satellite-ncc.cc

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2013 Magister Solutions Ltd
 * Copyright (c) 2018 CNES
 *
 * 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: Sami Rantanen <sami.rantanen@magister.fi>
 * Author: Mathias Ettinger <mettinger@toulouse.viveris.fr>
 */
 
#include "satellite-ncc.h"
 
#include "satellite-control-message.h"
#include "satellite-lower-layer-service.h"
#include "satellite-superframe-sequence.h"
 
#include "ns3/address.h"
#include "ns3/log.h"
#include "ns3/packet.h"
 
#include <map>
#include <tuple>
#include <utility>
 
NS_LOG_COMPONENT_DEFINE("SatNcc");
 
namespace ns3
{
 
NS_OBJECT_ENSURE_REGISTERED(SatNcc);
 
TypeId
SatNcc::GetTypeId(void)
{
    static TypeId tid =
        TypeId("ns3::SatNcc")
            .SetParent<Object>()
            .AddConstructor<SatNcc>()
            //
            // Trace sources
            //
            .AddTraceSource("NccRx",
                            "Trace source indicating a CR has received by NCC",
                            MakeTraceSourceAccessor(&SatNcc::m_nccRxTrace),
                            "ns3::Packet::TracedCallback")
            .AddTraceSource("NccTx",
                            "Trace source indicating a TBTP has sent by NCC",
                            MakeTraceSourceAccessor(&SatNcc::m_nccTxTrace),
                            "ns3::Packet::TracedCallback")
            .AddAttribute("HandoverDelay",
                          "Delay between handover acceptance and effective information transfer",
                          TimeValue(Seconds(0.0)),
                          MakeTimeAccessor(&SatNcc::m_utHandoverDelay),
                          MakeTimeChecker())
            .AddAttribute("UtTimeout",
                          "Timeout to logoff a UT, if logon procedure is used",
                          TimeValue(Seconds(10)),
                          MakeTimeAccessor(&SatNcc::m_utTimeout),
                          MakeTimeChecker());
    return tid;
}
 
SatNcc::SatNcc()
    : m_utHandoverDelay(Seconds(0.0)),
      m_utTimeout(Seconds(10)),
      m_useLogon(false),
      m_useLora(false)
{
    NS_LOG_FUNCTION(this);
}
 
SatNcc::~SatNcc()
{
    NS_LOG_FUNCTION(this);
}
 
void
SatNcc::DoDispose()
{
    NS_LOG_FUNCTION(this);
 
    m_updateRoutingCallback.Nullify();
    m_isLowRandomAccessLoad.clear();
 
    Object::DoDispose();
}
 
void
SatNcc::UtCnoUpdated(uint32_t satId,
                     uint32_t beamId,
                     Address sourceMac,
                     Address /*gwId*/,
                     double cno,
                     bool isSatelliteMac)
{
    NS_LOG_FUNCTION(this << satId << beamId << sourceMac << cno);
 
    if (isSatelliteMac)
    {
        m_beamSchedulers[std::make_pair(satId, beamId)]->UpdateSatelliteCno(sourceMac, cno);
    }
    else
    {
        m_beamSchedulers[std::make_pair(satId, beamId)]->UpdateUtCno(sourceMac, cno);
    }
}
 
void
SatNcc::DoRandomAccessDynamicLoadControl(uint32_t satId,
                                         uint32_t beamId,
                                         uint32_t carrierId,
                                         uint8_t allocationChannelId,
                                         double averageNormalizedOfferedLoad)
{
    NS_LOG_FUNCTION(this << satId << beamId << carrierId << (uint32_t)allocationChannelId
                         << averageNormalizedOfferedLoad);
 
    bool isLowRandomAccessLoad = true;
    std::map<std::tuple<uint32_t, uint32_t, uint8_t>, bool>::iterator findResult;
    std::pair<std::map<std::tuple<uint32_t, uint32_t, uint8_t>, bool>::iterator, bool> insertResult;

    findResult = m_isLowRandomAccessLoad.find(std::make_tuple(satId, beamId, allocationChannelId));
 
    if (findResult == m_isLowRandomAccessLoad.end())
    {
        insertResult = m_isLowRandomAccessLoad.insert(
            std::make_pair(std::make_tuple(satId, beamId, allocationChannelId),
                           isLowRandomAccessLoad));
 
        if (!insertResult.second)
        {
            NS_FATAL_ERROR("SatNcc::DoRandomAccessDynamicLoadControl - Insert failed");
        }
        else
        {
            isLowRandomAccessLoad = insertResult.second;
        }
    }
    else
    {
        isLowRandomAccessLoad = findResult->second;
    }
 
    NS_LOG_INFO("Beam: " << beamId << ", carrier ID: " << carrierId
                         << ", AC: " << (uint32_t)allocationChannelId
                         << " - Measuring the average normalized offered random access load: "
                         << averageNormalizedOfferedLoad);
 
    std::map<uint8_t, double>::iterator itThreshold =
        m_randomAccessAverageNormalizedOfferedLoadThreshold.find(allocationChannelId);
 
    if (itThreshold == m_randomAccessAverageNormalizedOfferedLoadThreshold.end())
    {
        NS_FATAL_ERROR("SatNcc::DoRandomAccessDynamicLoadControl - Average normalized offered load "
                       "threshold not set for beam: "
                       << beamId << ", carrier: " << carrierId
                       << ", allocation channel: " << (uint32_t)allocationChannelId);
    }

    if (isLowRandomAccessLoad)
    {
        NS_LOG_INFO("Beam: " << beamId << ", carrier ID: " << carrierId
                             << " - Currently low load in effect for allocation channel: "
                             << (uint32_t)allocationChannelId);
        if (averageNormalizedOfferedLoad >= itThreshold->second)
        {
            std::map<uint8_t, uint16_t>::iterator it;
 
            it = m_highLoadBackOffProbability.find(allocationChannelId);
 
            if (it == m_highLoadBackOffProbability.end())
            {
                NS_FATAL_ERROR("SatNcc::DoRandomAccessDynamicLoadControl - High load backoff "
                               "probability not set for allocation channel: "
                               << (uint32_t)allocationChannelId);
            }
 
            uint16_t probability = it->second;
 
            it = m_highLoadBackOffTime.find(allocationChannelId);
 
            if (it == m_highLoadBackOffTime.end())
            {
                NS_FATAL_ERROR("SatNcc::DoRandomAccessDynamicLoadControl - High load backoff time "
                               "not set for allocation channel: "
                               << (uint32_t)allocationChannelId);
            }
 
            uint16_t time = it->second;

            CreateRandomAccessLoadControlMessage(probability,
                                                 time,
                                                 satId,
                                                 beamId,
                                                 allocationChannelId);
 
            NS_LOG_INFO("Beam: " << beamId << ", carrier ID: " << carrierId
                                 << ", AC: " << (uint32_t)allocationChannelId
                                 << " - Switching to HIGH LOAD back off parameterization");

            m_isLowRandomAccessLoad.at(std::make_tuple(satId, beamId, allocationChannelId)) = false;
        }
    }
    else
    {
        NS_LOG_INFO("Beam: " << beamId << ", carrier ID: " << carrierId
                             << " - Currently high load in effect for allocation channel: "
                             << (uint32_t)allocationChannelId);

        if (averageNormalizedOfferedLoad < itThreshold->second)
        {
            std::map<uint8_t, uint16_t>::iterator it;
 
            it = m_lowLoadBackOffProbability.find(allocationChannelId);
 
            if (it == m_lowLoadBackOffProbability.end())
            {
                NS_FATAL_ERROR("SatNcc::DoRandomAccessDynamicLoadControl - Low load backoff "
                               "probability not set for allocation channel: "
                               << (uint32_t)allocationChannelId);
            }
 
            uint16_t probability = it->second;
 
            it = m_lowLoadBackOffTime.find(allocationChannelId);
 
            if (it == m_lowLoadBackOffTime.end())
            {
                NS_FATAL_ERROR("SatNcc::DoRandomAccessDynamicLoadControl - Low load backoff time "
                               "not set for allocation channel: "
                               << (uint32_t)allocationChannelId);
            }
 
            uint16_t time = it->second;

            CreateRandomAccessLoadControlMessage(probability,
                                                 time,
                                                 satId,
                                                 beamId,
                                                 allocationChannelId);
 
            NS_LOG_INFO("Beam: " << beamId << ", carrier ID: " << carrierId
                                 << ", AC: " << (uint32_t)allocationChannelId
                                 << " - Switching to LOW LOAD back off parameterization");

            m_isLowRandomAccessLoad.at(std::make_tuple(satId, beamId, allocationChannelId)) = true;
        }
    }
}
 
void
SatNcc::CreateRandomAccessLoadControlMessage(uint16_t backoffProbability,
                                             uint16_t backoffTime,
                                             uint32_t satId,
                                             uint32_t beamId,
                                             uint8_t allocationChannelId)
{
    NS_LOG_FUNCTION(this);
 
    Ptr<SatRaMessage> raMsg = CreateObject<SatRaMessage>();
    std::map<std::pair<uint32_t, uint32_t>, Ptr<SatBeamScheduler>>::iterator iterator =
        m_beamSchedulers.find(std::make_pair(satId, beamId));
 
    if (iterator == m_beamSchedulers.end())
    {
        NS_FATAL_ERROR("SatNcc::SendRaControlMessage - Beam scheduler not found");
    }

    raMsg->SetAllocationChannelId(allocationChannelId);

    raMsg->SetBackoffProbability(backoffProbability);
    raMsg->SetBackoffTime(backoffTime);
 
    NS_LOG_INFO("Sending random access control message for AC: "
                << (uint32_t)allocationChannelId << ", backoff probability: " << backoffProbability
                << ", backoff time: " << backoffTime);
 
    iterator->second->Send(raMsg);
}
 
void
SatNcc::UtCrReceived(uint32_t satId, uint32_t beamId, Address utId, Ptr<SatCrMessage> crMsg)
{
    NS_LOG_FUNCTION(this << satId << beamId << utId << crMsg);
 
    m_beamSchedulers[std::make_pair(satId, beamId)]->UtCrReceived(utId, crMsg);
}
 
void
SatNcc::AddBeam(uint32_t satId,
                uint32_t beamId,
                Ptr<SatNetDevice> gwNetDevice,
                Ptr<SatOrbiterNetDevice> orbiterNetDevice,
                SatNcc::SendCallback cb,
                SatNcc::SendTbtpCallback tbtpCb,
                Ptr<SatSuperframeSeq> seq,
                uint32_t maxFrameSize,
                Address satAddress,
                Address gwAddress)
{
    NS_LOG_FUNCTION(this << satId << beamId << gwNetDevice << orbiterNetDevice << &cb << &tbtpCb
                         << seq << maxFrameSize << satAddress << gwAddress);
 
    Ptr<SatBeamScheduler> scheduler;
    std::map<std::pair<uint32_t, uint32_t>, Ptr<SatBeamScheduler>>::iterator iterator =
        m_beamSchedulers.find(std::make_pair(satId, beamId));
 
    if (iterator != m_beamSchedulers.end())
    {
        NS_FATAL_ERROR("Beam tried to add, already added.");
    }
 
    scheduler = CreateObject<SatBeamScheduler>();
    scheduler->Initialize(satId,
                          beamId,
                          gwNetDevice,
                          orbiterNetDevice,
                          cb,
                          seq,
                          maxFrameSize,
                          satAddress,
                          gwAddress);
 
    scheduler->SetSendTbtpCallback(tbtpCb);
 
    scheduler->SetUseLora(m_useLora);
 
    m_beamSchedulers.insert(std::make_pair(std::make_pair(satId, beamId), scheduler));
}
 
void
SatNcc::AddUt(Ptr<SatLowerLayerServiceConf> llsConf,
              Address utId,
              uint32_t satId,
              uint32_t beamId,
              Callback<void, uint32_t> setRaChannelCallback,
              bool verifyExisting)
{
    NS_LOG_FUNCTION(this << utId << beamId);
 
    std::map<std::pair<uint32_t, uint32_t>, Ptr<SatBeamScheduler>>::iterator iterator =
        m_beamSchedulers.find(std::make_pair(satId, beamId));
 
    if (iterator == m_beamSchedulers.end())
    {
        NS_FATAL_ERROR("Beam where tried to add, not found.");
    }
 
    if (!verifyExisting || !(m_beamSchedulers[std::make_pair(satId, beamId)]->HasUt(utId)))
    {
        setRaChannelCallback(m_beamSchedulers[std::make_pair(satId, beamId)]->AddUt(utId, llsConf));
    }
}
 
void
SatNcc::RemoveUt(Address utId, uint32_t satId, uint32_t beamId)
{
    NS_LOG_FUNCTION(this << utId << beamId);
 
    if (m_beamSchedulers[std::make_pair(satId, beamId)]->HasUt(utId))
    {
        m_beamSchedulers[std::make_pair(satId, beamId)]->RemoveUt(utId);
    }
}
 
void
SatNcc::SetRandomAccessLowLoadBackoffProbability(uint8_t allocationChannelId,
                                                 uint16_t lowLoadBackOffProbability)
{
    NS_LOG_FUNCTION(this << (uint32_t)allocationChannelId << lowLoadBackOffProbability);
 
    NS_LOG_INFO("AC: " << (uint32_t)allocationChannelId
                       << ", low load backoff probability: " << lowLoadBackOffProbability);
    m_lowLoadBackOffProbability[allocationChannelId] = lowLoadBackOffProbability;
}
 
void
SatNcc::SetRandomAccessHighLoadBackoffProbability(uint8_t allocationChannelId,
                                                  uint16_t highLoadBackOffProbability)
{
    NS_LOG_FUNCTION(this << (uint32_t)allocationChannelId << highLoadBackOffProbability);
 
    NS_LOG_INFO("AC: " << (uint32_t)allocationChannelId
                       << ", high load backoff probability: " << highLoadBackOffProbability);
    m_highLoadBackOffProbability[allocationChannelId] = highLoadBackOffProbability;
}
 
void
SatNcc::SetRandomAccessLowLoadBackoffTime(uint8_t allocationChannelId, uint16_t lowLoadBackOffTime)
{
    NS_LOG_FUNCTION(this << (uint32_t)allocationChannelId << lowLoadBackOffTime);
 
    NS_LOG_INFO("AC: " << (uint32_t)allocationChannelId
                       << ", low load backoff time: " << lowLoadBackOffTime);
    m_lowLoadBackOffTime[allocationChannelId] = lowLoadBackOffTime;
}
 
void
SatNcc::SetRandomAccessHighLoadBackoffTime(uint8_t allocationChannelId,
                                           uint16_t highLoadBackOffTime)
{
    NS_LOG_FUNCTION(this << (uint32_t)allocationChannelId << highLoadBackOffTime);
 
    NS_LOG_INFO("AC: " << (uint32_t)allocationChannelId
                       << ", high load backoff time: " << highLoadBackOffTime);
    m_highLoadBackOffTime[allocationChannelId] = highLoadBackOffTime;
}
 
void
SatNcc::SetRandomAccessAverageNormalizedOfferedLoadThreshold(uint8_t allocationChannelId,
                                                             double threshold)
{
    NS_LOG_FUNCTION(this << (uint32_t)allocationChannelId << threshold);
 
    NS_LOG_INFO("AC: " << (uint32_t)allocationChannelId
                       << ", average normalized offered load threshold: " << threshold);
    m_randomAccessAverageNormalizedOfferedLoadThreshold[allocationChannelId] = threshold;
}
 
Ptr<SatBeamScheduler>
SatNcc::GetBeamScheduler(uint32_t satId, uint32_t beamId) const
{
    NS_LOG_FUNCTION(this << satId << beamId);
 
    std::map<std::pair<uint32_t, uint32_t>, Ptr<SatBeamScheduler>>::const_iterator it =
        m_beamSchedulers.find(std::make_pair(satId, beamId));
 
    if (it == m_beamSchedulers.end())
    {
        return 0;
    }
    else
    {
        return it->second;
    }
}
 
void
SatNcc::DoMoveUtBetweenBeams(Address utId,
                             uint32_t srcSatId,
                             uint32_t srcBeamId,
                             uint32_t destSatId,
                             uint32_t destBeamId)
{
    NS_LOG_FUNCTION(this << utId << srcSatId << srcBeamId << destSatId << destBeamId);
 
    Ptr<SatBeamScheduler> srcScheduler = GetBeamScheduler(srcSatId, srcBeamId);
    Ptr<SatBeamScheduler> destScheduler = GetBeamScheduler(destSatId, destBeamId);
 
    if (!srcScheduler)
    {
        NS_FATAL_ERROR("Source beam not configured");
    }
 
    if (!destScheduler)
    {
        NS_FATAL_ERROR("Destination beam not configured");
    }
 
    srcScheduler->TransferUtToBeam(utId, destScheduler);
    m_updateRoutingCallback(utId, srcScheduler->GetGwAddress(), destScheduler->GetGwAddress());
}
 
void
SatNcc::MoveUtBetweenBeams(Address utId,
                           uint32_t srcSatId,
                           uint32_t srcBeamId,
                           uint32_t destSatId,
                           uint32_t destBeamId)
{
    NS_LOG_FUNCTION(this << utId << srcSatId << srcBeamId << destSatId << destBeamId);
 
    Ptr<SatBeamScheduler> scheduler = GetBeamScheduler(srcSatId, srcBeamId);
    Ptr<SatBeamScheduler> destination = GetBeamScheduler(destSatId, destBeamId);
 
    if (!scheduler)
    {
        NS_FATAL_ERROR("Source beam does not exist!");
    }
 
    if (!destination)
    {
        NS_LOG_WARN("Destination beam does not exist, cancel handover");
 
        Ptr<SatTimuMessage> timuMsg = scheduler->CreateTimu();
        scheduler->SendTo(timuMsg, utId);
    }
    else if (scheduler->HasUt(utId) && !destination->HasUt(utId))
    {
        NS_LOG_INFO("Performing handover!");
 
        Ptr<SatTimuMessage> timuMsg = destination->CreateTimu();
        scheduler->SendTo(timuMsg, utId);
 
        Simulator::Schedule(m_utHandoverDelay,
                            &SatNcc::DoMoveUtBetweenBeams,
                            this,
                            utId,
                            srcSatId,
                            srcBeamId,
                            destSatId,
                            destBeamId);
    }
    else if (!scheduler->HasUt(utId) && destination->HasUt(utId))
    {
        NS_LOG_INFO("Handover already performed, sending back TIM-U just in case!");
 
        Ptr<SatTimuMessage> timuMsg = destination->CreateTimu();
        scheduler->SendTo(timuMsg, utId);
    }
    else
    {
        NS_FATAL_ERROR("Inconsistent handover state: UT is neither in source nor destination beam; "
                       "or in both");
    }
}
 
void
SatNcc::SetUpdateRoutingCallback(SatNcc::UpdateRoutingCallback cb)
{
    NS_LOG_FUNCTION(this << &cb);
 
    m_updateRoutingCallback = cb;
}
 
void
SatNcc::ReserveLogonChannel(uint32_t logonChannelId)
{
    NS_LOG_FUNCTION(this << logonChannelId);
 
    for (auto& beamScheduler : m_beamSchedulers)
    {
        beamScheduler.second->ReserveLogonChannel(logonChannelId);
    }
}
 
void
SatNcc::ReceiveControlBurst(Address utId, uint32_t satId, uint32_t beamId)
{
    NS_LOG_FUNCTION(this << utId << beamId);
 
    std::tuple<Address, uint32_t, uint32_t> id = std::make_tuple(utId, satId, beamId);
 
    if ((m_lastControlBurstReception.find(id) == m_lastControlBurstReception.end()) && m_useLogon)
    {
        Simulator::Schedule(m_utTimeout, &SatNcc::CheckTimeout, this, utId, satId, beamId);
    }
    m_lastControlBurstReception[id] = Simulator::Now();
}
 
void
SatNcc::SetUseLogon(bool useLogon)
{
    NS_LOG_FUNCTION(this << useLogon);
 
    m_useLogon = useLogon;
}
 
void
SatNcc::SetUseLora(bool useLora)
{
    NS_LOG_FUNCTION(this << useLora);
 
    m_useLora = useLora;
 
    for (std::pair<std::pair<uint32_t, uint32_t>, Ptr<SatBeamScheduler>> beamScheduler :
         m_beamSchedulers)
    {
        beamScheduler.second->SetUseLora(m_useLora);
    }
}
 
void
SatNcc::CheckTimeout(Address utId, uint32_t satId, uint32_t beamId)
{
    NS_LOG_FUNCTION(this << utId);
 
    std::tuple<Address, uint32_t, uint32_t> id = std::make_tuple(utId, satId, beamId);
    NS_ASSERT_MSG(m_lastControlBurstReception.find(id) != m_lastControlBurstReception.end(),
                  "UT address should be in map");
 
    Time lastReceptionDate = m_lastControlBurstReception[id];
    if (Simulator::Now() >= lastReceptionDate + m_utTimeout)
    {
        m_lastControlBurstReception.erase(id);
        RemoveUt(utId, satId, beamId);
    }
    else
    {
        Simulator::Schedule(lastReceptionDate + m_utTimeout - Simulator::Now(),
                            &SatNcc::CheckTimeout,
                            this,
                            utId,
                            satId,
                            beamId);
    }
}
 
} // namespace ns3