103 lines
3.3 KiB
C++
103 lines
3.3 KiB
C++
/* -*- c++ -*- */
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/*
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* @file
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* @author Piotr Krysik <ptrkrysik@gmail.com>
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* @section LICENSE
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*
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* Gr-gsm is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* Gr-gsm is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with gr-gsm; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <gnuradio/io_signature.h>
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#include <gsm/endian.h>
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#include <gsm/gsmtap.h>
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#include "get_bcch_or_ccch_bursts_impl.h"
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namespace gr {
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namespace gsm {
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get_bcch_or_ccch_bursts::sptr
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get_bcch_or_ccch_bursts::make(unsigned int fn51_start)
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{
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return gnuradio::get_initial_sptr
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(new get_bcch_or_ccch_bursts_impl(fn51_start));
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}
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/*
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* The private constructor
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*/
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get_bcch_or_ccch_bursts_impl::get_bcch_or_ccch_bursts_impl(unsigned int fn51_start)
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: gr::block("get_bcch_or_ccch_bursts",
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gr::io_signature::make(0, 0, 0),
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gr::io_signature::make(0, 0, 0)),
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d_fn51_start(fn51_start)
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{
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message_port_register_in(pmt::mp("bursts"));
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set_msg_handler(pmt::mp("bursts"), boost::bind(&get_bcch_or_ccch_bursts_impl::filter_ccch, this, _1));
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message_port_register_out(pmt::mp("bursts"));
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}
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/*
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* Our virtual destructor.
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*/
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get_bcch_or_ccch_bursts_impl::~get_bcch_or_ccch_bursts_impl()
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{
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}
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void get_bcch_or_ccch_bursts_impl::filter_ccch(pmt::pmt_t msg)
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{
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pmt::pmt_t header_plus_burst = pmt::cdr(msg);
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gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(header_plus_burst);
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uint32_t frame_nr = be32toh(header->frame_number);
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uint32_t fn_mod51 = frame_nr % 51;
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int fn51_stop = d_fn51_start+3;
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if(header->timeslot==0){
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if(fn_mod51>=d_fn51_start && fn_mod51<=fn51_stop){
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uint32_t ii = fn_mod51-d_fn51_start;
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d_frame_numbers[ii]=frame_nr;
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d_bursts[ii] = msg;
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}
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if(fn_mod51==fn51_stop){
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//check for a situation where some BCCH bursts were lost
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//in this situation frame numbers won't be consecutive
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bool frames_are_consecutive = true;
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for(int jj=1; jj<4; jj++)
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{
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if((d_frame_numbers[jj]-d_frame_numbers[jj-1])!=1){
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frames_are_consecutive = false;
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}
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}
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if(frames_are_consecutive)
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{
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//send bursts to the output
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for(int jj=0; jj<4; jj++)
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{
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message_port_pub(pmt::mp("bursts"), d_bursts[jj]);
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}
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}
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}
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}
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}
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} /* namespace gsm */
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} /* namespace gr */
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