This section provides an overview of the deployment topologies and considerations for 5G Core, RAN, OSS, and legacy NF use cases and architectures commonly used by Communication Service Providers (CSPs).
Telco Cloud Building Blocks
The following figure illustrates the functional building blocks of the Telco Cloud. Each building block comprises components that meet the end-to-end requirements of the Telco Cloud Platform.
Telco Cloud Infrastructure:
Hypervisor and Virtual Infrastructure (VI): Hypervisor allows multiple workloads to run on a single server. This improves asset utilization, reduces the total cost of ownership, and allows divergent workloads to run simultaneously.
VMware Telco Cloud Platform uses VMware ESXi as its hypervisor. ESXi coupled with vCenter (VI component) form vSphere. This combination provides the best-in-class Hypervisor and Hypervisor management capabilities, while continually evolving to support the growing demands of Telco.
To ensure efficiency and optimal performance of all telco workloads, the hypervisor must support the following advanced features:
Enhanced Platform Awareness: NUMA Alignment, CPU Pinning, Symmetrical Hyperthreading, SR-IOV support, and so on.
IPv6 Capabilities: Supports modern IP addressing requirements from Telco users.
Physical and Virtual Device Pass-Through (PT): Allows server hardware to be exposed to the guest OS. For example, inline or look-aside accelerators for RAN use cases
Energy Efficiency Configurations: Balances the requirements for high performance and energy efficiency.
Live Patching: Simplifies security updates while minimizing operational impacts.
Software-Defined Storage (SDS): SDS is a highly scalable, high-performance, and robust storage solution for the Telco Cloud. It provides a shared storage environment that leverages software policies to simultaneously offer multiple storages based on workload needs and allow dynamic changes to storage requirements.
VMware Telco Cloud Platform leverages the HyperConverged infrastructure (HCI) model, where the disks (such as SSDs and NVMe) that are physically installed in the server are used to provide a portion of the overall data storage.
VMware Telco Cloud Platform uses VMware vSAN as its Software-Defined Storage solution, although Telco Cloud operators can choose a different interoperable storage solution that is compatible with the Hypervisor or VI layer. For example, NVMe over Fabric, iSCSI, NFS, and FCoE.
vSAN provides the following features to maximize performance and storage operations across the Telco Cloud:
Highly Available: Enables the storage platform to grow on demand without impacting existing workloads.
High performance: Supports the most I/O intensive workloads.
Software Policy Support: Leverages software policies to simplify and manage storage requirements for different workloads.
Cost Efficient: Does not require expensive external storage arrays that might complicate architectures.
Software-Defined Networking (SDN): SDN is a software-based implementation of traditional switching, routing, security, and other networking features independent of the physical networking infrastructure. The SDN separates the control-plane and data-plane components of networking, leveraging a manager or controller to run control plane components while distributing the forwarding plane throughout the infrastructure.
VMware Telco Cloud Platform uses VMware NSX as its SDN platform. NSX integrates with vSphere components to provide all the essential software networking constructs with maximum efficiency, allowing operators to be more agile in creating the required networking topologies for complex telco network functions.
In addition, several NSX features are enhanced to meet the complex and wide-ranging telco requirements:
Enhanced Data Path (EDP) Forwarding: A hypervisor kernel based DPDK implementation that provides increased throughput for data-plane applications while supporting the traditional cloud architectural requirements.
VRF & BGP eVPN: Advanced BGP Ethernet VPN topologies, coupled with Virtualized Routing and Forwarding instances, allow for increased control plane and data-plane scalability while supporting more modern and advanced network architectures.
IPv6 Support: Ensures that telco requirements across all components within the telco cloud are compatible with IPv6.
Virtual Infrastructure Manager (VIM): In the ETSI / NFV framework, the VIM manages and controls the underlying infrastructure, which includes the Hypervisor, SDS, and SDN layers in the Telco Cloud Platform.
The VIM manages the southbound interaction with the Telco Cloud Infrastructure tier and also provides northbound interfaces for integrating external orchestration platforms.
VMware Telco Cloud Platform uses VMware Cloud Director as its VIM. VMware Cloud Director is a proven, robust VIM platform that continually evolves to meet the stringent requirements of telco. It integrates with Hypervisor, SDN, and SDS layers and complements the overall Telco Cloud Platform architecture.
The VIM supports various enhancements that are essential for telco:
Multi-Tenancy: Allows multiple tenants to onboard workloads with vastly different requirements in a controlled environment.
Advanced Resource Allocation: Allows the control-plane and data-plane network functions to co-exist and run simultaneously on the same hardware.
IPv6 Support: Provides IPv6 compliance across all SDN components within the telco cloud to meet telco user requirements.
L4-L7 Load Balancer: The Load Balancer is a secure and highly available platform for load-balancing services for some management components in the Telco Cloud Platform. It supports load balancing for the VIM platform and also the load balancing and ingress services for cloud-native workloads, by using a single platform for operational simplicity and cost-effectiveness.
VMware Telco Cloud Platform uses VMware Avi Load Balancer as its L4-L7 Load Balancer. Avi Load Balancer offers full support for all workload types with a single management plane and a scalable, distributed data-plane.
Avi Load Balancer has evolved to support many use cases and acts as a single platform for all L4-L7 use cases. The enhancements specific to Telco workloads include:
Stream Control Transmission Protocol (SCTP) Support: Supports SCTP, a common replacement for Transmission Control Protocol (TCP) within telco applications.
IPv6 support: Provides IPv6 compliance across all SDN components within the telco cloud to meet telco user requirements.
Note: NSX also provides L4 load-balancing services. However, it is limited to the Management domain and Telco Cloud appliances that require an external load balancer. Hence, NSX load balancing services can be used only for simple L4 use cases such as the VIM layer (Cloud Director) and cannot be leveraged across workload domains or in the Kubernetes domain as a Load Balancer or Ingress.
Telco Cloud CaaS:
Kubernetes: Kubernetes has become the de facto orchestration platform for containerized and microservices-based workloads. It offers declarative models for workload deployments and self-healing capabilities. It also supports dynamic scaling and distributed deployment models.
In the Telco Cloud Platform (for both Core and RAN use cases), Kubernetes requires the hypervisor layer. The Management plane, Control plane, and worker nodes of Kubernetes run as Virtual Machines on top of the hypervisor-based infrastructure. This model allows different telco workloads to run on the same physical hosts. These workloads can have different Kubernetes versions, different kernel versions (Real-Time and Non-Real Time Kernel releases), and diverse networking requirements, all serviced by the IaaS layer.
VMware Telco Cloud Platform uses VMware Tanzu Kubernetes Grid as its Kubernetes distribution. VMware Tanzu Kubernetes Grid supports a wide range of Kubernetes releases and functionalities packed in a convenient model, making it easier to build and support various Kubernetes distributions.
VMware Tanzu Kubernetes Grid is enhanced with additional features specific to the Telco Cloud Platform:
Complex networking architectures: Supports Multus, SR-IOV, and DPDK requirements for data-plane workloads.
IPv6 capabilities: Supports modern IP addressing requirements for Telco users.
Physical and Virtual Device Pass-Through (PT): Allows server hardware to be exposed to the Kubernetes layer. For example, exposing NIC PTP or GNSS timing capabilities to Network Functions.
Telco Operators: Telco Cloud Platform deploys additional operators into the Tanzu Kubernetes environment to support massive automated customization of the Kubernetes environment. Automated customization includes everything from kernel version changes to paramaters exposing Platform Awareness features and supporting declarative requirements that govern how the VM, Guest Operating System, and Kubernetes are configured.
Telco Cloud Automation (TCA): TCA manages the creation and lifecycle management of Kubernetes clusters and also the design, instantation, and lifecycle managment of both VNF and CNF workloads.
The hypervisor layer of the Telco Cloud Platform provides the best-in-class Hypervisor and Hypervisor management capabilities, while continually evolving to support the growing demands of Telco.
To simplify the operational capabilities of the Cloud-Native Telco, TCA supports the following common requirements for Telco workloads.
Multi Kubernetes Releases: Supports efficient lifecycle management of Tanzu Kubernetes Grid clusters across multiple releases, allowing operator-defined cadence for cluster and NF lifecycle.
IPv6 Capabilities: Supports modern IP addressing requirements for Telco users.
Infrastructure Policies: Supports advanced configuration of Telco Workloads in a declarative method, allowing Telco Operators to customize Kubernetes Clusters for specific workloads. This feature simplifies the management of diverse Kubernetes clusters.
Tenancy and RBAC: Allows TCA to act as a secure tenant interface to the Telco Cloud Native environment, providing secure access to Kubernetes clusters and the management platform.
Certificate Management: Provides Telco Operators a simple interface to view and in the future to manage the integrated components and their public certificates.
Workflow Hub: A serverless workflow engine that allows for easy integration into Continuous Integration, Continuous Delivery, and Continuous Testing (CI/CD/CT) toolchains and completes the automation journey for Telco users.
Telco Cloud Container Registry: The Container Registry hosts the Open Container Initiative (OCI) Images and HELM charts, which represent the cloud-native network functions and their deployment models in Kubernetes environments.
VMware Telco Cloud Platform uses Harbor as its Container Registry. Harbor is provided as part of the Telco Cloud Platform as a cloud-native application. It integrates with Telco Cloud Automation and Kubernetes clusters to simplify the Kubernetes requirements that are necessary to pull helm charts and OCI images from a secure Container Registry.
Harbor supports the following capabilities in VMware Telco Cloud Platform:
Cloud-Native deployment: Supports self-healing capabilities of Kubernetes and offers high-availability models for the container registry in future releases.
Modern Cloud-Native Registry: Supports both OCI images and storing HELM charts as OCI components.
Process Enhancements: Includes built-in processes for common activities such as Certificate replacement and storage expansion.
Telco Cloud Airgap Server: The Telco Cloud Airgap Server allows Operators to deploy and manage Kubernetes clusters with advanced configuration options, without requiring external internet access.
For Telco workloads that require advanced configuration, such as Kernel version, specific DPDK releases, or other kernel and OS parameters, these configurations are dynamically added to the environment during workflow instantiation and are stored in the Airgap Platform.
The Airgap Server integrates with the Telco Cloud Platform and Telco Cloud Automation. It secures the Telco Cloud environment by isolating it from internet access and also improves the deployment performance of Kubernetes clusters.
The Airgap Server supports the following capabilities in VMware Telco Cloud Platform:
Appliance-based deployment for simple deployment onto the Telco Cloud management domain.
Support for tiered architectures to simplify the update or patching of the Telco Cloud environment,
Process Enhancements: Supports built-in processes for common tasks such as Certificate replacement and integration to Telco cloud Automation for cascading changes across the Telco Cloud Platform.
Automation: The automation tooling comprises various components such as SDKs or interfaces that work with modern programming languages as well as additional automation tooling appliances.
For Telco workloads that require advanced automation capabilities, Aria Automation Orchestrator can be integrated into the Telco Cloud Platform. Aria Automation Orchestrator is an orchestration platform that integrates with both Telco Cloud Automation and the VIM layer (Cloud Director). It allows users and tenants to create workflows and automate common actions.
Aria Automation Orchestrator complements the functionality of Workflow Hub in Telco Cloud Automation,
The Automation Tooling supports the following capabilities in the Telco Cloud Platform:
Simple Deployment: Appliance-based deployment for simple deployment onto the Telco Cloud management domain. It integrates with the Load Balancer to provide a highly available orchestration platform.
Workflow Library: Allows Operators to leverage the built-in orchestration endpoints and also leverage any existing orchestration workflows from other network domains such as IT.
Telco Cloud Operations:
Platform Logging: Platform logging captures, retains, and archives all the logging data from all the Telco Cloud Platform components, including applications if required. Platform logging can also collect security information such as audit logs and changes to the platform.
VMware Telco Cloud Platform uses Aria Operations for Logs as its Platform logging component. Aria Operations for Logs is a highly scalable platform that logs data from all Telco Cloud resources, including physical network devices. It supports log segmentation (user access) and log forwarding to external systems such as the Security Information and Event Management (SIEM) platform.
To ensure efficiency and optimal performance of all telco workloads, the platform logging component must support the following advanced features:
Scalable platform: Supports the ability to scale as the size of the Telco Cloud grows.
IPv6 capabilities: Supports modern IP addressing requirements from Telco users.
Advanced AI and ML capabilities: Simplifies workflows and enables alerting.
Logging Coverage: Supports logging for all elements within the Telco Cloud, from Physical to Service layers.
Platform Observability: Platform observability captures metrics across the Telco Cloud platform, including infrastructure, CaaS, and application layers. It creates dashboards, reporting, and alerting to assist with operational issues.
VMware Telco Cloud Platform uses Aria Operations as its Platform Observability component. Aria Operations is a highly scalable platform that captures all observability and metric data across the entire Telco Cloud platform, including physical devices.
To ensure efficiency and optimal performance of all telco workloads, the observability component must support the following advanced features:
Scalable Platform: Supports the ability to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 Capabilities: Supports modern IP addressing requirements from Telco users.
Advanced AI and ML capabilities: Simplifies workflows and enables proactive alerting.
Observability Coverage: Supports all elements within the Telco Cloud, from Physical to Service layers.
Custom Dashboard: Provides flexibility to create dashboards based on user requirements.
Network Inspection Network Inspection captures network-specific metrics, introduces support for physical network and firewalling platforms, and traces network flows end-to-end.
VMware Telco Cloud Platform uses Aria Operations for Networks as its Network Inspection component. Aria Operations for Networks is a highly scalable platform that captures all networking data across the entire Telco Cloud platform, including the infrastructure layer, CaaS layer, and physical layer from a networking perspective. It also supports physical devices (Firewalls, Switches, Routers) and the Telco Cloud components.
To ensure efficiency and optimal performance of all telco workloads, the Network Inspection component must support the following advanced features:
Scalable Platform: Supports the ability to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 Capabilities: Supports modern IP addressing requirements from Telco users.
Advanced AI and ML Capabilities: Simplifies workflows and enables proactive alerting.
Network Inspection Coverage: Supports all elements within the Telco Cloud, from Physical to Service layers.
Custom Dashboard: Provides flexibility to create dashboards based on user requirements.
End-to-End Packet Tracing: Supports end-to-end (e2e) packet tracing across SDN and physical networking.
Supports IPFIX ingestion and microsegmentation planning.
Service Assurance: Service Assurance captures application-specific metrics and logs to perform service-level monitoring and closed-loop remediation for 5G Core and RAN deployments.
The Service Assurance layer is on top of platform observability. It provides insights and dashboard around network services, covering multiple layers from the Optical layer to Physical networking and IP/MPLS layers to provide Assurance across multiple domains.
VMware Telco Cloud Platform uses VMware Telco Cloud Service Assurance as its Service Assurance component. VMware Telco Cloud Service Assurance is a highly scalable platform that captures all networking data across the entire Telco Cloud platform. It can also support physical devices (Firewalls, Switches, Routers) and the Telco Cloud components.
To ensure efficiency and optimal performance of all telco workloads, Telco Cloud Service Assurance supports the following advanced features:
Scalable Platform: Supports the ability to scale as the size of the Telco Cloud grows, leveraging distributed architectures.
IPv6 Capabilities: Supports modern IP addressing requirements from Telco users.
Advanced AI and ML Capabilities: Simplifies workflows and enables proactive alerting.
Service Assurance Coverage: Supports all elements within the Telco Cloud, across all domains.
Custom Dashboard: Provides flexibility to create dashboards based on user requirements.
Bare Metal Automation: Bare Metal Automation allows bootstrapping (at large scale) and automates the deployment and configuration of the server hosts. It supports end-to-end automation, from deploying the Guest Operating System platform to configuring BIOS and Firmware configuration, to streamline the process.
Telco Cloud Use Cases
The Telco Cloud platform is built from a suite of components. The main offerings for the Telco Cloud are as follows:
Telco Cloud Platform Essentials
Telco Cloud Platform Advanced
Telco Cloud Platform RAN Essentials
Telco Cloud Platform - Centralized RIC (cRIC) with Service Management and Orchestration (SMO)
Each offering supports a range of use cases. This guide helps you understand the mapping between the Telco Cloud offerings and the operator use cases.
The offering and mapping are not strictly enforced. However, based on the different components between the Essentials and Advanced editions of Telco Cloud Platform, you can quickly get insights into benefits and use cases for the Advanced platform.
The following diagram illustrates the Telco Cloud Platform deployment models and their components.
Telco Cloud Platform Advanced includes the following additional capabilities over Essentials:
NSX Networking
Enhanced Data Plane Use Cases
T1 / T0 Routing
eVPN Architecture
VNF Integration with VMware Cloud Director™ and NSX
vSAN licensing (1 Tib per core in Advanced vs 100 Gib per core in Essentials based starting on vSphere 8.0U2)
VMware Telco Cloud Service Assurance™
Additional Telco Cloud Automation functionalities
CNF Onboarding, Design, and Lifecycle Management
Workflow Hub
Network Slicing
VMware Aria Operations™ for Networks
The workload capabilities available through Telco Cloud Platform Essentials are as follows:
TKG (CaaS) Cluster Deployment and CaaS Lifecycle Management (Including DIP Profiles)
VNF Onboarding and instantiation through TCA or VMware vCenter Server®
VNF Onboarding and Instantiation through VMware Cloud Director
Telco Cloud Platform Essentials does not include advanced networking configuration options available with NSX and as such supports only vSphere networking configurations. Additionally, Telco Cloud Platform Essentials supports CaaS cluster creation and lifecycle management, but does not support onboarding and instantiation of CNFs. VMware expects that all CNF LCM events are handled outside of TCA by third-party components.
The foundational elements of Telco Cloud Automation and vSphere, such as RBAC, Multi-Tenancy, and Kubernetes security configurations, remain the same in both Essentials and Advanced.
The following table outlines Telco Workload use cases and maps them to the Telco Cloud Platform Essentials and Advanced offerings.
NFs and Use Cases |
Workload Type |
Telco Cloud Platform Essentials |
Telco Cloud Platform Advanced |
Notes |
|---|---|---|---|---|
OSS / BSS without advanced networking |
VNF |
Yes |
Yes |
|
OSS / BSS with advanced networking |
VNF |
No |
Yes |
|
Cloud-Native OSS / BSS |
CNF |
No |
Yes |
CNF Onboarding and LCM are not available as part of Telco Cloud Platform Essentials |
VAS Services |
VNF |
Yes |
Yes |
|
Fixed Wireline Use Cases - Control Plane |
VNF |
Yes |
Yes |
Supported only with simple network architectures on Telco Cloud Platform Essentials |
Fixed Wireline Use Cases - Data Plane (CGNAT, BNG, vMCTS, and so on) |
VNF |
Yes |
Yes |
Low-Medium throughput and Scale use cases |
Fixed Wireline use cases - Data Plane (CGNAT, BNG, and so on) |
VNF |
No |
Yes |
Medium-High throughput and Scale use cases leveraging EDP |
5G SA / DM Core |
CNF |
No |
Yes |
|
5G Core supplemental applications |
CNF |
No |
Yes |
|
4G Legacy user-plane workloads |
VNF |
No |
Yes |
|
4G Legacy control-plane workloads |
VNF |
Yes |
Yes |
Telco Cloud Platform Essentials as an architecture supports predominantly VNF workloads without complex networking and Caas Management. CNF onboarding and instantiation are not available as part of Essentials.
The following diagram illustrates the workload supported in Telco Cloud Platform Advanced. Telco Cloud Platform provides a deeper integration between TCA and Cloud Director, and additional functionalities on the CaaS and CNF Management segment.
Telco Cloud Platform additionally encompasses RAN deployment models. Similar to Telco Cloud Platform Essentials and Advanced, Telco Cloud Platform RAN supports two main offerings in the RAN scenario.
The following diagram illustrates the Telco Cloud Platform RAN deployment models.
Similar to Telco Cloud Platform Essentials, Telco Cloud Platform Essentials for RAN focuses on Caas Cluster deployment and LCM. The Telco Cloud Platform Essentials for RAN platform does not include Telco Cloud Service Assurance and the instantiation and LCM of CNFs.
vSphere, TKG-M, and Aria Suite components are not part of the Centralized RIC with SMO, but they constitute the IaaS, CaaS, and O-Cloud layers of Telco Cloud Platform Essentials for RAN.
The following table outlines various RAN workload use cases and maps them to Telco Cloud Platform Essentials for RAN and cRIC+SMO offerings. The placement of the DU and CU in Distributed RAN (D-RAN) and Centralized RAN (C-RAN) does not impact this mapping.
NFs and Use Cases |
Workload Type |
Telco Cloud Platform Essentials RAN |
cRIC + SMO |
Notes |
|---|---|---|---|---|
Caas Management Only |
N/A |
Yes |
Yes |
Cluster Creation (inc Infra Profiles) |
DU Workloads |
CNF |
No |
Yes |
CNF Instantiation and LCM |
CU Workloads |
CNF |
No |
Yes |
CNF Instantiation and LCM |
Legacy VNFs illustrated in this diagram are not using NSX. If the legacy VNFs require NSX for advanced networking, or if the deployment architecture leverages NSX, then Telco Cloud Platform also require TCA Advanced configuration.
This diagram does not show a converged management domain that hosts components for managing non-Telco workloads.
Multi-Tier and Distributed Architecture
VMware Telco Cloud is a common platform from Core to RAN. This common platform can adapt and scale automatically depending on the workload deployed through VMware Telco Cloud Automation™.
To deploy all workload types such as VNFs and CNFs from 4G and 5G Core to RAN (including 4G Control functions, 4G EPC functions, 5G Core functions, and RAN DU/CU functions), the same infrastructure components, automation platforms, operational tooling, and CaaS infrastructure is leveraged end-to-end.
The 5G network must be dynamic and programmable to achieve business objectives. Network operators must be able to provision virtual network slices on-demand with QoS. This helps meet SLAs, provision functions to increase capacity using industry-standard APIs, and re-route traffic during congestion proactively and securely.
To handle the massive data traffic, 5G is designed to separate the user plane from the control plane and to distribute user plane functions as close to the end-user device as possible. As the user traffic increases, operators can add more user plane services without changing the control plane capacity. This distributed architecture can be realized by building the data center and network infrastructure based on hierarchical layers. The following diagram illustrates a hierarchical 5G design.
Applications such as RAN cell sites, sensors, and smart devices can reside on the network edge.
Far Edge: The network far edge is the aggregation point for the geographically distributed radio sites hosting RAN and IP routing aggregators. It might also host mobile edge computing software to support private 5G use cases for factory automation, remote presence, and so on. Access mobility and user plane termination functions of the 5G core can also reside on the far edge. The type and number of applications that can be hosted on the far-edge sites are limited by available power and space.
Near Edge: The near edge is the aggregation point for far edge sites. It hosts many of the services as the far edge. It also serves as a peering point to access the Internet or other infrastructure-related cloud services. In a distributed 5G Core, the UPF can be deployed at the near edge for distributed break-out points for efficient internet and off-ramp connectivity.
The central or core sites host infrastructure components such as the VMware Telco cloud management components, Kubernetes Management clusters, CICD toolchains, Operational Support Systems (OSS), Observability platforms, Kubernetes image repository, and so on.
Depending on the 5G deployment, control plane functions of the 5G core, subscriber database, and so on can reside in the core or regional data center.
RAN Architectures
The RAN network must adhere to the multi-tier and distributed architecture of the 5G Core and the specifications of the RAN environment.
The model of the Telco Cloud architecture allows CSPs to scale 5G deployments based on application requirements and user load. Modern Telco architecture consists of four levels: 5G subscriber databases, data repositories, resource orchestration, and service assurance are typically hosted in the Central, or core data centers. The central and regional data centers also serve as peering points for lawful intercept points. For redundancy, a pair of central data centers are deployed in geographically diverse sites.
In this diagram, the regional or domain data centers host the 5G core user plane function, voice services functions, and non-call processing infrastructure such as IPAM, DNS, and NTP servers. Inbound and outbound roaming traffic can also be routed from the regional data center to the edge. With the inclusion of RAN and CRAN / DRAN, the distribution of user plane functions becomes more visible.
The Telco Cloud Platform is a compute workload domain that can span from the Core and Regional / Domain Data Centers to individual cell sites.
DRAN architecture: The Cell site uses the Distributed RAN (DRAN) architecture. This architecture uses single hosts, distributed across thousands of remote cell sites. However, more complex architectures for cell sites (with redundancy) can be used.
CRAN architecture: Near-edge sites can implement a Centralized RAN (CRAN) architecture. This architecture uses a cluster of hosts for high availability, resiliency, and scale. In the CRAN model, RAN functions are deployed outside of the cell sites.
For more information about these two architectural models, see Telco Cloud - RAN Domains.
To support new applications and devices that require ultra-low latency, localized processing, and high-throughput networks, CSPs can push the 5G user plane closer to the application edge. At the same time, RAN dis-aggregation enables efficient hardware utilization and pooling gain and increases deployment flexibility while reducing the Capital Expenditure (CAPEX) and Operational Expenditure (OPEX) of Radio Access.
The core sites (Central, Regional, and Edge sites) are part of the 5G Core architecture, while the far edge or cell sites are also commonly part of the RAN architecture for CRAN and DRAN.
5G Service-Based Architecture
5G comes with the specification of a Service-Based Architecture (SBA). The basic principles of SBA are independent of vendors, products, and technologies. A service is a discrete unit of functionality that can be accessed remotely, acted upon, and updated independently. SBAs improve the modularity of products. The network functions creating the 5G service can be categorized into communicating services. With this approach, users can deploy services from different vendors into a single product.
The following diagram illustrates various 5G Core Control Plane functions. The UPF and RAN components are User Plane Functions responsible for radio control, packet routing, Deep Packet Inspection (DPI), and other router-based functions.
Containers are used as a portable and lightweight virtualization solution for 5G Service-Based Architecture (SBA). Kubernetes is one of the components to consider when delivering Carrier-Grade Container as a Service (CaaS). 5G Core network functions are deployed in a cloud-native form although VM-based components can also exist.
A Carrier-Grade CaaS platform requires a complex ecosystem of solutions and functions to form a pre-set business and operating model. The cloud infrastructure modernization changes not only the business model in service agility and metered revenue models but also challenges the silo operating model.
5G Core and RAN Connectivity Considerations
The following core and edge connectivity considerations are required to support different deployment models of 5G RAN:
Core and Edge connectivity: Core and Edge connectivity have a significant impact on the 5G core deployment and it provides application-specific SLAs. The radio spectrum type, connectivity, and available bandwidth also have an impact on the placement of CNFs.
WAN connectivity and Bandwidth: In the centralized deployment model, the WAN connectivity must be reliable between the sites. All 5G control traffic travels from the edge to the core, so any unexpected WAN outage prevents 5G user sessions from being established.
The fronthaul traffic forwarding from the Remote Radio Unit (RRU) to the DU can be significant in a C-RAN environment, so appropriate bandwidth and infrastructure sizing are required. The WAN sizing and redundant connectivity requirements must be based on the maximum expected throughput, as required Quality of Service (QoS) can be deployed to protect high-priority traffic between the RAN and Far Edge / Core sites.
Components deployment in Cell Site: Due to the physical constraints of remote Cell Site locations, deploy only the required functions at the Cell Site and the remaining components centrally. For example, observability and logging functions are often deployed centrally to provide universal visibility and control. Non-latency-sensitive user metrics are often forwarded centrally for processing.
Network Routing and Local Break-out: Each cell site or far-edge site routes the user plane and Internet traffic through the local Internet gateways, while the device communication involving management and non-real-time sensitive applications leverages the core.
