# Daily Note 30/07/2020
###### tags: `Daily Notes` , `O-RAN` , `Acumos`
## Name : Christofel Rio Goenawan
## University : Bandung Institute of Technology (ITB)
---
## Schedule:
1. Study Detailed Works of Communication of E2 Interfaces and Near- RT RIC.
2. Study Relationship Between RIC Services and E2AP Procedures.
3. Continue to try installing Acumos AI in NTUST Server.
## Outcome :
## Further Plan :
- Continue to deploy Acumos AIO in NTUST server
- Study more detailed about AIO Installation in Kubernets
---
## Daily Log
### 1.Study Detailed Works of Communication of E2 Interfaces and Near- RT RIC. <mark>(9.00)</mark>
- Study more detail explanation in [Documentation](https://wiki.o-ran-sc.org/pages/viewpage.action?pageId=3604819 ) and other sources.
### 2. Study Relationship Between RIC Services and E2AP Procedures. <mark></mark>
- Study more detail explanation in [Documentation](https://www.o-ran.org/s/ORAN-WG3E2SM-KPM-v0100.docx) and other sources.
### 3.Continue to try deploying Acumos AIO in NTUST server. <mark></mark>
- Continue to try to deploy Acumos AIO in NTUST server using Prep- Deploy Process based one previous [study notes](https://hackmd.io/@christofel04/TEEP_Daily_Notes_10_7_2020).
---
## Report
### 1. Communication of E2 Interfaces and Near- RT RIC.
>In this note Writer use [Documentation](https://www.o-ran.org/s/ORAN-WG3E2GAP-v0100.docx) and [Ferlinda's Notes](https://hackmd.io/@ferlinda/S1F1k_Z1w) as study sources.
#### Near- RT RIC Architectures
From reference, Near- RT RIC architectures simple scheme can be seen as below.

#### Function of E2 interface, E2 nodes, and E2AP in communication between Near-RT RIC
From Ferlinda's Notes, the works of E2 Interfaces on Near- RT RIC communication can be explained as below.
- From scheme above we can see that Near-RT RIC consisted of Database. This database holds data from **xApp applications** and **E2 Node**, it provides data to xApp applications.
- In information exchange, E2 interface acted as a mean **to provide connectivity between Near-RT RIC and E2 Node** (which might be supplied by different vendors).
- E2 interface facilitate the exposure of selected E2 Node data (network measurements, context information, etc.) to the Near-RT RIC, it also enables the Near-RT RIC to control selected functions on the E2 Node. The diagram can be seen as below.

- E2AP is a part of E2 interface, this functional procedures module contains procedures used to **pass application specific messages between Near-RT RIC application and a target function in an E2 node** (RAN Function will be explained).
:::info
The Example message flow to gNB/eNB is illustrated on [**here**](https://hackmd.io/@ferlinda/rkcdeVxkw)
:::
#### E2 Indication Report Example
From reference the E2 indication report example can be seen as below.

#### What is Being Sent Between Near-RT RIC and E2 Node?
From Ferlinda's notes the data sent between Near- RT RIC and E2 node can be seen as below.
- Near-RT RIC uses a RIC Subscription procedure to request that E2 Node sends a:
- **Report** message to Near-RT RIC and the associated procedure continues in E2 Node after each occurrence of a defined RIC Subscription procedure Event Trigger.
- **Insert** message to Near-RT RIC and suspends the associated procedure in E2 Node after each occurrence of a defined RIC Subscription procedure Event Trigger.
- Near-RT RIC sends a:
- **Control** message to E2 Node to initiate a new associated procedure or resume a previously suspended associated procedure in the E2 Node.
- Near-RT RIC requests that E2 Node executes a specific:
- **Policy** during functioning of the E2 Node after each occurrence of a defined RIC Subscription procedure Event Trigger.
### Relationship Between RIC Services and E2AP Procedures
---
### 2. Relationship Between RIC Services and E2AP Procedures
>In this note Writer use [Documentation](https://wiki.o-ran-sc.org/display/RICNR/Release+A) as study sources.
#### Function of E2AP RIC Services Components
From reference the function of E2AP RIC Services components can be seen as below.
|E2AP RIC Services|Function|
|---|---|
|E2AP RIC Subscription procedure|install Event Trigger and Actions corresponding to RIC services REPORT, INSERT and/or POLICY|
|E2AP RIC Indication procedure|carry outcome of RIC services REPORT and INSERT |
|RIC Control procedure|initiate RIC service CONTROL |
#### What is the relationship between RIC Services and E2AP Procedures?
From reference, the relationshop between RIC Services and E2AP Procesures can be seen as below.

:::info
RIC Services may be combined **within a common subscription (e.g. POLICY then REPORT, REPORT then REPORT)** or **as a sequence of RIC Services (e.g. REPORT followed by POLICY, INSERT followed by CONTROL, REPORT followed by CONTROL)**.
:::
#### What is RAN Function?
E2 interface is used to **carry RAN Function specific messages between a given RAN Function and Near-RT RIC**.
A given RAN Function offers a set of services to be exposed over the E2 (report , insert , control , and/ or policy ) using E2AP defined procedures. Each of the E2AP Procedures contains specific E2 Node RAN Function dependent **Information Elements (IEs)**.
With E2AP Information Element Reference explained in **[here](https://www.o-ran.org/s/ORAN-WG3E2SM-KPM-v0100.docx)**.
From Ferlinda's notes RAN Function can be seen as below.
|RAN Function|Detail|
|---|---|
|RAN Function definition|Defines the RAN Function Name and describes the E2 services that the specific RAN Function is currently configured to present over the E2 interface.|
|RIC Event Trigger Definition approach|Describes the approach to be used in Near-RT RIC Subscription messages to set Near-RT RIC Event Trigger Definition in the RAN Function.|
|RIC Action Definition approach|Describes the approach to be used in subsequent Near-RT RIC Subscription messages to set required sequence of Near-RT RIC Action in the RAN Function. |
|RIC Indication header and RIC Indication message approach|RIC Indication header and RIC Indication message approach.|
|RIC Control header and RIC Control message approach|Describes the approach to be used by Near-RT RIC when composing CONTROL messages.|
|RAN Function Policies|Describes the set of policies that the RAN Function is configured to support and the corresponding Parameters that may be used to configure the policy using Near-RT RIC POLICY services.|
---
### 3. Continue to try deploying Acumos AIO in NTUST server
>In this note Writer use [Previous Notes](https://hackmd.io/@christofel04/TEEP_Daily_Notes_10_7_2020) as study sources.
:::warning
After I discussed with Kevin, the problem is because **there are another K8s Cluster using that port**. After uninstall the old Cluster, the problem solved.
:::
:::info
**Next Writer Will Continue to Install Acumos AIO in NTUST Server**
:::
---
## Reference
1. https://www.o-ran.org/s/ORAN-WG3E2GAP-v0100.docx
2. https://www.o-ran.org/s/ORAN-WG3E2SM-KPM-v0100.docx
3. https://docs.o-ran-sc.org/en/latest/architecture/architecture.html
4. https://docs.acumos.org/en/clio/submodules/system-integration/docs/oneclick-deploy/user-guide.html