/* * Copyright 2013-2020 Software Radio Systems Limited * * This file is part of srsLTE. * * srsLTE is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of * the License, or (at your option) any later version. * * srsLTE is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * A copy of the GNU Affero General Public License can be found in * the LICENSE file in the top-level directory of this distribution * and at http://www.gnu.org/licenses/. * */ #include "srsenb/hdr/phy/phy_ue_db.h" using namespace srsenb; void phy_ue_db::init(stack_interface_phy_lte* stack_ptr, const phy_args_t& phy_args_, const phy_cell_cfg_list_t& cell_cfg_list_) { stack = stack_ptr; phy_args = &phy_args_; cell_cfg_list = &cell_cfg_list_; } inline void phy_ue_db::_add_rnti(uint16_t rnti) { // Private function not mutexed // Assert RNTI does NOT exist if (ue_db.count(rnti)) { return; } // Create new UE by accesing it ue_db[rnti].cell_info[0] = {}; // Get UE common_ue& ue = ue_db[rnti]; // Load default values to PCell ue.cell_info[0].phy_cfg.set_defaults(); // Set constant configuration fields _set_common_config_rnti(rnti, ue.cell_info[0].phy_cfg); // Configure as PCell ue.cell_info[0].state = cell_state_primary; // Iterate all pending ACK for (uint32_t tti = 0; tti < TTIMOD_SZ; tti++) { _clear_tti_pending_rnti(tti, rnti); } } inline void phy_ue_db::_clear_tti_pending_rnti(uint32_t tti, uint16_t rnti) { // Private function not mutexed, no need to assert RNTI or TTI // Get UE common_ue& ue = ue_db[rnti]; srslte_pdsch_ack_t& pdsch_ack = ue.pdsch_ack[tti]; // Reset ACK information pdsch_ack = {}; uint32_t nof_active_cc = 0; for (auto& cell_info : ue.cell_info) { if (cell_info.state == cell_state_primary or cell_info.state == cell_state_secondary_active) { nof_active_cc++; } } // Copy essentials. It is assumed the PUCCH parameters are the same for all carriers pdsch_ack.transmission_mode = ue.cell_info[0].phy_cfg.dl_cfg.tm; pdsch_ack.nof_cc = nof_active_cc; pdsch_ack.ack_nack_feedback_mode = ue.cell_info[0].phy_cfg.ul_cfg.pucch.ack_nack_feedback_mode; pdsch_ack.simul_cqi_ack = ue.cell_info[0].phy_cfg.ul_cfg.pucch.simul_cqi_ack; } inline void phy_ue_db::_set_common_config_rnti(uint16_t rnti, srslte::phy_cfg_t& phy_cfg) const { // Set common parameters phy_cfg.dl_cfg.pdsch.rnti = rnti; phy_cfg.ul_cfg.pucch.rnti = rnti; phy_cfg.ul_cfg.pusch.rnti = rnti; phy_cfg.ul_cfg.pusch.meas_time_en = true; phy_cfg.ul_cfg.pusch.meas_epre_en = phy_args->pusch_meas_epre; phy_cfg.ul_cfg.pusch.meas_ta_en = phy_args->pusch_meas_ta; phy_cfg.ul_cfg.pusch.meas_evm_en = phy_args->pusch_meas_evm; phy_cfg.ul_cfg.pucch.threshold_format1 = SRSLTE_PUCCH_DEFAULT_THRESHOLD_FORMAT1; phy_cfg.ul_cfg.pucch.threshold_data_valid_format1a = SRSLTE_PUCCH_DEFAULT_THRESHOLD_FORMAT1A; phy_cfg.ul_cfg.pucch.threshold_data_valid_format2 = SRSLTE_PUCCH_DEFAULT_THRESHOLD_FORMAT2; phy_cfg.ul_cfg.pucch.threshold_dmrs_detection = SRSLTE_PUCCH_DEFAULT_THRESHOLD_DMRS; } inline uint32_t phy_ue_db::_get_ue_cc_idx(uint16_t rnti, uint32_t enb_cc_idx) const { uint32_t ue_cc_idx = 0; const common_ue& ue = ue_db.at(rnti); for (; ue_cc_idx < SRSLTE_MAX_CARRIERS; ue_cc_idx++) { const cell_info_t& scell_info = ue.cell_info[ue_cc_idx]; if (scell_info.enb_cc_idx == enb_cc_idx and scell_info.state != cell_state_secondary_inactive) { return ue_cc_idx; } } return ue_cc_idx; } inline int phy_ue_db::_assert_rnti(uint16_t rnti) const { if (not ue_db.count(rnti)) { ERROR("Trying to access RNTI 0x%X, it does not exist.\n", rnti); return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_enb_cc(uint16_t rnti, uint32_t enb_cc_idx) const { // Assert RNTI exist if (_assert_rnti(rnti) != SRSLTE_SUCCESS) { return SRSLTE_ERROR; } // Check Component Carrier is part of UE SCell map if (_get_ue_cc_idx(rnti, enb_cc_idx) == SRSLTE_MAX_CARRIERS) { return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_enb_pcell(uint16_t rnti, uint32_t enb_cc_idx) const { if (_assert_enb_cc(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return SRSLTE_ERROR; } // Check cell is PCell const cell_info_t& cell_info = ue_db.at(rnti).cell_info[_get_ue_cc_idx(rnti, enb_cc_idx)]; if (cell_info.state != cell_state_primary) { return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_ue_cc(uint16_t rnti, uint32_t ue_cc_idx) const { if (_assert_rnti(rnti) != SRSLTE_SUCCESS) { return SRSLTE_ERROR; } // Check SCell is active, ignore PCell state if (ue_cc_idx == SRSLTE_MAX_CARRIERS) { ERROR("Out-of-bounds UE cell/carrier %d for RNTI 0x%X.\n", ue_cc_idx, rnti); return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_active_ue_cc(uint16_t rnti, uint32_t ue_cc_idx) const { if (_assert_ue_cc(rnti, ue_cc_idx) != SRSLTE_SUCCESS) { return SRSLTE_ERROR; } // Return error if not PCell or not Active SCell const cell_info_t& cell_info = ue_db.at(rnti).cell_info[ue_cc_idx]; if (cell_info.state != cell_state_primary and cell_info.state != cell_state_secondary_active) { ERROR("Failed to assert active UE cell/carrier %d for RNTI 0x%X", ue_cc_idx, rnti); return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_active_enb_cc(uint16_t rnti, uint32_t enb_cc_idx) const { if (_assert_enb_cc(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return SRSLTE_ERROR; } // Check SCell is active, ignore PCell state const cell_info_t& cell_info = ue_db.at(rnti).cell_info[_get_ue_cc_idx(rnti, enb_cc_idx)]; if (cell_info.state != cell_state_primary and cell_info.state != cell_state_secondary_active) { return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_stack() const { if (stack == nullptr) { return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline int phy_ue_db::_assert_cell_list_cfg() const { if (cell_cfg_list == nullptr) { return SRSLTE_ERROR; } return SRSLTE_SUCCESS; } inline srslte::phy_cfg_t phy_ue_db::_get_rnti_config(uint16_t rnti, uint32_t enb_cc_idx, bool stashed) const { srslte::phy_cfg_t default_cfg = {}; default_cfg.set_defaults(); default_cfg.dl_cfg.pdsch.rnti = rnti; default_cfg.ul_cfg.pucch.rnti = rnti; default_cfg.ul_cfg.pusch.rnti = rnti; // Use default configuration for non-user C-RNTI if (not SRSLTE_RNTI_ISUSER(rnti)) { return default_cfg; } // Make sure the C-RNTI exists and the cell/carrier is configured if (_assert_enb_cc(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { ERROR("Trying to access cell/carrier %d in RNTI 0x%X. It is not active.\n", enb_cc_idx, rnti); return default_cfg; } uint32_t ue_cc_idx = _get_ue_cc_idx(rnti, enb_cc_idx); // Return Stashed configuration if PCell and stashed is true if (ue_cc_idx == 0 and stashed) { return ue_db.at(rnti).pcell_cfg_stash; } // Otherwise return current configuration return ue_db.at(rnti).cell_info.at(ue_cc_idx).phy_cfg; } void phy_ue_db::clear_tti_pending_ack(uint32_t tti) { std::lock_guard lock(mutex); // Iterate all UEs for (auto& iter : ue_db) { _clear_tti_pending_rnti(TTIMOD(tti), iter.first); } } void phy_ue_db::addmod_rnti(uint16_t rnti, const phy_interface_rrc_lte::phy_rrc_dedicated_list_t& phy_rrc_dedicated_list) { std::lock_guard lock(mutex); // Create new user if did not exist if (ue_db.count(rnti) == 0) { _add_rnti(rnti); } // Get UE by reference common_ue& ue = ue_db[rnti]; // Number of configured secondary serving cells uint32_t nof_configured_scell = 0; // Iterate PHY RRC configuration for each UE cell/carrier uint32_t nof_cc = SRSLTE_MIN(phy_rrc_dedicated_list.size(), SRSLTE_MAX_CARRIERS); for (uint32_t ue_cc_idx = 0; ue_cc_idx < nof_cc; ue_cc_idx++) { const phy_interface_rrc_lte::phy_rrc_dedicated_t& phy_rrc_dedicated = phy_rrc_dedicated_list[ue_cc_idx]; // Configured, add/modify entry in the cell_info map cell_info_t& cell_info = ue.cell_info[ue_cc_idx]; // Configure PHY if (cell_info.state == cell_state_primary) { // If primary serving cell's eNb cell/carrier index changed, it applies default current config if (cell_info.enb_cc_idx != phy_rrc_dedicated.enb_cc_idx) { cell_info.phy_cfg.set_defaults(); _set_common_config_rnti(rnti, cell_info.phy_cfg); } // Apply primmary serving cell configuration in stash ue.pcell_cfg_stash = phy_rrc_dedicated.phy_cfg; _set_common_config_rnti(rnti, ue.pcell_cfg_stash); } else if (phy_rrc_dedicated.configured) { // cell_info.phy_cfg = phy_rrc_dedicated.phy_cfg; _set_common_config_rnti(rnti, cell_info.phy_cfg); // Set Cell state, all inactive by default cell_info.state = cell_state_secondary_inactive; // Count Serving cell nof_configured_scell++; } else { // Cell without configuration (except PCell) cell_info.state = cell_state_none; } // Set serving cell index cell_info.enb_cc_idx = phy_rrc_dedicated.enb_cc_idx; } // Disable the rest of potential serving cells for (uint32_t i = nof_cc; i < SRSLTE_MAX_CARRIERS; i++) { ue.cell_info[i].state = cell_state_none; } // Enable/Disable extended CSI field in DCI according to 3GPP 36.212 R10 5.3.3.1.1 Format 0 for (uint32_t ue_cc_idx = 0; ue_cc_idx < nof_cc; ue_cc_idx++) { if (ue.cell_info[ue_cc_idx].state == cell_state_primary) { // The primary cell applies changes in the stashed config ue.pcell_cfg_stash.dl_cfg.dci.multiple_csi_request_enabled = (nof_configured_scell > 0); } else { // The rest apply changes directly ue.cell_info[ue_cc_idx].phy_cfg.dl_cfg.dci.multiple_csi_request_enabled = (nof_configured_scell > 0); } } // Copy necessary PCell configuration for receiving Configuration Completion from UE srslte::phy_cfg_t& pcell_cfg = ue.cell_info[0].phy_cfg; // Setup temporal PUCCH configuration srslte_pucch_cfg_t tmp_pucch_cfg = ue.pcell_cfg_stash.ul_cfg.pucch; tmp_pucch_cfg.N_pucch_1 = pcell_cfg.ul_cfg.pucch.N_pucch_1; ///< Used for ACK // Load new UL configuration pcell_cfg.ul_cfg = ue.pcell_cfg_stash.ul_cfg; // Overwrite PUCCH with temporal PUCCH pcell_cfg.ul_cfg.pucch = tmp_pucch_cfg; } void phy_ue_db::rem_rnti(uint16_t rnti) { std::lock_guard lock(mutex); if (ue_db.count(rnti) != 0) { ue_db.erase(rnti); } } void phy_ue_db::complete_config(uint16_t rnti) { std::lock_guard lock(mutex); // Makes sure the RNTI exists if (_assert_rnti(rnti) != SRSLTE_SUCCESS) { return; } // Apply stashed configuration ue_db[rnti].cell_info[0].phy_cfg = ue_db[rnti].pcell_cfg_stash; } void phy_ue_db::activate_deactivate_scell(uint16_t rnti, uint32_t ue_cc_idx, bool activate) { std::lock_guard lock(mutex); // Assert RNTI and SCell are valid if (_assert_ue_cc(rnti, ue_cc_idx) != SRSLTE_SUCCESS) { return; } cell_info_t& cell_info = ue_db[rnti].cell_info[ue_cc_idx]; // If scell is default only complain if (activate and cell_info.state == cell_state_none) { ERROR("RNTI 0x%X SCell %d has received an activation MAC command but it was not configured\n", rnti, ue_cc_idx); return; } // Set scell state cell_info.state = (activate) ? cell_state_secondary_active : cell_state_secondary_inactive; } bool phy_ue_db::is_pcell(uint16_t rnti, uint32_t enb_cc_idx) const { std::lock_guard lock(mutex); return _assert_enb_pcell(rnti, enb_cc_idx) == SRSLTE_SUCCESS; } srslte_dl_cfg_t phy_ue_db::get_dl_config(uint16_t rnti, uint32_t enb_cc_idx) const { std::lock_guard lock(mutex); return _get_rnti_config(rnti, enb_cc_idx, false).dl_cfg; } srslte_dci_cfg_t phy_ue_db::get_dci_dl_config(uint16_t rnti, uint32_t enb_cc_idx) const { std::lock_guard lock(mutex); return _get_rnti_config(rnti, enb_cc_idx, false).dl_cfg.dci; } srslte_ul_cfg_t phy_ue_db::get_ul_config(uint16_t rnti, uint32_t enb_cc_idx) const { std::lock_guard lock(mutex); return _get_rnti_config(rnti, enb_cc_idx, false).ul_cfg; } srslte_dci_cfg_t phy_ue_db::get_dci_ul_config(uint16_t rnti, uint32_t enb_cc_idx) const { std::lock_guard lock(mutex); return _get_rnti_config(rnti, enb_cc_idx, true).dl_cfg.dci; } void phy_ue_db::set_ack_pending(uint32_t tti, uint32_t enb_cc_idx, const srslte_dci_dl_t& dci) { std::lock_guard lock(mutex); // Assert rnti and cell exits and it is active if (_assert_active_enb_cc(dci.rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return; } common_ue& ue = ue_db[dci.rnti]; uint32_t ue_cc_idx = _get_ue_cc_idx(dci.rnti, enb_cc_idx); srslte_pdsch_ack_cc_t& pdsch_ack_cc = ue.pdsch_ack[TTIMOD(tti)].cc[ue_cc_idx]; pdsch_ack_cc.M = 1; ///< Hardcoded for FDD // Fill PDSCH ACK information srslte_pdsch_ack_m_t& pdsch_ack_m = pdsch_ack_cc.m[0]; ///< Assume FDD only pdsch_ack_m.present = true; pdsch_ack_m.resource.grant_cc_idx = ue_cc_idx; ///< Assumes no cross-carrier scheduling pdsch_ack_m.resource.v_dai_dl = 0; ///< Ignore for FDD pdsch_ack_m.resource.n_cce = dci.location.ncce; pdsch_ack_m.resource.tpc_for_pucch = dci.tpc_pucch; // Set TB info for (uint32_t tb_idx = 0; tb_idx < SRSLTE_MAX_CODEWORDS; tb_idx++) { // Count only if the TB is enabled and the TB index is valid for the DCI format if (SRSLTE_DCI_IS_TB_EN(dci.tb[tb_idx]) and tb_idx < srslte_dci_format_max_tb(dci.format)) { pdsch_ack_m.value[tb_idx] = 1; pdsch_ack_m.k++; } else { pdsch_ack_m.value[tb_idx] = 2; } } } bool phy_ue_db::fill_uci_cfg(uint32_t tti, uint32_t enb_cc_idx, uint16_t rnti, bool aperiodic_cqi_request, bool is_pusch_available, srslte_uci_cfg_t& uci_cfg) { std::lock_guard lock(mutex); // Reset UCI CFG, avoid returning carrying cached information uci_cfg = {}; // Assert rnti and cell exits and it is PCell if (_assert_enb_pcell(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return false; } // Assert Cell List configuration if (_assert_cell_list_cfg() != SRSLTE_SUCCESS) { return false; } common_ue& ue = ue_db.at(rnti); const srslte::phy_cfg_t& pcell_cfg = ue.cell_info[0].phy_cfg; bool uci_required = false; const cell_info_t& pcell_info = ue.cell_info[0]; const srslte_cell_t& pcell = cell_cfg_list->at(pcell_info.enb_cc_idx).cell; // Check if SR opportunity (will only be used in PUCCH) uci_cfg.is_scheduling_request_tti = (srslte_ue_ul_sr_send_tti(&pcell_cfg.ul_cfg.pucch, tti) == 1); uci_required |= uci_cfg.is_scheduling_request_tti; // Get pending CQI reports for this TTI, stops at first CC reporting bool periodic_cqi_required = false; for (uint32_t cell_idx = 0; cell_idx < SRSLTE_MAX_CARRIERS and not periodic_cqi_required; cell_idx++) { const cell_info_t& cell_info = ue.cell_info[cell_idx]; const srslte_dl_cfg_t& dl_cfg = cell_info.phy_cfg.dl_cfg; // Check report for primary and active cells if (cell_info.state == cell_state_primary or cell_info.state == cell_state_secondary_active) { const srslte_cell_t& cell = cell_cfg_list->at(cell_info.enb_cc_idx).cell; // Check if CQI report is required periodic_cqi_required = srslte_enb_dl_gen_cqi_periodic(&cell, &dl_cfg, tti, cell_info.last_ri, &uci_cfg.cqi); // Save SCell index for using it after uci_cfg.cqi.scell_index = cell_idx; } } uci_required |= periodic_cqi_required; // If no periodic CQI report required, check aperiodic reporting if ((not periodic_cqi_required) and aperiodic_cqi_request) { // Aperiodic only supported for PCell const srslte_dl_cfg_t& dl_cfg = pcell_info.phy_cfg.dl_cfg; uci_required = srslte_enb_dl_gen_cqi_aperiodic(&pcell, &dl_cfg, pcell_info.last_ri, &uci_cfg.cqi); } // Get pending ACKs from PDSCH srslte_dl_sf_cfg_t dl_sf_cfg = {}; dl_sf_cfg.tti = tti; srslte_pdsch_ack_t& pdsch_ack = ue.pdsch_ack[TTIMOD(tti)]; pdsch_ack.is_pusch_available = is_pusch_available; srslte_enb_dl_gen_ack(&pcell, &dl_sf_cfg, &pdsch_ack, &uci_cfg); uci_required |= (srslte_uci_cfg_total_ack(&uci_cfg) > 0); // Return whether UCI needs to be decoded return uci_required; } void phy_ue_db::send_uci_data(uint32_t tti, uint16_t rnti, uint32_t enb_cc_idx, const srslte_uci_cfg_t& uci_cfg, const srslte_uci_value_t& uci_value) { std::lock_guard lock(mutex); // Assert UE RNTI database entry and eNb cell/carrier must be primary cell if (_assert_enb_pcell(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return; } // Assert Stack if (_assert_stack() != SRSLTE_SUCCESS) { return; } // Notify SR if (uci_cfg.is_scheduling_request_tti && uci_value.scheduling_request) { stack->sr_detected(tti, rnti); } // Get UE common_ue& ue = ue_db.at(rnti); // Get ACK info srslte_pdsch_ack_t& pdsch_ack = ue.pdsch_ack[TTIMOD(tti)]; srslte_enb_dl_get_ack(&cell_cfg_list->at(ue.cell_info[0].enb_cc_idx).cell, &uci_cfg, &uci_value, &pdsch_ack); // Iterate over the ACK information for (uint32_t ue_cc_idx = 0; ue_cc_idx < SRSLTE_MAX_CARRIERS; ue_cc_idx++) { const srslte_pdsch_ack_cc_t& pdsch_ack_cc = pdsch_ack.cc[ue_cc_idx]; for (uint32_t m = 0; m < pdsch_ack_cc.M; m++) { if (pdsch_ack_cc.m[m].present) { for (uint32_t tb = 0; tb < SRSLTE_MAX_CODEWORDS; tb++) { if (pdsch_ack_cc.m[m].value[tb] != 2) { stack->ack_info(tti, rnti, ue.cell_info[ue_cc_idx].enb_cc_idx, tb, pdsch_ack_cc.m[m].value[tb] == 1); } } } } } // Assert the SCell exists and it is active _assert_active_ue_cc(rnti, uci_cfg.cqi.scell_index); // Get CQI carrier index cell_info_t& cqi_scell_info = ue_db.at(rnti).cell_info[uci_cfg.cqi.scell_index]; uint32_t cqi_cc_idx = cqi_scell_info.enb_cc_idx; // Notify CQI only if CRC is valid if (uci_value.cqi.data_crc) { // Channel quality indicator itself if (uci_cfg.cqi.data_enable) { uint8_t cqi_value = 0; switch (uci_cfg.cqi.type) { case SRSLTE_CQI_TYPE_WIDEBAND: cqi_value = uci_value.cqi.wideband.wideband_cqi; break; case SRSLTE_CQI_TYPE_SUBBAND: cqi_value = uci_value.cqi.subband.subband_cqi; break; case SRSLTE_CQI_TYPE_SUBBAND_HL: cqi_value = uci_value.cqi.subband_hl.wideband_cqi_cw0; break; case SRSLTE_CQI_TYPE_SUBBAND_UE: cqi_value = uci_value.cqi.subband_ue.wideband_cqi; break; } stack->cqi_info(tti, rnti, cqi_cc_idx, cqi_value); } // Precoding Matrix indicator (TM4) if (uci_cfg.cqi.pmi_present) { uint8_t pmi_value = 0; switch (uci_cfg.cqi.type) { case SRSLTE_CQI_TYPE_WIDEBAND: pmi_value = uci_value.cqi.wideband.pmi; break; case SRSLTE_CQI_TYPE_SUBBAND_HL: pmi_value = uci_value.cqi.subband_hl.pmi; break; default: ERROR("CQI type=%d not implemented for PMI\n", uci_cfg.cqi.type); break; } stack->pmi_info(tti, rnti, cqi_cc_idx, pmi_value); } } // Rank indicator (TM3 and TM4) if (uci_cfg.cqi.ri_len) { stack->ri_info(tti, rnti, cqi_cc_idx, uci_value.ri); cqi_scell_info.last_ri = uci_value.ri; } } void phy_ue_db::set_last_ul_tb(uint16_t rnti, uint32_t enb_cc_idx, uint32_t pid, srslte_ra_tb_t tb) { std::lock_guard lock(mutex); // Assert UE DB entry if (_assert_active_enb_cc(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return; } // Save resource allocation ue_db.at(rnti).cell_info[_get_ue_cc_idx(rnti, enb_cc_idx)].last_tb[pid % SRSLTE_FDD_NOF_HARQ] = tb; } srslte_ra_tb_t phy_ue_db::get_last_ul_tb(uint16_t rnti, uint32_t enb_cc_idx, uint32_t pid) const { std::lock_guard lock(mutex); // Assert UE DB entry if (_assert_active_enb_cc(rnti, enb_cc_idx) != SRSLTE_SUCCESS) { return {}; } // Returns the latest stored UL transmission grant return ue_db.at(rnti).cell_info[_get_ue_cc_idx(rnti, enb_cc_idx)].last_tb[pid % SRSLTE_FDD_NOF_HARQ]; }