1、INTRODUCTION 5G NETWORK: CHALLENGES AND OPPORTUNITIES5G NETWORK ARCHITECTURE DESIGNTYPICAL 5G NETWORK CAPABILITIESSTANDARDIZATION SUGGESTION CONCLUSIONS MAIN CONTRIBUTORSIMT-2020 (5G) Promotion Group was jointly established in February 2013 by three ministries of China (including MIIT, NDRC, and MOS
2、T) based on the original IMT-Advanced Promotion Group. The members include the main operators, vendors, universities, and research institutes in China. The Promotion Group is the major platform to promote 5G technology research in China and to facilitate international communication and cooperation.I
3、MT-2020 (5G) Promotion Group5G Network Architecture Design White PaperP1P2P5P10P19P21P22CONTENTS 1IMT-2020 (5G) Promotion Group5G Network Architecture Design White PaperAlong with the research on 5G getting further and more detailed, the industrials have shaped the basic consensuses on 5G scenarios.
4、 Facing to the application scenario of enhanced mobile Internet, 5G can provide access capability with higher experienced data-rate and wider bandwidth to support multimedia contents featured by higher definition and living experiences. Facing to the interconnection scenario of massive IoT devices,
5、5G can provide optimal control capability of higher connection density signaling to support the access management of IoT devices featured by massive, low cost and power consumption. Facing to the vertical business scenarios such as critical communication or industrial Internet, 5G can provide inform
6、ation interaction capability with extreme low latency and high reliability to support service cooperation featured by high performance of real-time, accuracy and security among various interconnected entities.Due to the extreme 5G requirement on experience, efficiency and performance, as well as the
7、 vision of “everything connected”, 5G network now is facing new challenges and opportunities. Based on the core principles such as network service convergence and on demand service provision, 5G introduces richer radio access network architecture, providing smarter capabilities like radio control, s
8、ervice awareness Introductionand protocol stacks. 5G reconstructs the control and forwarding function in the core network, refreshing the existing single pipeline and consolidated service model. 5G will provide highly customized network services for different user and vertical business on top of the
9、 new friendly and openness infrastructure. Above all, 5G will transform the network into an integrated information service enabling platform which has the characteristics of fully resource sharing, easily function orchestration and tightly service interworking. The international 5G standardization w
10、ork has been launched completely. Therefore, it is very necessary to refine the design of 5G network architecture and focus on main technology direction to guide the follow-up industrial development. In this white paper, we introduce a novel 5G network architecture design from the angel of logical f
11、unction and platform deployment and expand the architecture design into four-dimension diagrams, then extract the typical 5G service capabilities such as network slicing, mobile edge computing, on-demand mobile network reconstruction, user-centered RAN and network capacities exposure, and finally of
12、fer advices on the standardization work of 5G architecture and technology.2IMT-2020 (5G) Promotion Group5G Network Architecture Design White Paper1. Challenges from extreme high KPIFirstly, 5G system plans to provide 100M to 1Gbps experience data rate anytime and anywhere to satisfy the mobile inter
13、net consumers experience requirements for services such as HDTV and argument reality. Even in a high-speed mobile environment up to 500km/h, the system shall offer basic service capability and necessary service continuity.Secondly, 5G system need to support at least tens of Tbps/km2traffic volume de
14、nsity and millions/km2 connection density at the same time for the efficient access requirements of devices in both mobile Internet and IoT scenarios. The traditional network system which is marked by center-converging data forwarding 5G Network: Challenges And Opportunitiespattern and single contro
15、l mechanism may lead to traffi c overhead and signaling congestion under 5G service background which is featured by high throughput and massive connection.The last but not the least, 5G system must satisfy the end to end ms level latency requirement under the high reliability condition to support th
16、e high real time service such as automated driving and industry control. The latency and service interrupt time of todays mobile system is up to about hundreds milliseconds, which is two order of magnitude higher than 5G latency budget. The exsiting network also can not well support the reliability
17、and sercurty requirement of specifi c services.Firgure-1 5G E2E network challenges3IMT-2020 (5G) Promotion Group5G Network Architecture Design White Paper2. Opportunities by network and service convergenceConsidering the resources reservation for events that may suddenly or periodically happen, the
18、mobility management for scenarios from high-speed rail to stable wireless sensors, and the latency demand of services from real time industrial control to remote meter reading with high time tolerance, all of these 5G services scenarios have put forward higher and more differentiated demands on netw
19、ork functions. To solving such a diverse sort of service scenarios, the novel 5G network concepts like network-service convergence and on-demand service provision will bring new opportunities to all the sectors of the information industry. Based on the position advantages of “last mile” of 5G networ
20、k, the Internet applications provider can offer user experience with better discrimination. For example, mobile app can filter out most appropriate service parameters according to the location area, movement tracks and radio contexts exposed by network to increase the satisfaction of gold customers.
21、 Meanwhile, ISP can offer particular users with latency and bandwidth assurance by using of network edge caching and computing to gain an early advantage.Based on the infrastructure advantages of “Full coverage and End-to-End” of 5G network, the IoT service demand-side represented by vertical busine
22、ss can easily obtain the powerful and flexible service deployment environment. Vertical business can obtain the rich means to monitor and manage the terminals and devices in the network and control the entire service running states relying on the powerful network management system. 5G infrastructure
23、, which allows flexible function customization and resources configuration, can offer the 3rdparty service demand-side with the ability to construct a service platform of their own. In this platform, user data can be safely isolated and HW/SW resource can be dynamically scaled which may dramatically
24、 reduce the development threshold. From the angle of mobile network operators, 5G network may help them to further increase profits and reduce expenditures. In the perspective of profits increasing, 5G network break existing isolated and consolidated service provision framework, comprehensively open
25、 the network functions such as infrastructure resources, networking and control logic etc. to construct the 4IMT-2020 (5G) Promotion Group5G Network Architecture Design White Paperintegrated information service enabling platform and bring new service growth points for mobile network operators. In th
26、e perspective of expenditures reducing, on-demand function and infrastructure resources provision mechanism will facilitate enhanced energy conservation and CapEx/OpEx per unit dataflow.In particular, along with the deep convergence of mobile network and Internet, these two domains also mutually int
27、eract and infiltrate to each other positively at technical aspect. The Internet technologies such as cloud computing, virtualization and softwarization would be the important enablers of 5G architecture design.Firgure-2 5G integrated information service enabling platform5IMT-2020 (5G) Promotion Grou
28、p5G Network Architecture Design White PaperThe design of 5G network architecture includes two parts: system design and networking design. The system design mainly considers the network function and information interaction issues and aims to build a E2E unified logical architecture which has more rea
29、sonable function plane partitions. The networking design focus on the solution of hardware platform and networking deployment and attempts to fully realize the potential of the networking flexibility and security of the novel infrastructure environment based on SDN/NFV technologies.5G Network Archit
30、ecture Design1. 5G system design: logical diagram and function diagramAs shown in Figure-3, the logic diagram of 5G network consists of three function planes: access plane, control plane and forwarding plane.Access plane can accommodate more flexible radio access network topologies by exploiting mul
31、ti-BS co-ordination, multi-connection mechanism and multi-RAT interworking technology. Control plane can provide on-demand network control functions such as radio resources management, mobility management and session management based on the centralized and restructurable control function modulars. F
32、orwarding plane has the ability to forward and process the service data in a distributed manner and provide more dynamic IP anchor configuration and richer service chain capability.Firgure-3 Logical diagram of 5G network6IMT-2020 (5G) Promotion Group5G Network Architecture Design White PaperBased on
33、 the overall logic architecture, 5G network function diagram uses the modular-based design principle and build the specific logic network via the composition of the network function modular to meet different scenarios. As shown in Firgure-4, 5G three-layers network function diagram takes control fun
34、ction layer as the core, and the access and forwarding function layer as the basic resources and provides the orchestration and capabilities exposure layers functions as interface to the 3rdparty. Open interfaces are used to support the flexible inter-layers function invocations. The main functions
35、of each layer include the following:Management and Orchestration layer consists of three function modules name as user data, management and orchestration and capabilities exposure. The user data function stores the user subscribtion profile, service policies and network context information. Manageme
36、nt and orchestration function can create and management network slicing on-demand based on the NFV platform. Capabilities exposure function handles the gathering and encapsulating jobs of the network capabilities and exposes them via APIs to the 3rdparty.Network control layer includes all the contro
37、l function of 5G network, for example, centralized radio resource scheduling, integrated multi-rat control, MM, SM and security management and flow control. According to the instructions from the Management and orchestration layer, related control functions can be composed in this layer to implement
38、 on-demand scheduling of the network resources in the lower layer.Network resources layer can be divided into access side and network side. The RAN side functions are achieved by hierarchical functional entities, called central units (CUs) and distributed units (DU). While CU acts as the RAN anchor,
39、 DUs are remote access points for UEs, equipped with RF and part of baseband processing functions. Network side functions include the data forwarding, traffic optimization and content-oriented function. Based on the distributed IP anchor and flexible data forwarding paths, the user data flow can be
40、introduced to appropriate nodes to implement the efficient forwarding and rich processing functions such as DPI, content-based charging and flow compression etc.7IMT-2020 (5G) Promotion Group5G Network Architecture Design White PaperFirgure-4 Function diagram of 5G network2. 5G networking design: pl
41、atform diagram and networking diagram5G infrastructure platform will choose more and more standardized data centers with universal hardware architecture. The platform should support high performance forwarding and carrier level management. 5G infrastructure platform will take network slice as the cu
42、stomized mobile network instance.By introducing SDN/NFV technologies (shown in Figure-5), 5G platform diagram could support dynamic resource allocation and high efficient scheduling. At the WAN level, the NFV orchestrator function could achieve function deployment and resource scheduling across data
43、 centers, and SDN controller could realize the WAN level interconnection between data centers in different levels. In the MAN level and below, single data center is used to carry functions for limited geo area which includes the unified NFVI infrastructure layer to realize the hardware and software
44、decouple and the intra data center resource scheduling based on the SDN controller.The implementation of NFV/SDN technology in the access network platform is an important research point of todays industry. With the platform virtualization technology, multiple types of wireless technologies could be
45、supported simultaneously by 8IMT-2020 (5G) Promotion Group5G Network Architecture Design White PaperFirgure-5 Platform diagram of 5G networkone single platform, and the logical RAN entities and functions can be dynamically migrated in real-time, achieving higher level of resource scalability. By RAN
46、 virtualization, diverse RAN function entities can be dynamically seamless connected, in adaptation to differentiated edge RAN services requested by UE. In addition, to satisfy the special requirements of RAN virtualization, i.e. RAN accelerator for non-virtualized RAN functions and high speed infor
47、mation exchange among virtualized function entities, enhanced virtualization management and orchestration technologies should be utilized.SDN/NFV technology will further lift the 5G capability of forming large scale network. NFV technology could achieve bottom-up mapping of physical resources to vir
48、tualized resources, create the virtualized machine (VM) and load the virtualized network function (VNF). The virtualization system could realize the unified management for the virtualized basic infrastructure platform and dynamically reconfigure of the resources. SDN technology could interconnect th
49、e virtualized machines and create the signaling and data forwarding path. The intent of the network virtualization is to realize the dynamic connection between RAN and CN, configure the end-to-end service chain, and construct a flexible network.Generally, the 5G networking is consisted of four levels as shown in Figure-6:Central level: the main responsibility is for control, management and scheduling. The central level could be deployed in the national nodes and realize whole network monitoring and maintenance.9IMT-2020 (5G) Promotion Group5G Network Architecture Design White PaperFi
