lorawan-mac.cc

Go to the documentation of this file.

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2017 University of Padova
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Davide Magrin <magrinda@dei.unipd.it>
 *
 * Modified by: Bastien Tauran <bastien.tauran@viveris.fr>
 */
 
#include "lorawan-mac.h"
 
#include "ns3/log.h"
 
#include <algorithm>
#include <cmath>
#include <vector>
 
namespace ns3
{
 
NS_LOG_COMPONENT_DEFINE("LorawanMac");
 
NS_OBJECT_ENSURE_REGISTERED(LorawanMac);
 
TypeId
LorawanMac::GetTypeId(void)
{
    static TypeId tid =
        TypeId("ns3::LorawanMac")
            .SetParent<SatMac>()
            .AddTraceSource("SentNewPacket",
                            "Trace source indicating a new packet "
                            "arrived at the MAC layer",
                            MakeTraceSourceAccessor(&LorawanMac::m_sentNewPacket),
                            "ns3::Packet::TracedCallback")
            .AddTraceSource("ReceivedPacket",
                            "Trace source indicating a packet "
                            "was correctly received at the MAC layer",
                            MakeTraceSourceAccessor(&LorawanMac::m_receivedPacket),
                            "ns3::Packet::TracedCallback")
            .AddTraceSource("CannotSendBecauseDutyCycle",
                            "Trace source indicating a packet "
                            "could not be sent immediately because of duty cycle limitations",
                            MakeTraceSourceAccessor(&LorawanMac::m_cannotSendBecauseDutyCycle),
                            "ns3::Packet::TracedCallback");
    return tid;
}
 
LorawanMac::LorawanMac()
    : m_isRegenerative(false)
{
    NS_FATAL_ERROR("Default constructor not in use");
}
 
LorawanMac::LorawanMac(uint32_t satId, uint32_t beamId)
    : SatMac(satId, beamId),
      m_beamId(beamId),
      m_isRegenerative(false)
{
    NS_LOG_FUNCTION(this);
}
 
LorawanMac::~LorawanMac()
{
    NS_LOG_FUNCTION(this);
}
 
void
LorawanMac::Send(Ptr<Packet> packet, const Address& dest, uint16_t protocolNumber)
{
    Send(packet);
}
 
void
LorawanMac::SetDevice(Ptr<NetDevice> device)
{
    m_device = device;
}
 
Ptr<NetDevice>
LorawanMac::GetDevice(void)
{
    return m_device;
}
 
Ptr<SatPhy>
LorawanMac::GetPhy(void)
{
    return m_phy;
}
 
void
LorawanMac::SetPhy(Ptr<SatPhy> phy)
{
    // Set the phy
    m_phy = phy;
    Ptr<SatLoraPhyTx> phyLoraTx = DynamicCast<SatLoraPhyTx>(m_phy->GetPhyTx());
    NS_ASSERT_MSG(phyLoraTx != nullptr, "Lorawan MAC does not have a SatLoraPhyTx instance");
    phyLoraTx->SetTxFinishedCallback(MakeCallback(&LorawanMac::TxFinished, this));
}
 
LoraLogicalChannelHelper
LorawanMac::GetLoraLogicalChannelHelper(void)
{
    return m_channelHelper;
}
 
void
LorawanMac::SetLoraLogicalChannelHelper(LoraLogicalChannelHelper helper)
{
    m_channelHelper = helper;
}
 
uint8_t
LorawanMac::GetSfFromDataRate(uint8_t dataRate)
{
    NS_LOG_FUNCTION(this << unsigned(dataRate));
 
    // Check we are in range
    if (dataRate >= m_sfForDataRate.size())
    {
        return 0;
    }
 
    return m_sfForDataRate.at(dataRate);
}
 
double
LorawanMac::GetBandwidthFromDataRate(uint8_t dataRate)
{
    NS_LOG_FUNCTION(this << unsigned(dataRate));
 
    // Check we are in range
    if (dataRate > m_bandwidthForDataRate.size())
    {
        return 0;
    }
 
    return m_bandwidthForDataRate.at(dataRate);
}
 
double
LorawanMac::GetDbmForTxPower(uint8_t txPower)
{
    NS_LOG_FUNCTION(this << unsigned(txPower));
 
    if (txPower > m_txDbmForTxPower.size())
    {
        return 0;
    }
 
    return m_txDbmForTxPower.at(txPower);
}
 
Time
LorawanMac::GetOnAirTime(Ptr<Packet> packet, LoraTxParameters txParams)
{
    NS_LOG_FUNCTION(packet);
 
    // The contents of this function are based on [1].
    // [1] SX1272 LoRa modem designer's guide.
 
    // Compute the symbol duration
    // Bandwidth is in Hz
    double tSym = pow(2, int(txParams.sf)) / (txParams.bandwidthHz);
 
    // Compute the preamble duration
    double tPreamble = (double(txParams.nPreamble) + 4.25) * tSym;
 
    // Payload size
    uint32_t pl = packet->GetSize(); // Size in bytes
    NS_LOG_DEBUG("Packet of size " << pl << " bytes");
 
    // This step is needed since the formula deals with double values.
    // de = 1 when the low data rate optimization is enabled, 0 otherwise
    // h = 1 when header is implicit, 0 otherwise
    double de = txParams.lowDataRateOptimizationEnabled ? 1 : 0;
    double h = txParams.headerDisabled ? 1 : 0;
    double crc = txParams.crcEnabled ? 1 : 0;
 
    // num and den refer to numerator and denominator of the time on air formula
    double num = 8 * pl - 4 * txParams.sf + 28 + 16 * crc - 20 * h;
    double den = (txParams.sf - 2 * de) * txParams.codingRate;
    double payloadSymbNb = 8 + std::max(std::ceil(num / den), double(0));
 
    // Time to transmit the payload
    double tPayload = payloadSymbNb * tSym;
 
    NS_LOG_DEBUG("Time computation: num = " << num << ", den = " << den << ", payloadSymbNb = "
                                            << payloadSymbNb << ", tSym = " << tSym);
    NS_LOG_DEBUG("tPreamble = " << tPreamble);
    NS_LOG_DEBUG("tPayload = " << tPayload);
    NS_LOG_DEBUG("Total time = " << tPreamble + tPayload);
 
    // Compute and return the total packet on-air time
    return Seconds(tPreamble + tPayload);
}
 
void
LorawanMac::SetSfForDataRate(std::vector<uint8_t> sfForDataRate)
{
    m_sfForDataRate = sfForDataRate;
}
 
void
LorawanMac::SetBandwidthForDataRate(std::vector<double> bandwidthForDataRate)
{
    m_bandwidthForDataRate = bandwidthForDataRate;
}
 
void
LorawanMac::SetMaxAppPayloadForDataRate(std::vector<uint32_t> maxAppPayloadForDataRate)
{
    m_maxAppPayloadForDataRate = maxAppPayloadForDataRate;
}
 
void
LorawanMac::SetTxDbmForTxPower(std::vector<double> txDbmForTxPower)
{
    m_txDbmForTxPower = txDbmForTxPower;
}
 
void
LorawanMac::SetNPreambleSymbols(int nPreambleSymbols)
{
    m_nPreambleSymbols = nPreambleSymbols;
}
 
int
LorawanMac::GetNPreambleSymbols(void)
{
    return m_nPreambleSymbols;
}
 
void
LorawanMac::setRegenerative(bool isRegenerative)
{
    NS_LOG_FUNCTION(this << isRegenerative);
    m_isRegenerative = isRegenerative;
}
 
void
LorawanMac::SetReplyDataRateMatrix(ReplyDataRateMatrix replyDataRateMatrix)
{
    m_replyDataRateMatrix = replyDataRateMatrix;
}
} // namespace ns3