INTRODUCTION
5G NETWORK: CHALLENGES AND OPPORTUNITIES
5G NETWORK ARCHITECTURE DESIGN
TYPICAL 5G NETWORK CAPABILITIES
STANDARDIZATION SUGGESTION
CONCLUSIONS
MAIN CONTRIBUTORS
IMT-2020 (5G) Promotion Group was jointly established in February 2013 by three ministries of China (including MIIT, NDRC, and
MOST) 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.
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CONTENTS
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Along with the research on 5G getting further
and more detailed, the industrials have shaped
the basic consensuses on 5G scenarios. 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,
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 information
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 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, service awareness
Introduction
and 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 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 work 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 function 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 offer advices
on the standardization work of 5G architecture and
technology.
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1. Challenges from extreme high KPI
Firstly, 5G system plans to provide 100M to 1Gbps
experience data rate anytime and anywhere to satisfy
the mobile internet consumer’s 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/km2 traffic volume density 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 Opportunities
pattern and single control 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 the high real time service
such as automated driving and industry control. The
latency and service interrupt time of today’s 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 and sercurty requirement of specifi c services.
Firgure-1 5G E2E network challenges
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2. Opportunities by network and
service convergence
Considering the resources reservation for events that
may suddenly or periodically happen, the 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 network 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 network, 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. 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 business
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,
which allows flexible function customization and
resources configuration, can offer the 3rd party 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 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 the network
funct ions such as infras t ructure resources ,
networking and control logic etc. to construct the
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integrated information service enabling platform
and bring new service growth points for mobile
network operators. In the 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 interact 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 platform
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The 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 reasonable 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 Architecture Design
1. 5G system design: logical diagram and
function diagram
As 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 multi-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.
Forwarding 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 network
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Based on 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 function layer as the core, and the access and
forwarding function layer as the basic resources and
provides the orchestration and capabilities exposure
layer’s functions as interface to the 3rd party. Open
interfaces are used to support the flexible inter-layers’
function invocations. The main functions 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.
Management 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 3rd party.
Network control layer includes all the control
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
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, 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 introduced to
appropriate nodes to implement the efficient
forwarding and rich processing functions such as
DPI, content-based charging and flow compression
etc.
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Firgure-4 Function diagram of 5G network
2. 5G networking design: platform diagram
and networking diagram
5G 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 customized 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 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 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 today’s industry. With the platform
virtualization technology, multiple types of wireless
technologies could be supported simultaneously by
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Firgure-5 Platform diagram of 5G network
one single platform, and the logical RAN entities
and functions can be dynamically migrated in real-
time, achieving higher level of resource scalability.
By RAN 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, . RAN
accelerator for non-virtualized RAN functions
and high speed information 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 virtualized 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 the 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.
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Firgure-6 Networking diagram of 5G network
Convergence level aims to carry the control plane
functionalities, such as the mobility management,
session management, user data storage and policy
which can be deployed at provincial network.
Regional level: the main functions are for data
forwarding, and can be deployed at the city level.
MEC function, service chain function and part
of the control plane network function can also be
deployed in this level.
Access level: mainly involves deployment of CU and
DU. CU is deployed in access or aggregation domain
of backhaul. And DU, as the access point, is deployed
close to user terminal. The enhanced low latency
transport network between CUs and DUs enables high
performance collaboration among multiple unit nodes.
Either separated CU and DU or integrated CU and DU
in a node can be flexibly supported.
In 5G networking, considering the modular
design and high efficient NFV/SDN platform,
the networking levels above would not need to
be strictly bounded with the geographic location,
but, according to operator’s networking plan such
as service requirement, traffic optimization, user
experience and transport cost, 5G networking can
achieve integration of the functions across different
levels, which may help realize the flexible functions
deployment across data center and geographic
hierarchy.
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Compared with 4G era, 5G services have specific
capabilities such as better fi t to user needs, enhanced
customization, deeper integration with services
and more friendly network function provision. The
typical 5G service can be summarized as: network
slicing, mobile edge computing, on-demand mobile
network, user-centered RAN and network capacities
exposure.
Network slicing
N e t w o r k s l i c e i s c o n s i d e r e d a s t h e k e y
characteristics of NFV application in 5G ear.
One network sl ice will build an end-to-end
logical network to provide one or more network
services flexibly according to the instructions
of slice demand-side. As shown in Figure-7,
network slicing architecture mainly includes
two parts named as slice management and slice
selection.
Slice management function integrates business
operation, virtualized resources platform and
network management system together for slice
demand-side (for example, vertical industry
customers, virtual operators and, enterprise
customers, etc.) to securely provide isolated and
highly self-controlled dedicated logical network.
Slice management function can be split into three
phases:
Business phase: in this phase, slice demand-
Typical 5G Network Capabilities
side uses the slice template and orchestration
tools provided by slice management system to
set the parameter of the slice they are commited
to, for example, networking topology, function
components, interaction protocol, performance
index and hardware specifications, etc.
Instantiation phase: instantiation of a network
slice is carried out using interface between slice
manager system and NFV MANO. Slice manager
also enforces configurat ion of the specif ic
functions and connectivity test using interface
between slice manager and network slices in order
to migrate the network slice into execution state.
Execution phase: the slice owners start real-
time operation and dynamic maintenance of their
network slices. The main function in this pahse
includes: resource scaling in/out, slice functions
addit ion/removal and alarm processing and
Firgure-7 Network slicing architecture
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contains the complete control plane and user
plane functions.
Shared architecture. Multiple slices can share
certain of network functions. Generally,
consider ing the implement complexi ty
and power consumption of UE, the user
granularity control plane functions, such
as mobility, could be the preferred shared
function. Although in general, the service
granularity control and forwarding functions
should be the independent function to achieve
specific services.
correlation (for analytics) etc.
Slice selection implement the access mapping
between user terminals and network slices. Slice
selection will offer user terminals with appropriate
access policies based on various factors such as
subscription and terminal function and so on. A
user terminal can access to one or more slices at
the same time, which may derive two slice access
architecture variants:
Independent architecture. Network slices
are logically completely isolated, and only
share physical resources. Each network slice
Mobile edge computing
Mobile Edge Computing (MEC) will significantly
close the gaps between the exsiting 4G systems
and services. MEC will facilitate the key step
of mobile network from single pipeline to the
integrated information services enabling platform
by means of pushing the service platform down
to the edge of the network which will offer
mobile users with service computing and data
caching capabilities locally. As one of the typical
5G network service, the core function of MEC
includes (in Figure-8):
1) Application and content within the pipe.
This function enables co-deployment of MEC
and gateway functions to build a flexible and
distributed service provision system and provide
optimal service running environment that is
especially suitable for local, low latency and wide
bandwidth services, such as mobile office, V2X,
4k-8K video, etc.
2) Dynamic service chaining. MEC function
will not be limited to simply sinking-down the
cache server only, but also to implement dynamic
service chaining by integrating the computing
function with forwarding nodes. Under the
unified scheduling of centralized control plane,
MEC can flexibly set the data forwarding paths
among multiple distributed service processing
nodes and provide a novel inner-network service
convergence model.
3) Network assistance function. Via tightly-
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coupled interaction with network control function
(for example MM or SM), MEC may optimal
its service capabilities further. For example, the
applications can be relocated to a more suitable
gateway which may support user mobility with the
network assistance to dynamically adjust the data
path. Service assistance also enables optimization
of control for applications based on network
contexts and users’ profiles.
The deployment of MEC functions can adopt
centralized way which is coupled with user plane
devices to enhance the gateway functions, or
distributed way at different locations and realize
service capabilities through centralized coordination.
Firgure-8 Mobile edge computing architecture
On-demand mobile network
reconstruction
The service objects of 5G networks are (a) different
types of terminals, applications, and session, (b) a
variety of mobility rules, and (c) widers spectrum of
security requirements. Consequently, it is difficult to
manage the network through a single mechanism. The
5G networks must be designed to seamlessly support
the requirements of different service scenarios. Hence
on-demand reconstruction of the network function is
one of the symbolic network services of 5G networks.
● On-demand session management
On demand session management means the 5G
network session management could base on the
device properties, user type, and service feature to
flexibly configure the parameters such as session
type, anchor position and service continuity. For
example, the always on-line mechanism in 4G
would become an optional features in 5G session
management.
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Users can select the session type according to
the service characteristics, for example, choosing
to support IP connectivity of Internet service;
using the control plane to transfer small data with
connectionless state; or customizing Non-IP private
session type for specific service.
The network can select anchor location and
transmission path according to the transmission
requirements. Network could select an anchor in
the central network and use tunneling mechanism
for the services which require high mobility. For
the interactive services, the optimal anchor could
be selected for both sides. For the service which
has requirement for the higher level of mobility,
SDN could be introduced to realize the flexible
programming for the user plane.
● On-demand mobility management
On-demand mobi l i ty management impl ies
maintenance of session continuity in active state
and reachable in idle state. Under the active and
idle mode, mobility can be divided into multiple
levels. By combining the two modes, and using the
service characteristics, the most suitable mobility
management model can be offered to the terminals.
The basic requirements for massive IoT sensors
and terminals are no mobility, high price-sensitive
and energy-efficiency. In response to this demand,
network does not detect whether the IoT terminal
is accessible when it is in idle state. Only when
the terminal wakes up and contacts the network,
the UL/DL data would be transferred in order to
save power. In the active state, the network could
simplify the mechanism for state maintenance and
session management, therefore the cost of terminals
could be reduced greatly.
In addition, the network can dynamically change
the terminal mobility level. For example, for some
vertical industry scenarios, the high mobility level
could be supported in a particular working areas to
ensure service continuity and rapid paging response.
When the terminal leaving the area, the network
would adjust the mobility level in a lower one for
energy efficiency.
● On-demand security
5G network will provide the different industries
with different services, hence the complete security
solution should be provided to meet the various
security requirements. For example, 5G need to
providing high-efficient, uniform and compatible
mobility security management mechanism for
mobile Internet access; 5G security could provide
the IoT network with more flexible and open
authentication framework and authentication
method and support the capability for new terminal
identity management; 5G security can provide
security for the network infrastructure. The security
isolation by setting trust boundary and protective
functions can be supported by the 5G networks for
the new network environment such as virtualized
networking and multi-tenant/shared network slices.
● Control plane restruction
Control plane restruction allows dynamically
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Firgure-9 Control plane restruction architecture
setting the network functions via modularizing the
network functions and decreasing the complexity
of the interaction among the network functions.
The network functions can dynamically discover
and connect to the required network functions,
and these network functions can be provisioned
and orchestrated on demand to address the diverse
network requirements. The function components
shown in Figure-9 may be helpful to achieve the
goal.
Neutral interface: the interface and interaction
messages between network functions shall be
reusable as possible, and one network function
(provider) provides its function and service
to other network functions (consumer) via
the same interface. Thus the legacy coupled
interface between the two specific network
functions turns into single neutral interface
provided by the network function (provider),
and the amount of the interfaces is greatly
decreased. The interconnection of network
functions utilizes the general communication
protocol which is independent with the
deployment location of network functions.
Converged network database: The network data
such as subscriber data, network provisioning
data and operator’s policy is stored in one
converged network database. Some context
data in the converged network database can
be shared among the network functions and
be accessed by the network functions via
the general interface in order to decrease
the interaction message among the network
functions.
Control plane interaction function (CPIF): CPIF
receives the messages from the network nodes
or the network functions which are outside
the control plane, and helps determine the
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User-centered RAN
5G RAN will change “Base station-Centered”
conventional design idea to the new “User Centric”
pattern, which, as shown in Figure-10, may include
flexible RAN control, context aware service delivery
and customized access network.
● Flexible RAN control
The real-time flexible radio processes and simple robust
radio link managements are required in order to achieve
“User Centric Cell”. Therefore, signaling functions and
control processes should be redefined as following.
Other than traditional coupled UE-Cell relation,
UE management and Cell management can be two
independent functions based on the principle of
decoupled UE and cell. The context and radio data
link of UE managed by UE Management Function is
decoupled from cells serving the UE; its serving cells
become a type of radio resources – cell domain radio
resource, similar to time domain, frequency domain/
code domain and spatial domain resources. The four
domains make up four-dimensional radio resource for
RAN scheduling. Each time, when RAN is to grant
a UE with radio resource, assuming deterministic
transmission time (time domain) resource, it will
first select cells (cell domain), and then determine
frequency domain/code domain/power domain, and
antenna selection related spatial domain resources
within the cells. Functions of RAN protocol stack
can be flexibly controlled or adapted to differentiated
link quality requirements and diversified physical
layer transmission technologies.
● Context aware service delivery
By introduction of mutual awareness between RAN
and application servers, RAN resource allocation
and application quality control (. video coding
rate adjustment) can be dynamically optimized and
matched, simultaneously improving radio channel
efficiency and mobile user experience. On the one hand,
RAN status information can be exposed to application
servers, . per UE available RAN throughput, based
on which more accurate bandwidth estimation and
therefore more precise quality control can be done by
application servers. On the other hand, application
related information can be delivered to RAN, . video
acceleration request, so that RAN can adjust application
control plane network function which handles
this message, then send the message to the
corresponding control plane network function.
CPIF also transfers the message from control
plane network functions to the network nodes or
the network functions which are outside control
plane.
Network funct ion reposi tory funct ion:
i t supports the regis t ra t ion of network
function when deploy the network function,
the discovery of network function during
operation, and monitoring of the network
functions during management.
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priority and resource allocation per service demand. It
is noted that, by intelligent perception of services, RAN
can also be capable to improve traffic routing efficiency,
achieving flexible traffic distribution and smooth traffic
steering across data gateways.
● Customized access network
Different from the network with “one-size-fits-
all” structure (., rigid protocol stack structure),
customized networks can adapt network configuration
and differentiate data processing according to
diverse service requirements in 5G, which will
bring significant benefits such as improving the
network performance and supporting effective rapid
deployment of new services, more effectively.
The use of SDP technique enables processing of
diverse services in a single RAN, in which customized
protocol functions are provided for service flows
with diverse requirements. By adopting SDP, when a
service flow arrives, RAN will identify (via service
awareness and identification) the requirements and
provide customized protocol function set for the flow.
For example, services with requirements of ultra-
low latency and high mobility (., the self-driving
car scenario), the protocol function set could contain
Firgure-10 User-centered RAN
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Network capacities exposure
A major issue facing the next-generation network
research are (a) optimization of user experience, and (b)
supporting the emerging business models seamlessly.
One of the capabilities of 5G network framework is
to expose network capacity to third-party users for
applications and services. This will enable applications
to take full advantage of network capabilities, and
achieve a better user experience and application
innovation. It will also helps optimize network
resources configuration and traffic management. The
following are the main characteristics of this feature (in
Figure-11):
Using the principle of separation of control and
forwarding functions, open framework based 5G
networks can support centralized control plane offering
a unified exposure of control functions.
At present in EPC, independent control functions are
distributed on different network elements. In order
to achieve the diverse requirements of the capability
exposure, capability exposure layer should be able to
manage various interfaces to acquire network capabilities
between its own and third-party network elements.
Hence, this feature introduces additional complexity in
architecture for capability exposure. 5G network control
functions are centralized, and it also simplifies interface
between open platform and third-party applications.
Using infrastructure based on virtualization platforms,
the capability exposure function of 5G networks help
optimize infrastructure resources management.
The use of rigid existing network hardware and
deployment in advance cannot meet the requirements of
functions, resources from different vertical industries.
The Exposure platforms interacting with MANO can
achieve exposure of virtualization features. Invoking
the NFVO/VNFM function, can help operator expose
network planning, deployment, update and scale
capacity to dynamically support customized network
services according to 3rd business needs. Calling
VNFM function achieves network element function
management. Calling VIM function to schedule CPU/
memory/network resources of network can help achieve
virtualization of network of resources and scheduling of
hardware resources in a unified fashion.
Using network computing platform at the edge of
the network, 5G networks exposure platform enables
seamless execution of 3rd business applications inside
the operator network.
5G network operations need to change the current
status of separated operation of network and service
functions. On the one hand, besides to be transmit
pipes, the network hopes to provide more value-added
services. On the other hand, applications can also
the mobility management and bearer management,
whereas some other protocol functions (., ROHC)
can be excluded to allow low latency. On the other
hand, for services with requirement of massive
connection, the mobility management can be turned
off.
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take advantage of networking capabilities to further
enhance the user experience. Based on the exposure
of business operation capacity, 5G network guides 3rd
business deployed inside operator’s network close to
user location. This helps 3rd businesses achieve both
high performance (., delay limit guarantee) and
high reliability. In addition, it reduces the threshold
of service deployment, and can be more convenient
for tracking network real time information (., user
location and network load), which helps to upgrade
user experience.
Finally, 5G networks produce large volume of record
data in real-time related to user behaviors, business
operations, and network operations, which are major
sources for big data analytics. Exposure platform
interacting with the data analysis center produces
more detailed analysis and offer greater value to all
concerned parties.
Firgure-11 Network capabilities exposure framework
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5G network architecture standardization work is related
with 3GPP SA2, RAN2 and RAN3.
Currently, 3GPP SA2 has established a study item called
NextGen (TR ), which is responsible for the Rel-
14 phase of 5G network architecture standardization.
Overall 5G network architecture standardization work
will be completed by Rel-14/15/16 versions.
IMT-2020 recommendations for 5G network architecture
of 3GPP SA2 are as follows:
In Rel-14, studys should focus on the 5G new
architecture features and in priority consider
such network functions as network slicing,
MEC, network function reconstruction, network
capability exposure, new interface and protocol,
and control and user plane separation, etc.
In Rel-15, normative work should complete
including basic architecture and prior key issues.
The study work for enhanced scenarios such as
enhanced policy control, critical communications
and UE relay can be kicked off.
In Rel-16, normative work for enhanced
architecture should be completed.
Standardization Suggestion
Meanwhile, IMT-2020 recommendations for 5G NR
RAN standardization are as follows:
Rel-14 covers study on NR key issues.
Phase I WI should focus on standardization points
of basic NR RAN existence, including LTE-NR
tight integration, NR function and protocol design,
RAN-CN interface and process, context aware
service delivery, etc.
Phase II WI should further study following key
points to enhance RAN capabilities and efficiency:
customized RAN, RAN function virtualization and
network slicing, self-organized RAN and related
technologies to enhance eMBB services and to
enable mMTC and URLLC services.
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In addition to the network architecture standardization
work above, the 5G network architecture involved in
security management, charging management, network
virtualization, network slicing management, will also be
promoted in the relevant standardization organizations
synchronously. In particular, in order to ensure that
the 5G network could be deployed in NFV platform,
ETSI NFV ISG needs to consider the 5G network
standardization process, and provide a commercial-
ready NFV-based telecom network platform.
Firgure-12 5G network standardization timeline
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To meet the challenges from the 5G extreme
requirements of experience, eff iciency and
performance, hold the new develop opportunities
of information industry in next decade, and
fulfill the strategic transition into the integrated
informat ion service enabl ing pla t form, 5G
network services need to be integrated with
services tighter and enhanced customization
capabilities further.
The 5G architecture design can be expanded into
two layers: system design for logic function and
networking design for deployment. Based on this
principle, 5G architecture finally can be present as
reasonable planes partition, on-demand function
composition, elastic resources management and
flexible networking deployment. The typical 5G
services can be summarized as: network slicing,
mobile edge computing, on-demand mobile network
reconstruction, user-centered RAN and network
capacities exposure.
Along with the 5G research and standardization wrok
5G getting further and more detailed, IMT-2020 (5G)
promotion Group is willing to strengthen cooperation
with global organizations, enterprises, universities
and research institutes to jointly shape the consensus
on the solution of 5G network architecture and
technologies and promote the globally unified 5G
network standardization and industrialization.
Conclusions
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Main Contributors
