Vasil Velichkov | 1828a31 | 2018-05-07 15:55:39 +0300 | [diff] [blame] | 1 | /* -*- c++ -*- */ |
| 2 | /* |
| 3 | * @file |
| 4 | * @author (C) 2018 by Andrew Artyushok <loony.developer@gmail.com> |
| 5 | * @author (C) 2018 by Vasil Velichkov <vvvelichkov@gmail.com> |
| 6 | * @section LICENSE |
| 7 | * |
| 8 | * Gr-gsm is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 3, or (at your option) |
| 11 | * any later version. |
| 12 | * |
| 13 | * Gr-gsm is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with gr-gsm; see the file COPYING. If not, write to |
| 20 | * the Free Software Foundation, Inc., 51 Franklin Street, |
| 21 | * Boston, MA 02110-1301, USA. |
| 22 | */ |
| 23 | |
| 24 | #ifdef HAVE_CONFIG_H |
| 25 | #include "config.h" |
| 26 | #endif |
| 27 | |
| 28 | #include <gnuradio/io_signature.h> |
| 29 | #include "tch_h_chans_demapper_impl.h" |
| 30 | #include <grgsm/endian.h> |
| 31 | #include <grgsm/gsmtap.h> |
| 32 | |
| 33 | #define BURST_SIZE 148 |
| 34 | |
| 35 | namespace gr { |
| 36 | namespace gsm { |
| 37 | |
| 38 | tch_h_chans_demapper::sptr |
| 39 | tch_h_chans_demapper::make(unsigned int timeslot_nr, unsigned int tch_h_channel) |
| 40 | { |
| 41 | return gnuradio::get_initial_sptr |
| 42 | (new tch_h_chans_demapper_impl(timeslot_nr, tch_h_channel)); |
| 43 | } |
| 44 | |
| 45 | /* |
| 46 | * The private constructor |
| 47 | * |
| 48 | */ |
| 49 | tch_h_chans_demapper_impl::tch_h_chans_demapper_impl(unsigned int timeslot_nr, unsigned int tch_h_channel) |
| 50 | : gr::block("tch_h_chans_demapper", |
| 51 | gr::io_signature::make(0, 0, 0), |
| 52 | gr::io_signature::make(0, 0, 0)), |
| 53 | d_timeslot(timeslot_nr), |
| 54 | d_tch_h_channel(tch_h_channel) |
| 55 | |
| 56 | { |
| 57 | //std::cout << "d_tch_type is " << d_tch_type << ", tch_h_channel is " << tch_h_channel << std::endl; |
| 58 | |
| 59 | message_port_register_in(pmt::mp("bursts")); |
| 60 | set_msg_handler(pmt::mp("bursts"), boost::bind(&tch_h_chans_demapper_impl::filter_tch_chans, this, _1)); |
| 61 | message_port_register_out(pmt::mp("tch_bursts")); |
| 62 | message_port_register_out(pmt::mp("acch_bursts")); |
| 63 | } |
| 64 | |
| 65 | /* |
| 66 | * Our virtual destructor. |
| 67 | */ |
| 68 | tch_h_chans_demapper_impl::~tch_h_chans_demapper_impl() |
| 69 | { |
| 70 | } |
| 71 | |
| 72 | void tch_h_chans_demapper_impl::filter_tch_chans(pmt::pmt_t msg) |
| 73 | { |
| 74 | pmt::pmt_t header_plus_burst = pmt::cdr(msg); |
| 75 | gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(header_plus_burst); |
| 76 | if(header->timeslot != d_timeslot) { |
| 77 | return; |
| 78 | } |
| 79 | |
| 80 | uint32_t frame_nr = be32toh(header->frame_number); |
| 81 | uint32_t fn_mod26 = frame_nr % 26; |
| 82 | uint32_t fn_mod13 = frame_nr % 13; |
| 83 | int8_t* burst_bits = (int8_t *)(pmt::blob_data(header_plus_burst)) + sizeof(gsmtap_hdr); |
| 84 | |
| 85 | int8_t new_msg[sizeof(gsmtap_hdr)+BURST_SIZE]; |
| 86 | gsmtap_hdr * new_hdr = (gsmtap_hdr*)new_msg; |
| 87 | memcpy(new_msg, header, sizeof(gsmtap_hdr)+BURST_SIZE); |
| 88 | |
| 89 | new_hdr->sub_type = (fn_mod13 == 12 ? GSMTAP_CHANNEL_ACCH : 0) | GSMTAP_CHANNEL_TCH_H; |
Vasil Velichkov | 7f259fd | 2018-05-06 02:13:36 +0300 | [diff] [blame] | 90 | new_hdr->sub_slot = d_tch_h_channel; |
Vasil Velichkov | 1828a31 | 2018-05-07 15:55:39 +0300 | [diff] [blame] | 91 | |
| 92 | pmt::pmt_t msg_binary_blob = pmt::make_blob(new_msg,sizeof(gsmtap_hdr)+BURST_SIZE); |
| 93 | pmt::pmt_t msg_out = pmt::cons(pmt::PMT_NIL, msg_binary_blob); |
| 94 | |
| 95 | //distinguishing uplink and downlink bursts |
| 96 | bool uplink_burst = (be16toh(header->arfcn) & 0x4000) ? true : false; |
| 97 | |
| 98 | if(uplink_burst) |
| 99 | { |
| 100 | sacch_tch_demapper(fn_mod13, fn_mod26, frame_nr, d_bursts_sacch_ul, |
| 101 | d_frame_numbers_sacch_ul, d_bursts_ul, d_frame_numbers_ul, msg_out); |
| 102 | } |
| 103 | else |
| 104 | { |
| 105 | sacch_tch_demapper(fn_mod13, fn_mod26, frame_nr, d_bursts_sacch_dl, |
| 106 | d_frame_numbers_sacch_dl, d_bursts_dl, d_frame_numbers_dl, msg_out); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | void tch_h_chans_demapper_impl::sacch_tch_demapper(uint32_t fn_mod13, u_int32_t fn_mod26, uint32_t frame_nr, |
| 111 | pmt::pmt_t *d_bursts_sacch, |
| 112 | uint32_t *d_frame_numbers_sacch, pmt::pmt_t d_bursts[3][8], |
| 113 | uint32_t d_frame_numbers[3][8], pmt::pmt_t msg_out) |
| 114 | { |
| 115 | bool frames_are_consecutive = true; |
| 116 | if (fn_mod13 == 12) |
| 117 | { |
| 118 | // position of SACCH burst based on timeslot |
| 119 | // see specification gsm 05.02 |
| 120 | uint32_t index; |
| 121 | bool is_sacch = false; |
| 122 | |
| 123 | if (d_tch_h_channel == 0 && fn_mod26 == 12) |
| 124 | { |
| 125 | index = (((frame_nr - 12) / 26) - (d_timeslot / 2)) % 4; |
| 126 | is_sacch = true; |
| 127 | } |
| 128 | else if (d_tch_h_channel == 1 && fn_mod26 == 25) |
| 129 | { |
| 130 | index = (((frame_nr - 25) / 26) - (d_timeslot / 2)) % 4; |
| 131 | is_sacch = true; |
| 132 | } |
| 133 | |
| 134 | if (is_sacch) |
| 135 | { |
| 136 | d_bursts_sacch[index] = msg_out; |
| 137 | d_frame_numbers_sacch[index] = frame_nr; |
| 138 | |
| 139 | if (index == 3) |
| 140 | { |
| 141 | //check for a situation where some bursts were lost |
| 142 | //in this situation frame numbers won't be consecutive |
| 143 | frames_are_consecutive = true; |
| 144 | for(int jj=1; jj<4; jj++) |
| 145 | { |
| 146 | if((d_frame_numbers_sacch[jj]-d_frame_numbers_sacch[jj-1]) != 26) |
| 147 | { |
| 148 | frames_are_consecutive = false; |
| 149 | } |
| 150 | } |
| 151 | if(frames_are_consecutive) |
| 152 | { |
| 153 | //send bursts to the output |
| 154 | for(int jj=0; jj<4; jj++) |
| 155 | { |
| 156 | message_port_pub(pmt::mp("acch_bursts"), d_bursts_sacch[jj]); |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | else |
| 163 | { |
| 164 | bool our_sub=false; |
| 165 | // So, here I change the fn_mod13, with this changes I can |
| 166 | // process both subslot (d_tch_h_channel) with the same code. |
| 167 | // |
| 168 | // Theory about this on github |
| 169 | // |
| 170 | // Example: |
| 171 | // |
| 172 | // For subslot=0 our burst is 0,2,4,6 etc |
| 173 | // For subslot=1 it 1,3,5 etc |
| 174 | // But if we change it with this code, |
| 175 | // both will be 0,1,2,3,4 etc |
| 176 | // And we can proced two subslot like one. |
| 177 | if(fn_mod13%2==d_tch_h_channel) { |
| 178 | if(d_tch_h_channel==0) { |
| 179 | fn_mod13=fn_mod13/2; |
| 180 | }else{ |
| 181 | fn_mod13-=1; |
| 182 | fn_mod13=fn_mod13/2; |
| 183 | } |
| 184 | // We work only with our subslot |
| 185 | our_sub=true; |
| 186 | } |
| 187 | if(our_sub) { |
| 188 | |
| 189 | if (fn_mod13 <= 1) |
| 190 | { |
| 191 | // add to b1 and b3 |
| 192 | d_bursts[0][fn_mod13] = msg_out; |
| 193 | d_bursts[2][fn_mod13+2] = msg_out; |
| 194 | |
| 195 | |
| 196 | |
| 197 | d_frame_numbers[0][fn_mod13] = frame_nr; |
| 198 | d_frame_numbers[2][fn_mod13+2] = frame_nr; |
| 199 | } |
| 200 | else if (fn_mod13 >=2 && fn_mod13 <=3) |
| 201 | { |
| 202 | // add to b1 and b2 |
| 203 | d_bursts[0][fn_mod13] = msg_out; |
| 204 | d_bursts[1][fn_mod13-2] = msg_out; |
| 205 | |
| 206 | |
| 207 | d_frame_numbers[0][fn_mod13] = frame_nr; |
| 208 | d_frame_numbers[1][fn_mod13-2] = frame_nr; |
| 209 | //d_frame_numbers[1][fn_mod13 - 4] = frame_nr; |
| 210 | } |
| 211 | else if (fn_mod13 >=4 && fn_mod13 <=5) |
| 212 | { |
| 213 | // add to b1 and b2 |
| 214 | d_bursts[1][fn_mod13-2] = msg_out; |
| 215 | d_bursts[2][fn_mod13-4] = msg_out; |
| 216 | |
| 217 | |
| 218 | |
| 219 | d_frame_numbers[1][fn_mod13-2] = frame_nr; |
| 220 | d_frame_numbers[2][fn_mod13-4] = frame_nr; |
| 221 | //d_frame_numbers[1][fn_mod13 - 4] = frame_nr; |
| 222 | } |
| 223 | // send burst 1 or burst 2 to output |
| 224 | //if ( fn_mod26 == 2 || fn_mod26 == 5 || fn_mod26 == 9) |
| 225 | if(fn_mod13 == 1 || fn_mod13 == 3|| fn_mod13 == 5) |
| 226 | { |
| 227 | int tch_burst_nr = 0; |
| 228 | |
| 229 | if(fn_mod13==5) { |
| 230 | tch_burst_nr = 1; |
| 231 | } |
| 232 | if(fn_mod13==1) { |
| 233 | tch_burst_nr = 2; |
| 234 | } |
| 235 | |
| 236 | //check for a situation where some bursts were lost |
| 237 | //in this situation frame numbers won't be consecutive |
| 238 | frames_are_consecutive = true; |
| 239 | // std::cout<<"br="<<tch_burst_nr<<" Array: "; |
| 240 | // std::cout<<d_frame_numbers[tch_burst_nr][0]<<" "; |
| 241 | bool one_tree=true; |
| 242 | for(int jj=1; jj<4; jj++) |
| 243 | { |
| 244 | |
| 245 | if (((d_frame_numbers[tch_burst_nr][jj] - d_frame_numbers[tch_burst_nr][jj-1]) != 2) && frames_are_consecutive) |
| 246 | { |
| 247 | frames_are_consecutive = false; |
| 248 | |
| 249 | if (tch_burst_nr == 2 && jj == 2 |
| 250 | && d_frame_numbers[tch_burst_nr][jj] - d_frame_numbers[tch_burst_nr][jj - 1] == 3) |
| 251 | { |
| 252 | // std::cout<<" YEAH "; |
| 253 | frames_are_consecutive = true; |
| 254 | } |
| 255 | |
| 256 | } |
| 257 | //} |
| 258 | } |
| 259 | // std::cout<<std::endl; |
| 260 | |
| 261 | if(frames_are_consecutive) |
| 262 | { |
| 263 | |
| 264 | for(int jj=0; jj<4; jj++) |
| 265 | { |
| 266 | |
| 267 | message_port_pub(pmt::mp("tch_bursts"), d_bursts[tch_burst_nr][jj]); |
| 268 | } |
| 269 | |
| 270 | // useless |
| 271 | // d_bursts_stolen[tch_burst_nr] = false; |
| 272 | } |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | } |
| 277 | } |
| 278 | } /* namespace gsm */ |
| 279 | } /* namespace gr */ |