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/* -*- c++ -*- */
/*
* Copyright 2014 <+YOU OR YOUR COMPANY+>.
*
* This 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.
*
* This software 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 software; 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 <gsm/gsmtap.h>
#include "get_bcch_or_ccch_bursts_impl.h"
namespace gr {
namespace gsm {
get_bcch_or_ccch_bursts::sptr
get_bcch_or_ccch_bursts::make(unsigned int fn51_start)
{
return gnuradio::get_initial_sptr
(new get_bcch_or_ccch_bursts_impl(fn51_start));
}
/*
* The private constructor
*/
get_bcch_or_ccch_bursts_impl::get_bcch_or_ccch_bursts_impl(unsigned int fn51_start)
: gr::block("get_bcch_or_ccch_bursts",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(0, 0, 0)),
d_fn51_start(fn51_start)
{
message_port_register_in(pmt::mp("bursts"));
set_msg_handler(pmt::mp("bursts"), boost::bind(&get_bcch_or_ccch_bursts_impl::filter_ccch, this, _1));
message_port_register_out(pmt::mp("bursts"));
}
/*
* Our virtual destructor.
*/
get_bcch_or_ccch_bursts_impl::~get_bcch_or_ccch_bursts_impl()
{
}
void get_bcch_or_ccch_bursts_impl::filter_ccch(pmt::pmt_t msg)
{
pmt::pmt_t header_blob = pmt::car(msg);
pmt::pmt_t content = pmt::cdr(msg);
gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(header_blob);
uint32_t frame_nr = be32toh(header->frame_number);
uint32_t fn_mod51 = frame_nr % 51;
int fn51_stop = d_fn51_start+3;
if(header->timeslot==0){
if(fn_mod51>=d_fn51_start && fn_mod51<=fn51_stop){
uint32_t ii = fn_mod51-d_fn51_start;
d_frame_numbers[ii]=frame_nr;
d_bursts[ii] = msg;
}
if(fn_mod51==fn51_stop){
//check for a situation where some BCCH bursts were lost
//in this situation frame numbers won't be consecutive
bool frames_are_consecutive = true;
for(int jj=1; jj<4; jj++)
{
if((d_frame_numbers[jj]-d_frame_numbers[jj-1])!=1){
frames_are_consecutive = false;
}
}
if(frames_are_consecutive)
{
//send bursts to the output
for(int jj=0; jj<4; jj++)
{
message_port_pub(pmt::mp("bursts"), d_bursts[jj]);
}
}
}
}
}
} /* namespace gsm */
} /* namespace gr */
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