**Table of Contents** 1. [OpenAirInterface eNB Feature Set](#openairinterface-enb-feature-set) 1. [eNB PHY Layer](#enb-phy-layer) 2. [eNB MAC Layer](#enb-mac-layer) 3. [eNB RLC Layer](#enb-rlc-layer) 4. [eNB PDCP Layer](#enb-pdcp-layer) 5. [eNB RRC Layer](#enb-rrc-layer) 6. [eNB X2AP](#enb-x2ap) 7. [eNB Advanced Features](#enb-advanced-features) 2. [OpenAirInterface Functional Split](#openairinterface-functional-split) 3. [OpenAirInterface UE Feature Set](#openairinterface-ue-feature-set) 1. [LTE UE PHY Layer](#lte-ue-phy-layer) 2. [LTE UE MAC Layer](#lte-ue-mac-layer) 3. [LTE UE RLC Layer](#lte-ue-rlc-layer) 4. [LTE UE PDCP Layer](#lte-ue-pdcp-layer) 5. [LTE UE RRC Layer](#lte-ue-rrc-layer) # OpenAirInterface Block diagram # ![Block Diagram](./images/oai_enb_block_diagram.png) # OpenAirInterface eNB Feature Set # ## eNB PHY Layer ## The Physical layer implements **3GPP 36.211**, **36.212**, **36.213** and provides the following features: - LTE release 8.6 compliant, and implements a subset of release 10 - FDD and TDD configurations: 1 (experimental) and 3 - Bandwidth: 5, 10, and 20 MHz - Transmission modes: 1, 2 (stable), 3, 4, 5, 6, 7 (experimental) - Max number of antennas: 2 - CQI/PMI reporting: aperiodic, feedback mode 3 - 0 and 3 - 1 - PRACH preamble format 0 - Downlink (DL) channels are supported: PSS, SSS, PBCH, PCFICH, PHICH, PDCCH, PDSCH, PMCH, MPDCCH - Uplink (UL) channels are supported: PRACH, PUSCH, PUCCH (format 1/1a/1b), SRS, DRS - HARQ support (UL and DL) - Highly optimized base band processing (including turbo decoder) - Multi-RRU support: over the air synchro b/ multi RRU in TDD mode - Support for CE-modeA for LTE-M. Limited support for repeatition, single-LTE-M connection, legacy-LTE UE attach is disabled. ### Performances ### **Transmission Mode, Bandwidth** | **Expected Throughput** | **Measured Throughput** | **Measurement Conditions** -------------------------------- | ----------------------- | ------------------------| ----------------: FDD DL: 5 MHz, 25 PRBS/ MCS 28 | 16 - 17 Mbit/s | TM1: 17.0 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) FDD DL: 10 MHz, 50 PRBS/ MCS 28 | 34 - 35 Mbit/s | TM1: 34.0 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) FDD DL: 20 MHz, 100 PRBS/ MCS 28 | 70 Mbit/s | TM1: 69.9 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) | | | FDD UL: 5 MHz, 25 PRBS/ MCS 20 | 9 Mbit/s | TM1: 8.28 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) FDD UL: 10 MHz, 50 PRBS/ MCS 20 | 17 Mbit/s | TM1: 18.3 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) FDD UL: 20 MHz, 100 PRBS/ MCS 20 | 35 Mbit/s | TM1: 18.6 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) | | TDD DL: 5 MHz, 25 PRBS/ MCS **XX** | 6.5 Mbit/s | TM1: 6.71 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) TDD DL: 10 MHz, 50 PRBS/ MCS **XX** | 13.5 Mbit/s | TM1: 13.6 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) TDD DL: 20 MHz, 100 PRBS/ MCS **XX** | 28.0 Mbit/s | TM1: 27.2 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) | | | TDD UL: 5 MHz, 25 PRBS/ MCS **XX** | 2.0 Mbit/s | TM1: 3.31 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) TDD UL: 10 MHz, 50 PRBS/ MCS **XX** | 2.0 Mbit/s | TM1: 7.25 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) TDD UL: 20 MHz, 100 PRBS/ MCS **XX** | 3.0 Mbit/s | TM1: 4.21 Mbits/s | COTS-UE Cat 4 (150/50 Mbps) ### Number of supported UEs ### * 16 by default * up to 256 when compiling with dedicated compile flag * was tested with 40 COTS-UE ## eNB MAC Layer ## The MAC layer implements a subset of the **3GPP 36.321** release v8.6 in support of BCH, DLSCH, RACH, and ULSCH channels. - RRC interface for CCCH, DCCH, and DTCH - Proportional fair scheduler (round robin scheduler soon) - DCI generation - HARQ Support - RA procedures and RNTI management - RLC interface (AM, UM) - UL power control - Link adaptation - Connected DRX (CDRX) support for FDD LTE UE. Compatible with R13 from 3GPP. Support for Cat-M1 UE comming soon. ## eNB RLC Layer ## The RLC layer implements a full specification of the 3GPP 36.322 release v9.3. - RLC TM (mainly used for BCCH and CCCH) * Neither segment nor concatenate RLC SDUs * Do not include a RLC header in the RLC PDU * Delivery of received RLC PDUs to upper layers - RLC UM (mainly used for DTCH) * Segment or concatenate RLC SDUs according to the TB size selected by MAC * Include a RLC header in the RLC PDU * Duplication detection * PDU reordering and reassembly - RLC AM, compatible with 9.3 * Segmentation, re-segmentation, concatenation, and reassembly * Padding * Data transfer to the user * RLC PDU retransmission in support of error control and correction * Generation of data/control PDUs ## eNB PDCP Layer ## The current PDCP layer is header compliant with **3GPP 36.323** Rel 10.1.0 and implements the following functions: - User and control data transfer - Sequence number management - RB association with PDCP entity - PDCP entity association with one or two RLC entities - Integrity check and encryption using the AES and Snow3G algorithms ## eNB RRC Layer ## The RRC layer is based on **3GPP 36.331** v14.3.0 and implements the following functions: - System Information broadcast (SIB 1, 2, 3, and 13) * SIB1: Up to 6 PLMN IDs broadcast - RRC connection establishment - RRC connection reconfiguration (addition and removal of radio bearers, connection release) - RRC connection release - RRC connection re-establishment - Inter-frequency measurement collection and reporting (experimental) - eMBMS for multicast and broadcast (experimental) - Handover (experimental) - Paging (soon) - RRC inactivity timer (release of UE after a period of data inactivity) ## eNB X2AP ## The X2AP layer is based on **3GPP 36.423** v14.6.0 and implements the following functions: - X2 Setup Request - X2 Setup Response - X2 Setup Failure - Handover Request - Handover Request Acknowledge - UE Context Release - X2 timers (t_reloc_prep, tx2_reloc_overall) - Handover Cancel - X2-U interface implemented ## eNB Advanced Features ## **To be completed** # OpenAirInterface Functional Split # - RCC: Radio-Cloud Center - RAU: Radio-Access Unit - RRU: Remote Radio-Unit ![Functional Split Architecture](./images/oai_lte_enb_func_split_arch.png) - IF4.5 / IF5 : similar to IEEE P1914.1 - FAPI (IF2) : specified by Small Cell Forum (open-nFAPI implementation) - IF1 : F1 in 3GPP Release 15 (not implemented yet) # OpenAirInterface UE Feature Set # ## LTE UE PHY Layer ## The Physical layer implements **3GPP 36.211**, **36.212**, **36.213** and provides the following features: - LTE release 8.6 compliant, and implements a subset of release 10 - FDD and TDD configurations: 1 (experimental) and 3 - Bandwidth: 5, 10, and 20 MHz - Transmission modes: 1, 2 (stable) - Max number of antennas: 2 - CQI/PMI reporting: aperiodic, feedback mode 3 - 0 and 3 - 1 - PRACH preamble format 0 - All downlink (DL) channels are supported: PSS, SSS, PBCH, PCFICH, PHICH, PDCCH, PDSCH, PMCH - All uplink (UL) channels are supported: PRACH, PUSCH, PUCCH (format 1/1a/1b), SRS, DRS - LTE MBMS-dedicated cell (feMBMS) procedures subset for LTE release 14 (experimental) - LTE non-MBSFN subframe (feMBMS) Carrier Adquistion Subframe-CAS procedures (PSS/SSS/PBCH/PDSH) (experimental) - LTE MBSFN MBSFN subframe channel (feMBMS): PMCH (CS@1.25KHz) (channel estimation for 25MHz bandwidth) (experimental) ## LTE UE MAC Layer ## The MAC layer implements a subset of the **3GPP 36.321** release v8.6 in support of BCH, DLSCH, RACH, and ULSCH channels. - RRC interface for CCCH, DCCH, and DTCH - HARQ Support - RA procedures and RNTI management - RLC interface (AM, UM) - UL power control - Link adaptation - MBMS-dedicated cell (feMBMS) RRC interface for BCCH - eMBMS and MBMS-dedicated cell (feMBMS) RRC interface for MCCH, MTCH ## LTE UE RLC Layer ## The RLC layer implements a full specification of the 3GPP 36.322 release v9.3. ## LTE UE PDCP Layer ## The current PDCP layer is header compliant with **3GPP 36.323** Rel 10.1.0. ## LTE UE RRC Layer ## The RRC layer is based on **3GPP 36.331** v14.3.0 and implements the following functions: - System Information decoding - RRC connection establishment - MBMS-dedicated cell (feMBMS) SI-MBMS/SIB1-MBMS management ## LTE UE NAS Layer ## The NAS layer is based on **3GPP 24.301** and implements the following functions: - EMM attach/detach, authentication, tracking area update, and more - ESM default/dedicated bearer, PDN connectivity, and more [oai wiki home](https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/home) [oai softmodem build procedure](BUILD.md) [running the oai softmodem ](RUNMODEM.md)