API-Docs

This is the API-docs for F release o-du/l2.

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

    1. RLC to MAC

      1. Data Transfer(DL) : Transfers DL data to MAC as per Section 9.2.2.1 of the AAD Spec

      2. Buffer Status Reporting(DL) : Reports DL data volume pending in the RLC entity, as per Section 9.2.2.4 of the AAD Spec

    2. MAC to RLC

      1. Data Transfer(UL) : Transfers UL data to RLC as per Section 9.2.2.2 of the AAD Spec

      2. 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

    1. MAC to Scheduler

      1. 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.

      2. Cell Configuration Request : MAC provides SCH the cell configuration as per Section 9.2.3.2.1 of the AAD Spec.

      3. 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.

      4. 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.

      5. 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.

      6. 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.

      7. 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.

      8. 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.

      9. 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.

      10. 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.

      11. 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.

      12. Paging Indication : MAC receives Paging Indication and forwards the trigger to SCH as per Section 9.2.3.2.13 of the AAD Spec.

      13. 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.

      14. 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.

      15. 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.

      16. 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.

    2. Scheduler to MAC

      1. Cell Configuration Response - Response to cell configuration request from MAC, as per Section 9.2.3.3.1 of the AAD Spec.

      2. UE Reconfiguration Response - Response to UE reconfiguration request from MAC, as per Section 9.2.3.3.6 of the AAD Spec.

      3. 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.

      4. 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.

      5. RAR Information - Informs MAC of uplink scheduling and Msg3 scheduling information, as per Section 9.2.3.3.10 of the AAD Spec.

      6. 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.

      7. 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.

      8. UE Delete Response - Response to UE delete request from MAC, as per Section 9.2.3.3.7 of the AAD Spec.

      9. Cell Delete Response - Response to Cell delete request from MAC, as per Section 9.2.3.3.2 of the AAD Spec.

      10. Slice Configuration Response : Response to Slice Configuration request from MAC, as per Section 9.2.3.3.3 of the AAD Spec.

      11. Slice Reconfiguration Response : Response to Slice Reconfiguration request from MAC, as per Section 9.2.3.3.4 of the AAD Spec.

      12. 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.

  3. DU APP - MAC Interface

    • AAD Spec : section 9.2.4

    1. DU APP to MAC

      1. 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.

      2. UE Create Request - Adds UE information at MAC as per Section 9.2.4.3 of the AAD Spec.

      3. UE Reconfiguration Request - Reconfigure UE information for a UE already added at MAC, as per Section 9.2.4.5 of the AAD Spec.

      4. 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.

      5. Cell Stop - Commands MAC to stop cell at L1, as per Section 9.2.4.2 of the AAD spec.

      6. UE Delete Request - Deletes UE information at MAC as per Section 9.2.4.7 of the AAD Spec.

      7. 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.

      8. 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.

      9. 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.

    2. MAC to DU APP

      1. UE Create Response - Response to UE Create Request from DU Manager as per Section 9.2.4.4 of the AAD Spec.

      2. UE Reconfiguration Response - Response to UE Reconfiguration Request from DU APP as per Section 9.2.4.6 of the AAD Spec.

      3. UL-CCCH Indication - Sends the UL CCCH Message received from UE to DU APP as per Section 9.2.4.15 of AAD Spec.

      4. UE Delete Response - Response to UE Delete Request from DU Manager as per Section 9.2.4.8 of the AAD Spec.

      5. 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

    1. DU APP to RLC

      1. UE Create - Adds UE associated RLC entity and related information as per Section 9.2.5.1 of the AAD Spec.

      2. UE Reconfiguration - Reconfigures the UE associated RLC entity previously added at RLC, as per Section 9.2.5.3 of the AAD Spec.

      3. 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.

      4. UE Delete Request - Deletes UE associated RLC entity and related information as per Section 9.2.5.5 of the AAD Spec.

    2. RLC to DU APP

      1. UE Create Response - Response to UE Create Request from DU APP, as per Section 9.2.5.3 of the AAD Spec.

      2. UE Reconfiguration Response - Response to UE Recofiguration Request from DU APP, as per Section 9.2.5.4 of the AAD Spec.

      3. UL RRC Message Tranfer - Delivers RRC Message from UE to CU as per Section 9.2.5.8 of the AAD spec.

      4. 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.

      5. 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

    1. SMO-OAM to DU APP

      1. Cell Configuration - Sends Basic Cell Configurations to DU APP as per Section 9.2.1.1 of the AAD Spec.

      2. 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

    1. DU APP to MAC

      1. Cell Configuration Request - Configures cell information at MAC.

      2. Cell Delete Request - Deletes cell information at MAC.

      3. Slice Configuration Request : Triggers Slice Configuration request once received from O1 towards MAC.

      4. Slice Reconfiguration Request : Triggers Slice Reconfiguration request once received from O1 towards MAC.

    2. MAC to DU APP

      1. Cell Configuration Response - Response to Cell Configuration Request from DU APP

      2. Cell Delete Response - Response to Cell Delet request from DU APP

      3. Slice Configuration Respone : Response to Slice Configuration request from DU Manager.

      4. Slice Reconfiguration Request : Response to Slice Reconfiguration request from DU Manager.

      5. Slot Indication : Indication about the ongoing SFN and Slot information to DU APP.

  2. DU APP - RLC Interface

    1. RLC to DU APP

      1. DL RRC Message Response - Informs DU APP if a DL RRC Message was successfuly processed at RLC and sent to MAC.

      2. Slice Performance Metrics - Sends PM to DU APP every 60sec for every Slice configured.

  3. DU APP - SMO-OAM

    1. Bring cell up - Informs DU to bring a specific cell up

    2. Bring cell down - Informs DU to bring specific cell up

    3. Set the cell operational state - Sets the cell state to ACTIVE/INACTIVE

    4. Raise a cell alarm - Raise an alarm when the cell is ACTIVE/INACTIVE

    5. Slice PM - DU APP sends PM for all Slices in 60sec duration.

  4. MAC - SCH Interface

    1. SCH to MAC

      1. RACH Resource Response : Response to RACH Resource Request for dedicated resource for CF-RA

      2. HARQ Process Release : SCH indicates MAC to release a HARQ process in case a positive acknowledement is received or maximum retransmissions are done already.