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hodec2: clarify current and target rxlev per candidate 

Store the rxlev of the current lchan and the target BTS in the
ho_candidate, to clarify the code.

No functional change, cosmetically prepare for
I2704899c85c35dfd4eba43468452483f40016ca2.

Change-Id: Ie6c165e17bb3c99eebc967a6bb02529db8bdfc98
This commit is contained in:
Neels Hofmeyr 2020-12-24 12:02:26 +01:00
parent 90175e6987
commit 0c01ab6cbb
1 changed files with 51 additions and 48 deletions
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99
src/osmo-bsc/handover_decision_2.c
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@ -104,7 +104,8 @@ struct ho_candidate {
struct gsm_bts *bts; /* target BTS in local BSS */
const struct gsm0808_cell_id_list2 *cil; /* target cells in remote BSS */
uint8_t requirements; /* what is fulfilled */
int avg; /* average RX level */
int rxlev_current;
int rxlev_target;
};
enum ho_reason {
@ -236,6 +237,15 @@ static struct gsm_meas_rep_cell *cell_in_rep(struct gsm_meas_rep *mr, uint16_t a
return NULL;
}
static int current_rxlev(struct gsm_lchan *lchan)
{
struct gsm_bts *bts = lchan->ts->trx->bts;
return get_meas_rep_avg(lchan,
ho_get_hodec2_full_tdma(bts->ho) ?
MEAS_REP_DL_RXLEV_FULL : MEAS_REP_DL_RXLEV_SUB,
ho_get_hodec2_rxlev_avg_win(bts->ho));
}
/* obtain averaged rxlev for given neighbor */
static int neigh_meas_avg(struct neigh_meas_proc *nmp, int window)
{
@ -814,7 +824,7 @@ static int trigger_ho(struct ho_candidate *c, uint8_t requirements)
/* verbosely log about a handover candidate */
static inline void debug_candidate(struct ho_candidate *candidate,
int8_t rxlev, int tchf_count, int tchh_count)
int tchf_count, int tchh_count)
{
struct gsm_lchan *lchan = candidate->lchan;
@ -831,25 +841,25 @@ static inline void debug_candidate(struct ho_candidate *candidate,
if (candidate->cil)
LOGPHOLCHANTOREMOTE(lchan, candidate->cil, LOGL_DEBUG,
"RX level %d dBm -> %d dBm\n",
rxlev2dbm(rxlev), rxlev2dbm(candidate->avg));
rxlev2dbm(candidate->rxlev_current), rxlev2dbm(candidate->rxlev_target));
if (candidate->bts == lchan->ts->trx->bts)
LOGPHOLCHANTOBTS(lchan, candidate->bts, LOGL_DEBUG,
"RX level %d dBm; "
HO_CANDIDATE_FMT(f, F) "; " HO_CANDIDATE_FMT(h, H) "\n",
rxlev2dbm(candidate->avg),
rxlev2dbm(candidate->rxlev_current),
HO_CANDIDATE_ARGS(f, F), HO_CANDIDATE_ARGS(h, H));
else if (candidate->bts)
LOGPHOLCHANTOBTS(lchan, candidate->bts, LOGL_DEBUG,
"RX level %d dBm -> %d dBm; "
HO_CANDIDATE_FMT(f, F) "; " HO_CANDIDATE_FMT(h, H) "\n",
rxlev2dbm(rxlev), rxlev2dbm(candidate->avg),
rxlev2dbm(candidate->rxlev_current), rxlev2dbm(candidate->rxlev_target),
HO_CANDIDATE_ARGS(f, F), HO_CANDIDATE_ARGS(h, H));
}
/* add candidate for re-assignment within the current cell */
static void collect_assignment_candidate(struct gsm_lchan *lchan, struct ho_candidate *clist,
unsigned int *candidates, int av_rxlev)
unsigned int *candidates, int rxlev_current)
{
struct gsm_bts *bts = lchan->ts->trx->bts;
int tchf_count, tchh_count;
@ -862,10 +872,11 @@ static void collect_assignment_candidate(struct gsm_lchan *lchan, struct ho_cand
.lchan = lchan,
.bts = bts,
.requirements = check_requirements(lchan, bts, tchf_count, tchh_count),
.avg = av_rxlev,
.rxlev_current = rxlev_current,
.rxlev_target = rxlev_current, /* same cell, same rxlev */
};
debug_candidate(&c, 0, tchf_count, tchh_count);
debug_candidate(&c, tchf_count, tchh_count);
if (!c.requirements)
return;
@ -877,7 +888,7 @@ static void collect_assignment_candidate(struct gsm_lchan *lchan, struct ho_cand
/* add candidates for handover to all neighbor cells */
static void collect_handover_candidate(struct gsm_lchan *lchan, struct neigh_meas_proc *nmp,
struct ho_candidate *clist, unsigned int *candidates,
bool include_weaker_rxlev, int av_rxlev,
bool include_weaker_rxlev, int rxlev_current,
int *neighbors_count)
{
struct gsm_bts *bts = lchan->ts->trx->bts;
@ -890,7 +901,6 @@ static void collect_handover_candidate(struct gsm_lchan *lchan, struct neigh_mea
.arfcn = nmp->arfcn,
.bsic = nmp->bsic,
};
int avg;
struct ho_candidate c;
int min_rxlev;
struct handover_cfg *neigh_cfg;
@ -929,27 +939,25 @@ static void collect_handover_candidate(struct gsm_lchan *lchan, struct neigh_mea
* instead assume the local BTS' config to apply. */
neigh_cfg = (neighbor_bts ? : bts)->ho;
/* calculate average rxlev for this cell over the window */
avg = neigh_meas_avg(nmp, ho_get_hodec2_rxlev_neigh_avg_win(bts->ho));
c = (struct ho_candidate){
.lchan = lchan,
.avg = avg,
.nik = ni,
.bts = neighbor_bts,
.cil = neighbor_cil,
.rxlev_current = rxlev_current,
.rxlev_target = neigh_meas_avg(nmp, ho_get_hodec2_rxlev_neigh_avg_win(bts->ho)),
};
/* Heed rxlev hysteresis only if the RXLEV/RXQUAL/TA levels of the MS aren't critically bad and
* we're just looking for an improvement. If levels are critical, we desperately need a handover
* and thus skip the hysteresis check. */
if (!include_weaker_rxlev) {
unsigned int pwr_hyst = ho_get_hodec2_pwr_hysteresis(bts->ho);
if (avg <= (av_rxlev + pwr_hyst)) {
int pwr_hyst = ho_get_hodec2_pwr_hysteresis(bts->ho);
if ((c.rxlev_target - c.rxlev_current) <= pwr_hyst) {
LOGPHOCAND(&c, LOGL_DEBUG,
"Not a candidate, because RX level (%d dBm) is lower"
" or equal than current RX level (%d dBm) + hysteresis (%d)\n",
rxlev2dbm(avg), rxlev2dbm(av_rxlev), pwr_hyst);
rxlev2dbm(c.rxlev_target), rxlev2dbm(c.rxlev_current), pwr_hyst);
return;
}
}
@ -957,11 +965,11 @@ static void collect_handover_candidate(struct gsm_lchan *lchan, struct neigh_mea
/* if the minimum level is not reached.
* In case of a remote-BSS, use the current BTS' configuration. */
min_rxlev = ho_get_hodec2_min_rxlev(neigh_cfg);
if (rxlev2dbm(avg) < min_rxlev) {
if (rxlev2dbm(c.rxlev_target) < min_rxlev) {
LOGPHOCAND(&c, LOGL_DEBUG,
"Not a candidate, because RX level (%d dBm) is lower"
" than the minimum required RX level (%d dBm)\n",
rxlev2dbm(avg), min_rxlev);
rxlev2dbm(c.rxlev_target), min_rxlev);
return;
}
@ -973,7 +981,7 @@ static void collect_handover_candidate(struct gsm_lchan *lchan, struct neigh_mea
} else
c.requirements = check_requirements_remote_bss(lchan, neighbor_cil);
debug_candidate(&c, av_rxlev, tchf_count, tchh_count);
debug_candidate(&c, tchf_count, tchh_count);
if (!c.requirements)
return;
@ -984,30 +992,25 @@ static void collect_handover_candidate(struct gsm_lchan *lchan, struct neigh_mea
static void collect_candidates_for_lchan(struct gsm_lchan *lchan,
struct ho_candidate *clist, unsigned int *candidates,
int *_av_rxlev, bool include_weaker_rxlev)
int *_rxlev_current, bool include_weaker_rxlev)
{
struct gsm_bts *bts = lchan->ts->trx->bts;
int av_rxlev;
int rxlev_current;
bool assignment;
bool handover;
int neighbors_count = 0;
unsigned int rxlev_avg_win = ho_get_hodec2_rxlev_avg_win(bts->ho);
OSMO_ASSERT(candidates);
/* calculate average rxlev for this cell over the window */
av_rxlev = get_meas_rep_avg(lchan,
ho_get_hodec2_full_tdma(bts->ho) ?
MEAS_REP_DL_RXLEV_FULL : MEAS_REP_DL_RXLEV_SUB,
rxlev_avg_win);
if (_av_rxlev)
*_av_rxlev = av_rxlev;
rxlev_current = current_rxlev(lchan);
if (_rxlev_current)
*_rxlev_current = rxlev_current;
/* in case there is no measurement report (yet) */
if (av_rxlev < 0) {
if (rxlev_current < 0) {
LOGPHOLCHAN(lchan, LOGL_DEBUG, "Not collecting candidates, not enough measurements"
" (got %d, want %u)\n",
lchan->meas_rep_count, rxlev_avg_win);
lchan->meas_rep_count, ho_get_hodec2_rxlev_avg_win(bts->ho));
return;
}
@ -1015,14 +1018,14 @@ static void collect_candidates_for_lchan(struct gsm_lchan *lchan,
handover = ho_get_ho_active(bts->ho);
if (assignment)
collect_assignment_candidate(lchan, clist, candidates, av_rxlev);
collect_assignment_candidate(lchan, clist, candidates, rxlev_current);
if (handover) {
int i;
for (i = 0; i < ARRAY_SIZE(lchan->neigh_meas); i++) {
collect_handover_candidate(lchan, &lchan->neigh_meas[i],
clist, candidates,
include_weaker_rxlev, av_rxlev, &neighbors_count);
include_weaker_rxlev, rxlev_current, &neighbors_count);
}
}
}
@ -1083,7 +1086,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
struct gsm_bts *bts = lchan->ts->trx->bts;
int ahs = (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR
&& lchan->type == GSM_LCHAN_TCH_H);
int av_rxlev;
int rxlev_current;
struct ho_candidate clist[1 + ARRAY_SIZE(lchan->neigh_meas)];
unsigned int candidates = 0;
int i;
@ -1099,7 +1102,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
return 0;
}
collect_candidates_for_lchan(lchan, clist, &candidates, &av_rxlev, include_weaker_rxlev);
collect_candidates_for_lchan(lchan, clist, &candidates, &rxlev_current, include_weaker_rxlev);
/* If assignment is disabled and no neighbor cell report exists, or no neighbor cell qualifies,
* we may not even have any candidates. */
@ -1121,7 +1124,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
if (!clist[i].bts)
continue;
better = clist[i].avg - av_rxlev;
better = clist[i].rxlev_target - clist[i].rxlev_current;
/* Apply AFS bias? */
afs_bias = 0;
if (ahs && (clist[i].requirements & REQUIREMENT_B_TCHF))
@ -1137,7 +1140,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
/* perform handover, if there is a candidate */
if (best_cand) {
LOGPHOCAND(best_cand, LOGL_INFO, "Best candidate, RX level %d%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
best_applied_afs_bias ? " (applied AHS -> AFS rxlev bias)" : "");
return trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_B_MASK);
}
@ -1154,7 +1157,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
if (!clist[i].bts)
continue;
better = clist[i].avg - av_rxlev;
better = clist[i].rxlev_target - clist[i].rxlev_current;
/* Apply AFS bias? */
afs_bias = 0;
if (ahs && (clist[i].requirements & REQUIREMENT_C_TCHF))
@ -1170,7 +1173,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
/* perform handover, if there is a candidate */
if (best_cand) {
LOGPHOCAND(best_cand, LOGL_INFO, "Best candidate, RX level %d%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
best_applied_afs_bias? " (applied AHS -> AFS rxlev bias)" : "");
return trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_C_MASK);
}
@ -1191,7 +1194,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
if (!(clist[i].requirements & REQUIREMENT_A_MASK))
continue;
better = clist[i].avg - av_rxlev;
better = clist[i].rxlev_target - clist[i].rxlev_current;
/* Apply AFS bias?
* (never to remote-BSS neighbors, since we will not change the lchan type for those.) */
afs_bias = 0;
@ -1209,7 +1212,7 @@ static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_r
/* perform handover, if there is a candidate */
if (best_cand) {
LOGPHOCAND(best_cand, LOGL_INFO, "Best candidate: RX level %d%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
best_applied_afs_bias ? " (applied AHS -> AFS rxlev bias)" : "");
return trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_A_MASK);
}
@ -1475,7 +1478,7 @@ static struct ho_candidate *pick_best_candidate(int *applied_afs_bias,
&& (intra_cell && upgrade_to_tch_f))
continue;
avg_rxlev = c->avg;
avg_rxlev = c->rxlev_target;
/* improve AHS */
if (upgrade_to_tch_f)
@ -1639,7 +1642,7 @@ static int bts_resolve_congestion(struct gsm_bts *bts, int tchf_congestion, int
LOGPHOCAND(&clist[i], LOGL_DEBUG, "#%d: req={TCH/F:" REQUIREMENTS_FMT ", TCH/H:" REQUIREMENTS_FMT "} avg-rxlev=%d dBm\n",
i, REQUIREMENTS_ARGS(clist[i].requirements, F),
REQUIREMENTS_ARGS(clist[i].requirements, H),
rxlev2dbm(clist[i].avg));
rxlev2dbm(clist[i].rxlev_target));
}
}
@ -1662,7 +1665,7 @@ next_b1:
if (best_cand) {
any_ho = 1;
LOGPHOCAND(best_cand, LOGL_DEBUG, "Best candidate: RX level %d%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
is_improved ? " (applied AHS->AFS bias)" : "");
trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_B_MASK);
#if 0
@ -1703,7 +1706,7 @@ next_b2:
if (best_cand) {
any_ho = 1;
LOGPHOCAND(best_cand, LOGL_INFO, "Worst candidate: RX level %d from TCH/H -> TCH/F%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
is_improved ? " (applied AHS -> AFS rxlev bias)" : "");
trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_B_MASK);
#if 0
@ -1738,7 +1741,7 @@ next_c1:
if (best_cand) {
any_ho = 1;
LOGPHOCAND(best_cand, LOGL_INFO, "Best candidate: RX level %d%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
is_improved ? " (applied AHS -> AFS rxlev bias)" : "");
trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_C_MASK);
#if 0
@ -1781,7 +1784,7 @@ next_c2:
if (best_cand) {
any_ho = 1;
LOGPHOCAND(best_cand, LOGL_INFO, "Worst candidate: RX level %d from TCH/H -> TCH/F%s\n",
rxlev2dbm(best_cand->avg),
rxlev2dbm(best_cand->rxlev_target),
is_improved ? " (applied AHS -> AFS rxlev bias)" : "");
trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_C_MASK);
#if 0