wireless-phy.cc

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- 
 *
 * Copyright (c) 1996 Regents of the University of California.
 * All rights reserved.
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 * are met:
 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Computer Systems
 *      Engineering Group at Lawrence Berkeley Laboratory and the Daedalus
 *      research group at UC Berkeley.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * 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.
 *
 * $Header: /nfs/jade/vint/CVSROOT/ns-2/mac/wireless-phy.cc,v 1.19 2002/12/11 01:22:52 difa Exp $
 *
 * Ported from CMU/Monarch's code, nov'98 -Padma Haldar.
 * wireless-phy.cc
 */

#include <math.h>

#include <packet.h>

#include <mobilenode.h>
#include <phy.h>
#include <propagation.h>
#include <modulation.h>
#include <omni-antenna.h>
#include <wireless-phy.h>
#include <packet.h>
#include <ip.h>
#include <agent.h>
#include <trace.h>

#include "diffusion/diff_header.h"

#define max(a,b) (((a)<(b))?(b):(a))

void Idle_Timer::expire(Event *) {
        a_->UpdateIdleEnergy();
}


/* ======================================================================
   WirelessPhy Interface
   ====================================================================== */
static class WirelessPhyClass: public TclClass {
public:
        WirelessPhyClass() : TclClass("Phy/WirelessPhy") {}
        TclObject* create(int, const char*const*) {
                return (new WirelessPhy);
        }
} class_WirelessPhy;


WirelessPhy::WirelessPhy() : Phy(), idle_timer_(this), status_(IDLE)
{
        /*
         *  It sounds like 10db should be the capture threshold.
         *
         *  If a node is presently receiving a packet a a power level
         *  Pa, and a packet at power level Pb arrives, the following
         *  comparion must be made to determine whether or not capture
         *  occurs:
         *
         *    10 * log(Pa) - 10 * log(Pb) > 10db
         *
         *  OR equivalently
         *
         *    Pa/Pb > 10.
         *
         */
        bind("CPThresh_", &CPThresh_);
        bind("CSThresh_", &CSThresh_);
        bind("RXThresh_", &RXThresh_);
        //bind("bandwidth_", &bandwidth_);
        bind("Pt_", &Pt_);
        bind("freq_", &freq_);
        bind("L_", &L_);
        
        lambda_ = SPEED_OF_LIGHT / freq_;

        node_ = 0;
        ant_ = 0;
        propagation_ = 0;
        modulation_ = 0;

        // Assume AT&T's Wavelan PCMCIA card -- Chalermek
        //      Pt_ = 8.5872e-4; // For 40m transmission range.
        //      Pt_ = 7.214e-3;  // For 100m transmission range.
        //      Pt_ = 0.2818; // For 250m transmission range.
        //      Pt_ = pow(10, 2.45) * 1e-3;         // 24.5 dbm, ~ 281.8mw
        
        Pt_consume_ = 0.660;  // 1.6 W drained power for transmission
        Pr_consume_ = 0.395;  // 1.2 W drained power for reception

        //      P_idle_ = 0.035; // 1.15 W drained power for idle

        P_idle_ = 0.0;

        channel_idle_time_ = NOW;
        update_energy_time_ = NOW;
        last_send_time_ = NOW;
        
        idle_timer_.resched(1.0);
}

int
WirelessPhy::command(int argc, const char*const* argv)
{
        TclObject *obj; 

        if (argc==2) {
                if (strcasecmp(argv[1], "NodeOn") == 0) {
                        if (em() == NULL) 
                                return TCL_OK;
                        if (NOW > update_energy_time_) {
                                update_energy_time_ = NOW;
                        }
                        return TCL_OK;
                } else if (strcasecmp(argv[1], "NodeOff") == 0) {
                        if (em() == NULL) 
                                return TCL_OK;
                        if (NOW > update_energy_time_) {
                                em()->DecrIdleEnergy(NOW-update_energy_time_,
                                                     P_idle_);
                                update_energy_time_ = NOW;
                        }
                        return TCL_OK;
                }
        } else if(argc == 3) {
                if (strcasecmp(argv[1], "setTxPower") == 0) {
                        Pt_consume_ = atof(argv[2]);
                        return TCL_OK;
                } else if (strcasecmp(argv[1], "setRxPower") == 0) {
                        Pr_consume_ = atof(argv[2]);
                        return TCL_OK;
                } else if (strcasecmp(argv[1], "setIdlePower") == 0) {
                        P_idle_ = atof(argv[2]);
                        return TCL_OK;
                } else if( (obj = TclObject::lookup(argv[2])) == 0) {
                        fprintf(stderr,"WirelessPhy: %s lookup of %s failed\n", 
                                argv[1], argv[2]);
                        return TCL_ERROR;
                } else if (strcmp(argv[1], "propagation") == 0) {
                        assert(propagation_ == 0);
                        propagation_ = (Propagation*) obj;
                        return TCL_OK;
                } else if (strcasecmp(argv[1], "antenna") == 0) {
                        ant_ = (Antenna*) obj;
                        return TCL_OK;
                } else if (strcasecmp(argv[1], "node") == 0) {
                        assert(node_ == 0);
                        node_ = (Node *)obj;
                        return TCL_OK;
                }
        }
        return Phy::command(argc,argv);
}
 
void 
WirelessPhy::sendDown(Packet *p)
{
        /*
         * Sanity Check
         */
        assert(initialized());
        
        if (em()) 
                if ((em()->node_on() != true) || (em()->sleep())) {
                        Packet::free(p);
                        return;
                }

        /*
         * Decrease node's energy
         */
        if(em()) {
                if (em()->energy() > 0) {
                        //double txtime = (8.*hdr_cmn::access(p)->size())/bandwidth_;
                    double txtime = hdr_cmn::access(p)->txtime();
                    double start_time = max(channel_idle_time_, NOW);
                    double end_time = max(channel_idle_time_, NOW+txtime);
                    double actual_txtime = end_time-start_time;

                    if (start_time > update_energy_time_) {
                            em()->DecrIdleEnergy(start_time - 
                                                 update_energy_time_, P_idle_);
                            update_energy_time_ = start_time;
                    }

                    /* It turns out that MAC sends packet even though, it's
                       receiving some packets.
                    
                    if (txtime-actual_txtime > 0.000001) {
                            fprintf(stderr,"Something may be wrong at MAC\n");
                            fprintf(stderr,"act_tx = %lf, tx = %lf\n", actual_txtime, txtime);
                    }
                    */

                   // Sanity check
                   double temp = max(NOW,last_send_time_);

                   /*
                   if (NOW < last_send_time_) {
                           fprintf(stderr,"Argggg !! Overlapping transmission. NOW %lf last %lf temp %lf\n", NOW, last_send_time_, temp);
                   }
                   */
                   
                   double begin_adjust_time = min(channel_idle_time_, temp);
                   double finish_adjust_time = min(channel_idle_time_, NOW+txtime);
                   double gap_adjust_time = finish_adjust_time - begin_adjust_time;
                   if (gap_adjust_time < 0.0) {
                           fprintf(stderr,"What the heck ! negative gap time.\n");
                   }

                   if ((gap_adjust_time > 0.0) && (status_ == RECV)) {
                           em()->DecrTxEnergy(gap_adjust_time,
                                              Pt_consume_-Pr_consume_);
                   }

                   em()->DecrTxEnergy(actual_txtime,Pt_consume_);
                   if (end_time > channel_idle_time_) {
                           status_ = SEND;
                   }
                                                        
                   last_send_time_ = NOW+txtime;
                   channel_idle_time_ = end_time;
                   update_energy_time_ = end_time;

                   if (em()->energy() <= 0) {
                           em()->setenergy(0);
                           ((MobileNode*)node())->log_energy(0);
                   }

                } else {
                        Packet::free(p);
                        return;
                }
        }

        /*
         *  Stamp the packet with the interface arguments
         */
        p->txinfo_.stamp((MobileNode*)node(), ant_->copy(), Pt_, lambda_);

        // Send the packet
        channel_->recv(p, this);
}

int 
WirelessPhy::sendUp(Packet *p)
{
        /*
         * Sanity Check
         */
        assert(initialized());

        PacketStamp s;
        double Pr;
        int pkt_recvd = 0;
        
        // if the node is in sleeping mode, drop the packet simply
        if (em()) 
                if (em()->sleep() || (em()->node_on() != true)) {
                        pkt_recvd = 0;
                        goto DONE;
                }
        
        // if the energy goes to ZERO, drop the packet simply
        if (em()) {
                if (em()->energy() <= 0) {
                        pkt_recvd = 0;
                        goto DONE;
                }
        }

        if(propagation_) {
                s.stamp((MobileNode*)node(), ant_, 0, lambda_);
                Pr = propagation_->Pr(&p->txinfo_, &s, this);
                if (Pr < CSThresh_) {
                        pkt_recvd = 0;
                        goto DONE;
                }
                if (Pr < RXThresh_) {
                        /*
                         * We can detect, but not successfully receive
                         * this packet.
                         */
                        hdr_cmn *hdr = HDR_CMN(p);
                        hdr->error() = 1;
#if DEBUG > 3
                        printf("SM %f.9 _%d_ drop pkt from %d low POWER %e/%e\n",
                               Scheduler::instance().clock(), node()->index(),
                               p->txinfo_.getNode()->index(),
                               Pr,RXThresh);
#endif
                }
        }
        if(modulation_) {
                hdr_cmn *hdr = HDR_CMN(p);
                hdr->error() = modulation_->BitError(Pr);
        }
        
        /*
         * The MAC layer must be notified of the packet reception
         * now - ie; when the first bit has been detected - so that
         * it can properly do Collision Avoidance / Detection.
         */
        pkt_recvd = 1;

DONE:
        p->txinfo_.getAntenna()->release();

        /* WILD HACK: The following two variables are a wild hack.
           They will go away in the next release...
           They're used by the mac-802_11 object to determine
           capture.  This will be moved into the net-if family of 
           objects in the future. */
        p->txinfo_.RxPr = Pr;
        p->txinfo_.CPThresh = pow(10,CPThresh_/10); /* CPThresh_ is in db */

        /*
         * Decrease energy if packet successfully received
         */
        if(pkt_recvd && em()) {
                //double rcvtime = (8. * hdr_cmn::access(p)->size())/bandwidth_;
                double rcvtime = hdr_cmn::access(p)->txtime();
                // no way to reach here if the energy level < 0
                
                /*
                  node()->add_rcvtime(rcvtime);   
                  em()->DecrRcvEnergy(rcvtime,Pr_consume_);
                */

                double start_time = max(channel_idle_time_, NOW);
                double end_time = max(channel_idle_time_, NOW+rcvtime);
                double actual_rcvtime = end_time-start_time;

                if (start_time > update_energy_time_) {
                        em()->DecrIdleEnergy(start_time-update_energy_time_,
                                             P_idle_);
                        update_energy_time_ = start_time;
                }
                
                em()->DecrRcvEnergy(actual_rcvtime,Pr_consume_);
                if (end_time > channel_idle_time_) {
                        status_ = RECV;
                }

                channel_idle_time_ = end_time;
                update_energy_time_ = end_time;

                /*
                  hdr_diff *dfh = HDR_DIFF(p);
                  printf("Node %d receives (%d, %d, %d) energy %lf.\n",
                  node()->address(), dfh->sender_id.addr_, 
                  dfh->sender_id.port_, dfh->pk_num, node()->energy());
                */
                
                if (em()->energy() <= 0) {  
                        // saying node died
                        em()->setenergy(0);
                        ((MobileNode*)node())->log_energy(0);
                }
        }
        
        return pkt_recvd;
}

void
WirelessPhy::node_on()
{
        if (em() == NULL)
            return;     
        if (NOW > update_energy_time_) {
            update_energy_time_ = NOW;
        }
}

void 
WirelessPhy::node_off()
{
        if (em() == NULL)
            return;
        if (NOW > update_energy_time_) {
            em()->DecrIdleEnergy(NOW-update_energy_time_,
                                P_idle_);
            update_energy_time_ = NOW;
        }
}

void
WirelessPhy::dump(void) const
{
        Phy::dump();
        fprintf(stdout,
                "\tPt: %f, Gt: %f, Gr: %f, lambda: %f, L: %f\n",
                Pt_, ant_->getTxGain(0,0,0,lambda_), ant_->getRxGain(0,0,0,lambda_), lambda_, L_);
        //fprintf(stdout, "\tbandwidth: %f\n", bandwidth_);
        fprintf(stdout, "--------------------------------------------------\n");
}


void WirelessPhy::UpdateIdleEnergy()
{
        if (em() == NULL) {
                return;
        }
        if (NOW > update_energy_time_ && em()->node_on()) {
                  em()-> DecrIdleEnergy(NOW-update_energy_time_,
                                        P_idle_);
                  update_energy_time_ = NOW;
        }

        // log node energy
        if (em()->energy() > 0) {
                ((MobileNode *)node_)->log_energy(1);
        } else {
                ((MobileNode *)node_)->log_energy(0);   
        }

        idle_timer_.resched(10.0);
}

---