osmo-bts/src/osmo-bts-sysmo/utils.c

88 lines
2.5 KiB
C

/*
* Helper utilities that are used in OML
*
* (C) 2011 by Harald Welte <laforge@gnumonks.org>
* (C) 2013 by Holger Hans Peter Freyther
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 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 Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "utils.h"
#include <osmo-bts/bts.h>
#include "femtobts.h"
static int band_osmo2femto(enum gsm_band osmo_band)
{
switch (osmo_band) {
case GSM_BAND_850:
return GsmL1_FreqBand_850;
case GSM_BAND_900:
return GsmL1_FreqBand_900;
case GSM_BAND_1800:
return GsmL1_FreqBand_1800;
case GSM_BAND_1900:
return GsmL1_FreqBand_1900;
default:
return -1;
}
}
/**
* Select the band that matches the ARFCN. In general the ARFCNs
* for GSM1800 and GSM1900 overlap and one needs to specify the
* rightband. When moving between GSM900/GSM1800 and GSM850/1900
* modifying the BTS configuration is a bit annoying. The auto-band
* configuration allows to ease with this transition.
*/
int sysmobts_select_femto_band(struct gsm_bts *bts, uint16_t arfcn)
{
enum gsm_band band;
struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
if (!btsb->auto_band)
return band_osmo2femto(bts->band);
/*
* We need to check what will happen now.
*/
band = gsm_arfcn2band(arfcn);
/* if we are already on the right band return */
if (band == bts->band)
return band_osmo2femto(bts->band);
/* Check if it is GSM1800/GSM1900 */
if (band == GSM_BAND_1800 && bts->band == GSM_BAND_1900)
return band_osmo2femto(bts->band);
/*
* Now to the actual autobauding. We just want DCS/DCS and
* PCS/PCS for PCS we check for 850/1800 though
*/
if ((band == GSM_BAND_900 && bts->band == GSM_BAND_1800)
|| (band == GSM_BAND_1800 && bts->band == GSM_BAND_900)
|| (band == GSM_BAND_850 && bts->band == GSM_BAND_1900))
return band_osmo2femto(band);
if (band == GSM_BAND_1800 && bts->band == GSM_BAND_850)
return band_osmo2femto(GSM_BAND_1900);
/* give up */
return -1;
}