Change in osmo-bsc[2021q1]: bitvec2freq_list(): fix handling of E-GSM ARFCNs

fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmo-bsc/+/27381 ) Change subject: bitvec2freq_list(): fix handling of E-GSM ARFCNs ...................................................................... bitvec2freq_list(): fix handling of E-GSM ARFCNs According to 3GPP TS 44.018, section 10.5.2.1b.2, only ARFCN values in range 1..124 can be encoded using the 'bit map 0' format. Before this patch, ARFCN values belonging to E-GSM band (0, 975..1023) were ignored in bitvec2freq_list(), and thus not present in the resulting Cell Channel Description IE. Change-Id: I17739e6845cd84e2a81bc406dd532541f7c52cb6 Related: SYS#5854 --- M src/osmo-bsc/system_information.c M tests/gsm0408/gsm0408_test.ok 2 files changed, 19 insertions(+), 10 deletions(-) Approvals: Jenkins Builder: Verified pespin: Looks good to me, but someone else must approve fixeria: Looks good to me, approved diff --git a/src/osmo-bsc/system_information.c b/src/osmo-bsc/system_information.c index 7ec613c..20685a9 100644 --- a/src/osmo-bsc/system_information.c +++ b/src/osmo-bsc/system_information.c @@ -504,20 +504,29 @@ bool pgsm = false; memset(chan_list, 0, 16); - if (bts->band == GSM_BAND_900 - && bts->c0->arfcn >= 1 && bts->c0->arfcn <= 124) + /* According to 3GPP TS 44.018, section 10.5.2.1b.2, only ARFCN values + * in range 1..124 can be encoded using the 'bit map 0' format. */ + if (bts->band == GSM_BAND_900) pgsm = true; + /* Check presence of E-GSM ARFCN 0 */ + if (pgsm && bitvec_get_bit_pos(bv, 0) == ONE) + pgsm = false; + /* Check presence of E-GSM ARFCNs 975..1023 */ + for (i = 975; pgsm && i <= 1023; i++) { + if (bitvec_get_bit_pos(bv, i) == ONE) + pgsm = false; + } + /* P-GSM-only handsets only support 'bit map 0 format' */ if (!bis && !ter && pgsm) { chan_list[0] = 0; - for (i = 0; i < bv->data_len*8; i++) { - if (i >= 1 && i <= 124 - && bitvec_get_bit_pos(bv, i)) { - rc = freq_list_bm0_set_arfcn(chan_list, i); - if (rc < 0) - return rc; - } + for (i = 1; i <= 124; i++) { + if (!bitvec_get_bit_pos(bv, i)) + continue; + rc = freq_list_bm0_set_arfcn(chan_list, i); + if (rc < 0) + return rc; } return 0; } diff --git a/tests/gsm0408/gsm0408_test.ok b/tests/gsm0408/gsm0408_test.ok index 38b5b4b..264a9c7 100644 --- a/tests/gsm0408/gsm0408_test.ok +++ b/tests/gsm0408/gsm0408_test.ok @@ -247,6 +247,6 @@ Testing generation of the Cell Channel Description IE: Case a) only the BCCH carrier: 10 Case b) more carriers from P-GSM band: 1 3 10 64 99 124 -Case c) more carriers from E-GSM band: 1 3 10 64 99 124 +Case c) more carriers from E-GSM band: 0 3 10 64 99 124 975 1001 1023 BTS deallocated OK in test_cell_chan_desc() Done. -- To view, visit https://gerrit.osmocom.org/c/osmo-bsc/+/27381 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-bsc Gerrit-Branch: 2021q1 Gerrit-Change-Id: I17739e6845cd84e2a81bc406dd532541f7c52cb6 Gerrit-Change-Number: 27381 Gerrit-PatchSet: 1 Gerrit-Owner: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-Reviewer: laforge &lt;laforge(a)osmocom.org&gt; Gerrit-Reviewer: pespin &lt;pespin(a)sysmocom.de&gt; Gerrit-MessageType: merged