--- /dev/null
+/*
+ * (C) 2010 by Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * 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.
+ *
+ */
+
+todo: cell selection and reselection criteria
+todo: path loss
+todo: downlink signal failure
+
+/* allocate a 05.08 event message */
+struct msgb *gsm58_msgb_alloc(int msg_type)
+{
+ struct msgb *msg;
+ struct gsm58_msg *gm;
+
+ msg = msgb_alloc_headroom(GSM58_ALLOC_SIZE, GSM58_ALLOC_HEADROOM,
+ "GSM 05.08");
+ if (!msg)
+ return NULL;
+
+ gm = (struct gsm58_msg *)msgb_put(msg, sizeof(*gm));
+ gm->msg_type = msg_type;
+ return msg;
+}
+
+/* select first/next frequency */
+static int gsm58_select_bcch(struct osmocom_ms *ms)
+{
+ struct gsm_support *s = &ms->support;
+ struct gsm58_selproc *sp = &ms->selproc;
+ int i, j = 0;
+
+next:
+ for (i = 0, i < 1024, i++) {
+ if ((sp->ba[i >> 3] & (1 << (i & 7)))) {
+ if (j == sp->cur_freq)
+ break;
+ j++;
+ }
+ }
+ if (i == 1024) {
+ struct msgb *nmsg;
+
+ DEBUGP(DRR, "Cycled through all %d frequencies in list.\n", j);
+ nmsg = gsm322_msgb_alloc(GSM322_EVENT_NO_CELL_F);
+ if (!nmsg)
+ return -ENOMEM;
+ gsm322_sendmsg(ms, nmsg);
+ }
+
+ /* if frequency not supported */
+ if (!(s->freq_map[i >> 3] & (1 << (i & 7)))) {
+ DEBUGP(DRR, "Frequency %d in list, but not supported.\n", i);
+ sp->cur_freq++;
+ goto next;
+ }
+
+ /* set current BCCH frequency */
+ sp->arfcn = i;
+ DEBUGP(DRR, "Frequency %d selected, wait for sync.\n", sp->arfcn);
+ tx_ph_bcch_req(ms, sp->arfcn);
+
+ /* start timer for synchronizanation */
+ gsm58_timer_start(sp, 0, 500000);
+
+ sp->mode = GSM58_MODE_SYNC;
+
+ return 0;
+}
+
+
+/* start normal cell selection: search any channel for given PLMN */
+static int gsm58_start_normal_sel(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_selproc *sp = &ms->selproc;
+ struct gsm_support *s = &ms->support;
+ struct gsm58_msg *gm = msgb->data;
+
+ /* reset process */
+ memset(sp, 0, sizeof(*sp));
+
+ /* use all frequencies from supported frequency map */
+ memcpy(sp->ba, s->freq_map, sizeof(sp->ba));
+
+ /* limit process to given PLMN */
+ sp->mcc = gm->mcc;
+ sp->mnc = gm->mnc;
+
+ /* select first channel */
+ gsm58_select_bcch(ms);
+}
+
+/* start stored cell selection: search given channels for given PLMN */
+static int gsm58_start_stored_sel(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_selproc *sp = &ms->selproc;
+ struct gsm_support *s = &ms->support;
+ struct gsm58_msg *gm = msgb->data;
+
+ /* reset process */
+ memset(sp, 0, sizeof(*sp));
+
+ /* use all frequencies from given frequency map */
+ memcpy(sp->ba, sp->ba, sizeof(sp->ba));
+
+ /* limit process to given PLMN */
+ sp->mcc = gm->mcc;
+ sp->mnc = gm->mnc;
+
+ /* select first channel */
+ gsm58_select_bcch(ms);
+}
+
+/* start any cell selection: search any channel for any PLMN */
+static int gsm58_start_any_sel(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_selproc *sp = &ms->selproc;
+ struct gsm_support *s = &ms->support;
+ struct gsm58_msg *gm = msgb->data;
+
+ /* reset process */
+ memset(sp, 0, sizeof(*sp));
+
+ /* allow any cell not barred */
+ sp->any = 1;
+
+ /* use all frequencies from supported frequency map */
+ memcpy(sp->ba, s->freq_map, sizeof(sp->ba));
+
+ /* select first channel */
+ gsm58_select_bcch(ms);
+}
+
+/* timeout while selecting BCCH */
+static int gsm58_sel_timeout(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_selproc *sp = &ms->selproc;
+
+ switch(sp->mode) {
+ case GSM58_MODE_SYNC:
+ /* if no sync is received from radio withing sync time */
+ DEBUGP(DRR, "Syncronization failed, selecting next frq.\n");
+ break;
+ case GSM58_MODE_READ:
+ /* timeout while reading BCCH */
+ DEBUGP(DRR, "BCC reading failed, selecting next frq.\n");
+ break;
+ default:
+ DEBUGP(DRR, "Timeout in wrong mode, please fix!\n");
+ }
+
+ sp->cur_freq++;
+ gsm58_select_bcch(ms);
+
+ return 0;
+}
+
+/* we are synchronized to selecting BCCH */
+static int gsm58_sel_sync(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_selproc *sp = &ms->selproc;
+ struct gsm58_msg *gm = (struct gsm58_msg *)msgb->data;
+
+ /* if we got a sync while already selecting a new frequency */
+ if (gm->arfcn != sp->arfcn) {
+ DEBUGP(DRR, "Requested frq %d, but synced to %d, ignoring.\n"
+ sp->arfcn, gm->arfcn);
+ return 0;
+ }
+
+ DEBUGP(DRR, "Synced to %d, waiting for relevant data.\n", sp->arfcn);
+
+ /* set timer for reading BCCH */
+ gsm58_timer_start(sp, 4, 0); // TODO: timer depends on BCCH configur.
+
+ /* reset sysinfo and wait for relevant data */
+ gsm_sysinfo_init(ms);
+ sp->mode = GSM58_MODE_READ;
+
+ return 0;
+}
+
+/* we are getting sysinfo from BCCH */
+static int gsm58_sel_sysinfo(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_selproc *sp = &ms->selproc;
+ struct gsm58_msg *gm = (struct gsm58_msg *)msgb->data;
+ struct msgb *nmsg;
+ int barred = 0, i;
+
+ /* ignore system info, if not synced */
+ if (sp->mode != GSM58_MODE_DATA && sp->mode != GSM58_MODE_CAMP)
+ return 0;
+
+ /* check if cell is barred for us */
+ if (!subscr->barred_access && s->cell_barred)
+ barred = 1;
+ if (sp->any) {
+ if (s->class_barr[10])
+ barred = 1;
+ } else {
+ for (i = 0, i <= 15, i++)
+ if (subscr->class_access[i] && !s->class_barr[i])
+ break;
+ if (i > 15)
+ barred = 1;
+ }
+
+
+ /* cell has become barred */
+ if (sp->mode == GSM58_MODE_CAMP) {
+ if (barred) {
+ DEBUGP(DRR, "Cell has become barred, starting "
+ "reselection.\n");
+
+ sp->mode = GSM58_MODE_IDLE;
+
+ nmsg = gsm322_msgb_alloc(GSM322_EVENT_CELL_RESEL);
+ if (!nmsg)
+ return -ENOMEM;
+ gsm322_sendmsg(ms, nmsg);
+
+ return 0;
+ }
+
+ return 0;
+ }
+
+ /* can't use barred cell */
+ if (barred) {
+ DEBUGP(DRR, "Selected cell is barred, select next.\n");
+ gsm58_timer_stop(sp);
+ sp->cur_freq++;
+ gsm58_select_bcch(ms);
+
+ return 0;
+ }
+
+ /* if PLMN not yet indicated */
+ if (!s->mcc && !s->mnc)
+ return 0;
+
+ // todo: what else do we need until we can camp?
+
+ /* all relevant informations received */
+ gsm58_timer_stop(sp);
+ sp->mode = GSM58_MODE_CAMP;
+
+ DEBUGP(DRR, "Cell with freq %d, mcc = %d, mnc = %d selected.\n",
+ sp->arfcn, s->mcc, s->mnc);
+
+ nmsg = gsm322_msgb_alloc(GSM322_EVENT_CELL_FOUND);
+ if (!nmsg)
+ return -ENOMEM;
+ gsm322_sendmsg(ms, nmsg);
+
+ return 0;
+}
+
+/* receive events for GSM 05.08 processes */
+static int gsm58_event(struct osmocom_ms *ms, struct msgb *msg)
+{
+ struct gsm58_msg *gm = (struct gsm58_msg *)msgb->data;
+ int msg_type = gm->msg_type;
+
+ DEBUGP(DRR, "(ms %s) Message '%s' for link control "
+ "%s\n", ms->name, gsm58_event_names[msg_type],
+ plmn_a_state_names[plmn->state]);
+
+ switch(msg_type) {
+ case GSM58_EVENT_START_NORMAL:
+ gsm58_start_normal_sel(ms, msg);
+ break;
+ case GSM58_EVENT_START_STORED:
+ gsm58_start_stored_sel(ms, msg);
+ break;
+ case GSM58_EVENT_START_ANY:
+ gsm58_start_any_sel(ms, msg);
+ break;
+ case GSM58_EVENT_TIMEOUT:
+ gsm58_sel_timeout(ms, msg);
+ break;
+ case GSM58_EVENT_SYNC:
+ gsm58_sel_sync(ms, msg);
+ break;
+ case GSM58_EVENT_SYSINFO:
+ gsm58_sel_sysinfo(ms, msg);
+ break;
+ default:
+ DEBUGP(DRR, "Message unhandled.\n");
+ }
+
+ free_msgb(msg);
+
+ return 0;
+}
+
+
+static void gsm58_timer_timeout(void *arg)
+{
+ struct gsm322_58_selproc *sp = arg;
+ struct msgb *nmsg;
+
+ /* indicate BCCH selection T timeout */
+ nmsg = gsm58_msgb_alloc(GSM58_EVENT_TIMEOUT);
+ if (!nmsg)
+ return -ENOMEM;
+ gsm58_sendmsg(ms, nmsg);
+}
+
+static void gsm58_timer_start(struct gsm58_selproc *sp, int secs, int micro)
+{
+ DEBUGP(DRR, "starting FREQUENCY search timer\n");
+ sp->timer.cb = gsm58_timer_timeout;
+ sp->timer.data = sp;
+ bsc_schedule_timer(&sp->timer, secs, micro);
+}
+
+static void gsm58_timer_stop(struct gsm58_selproc *plmn)
+{
+ if (timer_pending(&sp->timer)) {
+ DEBUGP(DRR, "stopping pending timer\n");
+ bsc_del_timer(&sp->timer);
+ }
+}
--- /dev/null
+/*
+ * (C) 2010 by Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * 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.
+ *
+ */
+
+/* GSM 05.08 events */
+#define GSM58_EVENT_START_NORMAL 1
+#define GSM58_EVENT_START_STORED 2
+#define GSM58_EVENT_START_ANY 3
+#define GSM58_EVENT_TIMEOUT 4
+#define GSM58_EVENT_SYNC 5
+#define GSM58_EVENT_SYSINFO 6
+#define GSM58_EVENT_ 7
+#define GSM58_EVENT_ 8
+#define GSM58_EVENT_ 9
+#define GSM58_EVENT_ 10
+#define GSM58_EVENT_ 11
+#define GSM58_EVENT_ 12
+
+case GSM58_EVENT_START_NORMAL_SEL:
+gsm58_start_normal_sel(ms, msg);
+break;
+case GSM58_EVENT_START_STORED_SEL:
+gsm58_start_stored_sel(ms, msg);
+break;
+case GSM58_EVENT_START_ANY_SEL:
+gsm58_start_any_sel(ms, msg);
+break;
+case GSM58_EVENT_TIMEOUT:
+gsm58_sel_timeout(ms, msg);
+break;
+case GSM58_EVENT_SYNC:
+gsm58_sel_sync(ms, msg);
+break;
+case GSM58_EVENT_SYSINFO:
+gsm58_sel_sysinfo(ms, msg);
+break;
+
+enum {
+ GSM58_MODE_IDLE,
+ GSM58_MODE_SYNC,
+ GSM58_MODE_READ,
+ GSM58_MODE_CAMP
+};
+
+/* GSM 05.08 message */
+struct gsm58_msg {
+ int msg_type;
+ uint16_t mcc;
+ uint16_t mnc;
+ uint8_t ba[128];
+ uint16_t arfcn;
+};
+
+#define GSM58_ALLOC_SIZE sizeof(struct gsm58_mgs)
+#define GSM58_ALLOC_HEADROOM 0
+
+/* GSM 05.08 selection process */
+struct gsm58_selproc {
+ int mode;
+ uint16_t mcc;
+ uint16_t mnc;
+ uint8_t ba[128];
+ uint16_t cur_freq; /* index */
+ uint16_t arfcn; /* channel number */
+};
+
+
projects / osmocom-bb.git / commitdiff