From 8620f33a58a9883b5159c81d7a0141988328213f Mon Sep 17 00:00:00 2001 From: Thomas Schlichter Date: Fri, 14 Nov 2025 12:33:14 +0100 Subject: [PATCH 1/2] Provide public helper functions to create NR_RLC_Config from nr_rlc_configuration_t --- openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c | 43 +++++++++++--------- openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h | 3 ++ 2 files changed, 26 insertions(+), 20 deletions(-) diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c index 99bf846d4d..dff2f2b663 100644 --- a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c +++ b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.c @@ -3538,6 +3538,24 @@ static NR_SpCellConfig_t *get_initial_SpCellConfig(int uid, return SpCellConfig; } +struct NR_RLC_Config *nr_srb_config(const nr_rlc_configuration_t *default_rlc_config) +{ + NR_RLC_Config_t *rlc_Config = calloc(1, sizeof(NR_RLC_Config_t)); + rlc_Config->present = NR_RLC_Config_PR_am; + rlc_Config->choice.am = calloc(1, sizeof(*rlc_Config->choice.am)); + rlc_Config->choice.am->dl_AM_RLC.sn_FieldLength = calloc(1, sizeof(NR_SN_FieldLengthAM_t)); + *(rlc_Config->choice.am->dl_AM_RLC.sn_FieldLength) = encode_sn_field_length_am(default_rlc_config->srb.sn_field_length); + rlc_Config->choice.am->dl_AM_RLC.t_Reassembly = encode_t_reassembly(default_rlc_config->srb.t_reassembly); + rlc_Config->choice.am->dl_AM_RLC.t_StatusProhibit = encode_t_status_prohibit(default_rlc_config->srb.t_status_prohibit); + rlc_Config->choice.am->ul_AM_RLC.sn_FieldLength = calloc(1, sizeof(NR_SN_FieldLengthAM_t)); + *(rlc_Config->choice.am->ul_AM_RLC.sn_FieldLength) = encode_sn_field_length_am(default_rlc_config->srb.sn_field_length); + rlc_Config->choice.am->ul_AM_RLC.t_PollRetransmit = encode_t_poll_retransmit(default_rlc_config->srb.t_poll_retransmit); + rlc_Config->choice.am->ul_AM_RLC.pollPDU = encode_poll_pdu(default_rlc_config->srb.poll_pdu); + rlc_Config->choice.am->ul_AM_RLC.pollByte = encode_poll_byte(default_rlc_config->srb.poll_byte); + rlc_Config->choice.am->ul_AM_RLC.maxRetxThreshold = encode_max_retx_threshold(default_rlc_config->srb.max_retx_threshold); + return rlc_Config; +} + NR_RLC_BearerConfig_t *get_SRB_RLC_BearerConfig(long channelId, long priority, long bucketSizeDuration, @@ -3551,20 +3569,7 @@ NR_RLC_BearerConfig_t *get_SRB_RLC_BearerConfig(long channelId, rlc_BearerConfig->servedRadioBearer->choice.srb_Identity = channelId; rlc_BearerConfig->reestablishRLC = NULL; - NR_RLC_Config_t *rlc_Config = calloc(1, sizeof(NR_RLC_Config_t)); - rlc_Config->present = NR_RLC_Config_PR_am; - rlc_Config->choice.am = calloc(1, sizeof(*rlc_Config->choice.am)); - rlc_Config->choice.am->dl_AM_RLC.sn_FieldLength = calloc(1, sizeof(NR_SN_FieldLengthAM_t)); - *(rlc_Config->choice.am->dl_AM_RLC.sn_FieldLength) = encode_sn_field_length_am(default_rlc_config->srb.sn_field_length); - rlc_Config->choice.am->dl_AM_RLC.t_Reassembly = encode_t_reassembly(default_rlc_config->srb.t_reassembly); - rlc_Config->choice.am->dl_AM_RLC.t_StatusProhibit = encode_t_status_prohibit(default_rlc_config->srb.t_status_prohibit); - rlc_Config->choice.am->ul_AM_RLC.sn_FieldLength = calloc(1, sizeof(NR_SN_FieldLengthAM_t)); - *(rlc_Config->choice.am->ul_AM_RLC.sn_FieldLength) = encode_sn_field_length_am(default_rlc_config->srb.sn_field_length); - rlc_Config->choice.am->ul_AM_RLC.t_PollRetransmit = encode_t_poll_retransmit(default_rlc_config->srb.t_poll_retransmit); - rlc_Config->choice.am->ul_AM_RLC.pollPDU = encode_poll_pdu(default_rlc_config->srb.poll_pdu); - rlc_Config->choice.am->ul_AM_RLC.pollByte = encode_poll_byte(default_rlc_config->srb.poll_byte); - rlc_Config->choice.am->ul_AM_RLC.maxRetxThreshold = encode_max_retx_threshold(default_rlc_config->srb.max_retx_threshold); - rlc_BearerConfig->rlc_Config = rlc_Config; + rlc_BearerConfig->rlc_Config = nr_srb_config(default_rlc_config); NR_LogicalChannelConfig_t *logicalChannelConfig = calloc(1, sizeof(NR_LogicalChannelConfig_t)); logicalChannelConfig->ul_SpecificParameters = calloc(1, sizeof(*logicalChannelConfig->ul_SpecificParameters)); @@ -3584,10 +3589,9 @@ NR_RLC_BearerConfig_t *get_SRB_RLC_BearerConfig(long channelId, return rlc_BearerConfig; } -static void nr_drb_config(struct NR_RLC_Config *rlc_Config, - NR_RLC_Config_PR rlc_config_pr, - const nr_rlc_configuration_t *default_rlc_config) +struct NR_RLC_Config *nr_drb_config(NR_RLC_Config_PR rlc_config_pr, const nr_rlc_configuration_t *default_rlc_config) { + NR_RLC_Config_t *rlc_Config = calloc(1, sizeof(NR_RLC_Config_t)); switch (rlc_config_pr) { case NR_RLC_Config_PR_um_Bi_Directional: // RLC UM Bi-directional Bearer configuration @@ -3620,6 +3624,7 @@ static void nr_drb_config(struct NR_RLC_Config *rlc_Config, break; } rlc_Config->present = rlc_config_pr; + return rlc_Config; } NR_RLC_BearerConfig_t *get_DRB_RLC_BearerConfig(long lcChannelId, @@ -3635,9 +3640,7 @@ NR_RLC_BearerConfig_t *get_DRB_RLC_BearerConfig(long lcChannelId, rlc_BearerConfig->servedRadioBearer->choice.drb_Identity = drbId; rlc_BearerConfig->reestablishRLC = NULL; - NR_RLC_Config_t *rlc_Config = calloc(1, sizeof(NR_RLC_Config_t)); - nr_drb_config(rlc_Config, rlc_conf, default_rlc_config); - rlc_BearerConfig->rlc_Config = rlc_Config; + rlc_BearerConfig->rlc_Config = nr_drb_config(rlc_conf, default_rlc_config); NR_LogicalChannelConfig_t *logicalChannelConfig = calloc(1, sizeof(NR_LogicalChannelConfig_t)); logicalChannelConfig->ul_SpecificParameters = calloc(1, sizeof(*logicalChannelConfig->ul_SpecificParameters)); diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h index 89ce03e7f5..466f18c0de 100644 --- a/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h +++ b/openair2/LAYER2/NR_MAC_gNB/nr_radio_config.h @@ -112,6 +112,9 @@ NR_CellGroupConfig_t *get_default_secondaryCellGroup(const NR_ServingCellConfigC NR_ReconfigurationWithSync_t *get_reconfiguration_with_sync(rnti_t rnti, uid_t uid, const NR_ServingCellConfigCommon_t *scc, int frame); +struct NR_RLC_Config *nr_srb_config(const nr_rlc_configuration_t *default_rlc_config); +struct NR_RLC_Config *nr_drb_config(NR_RLC_Config_PR rlc_config_pr, const nr_rlc_configuration_t *default_rlc_config); + NR_RLC_BearerConfig_t *get_SRB_RLC_BearerConfig(long channelId, long priority, long bucketSizeDuration, From eb7ca9663cd87a7e68bfcdcf8a032fae244ec9d9 Mon Sep 17 00:00:00 2001 From: Thomas Schlichter Date: Fri, 14 Nov 2025 12:45:37 +0100 Subject: [PATCH 2/2] gNB: modify RLC configuration applied for SRB1 during RRCReestablishment TS 38.331 clause 5.3.7.4 specifies to apply the configuration defined in 9.2.1 for SRB1 at UE side. This implies that the gNB also has to apply sn_field_length = 12, but there are no implications on the other RLC parameters. As wrong timer values break SRB1 e.g. for long RTT NTN scenarios, this commit switches to using the RLC timer values provided in the configuration file. Currently we still set poll_pdu, poll_byte and max_retx_threshold to the values defined in 9.2.1, but this can be changed. --- openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c index 064857a8e3..d353ab9e3f 100644 --- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c +++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c @@ -980,8 +980,15 @@ void dl_rrc_message_transfer(const f1ap_dl_rrc_message_t *dl_rrc) pthread_mutex_unlock(&mac->sched_lock); nr_rlc_remove_ue(dl_rrc->gNB_DU_ue_id); nr_rlc_update_id(*dl_rrc->old_gNB_DU_ue_id, dl_rrc->gNB_DU_ue_id); - /* 38.331 clause 5.3.7.4: apply the specified configuration defined in 9.2.1 for SRB1 */ - nr_rlc_reconfigure_entity(dl_rrc->gNB_DU_ue_id, 1, NULL); + /* 38.331 clause 5.3.7.4: apply gNB RLC configuration for SRB1 to match the UE RLC configuration defined in 9.2.1 */ + nr_rlc_configuration_t rlc_configuration = mac->rlc_config; // use configuration file values for timers t_poll_retransmit, t_reassembly and t_status_prohibit + rlc_configuration.srb.poll_pdu = -1; + rlc_configuration.srb.poll_byte = -1; + rlc_configuration.srb.max_retx_threshold = 8; + rlc_configuration.srb.sn_field_length = 12; + NR_RLC_Config_t *rlc_Config = nr_srb_config(&rlc_configuration); + nr_rlc_reconfigure_entity(dl_rrc->gNB_DU_ue_id, 1, rlc_Config); + ASN_STRUCT_FREE(asn_DEF_NR_RLC_Config, rlc_Config); instance_t f1inst = get_f1_gtp_instance(); if (f1inst >= 0) // we actually use F1-U gtpv1u_update_ue_id(f1inst, *dl_rrc->old_gNB_DU_ue_id, dl_rrc->gNB_DU_ue_id);