Satellite_PropagationModel.c

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/************************************************************************************
* Copyright (C) 2021                                                                *
* TETCOS, Bangalore. India                                                          *
*                                                                                   *
* Tetcos owns the intellectual property rights in the Product and its content.      *
* The copying, redistribution, reselling or publication of any or all of the        *
* Product or its content without express prior written consent of Tetcos is         *
* prohibited. Ownership and / or any other right relating to the software and all   *
* intellectual property rights therein shall remain at all times with Tetcos.       *
*                                                                                   *
* This source code is licensed per the NetSim license agreement.                    *
*                                                                                   *
* No portion of this source code may be used as the basis for a derivative work,    *
* or used, for any purpose other than its intended use per the NetSim license       *
* agreement.                                                                        *
*                                                                                   *
* This source code and the algorithms contained within it are confidential trade    *
* secrets of TETCOS and may not be used as the basis for any other software,        *
* hardware, product or service.                                                     *
*                                                                                   *
* Author:    Shashi Kant Suman                                                      *
*                                                                                   *
* ----------------------------------------------------------------------------------*/
#include "main.h"
#include "SATELLITE.h"
#include "Satellite_PHY.h"
#include "Satellite_MAC.h"
#include "Satellite_Frame.h"
 
#pragma region FUNCTIONPROTOTYPE
static void create_tx_info_for_ut(NETSIM_ID d, NETSIM_ID in,
                                  PTX_INFO info, LINKTYPE linkType);
static void create_tx_info_for_gw(NETSIM_ID d, NETSIM_ID in,
                                  PTX_INFO info, LINKTYPE linkType);
static void fill_propagation_from_link(NETSIM_ID d, NETSIM_ID in,
                                       PPROPAGATION prop);
#pragma endregion
 
#pragma region PROPAGATIONMODEL_INIT
void satellite_propgation_ut_init(NETSIM_ID d, NETSIM_ID in)
{
    ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(d, in);
    ptrSATELLITE_UT_MAC mac = SATELLITE_UTMAC_GET(d, in);
 
    TX_INFO txInfo;
    create_tx_info_for_ut(d, in, &txInfo, LINKTYPE_RETURN);
 
    PROPAGATION prop;
    fill_propagation_from_link(d, in, &prop);
 
    phy->txPropagationInfo = propagation_create_propagation_info(d, in,
                                                                 mac->satelliteId, mac->satelliteIf,
                                                                 NULL, &txInfo, &prop);
 
    create_tx_info_for_ut(d, in, &txInfo, LINKTYPE_FORWARD);
    phy->rxPropagationInfo = propagation_create_propagation_info(mac->satelliteId, mac->satelliteIf, 
                                                                 d, in,
                                                                 NULL, &txInfo, &prop);
}
 
void satellite_propgation_gw_init(NETSIM_ID d, NETSIM_ID in)
{
    ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(d, in);
    ptrSATELLITE_GW_MAC mac = SATELLITE_GWMAC_GET(d, in);
 
    TX_INFO txInfo;
    create_tx_info_for_gw(d, in, &txInfo, LINKTYPE_FORWARD);
 
    PROPAGATION prop;
    fill_propagation_from_link(d, in, &prop);
 
    phy->txPropagationInfo = propagation_create_propagation_info(d, in,
                                                                 mac->satelliteId, mac->satelliteIf,
                                                                 NULL, &txInfo, &prop);
 
    create_tx_info_for_gw(d, in, &txInfo, LINKTYPE_RETURN);
    phy->rxPropagationInfo = propagation_create_propagation_info(mac->satelliteId, mac->satelliteIf,
                                                                 d, in,
                                                                 NULL, &txInfo, &prop);
}
#pragma endregion
 
#pragma region PROPAGATIONMODEL_HELPER
static void create_tx_info_for_ut(NETSIM_ID d, NETSIM_ID in,
                                  PTX_INFO info, LINKTYPE linkType)
{
    memset(info, 0, sizeof * info);
    ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(d, in);
    ptrSATELLITE_UT_MAC mac = SATELLITE_UTMAC_GET(d, in);
 
    NETSIM_ID s = mac->satelliteId;
    NETSIM_ID sin = mac->satelliteIf;
    ptrSATELLITE_MAC smac = SATELLITE_MAC_GET(s, sin);
    ptrSATELLITE_PHY sphy = SATELLITE_PHY_GET(s, sin);
 
    if (linkType == LINKTYPE_FORWARD)
    {
        ptrSUPERFRAME sf = smac->forwardFLinkSuperFrame;
        info->dRxGain = phy->rxAntennaGain_db;
        info->dTxGain = sphy->txAntennaGain_db;
        info->dTxPower_dbm = sphy->txPower_dbm;
        info->dTxPower_mw = sphy->txPower_mw;
        info->dCentralFrequency = sf->centralFrequency_Hz / MHZ;
    }
    else if (linkType == LINKTYPE_RETURN)
    {
        ptrSUPERFRAME sf = smac->returnLinkSuperFrame;
        info->dTxGain = phy->txAntennaGain_db;
        info->dRxGain = sphy->rxAntennaGain_db;
        info->dTxPower_dbm = phy->txPower_dbm;
        info->dTxPower_mw = phy->txPower_mw;
        info->dCentralFrequency = sf->centralFrequency_Hz / MHZ;
    }
 
    info->d0 = 1;
    info->dTx_Rx_Distance = DEVICE_DISTANCE(d, s);
}
 
static void fill_propagation_from_link(NETSIM_ID d, NETSIM_ID in,
                                       PPROPAGATION prop)
{
    memset(prop, 0, sizeof * prop);
    NetSim_LINKS* link = DEVICE_PHYLAYER(d, in)->pstruNetSimLinks;
    memcpy(prop, link->puniMedProp.pstruWirelessLink.propagation, sizeof * prop);
    prop->pathlossVar.d0 = 1;
}
 
static void create_tx_info_for_gw(NETSIM_ID d, NETSIM_ID in,
                                  PTX_INFO info, LINKTYPE linkType)
{
    memset(info, 0, sizeof * info);
    ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(d, in);
    ptrSATELLITE_GW_MAC mac = SATELLITE_GWMAC_GET(d, in);
 
    NETSIM_ID s = mac->satelliteId;
    NETSIM_ID sin = mac->satelliteIf;
    ptrSATELLITE_MAC smac = SATELLITE_MAC_GET(s, sin);
    ptrSATELLITE_PHY sphy = SATELLITE_PHY_GET(s, sin);
 
    if (linkType == LINKTYPE_FORWARD)
    {
        ptrSUPERFRAME sf = smac->forwardFLinkSuperFrame;
        info->dTxGain = phy->txAntennaGain_db;
        info->dRxGain = sphy->rxAntennaGain_db;
        info->dTxPower_dbm = phy->txPower_dbm;
        info->dTxPower_mw = phy->txPower_mw;
        info->dCentralFrequency = sf->centralFrequency_Hz / MHZ;
    }
    else if (linkType == LINKTYPE_RETURN)
    {
        ptrSUPERFRAME sf = smac->returnLinkSuperFrame;
        info->dRxGain = phy->rxAntennaGain_db;
        info->dTxGain = sphy->txAntennaGain_db;
        info->dTxPower_dbm = sphy->txPower_dbm;
        info->dTxPower_mw = sphy->txPower_mw;
        info->dCentralFrequency = sf->centralFrequency_Hz / MHZ;
    }
 
    info->d0 = 1;
    info->dTx_Rx_Distance = DEVICE_DISTANCE(d, s);
}
#pragma endregion
 
#pragma region PROPAGATIONMODEL_CALCULATE
void satellite_propagation_ut_calculate_rxpower(NETSIM_ID d, NETSIM_ID in, double time)
{
    ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(d, in);
    _propagation_calculate_received_power(phy->txPropagationInfo, time);
    _propagation_calculate_received_power(phy->rxPropagationInfo, time);
}
 
void satellite_propagation_gw_calculate_rxpower(NETSIM_ID d, NETSIM_ID in, double time)
{
    ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(d, in);
    _propagation_calculate_received_power(phy->txPropagationInfo, time);
    _propagation_calculate_received_power(phy->rxPropagationInfo, time);
}
#pragma endregion
 
#pragma region SATELLITE_PACKET_ERROR
static double satellite_get_rx_power_dbm(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri)
{
    if (isUT(t, ti))
    {
        ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(t, ti);
        return _propagation_get_received_power_dbm(phy->txPropagationInfo, 0);
    }
    else if (isGW(t, ti))
    {
        ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(t, ti);
        return _propagation_get_received_power_dbm(phy->txPropagationInfo, 0);
    }
    else
    {
        if (isUT(r, ri))
        {
            ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(r, ri);
            return _propagation_get_received_power_dbm(phy->rxPropagationInfo, 0);
        }
        else if (isGW(r, ri))
        {
            ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(r, ri);
            return _propagation_get_received_power_dbm(phy->rxPropagationInfo, 0);
        }
    }
    return 0;
}
 
static double satellite_get_fading_loss_db(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri)
{
    if (isUT(t, ti))
    {
        ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(t, ti);
        return _propagation_calculate_fadingloss(phy->txPropagationInfo);
    }
    else if (isGW(t, ti))
    {
        ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(t, ti);
        return _propagation_calculate_fadingloss(phy->txPropagationInfo);
    }
    else
    {
        if (isUT(r, ri))
        {
            ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(r, ri);
            return _propagation_calculate_fadingloss(phy->rxPropagationInfo);
        }
        else if (isGW(r, ri))
        {
            ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(r, ri);
            return _propagation_calculate_fadingloss(phy->rxPropagationInfo);
        }
    }
    return 0;
}
 
#define BOLTZMAAN_CONSTANT  1.38064852e-23 // m2 kg s-2 K-1
static double satellite_calculate_noise(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri)
{
    double noise_w = 0;
    if (isUT(t, ti))
    {
        ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(t, ti);
        ptrSATELLITE_PHY sphy = SATELLITE_PHY_GET(r, ri);
        noise_w = BOLTZMAAN_CONSTANT * phy->tempeature_k * sphy->returnLinkSuperFrame->carrierConfig->allocatedBandwidth_Hz;
    }
    else if (isGW(t, ti))
    {
        ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(t, ti);
        ptrSATELLITE_PHY sphy = SATELLITE_PHY_GET(r, ri);
        noise_w = BOLTZMAAN_CONSTANT * phy->tempeature_k * sphy->forwardLinkSuperFrame->carrierConfig->allocatedBandwidth_Hz;
    }
    else
    {
        if (isUT(r, ri))
        {
            ptrSATELLITE_UT_PHY phy = SATELLITE_UTPHY_GET(r, ri);
            ptrSATELLITE_PHY sphy = SATELLITE_PHY_GET(t, ti);
            noise_w = BOLTZMAAN_CONSTANT * phy->tempeature_k * sphy->forwardLinkSuperFrame->carrierConfig->allocatedBandwidth_Hz;
        }
        else if (isGW(r, ri))
        {
            ptrSATELLITE_GW_PHY phy = SATELLITE_GWPHY_GET(r, ri);
            ptrSATELLITE_PHY sphy = SATELLITE_PHY_GET(t, ti);
            noise_w = BOLTZMAAN_CONSTANT * phy->tempeature_k * sphy->returnLinkSuperFrame->carrierConfig->allocatedBandwidth_Hz;
        }
    }
 
    return MW_TO_DBM(noise_w * 1000);
}
 
static double satellite_calculate_snr(double pdbm, double ndbm)
{
    return MW_TO_DBM(DBM_TO_MW(pdbm) / DBM_TO_MW(ndbm));
}
 
static ptrSUPERFRAME find_superframe(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri)
{
    if (isUT(t, ti))
    {
        ptrSATELLITE_PHY phy = SATELLITE_PHY_GET(r, ri);
        return phy->returnLinkSuperFrame;
    }
    else if (isGW(t, ti))
    {
        ptrSATELLITE_PHY phy = SATELLITE_PHY_GET(r, ri);
        return phy->forwardLinkSuperFrame;
    }
    else
    {
        if (isUT(r, ri))
        {
            ptrSATELLITE_PHY phy = SATELLITE_PHY_GET(t, ti);
            return phy->forwardLinkSuperFrame;
        }
        else if (isGW(r, ri))
        {
            ptrSATELLITE_PHY phy = SATELLITE_PHY_GET(t, ti);
            return phy->returnLinkSuperFrame;
        }
    }
    return NULL;
}
 
static double satellite_calculate_ber(ptrSUPERFRAME sf, double snr)
{
    ptrCARRIERCONF cc = sf->carrierConfig;
    if (cc->berModel == BERMODEL_Fixed)
        return cc->berValue;
    else if (cc->berModel == BERMODEL_File)
        return calculate_ber(snr, cc->berTable, cc->berTableLen);
    else if (cc->berModel == BERMODEL_Model)
    {
        double dataRate = sf->slotConfig->bitsPerSlot / sf->slotConfig->slotLength_us;
        return Calculate_ber_by_calculation(snr, cc->modulation, dataRate, cc->allocatedBandwidth_Hz / MHZ);
    }
    return 0;
}
 
static PACKET_STATUS satellite_isPacketErrored(ptrSUPERFRAME sf, double bytes, double snr)
{
    double ber = satellite_calculate_ber(sf, snr);
    return fn_NetSim_Packet_DecideError(ber, bytes);
}
 
#ifdef SATELLITE_PROPAGATION_LOG
typedef struct stru_fileinfo
{
    NETSIM_ID t;
    NETSIM_ID ti;
    NETSIM_ID r;
    NETSIM_ID ri;
    
    FILE* fp;
    struct stru_fileinfo* next;
}FILEINFO,*ptrFILEINFO;
ptrFILEINFO fileInfo = NULL;
 
static ptrFILEINFO create_new_log_file(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri)
{
    ptrFILEINFO f = calloc(1, sizeof * f);
    f->t = t;
    f->ti = ti;
    f->r = r;
    f->ri = ri;
    
    char s[BUFSIZ];
    sprintf(s, "%s/log/SatPropLog_%d_%d_%d_%d.csv",
            pszIOPath, t, ti, r, ri);
    f->fp = fopen(s, "w");
    if (!f->fp)
    {
        fnSystemError("Unable to open %s\n", s);
        perror(s);
        free(f);
        return NULL;
    }
    fprintf(f->fp, "Time(Microseconds),ReceivedPower(dBm),FadingLoss(dB),Noise(dBm),SNR(dB)\n");
    ptrFILEINFO tf = fileInfo;
    if (tf)
    {
        while (tf->next) tf = tf->next;
        tf->next = f;
    }
    else
    {
        fileInfo = f;
    }
    return f;
}
 
static FILE* find_log_file(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri)
{
    ptrFILEINFO f = fileInfo;
    while (f)
    {
        if (f->t == t && f->ti == ti && f->r == r && f->ri == ri)
            return f->fp;
        f = f->next;
    }
 
    f = create_new_log_file(t, ti, r, ri);
    return f->fp;
}
 
static void log_power(NETSIM_ID t, NETSIM_ID ti,NETSIM_ID r,NETSIM_ID ri,
                      double p, double f, double n, double snr)
{
    FILE* fp = find_log_file(t, ti, r, ri);
    fprintf(fp, "%lf,%lf,%lf,%lf,%lf,\n",
            ldEventTime, p, f, n, snr);
    fflush(fp);
}
#endif
 
void satellite_check_for_packet_error(NETSIM_ID t, NETSIM_ID ti, NETSIM_ID r, NETSIM_ID ri,
                                      NetSim_PACKET* packet)
{
    double pdbm = satellite_get_rx_power_dbm(t, ti, r, ri);
    double fdb = satellite_get_fading_loss_db(t, ti, r, ri);
    pdbm -= fdb;
 
    double ndbm = satellite_calculate_noise(t, ti, r, ri);
    double snr = satellite_calculate_snr(pdbm, ndbm);
 
#ifdef SATELLITE_PROPAGATION_LOG
    log_power(t, ti, r, ri, pdbm + fdb, fdb, ndbm, snr);
#endif
    double bytes = packet->pstruPhyData->dPacketSize;
 
    ptrSUPERFRAME sf = find_superframe(t, ti, r, ri);
    packet->nPacketStatus = satellite_isPacketErrored(sf, bytes, snr);
}
#pragma endregion