| 447 |
447 |
return 0;
|
| 448 |
448 |
}
|
| 449 |
449 |
|
| 450 |
|
/* compatibility check for codecs.
|
| 451 |
|
* if so, the candidates for full rate and half rate are selected */
|
| 452 |
|
switch (lchan->tch_mode) {
|
| 453 |
|
case GSM48_CMODE_SPEECH_V1:
|
| 454 |
|
switch (lchan->type) {
|
| 455 |
|
case GSM_LCHAN_TCH_F: /* mandatory */
|
| 456 |
|
requirement |= REQUIREMENT_A_TCHF;
|
| 457 |
|
break;
|
| 458 |
|
case GSM_LCHAN_TCH_H:
|
| 459 |
|
if (!bts->codec.hr) {
|
| 460 |
|
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG,
|
| 461 |
|
"tch_mode='%s' type='%s' not supported\n",
|
| 462 |
|
get_value_string(gsm48_chan_mode_names,
|
| 463 |
|
lchan->tch_mode),
|
| 464 |
|
gsm_lchant_name(lchan->type));
|
| 465 |
|
break;
|
| 466 |
|
}
|
| 467 |
|
if (codec_type_is_supported(lchan->conn, GSM0808_SCT_HR1))
|
| 468 |
|
requirement |= REQUIREMENT_A_TCHH;
|
| 469 |
|
break;
|
| 470 |
|
default:
|
| 471 |
|
LOGPHOLCHAN(lchan, LOGL_ERROR, "Unexpected channel type: neither TCH/F nor TCH/H for %s\n",
|
| 472 |
|
get_value_string(gsm48_chan_mode_names, lchan->tch_mode));
|
| 473 |
|
return 0;
|
| 474 |
|
}
|
| 475 |
|
break;
|
| 476 |
|
case GSM48_CMODE_SPEECH_EFR:
|
| 477 |
|
if (!bts->codec.efr) {
|
| 478 |
|
LOGPHOBTS(bts, LOGL_DEBUG, "EFR not supported\n");
|
| 479 |
|
break;
|
| 480 |
|
}
|
| 481 |
|
if (codec_type_is_supported(lchan->conn, GSM0808_SCT_FR2))
|
| 482 |
|
requirement |= REQUIREMENT_A_TCHF;
|
| 483 |
|
break;
|
| 484 |
|
case GSM48_CMODE_SPEECH_AMR:
|
| 485 |
|
if (!bts->codec.amr) {
|
| 486 |
|
LOGPHOBTS(bts, LOGL_DEBUG, "AMR not supported\n");
|
| 487 |
|
break;
|
| 488 |
|
}
|
| 489 |
|
if (codec_type_is_supported(lchan->conn, GSM0808_SCT_FR3))
|
| 490 |
|
requirement |= REQUIREMENT_A_TCHF;
|
| 491 |
|
if (codec_type_is_supported(lchan->conn, GSM0808_SCT_HR3))
|
| 492 |
|
requirement |= REQUIREMENT_A_TCHH;
|
| 493 |
|
break;
|
| 494 |
|
default:
|
| 495 |
|
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "Not even considering: src is not a SPEECH mode lchan\n");
|
| 496 |
|
/* FIXME: should allow handover of non-speech lchans */
|
| 497 |
|
return 0;
|
|
450 |
/* To which TCH type and codec can we handover? Consider targets independently from the current lchan's TCH kind
|
|
451 |
* and codec, to support TCH/F <-> TCH/H handovers and those that switch the codec type. */
|
|
452 |
|
|
453 |
/* TCH/F target? */
|
|
454 |
if (tchf_count) {
|
|
455 |
/* TCH/F timeslots are available, and FR1 is always supported. Could also end up using EFR or AMR codecs. */
|
|
456 |
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "considering HO to TCH/F (%d available)\n", tchf_count);
|
|
457 |
requirement |= REQUIREMENT_A_TCHF;
|
|
458 |
} else {
|
|
459 |
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "not considering HO to TCH/F (0 available)\n");
|
| 498 |
460 |
}
|
|
461 |
/* If the EFR (FR2) codec is supported, we'd add requirement |= TCH/F. Since TCH/F is already always supported,
|
|
462 |
* there is no need to check for EFR here. */
|
| 499 |
463 |
|
| 500 |
|
/* no candidate, because new cell is incompatible */
|
| 501 |
|
if (!requirement) {
|
| 502 |
|
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "not a candidate, because codec of MS and BTS are incompatible\n");
|
| 503 |
|
return 0;
|
| 504 |
|
}
|
|
464 |
/* TCH/H target? */
|
|
465 |
if (tchh_count) {
|
|
466 |
/* TCH/H timeslots are available, check whether any half rate codec is supported. */
|
|
467 |
bool hr1_ms = codec_type_is_supported(lchan->conn, GSM0808_SCT_HR1);
|
|
468 |
bool hr1_bts = (bts->codec.hr != 0);
|
|
469 |
bool hr3_ms = codec_type_is_supported(lchan->conn, GSM0808_SCT_HR3);
|
|
470 |
bool hr3_bts = (bts->codec.amr != 0);
|
|
471 |
bool add_tchh = (hr1_ms && hr1_bts) || (hr3_ms && hr3_bts);
|
| 505 |
472 |
|
| 506 |
|
/* remove slot types that are not available */
|
| 507 |
|
if (!tchf_count && requirement & REQUIREMENT_A_TCHF) {
|
| 508 |
|
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG,
|
| 509 |
|
"removing TCH/F, since all TCH/F lchans are in use\n");
|
| 510 |
|
requirement &= ~(REQUIREMENT_A_TCHF);
|
| 511 |
|
}
|
| 512 |
|
if (!tchh_count && requirement & REQUIREMENT_A_TCHH) {
|
| 513 |
|
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG,
|
| 514 |
|
"removing TCH/H, since all TCH/H lchans are in use\n");
|
| 515 |
|
requirement &= ~(REQUIREMENT_A_TCHH);
|
|
473 |
if (add_tchh)
|
|
474 |
requirement |= REQUIREMENT_A_TCHH;
|
|
475 |
|
|
476 |
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "%s HO to TCH/H"
|
|
477 |
" (support by MS/BTS for HR1: %s/%s, HR3(AMR): %s/%s)\n",
|
|
478 |
add_tchh ? "considering" : "not considering",
|
|
479 |
hr1_ms ? "yes" : "no",
|
|
480 |
hr1_bts ? "yes" : "no",
|
|
481 |
hr3_ms ? "yes" : "no",
|
|
482 |
hr3_bts ? "yes" : "no");
|
|
483 |
} else {
|
|
484 |
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "not considering HO to TCH/H, none available\n");
|
| 516 |
485 |
}
|
| 517 |
486 |
|
|
487 |
/* no candidate, because new cell is incompatible */
|
| 518 |
488 |
if (!requirement) {
|
| 519 |
|
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG, "not a candidate, because no suitable slots available\n");
|
|
489 |
LOGPHOLCHANTOBTS(lchan, bts, LOGL_DEBUG,
|
|
490 |
"Not a candidate, no lchans matching codecs supported by both MS and BTS are available\n");
|
| 520 |
491 |
return 0;
|
| 521 |
492 |
}
|
| 522 |
493 |
|
| ... | ... | |
| 607 |
578 |
* free slots of the current cell _after_ handover/assignment */
|
| 608 |
579 |
count = bts_count_free_ts(current_bts,
|
| 609 |
580 |
(lchan->type == GSM_LCHAN_TCH_H) ?
|
| 610 |
|
GSM_PCHAN_TCH_H : GSM_PCHAN_TCH_F);
|
|
581 |
GSM_PCHAN_TCH_H : GSM_PCHAN_TCH_F);
|
|
582 |
|
| 611 |
583 |
if (requirement & REQUIREMENT_A_TCHF) {
|
| 612 |
584 |
if (tchf_count - 1 >= count + 1)
|
| 613 |
585 |
requirement |= REQUIREMENT_C_TCHF;
|
