.. This work is licensed under a Creative Commons Attribution 4.0 International License. .. http://creativecommons.org/licenses/by/4.0 API-Docs ********** This is the API-docs for G release o-du/l2. .. contents:: :depth: 3 :local: Introduction ----------------- This document lists the APIs implemented between various modules of ODU-High and their functionality. These are in line with ORAN-WG8.AAD-v5.00.00, hereafter referred to as AAD Spec. Note: DU APP module consist functionality related to F1 Handler and O1 Handler API Functions ------------- 1. RLC-MAC Interface - AAD Spec : section 9.2.2 A. RLC to MAC a. Data Transfer(DL) : Transfers DL data to MAC as per Section 9.2.2.1 of the AAD Spec b. Buffer Status Reporting(DL) : Reports DL data volume pending in the RLC entity, as per Section 9.2.2.4 of the AAD Spec B. MAC to RLC a. Data Transfer(UL) : Transfers UL data to RLC as per Section 9.2.2.2 of the AAD Spec b. Schedule Result Reporting (DL) : Reports DL schedule result to RLC as per Section 9.2.2.3 of the AAD Spec 2. MAC-Scheduler Interface - AAD Spec : section 9.2.3 A. MAC to Scheduler a. Air Interface Time : Sends timing information over air interface in terms of SFN and slo, as per Section 9.2.3.1.1 of the AAD Spec. b. Cell Configuration Request : MAC provides SCH the cell configuration as per Section 9.2.3.2.1 of the AAD Spec. c. Add UE Configuration Request : MAC provides SCH the configuration/capabilities of a UE as per Section 9.2.3.2.5 of the AAD Spec. d. Modify UE Reconfiguration Request : MAC provides SCH the re-configuration of UE, also used to add/release/modify existing bearers, as per Section 9.2.3.2.6 of the AAD Spec. e. RACH Indication : MAC receives the RACH Indication and share the contents with SCH as per Section 9.2.3.2.12 of the AAD Spec. f. DL RLC Buffer Status Information : Reports data volume per LC when it is received at MAC as per Section 9.2.3.2.16 of the AAD Spec. g. UL Buffer Status Report Indication : On reception and decoding of received BSR from the UE, MAC provides SCH buffer status report for UL scheduling, as per Section 9.2.3.2.18 of the AAD Spec. h. UE Delete Request : MAC receives UE delete request and forwards the request to SCH as per Section 9.2.3.2.7 of the AAD Spec. i. Cell Delete Request : MAC receives UE delete request and forwards the request to SCH as per Section 9.2.3.2.2 of the AAD Spec. j. Slice Configuration Request : MAC receives Slice Configuration request and forwards the request to SCH as per Section 9.2.3.2.3 of the AAD Spec. k. Slice Reconfiguration Request : MAC receives Slice Reconfiguration request and forwards the request to SCH as per Section 9.2.3.2.4 of the AAD Spec. l. Paging Indication : MAC receives Paging Indication and forwards the trigger to SCH as per Section 9.2.3.2.13 of the AAD Spec. m. RACH Resource Request : MAC receives RACH Resource Request for dedicated RACH resource allocation and forwards to SCH as per Section 9.2.3.2.14 of the AAD Spec. n. RACH Resource Release : MAC receives RACH Resource Release from DU APP and forwards to SCH as per Section 9.2.3.2.15 of the AAD Spec. o. DL HARQ Indication : MAC receives UCI Indication and forwards any DL HARQ feedback from UE to SCH as per Sectiion 9.2.3.2.8 of the AAD spec. p. UL HARQ CRC Indication : MAC receives CRC Indication from PHY and forwards the decoded results to SCH as per Section 9.2.3.2.9 of the AAD Spec. q. Scheduling Request Indication : MAC indicates to scheduler through this API when UE has to be scheduled for uplink grant as per Spec 9.2.3.2.17 of the AAD Spec. B. Scheduler to MAC a. Cell Configuration Response - Response to cell configuration request from MAC, as per Section 9.2.3.3.1 of the AAD Spec. b. UE Reconfiguration Response - Response to UE reconfiguration request from MAC, as per Section 9.2.3.3.6 of the AAD Spec. c. DL Scheduling Information - Provides scheduling information for a given slot for downlink data, as per Section 9.2.3.3.8 of the AAD spec. d. UL Scheduling Information - Provides scheduled information for MAC to form the UL_TTI.request towards O-DU Low, as per Section 9.2.3.3.9 of the AAD Spec. e. RAR Information - Informs MAC of uplink scheduling and Msg3 scheduling information, as per Section 9.2.3.3.10 of the AAD Spec. f. Downlink Control Channel Information - Provides DCI scheduling information for a given slot on PDCCH, as per Section 9.2.3.3.11 of the AAD Spec. g. Downlink Broadcast Allocation - Provides DCI and DL data scheduling information for SIB1 for a given slot for Broadcast Channel, as per Section 9.2.3.3.12 of the AAD Spec. h. UE Delete Response - Response to UE delete request from MAC, as per Section 9.2.3.3.7 of the AAD Spec. i. Cell Delete Response - Response to Cell delete request from MAC, as per Section 9.2.3.3.2 of the AAD Spec. j. Slice Configuration Response : Response to Slice Configuration request from MAC, as per Section 9.2.3.3.3 of the AAD Spec. k. Slice Reconfiguration Response : Response to Slice Reconfiguration request from MAC, as per Section 9.2.3.3.4 of the AAD Spec. l. Downlink Paging Allocation : Provides DCI and DL data scheduling information for any Paging queued for a given slot for Paging Channel, as per Section 9.2.3.3.13 of the AAD Spec. m. Ue Configuration Response : Response to UE reconfiguration request from MAC, as per Section 9.2.3.3.5 of the AAD Spec. 3. DU APP - MAC Interface - AAD Spec : section 9.2.4 A. DU APP to MAC a. Cell Start - Commands MAC to start cell at L1 and to start broadcasting system information, as per Section 9.2.4.1 of the AAD Spec. b. UE Create Request - Adds UE information at MAC as per Section 9.2.4.3 of the AAD Spec. c. UE Reconfiguration Request - Reconfigure UE information for a UE already added at MAC, as per Section 9.2.4.5 of the AAD Spec. d. DL CCCH Indication - Sends DL CCCH Message to MAC to be sent to UE, as per Section 9.2.4.16 of the AAD Spec. e. Cell Stop - Commands MAC to stop cell at L1, as per Section 9.2.4.2 of the AAD spec. f. UE Delete Request - Deletes UE information at MAC as per Section 9.2.4.7 of the AAD Spec. g. DL PCCH Indication - Sends DL PCCH Message to MAC for any Paging scheduled on a slot, as per Section 9.2.4.17 of the AAD Spec. h. RACH Resource Request - Requests for dedicated RACH resources for CF-RA with a UE, as per Section 9.2.4.9 of the AAD Spec. i. RACH Resource Release - Releases dedicated RACH resources allocated for a UE for CF-RA, as per Section 9.2.4.11 of the AAD Spec. B. MAC to DU APP a. UE Create Response - Response to UE Create Request from DU Manager as per Section 9.2.4.4 of the AAD Spec. b. UE Reconfiguration Response - Response to UE Reconfiguration Request from DU APP as per Section 9.2.4.6 of the AAD Spec. c. UL-CCCH Indication - Sends the UL CCCH Message received from UE to DU APP as per Section 9.2.4.15 of AAD Spec. d. UE Delete Response - Response to UE Delete Request from DU Manager as per Section 9.2.4.8 of the AAD Spec. e. RACH Resource Response - Responds with dedicated resources allocated for CF-RA for a UE, as per Section 9.2.4.10 of the AAD Spec. 4. DU APP - RLC Interface - AAD Spec : section 9.2.5 A. DU APP to RLC a. UE Create - Adds UE associated RLC entity and related information as per Section 9.2.5.1 of the AAD Spec. b. UE Reconfiguration - Reconfigures the UE associated RLC entity previously added at RLC, as per Section 9.2.5.3 of the AAD Spec. c. DL RRC Message Transfer - Requests RLC to deliver RRC message from CU to the UE, as per Section 9.2.5.7 of the AAD Spec. d. UE Delete Request - Deletes UE associated RLC entity and related information as per Section 9.2.5.5 of the AAD Spec. B. RLC to DU APP a. UE Create Response - Response to UE Create Request from DU APP, as per Section 9.2.5.2 of the AAD Spec. b. UE Reconfiguration Response - Response to UE Recofiguration Request from DU APP, as per Section 9.2.5.4 of the AAD Spec. c. UL RRC Message Tranfer - Delivers RRC Message from UE to CU as per Section 9.2.5.8 of the AAD spec. d. RRC Message Delivery Report - Informs DU Manager on failed/successful delivery of a DL RRC message to UE, as per Section 9.2.5.9 of the AAD Spec. e. UE Delete Response - Response to UE Delete Request from DU APP, as per section 9.2.5.6 of the AAD Spec. 5. SMO-OAM - DU APP - AAD Spec: Section 9.2.1 A. SMO-OAM to DU APP a. Cell Configuration - Sends Basic Cell Configurations to DU APP as per Section 9.2.1.1 of the AAD Spec. b. Slice Configuration - Sends Slice Configurations to DU APP as per Section 9.2.1.2 of the AAD Spec. Additional APIs ---------------- 1. DU APP - MAC Interface A. DU APP to MAC a. Cell Configuration Request - Configures cell information at MAC. b. Cell Delete Request - Deletes cell information at MAC. c. Slice Configuration Request : Triggers Slice Configuration request once received from O1 towards MAC. d. Slice Reconfiguration Request : Triggers Slice Reconfiguration request once received from O1 towards MAC. B. MAC to DU APP a. Cell Configuration Response - Response to Cell Configuration Request from DU APP b. Cell Delete Response - Response to Cell Delet request from DU APP c. Slice Configuration Respone : Response to Slice Configuration request from DU Manager. d. Slice Reconfiguration Request : Response to Slice Reconfiguration request from DU Manager. e. Slot Indication : Indication about the ongoing SFN and Slot information to DU APP. 2. DU APP - RLC Interface A. RLC to DU APP a. DL RRC Message Response - Informs DU APP if a DL RRC Message was successfuly processed at RLC and sent to MAC. b. Slice Performance Metrics - Sends PM to DU APP every 60sec for every Slice configured. 3. DU APP - SMO-OAM a. Bring cell up - Informs DU to bring a specific cell up b. Bring cell down - Informs DU to bring specific cell up c. Set the cell operational state - Sets the cell state to ACTIVE/INACTIVE d. Raise a cell alarm - Raise an alarm when the cell is ACTIVE/INACTIVE e. Slice PM - DU APP sends PM for all Slices in 60sec duration. 4. MAC - SCH Interface A. SCH to MAC a. RACH Resource Response : Response to RACH Resource Request for dedicated resource for CF-RA b. HARQ Process Release : SCH indicates MAC to release a HARQ process in case a positive acknowledement is received or maximum retransmissions are done already.