1. Introduction¶
This document specifies the E2 capabilities of the Accelleran dRAX RIC. We specify the versions of E2 that are supported, as well as the functionalities per E2 Service Model (SM).
Difference between dRAX RIC and dRAX RAN E2 capabilities
This documentation relates to the dRAX RIC E2 capabilities. E2 capabilities of the Accelleran RAN (such as the DU) are documented in the dRAX RAN Documentation. There can be capabilities that the dRAX RIC supports but that are not yet supported by the Accelleran RAN.
1.1 dRAX RIC E2 Architecture¶
We have chosen to take the ORAN xApp SDK approach of handling E2 in the Accelleran dRAX RIC. This means that the RIC contains a component named E2 Broker which handles all the E2 interactions to the RAN. The xApps communicate to the E2 Broker by using the abstraction in the xApp SDK. The E2 Broker is the component that then does the ASN.1 encoding and sends the message over the E2 protocol to the RAN. Likewise, when the RAN sends E2 messages, the E2 Broker does the ASN.1 decoding, and forwards the messages to the xApps. xApps again can use xApp SDK abstractions to read the messages.
This architecture allows xApp Developer to easily create xApps that use the E2 protocol, as they don't have to worry about ASN.1 encoding/decoding themselves, but rather use high-level abstractions in the xApp SDK. The remainder of this document covers the E2 abstractions in the Accelleran xApp SDK, detailing how they can be used and giving examples.
1.2 Supported E2 Versions¶
The E2 Broker in the Accelleran dRAX RIC supports the following E2 versions:
- O-RAN.WG3.E2AP-R003-v05.00
- O-RAN.WG3.E2SM-R003-v05.00
- O-RAN.WG3.E2SM-KPM-R003-v05.00
- O-RAN.WG3.E2SM-RC-R003-v06.00
- O-RAN.WG3.E2SM-CCC-R003-v04.00
1.3 Functionalities Supported¶
The RIC E2 Broker supports the following functionalities from E2 AP and E2 KPM Service models.
- E2 SETUP REQUEST
- E2 SETUP RESPONSE
- E2 SETUP FAILURE
- RIC SUBSCRIPTION REQUEST
- RIC SUBSCRIPTION RESPONSE
- RIC SUBSCRIPTION DELETE REQUEST
- RIC SUBSCRIPTION DELETE RESPONSE
- RIC INDICATION
- RIC CONTROL REQUEST
- RIC CONTROL ACKNOWLEDGE
1.4 KPM Service Model¶
E2 KPM service model can support both cell, slice level KPIs.
1.4.1 Summary of E2 KPM SM IE Formats Defined to Support RIC Event Trigger Styles¶
| RIC Event Trigger Style | Event Trigger Definition Format |
|---|---|
| Style 1 | 1 |
1.4.2 Summary of E2 KPM SM IE Formats Defined to Support RIC Service Styles¶
| RIC Service Style | Action Definition Format | Indication Header Format | Indication Message Format | Call Process ID Format | Control Header Format | Control Message Format | Control Outcome Format |
|---|---|---|---|---|---|---|---|
| REPORT Style 1 | 1 | 1 | 1 | 1 | - | - | - |
| REPORT Style 2 | 2 | 1 | 1 | 1 | - | - | - |
| REPORT Style 3 | 3 | 1 | 2 | - | - | - | - |
1.5 RC Service Model¶
1.5.1 Subscription message¶
Supported Event Trigger Definition Formats:
- 2
- 3
Supported Action Definition Formats: - 1 - 2
1.5.2 Unsubscribe message¶
This message is fully supported
1.5.3 Indication message¶
Supported Report Styles:
- 1
- 2
- 3
1.5.4 Control message¶
Supported RIC Control Message Formats:
- 1
1.5.5 Control Acknowledge¶
This message is fully supported
1.6 CCC Service Model¶
All service styles and message formats specified in [O-RAN.WG3.E2SM-CCC-R003-v04.00] are supported.
JSON encoding
The E2 SM CCC uses the JSON encoding rather than ASN.1.