＠NTUST, Taiwan
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# Internship Notes By Anna
###### tags: `Internship`
_________________________
##### [<center>Root Page</center>](https://hackmd.io/1vzAzkNgRdy-M68AKvg_TA?view)[<center>Background Knowledge Progress</center>](https://hackmd.io/lOBW-F2JT_q_3g9XvW2kXg?view=) [<center>Daily Report</center>](https://hackmd.io/GaVfvzF3QUK0mOKC6Jne4A?view=)
>Name: Anna Ogorodnyk
>E-mail: [e-mail]
>HackMD: @ydt688
>Target Topic: RIC
_________________________
##### <center>Minutes of Meeting (MoM)</center>
**Team meetings:**
* [1st Introductory RIC Team Meeting (22/06/21)](https://hackmd.io/O50layg2RwGbuYukYq_d2A?view=)
* [2nd RIC Team Meeting (22/06/28)](https://hackmd.io/rT7-birnQICFthDHVbpzig?view=)
* [3rd RIC Team Meeting (22/07/05)](https://hackmd.io/V9TG1wMqSPCGPtIjl10gsw?view=)
* [4th RIC Team Meeting (22/07/12)](https://hackmd.io/MUjwwOVxRgmEcxjq0PuqUA?view=)
* [5th RIC Team Meeting (22/07/19)](https://hackmd.io/O5UbT9SYRZGPerTq-BDFbw?view=)
* 6th RIC Team Meeting - Missed
* [7th RIC Team Meeting (22/08/02)](https://hackmd.io/_rbvAk6USDW3cOWchR4AHw?view=)
* 8th RIC Team Meeting - Missed
* [9th RIC Team Meeting (22/08/23)](https://hackmd.io/IrOrLjVzQm6Da213OyD5Sw?view)
_________________________

### Week 01: Background of O-RAN
- Fundamentals: Introduction to O-RAN and its components ([2022/04/28](https://hackmd.io/FLz2K2wYQ8qWI2H-N4bhAw?view=))
- Fundamentals: FlexRIC architecture ([2022/04/29](https://hackmd.io/McIeIBnWRz--6O9ioeB8GA?view=))
- Fundamentals: O-RAN use cases ([2022/04/30](https://hackmd.io/F1om7E_kTau4X3tbJ-mHqQ?view=))

:::success
**Goals**
- [x] Study the [background of O-RAN](https://arxiv.org/pdf/2202.01032.pdf) and its components, including RIC.
- [x] Study [FlexRIC architecture](https://www.eurecom.fr/publication/6737/download/comsys-publi-6737.pdf).
- [x] Learn more about [O-RAN use cases](https://static1.squarespace.com/static/5ad774cce74940d7115044b0/t/5e95a0a306c6ab2d1cbca4d3/1586864301196/O-RAN+Use+Cases+and+Deployment+Scenarios+Whitepaper+February+2020.pdf) and xApps.

\
**What I have learned**

* An introduction to the background and architecture of O-RAN
* Basic understanding of O-RAN use cases, common xApps and service models
* FlexRIC functions and architecture
:::

### Week 02: FlexRIC Agent source code
- FlexRIC: Building using Gentoo Linux ([2022/05/02](https://hackmd.io/kogf4pRWTmSgk2jFMcwZ5g?view=))
- FlexRIC: Source code [structure](https://openairinterface.org/wp-content/uploads/2021/12/Lab1.pdf) ([2022/05/03~04](https://hackmd.io/8q6b52TRQuCp-3caB2qS7Q?view=))
- FlexRIC: Agent implementation ([2022/05/05](https://hackmd.io/69m_bUtkR76kExxteiudfg?view=))

:::success
**Goals**

- [x] Build FlexRIC.
- [x] Explore FlexRIC project structure.
- [x] Study how FlexRIC Agent functions are [implemented in each file](https://gitlab.eurecom.fr/mosaic5g/flexric/-/tree/master/src/agent).

\
**What I have learned**

* Installation of dependencies of FlexRIC and building it
* FlexRIC source code structure and three main modules
* Agent implementation and relations between files
:::

### Week 03: FlexRIC Library and RIC source code
- FlexRIC: Library implementation ([2022/05/10](https://hackmd.io/LlaDt_O3Ro2wTOA4ZEXWYA?view=))
- FlexRIC: RIC implementation ([2022/05/11~12](https://hackmd.io/NF-nrHe8Tdmutw5fqzQCDA?view=))
- FlexRIC: Summary
- Summary notes ([2022/05/13](https://hackmd.io/s8C3SsSVS3eUI6d9RVSFCQ?view=))
- Implementation diagram ([2022/05/14](https://hackmd.io/L54F5g7PRFa77ylA4Cyb3w?view=))
- Testing with Wireshark ([2022/05/15](https://hackmd.io/5hv0ehjNR6SaRP4CAbXYIg?view=))

:::success
**Goals**

- [x] Study how [FlexRIC Library](https://gitlab.eurecom.fr/mosaic5g/flexric/-/tree/master/src/lib) is implemented.
- [x] Study how [RIC](https://gitlab.eurecom.fr/mosaic5g/flexric/-/tree/master/src/ric) is implemented.
- [x] Create a block diagram of FlexRIC structure to summarize.
- [x] Test FlexRIC with Wireshark.

\
**What I have learned**
* An understanding of Near-RIC and Library implementation and purpose
* An understanding of FlexRIC usage
:::

### Week 04: E2 Messages
- E2 Messages: FlexRIC E2 Protocol Abstraction ([2022/05/19](https://hackmd.io/giHZ4QLlSZqhibgY9mhUlA?view=))

:::success
**Goals**

- [x] Overview [E2 Protocol Abstraction](https://www.eurecom.fr/publication/6737/download/comsys-publi-6737.pdf) of FlexRIC
- [x] Overview ASN.1 PER E2AP [encoding/decoding algorithms](https://gitlab.eurecom.fr/mosaic5g/flexric/-/tree/master/src/lib/ap) in FlexRIC implementation

\
**What I have learned**
* An understanding of the levels of E2 protocol abstraction of FlexRIC
:::

___

## Summer Intern starting :sun_with_face:

### Week 05:
- Controller Specialization: Overview ([2022/06/24](https://hackmd.io/lE7njRDAQni-KwPIGRrg9A?view=))

:::success
**Goals**

- [x] Understand the methods of [controller specialization](https://m.facebook.com/watch/?v=951988102412509&_rdr)
- [x] Present FlexRIC architecture

\
**What I have learned**
* An understanding of controller specialization methods
:::

### Week 06:
- Controller Specialization: Adding Service Models in FlexRIC ([2022/06/27](https://hackmd.io/2nt6pysPS92yQVxmbUrO2g?view=))
- Controller Specialization: Tracing FlexRIC iApp and xApp NNG code ([2022/06/28~29](https://hackmd.io/Fib0bqLlSxGPUzu9bmiYRQ?view=))
- FlexRIC Architecture: Components Interconnection ([2022/06/30](https://hackmd.io/DMsyADIiSo-yYSSX6MXkOg?view=))
- Controller Specialization: SWIG python wrapper for the RIC ([2022/07/01](https://hackmd.io/34ZXCzbtTu6AhhjzWVsgpw?view=))

:::success
**Goals**

- [x] Trace iApp and xApp code in FlexRIC to understand the architecture
- [x] Understand the difference between xApps and SM
- [x] Find a way of writing xApps
- [x] Understand FlexRIC and physical components interconnection

**What I have learned**
* An understanding of xApps communication interface
* FlexRIC components interconnection
* Building SWIG FlexRIC python wrapper to test CLI interface
:::

### Week 07:
- E2 message flow in FlexRIC ([2022/07/04~05](https://hackmd.io/VK-UJQfYTmaPbxRTgtBQVA?view=))
- Fix Agent to E2 Node connection diagrams ([2022/07/05](https://hackmd.io/IYtmos0eRqSiakt0nK0pSg?view=))
- iApp and xApp control flow ([2022/07/06](https://hackmd.io/wicrrRlRTBqOjzH_ITIwEw?view=))
- Study RAN Internals ([2022/07/07~08](https://hackmd.io/b-P1g6lxQBm_HWeKjUOqYQ?view=))
- Setup [SSH connection to VM](https://hackmd.io/@Yueh-Huan/r1Ti7Y0cq) over Wireguard ([2022/07/08](https://hackmd.io/GCpwUxywQ4e0DUWijIPIjA?view=))

:::success
**Goals**

- [x] Understand how FlexRIC implements e2 message flow
- [x] Understand how iApps receive messages from xApps, and when xApps disconnect
- [x] Study [RAN Internals](https://5g.systemsapproach.org/ran.html)

**What I have learned**
- Communication interface between iApp and xApp
- A basic understanding of 5G architecture and RAN internals
- E2 message flow implementation in FlexRIC
:::

### Week 08:
- Integrating OAI RF Simulated gNB and FlexRIC on VM server ([2022/07/11](https://hackmd.io/-wtJoR_RRsW8Z9uLDQ_JAw?view=))
- RAN functions which MAC SM can control ([2022/07/13](https://hackmd.io/YU3C-LaiSWqxlaz98DR2yw?view=))
- Near-RT RIC & O-DU Course - Part 1 ([2022/07/13](https://hackmd.io/ZUqM-F36R-CKULu6piuJoA?view=))
- Near-RT RIC & O-DU Course - Part 2 ([2022/07/14](https://hackmd.io/N1v2r3TWRtK15KI9jb1QnQ?view=))
- Components interconnection for installing OAI gNB with USRP ([2022/07/15](https://hackmd.io/ArCaqSKhSSCKAFcHSDa6aw?view=))

:::success
**Goals**

- [x] Integrate OAI gNB and FlexRIC on VM server
- [x] Take the Near-RT RIC & O-DU Course
- [x] Overview the architecture for [installing OAI gNB with USRP](https://gitlab.eurecom.fr/oai/openairinterface5g/-/blob/NR_SA_Tutorials_v2/doc/NR_SA_CN5G_gNB_B210_COTS_UE_Tutorial.md) and integrating with FlexRIC
- [x] Understand the RAN functions that MAC SM can support

**What I have learned**
- Deploy and integrate OAI gNB and FlexRIC
- Understand OSC Near-RT RIC Platform and xApps LCM
- Understand basics of O-DU Architecture and OSC O-DU Implementation
- Overview OAI gNB installation with USRP
:::

### Week 09:
- Comparison of FlexRIC to O-RAN RIC Platform ([2022/07/18](https://hackmd.io/xHULpjPjSda-1cZrjY4LHg?view=))
- Mapping FlexRIC Architecture diagram to implementation files ([2022/07/19](https://hackmd.io/CEJGgaoGSxGIqveMcLxWpg?view=))
- Using Wireshark to see the E2 Message Flow ([2022/07/19](https://hackmd.io/58t4Jcv_QlyHKL30PeXrYw?view=))
- Sorting notes and preparing a presentation for FlexRIC demonstration ([2022/07/20~21](https://hackmd.io/S5D2CTbfSN-qgS17O5CDUA?view=))

:::success
**Goals**

- [x] Compare FlexRIC to O-RAN specification
- [x] Map the blocks of Agent and RIC Architecture diagram to the files and functions of their implementation
- [x] Using Wireshark to see the [E2 Message Flow](https://www.wireshark.org/docs/dfref/e/e2ap.html)
- [x] Sort notes and prepare a presentation for FlexRIC demonstration

**What I have learned**
- Difference between OAI FlexRIC and OSC RIC
- E2 Message Flow by Wireshark
:::

### Week 10:
- Overviewing FlexRIC `dev` branch ([2022/07/25](https://hackmd.io/Oo-T1AOwScWa1aA6HFWx7A?view=))
- Sample xApp creation steps ([2022/07/27](https://hackmd.io/hfwl6QTITie3sQlBYviE8g?view=))
- Slicing xApp ([2022/07/27](https://hackmd.io/2NIr9n9VSFm-K1UXnL7a4A?view=))
- E2SM MAC, Slice, PDCP, RLC, and TC implementation details ([2022/07/28~29](https://hackmd.io/38XgXL-tRgGENF19WUf5Iw?view=))

:::success
**Goals**

- [x] Overview FlexRIC [`dev` branch](https://gitlab.eurecom.fr/mosaic5g/flexric/-/tree/dev/)
- [x] Study xApp for [MAC/RLC/PDCP monitoring](https://gitlab.eurecom.fr/mosaic5g/flexric/-/blob/dev/test/xApp/c/monitor/xapp_mac_rlc_pdcp_moni.c)
- [x] Study xApp for [Slice control](https://gitlab.eurecom.fr/mosaic5g/flexric/-/blob/dev/test/xApp/c/slice/xapp_slice_moni_ctrl.c)
- [x] Learn more detail about E2SM MAC (Highest Priority), Slice, PDCP, RLC, and TC

**What I have learned**
- A brief overview of FlexRIC unstable version updates
- An understanding of FlexRIC SM, including MAC, RLC, PDCP, Slice and TC SM in greater detail
- Newly introduced xApp API and sample xApps for metrics monitor and slice control
- A method of writing xApps
:::

### Week 11:
- Traffic Contol SM xApps ([2022/08/01~03](https://hackmd.io/OuqP7YtOQb-o9BtOTnCFUg?view=))
- Fix previous week notes according to Yueh-Huan [suggestions](https://hackmd.io/_rbvAk6USDW3cOWchR4AHw?view=#Important-points) ([2022/08/02](https://hackmd.io/_rbvAk6USDW3cOWchR4AHw?view=#Important-points))
- FlexRIC deployment guide ([2022/08/04](https://hackmd.io/w5cIoIXJRn6opzViZjs3MQ?view=))
- xApp API & E42 iApp ([2022/08/05](https://hackmd.io/-KG_6O59QtaGl4RQr9s6Mg?view=))

:::success
**Goals**
- [x] Overview TC SM tests
- [x] Fix notes according to Yueh-Huan suggestions
- [x] Overview the newly introduced xApp API & E42 iApp
- [x] Prepare a guide for FlexRIC deployment

**What I have learned**
- Traffic Control test xApps
- An understanding of the newly introduced xApp API and E42 iApp architecture and communication process
:::

### Week 12:
- FlexRIC RAN DB and RAN Management ([2022/08/08~09](https://hackmd.io/JffLWjX9TLmyBjjnCFBg7w?view=))

:::success
**Goals**
- [x] Trace the architecture of RAN DB and RAN Management

**What I have learned**
- FlexRIC structure for internal Near-RT RIC representation
- RAN DB management, an understanding where connected E2 nodes information is stored
:::

### Week 13:
- [x] Resolve laptop issues and university application

### Week 14:
- FlexRIC Subscription Management ([2022/08/23](https://hackmd.io/XMpnm3HyRGWIXFwKsTK6zQ?view=))
- Summary of FlexRIC Server Library architecture and implementation ([2022/08/24](https://hackmd.io/4Txp_4TsRZ2Nj2j2lCT9Jg?view=))
- Slide ([2022/08/25](https://docs.google.com/presentation/d/1izpfnDo4bYI3ia5Kp_xg6JDJhY-hoe0yGgSPTf2uQjs/edit?usp=sharing))

:::success
**Goals**
- [x] Trace the archeticture of Subscription Management
- [x] Summarize OAI Near-RT RIC architecture and implementation
- [x] Prepare a slide of the above

**What I have learned**
- Summary of FlexRIC Architecture
:::