}

void CsmaCA802_15_4::start(bool firsttime,Packet *pkt,bool ackreq)
{
    bool backoff;
    double rate,wtime,BI2;


    if (mac->txAck)
    {
        mac->backoffStatus = 0;
        txPkt = 0;
        return;
    }

    assert(backoffT->busy() == 0);
    if (firsttime)
    {
        beaconEnabled = ((mac->mpib.macBeaconOrder != 15)||(mac->macBeaconOrder2 != 15));
        beaconOther = (mac->macBeaconOrder3 != 15);
        reset();    
        assert(txPkt == 0);
        txPkt = pkt;
        ackReq = ackreq;
        rate = phy->getRate('s');
        bPeriod = aUnitBackoffPeriod / rate;
        if (beaconEnabled)
        {
            bcnTxTime = mac->macBcnTxTime / rate;
            bcnRxTime = mac->macBcnRxTime / rate;
            //it's possible we missed some beacons
            BI2 = (mac->sfSpec2.BI / phy->getRate('s'));
            if (mac->macBeaconOrder2 != 15)
            while (bcnRxTime + BI2 < CURRENT_TIME)
                bcnRxTime += BI2;
        }
    }

    wtime = (Random::random() % (1<<BE)) * bPeriod;
    wtime = adjustTime(wtime);
    backoff = true;
    if (beaconEnabled||beaconOther)
    {
        if (beaconEnabled)
        if (firsttime)
            wtime = mac->locateBoundary(mac->toParent(txPkt),wtime);
        if (!canProceed(wtime))     
            backoff = false;
    }
    if (backoff)
        backoffT->start(wtime);
}

void CsmaCA802_15_4::cancel(void)
{
    if (bcnOtherT->busy())
        bcnOtherT->stop();
    else if (backoffT->busy())
        backoffT->stop();
    else if (deferCCAT->busy())
        deferCCAT->stop();
    else
        mac->taskP.taskStatus(TP_CCA_csmaca) = false;
    txPkt = 0;
}

void CsmaCA802_15_4::backoffHandler(void)
{
    mac->taskP.taskStatus(TP_RX_ON_csmaca) = true;
    mac->plme_set_trx_state_request(p_RX_ON);
}

void CsmaCA802_15_4::RX_ON_confirm(PHYenum status)
{
    double now,wtime;

    if (status != p_RX_ON)
    {
        if (status == p_BUSY_TX)
            mac->taskP.taskStatus(TP_RX_ON_csmaca) = true;
        else
            backoffHandler();
        return;
    }

    //locate backoff boundary if needed
    now = CURRENT_TIME;
    if (beaconEnabled)
        wtime = mac->locateBoundary(mac->toParent(txPkt),0.0);
    else
        wtime = 0.0;

    if (wtime == 0.0)
    {
        mac->taskP.taskStatus(TP_CCA_csmaca) = true;
        phy->PLME_CCA_request();
    }
    else
        deferCCAT->start(wtime);
}

void CsmaCA802_15_4::bcnOtherHandler(void)
{
    newBeacon('R');
}

void CsmaCA802_15_4::deferCCAHandler(void)
{
    mac->taskP.taskStatus(TP_CCA_csmaca) = true;
    phy->PLME_CCA_request();
}

void CsmaCA802_15_4::CCA_confirm(PHYenum status)
{
    //This function should be called when mac receiving CCA_confirm.
    bool idle;

    idle = (status == p_IDLE)?1:0;  
    if (idle)
    {
        if ((!beaconEnabled)&&(!beaconOther))
        {
            txPkt = 0;
            mac->csmacaCallBack(p_IDLE);
        }
        else
        {
            if (beaconEnabled)
                CW--;
            else
                CW = 0;
            if (CW == 0)
            {
                //timing condition may not still hold -- check again
                if (canProceed(0.0, true))
                {
                    txPkt = 0;
                    mac->csmacaCallBack(p_IDLE);
                }
                else    //postpone until next beacon sent or received
                {
                    if (beaconEnabled) CW = 2;
                    bPeriodsLeft = 0;
                }
            }
            else    //perform CCA again
                backoffHandler();
        }
    }
    else    //busy
    {
        if (beaconEnabled) CW = 2;
        NB++;
        if (NB > mac->mpib.macMaxCSMABackoffs)
        {
            txPkt = 0;
            mac->csmacaCallBack(p_BUSY);
        }
        else    //backoff again
        {
            BE++;
            if (BE > aMaxBE)
                BE = aMaxBE;
            start(false);
        }
    }
}

// End of file: p802_15_4csmaca.cc

---