Sidelink configuration passed from RRC->MAC, defined interface functions

	- Phy configuration will be prepared by MAC
	- Sidelink preconfiguration parameters passed from RRC->MAC
	- Only 1 SSB TA allocation used
	- psbch payload prepared by MAC after receiving the tx slss req

CMakeLists.txt

@@ -1369,9 +1369,11 @@ set (MAC_NR_SRC_UE
   ${NR_UE_PHY_INTERFACE_DIR}/NR_IF_Module.c
   ${NR_UE_PHY_INTERFACE_DIR}/NR_Packet_Drop.c
   ${NR_UE_MAC_DIR}/config_ue.c
+  ${NR_UE_MAC_DIR}/config_ue_sl.c
   ${NR_UE_MAC_DIR}/mac_vars.c
   ${NR_UE_MAC_DIR}/main_ue_nr.c
   ${NR_UE_MAC_DIR}/nr_ue_procedures.c
+  ${NR_UE_MAC_DIR}/nr_ue_procedures_sl.c
   ${NR_UE_MAC_DIR}/nr_ue_scheduler.c
   ${NR_UE_MAC_DIR}/nr_ue_dci_configuration.c
   ${NR_UE_MAC_DIR}/nr_ra_procedures.c

executables/nr-ue.c

@@ -973,6 +973,9 @@ void init_NR_UE(int nb_inst,
     AssertFatal((mac_inst = nr_l2_init_ue(rrc_inst)) != NULL, "can not initialize L2 module\n");
     AssertFatal((mac_inst->if_module = nr_ue_if_module_init(inst)) != NULL, "can not initialize IF module\n");
   }
+  if (get_softmodem_params()->sl_mode) {
+    configure_NR_SL_Preconfig(0, get_softmodem_params()->sync_ref);
+  }
 }
 
 void init_NR_UE_threads(int nb_inst) {

executables/nr-uesoftmodem.c

@@ -503,6 +503,10 @@ int main( int argc, char **argv ) {
   if (!get_softmodem_params()->nsa && get_softmodem_params()->emulate_l1)
     start_oai_nrue_threads();
 
+  if (get_softmodem_params()->sl_mode) {
+    nr_UE_configure_Sidelink(0, get_softmodem_params()->sync_ref);
+  }
+
   if (!get_softmodem_params()->emulate_l1) {
     for (int CC_id=0; CC_id<MAX_NUM_CCs; CC_id++) {
       PHY_vars_UE_g[0][CC_id] = (PHY_VARS_NR_UE *)malloc(sizeof(PHY_VARS_NR_UE));

nfapi/open-nFAPI/nfapi/public_inc/sidelink_nr_ue_interface.h

@@ -351,7 +351,7 @@ typedef struct
   uint16_t sl_bandwidth;
   //Absolute frequency of SL point A in KHz
   //n38 (2570-2620 Mhz), n47 (5855-5925 Mhz) are defined.
-  uint32_t sl_frequency;
+  uint64_t sl_frequency;
 
   //Only 1 SCS-SpecificCarrier allowed for NR-SL communication
   uint16_t sl_grid_size;// bandwidth for each numerology
@@ -363,7 +363,7 @@ typedef struct
   uint8_t  sl_frequency_shift_7p5khz;
   //Indicates presence of +/-5Khz shift wrt FREF for V2X reference frequencies.
   //Possible values: {-1,0,1}
-  uint8_t  sl_value_N;
+  int8_t  sl_value_N;
 
 } sl_nr_carrier_config_t;
 

openair2/LAYER2/NR_MAC_UE/mac_defs.h

@@ -47,6 +47,7 @@
 #include "LAYER2/NR_MAC_COMMON/nr_mac_common.h"
 #include "LAYER2/MAC/mac.h"
 #include "NR_MAC_COMMON/nr_mac_extern.h"
+#include "mac_defs_sl.h"
 
 /* RRC */
 #include "NR_DRX-Config.h"
@@ -526,6 +527,9 @@ typedef struct {
 
   pthread_mutex_t mutex_dl_info;
 
+  //SIDELINK MAC PARAMETERS
+  sl_nr_ue_mac_params_t *SL_MAC_PARAMS;
+
 } NR_UE_MAC_INST_t;
 
 /*@}*/

openair2/LAYER2/NR_MAC_UE/mac_defs_sl.h

+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#ifndef __MAC_DEFS_SL_H__
+#define __MAC_DEFS_SL_H__
+
+#include "sidelink_nr_ue_interface.h"
+#include "NR_SL-ResourcePool-r16.h"
+#include "NR_TDD-UL-DL-ConfigCommon.h"
+#include "NR_MAC_COMMON/nr_mac.h"
+#include "NR_UE_PHY_INTERFACE/NR_IF_Module.h"
+
+
+#define SL_NR_MAC_NUM_RX_RESOURCE_POOLS 1
+#define SL_NR_MAC_NUM_TX_RESOURCE_POOLS 1
+#define SL_NUM_BYTES_TIMERESOURCEBITMAP 20
+
+// Size of Fixed fields prio (3), sci_2ndstage(2),
+// betaoffsetindicator(2), num dmrs ports (1), mcs (5bits)
+#define SL_SCI_FORMAT_1A_LEN_IN_BITS_FIXED_FIELDS 13
+
+#define sci_field_t dci_field_t
+
+typedef struct sidelink_sci_format_1a_fields {
+
+  // Priority of this transmission
+  uint8_t     priority; //3 bits
+  //Indicates the format to be used in 2nd stage i.e SCI format 2 sent on PSSCH
+  //00 - SCI FORMAT 2A, 01 - SCI FORMAT 2B, 10, 11 - Reserved
+  //Spec 38.212 Table 8.3.1.1-1
+  uint8_t     sci_format_2nd_stage; //2 bits
+  //Num modulated symbols for stage 2 SCI - TBD:
+  // Spec 38.212 Table 8.3.1.1-2
+  uint8_t     beta_offset_indicator; //2 bits
+  //determine the number of layers for data on PSSCH
+  // Spec 38.212 Table 8.3.1.1-3
+  uint8_t     num_dmrs_ports; //1 bit
+  //Modulation and coding scheme to be used for data on PSSCH
+  uint8_t     mcs; //5 bits
+
+  //Identifies the frequence resource (subchannels) to be used for PSSCH/PSCCH
+  //sl-MaxNumPerReserve is 2 - ceil(log2(N_subch*(N_subch+1)/2)) bits
+  //sl-MaxNumPerReserve is 3 - ceil(log2(N_subch*(N_subch+1)(2*N_subch+1)/6)) bits
+  sci_field_t frequency_resource_assignment; //variable
+  //Identifies the Time resource (slots) to be used for PSSCH/PSCCH
+  //sl-MaxNumPerReserve is 2 - 5 bits
+  //sl-MaxNumPerReserve is 3 - 9 bits
+  sci_field_t time_resource_assignment; //variable
+  //TBD:
+  //sl-MultiReserveResource is not configured - 0 bits
+  //sl-MultiReserveResource is configured - ceil(log2(number of entries in sl-ResourceReservePeriodList)) bits
+  sci_field_t resource_reservation_period; //variable
+  //Identifies the DMRS Pattern to be used on PSSCH
+  //ceil(log2(number of dmrs patterns in sl-PSSCH-DMRS-TimePatternList)) bits
+  sci_field_t dmrs_pattern; //variable
+  //Identifies the TABLE to be used to determine MCS on PSSCH
+  //1 table configured in sl-Additional-MCS-Table - 1 bit
+  //2 tables configured in sl-Additional-MCS-Table - 2 bits
+  //Not configured- 0 bits
+  sci_field_t additional_mcs_table_indicator; //variable
+  //Identifies the number of symbols for PSFCH
+  //sl-PSFCH-Period Not configured- 0 bits
+  //if sl-PSFCH-Period configured and value 2 or 4 - 1 bit
+  sci_field_t psfch_overhead_indication; //variable
+  //number of bits determined by sl-NumReservedbits
+  //Value encoded is 0
+  sci_field_t reserved_bits;
+
+} sidelink_sci_format_1a_fields_t;
+
+typedef struct SL_ResourcePool_params {
+
+  //This holds the structure from RRC
+  NR_SL_ResourcePool_r16_t *respool;
+
+  //NUM Subchannels in this resource pool
+  uint16_t num_subch;
+
+  //SCI-1A length is the same for this resource pool.
+  uint16_t sci_1a_len;
+
+  //SCI-1A configuration according to RESPOOL configured.
+  sidelink_sci_format_1a_fields_t sci_1a;
+
+} SL_ResourcePool_params_t;
+
+typedef struct sl_ssb_timealloc {
+
+  uint32_t sl_NumSSB_WithinPeriod;
+  uint32_t sl_TimeOffsetSSB;
+  uint32_t sl_TimeInterval;
+
+} sl_ssb_timealloc_t;
+
+typedef struct sl_bch_params {
+
+  //configured from RRC
+  //Parameters used to determine PSBCH slot
+  sl_ssb_timealloc_t ssb_time_alloc;
+  uint16_t slss_id;
+  bool     status;
+  uint8_t  sl_mib[4];
+
+  //Parameters incremented by MAC PSBCH scheduler
+  //after every SSB txn/reception
+  uint16_t num_ssb;
+  uint16_t ssb_slot;
+
+} sl_bch_params_t;
+
+typedef struct sl_nr_ue_mac_params {
+
+  //Holds the RX resource pool from RRC and its related parameters
+  SL_ResourcePool_params_t *sl_RxPool[SL_NR_MAC_NUM_RX_RESOURCE_POOLS];
+  //Holds the TX resource pool from RRC and its related parameters
+  SL_ResourcePool_params_t *sl_TxPool[SL_NR_MAC_NUM_TX_RESOURCE_POOLS];
+
+  //Holds either the TDD config from RRC
+  //or TDD config decoded from SL-MIB
+  NR_TDD_UL_DL_ConfigCommon_t *sl_TDD_config;
+
+  //Configured from RRC
+  uint32_t sl_MaxNumConsecutiveDTX;
+  uint32_t sl_SSB_PriorityNR;
+  uint8_t sl_CSI_Acquisition;
+
+  //MAC prepares this and sends it to PHY
+  nr_sl_phy_config_t sl_phy_config;
+
+  //Holds Broadcast params incase UE sends Sidelink SSB
+  sl_bch_params_t tx_sl_bch;
+  //Holds Broadcast params incase UE receives SL-SSB
+  sl_bch_params_t rx_sl_bch;
+
+} sl_nr_ue_mac_params_t;
+
+
+#endif

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -430,5 +430,29 @@ int nr_config_pusch_pdu(NR_UE_MAC_INST_t *mac,
                         RAR_grant_t *rar_grant,
                         uint16_t rnti,
                         const nr_dci_format_t *dci_format);
+
+int nr_rrc_mac_config_req_sl_preconfig(module_id_t module_id,
+                                       NR_SL_PreconfigurationNR_r16_t *sl_preconfiguration,
+                                       uint8_t sync_source);
+
+void nr_rrc_mac_transmit_slss_req(module_id_t module_id,
+                                  uint8_t *sl_mib_payload,
+                                  uint16_t tx_slss_id,
+                                  NR_SL_SSB_TimeAllocation_r16_t *ssb_ta);
+void nr_rrc_mac_config_req_sl_mib(module_id_t module_id,
+                                  NR_SL_SSB_TimeAllocation_r16_t *ssb_ta,
+                                  uint16_t rx_slss_id,
+                                  uint8_t *sl_mib);
+void sl_prepare_psbch_payload(NR_TDD_UL_DL_ConfigCommon_t *TDD_UL_DL_Config,
+                              uint8_t *bits_0_to_7, uint8_t *bits_8_to_11,
+                              uint8_t mu, uint8_t L, uint8_t Y);
+
+uint8_t sl_decode_sl_TDD_Config(NR_TDD_UL_DL_ConfigCommon_t *TDD_UL_DL_Config,
+                                uint8_t bits_0_to_7, uint8_t bits_8_to_11,
+                                uint8_t mu, uint8_t L, uint8_t Y);
+
+uint8_t sl_determine_sci_1a_len(uint16_t *num_subchannels,
+                                NR_SL_ResourcePool_r16_t *rpool,
+                                sidelink_sci_format_1a_fields_t *sci_1a);
 #endif
 /** @}*/

openair2/RRC/NR_UE/rrc_UE.c

@@ -453,7 +453,7 @@ NR_UE_RRC_INST_t* openair_rrc_top_init_ue_nr(char* uecap_file, char* rrc_config_
     }
 
     if (get_softmodem_params()->sl_mode) {
-      configure_NR_SL_Preconfig(get_softmodem_params()->sync_ref);
+      configure_NR_SL_Preconfig(0,get_softmodem_params()->sync_ref);
     }
   }
   else{

openair2/RRC/NR_UE/rrc_defs.h

@@ -53,6 +53,8 @@
 #include "NR_DL-DCCH-Message.h"
 #include "NR_SystemInformation.h"
 #include "NR_UE-NR-Capability.h"
+#include "NR_SL-PreconfigurationNR-r16.h"
+#include "NR_MasterInformationBlockSidelink.h"
 
 #include "RRC/NR/nr_rrc_common.h"
 #include "as_message.h"
@@ -254,6 +256,11 @@ typedef struct NR_UE_RRC_INST_s {
   Rrc_State_NR_t     nrRrcState;
   Rrc_Sub_State_NR_t nrRrcSubState;
   as_nas_info_t      initialNasMsg;
+
+  //Sidelink params
+  NR_SL_PreconfigurationNR_r16_t *sl_preconfig;
+  NR_MasterInformationBlockSidelink_t *sl_mib;
+
 } NR_UE_RRC_INST_t;
 
 #endif

openair2/RRC/NR_UE/rrc_proto.h

@@ -173,7 +173,9 @@ void handle_rlf_sync(NR_UE_Timers_Constants_t *tac,
 void nr_rrc_handle_SetupRelease_RLF_TimersAndConstants(NR_UE_RRC_INST_t *rrc,
                                                        struct NR_SetupRelease_RLF_TimersAndConstants *rlf_TimersAndConstants);
 
-int configure_NR_SL_Preconfig(int sync_source);
+int configure_NR_SL_Preconfig(uint8_t id,int sync_source);
+void nr_UE_configure_Sidelink(uint8_t id, uint8_t is_sync_source);
+
 /** @}*/
 #endif
 

openair2/RRC/NR_UE/rrc_sl_preconfig.c

@@ -27,6 +27,19 @@
 #include "common/utils/LOG/log.h"
 #include "sl_preconfig_paramvalues.h"
 #include "common/config/config_userapi.h"
+#include "rrc_defs.h"
+#include "rrc_vars.h"
+#include "LAYER2/NR_MAC_UE/mac_proto.h"
+
+#define GNSS_SUPPORT 0
+
+#define SL_SYNC_SOURCE_NONE  0 //No sync source selected
+#define SL_SYNC_SOURCE_GNBENB 1 // GNB/ENB as sync source
+#define SL_SYNC_SOURCE_GNSS 2 // GPS as sync source
+#define SL_SYNC_SOURCE_SYNC_REF_UE 3 // another SYNC REF UE as sync source
+#define SL_SYNC_SOURCE_LOCAL_TIMING 4 //UE acts as sync source
+
+
 
 static void prepare_NR_SL_SyncConfig(NR_SL_SyncConfig_r16_t *sl_syncconfig)
 {
@@ -399,8 +412,7 @@ NR_SL_PreconfigurationNR_r16_t *prepare_NR_SL_PRECONFIGURATION(uint16_t num_tx_p
   return sl_preconfiguration;
 }
 
-
-int configure_NR_SL_Preconfig(int sync_source)
+int configure_NR_SL_Preconfig(uint8_t id,int sync_source)
 {
 
   NR_SL_PreconfigurationNR_r16_t *sl_preconfig = NULL;
@@ -424,9 +436,155 @@ int configure_NR_SL_Preconfig(int sync_source)
     }
   }
 
-  ASN_STRUCT_FREE(asn_DEF_NR_SL_PreconfigurationNR_r16, sl_preconfig);
-  sl_preconfig = NULL;
-  //END.......
+  NR_UE_RRC_INST_t *rrc = &NR_UE_rrc_inst[id];
+  rrc->sl_preconfig = sl_preconfig;
 
   return 0;
 }
+
+/*
+* This functions configures SIdelink operation in the UE.
+* RRC configures MAC with sidelink parameters
+* In case UE is a sync source/Master UE - then sends transmit SLSS REQ
+*/
+void nr_UE_configure_Sidelink(uint8_t id, uint8_t is_sync_source) {
+
+  NR_UE_RRC_INST_t *rrc = &NR_UE_rrc_inst[id];
+
+  AssertFatal(rrc, "Check if rrc instance was created.");
+
+  NR_SL_PreconfigurationNR_r16_t *sl_preconfig = rrc->sl_preconfig;
+  AssertFatal(sl_preconfig, "Check if SL-preconfig was created.");
+
+  uint8_t sync_source = SL_SYNC_SOURCE_NONE;
+
+  if (is_sync_source) {
+    sync_source = (GNSS_SUPPORT) ? SL_SYNC_SOURCE_GNSS
+                                 : SL_SYNC_SOURCE_LOCAL_TIMING;
+  }
+
+  nr_rrc_mac_config_req_sl_preconfig(id, sl_preconfig, sync_source);
+
+  //TBD.. These should be chosen by RRC according to 3GPP 38.331 RRC specification.
+  //Currently hardcoding the values to these
+  uint16_t slss_id = 671, ssb_ta_index = 1;
+  //12 bits -sl-TDD-config will be filled by MAC
+  //Incoverage 1bit is FALSE
+  //DFN, sfn will be filled by PHY
+  uint8_t sl_mib_payload[4] = {0,0,0,0};
+
+  NR_SL_SSB_TimeAllocation_r16_t *ssb_ta = NULL;
+  NR_SL_FreqConfigCommon_r16_t *fcfg = NULL;
+  NR_SL_SyncConfig_r16_t *synccfg = NULL;
+  if (rrc->sl_preconfig->sidelinkPreconfigNR_r16.sl_PreconfigFreqInfoList_r16)
+    fcfg = rrc->sl_preconfig->sidelinkPreconfigNR_r16.sl_PreconfigFreqInfoList_r16->list.array[0];
+  AssertFatal(fcfg, "Fcfg cannot be NULL\n");
+  if (fcfg->sl_SyncConfigList_r16)
+    synccfg = fcfg->sl_SyncConfigList_r16->list.array[0];
+  AssertFatal(synccfg, "Synccfg cannot be NULL\n");
+
+  if (ssb_ta_index == 1)
+    ssb_ta = synccfg->sl_SSB_TimeAllocation1_r16;
+  else if (ssb_ta_index == 2)
+    ssb_ta = synccfg->sl_SSB_TimeAllocation2_r16;
+  else if (ssb_ta_index == 3)
+    ssb_ta = synccfg->sl_SSB_TimeAllocation3_r16;
+  else DevAssert(0);
+
+  AssertFatal(ssb_ta, "SSB_timeallocation cannot be NULL\n");
+
+  if (sync_source == SL_SYNC_SOURCE_LOCAL_TIMING || sync_source == SL_SYNC_SOURCE_GNSS)
+    nr_rrc_mac_transmit_slss_req(id,sl_mib_payload, slss_id, ssb_ta);
+
+}
+
+
+/*decode SL-BCH (SL-MIB) message*/
+static int8_t nr_sl_rrc_ue_decode_SL_MIB(const module_id_t module_id,
+                                          const uint8_t gNB_index,
+                                          uint8_t *const bufferP,
+                                          const uint8_t buffer_len)
+{
+  NR_MasterInformationBlockSidelink_t *sl_mib = NULL;
+
+  asn_dec_rval_t dec_rval = uper_decode_complete(NULL, &asn_DEF_NR_MasterInformationBlockSidelink,
+                                                 (void **)&sl_mib,
+                                                 (const void *)bufferP, buffer_len);
+
+  uint16_t val_fn = sl_mib->directFrameNumber_r16.buf[0];
+  val_fn = (val_fn << 2) + (sl_mib->directFrameNumber_r16.buf[1] >> sl_mib->directFrameNumber_r16.bits_unused);
+
+  uint8_t val_slot = sl_mib->slotIndex_r16.buf[0];
+
+  LOG_D(NR_RRC, "SL-MIB Contents - DFN:%d\n" , val_fn);
+  LOG_D(NR_RRC, "SL-MIB Contents - SLOT:%d\n" , val_slot >> 1);
+  LOG_D(NR_RRC, "SL-MIB Contents - Incoverage:%d\n", sl_mib->inCoverage_r16);
+  LOG_D(NR_RRC, "SL-MIB Contents - sl-TDD-Config:%x\n" , *((uint16_t *)(sl_mib->sl_TDD_Config_r16.buf)));
+
+  int ret = 1;
+  if ((dec_rval.code != RC_OK) || (dec_rval.consumed == 0)) {
+    LOG_E(NR_RRC, "SL-MIB decode error\n");
+    ret = -1;
+  } else  {
+    ret = 0;
+    if (NR_UE_rrc_inst[module_id].sl_mib == NULL) {
+      LOG_I(NR_RRC, "Sidelink RRC first MIB reception\n");
+    } else {
+      ASN_STRUCT_FREE(asn_DEF_NR_MasterInformationBlockSidelink, NR_UE_rrc_inst[module_id].sl_mib);
+    }
+    NR_UE_rrc_inst[module_id].sl_mib = sl_mib;
+  }
+
+  return ret;
+}
+
+
+
+void nr_mac_rrc_sl_mib_ind(const module_id_t module_id,
+                              const int CC_id,
+                              const uint8_t gNB_index,
+                              const frame_t frame,
+                              const int slot,
+                              const channel_t channel,
+                              uint8_t* pduP,
+                              const sdu_size_t pdu_len,
+                              const uint16_t rx_slss_id)
+{
+
+  nr_sl_rrc_ue_decode_SL_MIB(module_id, gNB_index, (uint8_t*)pduP, pdu_len);
+
+  DevAssert(NR_UE_rrc_inst[module_id].sl_preconfig);
+
+  NR_SL_FreqConfigCommon_r16_t *fcfg = NULL;
+  if (NR_UE_rrc_inst[module_id].sl_preconfig->sidelinkPreconfigNR_r16.sl_PreconfigFreqInfoList_r16)
+    fcfg = NR_UE_rrc_inst[module_id].sl_preconfig->sidelinkPreconfigNR_r16.sl_PreconfigFreqInfoList_r16->list.array[0];
+  DevAssert(fcfg);
+
+  NR_SL_SSB_TimeAllocation_r16_t *sl_SSB_TimeAllocation = NULL;
+
+  //Current implementation only supports one SSB Timeallocation
+  //Extend RRC to use multiple SSB Time allocations TBD....
+  if (fcfg->sl_SyncConfigList_r16)
+    sl_SSB_TimeAllocation = fcfg->sl_SyncConfigList_r16->list.array[0]->sl_SSB_TimeAllocation1_r16;
+  DevAssert(sl_SSB_TimeAllocation);
+
+  nr_rrc_mac_config_req_sl_mib(module_id,
+                               sl_SSB_TimeAllocation,
+                               rx_slss_id,
+                               pduP);
+
+  return;
+}
+
+
+void free_sl_rrc(uint8_t id) {
+
+  NR_UE_RRC_INST_t *rrc = &NR_UE_rrc_inst[id];
+
+  if (rrc->sl_preconfig) {
+    ASN_STRUCT_FREE(asn_DEF_NR_SL_PreconfigurationNR_r16, rrc->sl_preconfig);
+  }
+  if (rrc->sl_mib) {
+    ASN_STRUCT_FREE(asn_DEF_NR_MasterInformationBlockSidelink, rrc->sl_mib);
+  }
+}
\ No newline at end of file