hodec2: code dup / cosmetics
In handover_decision_2.c, instead of repeating a similar loop four times, put that loop in a function and parameterize it. Prepare for a fix of two problems in handover decision 2, see I2704899c85c35dfd4eba43468452483f40016ca2. Change-Id: I7c32d08e490a88a7f044b0a71dc4b07d748dd572
This commit is contained in:
Neels Hofmeyr
parent
23da99ddda
commit
d15d672427
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@ -24,6 +24,7 @@
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#include <stdbool.h>
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#include <errno.h>
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#include <limits.h>
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#include <osmocom/bsc/debug.h>
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#include <osmocom/bsc/gsm_data.h>
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@ -1379,10 +1380,22 @@ static unsigned int ts_usage_count(struct gsm_bts_trx_ts *ts)
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return count;
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}
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static bool is_intra_cell(const struct ho_candidate *c)
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{
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return c->bts && (c->lchan->ts->trx->bts == c->bts);
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}
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static bool is_upgrade_to_tchf(const struct ho_candidate *c, uint8_t for_requirement)
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{
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return c->lchan
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&& (c->lchan->type == GSM_LCHAN_TCH_H)
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&& ((c->requirements & for_requirement) & (REQUIREMENT_B_TCHF | REQUIREMENT_C_TCHF));
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}
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/* Given two candidates, pick the one that should rather be moved during handover.
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* Return the better candidate in out-parameters best_cand and best_avg_db.
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*/
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static void pick_better_lchan_to_move(bool want_highest_db,
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static bool pick_better_lchan_to_move(bool want_highest_db,
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struct ho_candidate **best_cand_p, unsigned int *best_avg_db_p,
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struct ho_candidate *other_cand, unsigned int other_avg_db)
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{
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@ -1400,7 +1413,7 @@ static void pick_better_lchan_to_move(bool want_highest_db,
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/* If both are dynamic, prefer one that completely (or to a higher degree) frees its timeslot. */
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if (lchan_is_on_dynamic_ts((*best_cand_p)->lchan)
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&& ts_usage_count((*best_cand_p)->lchan->ts) < ts_usage_count(other_cand->lchan->ts))
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return;
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return false;
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/* If both equally satisfy these preferences, it does not matter which one is picked.
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* Give slight preference to moving later dyn TS, so that a free dyn TS may group with following static
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* PDCH, though this depends on how the user configured the TS -- not harmful to do so anyway. */
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@ -1408,11 +1421,76 @@ static void pick_better_lchan_to_move(bool want_highest_db,
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}
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/* keep the same candidate. */
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return;
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return false;
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return_other:
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*best_cand_p = other_cand;
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*best_avg_db_p = other_avg_db;
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return true;
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}
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static struct ho_candidate *pick_best_candidate(int *applied_afs_bias,
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struct ho_candidate *clist, int clist_len,
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bool want_highest_db,
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bool omit_intra_cell_upgrade_to_tchf,
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bool only_intra_cell_upgrade_to_tchf,
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uint8_t for_requirement)
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{
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struct ho_candidate *result = NULL;
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unsigned int result_avg_rxlev;
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int result_afs_bias = 0;
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int i;
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if (applied_afs_bias)
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*applied_afs_bias = 0;
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result_avg_rxlev = want_highest_db ? 0 : INT_MAX;
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for (i = 0; i < clist_len; i++) {
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struct ho_candidate *c = &clist[i];
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bool intra_cell;
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bool upgrade_to_tch_f;
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int avg_rxlev;
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int afs_bias;
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/* For multiple passes of congestion resolution, already handovered candidates are marked by lchan =
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* NULL. (though at the time of writing, multiple passes of congestion resolution are DISABLED.) */
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if (!c->lchan)
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continue;
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/* Omit remote BSS */
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if (!c->bts)
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continue;
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if (!(c->requirements & for_requirement))
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continue;
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intra_cell = is_intra_cell(c);
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upgrade_to_tch_f = is_upgrade_to_tchf(c, for_requirement);
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if (only_intra_cell_upgrade_to_tchf
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&& !(intra_cell && upgrade_to_tch_f))
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continue;
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if (omit_intra_cell_upgrade_to_tchf
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&& (intra_cell && upgrade_to_tch_f))
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continue;
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avg_rxlev = c->avg;
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/* improve AHS */
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if (upgrade_to_tch_f)
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afs_bias = ho_get_hodec2_afs_bias_rxlev(c->bts->ho);
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else
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afs_bias = 0;
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avg_rxlev += afs_bias;
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if (pick_better_lchan_to_move(want_highest_db, &result, &result_avg_rxlev, c, avg_rxlev))
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result_afs_bias = afs_bias;
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}
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if (applied_afs_bias)
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*applied_afs_bias = result_afs_bias;
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return result;
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}
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/*
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@ -1472,10 +1550,7 @@ static int bts_resolve_congestion(struct gsm_bts *bts, int tchf_congestion, int
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int i, j;
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struct ho_candidate *clist;
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unsigned int candidates;
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struct ho_candidate *best_cand = NULL, *worst_cand = NULL;
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struct gsm_lchan *delete_lchan = NULL;
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unsigned int best_avg_db, worst_avg_db;
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int avg;
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struct ho_candidate *best_cand = NULL;
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int rc = 0;
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int any_ho = 0;
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int is_improved = 0;
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@ -1571,55 +1646,19 @@ static int bts_resolve_congestion(struct gsm_bts *bts, int tchf_congestion, int
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#if 0
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next_b1:
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#endif
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/* select best candidate that fulfills requirement B,
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* omit change from AHS to AFS */
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best_avg_db = 0;
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for (i = 0; i < candidates; i++) {
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/* delete subscriber that just have handovered */
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if (clist[i].lchan == delete_lchan)
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clist[i].lchan = NULL;
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/* omit all subscribers that are handovered */
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if (!clist[i].lchan)
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continue;
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/* Do not resolve congestion towards remote BSS, which would cause oscillation if the
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* remote BSS is also congested. */
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/* TODO: attempt inter-BSC HO if no local cells qualify, and rely on the remote BSS to
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* deny receiving the handover if it also considers itself congested. Maybe do that only
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* when the cell is absolutely full, i.e. not only min-free-slots. (x) */
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if (!clist[i].bts)
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continue;
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if (!(clist[i].requirements & REQUIREMENT_B_MASK))
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continue;
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/* omit assignment from AHS to AFS */
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if (clist[i].lchan->ts->trx->bts == clist[i].bts
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&& clist[i].lchan->type == GSM_LCHAN_TCH_H
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&& (clist[i].requirements & REQUIREMENT_B_TCHF))
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continue;
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/* omit candidates that will not solve/reduce congestion */
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if (clist[i].lchan->type == GSM_LCHAN_TCH_F
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&& tchf_congestion <= 0)
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continue;
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if (clist[i].lchan->type == GSM_LCHAN_TCH_H
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&& tchh_congestion <= 0)
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continue;
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avg = clist[i].avg;
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/* improve AHS */
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if (clist[i].lchan->tch_mode == GSM48_CMODE_SPEECH_AMR
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&& clist[i].lchan->type == GSM_LCHAN_TCH_H
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&& (clist[i].requirements & REQUIREMENT_B_TCHF)) {
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avg += ho_get_hodec2_afs_bias_rxlev(clist[i].bts->ho);
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is_improved = 1;
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} else
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is_improved = 0;
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LOGPHOCAND(&clist[i], LOGL_DEBUG, "candidate %d: avg=%d best_avg_db=%d\n",
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i, avg, best_avg_db);
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pick_better_lchan_to_move(true, &best_cand, &best_avg_db, &clist[i], avg);
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}
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/* perform handover, if there is a candidate */
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/* select best candidate that does not cause congestion in the target.
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* Do not resolve congestion towards remote BSS, which would cause oscillation if the remote BSS is also
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* congested.
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* Treating specially below: upgrading TCH/H to TCH/F within the same cell, so omit here.
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*/
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/* TODO: attempt inter-BSC HO if no local cells qualify, and rely on the remote BSS to
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* deny receiving the handover if it also considers itself congested. Maybe do that only
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* when the cell is absolutely full, i.e. not only min-free-slots. (x) */
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best_cand = pick_best_candidate(&is_improved, clist, candidates,
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/* want_highest_db */ true,
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/* omit_intra_cell_upgrade_to_tchf */ true,
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/* only_intra_cell_upgrade_to_tchf */ false,
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REQUIREMENT_B_MASK);
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if (best_cand) {
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any_ho = 1;
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LOGPHOCAND(best_cand, LOGL_DEBUG, "Best candidate: RX level %d%s\n",
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@ -1650,59 +1689,29 @@ next_b1:
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#if 0
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next_b2:
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#endif
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/* select worst candidate that fulfills requirement B,
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* select candidates that change from AHS to AFS only */
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if (tchh_congestion > 0) {
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/* since this will only check half rate channels, it will
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* only need to be checked, if tchh is congested */
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worst_avg_db = 999;
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for (i = 0; i < candidates; i++) {
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/* delete subscriber that just have handovered */
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if (clist[i].lchan == delete_lchan)
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clist[i].lchan = NULL;
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/* omit all subscribers that are handovered */
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if (!clist[i].lchan)
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continue;
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/* Do not resolve congestion towards remote BSS, which would cause oscillation if
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* the remote BSS is also congested. */
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/* TODO: see (x) above */
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if (!clist[i].bts)
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continue;
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if (!(clist[i].requirements & REQUIREMENT_B_MASK))
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continue;
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/* omit all but assignment from AHS to AFS */
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if (clist[i].lchan->ts->trx->bts != clist[i].bts
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|| clist[i].lchan->type != GSM_LCHAN_TCH_H
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|| !(clist[i].requirements & REQUIREMENT_B_TCHF))
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continue;
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avg = clist[i].avg;
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/* improve AHS */
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if (clist[i].lchan->tch_mode == GSM48_CMODE_SPEECH_AMR
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&& clist[i].lchan->type == GSM_LCHAN_TCH_H) {
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avg += ho_get_hodec2_afs_bias_rxlev(clist[i].bts->ho);
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is_improved = 1;
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} else
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is_improved = 0;
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pick_better_lchan_to_move(false, &worst_cand, &worst_avg_db, &clist[i], avg);
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}
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}
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/* perform handover, if there is a candidate */
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if (worst_cand) {
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/* For upgrading TCH/H to TCH/F within the same cell, we want to pick the *lowest* average rxlev: for staying
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* within the same cell, give the MS with the worst service more bandwidth. When staying within the same cell,
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* the target avg rxlev is identical to the source lchan rxlev, so it is fine to use the same avg rxlev value,
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* but simply pick the lowest one.
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* Upgrading TCH/H channels obviously only applies when TCH/H is actually congested. */
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if (tchh_congestion > 0)
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best_cand = pick_best_candidate(&is_improved, clist, candidates,
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/* want_highest_db */ false,
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/* omit_intra_cell_upgrade_to_tchf */ false,
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/* only_intra_cell_upgrade_to_tchf */ true,
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REQUIREMENT_B_MASK);
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if (best_cand) {
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any_ho = 1;
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LOGPHOCAND(worst_cand, LOGL_INFO, "Worst candidate: RX level %d from TCH/H -> TCH/F%s\n",
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rxlev2dbm(worst_cand->avg),
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LOGPHOCAND(best_cand, LOGL_INFO, "Worst candidate: RX level %d from TCH/H -> TCH/F%s\n",
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rxlev2dbm(best_cand->avg),
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is_improved ? " (applied AHS -> AFS rxlev bias)" : "");
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trigger_ho(worst_cand, worst_cand->requirements & REQUIREMENT_B_MASK);
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trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_B_MASK);
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#if 0
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/* if there is still congestion, mark lchan as deleted
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* and redo this process */
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tchh_congestion--;
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if (tchh_congestion > 0) {
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delete_lchan = worst_cand->lchan;
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delete_lchan = best_cand->lchan;
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best_cand = NULL;
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goto next_b2;
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}
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@ -1718,51 +1727,14 @@ next_b2:
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#if 0
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next_c1:
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#endif
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/* select best candidate that fulfills requirement C,
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* omit change from AHS to AFS */
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best_avg_db = 0;
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for (i = 0; i < candidates; i++) {
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/* delete subscriber that just have handovered */
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if (clist[i].lchan == delete_lchan)
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clist[i].lchan = NULL;
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/* omit all subscribers that are handovered */
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if (!clist[i].lchan)
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continue;
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/* Do not resolve congestion towards remote BSS, which would cause oscillation if
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* the remote BSS is also congested. */
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/* TODO: see (x) above */
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if (!clist[i].bts)
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continue;
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if (!(clist[i].requirements & REQUIREMENT_C_MASK))
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continue;
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/* omit assignment from AHS to AFS */
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if (clist[i].lchan->ts->trx->bts == clist[i].bts
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&& clist[i].lchan->type == GSM_LCHAN_TCH_H
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&& (clist[i].requirements & REQUIREMENT_C_TCHF))
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continue;
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/* omit candidates that will not solve/reduce congestion */
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if (clist[i].lchan->type == GSM_LCHAN_TCH_F
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&& tchf_congestion <= 0)
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continue;
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if (clist[i].lchan->type == GSM_LCHAN_TCH_H
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&& tchh_congestion <= 0)
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continue;
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avg = clist[i].avg;
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/* improve AHS */
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if (clist[i].lchan->tch_mode == GSM48_CMODE_SPEECH_AMR
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&& clist[i].lchan->type == GSM_LCHAN_TCH_H
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&& (clist[i].requirements & REQUIREMENT_C_TCHF)) {
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avg += ho_get_hodec2_afs_bias_rxlev(clist[i].bts->ho);
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is_improved = 1;
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} else
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is_improved = 0;
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pick_better_lchan_to_move(true, &best_cand, &best_avg_db, &clist[i], avg);
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}
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/* perform handover, if there is a candidate */
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/* Select best candidate that balances congestion.
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* Again no remote BSS.
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* Again no TCH/H -> F upgrades within the same cell. */
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best_cand = pick_best_candidate(&is_improved, clist, candidates,
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/* want_highest_db */ true,
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/* omit_intra_cell_upgrade_to_tchf */ true,
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/* only_intra_cell_upgrade_to_tchf */ false,
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REQUIREMENT_C_MASK);
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if (best_cand) {
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any_ho = 1;
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LOGPHOCAND(best_cand, LOGL_INFO, "Best candidate: RX level %d%s\n",
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@ -1796,62 +1768,29 @@ next_c1:
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#if 0
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next_c2:
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#endif
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/* select worst candidate that fulfills requirement C,
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* select candidates that change from AHS to AFS only */
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if (tchh_congestion > 0) {
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/* since this will only check half rate channels, it will
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* only need to be checked, if tchh is congested */
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worst_avg_db = 999;
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for (i = 0; i < candidates; i++) {
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/* delete subscriber that just have handovered */
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if (clist[i].lchan == delete_lchan)
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clist[i].lchan = NULL;
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/* omit all subscribers that are handovered */
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if (!clist[i].lchan)
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continue;
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/* Do not resolve congestion towards remote BSS, which would cause oscillation if
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* the remote BSS is also congested. */
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/* TODO: see (x) above */
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if (!clist[i].bts)
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continue;
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if (!(clist[i].requirements & REQUIREMENT_C_MASK))
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continue;
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/* omit all but assignment from AHS to AFS */
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if (clist[i].lchan->ts->trx->bts != clist[i].bts
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|| clist[i].lchan->type != GSM_LCHAN_TCH_H
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|| !(clist[i].requirements & REQUIREMENT_C_TCHF))
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continue;
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avg = clist[i].avg;
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/* improve AHS */
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if (clist[i].lchan->tch_mode == GSM48_CMODE_SPEECH_AMR
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&& clist[i].lchan->type == GSM_LCHAN_TCH_H) {
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avg += ho_get_hodec2_afs_bias_rxlev(clist[i].bts->ho);
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is_improved = 1;
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} else
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is_improved = 0;
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LOGP(DHODEC, LOGL_DEBUG, "candidate %d: avg=%d worst_avg_db=%d\n", i, avg,
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worst_avg_db);
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pick_better_lchan_to_move(false, &worst_cand, &worst_avg_db, &clist[i], avg);
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}
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}
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/* Look for upgrading TCH/H to TCH/F within the same cell, which balances congestion, again upgrade the TCH/H
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* lchan that has the worst reception: */
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if (tchh_congestion > 0)
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best_cand = pick_best_candidate(&is_improved, clist, candidates,
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/* want_highest_db */ false,
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/* omit_intra_cell_upgrade_to_tchf */ false,
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/* only_intra_cell_upgrade_to_tchf */ true,
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REQUIREMENT_C_MASK);
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/* perform handover, if there is a candidate */
|
||||
if (worst_cand) {
|
||||
if (best_cand) {
|
||||
any_ho = 1;
|
||||
LOGPHOCAND(worst_cand, LOGL_INFO, "Worst candidate: RX level %d from TCH/H -> TCH/F%s\n",
|
||||
rxlev2dbm(worst_cand->avg),
|
||||
LOGPHOCAND(best_cand, LOGL_INFO, "Worst candidate: RX level %d from TCH/H -> TCH/F%s\n",
|
||||
rxlev2dbm(best_cand->avg),
|
||||
is_improved ? " (applied AHS -> AFS rxlev bias)" : "");
|
||||
trigger_ho(worst_cand, worst_cand->requirements & REQUIREMENT_C_MASK);
|
||||
trigger_ho(best_cand, best_cand->requirements & REQUIREMENT_C_MASK);
|
||||
#if 0
|
||||
/* if there is still congestion, mark lchan as deleted
|
||||
* and redo this process */
|
||||
tchh_congestion--;
|
||||
if (tchh_congestion > 0) {
|
||||
delete_lchan = worst_cand->lchan;
|
||||
worst_cand = NULL;
|
||||
delete_lchan = best_cand->lchan;
|
||||
best_cand = NULL;
|
||||
goto next_c2;
|
||||
}
|
||||
#else
|
||||
|
|
|
|||
Loading…
Reference in New Issue