class-a-end-device-lorawan-mac.h

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/*
 * Copyright (c) 2017 University of Padova
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Davide Magrin <magrinda@dei.unipd.it>
 *         Martina Capuzzo <capuzzom@dei.unipd.it>
 *
 * Modified by: Peggy Anderson <peggy.anderson@usask.ca>
 */
 
#ifndef CLASS_A_END_DEVICE_LORAWAN_MAC_H
#define CLASS_A_END_DEVICE_LORAWAN_MAC_H
 
#include "end-device-lorawan-mac.h"
 
namespace ns3
{
namespace lorawan
{
 
/**
 * @ingroup lorawan
 *
 * Class representing the MAC layer of a Class A LoRaWAN device.
 */
class ClassAEndDeviceLorawanMac : public EndDeviceLorawanMac
{
  public:
    /**
     *  Register this type.
     *  @return The object TypeId.
     */
    static TypeId GetTypeId();
 
    ClassAEndDeviceLorawanMac();           //!< Default constructor
    ~ClassAEndDeviceLorawanMac() override; //!< Destructor
 
    /**
     * Get the data rate that will be used in the first receive window.
     *
     * @return The data rate.
     */
    uint8_t GetFirstReceiveWindowDataRate();
 
    /**
     * Set the data rate to be used in the second receive window.
     *
     * @param dataRate The data rate.
     */
    void SetSecondReceiveWindowDataRate(uint8_t dataRate);
 
    /**
     * Get the data rate that will be used in the second receive window.
     *
     * @return The data rate.
     */
    uint8_t GetSecondReceiveWindowDataRate() const;
 
    /**
     * Set the frequency that will be used for the second receive window.
     *
     * @param frequencyHz The Frequency.
     */
    void SetSecondReceiveWindowFrequency(uint32_t frequencyHz);
 
    /**
     * Get the frequency that is used for the second receive window.
     *
     * @return The frequency, in Hz.
     */
    uint32_t GetSecondReceiveWindowFrequency() const;
 
  private:
    /**
     * Set of possible outcomes of a reception window
     */
    enum RxOutcome
    {
        ACK,  //!< Correctly received a network acknowledgement
        RECV, //!< Correctly received a downlink packet (no ACK)
        FAIL, //!< Reception initiated but failed
        NONE  //!< Reception window timed out
    };
 
    Time GetNextClassTransmissionDelay() const override;
    void SendToPhy(Ptr<Packet> packet) override;
    void TxFinished(Ptr<const Packet> packet) override;
 
    /**
     * Perform operations needed to open the first receive window.
     */
    void OpenFirstReceiveWindow();
 
    /**
     * Perform operations needed to open the second receive window.
     */
    void OpenSecondReceiveWindow();
 
    /**
     * Perform operations needed to close the first receive window.
     */
    void CloseFirstReceiveWindow();
 
    /**
     * Perform operations needed to close the second receive window.
     */
    void CloseSecondReceiveWindow();
 
    /**
     * Decide whether we can retransmit based on reception outcome.
     *
     * @param outcome Outcome of the reception.
     */
    void ManageRetransmissions(RxOutcome outcome);
 
    void Receive(Ptr<const Packet> packet) override;
    void FailedReception(Ptr<const Packet> packet) override;
    void OnRxParamSetupReq(uint8_t rx1DrOffset, uint8_t rx2DataRate, double frequencyHz) override;
 
    EventId m_secondReceiveWindow; //!< The event of the second receive window opening, used
                                   //!< to cancel the second window in case the first one is
                                   //!< successful.
 
    // Reception window parameters
 
    Time m_receiveDelay1; //!< The interval between when a packet is done sending and when the first
                          //!< receive window is opened.
    uint32_t m_firstReceiveWindowFrequencyHz; //!< The frequency [Hz] to listen on for the first
                                              //!< receive window. This value is set dynamically to
                                              //!< the last uplink transmission frequency.
    uint8_t m_rx1DrOffset;                    //!< The RX1DROffset parameter value.
 
    Time m_receiveDelay2; //!< The interval between when a packet is done sending and when the
                          //!< second receive window is opened.
    uint32_t m_secondReceiveWindowFrequencyHz; //!< The frequency [Hz] to listen on for the second
                                               //!< receive window.
    uint8_t m_secondReceiveWindowDataRate;     //!< The data rate to listen for during the second
                                               //!< downlink transmission.
 
    // Rescheduling purposes
 
    bool m_busy; //!< Whether the MAC layer is currently busy with in the LoRaWAN Class A process of
                 //!< transmitting an uplink packet and then opening two reception windows.
};
 
} /* namespace lorawan */
} /* namespace ns3 */
 
#endif /* CLASS_A_END_DEVICE_LORAWAN_MAC_H */