uwranging_tdoa.cpp

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//
// Copyright (c) 2017 Regents of the SIGNET lab, University of Padova.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. Neither the name of the University of Padova (SIGNET lab) nor the
//    names of its contributors may be used to endorse or promote products
//    derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
 
#include "uwranging_tdoa.h"
#include "uwtap_clmsg.h"
#include <clmsg-discovery.h>
#include <clmsg-stats.h>
#include <clsap.h>
#include <cmath>
#include <mac.h>
#include <mmac.h>
#include <tclcl.h>
#include <uwphysical.h>
#include <uwsmposition.h>
#include <uwstats-utilities.h>
 
// define a macro to print debug messages
// 0: NONE  -   1: ERR  -   2: DBG
#define DEBUG(level, text)                                                    \
    {                                                                         \
        if (debug_tdoa >= level) {                                             \
            std::cout << NOW << " UwRangingTDOA(" << node_id << "): " << text \
                      << std::endl;                                           \
        }                                                                     \
    }
static class UwRangingTDOAModuleClass : public TclClass
{
 
public:
    UwRangingTDOAModuleClass()
        : TclClass("Module/UW/RANGING_TDOA")
    {
    }
    TclObject *
    create(int, const char *const *)
    {
        return (new UwRangingTDOA());
    }
 
} class_module_uwrangingtdoa;
 
void
UwRangeTimer::expire(Event *e)
{
    module->throttleTX();
}
 
UwRangingTDOA::UwRangingTDOA()
    : Module()
    , scheduler_active(false)
    , debug_tdoa(0)
    , node_id(0)
    , packet_id(0)
    , n_nodes(0)
    , dist_num(0)
    , range_entries(0)
    , poisson_traffic(0)
    , range_pkts_sent(0)
    , range_bytes_sent(0)
    , range_pkts_recv(0)
    , range_pkts_err(0)
    , saved_entries(0)
    , phy_id(0)
    , queue_size(0)
    , send_timer(this)
    , mac2phy_delay(1e-6)
    , max_tt(5)
    , max_age(10e4)
    , range_period(10)
    , delay_start(0)
    , full_pkt_tx_dur(0)
    , soundspeed(1500.)
    , tof_map()
    , entries_mat()
    , times_mat()
    , last_ids()
    , time_of_flights()
    , entries_timestamps()
    , entry_last_tx()
    , tx_timestamp()
    , ber()
{
    bind("n_nodes_", (int *) &n_nodes);
    bind("debug_tdoa", (int *) &debug_tdoa);
    bind("mac2phy_delay_", (double *) &mac2phy_delay);
    bind("max_tt", (double *) &max_tt);
    bind("range_period", (double *) &range_period);
    bind("delay_start_", (double *) &delay_start);
    bind("poisson_traffic", (int *) &poisson_traffic);
    bind("range_entries", (int *) &range_entries);
    bind("soundspeed", (double *) &soundspeed);
 
    if (n_nodes < 0 || n_nodes > std::numeric_limits<uwrange_node_t>::max()) {
        DEBUG(0, "Negative or too big number of nodes, setting default to 0")
        n_nodes = 0;
    }
 
    dist_num = (n_nodes * (n_nodes - 1) / 2);
    entries_mat.resize(n_nodes,
            std::vector<std::vector<tdoa_entry>>(
                    PKTIDMAX, std::vector<tdoa_entry>(n_nodes, tdoa_entry())));
    times_mat.resize(n_nodes, std::vector<double>(PKTIDMAX, -1.));
    last_ids.resize(n_nodes, -1);
    time_of_flights.resize(dist_num, -1.0);
    entries_timestamps.resize(dist_num, -0.0);
    entry_last_tx.resize(n_nodes, 0.0);
    ber.resize(n_nodes, 0.0);
 
    tof_map.resize(n_nodes, std::vector<int>(n_nodes, -1));
    int temp = 0;
 
    for (int ni = 0; ni < n_nodes; ni++) {
        for (int nj = ni + 1; nj < n_nodes; nj++) {
            tof_map[ni][nj] = temp;
            tof_map[nj][ni] = temp++;
        }
    }
}
 
void
UwRangingTDOA::recv(Packet *p)
{
    hdr_cmn *ch = HDR_CMN(p);
 
    if (ch->direction() == hdr_cmn::UP) {
        if (ch->ptype() != PT_UWRANGING_TDOA)
            sendUp(p);
        else
            Packet::free(p); // Already processed in recvSyncClMsg from UwTAP
    } else if (ch->direction() == hdr_cmn::DOWN) {
        sendDown(p);
    }
}
 
void
UwRangingTDOA::recv(Packet *p, Handler *h)
{
    UwRangingTDOA::recv(p);
}
 
int
UwRangingTDOA::recvSyncClMsg(ClMessage *m)
{
    if (m->type() == CLMSG_TAP_PKT) {
        ClMsgTapPkt *msg = dynamic_cast<ClMsgTapPkt *>(m);
 
        if (msg->clmsg_type == clmsg_tap_type::START_TX) {
            Packet *p = msg->pkt;
 
            if (p) {
                hdr_cmn *ch = HDR_CMN(p);
 
                if (ch->ptype() == PT_UWRANGING_TDOA) {
                    DEBUG(2,
                            "recvSyncClMsg::updating deltas on outgoing packet")
 
                    updateHoldoverTime(p, msg->tx_duration);
                }
            }
 
        } else if (msg->clmsg_type == clmsg_tap_type::END_RX) {
            const Packet *p = msg->pkt;
 
            if (p) {
                hdr_cmn *ch = HDR_CMN(p);
                if (ch->ptype() == PT_UWRANGING_TDOA) {
                    hdr_ranging_tdoa *rangh = HDR_RANGING_TDOA(p);
                    int pkt_node_id = rangh->source_node_id;
                    int pkt_id = rangh->source_pkt_id;
 
                    if (range_entries <= 0) {
                        ClMsgStats stats_clmsg = ClMsgStats(phy_id, UNICAST);
 
                        sendSyncClMsg(&stats_clmsg);
 
                        if (stats_clmsg.getStats()->type_id ==
                                (int) StatsEnum::STATS_PHY_LAYER) {
                            const UwPhysicalStats *stats =
                                    dynamic_cast<const UwPhysicalStats *>(
                                            stats_clmsg.getStats());
 
                            if (stats != 0)
                                ber[pkt_node_id] = stats->last_ber;
 
                        }
                    }
                    if (ch->error()) {
                        DEBUG(1,
                                " RX ERRORED ping with pkt_token_id "
                                << pkt_id << " from node "
                                << pkt_node_id)
 
                        range_pkts_err++;
 
                    } else {
                        range_pkts_recv++;
 
                        DEBUG(2,
                                "recvSyncClMsg::RX ping with pkt_token_id "
                                << pkt_id << " from node "
                                << pkt_node_id)
 
                        rangeRX(p);
                    }
                }
            }
        }
 
        return 0;
 
    } else if (m->type() == CLMSG_TRIGGER_STATS) {
        return 0;
    }
 
    return Module::recvSyncClMsg(m);
}
 
double
UwRangingTDOA::entryWeight(int entry, int pkt_size, int mode) const
{
    double weight = 0;
 
    if (mode == 0) // weight considers only PER
    {
        weight = (pow(1 - ber[entry], pkt_size));
 
        DEBUG(2,
                "entry " << entry << " PER " << pow(1 - ber[entry], pkt_size)
                         << " age " << NOW - entry_last_tx[entry]
                         << " weight: " << weight)
 
    } else if (mode == -1) // weight considers only AGE
    {
        weight = (NOW - entry_last_tx[entry]);
 
        DEBUG(2,
                "entry " << entry << " PER " << pow(1 - ber[entry], pkt_size)
                         << " age " << NOW - entry_last_tx[entry]
                         << " weight: " << weight)
 
    } else if (mode == -2) // weight considers PER * AGE
    {
        weight = (pow(1 - ber[entry], pkt_size) * (NOW - entry_last_tx[entry]));
 
        DEBUG(2,
                "entry " << entry << " PER " << pow(1 - ber[entry], pkt_size)
                         << " age " << NOW - entry_last_tx[entry]
                         << " weight: " << weight)
    }
 
    return weight;
}
 
int
UwRangingTDOA::calcOptEntries(std::vector<int> *sorted_entries) const
{
    int opt_n_entries = (range_entries > 0 ? range_entries : n_nodes - 1);
 
    if (range_entries <= 0)
    {
        std::multimap<double, int, std::greater<double>> sorted_pairs;
        double max_weight = 0.0;
 
        for (int n_entries = 1; n_entries < n_nodes; n_entries++) {
            sorted_pairs.clear();
 
            int pkt_size = 8 * hdr_ranging_tdoa::getSize(n_entries);
 
            for (int entry = 0; entry < n_nodes; entry++) {
                if (entry == node_id)
                    continue;
 
                double w = entryWeight(entry, pkt_size, 0); // weight is just PDR
 
                sorted_pairs.insert(std::pair<double, int>(w, entry));
                DEBUG(2,
                        "entryWeight(" << entry << "," << n_entries
                        << ")= " << w << "")
            }
 
            double weight = 0.0;
            std::multimap<double, int>::iterator iter = sorted_pairs.begin();
 
            for (int i = 0; i < n_entries; i++) // was i < n_entries for considering only best entries
            {
                weight += 1 * (iter->first); // was without n_entries for considering only best entries
                iter++;
                if (iter == sorted_pairs.end())
                    break;
            }
 
            if (weight > max_weight) {
                max_weight = weight;
                opt_n_entries = n_entries;
            }
 
            DEBUG(2,
                    "N entries: " << n_entries << " weight: " << weight << "")
        }
    }
 
    int pkt_size = 8 * hdr_ranging_tdoa::getSize(opt_n_entries);
 
    std::multimap<double, int, std::greater<double>> sorted_pairs;
 
    for (int entry = 0; entry < n_nodes; entry++) {
        if (entry == node_id)
            continue;
 
        sorted_pairs.insert(std::pair<double, int>( entryWeight(entry, pkt_size, range_entries), entry));
    }
 
    std::multimap<double, int>::iterator iter = sorted_pairs.begin();
 
    if (sorted_entries) {
        for (int i = 0; i < opt_n_entries; i++) {
            sorted_entries->push_back(iter->second);
            iter++;
        }
    }
 
    DEBUG(2, "calcOptEntries::opt_n_entries = " << opt_n_entries)
 
    return opt_n_entries;
}
 
void
UwRangingTDOA::rangeTX()
{
    DEBUG(2, "rangeTX")
    Packet *p = Packet::alloc();
    hdr_cmn *ch = HDR_CMN(p);
    hdr_mac *mach = HDR_MAC(p);
    hdr_ranging_tdoa *rangh = HDR_RANGING_TDOA(p);
    ch->ptype() = PT_UWRANGING_TDOA;
    mach->macDA() = MAC_BROADCAST;
    mach->macSA() = node_id;
    mach->ftype() = MF_DATA;
    rangh->source_pkt_id = packet_id;
    rangh->source_node_id = node_id;
    rangh->times_size_ = range_entries;
 
    tx_timestamp.emplace((tx_timestamp.begin() + rangh->source_pkt_id), NOW);
 
    std::vector<int> sorted_entries;
    int j = 0;
 
    DEBUG(2, "rangeTX::calling calcOptEntries rangeID: " << packet_id)
 
    calcOptEntries(&sorted_entries);
    saved_entries += (n_nodes - 1) - sorted_entries.size();
 
    DEBUG(2,
            "rangeTX::OPT SIZE: " << sorted_entries.size() 
            << " n_nodes: " << n_nodes)
 
    for (auto i : sorted_entries) {
        DEBUG(2,
                "rangeTX::times_mat[" << i << "][" << last_ids[i]
                                      << "] = " << times_mat[i][last_ids[i]])
        if (isValid(times_mat[i][last_ids[i]]) && isValid(last_ids[i])) {
            tdoa_entry new_entry =
                    tdoa_entry(NOW - times_mat[i][last_ids[i]], i, last_ids[i]);
 
            (*rangh).times_[j] = new_entry;
            entries_mat[node_id][packet_id][i] = new_entry;
            j++;
 
            DEBUG(2,
                    "rangeTX::entries_mat["
                    << node_id << "][" << packet_id << "][" << i
                    << "].time\t= "
                    << entries_mat[node_id][packet_id][i].time)
        } else {
            DEBUG(1,
                    "rangeTX::entry not valid for node "
                    << i << " times_mat:" << times_mat[i][last_ids[i]]
                    << " last_ids:" << last_ids[i])
        }
    }
 
    ch->size() += rangh->getSize();
    DEBUG(2,
            "rangeTX::queueing range packet with pkt_id: "
            << (int) rangh->source_pkt_id << " and size: " << ch->size()
            << " with # entries: " << (int) rangh->times_size_);
 
    packet_id = (packet_id + 1) % PKTIDMAX;
    last_ids[node_id] = rangh->source_pkt_id;
 
    if (!isValid(rangh->source_pkt_id))
        DEBUG(1,
                "ERROR! invalid pkt_id: " << rangh->source_pkt_id
                << " from node " << rangh->source_node_id)
 
    ++queue_size;
    sendDown(p);
 
    if (UwRangingTDOA::range_period < 0) {
        DEBUG(1,
                "ERROR! packet period set as: " << range_period
                << " but must be >0!!!")
        range_period = 10;
    }
}
 
void
UwRangingTDOA::updateHoldoverTime(Packet *p, double tx_duration)
{
    if (p == NULL) {
        DEBUG(1, "ERROR! updateHoldoverTime() called with NULL packet!")
        return;
    }
 
    hdr_ranging_tdoa *rangh = HDR_RANGING_TDOA(p);
    --queue_size;
    ++range_pkts_sent;
    range_bytes_sent += rangh->getSize();
 
    DEBUG(2,
            "updateHoldoverTime::sending range packet with pkt_id: "
            << (int) rangh->source_pkt_id)
    for (int i = 0; i < rangh->times_size(); i++) {
        DEBUG(2, "updateHoldoverTime::elem[" << i << "]")
        auto &elem = (*rangh).times_[i];
 
        DEBUG(2, "updateHoldoverTime::elem.time = " << elem.time)
 
        elem.time += NOW + tx_duration + mac2phy_delay
                - tx_timestamp[rangh->source_pkt_id];
        entries_mat[node_id][rangh->source_pkt_id][elem.node].time = elem.time;
 
        DEBUG(2, "updateHoldoverTime::tx_duration = " << tx_duration)
        DEBUG(2, "updateHoldoverTime::mac2phy_delay = " << mac2phy_delay)
        DEBUG(2,
                "updateHoldoverTime::tx_timestamp = "
                << tx_timestamp[rangh->source_pkt_id])
        DEBUG(2,
                "updateHoldoverTime::entries_mat["
                << node_id << "][" << (int) rangh->source_pkt_id << "]["
                << (int) elem.node << "].time = " << elem.time)
 
        entry_last_tx[elem.node] = NOW;
    }
 
    times_mat[node_id][rangh->source_pkt_id] = NOW + tx_duration;
 
    DEBUG(2,
            "updateHoldoverTime::times_mat["
                    << node_id << "][" << (int) rangh->source_pkt_id
                    << "] = " << times_mat[node_id][rangh->source_pkt_id])
 
    if (rangh->times_size() == n_nodes - 1)
        full_pkt_tx_dur = tx_duration;
}
 
void
UwRangingTDOA::rangeRX(const Packet *p)
{
    hdr_ranging_tdoa *rangh = HDR_RANGING_TDOA(p);
    int pkt_node_id = rangh->source_node_id;
    int pkt_id = rangh->source_pkt_id;
 
    times_mat[pkt_node_id][pkt_id] = NOW;
    last_ids[pkt_node_id] = pkt_id;
 
    if (!isValid(pkt_id))
        DEBUG(1, "ERROR! invalid pkt_id: "
                << pkt_id << " from node " << pkt_node_id)
 
    for (size_t i = 0; i < entries_mat[pkt_node_id][pkt_id].size(); ++i) {
        // reset all entries relative to the incoming packet present in the matrix
        entries_mat[pkt_node_id][pkt_id][i] = tdoa_entry(-1, i, -1);
    }
 
    double spherical_tof = -1.;
    double spherical_timestamp = -1.;
    for (int i = 0; i < rangh->times_size(); i++) {
        auto &elem = (*rangh).times_[i];
 
        entries_mat[pkt_node_id][pkt_id][elem.node] = elem;
 
        DEBUG(2, "rangeRX::elem[" << i << "]")
        DEBUG(2,
                "rangeRX::entries_mat[" << pkt_node_id << "][" << pkt_id << "]["
                                        << (int) elem.node
                                        << "].time = " << elem.time)
 
        if (elem.node == node_id) { 
            // if packet referred in elem.id is not too old
            if (NOW - times_mat[node_id][elem.id] < max_age) {
                spherical_tof = 
                        (NOW - times_mat[node_id][elem.id] - elem.time) / 2.;
                spherical_timestamp = (NOW + times_mat[node_id][elem.id]) / 2.;
 
                DEBUG(2,
                        "rangeRX::times_mat["
                                << node_id << "][" << (int) elem.id
                                << "] = " << times_mat[node_id][elem.id])
                DEBUG(2, "rangeRX::elem.time = " << elem.time)
                DEBUG(2, "rangeRX::spherical_tof = " << spherical_tof)
 
                if (spherical_tof >= -1e-3 && spherical_tof < max_tt) {
                    time_of_flights[tof_map[pkt_node_id][node_id]] =
                            std::abs(spherical_tof);
                    entries_timestamps[tof_map[pkt_node_id][node_id]] =
                            spherical_timestamp;
                } else {
                    DEBUG(1, "Negative spherical range tt!!! ");
                }
            }
        }
    }
 
    for (int i = 0; i < rangh->times_size(); i++) {
        auto &elem = (*rangh).times_[i];
 
        if (isValid(elem) && elem.node != node_id && isValid(spherical_tof)
                && isValid(times_mat[elem.node][elem.id])
                && isValid(time_of_flights[tof_map[elem.node][node_id]])) {
 
            DEBUG(2, "rangeRX::elem[" << i << "]")
 
            double hyperbolic_tof = (NOW -
                    times_mat[elem.node][elem.id] // RX time from elem.node
                    - spherical_tof // time distance from source node
                    + time_of_flights[tof_map[elem.node][node_id]] // time distance from elem.node
                    - elem.time // holdover between elem.node and source node
                    + mac2phy_delay / (n_nodes-1));
 
            DEBUG(2,
                    "rangeRX::times_mat[" << (int) elem.node << "]["
                                          << (int) elem.id << "] "
                                          << times_mat[elem.node][elem.id])
            DEBUG(2, "rangeRX::spherical_tof = " << spherical_tof)
            DEBUG(2,
                    "rangeRX::time_of_flights["
                            << tof_map[elem.node][node_id] << "] = "
                            << time_of_flights[tof_map[elem.node][node_id]])
            DEBUG(2, "rangeRX::elem.time = " << elem.time)
            DEBUG(2, "rangeRX::hyperbolic_tof = " << hyperbolic_tof)
 
            if (hyperbolic_tof >= -1e-3) {
                time_of_flights[tof_map[pkt_node_id][elem.node]] =
                        std::abs(hyperbolic_tof);
                entries_timestamps[tof_map[pkt_node_id][elem.node]] = 
                        std::min( spherical_timestamp,
                                entries_timestamps[tof_map[elem.node][node_id]]);
            } else {
                DEBUG(1, "Negative hyp range from node "
                                << (int) elem.node << " to " << pkt_node_id);
            }
        }
    }
}
 
bool
UwRangingTDOA::isValid(double value) const
{
    return (value >= 0);
}
 
bool
UwRangingTDOA::isValid(const tdoa_entry &entry) const
{
    return (entry.id >= 0 && entry.node >= 0 && entry.time >= 0);
}
 
int
UwRangingTDOA::command(int argc, const char *const *argv)
{
    Tcl &tcl = Tcl::instance();
    if (argc == 2) {
        if (strcasecmp(argv[1], "start") == 0) {
            start();
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "stop") == 0) {
            stop();
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "sendRange") == 0) {
            rangeTX();
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "getRangePktsTx") == 0) {
            tcl.resultf("%d", range_pkts_sent);
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "getRangePktsRx") == 0) {
            tcl.resultf("%d", range_pkts_recv);
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "getRangeBytesTx") == 0) {
            tcl.resultf("%d", range_bytes_sent);
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "getRangePktsErr") == 0) {
            tcl.resultf("%d", range_pkts_err);
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "getFullPktTime") == 0) {
            tcl.resultf("%f", full_pkt_tx_dur);
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "getSavedEntries") == 0) {
            tcl.resultf("%d", saved_entries);
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "calcOptEntries") == 0) {
            tcl.resultf("%d", calcOptEntries());
            return TCL_OK;
        }
    }
    if (argc == 3) {
        if (strcasecmp(argv[1], "setId") == 0) {
            node_id = atoi(argv[2]);
 
            if (node_id < 0 || node_id > std::numeric_limits<uwrange_node_t>::max())
                return TCL_ERROR;
 
            return TCL_OK;
        }
        if (strcasecmp(argv[1], "setPHYId") == 0) {
            phy_id = atoi(argv[2]);
 
            if (phy_id < 0)
                return TCL_ERROR;
 
            return TCL_OK;
        }
    }
    if (argc == 4) {
        if (strcasecmp(argv[1], "get_distance") == 0) {
            int n1 = atoi(argv[2]);
            int n2 = atoi(argv[3]);
 
            if (n1 >= 0 && n1 < n_nodes && n2 >= 0 && n2 < n_nodes) {
                if (n1 == n2) {
                    tcl.resultf("%.17f", 0.);
                } else {
                    tcl.resultf("%.17f", time_of_flights[tof_map[n1][n2]]);
                }
                return TCL_OK;
            }
            return TCL_ERROR;
        }
    }
    return Module::command(argc, argv);
}
 
void
UwRangingTDOA::start()
{
    scheduler_active = true;
    send_timer.resched(1.0 + delay_start * node_id);
}
 
void
UwRangingTDOA::stop()
{
    scheduler_active = false;
    send_timer.force_cancel();
}
 
void
UwRangingTDOA::throttleTX()
{
    if (scheduler_active)
    {
        int nextTX = range_period;
        if (poisson_traffic) {
            double u = RNG::defaultrng()->uniform_double();
            double lambda = 1. / range_period;
            nextTX = (-log(u) / lambda);
        }
 
        if (queue_size == 0)
            rangeTX();
 
        send_timer.resched(nextTX);
    } else {
        send_timer.force_cancel();
    }
}