Journey to 5G adoption: Key network transformation areas
Adoption of 5G is one of the major focus areas of most global Telco providers currently with hopes of utilizing 5G to provide many new services to users & creating new revenue streams. In order to achieve the same Telcos have been on a network transformation journey from last 4–5years by initially focusing on virtualizing their Infrastructure & Network Elements & then on moving network to the cloud by adopting cloud technologies. However, based on where the operator is located,the regulatory norms and technology adoption status in the region and their financial health, the operators are in different phases of the transformation.
While transformation is essentially never ending, in this article we will be briefly looking into the key areas of network transformation that network operators need to focus on as part of their 5G adoption roadmap to realize maximum benefits of 5G.
Key focus areas to consider as part of Network Transformation for maximum 5G benefits
For the 5G Network to be most efficient the design should ensure that it’s “Agile to the core” and to achieve this the target should be to build 5G network on a network cloud, using “Open” architecture, leveraging disruptive technologies like AI/ML/Cloud & having automation built in.
Below are some key focus areas that should be considered as they are either essential for 5G or recommended :
1. Adopting Cloud Technologies:
5G has been designed incorporating Cloud infrastructure as its foundation & in order to see the true potential, its essential cloud technologies are adopted throughout the network. Depending on the workloads/use case & the expected amount of traffic decision can be taken on the type of cloud setup required (private/public/hybrid) and the service type to be utilized on each cloud (IaaS/PaaS/SaaS).
Adoption of cloud technologies, will also help the Telcos to better manage the data center traffic, associated CAPEX & OPEX costs & provide additional avenues for Data redundancy ( subject to regulations).
2. Containers based Microservices Architecture:
Microservices is one of the big developments of last decade which has changed the way applications are built, packaged & ultimately deployed by decomposing the monolithic application into services modules where each service is a functionality that is performed by the application. Microservices implementation has enabled service modules to be developed independently and in parallel to each other making the development cycle more agile and enabling faster turn around time for the application. Also as each service is independent, each service is deploy-able independently as per continuous deployment methodology & scaled as well independently as and when required.
With software becoming independent since introduction of virtualization & containerization in Telecom, the microservices based architecture has become the requirement for application/software which are part of Telecom architecture. Additionally, with cloud & cloud technologies serving as base for 5G(including some 4G implementations) and all latest telecom technologies, containerized versions of applications/software has become necessity to be able to utilize the benefits provided by cloud computing & to be able to utilize the portability benefit provided by containers in Telcos Hybrid Cloud Setup.
3. OSS/BSS Modernization:
Modernization of BSS (Business Support System) & OSS (Operations Support System) is not something new to 5G. However, it is a crucial from perspective of 5G benefits realization.
As per the points we have discussed above, the BSS/OSS systems should undergo digital transformation such that in the end it is essentially running on cloud, having microservices based implementation deployed as containers & leveraging automation & orchestration in its entire setup where ever possible along with Artificial Intelligence & Machine Learning capabilities in order to achieve close to perfect “Zero Touch Provisioning”. Also, to further ensure OSS/BSS is having “Open” architecture the systems should be compliant to TMForum standard specified interfaces and OpenAPIs.
From 5G perspective, The dream scenario would be for the entire use case/service order journey till activation to take place with a click of a button. Eg: If telco’s customer wants an IoT service then:
- Order would be fed manually into the CPQ software (Configure, Price, Quote).
- The CPQ would interface with the BSS systems (Product/Service Catalog, CRM(Customer Relationship Manager)) to check available catalog options, getting/updating customer data and provide pricing to customer.
- The sales agent would accept the price or make any necessary correction and submit the order.
- Once order is submitted then order would go to order system, update inventory systems and then service design should takes place where service order is decomposed into workflow tasks.
- The workflow tasks are executed by service/network provisioning and finally orchestration & activation for both IoT device as well as the IoT service on 5G Core (including 5G slice selection if setup) through domain/service orchestrator like MANO.
- Once service is active intimation is sent to Billing systems to bill usage to customer & customer notified of service readiness.
- Also service monitoring & fault management tasks take place and in case of any issues detected by assurance system automatically closed loop assurance will get triggered to the MANO system and the network elements as applicable.
In entire journey in above dream scenario user involvement is mainly towards order time & nothing else. But in a practical scenario as well user involvement can be made minimal with proper network architecture design & digital BSS/OSS system described above.
The below figure shows the BSS/OSS systems and their connectivity from end to end perspective. of BSS/OSS cycle .
4. End to End Network Service Orchestrator
As operators started transforming their networks to include virtualization and containerization, they have started adopting different MANO(Management & Orchestration) solutions to orchestrate and mange lifecycle of Network functions (Virtual or Containerized). However, the setup is are more geared towards VNFM(VNF Managers) provided by specific vendors and VIM(Virtual Infrastructure Manager) provided by the virtualizing platform/Kubernetes. Also, involvement of NFVO(NFV Orchestrator) & G-VNFM (Generic- VNFM) is in limited capacity only within the scope of select network elements or use cases. The ETSI NFV architecture showing the MANO components can be seen in the image.
To make 5G efficient, in order to automate & orchestrate majority tasks with minimal user intervention, the operators should have an End to End Network Service Orchestrator that would handle requests from BSS OSS and manage the same by orchestrating request through existing orchestrators & overall end to end managing lifecycle of the 5g network/use case. Also the end to end orchestrator could as well serve as domain/service orchestrator if required, assist with closed loop automation & manage lifecycle of individual network functions if required.
Below image showcases end to end orchestrator in an example.
Example: An operator has deployed 3 clouds — RAN, 5G Core & Edge and looking to deliver 5G service and Edge service. Their Edge service implementation involves selection of the 5G core elements from 5G core cloud and integrating with Edge Network functions present on the Edge cloud.
For this scenario orchestration & lifecycle management, the operator has following orchestrators: (i) 3 VIMs — to manage the 3 infra cloud platforms (ii) 2 VNFM — to manage RAN & 5G Core/Edge (iii) 3 NFVO — to orchestrate & setup RAN xNFs, 5G Core xNFs & 5G/Edge service (iv) 1 End to End Network Service Orchestrator — which would receive request from SOM or Service fulfillment and automate orchestration through relevant NFVO/VNFM & appropriate VIM. Also the orchestrator would coordinate with assurance for any close loop assurance aspects.
5. ORAN implementation:
In the points covered so far, we have focused more on telecom systems perspective on which 5G technology would run rather than 5G technology network elements/architecture perspective. In this point we are looking at 1 of the core elements of 5G technology i.e. Radio Access Network (RAN). RAN along with 5G core & application servers plays a major part from 5G Network realization perspective.
Open RAN (ORAN) is essentially Cloud RAN / virtualized RAN implementation with “Open” interfaces. With goal of 5G network to be “Open” in a cloud platform, Open Cloud RAN is the obvious choice of implementation to achieve the same. Operators are already slowly migrating from traditional cell sites to deploying virtualized/cloud RAN solution and Open RAN timing essentially couldn’t be better as it saves the operators from investing too much on first migrating to vRAN/cloud RAN and then to ORAN. Also in case operator has migrated to vRAN solution implementing of ORAN will not be a big challenge as it mainly would involve deploying new xNF for Radio Unit(RU),Distributed Unit(DU) & Control Unit(CU) which support “Open” interfaces from ORAN offering of vendors.
Additionally, OpenRAN architecture has introduced a component for orchestration aspects, management and automation of RAN elements called SMO (Service Management & Orchestration). SMO’s role will be vital when 5G use cases involving Network Slicing are needed and their orchestration / management is required.
The SMO can be integrated with an E2E network service orchestrator(as mentioned in point 3) to automate the overall request process from BSS/OSS.
The ORAN architecture from ORAN Alliance is shown in image below.
6. Service Based Architecture 5G Core:
The last key focus area is another core aspect of 5G Technology i.e. 5G core. 5G Core will be dealing with both data/voice user plane traffic as well as control plane traffic and working along with RAN for 5G connectivity & application servers for use cases realization.
Operators need to implement the 5G core which uses Service based architecture and defined by ETSI TS 123 501 . The 5G core involves separation of Control & User Plane functions based on services being implemented (essentially decomposing into microservices) and making it more modular . This implementation permits placing Control functions at more centralized locations while User plane functions at individual data center/cloud locations. Also, this architecture enables supporting of Network Slicing use cases to allot portion of Packet core for use in IoT or Edge or any other 5G use cases as required.
The 5G architecture is shown below:
The network functions part of 5G core are: Authentication Server Function (AUSF) ; Access and Mobility Management Function (AMF) ; Data Network (DN) e.g. operator services, Internet access or 3rd party services ; Unstructured Data Storage Function (UDSF) ; Network Exposure Function (NEF) ; Network Repository Function (NRF) ; Network Slice Specific Authentication and Authorization Function (NSSAAF) ; Network Slice Selection Function (NSSF) ; Policy Control Function (PCF) ; Session Management Function (SMF) ; Unified Data Management (UDM) ; Unified Data Repository (UDR) ; User Plane Function (UPF) ; UE radio Capability Management Function (UCMF) ; Application Function (AF) ; User Equipment (UE) ; (Radio) Access Network ((R)AN) ; 5G-Equipment Identity Register (5G-EIR) ; Network Data Analytics Function (NWDAF) ; CHarging Function (CHF).
Conclusion
While change is only constant in transformation & there are alternatives to keep the ball rolling for operators, above points if adopted position operators in best possible way for taking advantage of 5G & forward looking into realizing 6G, 7G & so on…
Disclaimer: The post above expresses my sole viewpoint and not the opinion of any organization I work with presently or in the past.
