new branch

doc/IAB_docs/IAB_Info.md

+<table style="border-collapse: collapse; border: none;">
+  <tr style="border-collapse: collapse; border: none;">
+    <td style="border-collapse: collapse; border: none;">
+      <a href="http://www.openairinterface.org/">
+         <img src="../images/oai_final_logo.png" alt="" border=3 height=50 width=150>
+         </img>
+      </a>
+    </td>
+    <td style="border-collapse: collapse; border: none; vertical-align: center;">
+      <b><font size = "5">OAI IAB Documentation</font></b>
+    </td>
+  </tr>
+</table>
+
+**Table of Contents**
+
+[[_TOC_]]
+
+# Glossary
+
+| Acronym | Description                    |
+| ------- | ------------------------------ |
+| BAP     | Backhaul Adaptation Protocol   |
+| BH      | Backhaul                       |
+| CP      | Control Plane                  |
+| IAB     | Integrated Access and Backhaul |
+| RLC     | Radio Link Control             |
+| RLF     | Radio Link Failure             |
+| RRC     | Radio Resource Control         |
+| TNL     | Transport Network Layer        |
+| UP      | User Plane                     |
+
+# 1. Scenario
+
+This document aims to gather all the needed requirements to implement a 5G SA 3GPP compliant Integrated Access and Backhaul (IAB).
+
+# 2. Protocol Stacks
+
+## 2.1 Protocol stack for the support of F1-U protocol
+
+<img src="./images/Protocol_stack_F1-U.png" width=600>
+
+## 2.2 Protocol stack for the support of F1-C protocol
+
+<img src="./images/Protocol_stack_F1-C.png" width=600>
+
+## 2.3 Protocol stack for the support of IAB-MT's RRC and NAS connections
+
+<img src="./images/Protocol_stack_RRC_NAS.png" width=600>
+
+# 3. Backhaul Adaptation Protocol (BAP) (TS 38.340)
+
+Some info in [BAP_info](./BAP_Info.md)
+
+# 4. F1 Mods (TS 38.470 and 38.473)
+
+Needed functions:
+
+-   BAP mapping configuration function;
+-   gNB-DU resource configuration function;
+-   IAB TNL address configuration function;
+-   IAB UP configuration update function;
+-   Mobile IAB F1 Setup Triggering function; (Can we skip mobile IAB for now?)
+-   Mobile IAB F1 Setup Outcome Notification function. (Can we skip mobile IAB for now?)
+
+# 5. RRC Mods (TS 38.331)
+
+Some info in [RRC_IAB_info](./RRC_IAB_Info.md)
+
+# 6. IAB-MT mandatory features (TS 38.306)
+
+-   Routing using BAP (TS 38.340-i00 (release 18), pages 11-17)
+-   Bearer mapping using BAP (TS 38.340-i00 (release 18), pages 11-17)
+-   IAB-node IP address signalling over RRC (TS 38.331-i00 (release 18), page 133)
+
+<img src="./images/IAB-MT-Requirements.png" width=600>
+
+# 7. IAB Resource Configuration (TS 38.300)
+
+Check TS 38.300-i00 (release 18), pages 122 and 123.
+
+# 8. Required signalling procedures (TS 38.300 and TS 38.401)
+
+## 8.1 IAB-node Integration (TS 38.401-i00, page 87 and 88)
+
+<img src="./images/IAB_node_integration.png" width=600>
+
+## _8.2 IAB-node Migration (Mobile IAB???)_
+
+## 8.3 Topological Management (TS 38.300-i00, page 34)
+
+### 8.3.1 IAB Inter-donor-DU Re-routing (TS 38.401-i00, pages 105, 106)
+
+When an IAB-donor-DU is configured to support inter-donor-DU re-routing, the IAB-donor-DU may identify a rerouted UL IP packet based on the source IP address field of the UL packet, and forwards UL IP packets, whose source IP addresses are anchored at a peer IAB-donor-DU, to this peer IAB-donor-DU via a tunnel. The IAB-donor-DU and the peer IAB-donor-DU may be controlled by the same IAB-donor-CU or by two different IAB-donor-CUs. The interdonor-DU tunnel may be a GTP-U tunnel. The configuration of the tunnel is up to implementation. At the IAB-donor-DU forwarding the UL IP packets, inter-donor-DU tunnelling may be restricted to only a subset of the IP addresses anchored at the peer IAB-donor-DU. For this purpose, the IAB-donor-CU configures the IAB-donor-DU for forwarding the UL IP packets with a list of TNL addresses and/or prefixes for which tunnelling should be permitted and TNL
+address filtering should be exempted.
+
+### 8.3.2 IAB Inter-CU topological redundancy procedure (TS 38.3401-i00, pages 106, 107 and 108)
+
+<img src="./images/IAB_inter-CU_redundancy.png" width=600>
+
+### 8.3.3 IAB Inter-CU topology adaptation procedure (TS 38.3401-i00, pages 108 to 111)
+
+<img src="./images/IAB_inter-CU_topology_adaptation.png" width=600>
+
+### 8.3.4 IAB inter-CU topology adaptation procedure with descendant IAB-node (TS 38.3401-i00, pages 111 to 113)
+
+<img src="./images/IAB_inter-CU_topology_adaptation_descendant.png" width=600>
+
+### 8.3.5 IAB Inter-CU Backhaul RLF recovery for single connected IAB-node (TS 38.3401-i00, pages 113 to 116)
+
+<img src="./images/IAB_inter-CU_BH_RLF_recovery_for_single_node.png" width=600>
+
+## 8.4 OTA timing synchronization (38.300-i00, page 34)
+
+An IAB-DU is subject to the same downlink timing alignment of a gNB. The IAB-DU may use the received downlink
+signal from a parent as a reference to control its downlink timing using TA in conjunction with an additional Tdelta
+parameter received by the collocated IAB-MT from the parent via MAC-CE.
+
+## 8.5 Inter node discovery (38.300-i00, page 35)
+
+Inter node discovery is supported via SSB-based and/or CSI-RS-based measurements. An IAB-node can be configured
+to transmit and receive off synchronization raster SSB signals to discover neighbouring IAB-nodes. The configuration
+is not expected to create a conflict between IAB-DU SSB transmission and IAB-MT SSB measurement windows.

executables/nr-ue.c

@@ -816,16 +816,16 @@ void *UE_thread(void *arg)
         delNotifiedFIFO_elt(res);
         start_rx_stream=0;
       } else {
-	if (IS_SOFTMODEM_IQPLAYER || IS_SOFTMODEM_IQRECORDER) {
-	  // For IQ recorder/player we force synchronization to happen in 280 ms
-	  while (trashed_frames != 28) {
-	    readFrame(UE, &timestamp, true);
-	    trashed_frames+=2;
-	  }
-	} else {
-	  readFrame(UE, &timestamp, true);
-	  trashed_frames+=2;
-	}
+        if (IS_SOFTMODEM_IQPLAYER || IS_SOFTMODEM_IQRECORDER) {
+          // For IQ recorder/player we force synchronization to happen in 280 ms
+          while (trashed_frames != 28) {
+            readFrame(UE, &timestamp, true);
+            trashed_frames+=2;
+          }
+        } else {
+          readFrame(UE, &timestamp, true);
+          trashed_frames+=2;
+        }
         continue;
       }
     }

openair2/RRC/NR/CMakeLists.txt

-add_subdirectory(MESSAGES)
+add_subdirectory(MESSAGES)
\ No newline at end of file

openair2/RRC/NR/MESSAGES/asn1_msg.c

@@ -926,6 +926,68 @@ uint8_t do_RRCSetupComplete(uint8_t *buffer,
   return((enc_rval.encoded+7)/8);
 }
 
+uint8_t do_RRCSetupComplete_IAB(uint8_t *buffer,
+                            size_t buffer_size,
+                            const uint8_t Transaction_id,
+                            uint8_t sel_plmn_id,
+                            const int dedicatedInfoNASLength,
+                            const char *dedicatedInfoNAS)
+{
+    NR_UL_DCCH_Message_t ul_dcch_msg = {0};
+    ul_dcch_msg.message.present = NR_UL_DCCH_MessageType_PR_c1;
+    ul_dcch_msg.message.choice.c1 = CALLOC(1,sizeof(struct NR_UL_DCCH_MessageType__c1));
+    ul_dcch_msg.message.choice.c1->present = NR_UL_DCCH_MessageType__c1_PR_rrcSetupComplete;
+    ul_dcch_msg.message.choice.c1->choice.rrcSetupComplete = CALLOC(1, sizeof(NR_RRCSetupComplete_t));
+    NR_RRCSetupComplete_t *RrcSetupComplete = ul_dcch_msg.message.choice.c1->choice.rrcSetupComplete;
+    RrcSetupComplete->rrc_TransactionIdentifier = Transaction_id;
+    RrcSetupComplete->criticalExtensions.present = NR_RRCSetupComplete__criticalExtensions_PR_rrcSetupComplete;
+    RrcSetupComplete->criticalExtensions.choice.rrcSetupComplete = CALLOC(1, sizeof(NR_RRCSetupComplete_IEs_t));
+    NR_RRCSetupComplete_IEs_t *ies = RrcSetupComplete->criticalExtensions.choice.rrcSetupComplete;
+    ies->selectedPLMN_Identity = sel_plmn_id;
+    ies->registeredAMF = NULL;
+
+    ies->ng_5G_S_TMSI_Value = CALLOC(1, sizeof(struct NR_RRCSetupComplete_IEs__ng_5G_S_TMSI_Value));
+    ies->ng_5G_S_TMSI_Value->present = NR_RRCSetupComplete_IEs__ng_5G_S_TMSI_Value_PR_ng_5G_S_TMSI;
+    NR_NG_5G_S_TMSI_t *stmsi = &ies->ng_5G_S_TMSI_Value->choice.ng_5G_S_TMSI;
+    stmsi->size = 6;
+    stmsi->buf = calloc(stmsi->size, sizeof(*stmsi->buf));
+    AssertFatal(stmsi->buf != NULL, "out of memory\n");
+    stmsi->buf[0] = 0x12;
+    stmsi->buf[1] = 0x34;
+    stmsi->buf[2] = 0x56;
+    stmsi->buf[3] = 0x78;
+    stmsi->buf[4] = 0x9A;
+    stmsi->buf[5] = 0xBC;
+
+    memset(&ies->dedicatedNAS_Message,0,sizeof(OCTET_STRING_t));
+    OCTET_STRING_fromBuf(&ies->dedicatedNAS_Message, dedicatedInfoNAS, dedicatedInfoNASLength);
+    
+    // ----IAB related params---- 
+    ies->nonCriticalExtension = CALLOC(1, sizeof(NR_RRCSetupComplete_v1610_IEs_t));
+    NR_RRCSetupComplete_v1610_IEs_t *v1610_ies = ies->nonCriticalExtension;
+    v1610_ies->iab_NodeIndication_r16 = CALLOC(1, sizeof(long));
+    *v1610_ies->iab_NodeIndication_r16 = NR_RRCSetupComplete_v1610_IEs__iab_NodeIndication_r16_true;
+    // --------------------------
+
+
+
+    if ( LOG_DEBUGFLAG(DEBUG_ASN1) ) {
+        xer_fprint(stdout, &asn_DEF_NR_UL_DCCH_Message, (void *)&ul_dcch_msg);
+    }
+
+    asn_enc_rval_t enc_rval = uper_encode_to_buffer(&asn_DEF_NR_UL_DCCH_Message,
+                                                    NULL,
+                                                    (void *)&ul_dcch_msg,
+                                                    buffer,
+                                                    buffer_size);
+    AssertFatal(enc_rval.encoded > 0,"ASN1 message encoding failed (%s, %lu)!\n",
+                enc_rval.failed_type->name,enc_rval.encoded);
+    LOG_D(NR_RRC,"RRCSetupComplete Encoded %zd bits (%zd bytes)\n",enc_rval.encoded,(enc_rval.encoded+7)/8);
+
+    ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_NR_UL_DCCH_Message, &ul_dcch_msg);
+    return((enc_rval.encoded+7)/8);
+}
+
 uint8_t do_NR_DLInformationTransfer(uint8_t *buffer,
                                     size_t buffer_len,
                                     uint8_t transaction_id,

openair2/RRC/NR/MESSAGES/asn1_msg.h

@@ -115,6 +115,13 @@ uint8_t do_RRCSetupComplete(uint8_t *buffer,
                             const int dedicatedInfoNASLength,
                             const char *dedicatedInfoNAS);
 
+uint8_t do_RRCSetupComplete_IAB(uint8_t *buffer,
+                            size_t buffer_size,
+                            const uint8_t Transaction_id,
+                            uint8_t sel_plmn_id,
+                            const int dedicatedInfoNASLength,
+                            const char *dedicatedInfoNAS);
+
 int do_RRCSetupRequest(uint8_t *buffer, size_t buffer_size, uint8_t *rv);
 
 uint8_t do_NR_RRCReconfigurationComplete_for_nsa(uint8_t *buffer, size_t buffer_size, NR_RRC_TransactionIdentifier_t Transaction_id);

openair2/RRC/NR/nr_rrc_defs.h

@@ -323,6 +323,9 @@ typedef struct gNB_RRC_UE_s {
   /* hack, see rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ() for more info */
   int max_delays_pdu_session;
 
+  /*[IAB] params*/
+  bool                               is_iab_mt;
+
 } gNB_RRC_UE_t;
 
 typedef struct rrc_gNB_ue_context_s {

openair2/RRC/NR/rrc_gNB.c

@@ -145,6 +145,7 @@ typedef struct deliver_dl_rrc_message_data_s {
   f1ap_dl_rrc_message_t *dl_rrc;
   sctp_assoc_t assoc_id;
 } deliver_dl_rrc_message_data_t;
+
 static void rrc_deliver_dl_rrc_message(void *deliver_pdu_data, ue_id_t ue_id, int srb_id, char *buf, int size, int sdu_id)
 {
   DevAssert(deliver_pdu_data != NULL);
@@ -600,6 +601,7 @@ static void rrc_gNB_generate_defaultRRCReconfiguration(const protocol_ctxt_t *co
                                    measconfig,
                                    dedicatedNAS_MessageList,
                                    ue_p->masterCellGroup);
+                                   
   AssertFatal(size > 0, "cannot encode RRCReconfiguration in %s()\n", __func__);
   free_defaultMeasConfig(measconfig);
   freeSRBlist(SRBs);
@@ -1539,6 +1541,19 @@ static int handle_rrcSetupComplete(const protocol_ctxt_t *const ctxt_pP,
     }
   }
 
+  // [IAB] related configs
+  if (setup_complete_ies->nonCriticalExtension != NULL){
+    if (*setup_complete_ies->nonCriticalExtension->iab_NodeIndication_r16 == NR_RRCSetupComplete_v1610_IEs__iab_NodeIndication_r16_true){
+      LOG_I(NR_RRC, "IAB Node Indication received and set to true\n");
+      UE->is_iab_mt = true;
+      // Call UE Context modification request.
+      
+    } else{
+      UE->is_iab_mt = false;
+    }
+  }
+  // -------------------
+
   rrc_gNB_process_RRCSetupComplete(ctxt_pP, ue_context_p, setup_complete->criticalExtensions.choice.rrcSetupComplete);
   LOG_I(NR_RRC, PROTOCOL_NR_RRC_CTXT_UE_FMT " UE State = NR_RRC_CONNECTED \n", PROTOCOL_NR_RRC_CTXT_UE_ARGS(ctxt_pP));
   return 0;

openair2/RRC/NR_UE/rrc_UE.c

@@ -834,7 +834,8 @@ static void rrc_ue_generate_RRCSetupComplete(const NR_UE_RRC_INST_t *rrc, const
     nas_msg_length = sizeof(nr_nas_attach_req_imsi_dummy_NSA_case);
   }
 
-  size = do_RRCSetupComplete(buffer, sizeof(buffer), Transaction_id, rrc->selected_plmn_identity, nas_msg_length, nas_msg);
+  //size = do_RRCSetupComplete(buffer, sizeof(buffer), Transaction_id, rrc->selected_plmn_identity, nas_msg_length, nas_msg);
+  size = do_RRCSetupComplete_IAB(buffer, sizeof(buffer), Transaction_id, rrc->selected_plmn_identity, nas_msg_length, nas_msg);
   LOG_I(NR_RRC, "[UE %ld][RAPROC] Logical Channel UL-DCCH (SRB1), Generating RRCSetupComplete (bytes%d)\n", rrc->ue_id, size);
   int srb_id = 1; // RRC setup complete on SRB1
   LOG_D(NR_RRC, "[RRC_UE %ld] PDCP_DATA_REQ/%d Bytes RRCSetupComplete ---> %d\n", rrc->ue_id, size, srb_id);