Change in osmo-bsc[master]: gsm48_parse_meas_rep: fix parsing multi-band list

osmith has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bsc/+/29836 ) Change subject: gsm48_parse_meas_rep: fix parsing multi-band list ...................................................................... gsm48_parse_meas_rep: fix parsing multi-band list When looking up "BCCH-FREQ-NCELL i" from the measurement report, don't treat the BCCH channel list as one list sorted by ascending ARFCN. Instead, treat it as two sub lists, one for the same band, and one for channels in different bands, as described in 3GPP TS 04.08 § 10.5.2.20. This fixes getting the wrong ARFCN from measurement reports in multi-band BSS, which leads to failing handovers. Fixes: OS#5717 Related: osmo-ttcn3-hacks I4fe6bb9e4b5a69ea6204585ebdf1f157a68a8286 Change-Id: Ic5e4f0531e08685460948b102367825588d839ba --- M include/osmocom/bsc/system_information.h M src/osmo-bsc/gsm_04_08_rr.c M src/osmo-bsc/system_information.c 3 files changed, 39 insertions(+), 7 deletions(-) git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/36/29836/1 diff --git a/include/osmocom/bsc/system_information.h b/include/osmocom/bsc/system_information.h index 08d34f8..7b1cff0 100644 --- a/include/osmocom/bsc/system_information.h +++ b/include/osmocom/bsc/system_information.h @@ -7,6 +7,7 @@ struct gsm_bts; +int band_compatible(const struct gsm_bts *bts, int arfcn); int generate_cell_chan_alloc(struct gsm_bts *bts); int generate_cell_chan_list(uint8_t *chan_list, struct gsm_bts *bts); int gsm_generate_si(struct gsm_bts *bts, enum osmo_sysinfo_type type); diff --git a/src/osmo-bsc/gsm_04_08_rr.c b/src/osmo-bsc/gsm_04_08_rr.c index 3321a0e..151ea73 100644 --- a/src/osmo-bsc/gsm_04_08_rr.c +++ b/src/osmo-bsc/gsm_04_08_rr.c @@ -766,6 +766,37 @@ return 0; } +/* Get the ARFCN from the BCCH channel list by the index "BCCH-FREQ-NCELL i" + * (idx) as described in 3GPP TS 04.08 § 10.5.2.20. The BCCH channel list is + * split into two sub lists, each ascendingly ordered by the ARFCN: + * 1) SI* and SI*bis entries + * 2) SI*ter entries (if available) + * Both sub lists are stored in one bitvec (nbv), iterate twice through it. */ +static int neigh_list_get_arfcn(struct gsm_bts *bts, struct bitvec *nbv, unsigned int idx) +{ + unsigned int sublist, arfcn, i = 0; + bool ter; + + for (sublist = 1; sublist <= 2; sublist++) { + for (arfcn = 0; arfcn < nbv->data_len * 8; arfcn++) { + /* Skip ARFCNs that aren't in any sub list */ + if (bitvec_get_bit_pos(nbv, arfcn) == ZERO) + continue; + + /* Skip SI*ter (1) / require SI*ter (2) */ + ter = !band_compatible(bts, arfcn); + if ((sublist == 1 && ter) || (sublist == 2 && !ter)) + continue; + + if (i == idx) + return arfcn; + i++; + } + } + + return 0; +} + int gsm48_parse_meas_rep(struct gsm_meas_rep *rep, struct msgb *msg) { struct gsm48_hdr *gh = msgb_l3(msg); @@ -800,7 +831,7 @@ mrc = &rep->cell[0]; mrc->rxlev = data[3] & 0x3f; mrc->neigh_idx = data[4] >> 3; - mrc->arfcn = bitvec_get_nth_set_bit(nbv, mrc->neigh_idx + 1); + mrc->arfcn = neigh_list_get_arfcn(bts, nbv, mrc->neigh_idx); mrc->bsic = ((data[4] & 0x07) << 3) | (data[5] >> 5); if (rep->num_cell < 2) return 0; @@ -808,7 +839,7 @@ mrc = &rep->cell[1]; mrc->rxlev = ((data[5] & 0x1f) << 1) | (data[6] >> 7); mrc->neigh_idx = (data[6] >> 2) & 0x1f; - mrc->arfcn = bitvec_get_nth_set_bit(nbv, mrc->neigh_idx + 1); + mrc->arfcn = neigh_list_get_arfcn(bts, nbv, mrc->neigh_idx); mrc->bsic = ((data[6] & 0x03) << 4) | (data[7] >> 4); if (rep->num_cell < 3) return 0; @@ -816,7 +847,7 @@ mrc = &rep->cell[2]; mrc->rxlev = ((data[7] & 0x0f) << 2) | (data[8] >> 6); mrc->neigh_idx = (data[8] >> 1) & 0x1f; - mrc->arfcn = bitvec_get_nth_set_bit(nbv, mrc->neigh_idx + 1); + mrc->arfcn = neigh_list_get_arfcn(bts, nbv, mrc->neigh_idx); mrc->bsic = ((data[8] & 0x01) << 5) | (data[9] >> 3); if (rep->num_cell < 4) return 0; @@ -824,7 +855,7 @@ mrc = &rep->cell[3]; mrc->rxlev = ((data[9] & 0x07) << 3) | (data[10] >> 5); mrc->neigh_idx = data[10] & 0x1f; - mrc->arfcn = bitvec_get_nth_set_bit(nbv, mrc->neigh_idx + 1); + mrc->arfcn = neigh_list_get_arfcn(bts, nbv, mrc->neigh_idx); mrc->bsic = data[11] >> 2; if (rep->num_cell < 5) return 0; @@ -832,7 +863,7 @@ mrc = &rep->cell[4]; mrc->rxlev = ((data[11] & 0x03) << 4) | (data[12] >> 4); mrc->neigh_idx = ((data[12] & 0xf) << 1) | (data[13] >> 7); - mrc->arfcn = bitvec_get_nth_set_bit(nbv, mrc->neigh_idx + 1); + mrc->arfcn = neigh_list_get_arfcn(bts, nbv, mrc->neigh_idx); mrc->bsic = (data[13] >> 1) & 0x3f; if (rep->num_cell < 6) return 0; @@ -840,7 +871,7 @@ mrc = &rep->cell[5]; mrc->rxlev = ((data[13] & 0x01) << 5) | (data[14] >> 3); mrc->neigh_idx = ((data[14] & 0x07) << 2) | (data[15] >> 6); - mrc->arfcn = bitvec_get_nth_set_bit(nbv, mrc->neigh_idx + 1); + mrc->arfcn = neigh_list_get_arfcn(bts, nbv, mrc->neigh_idx); mrc->bsic = data[15] & 0x3f; return 0; diff --git a/src/osmo-bsc/system_information.c b/src/osmo-bsc/system_information.c index 48f7453..cfc9a04 100644 --- a/src/osmo-bsc/system_information.c +++ b/src/osmo-bsc/system_information.c @@ -52,7 +52,7 @@ * array. DCS1800 and PCS1900 can not be used at the same time so conserve * memory and do the below. */ -static int band_compatible(const struct gsm_bts *bts, int arfcn) +int band_compatible(const struct gsm_bts *bts, int arfcn) { enum gsm_band band; -- To view, visit https://gerrit.osmocom.org/c/osmo-bsc/+/29836 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-bsc Gerrit-Branch: master Gerrit-Change-Id: Ic5e4f0531e08685460948b102367825588d839ba Gerrit-Change-Number: 29836 Gerrit-PatchSet: 1 Gerrit-Owner: osmith &lt;osmith(a)sysmocom.de&gt; Gerrit-MessageType: newchange