GRUPPO TIM Technology - Innovation

SON/RAN Orchestration RAN Dynamic Reconfiguration using Controller Interfaces

T.I.MF.WSA The Groups for Network transformation towards 5G • Orchestration involves several domains and several standardization groups

• TIM Wireless Innovation Group is involved in: • RAN Management and SON • RAN Orchestration • RAN Function (eNB, gNB) analysis and testing

SON/ RAN Orchestration TIM 2 Reference Architecture 1/2 • The goal of this activity is the analysis of how RAN performance can be monitored and handled. This presentation describes the role of the RAN controller in the management of multiple RAN nodes. • The SON/RAN Orchestration is a layer containing operator policies to handle RAN. This layer can receive information/commands from E2E Orchestration or Service orchestration. • The SON/RAN Orchestration can modify RAN configuration exploiting interface exposed by RAN controller

SON/ RAN Orchestration TIM 3 Reference Architecture 2/2

• APIs between RAN Node and RAN Controller provide Measurement and Quality information on RAN status and can modify Scheduler Policies or Network Parameters in order to handle dynamically RAN needs (eg: increment of users, node out-of-service, coverage extension) • OpenAirInterface is used as network node in order to integrate some agent for node reconfiguration • APIs between RAN Controller and SON/RAN Orchestrator allow real time adaptation of the network to the service requirement: • Enabling specific band limitation on user subscription base • Enabling monitoring of neighbors cells power when user is in bad radio condition (cell-edge) • Other services can be enabled …

SON/ RAN Orchestratine TIM 4 Open-RAN Forum • A similar architecture is proposed by O-RAN Forum: https://www.o-ran.org/ • The X-RAN Forum (now O-RAN) was formed in 2016 with the goal of standardizing an open alternative to the traditional hardware-based RAN. The group focuses on three areas: decoupling the RAN control plane from the user plane, building a modular eNodeB software stack that uses COTS hardware, publishing open north- and south-bound interfaces.

SON/ RAN Orchestration TIM 5 Lab Configuration • OpenAirInterface (OAI) is used to implement a software eNodeB; this first implementation does not provide eNodeB in VM • Controller and Orchestrator are provided as software running in a VM • Lab configuration

• 4 OAI eNodeB • 2 EPC usable with OAI – OAICN – Amarisoft • 1 EPC at the moment not usable with OAI (NextEPC) • Controller runs in 1 VM in order to receive and send data to the OAI eNodeB • Orchestrator/SON Layer exploits the Controller API to realize specific Use Cases

SON/ RAN Orchestration TIM 6 OpenAirInterface eNodeB Modifications • During openair2/Layer2 configuration two thread are launched: • C-Agent “reading thread” collects information from openair2 in a struct (TMSI is recovered by openair3): – QCI – CQI – RSRP/RSRQ – TMSI/RNTI • C-Agent “writing thread” can change parameter inside openair2: – Scheduler RBG assignment for a specific UE – Transmission of a new RRC Connection Re-Configuration • The information collected by reading thread is forwarded to the OAI agent and the information provided by the RAN Controller to the OAI agent is forwarded to the writing thread • Python agent is an easy-way to serialize information SON/ RAN Orchestration using json or ASN1 TIM 7 Interface Definition • The information on the status of each OAI nodes • The information transmitted from the RAN is periodically transmitted (e.g. :every 5s) Controller to the eNodeB is transmitted only { when the eNodeB needs to be reconfigured. Because of multiple eNodeB the message head "3": { contains the node id of the eNodeB "user_1": { "cqi": 15, {

"qci": 8, This message is relate to a specific UE "crnti": 30633, "crnti" : 1356,

grow with the the with grow "starting_rbg" : 0, "tmsi": 2, n message_mac =1 means that UE "rlcDlThr" : 0.0 "num_of_rbg" : 12, allocation is limited: starting from "rlcDlbuffer" : 0.0 "message_mac" : 0, the Resource Block Group (RGB) "rsrp": 62, "message_rrc" : 0, Measurement Value Index of serving cell : " starting_rbg" for a number of "rsrq": 31, "reset_idx" : -1 "num_of_rbg" "neighbors": { } "2": { Id of neighbor cell "rsrp": 53 It is used to reset the This field is used to transmit a specific number of attached UEs attached of number "rsrq": 14 information of a RRC Message: Vector with Measurement Value Index of } specific user (index 0: no RRC modification neighbor cells "1": { from 0 to 15), when 1: configure a Measurement Report 2: stop a Measurement Report ‘’user_n’’ information whereinformation ‘’user_n’’ "rsrp": 54 <0 this information "rsrq": 6 is un-used 3: Send a RRC Disconnect } } } } } SON/ RAN Orchestration TIM 8 Controller-Node Architecture

SON/ RAN Orchestration TIM 9 Controller-Node Architecture: Localization APP • Using this architecture some APPLICATIONS have been already implemented: • A Monitoring Application is realized in form of Web App capable of showing in real-time the network status. This application allows to monitor network analyze the controller activity • A Localization Application using RSRP/RSRQ information provided by the Nodes to provide the position of the UE in the lab. This application is important in order to understand when the UE is in edge condition.

• B1, A2 and position are edge-regions

• A1, B2, and A3 position are good radio regions

SON/ RAN Orchestrationr TIM 10 Controller-Node Architecture: Localization APP

SON/ RAN Orchestration TIM 11 Video

Example of Measurement Report Configuration and Localization App

https://drive.google.com/open?id=1NP4UvawQUi-T6JcuIYC1UUsi1-d8et77

12 Next Activities in TIM Lab Several use cases can be supported by an Orchestrator exploiting RAN Controller Interface • Network Quality Monitoring configured by RAN Orchestrator: • RAN Orchestrator will configure an UE to report the RSRP/RSRQ of neighbor cell for a defined period, on the basis of specific Policies (e.g. User in bad Radio Condition, or when inside a specific Area) • Slicing definition: • RAN Orchestrator can describe a slice configuration for 2 or more UEs on the basis of QCI reported by EPC. A slice can be configured with UE-Specific limitation in frequency or in time. • Inter-Node Interference Coordination: • RIC can coordinate Data transition toward 2 UEs in cell-edge condition(exploiting Localization information) in order to improve DL Channel Quality

SON/ RAN Orchestration TIM 13 Thanks

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