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/* Generic GSM utility routines */
/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <stdint.h>
#include <gsm.h>
enum gsm_band gsm_arfcn2band(uint16_t arfcn)
{
if (arfcn & ARFCN_PCS)
return GSM_1900;
else if (arfcn <= 124)
return GSM_900;
else if (arfcn >= 955 && arfcn <= 1023)
return GSM_900;
else if (arfcn >= 128 && arfcn <= 251)
return GSM_850;
else if (arfcn >= 512 && arfcn <= 885)
return GSM_1800;
else if (arfcn >= 259 && arfcn <= 293)
return GSM_450;
else if (arfcn >= 306 && arfcn <= 340)
return GSM_480;
else if (arfcn >= 350 && arfcn <= 425)
return GSM_810;
else if (arfcn >= 438 && arfcn <= 511)
return GSM_750;
else
return GSM_1800;
}
/* Convert an ARFCN to the frequency in MHz * 10 */
uint16_t gsm_arfcn2freq10(uint16_t arfcn, int uplink)
{
uint16_t freq10_ul;
uint16_t freq10_dl;
if (arfcn & ARFCN_PCS) {
/* DCS 1900 */
arfcn &= ~ARFCN_PCS;
freq10_ul = 18502 + 2 * (arfcn-512);
freq10_dl = freq10_ul + 800;
} else if (arfcn <= 124) {
/* Primary GSM + ARFCN 0 of E-GSM */
freq10_ul = 8900 + 2 * arfcn;
freq10_dl = freq10_ul + 450;
} else if (arfcn >= 955 && arfcn <= 1023) {
/* E-GSM and R-GSM */
freq10_ul = 8900 + 2 * (arfcn - 1024);
freq10_dl = freq10_ul + 450;
} else if (arfcn >= 128 && arfcn <= 251) {
/* GSM 850 */
freq10_ul = 8242 + 2 * (arfcn - 128);
freq10_dl = freq10_ul + 450;
} else if (arfcn >= 512 && arfcn <= 885) {
/* DCS 1800 */
freq10_ul = 17102 + 2 * (arfcn - 512);
freq10_dl = freq10_ul + 950;
} else if (arfcn >= 259 && arfcn <= 293) {
/* GSM 450 */
freq10_ul = 4506 + 2 * (arfcn - 259);
freq10_dl = freq10_ul + 100;
} else if (arfcn >= 306 && arfcn <= 340) {
/* GSM 480 */
freq10_ul = 4790 + 2 * (arfcn - 306);
freq10_dl = freq10_ul + 100;
} else if (arfcn >= 350 && arfcn <= 425) {
/* GSM 810 */
freq10_ul = 8060 + 2 * (arfcn - 350);
freq10_dl = freq10_ul + 450;
} else if (arfcn >= 438 && arfcn <= 511) {
/* GSM 750 */
freq10_ul = 7472 + 2 * (arfcn - 438);
freq10_dl = freq10_ul + 300;
} else
return 0xffff;
if (uplink)
return freq10_ul;
else
return freq10_dl;
}
void gsm_fn2gsmtime(struct gsm_time *time, uint32_t fn)
{
time->fn = fn;
time->t1 = time->fn / (26*51);
time->t2 = time->fn % 26;
time->t3 = time->fn % 51;
time->tc = (time->fn / 51) % 8;
}
uint32_t gsm_gsmtime2fn(struct gsm_time *time)
{
/* TS 05.02 Chapter 4.3.3 TDMA frame number */
return (51 * ((time->t3 - time->t2 + 26) % 26) + time->t3 + (26 * 51 * time->t1));
}
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