lora-logical-channel-helper.cc

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/* -*- 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 "lora-logical-channel-helper.h"
 
#include "ns3/log.h"
#include "ns3/simulator.h"
 
#include <algorithm>
#include <iterator>
#include <list>
#include <vector>
 
namespace ns3
{
 
NS_LOG_COMPONENT_DEFINE("LoraLogicalChannelHelper");
 
NS_OBJECT_ENSURE_REGISTERED(LoraLogicalChannelHelper);
 
TypeId
LoraLogicalChannelHelper::GetTypeId(void)
{
    static TypeId tid = TypeId("ns3::LoraLogicalChannelHelper").SetParent<Object>();
    return tid;
}
 
LoraLogicalChannelHelper::LoraLogicalChannelHelper()
    : m_nextAggregatedTransmissionTime(Seconds(0)),
      m_aggregatedDutyCycle(1)
{
    NS_LOG_FUNCTION(this);
}
 
LoraLogicalChannelHelper::~LoraLogicalChannelHelper()
{
    NS_LOG_FUNCTION(this);
}
 
std::vector<Ptr<LoraLogicalChannel>>
LoraLogicalChannelHelper::GetChannelList(void)
{
    NS_LOG_FUNCTION(this);
 
    // Make a copy of the channel vector
    std::vector<Ptr<LoraLogicalChannel>> vector;
    vector.reserve(m_channelList.size());
    std::copy(m_channelList.begin(), m_channelList.end(), std::back_inserter(vector));
 
    return vector;
}
 
std::vector<Ptr<LoraLogicalChannel>>
LoraLogicalChannelHelper::GetEnabledChannelList(void)
{
    NS_LOG_FUNCTION(this);
 
    // Make a copy of the channel vector
    std::vector<Ptr<LoraLogicalChannel>> vector;
    vector.reserve(m_channelList.size());
    std::copy(m_channelList.begin(),
              m_channelList.end(),
              std::back_inserter(vector)); // Working on a copy
 
    std::vector<Ptr<LoraLogicalChannel>> channels;
    std::vector<Ptr<LoraLogicalChannel>>::iterator it;
    for (it = vector.begin(); it != vector.end(); it++)
    {
        if ((*it)->IsEnabledForUplink())
        {
            channels.push_back(*it);
        }
    }
 
    return channels;
}
 
Ptr<LoraSubBand>
LoraLogicalChannelHelper::GetLoraSubBandFromChannel(Ptr<LoraLogicalChannel> channel)
{
    return GetLoraSubBandFromFrequency(channel->GetFrequency());
}
 
Ptr<LoraSubBand>
LoraLogicalChannelHelper::GetLoraSubBandFromFrequency(double frequency)
{
    NS_LOG_FUNCTION(this << frequency);
    // Get the LoraSubBand this frequency belongs to
    std::list<Ptr<LoraSubBand>>::iterator it;
    for (it = m_subBandList.begin(); it != m_subBandList.end(); it++)
    {
        if ((*it)->BelongsToLoraSubBand(frequency))
        {
            return *it;
        }
    }
 
    NS_LOG_ERROR("Requested frequency: " << frequency);
    NS_ABORT_MSG("Warning: frequency is outside any known LoraSubBand.");
 
    return 0; // If no LoraSubBand is found, return 0
}
 
void
LoraLogicalChannelHelper::AddChannel(double frequency)
{
    NS_LOG_FUNCTION(this << frequency);
 
    // Create the new channel and increment the counter
    Ptr<LoraLogicalChannel> channel = CreateObject<LoraLogicalChannel>(frequency);
 
    // Add it to the list
    m_channelList.push_back(channel);
 
    NS_LOG_DEBUG("Added a channel. Current number of channels in list is " << m_channelList.size());
}
 
void
LoraLogicalChannelHelper::AddChannel(Ptr<LoraLogicalChannel> logicalChannel)
{
    NS_LOG_FUNCTION(this << logicalChannel);
 
    // Add it to the list
    m_channelList.push_back(logicalChannel);
}
 
void
LoraLogicalChannelHelper::SetChannel(uint8_t chIndex, Ptr<LoraLogicalChannel> logicalChannel)
 
{
    NS_LOG_FUNCTION(this << chIndex << logicalChannel);
 
    m_channelList.at(chIndex) = logicalChannel;
}
 
void
LoraLogicalChannelHelper::AddLoraSubBand(double firstFrequency,
                                         double lastFrequency,
                                         double dutyCycle,
                                         double maxTxPowerDbm)
{
    NS_LOG_FUNCTION(this << firstFrequency << lastFrequency);
 
    Ptr<LoraSubBand> subBand =
        CreateObject<LoraSubBand>(firstFrequency, lastFrequency, dutyCycle, maxTxPowerDbm);
 
    m_subBandList.push_back(subBand);
}
 
void
LoraLogicalChannelHelper::AddLoraSubBand(Ptr<LoraSubBand> subBand)
{
    NS_LOG_FUNCTION(this << subBand);
 
    m_subBandList.push_back(subBand);
}
 
void
LoraLogicalChannelHelper::RemoveChannel(Ptr<LoraLogicalChannel> logicalChannel)
{
    // Search and remove the channel from the list
    std::vector<Ptr<LoraLogicalChannel>>::iterator it;
    for (it = m_channelList.begin(); it != m_channelList.end(); it++)
    {
        Ptr<LoraLogicalChannel> currentChannel = *it;
        if (currentChannel == logicalChannel)
        {
            m_channelList.erase(it);
            return;
        }
    }
}
 
Time
LoraLogicalChannelHelper::GetAggregatedWaitingTime(void)
{
    // Aggregate waiting time
    Time aggregatedWaitingTime = m_nextAggregatedTransmissionTime - Simulator::Now();
 
    // Handle case in which waiting time is negative
    aggregatedWaitingTime = Seconds(std::max(aggregatedWaitingTime.GetSeconds(), double(0)));
 
    NS_LOG_DEBUG("Aggregated waiting time: " << aggregatedWaitingTime.GetSeconds());
 
    return aggregatedWaitingTime;
}
 
Time
LoraLogicalChannelHelper::GetWaitingTime(Ptr<LoraLogicalChannel> channel)
{
    NS_LOG_FUNCTION(this << channel);
 
    // LoraSubBand waiting time
    Time subBandWaitingTime =
        GetLoraSubBandFromChannel(channel)->GetNextTransmissionTime() - Simulator::Now();
 
    // Handle case in which waiting time is negative
    subBandWaitingTime = Seconds(std::max(subBandWaitingTime.GetSeconds(), double(0)));
 
    NS_LOG_DEBUG("Waiting time: " << subBandWaitingTime.GetSeconds());
 
    return subBandWaitingTime;
}
 
void
LoraLogicalChannelHelper::AddEvent(Time duration, Ptr<LoraLogicalChannel> channel)
{
    NS_LOG_FUNCTION(this << duration << channel);
 
    Ptr<LoraSubBand> subBand = GetLoraSubBandFromChannel(channel);
 
    double dutyCycle = subBand->GetDutyCycle();
    double timeOnAir = duration.GetSeconds();
 
    // Computation of necessary waiting time on this sub-band
    subBand->SetNextTransmissionTime(Simulator::Now() + Seconds(timeOnAir / dutyCycle - timeOnAir));
 
    // Computation of necessary aggregate waiting time
    m_nextAggregatedTransmissionTime =
        Simulator::Now() + Seconds(timeOnAir / m_aggregatedDutyCycle - timeOnAir);
 
    NS_LOG_DEBUG("Time on air: " << timeOnAir);
    NS_LOG_DEBUG("m_aggregatedDutyCycle: " << m_aggregatedDutyCycle);
    NS_LOG_DEBUG("Current time: " << Simulator::Now().GetSeconds());
    NS_LOG_DEBUG("Next transmission on this sub-band allowed at time: "
                 << (subBand->GetNextTransmissionTime()).GetSeconds());
    NS_LOG_DEBUG("Next aggregated transmission allowed at time "
                 << m_nextAggregatedTransmissionTime.GetSeconds());
}
 
double
LoraLogicalChannelHelper::GetTxPowerForChannel(Ptr<LoraLogicalChannel> logicalChannel)
{
    NS_LOG_FUNCTION_NOARGS();
 
    // Get the maxTxPowerDbm from the LoraSubBand this channel is in
    std::list<Ptr<LoraSubBand>>::iterator it;
    for (it = m_subBandList.begin(); it != m_subBandList.end(); it++)
    {
        // Check whether this channel is in this LoraSubBand
        if ((*it)->BelongsToLoraSubBand(logicalChannel->GetFrequency()))
        {
            return (*it)->GetMaxTxPowerDbm();
        }
    }
    NS_ABORT_MSG("Logical channel doesn't belong to a known LoraSubBand");
 
    return 0;
}
 
void
LoraLogicalChannelHelper::DisableChannel(int index)
{
    NS_LOG_FUNCTION(this << index);
 
    m_channelList.at(index)->DisableForUplink();
}
} // namespace ns3