● Microservice architecture: The essence of the SBA is based on the three principles of “self-contained, reusable, and independent management”. The network function, which is designed with the concept of “high cohesion, low coupling”, is divided into a series of small services. Each service focuses on a single business function, running in an independent process. With clear boundaries between services, it uses a lightweight communication mechanism to communicate and cooperate with each other to achieve a complete application. Based on this, operators can flexibly customize the networking according to business needs.
● Self-service: Based on the Microservice architecture, from the aspects such as blueprint design, resource scheduling and orchestration, lifecycle management, application state monitoring, control strategy update, a high degree of automation is achieved and effective linkage between the various links is made to achieve a closed-loop feedback mechanism, which can achieve one-click deployment, full autonomy, and efficient management of services.
● Lightweight virtualization: Compared to virtual machines, container technology, which has the advantages such as rapid scaling-in/out, lightweight, and high performance, is rapidly and widely used in the IT industry. The cloud native application and the underlying virtualization technology are decoupled, and can be deployed in the container technology to achieve resource utilization improvement, fast service delivery, and service agile maintenance. The ZTE 5G Common Core Solution supports both virtual machine-based and container-based deployments.
● Stateless: The 5G Common Core Solution adopts the stateless layered design. User access and session information is stored in the data sharing layer. Each Microservice instance in different locations can obtain the latest state of the user through the data sharing layer. Stateless application designs enable separation of applications from data, enabling rapid network resiliency and failure recovery.
Better User Experience
Help operators achieve early-stage deployment of 5G. The EPC core network supports Option 3/3a/3x based on LTE and NR dual-connectivity, providing support for commercial deployment of 5G enhanced mobile broadband (eMBB) services.
The ZTE EPC-NSA function helps operators deploy some 5G scenarios and functions based on EPC in the early stage of 5G deployment when the relevant industry chain is not mature; to meet the needs of some operators to deploy 5G urgently.
Registration and Connection Management
One of the key functions of the 5GC R15 is to help the operator commercialize a full 5G architecture network and achieve better access and connection management disaster recovery solutions than 4G.
The registration management function controls and authorizes users to access the 5G network, maintains user registration information and registration status, enforces mobility restrictions and tracks user location.
The connection management function includes maintaining the N2 session and the UE connection status, and making management of user reachability.
One of the key functions of the 5GC R15 is to help the operator commercialize a full 5G architecture network and achieve more flexible U-plane management than 4G. This feature includes:
i) Establishing PDU session information of the UE and controlling the establishment of the U-plane data channel, maintaining the user PDU session context;
Ii) Making management of session continuity at handover, including session continuity modes of SSC 1, SSC 2 and SSC 3;
Iii) Supporting single PDU session multi-user plane anchor, including UL Classifier and IPv6 Multi-Homing.
Improve operator software deployment and maintenance efficiency, and develop an open development ecosystem. ZTE believes that the application of core network based on Cloud Native has the following four characteristics:
1) Microservice architecture: The application, which adopts the idea of “high cohesion, low coupling” to design, is divide into a series of small services. Each service focuses on a single business function and runs in an independent process. The boundaries between services are clear. It uses lightweight communication mechanisms to communicate and cooperate with each other to achieve complete applications to meet the needs of services and users.
2) Self-service: Based on the micro-service architecture, it realizes high automation from multiple cycles such as blueprint design, resource scheduling and lifecycle management, application state monitoring, and control policy update, and the effective connection between each link realizes the closed-loop feedback mechanism, which can be used to realize the one-click deployment, full autonomy and efficient management of services.
3) Lightweight virtualization: The cloud native application is decoupled from the underlying virtualization technology, and they can be deployed in the container technology to achieve resource utilization improvement, fast service delivery, and agile maintenance.
4) Stateless: The user's access and session information is stored in the data sharing layer. Each Microservice instance in different locations can obtain the latest state of the user through the data sharing layer. Stateless application design enables separation of application from data, enabling rapid network resiliency, failure recovery, and more.
Control Plane Policy Implementation
One of the key functions of the 5GC is to help the operator commercialize full 5G architecture and deploy flexible 5G data intelligent pipelines.
The control plane policies contain AMF-related access and mobility policies, AMF-delivered UE routing policies, and SMF-related session management policies.
Convergence and Multi-access
Help the operator reduce operating costs, improve user experience and save system resources.
In addition to the integration of standard recommended control surfaces of UDM&HSS, PCF&PCRF and SMF&PGW-C, and the user-side UPF&PGW-U network function, the ZTE Common Core Solution also includes a wider range and deeper integration technology.
1) In terms of breadth: The ZTE Common Core Solution also includes the convergence of control planes of SGW-C&PGW-C&SMF in 4G/5G, convergence of AMF&MME, and convergence of user planes of SGW-U&PGW-U&UPF. Further, the ZTE Common Core Solution also integrates the functions of 2/3G network elements (HLR, SGSN, GGSN).
2) In terms of depth: The ZTE Common Core Solution is not the simple stacking of network elements. Based on the 5G core network architecture technology, NFV/SDN and cloud native design concepts, ZTE splits and reconstructs the 2G/3G/4G core network elements based on Microservices, and integrates the session context to achieve the deep integration of the 2G/3G/4G/5G Common Core on the same cloudified core network platform. This makes the 2G/3G/4G core network also have advanced features such as Microservice, stateless, control plane/user plane separation, service orchestration, 2G/3G/4G/5G mobility, and super 2G/3G/4G/.5G business integration capabilities.
Network Slicing Selection
One of the key functions of the 5GC is to help the operator commercialize a full 5G architecture and deploy a slicing network.
The network slice selection associates the UE (and its traffic) with network slicing and directs it to the resources/functions associated with network slicing. The AMF interacts with the NSSF to complete the slice instance selection, and performs AMF redistribution/migration on demand according to the slice instance selection result.
Network Slicing Isolation
One of the key functions of the 5GC R15 is to help the operator commercialize a full 5G architecture and deploy a slicing network.
This feature implements logic/isolation between network slice instances of core network, containing the following scenarios:
Group A: CN is isolated by instance
Group B: Several network slices share part of the control plane function, and the remaining control planes are separated from the user plane slice instances.
Group C: The slice instances share the control plane, and the user plane is isolated by the slice instance
Help the operator provide mature voice solutions in NR independent deployment scenarios. EPS-Fallback is one of the main options for NR's standalone deployment of the voice solution at the early stage. The UE can be registered with the IMS in the 5GS. When the UE initiates a media call, the NG-RAN triggers the fallback to the EPS network when the voice stream is established, and the 5G core network cooperates to complete the 5GC->EPC interoperation handover procedure. EPS Fallback can be used to provide voice services for users when the user triggers a voice call, and can avoid switching in the call state when the NR coverage is insufficient.
The Voice over New Radio (VoNR) helps the operators realize the 5G wireless voice solution based on the 5G network. It provides IP-based HD voice services in 5G wireless coverage areas. As an IP data transmission technology, all services are carried on the 5G wireless network to achieve unified data and voice services in the same network. The 5G network provides high-rate data services as well asand high-quality audio/video calls. The VoNR technology is used to implement audio/video calls.
This feature helps operators implement IoT services and provide industry users with diversified services.
The ZTE 5GC Common Core integrated core network supports narrowband IoT technology (NB-IoT) and enhanced IoT communication technology (eMTC). The former is used for communication between IoT devices with low power consumption, high latency, and deep coverage, and the latter is used for communication between highly reliable and low-latency objects.
5GC QoS Architecture
One of the key functions of the 5GC is to help the operator commercialize the full 5G architecture and achieve 5G full service QoS requirements.
The new QoS flow-based QoS architecture of 5GS provides more flexible and refined QoS control capabilities: The wireless resources in the QoS architecture are loosely coupled to the EPS. Wireless has a more autonomous flexibility in resource scheduling, and QoS flow capacity and radio resource capacity are no longer limited by 1:1.
The enhanced 5G QoS identifier (5QI) provides QoS control capabilities of 5G new URLLC and full service scenarios.
Reflective QoS and notification control further simplify 5G QoS management operations while ensuring QoS control capabilities.
Help to seamlessly switch session continuity and enhance user experience.
The ZTE 5G Common Core Solution supports 4G/5G interworking between 5GS-EPSs. Specifically, it includes mode of single registration with N26, mode of single registration without N26, and dual-registration mode.
The N26 interface is used in the 4G/5G interworking scenario (5GS-EPC/E-UTRAN) to transfer the mobility management and session management context of the UE between the MME and the AMF. The N26 is a subset of the existing S10 interface functions. It is easy to implement the 5GC and the existing network EPC. With the N26 interface, business continuity can be ensured, seamless switching can be achieved, and voice services have no impact.