Merge branch 'ptrkrysik/trx' into development

7 files changed, 581 insertions, 0 deletions

diff --git a/lib/transmitter/CMakeLists.txt b/lib/transmitter/CMakeLists.txt
new file mode 100644
index 0000000..eb53162
--- /dev/null
+++ b/lib/transmitter/CMakeLists.txt
@@ -0,0 +1,24 @@
+# Copyright 2011,2012 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio 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.
+#
+# GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+
+add_sources(
+   txtime_setter_impl.cc
+   preprocess_tx_burst_impl.cc
+   gen_test_ab_impl
+)
diff --git a/lib/transmitter/gen_test_ab_impl.cc b/lib/transmitter/gen_test_ab_impl.cc
new file mode 100644
index 0000000..bb9c9f6
--- /dev/null
+++ b/lib/transmitter/gen_test_ab_impl.cc
@@ -0,0 +1,107 @@
+/* -*- c++ -*- */
+/* @file
+ * @author Piotr Krysik <ptrkrysik@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/gsmtap.h>
+#include <grgsm/gsm_constants.h>
+#include "gen_test_ab_impl.h"
+
+namespace gr {
+  namespace gsm {
+
+    static uint8_t rach_synch_seq[] = {
+      0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1,
+      1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0  ,
+      1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0,
+    };
+  
+    static uint8_t AB[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+//    static uint8_t AB[] = {0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1};
+// static uint8_t AB[] = { 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1};
+//  static uint8_t AB[] = {1,1,1,1,1,1,1,1,1,0,1,1,0,1,0,0,1,0,0,0,0,0,0,0,0,1,1,0,0,1,1,0,0,1,0,1,0,1,0,1,1,1,0,0,0,0,1,1,1,0,0,1,0,0,0,1,0,1,0,1,0,0,1,0,1,0,1,1,0,1,1,0,0,1,0,1,0,0,0,1,1,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
+//  ,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1};
+    gen_test_ab::sptr
+    gen_test_ab::make()
+    {
+      return gnuradio::get_initial_sptr
+        (new gen_test_ab_impl());
+    }
+
+    /*
+     * The private constructor
+     */
+    gen_test_ab_impl::gen_test_ab_impl()
+      : gr::block("gen_test_ab",
+              gr::io_signature::make(0, 0, 0),
+              gr::io_signature::make(0, 0, 0))
+    {
+        message_port_register_in(pmt::intern("bursts_in"));
+        message_port_register_out(pmt::intern("bursts_out"));
+
+        set_msg_handler(pmt::intern("bursts_in"),  boost::bind(&gen_test_ab_impl::generate_ab,   this, _1));
+    }
+
+    /*
+     * Our virtual destructor.
+     */
+    gen_test_ab_impl::~gen_test_ab_impl()
+    {
+    }
+    
+    void gen_test_ab_impl::generate_ab(pmt::pmt_t burst)
+    {
+        uint8_t buf[sizeof(gsmtap_hdr) + 148];
+        struct gsmtap_hdr *tap_header = (struct gsmtap_hdr *) buf;
+        uint8_t *access_burst = buf + sizeof(gsmtap_hdr);
+
+//        memset(access_burst, 0, 8); /* TB */
+//        memcpy(access_burst + 8, rach_synch_seq, 41); /* sync seq */
+//        memcpy(access_burst + 49, AB, 36); /* payload */
+//        memset(access_burst + 85, 0, 63); /* TB + GP */
+        
+        memcpy(access_burst, AB, 148);
+        
+        gsmtap_hdr * header = (gsmtap_hdr *)(pmt::blob_data(pmt::cdr(burst)));
+        uint32_t frame_nr = be32toh(header->frame_number);
+        frame_nr = (frame_nr+51)% (26*51*2048);
+        
+        tap_header->version = GSMTAP_VERSION;
+        tap_header->hdr_len = sizeof(gsmtap_hdr) / 4;
+        tap_header->type = GSMTAP_TYPE_UM_BURST;
+        tap_header->sub_type = GSMTAP_BURST_ACCESS;
+        tap_header->frame_number = htobe32(frame_nr);
+        tap_header->timeslot = header->timeslot;
+        tap_header->arfcn = 0;
+        
+        pmt::pmt_t blob = pmt::make_blob(buf, sizeof(gsmtap_hdr) + BURST_SIZE);
+        pmt::pmt_t pdu_header = pmt::make_dict();
+        
+        pmt::pmt_t new_msg = pmt::cons(pdu_header, blob);
+        message_port_pub(pmt::intern("bursts_out"), new_msg);
+    }
+  } /* namespace gsm */
+} /* namespace gr */
+
diff --git a/lib/transmitter/gen_test_ab_impl.h b/lib/transmitter/gen_test_ab_impl.h
new file mode 100644
index 0000000..366481e
--- /dev/null
+++ b/lib/transmitter/gen_test_ab_impl.h
@@ -0,0 +1,47 @@
+/* -*- c++ -*- */
+/* @file
+ * @author Piotr Krysik <ptrkrysik@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.
+ * 
+ */
+
+#ifndef INCLUDED_GSM_GEN_TEST_AB_IMPL_H
+#define INCLUDED_GSM_GEN_TEST_AB_IMPL_H
+
+#include <grgsm/transmitter/gen_test_ab.h>
+#include <grgsm/misc_utils/time_spec.h>
+#include <grgsm/misc_utils/fn_time.h>
+
+namespace gr {
+  namespace gsm {
+
+    class gen_test_ab_impl : public gen_test_ab
+    {
+     private:
+      void generate_ab(pmt::pmt_t burst);
+      
+     public:
+      gen_test_ab_impl();
+      ~gen_test_ab_impl();
+    };
+
+  } // namespace gsm
+} // namespace gr
+
+#endif /* INCLUDED_GSM_GEN_TEST_AB_IMPL_H */
+
diff --git a/lib/transmitter/preprocess_tx_burst_impl.cc b/lib/transmitter/preprocess_tx_burst_impl.cc
new file mode 100644
index 0000000..5fbac98
--- /dev/null
+++ b/lib/transmitter/preprocess_tx_burst_impl.cc
@@ -0,0 +1,96 @@
+/* -*- 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 <assert.h>
+
+#include <gnuradio/io_signature.h>
+#include <grgsm/gsm_constants.h>
+#include <grgsm/gsmtap.h>
+
+#include "preprocess_tx_burst_impl.h"
+
+namespace gr {
+  namespace gsm {
+
+    preprocess_tx_burst::sptr
+    preprocess_tx_burst::make()
+    {
+      return gnuradio::get_initial_sptr
+        (new preprocess_tx_burst_impl());
+    }
+
+    /*
+     * The private constructor
+     */
+    preprocess_tx_burst_impl::preprocess_tx_burst_impl()
+      : gr::block("preprocess_tx_burst",
+        gr::io_signature::make(0, 0, 0),
+        gr::io_signature::make(0, 0, 0))
+    {
+        message_port_register_in(pmt::mp("bursts_in"));
+        message_port_register_out(pmt::mp("bursts_out"));
+
+        set_msg_handler(pmt::mp("bursts_in"),
+          boost::bind(&preprocess_tx_burst_impl::process_burst, this, _1));
+    }
+
+    /*
+     * Our virtual destructor.
+     */
+    preprocess_tx_burst_impl::~preprocess_tx_burst_impl()
+    {
+    }
+    
+    void preprocess_tx_burst_impl::process_burst(pmt::pmt_t msg_in)
+    {
+      pmt::pmt_t blob_in = pmt::cdr(msg_in);
+
+      // Extract GSMTAP header from message
+      gsmtap_hdr *burst_hdr = (gsmtap_hdr *) pmt::blob_data(blob_in);
+
+      // Extract burst bits from message
+      uint8_t *burst_bits = (uint8_t *)
+        (pmt::blob_data(blob_in)) + sizeof(gsmtap_hdr);
+
+      // Determine and check burst length
+      size_t burst_len = pmt::blob_length(blob_in) - sizeof(gsmtap_hdr);
+      assert(burst_len == BURST_SIZE);
+
+      // The Access Burst last has reduced length
+      if (burst_hdr->sub_type == GSMTAP_BURST_ACCESS)
+        burst_len = ACCESS_BURST_SIZE;
+
+      // Prepare an output message
+      pmt::pmt_t blob_out = pmt::make_blob(burst_bits, burst_len);
+      pmt::pmt_t msg_out = pmt::cons(pmt::car(msg_in), blob_out);
+
+      /* Send a message to the output */
+      message_port_pub(pmt::mp("bursts_out"), msg_out);
+    }
+
+  } /* namespace gsm */
+} /* namespace gr */
diff --git a/lib/transmitter/preprocess_tx_burst_impl.h b/lib/transmitter/preprocess_tx_burst_impl.h
new file mode 100644
index 0000000..27fc508
--- /dev/null
+++ b/lib/transmitter/preprocess_tx_burst_impl.h
@@ -0,0 +1,47 @@
+/* -*- c++ -*- */
+/* @file
+ * @author Piotr Krysik <ptrkrysik@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.
+ * 
+ */
+
+#ifndef INCLUDED_GSM_PREPROCESS_TX_BURST_IMPL_H
+#define INCLUDED_GSM_PREPROCESS_TX_BURST_IMPL_H
+
+#include <grgsm/transmitter/preprocess_tx_burst.h>
+#include <grgsm/misc_utils/time_spec.h>
+#include <grgsm/misc_utils/fn_time.h>
+
+namespace gr {
+  namespace gsm {
+
+    class preprocess_tx_burst_impl : public preprocess_tx_burst
+    {
+     private:
+      void process_burst(pmt::pmt_t burst);
+      
+     public:
+      preprocess_tx_burst_impl();
+      ~preprocess_tx_burst_impl();
+    };
+
+  } // namespace gsm
+} // namespace gr
+
+#endif /* INCLUDED_GSM_PREPROCESS_TX_BURST_IMPL_H */
+
diff --git a/lib/transmitter/txtime_setter_impl.cc b/lib/transmitter/txtime_setter_impl.cc
new file mode 100644
index 0000000..33bc994
--- /dev/null
+++ b/lib/transmitter/txtime_setter_impl.cc
@@ -0,0 +1,196 @@
+/* -*- 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/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 not_found = pmt::intern("not_found");
+      pmt::pmt_t fn_time, time_hint;
+
+      fn_time = pmt::dict_ref(msg,
+        pmt::intern("fn_time"), not_found);
+      time_hint = pmt::dict_ref(msg,
+        pmt::intern("fn_time"), not_found);
+
+      if (fn_time != not_found) {
+        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 != not_found) {
+        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)
+    {
+      if (d_fn_ref != UNKNOWN_FN)
+      {
+        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;
+
+        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 */
diff --git a/lib/transmitter/txtime_setter_impl.h b/lib/transmitter/txtime_setter_impl.h
new file mode 100644
index 0000000..62f500a
--- /dev/null
+++ b/lib/transmitter/txtime_setter_impl.h
@@ -0,0 +1,64 @@
+/* -*- c++ -*- */
+/* @file
+ * @author Piotr Krysik <ptrkrysik@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.
+ * 
+ */
+
+#ifndef INCLUDED_GSM_TXTIME_SETTER_IMPL_H
+#define INCLUDED_GSM_TXTIME_SETTER_IMPL_H
+
+#include <grgsm/transmitter/txtime_setter.h>
+#include <grgsm/misc_utils/time_spec.h>
+#include <grgsm/misc_utils/fn_time.h>
+
+namespace gr {
+  namespace gsm {
+
+    class txtime_setter_impl : public txtime_setter
+    {
+     private:
+      uint32_t d_fn_ref;
+      uint32_t d_ts_ref;
+      time_format d_time_ref;
+      time_format d_time_hint;
+      double d_timing_advance;
+      double d_delay_correction;
+
+      void process_fn_time_reference(pmt::pmt_t msg);
+      void process_txtime_of_burst(pmt::pmt_t msg);
+
+     public:
+      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);
+      ~txtime_setter_impl();
+
+      // Where all the action really happens
+      void set_fn_time_reference(uint32_t fn, uint32_t ts,
+        uint64_t time_secs, double time_fracs);
+      void set_time_hint(uint64_t time_hint_secs, double time_hint_fracs);
+      void set_delay_correction(double delay_correction);
+      void set_timing_advance(double timing_advance);
+    };
+
+  } // namespace gsm
+} // namespace gr
+
+#endif /* INCLUDED_GSM_TXTIME_SETTER_IMPL_H */