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/* -*- c++ -*- */
/* @file
* @author Piotr Krysik <ptrkrysik@gmail.com>
* @author Vadim Yanitskiy <axilirator@gmail.com>
* @section LICENSE
*
* Gr-gsm is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* Gr-gsm 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 gr-gsm; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gnuradio/io_signature.h>
#include <grgsm/endian.h>
#include <grgsm/gsmtap.h>
#include "txtime_setter_impl.h"
#define UNKNOWN_FN 0xffffffff
#define MAX_EARLY_TIME_DIFF 10.0
namespace gr {
namespace gsm {
txtime_setter::sptr
txtime_setter::make(
uint32_t init_fn, uint64_t init_time_secs,
double init_time_fracs, uint64_t time_hint_secs,
double time_hint_fracs, double timing_advance,
double delay_correction)
{
return gnuradio::get_initial_sptr
(new txtime_setter_impl(init_fn, init_time_secs,
init_time_fracs, time_hint_secs, time_hint_fracs,
timing_advance, delay_correction));
}
/*
* The private constructor
*/
txtime_setter_impl::txtime_setter_impl(
uint32_t init_fn, uint64_t init_time_secs,
double init_time_fracs, uint64_t time_hint_secs,
double time_hint_fracs, double timing_advance,
double delay_correction
) : gr::block("txtime_setter",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(0, 0, 0)),
d_time_hint(time_hint_secs,time_hint_fracs),
d_time_ref(init_time_secs,init_time_fracs),
d_delay_correction(delay_correction),
d_timing_advance(timing_advance),
d_fn_ref(init_fn),
d_ts_ref(0)
{
// Register I/O ports
message_port_register_in(pmt::mp("fn_time"));
message_port_register_in(pmt::mp("bursts_in"));
message_port_register_out(pmt::mp("bursts_out"));
// Bind message handlers
set_msg_handler(pmt::mp("fn_time"),
boost::bind(&txtime_setter_impl::process_fn_time_reference,
this, _1));
set_msg_handler(pmt::mp("bursts_in"),
boost::bind(&txtime_setter_impl::process_txtime_of_burst,
this, _1));
}
/*
* Our virtual destructor.
*/
txtime_setter_impl::~txtime_setter_impl()
{
}
void txtime_setter_impl::process_fn_time_reference(pmt::pmt_t msg)
{
pmt::pmt_t fn_time, time_hint;
fn_time = pmt::dict_ref(msg,
pmt::intern("fn_time"), pmt::PMT_NIL);
time_hint = pmt::dict_ref(msg,
pmt::intern("time_hint"), pmt::PMT_NIL);
if (fn_time != pmt::PMT_NIL) {
uint32_t fn_ref = static_cast<uint32_t>
(pmt::to_uint64(pmt::car(pmt::car(fn_time))));
uint32_t ts = static_cast<uint32_t>
(pmt::to_uint64(pmt::cdr(pmt::car(fn_time))));
uint64_t time_secs = pmt::to_uint64(
pmt::car(pmt::cdr(fn_time)));
double time_fracs = pmt::to_double(
pmt::cdr(pmt::cdr(fn_time)));
set_fn_time_reference(fn_ref, ts, time_secs, time_fracs);
} else if (time_hint != pmt::PMT_NIL) {
set_time_hint(pmt::to_uint64(pmt::car(fn_time)),
pmt::to_double(pmt::cdr(fn_time)));
}
}
void txtime_setter_impl::process_txtime_of_burst(pmt::pmt_t msg_in)
{
pmt::pmt_t blob = pmt::cdr(msg_in);
// Extract GSMTAP header from message
gsmtap_hdr *header = (gsmtap_hdr *) pmt::blob_data(blob);
uint32_t frame_nr = be32toh(header->frame_number);
uint32_t ts_num = header->timeslot;
if (d_fn_ref == UNKNOWN_FN) {
std::cout << "Missing reference TDMA frame number, dropping "
<< format("burst (fn=%u, tn=%u)", frame_nr, ts_num)
<< std::endl;
return;
}
time_format txtime = fn_time_delta_cpp(d_fn_ref, d_time_ref,
frame_nr, d_time_hint, ts_num, d_ts_ref);
time_spec_t txtime_spec = time_spec_t(txtime.first, txtime.second);
txtime_spec -= d_delay_correction;
txtime_spec -= d_timing_advance;
time_spec_t current_time_estimate = time_spec_t(d_time_hint.first, d_time_hint.second);
if (txtime_spec <= current_time_estimate) { // Drop too late bursts
std::cout << "lB" << std::flush;
} else if (txtime_spec > current_time_estimate + MAX_EARLY_TIME_DIFF) { // Drop too early bursts
std::cout << "eB" << std::flush; //TODO: too early condition might happen when changing BTSes.
//Wrong fn_time is applied to new or old bursts in such situation.
//This solution is not perfect as MS might be blocked upto
//MAX_EARLY_TIME_DIFF seconds.
//Better solution would be to indentify fn_time and burst coming
//from given BTS (i.e. based on ARFCN) and dropping bursts for which
//the bts_id doesn't match with bts_id of fn_time.
} else { //process bursts that are in the right time-frame
pmt::pmt_t tags_dict = pmt::dict_add(
pmt::make_dict(),
pmt::intern("tx_time"),
pmt::make_tuple(
pmt::from_uint64(txtime_spec.get_full_secs()),
pmt::from_double(txtime_spec.get_frac_secs()))
);
tags_dict = pmt::dict_add(tags_dict,
pmt::intern("fn"), pmt::from_uint64(frame_nr));
tags_dict = pmt::dict_add(tags_dict,
pmt::intern("ts"), pmt::from_uint64(ts_num));
// Send a message to the output
pmt::pmt_t msg_out = pmt::cons(tags_dict, pmt::cdr(msg_in));
message_port_pub(pmt::mp("bursts_out"), msg_out);
}
}
void txtime_setter_impl::set_fn_time_reference(
uint32_t fn, uint32_t ts, uint64_t time_secs,
double time_fracs)
{
d_fn_ref = fn;
d_ts_ref = ts;
d_time_ref = std::make_pair(time_secs, time_fracs);
set_time_hint(time_secs, time_fracs);
}
void txtime_setter_impl::set_time_hint(
uint64_t time_hint_secs, double time_hint_fracs)
{
d_time_hint = std::make_pair(time_hint_secs, time_hint_fracs);
}
void txtime_setter_impl::set_delay_correction(double delay_correction)
{
d_delay_correction = delay_correction;
}
void txtime_setter_impl::set_timing_advance(double timing_advance)
{
d_timing_advance = timing_advance;
}
} /* namespace gsm */
} /* namespace gr */
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