From d38188e153d42adc1c203446b47a3c8fd913004e Mon Sep 17 00:00:00 2001
From: Guido Casati <hello@guidocasati.com>
Date: Wed, 21 Jan 2026 12:30:56 +0100
Subject: [PATCH] RRC: remove unused drbs configuration parameter

- Delete drbs field from gNB_RrcConfigurationReq and its use in RCconfig_NRRRC()
- Remove GNB_CONFIG_STRING_DRBS, help text, index, and GNBPARAMS_CHECK entry from gnb_paramdef.h
- Drop DU-side verification and DRB count logging in gnb_config.c
---
 doc/RRC/rrc-usage.md                 |  2 --
 openair2/COMMON/rrc_messages_types.h |  1 -
 openair2/GNB_APP/gnb_config.c        |  3 ---
 openair2/GNB_APP/gnb_paramdef.h      | 33 ++++++++++++----------------
 4 files changed, 14 insertions(+), 25 deletions(-)

diff --git a/doc/RRC/rrc-usage.md b/doc/RRC/rrc-usage.md
index bae31e864a..05f55d5123 100644
--- a/doc/RRC/rrc-usage.md
+++ b/doc/RRC/rrc-usage.md
@@ -94,8 +94,6 @@ the [MAC configuration](../MAC/mac-usage.md) as well for SIB configuration.
 
 - `um_on_default_drb` (default: false): use RLC UM instead of RLC AM on default
   bearers
-- `drbs` (default: 0): the number of DRBs to allocate for a UE, only useful for
-  do-ra or phy-test testing
 
 #### Neighbor-gNB configuration
 
diff --git a/openair2/COMMON/rrc_messages_types.h b/openair2/COMMON/rrc_messages_types.h
index cfc6914f4b..6b69959168 100644
--- a/openair2/COMMON/rrc_messages_types.h
+++ b/openair2/COMMON/rrc_messages_types.h
@@ -422,7 +422,6 @@ typedef struct NRRrcConfigurationReq_s {
 
   bool um_on_default_drb;
   bool                    enable_sdap;
-  int                     drbs;
 } gNB_RrcConfigurationReq;
 
 typedef struct NRDuDlReq_s {
diff --git a/openair2/GNB_APP/gnb_config.c b/openair2/GNB_APP/gnb_config.c
index 0b3845f5b9..01c44650ae 100644
--- a/openair2/GNB_APP/gnb_config.c
+++ b/openair2/GNB_APP/gnb_config.c
@@ -717,7 +717,6 @@ void RCconfig_verify(configmodule_interface_t *cfg, ngran_node_t node_type)
   } else if (NODE_IS_DU(node_type)) {
     // verify that there is no bearer config
     verify_gnb_param_notset(gnbp, GNB_ENABLE_SDAP_IDX, GNB_CONFIG_STRING_ENABLE_SDAP);
-    verify_gnb_param_notset(gnbp, GNB_DRBS, GNB_CONFIG_STRING_DRBS);
 
     verify_section_notset(cfg, GNB_CONFIG_STRING_GNB_LIST ".[0]", GNB_CONFIG_STRING_AMF_IP_ADDRESS);
     verify_section_notset(cfg, NULL, CONFIG_STRING_SECURITY);
@@ -2092,9 +2091,7 @@ gNB_RRC_INST *RCconfig_NRRRC()
         nrrrc_config.num_plmn = set_plmn_config(nrrrc_config.plmn, k);
         nrrrc_config.enable_sdap = *GNBParamList.paramarray[i][GNB_ENABLE_SDAP_IDX].iptr;
         LOG_I(GNB_APP, "SDAP layer is %s\n", nrrrc_config.enable_sdap ? "enabled" : "disabled");
-        nrrrc_config.drbs = *GNBParamList.paramarray[i][GNB_DRBS].iptr;
         nrrrc_config.um_on_default_drb = *(GNBParamList.paramarray[i][GNB_UMONDEFAULTDRB_IDX].uptr);
-        LOG_I(GNB_APP, "Data Radio Bearer count %d\n", nrrrc_config.drbs);
 
       }//
     }//End for (k=0; k <num_gnbs ; k++)
diff --git a/openair2/GNB_APP/gnb_paramdef.h b/openair2/GNB_APP/gnb_paramdef.h
index 4a34e8d0e0..09a19b2d33 100644
--- a/openair2/GNB_APP/gnb_paramdef.h
+++ b/openair2/GNB_APP/gnb_paramdef.h
@@ -110,7 +110,6 @@ typedef enum {
 #define GNB_CONFIG_STRING_MAXMIMOLAYERS                 "maxMIMO_layers"
 #define GNB_CONFIG_STRING_DISABLE_HARQ                  "disable_harq"
 #define GNB_CONFIG_STRING_ENABLE_SDAP                   "enable_sdap"
-#define GNB_CONFIG_STRING_DRBS                          "drbs"
 #define GNB_CONFIG_STRING_USE_DELTA_MCS                 "use_deltaMCS"
 #define GNB_CONFIG_HLP_USE_DELTA_MCS                    "Use deltaMCS-based power headroom reporting in PUSCH-Config"
 #define GNB_CONFIG_HLP_FORCEUL256QAMOFF                 "suppress activation of UL 256 QAM despite UE support"
@@ -130,7 +129,6 @@ typedef enum {
 #define GNB_CONFIG_HLP_FORCE256QAMOFF                   "suppress activation of 256 QAM despite UE support"
 #define GNB_CONFIG_HLP_MAXMIMOLAYERS                    "limit on maxMIMO-layers for DL"
 #define GNB_CONFIG_HLP_DISABLE_HARQ                     "disable feedback for all HARQ processes (REL17 feature)"
-#define GNB_CONFIG_HLP_STRING_DRBS                      "Number of total DRBs to establish, including the mandatory for PDU SEssion (default=1)\n"
 #define GNB_CONFIG_HLP_GNB_DU_ID                        "defines the gNB-DU ID (only applicable for DU)"
 #define GNB_CONFIG_HLP_GNB_CU_UP_ID                     "defines the gNB-CU-UP ID (only applicable for CU-UP)"
 #define GNB_CONFIG_HLP_NUM_DL_HARQ                      "Set Num DL harq processes. Valid values 2,4,6,8,10,12,16,32. Default 16"
@@ -173,7 +171,6 @@ typedef enum {
 {GNB_CONFIG_STRING_UMONDEFAULTDRB,               NULL, PARAMFLAG_BOOL, .uptr=NULL,  .defuintval=0,                TYPE_UINT,      0},  \
 {GNB_CONFIG_STRING_FORCE256QAMOFF, GNB_CONFIG_HLP_FORCE256QAMOFF, PARAMFLAG_BOOL, .iptr=NULL, .defintval=0,       TYPE_INT,       0},  \
 {GNB_CONFIG_STRING_ENABLE_SDAP, GNB_CONFIG_HLP_STRING_ENABLE_SDAP, PARAMFLAG_BOOL,.iptr=NULL, .defintval=0,       TYPE_INT,       0},  \
-{GNB_CONFIG_STRING_DRBS, GNB_CONFIG_HLP_STRING_DRBS,     0,           .iptr=NULL,   .defintval=1,                 TYPE_INT,       0},  \
 {GNB_CONFIG_STRING_GNB_DU_ID, GNB_CONFIG_HLP_GNB_DU_ID,  0,           .u64ptr=NULL, .defint64val=1,               TYPE_UINT64,    0},  \
 {GNB_CONFIG_STRING_GNB_CU_UP_ID, GNB_CONFIG_HLP_GNB_CU_UP_ID, 0,      .u64ptr=NULL, .defint64val=1,               TYPE_UINT64,    0},  \
 {GNB_CONFIG_STRING_USE_DELTA_MCS, GNB_CONFIG_HLP_USE_DELTA_MCS, 0,    .iptr=NULL,   .defintval=0,                 TYPE_INT,       0},  \
@@ -219,21 +216,20 @@ typedef enum {
 #define GNB_UMONDEFAULTDRB_IDX          23
 #define GNB_FORCE256QAMOFF_IDX          24
 #define GNB_ENABLE_SDAP_IDX             25
-#define GNB_DRBS                        26
-#define GNB_GNB_DU_ID_IDX               27
-#define GNB_GNB_CU_UP_ID_IDX            28
-#define GNB_USE_DELTA_MCS_IDX           29
-#define GNB_FORCEUL256QAMOFF_IDX        30
-#define GNB_MAXMIMOLAYERS_IDX           31
-#define GNB_DISABLE_HARQ_IDX            32
-#define GNB_NUM_DL_HARQ_IDX             33
-#define GNB_NUM_UL_HARQ_IDX             34
-#define GNB_UESS_AGG_LEVEL_LIST_IDX     35
-#define GNB_CU_SIBS_IDX                 36
-#define GNB_DU_SIBS_IDX                 37
-#define GNB_CONFIG_REP_IDX              38
-#define GNB_1ST_ACTIVE_BWP_IDX          39
-#define GNB_LIMIT_RSRP_REPORT_IDX       40
+#define GNB_GNB_DU_ID_IDX               26
+#define GNB_GNB_CU_UP_ID_IDX            27
+#define GNB_USE_DELTA_MCS_IDX           28
+#define GNB_FORCEUL256QAMOFF_IDX        29
+#define GNB_MAXMIMOLAYERS_IDX           30
+#define GNB_DISABLE_HARQ_IDX            31
+#define GNB_NUM_DL_HARQ_IDX             32
+#define GNB_NUM_UL_HARQ_IDX             33
+#define GNB_UESS_AGG_LEVEL_LIST_IDX     34
+#define GNB_CU_SIBS_IDX                 35
+#define GNB_DU_SIBS_IDX                 36
+#define GNB_CONFIG_REP_IDX              37
+#define GNB_1ST_ACTIVE_BWP_IDX          38
+#define GNB_LIMIT_RSRP_REPORT_IDX       39
 
 #define TRACKING_AREA_CODE_OKRANGE {0x0001,0xFFFD}
 #define NUM_DL_HARQ_OKVALUES {2,4,6,8,10,12,16,32}
@@ -272,7 +268,6 @@ typedef enum {
   { .s5 = { NULL } },                                             \
   { .s5 = { NULL } },                                             \
   { .s5 = { NULL } },                                             \
-  { .s5 = { NULL } },                                             \
   { .s1 =  { config_check_intval, NUM_DL_HARQ_OKVALUES,8 } },     \
   { .s1 =  { config_check_intval, NUM_UL_HARQ_OKVALUES,2 } },     \
   { .s5 = { NULL } },                                             \