5G Network Softwarization:

Key issues and Gap Analysis

Yachen Wang
2015.9
Agenda

Requirement, View and Key Issues

Consideration of Key Issues

Gap Analysis and Potential Work

5G Scenarios & Requirements
 5G scenarios and requirements are widely investigated and extended
like massive IOT, low latency and high reliability, and so on.
 It is hard for one traditional architecture to meet diverse scenarios in
cost-efficient and flexible way

4 scenarios
8 scenarios •Seamless wide-area coverage
•Broadband access in dense areas
•Broadband access everywhere •High-capacity hot-spot
•Higher user mobility •Low-power massive-connections
•Massive internet of things •Low-latency high-reliability
•Extreme real-time communications
•Lifeline communications
•Ultra-reliable communications
•Broadcast-like services
scenarios
•Ultra-reliable
3 scenarios •Mobile broadband
•Enhanced mobile broadband •Flexible and scalable
•Ultra-reliable and low latency communications •Wide-area
•Massive machine type communications •Vitural presence
•Real-time
•…
 5G Requirement: the Network Perspective

 IT technologies and Internet idea can be introduced to transform our

network to meet diverse scenarios
 Softwarization is a key concept to bring the simplicity, efficiency,
flexibility and openness to the network
IT and Internet Idea:
cloud, virtualization, Simplicity o Simplify the function/protocol/interface
SOA, agile, etc.

o Native IP packet for efficient forwarding

Efficiency o Centralized control and management

Softwarization
o Network function update timely, functions
can be composed and relocated in a flexible
Flexibility way
o Decouple access network and core network
to enable the independent evolution

Openness o Customers and service Oriented

o Network programmable
Towards the Design: 4D-Charistics

Design principle：based on IT technology based and new mobile

service oriented future network architecture

- Customized Service
o Network programmable , openness, network agility
- Modularized Function
o function atomization, modularization and composition per demand
- Virtualized Infrastructure
o Logical cell dynamic configuration.
o NFV for network functions
o Make the network more friendly for the cloud
- Centralized Management
o Manage and orchestrate the network service and functions
centralized
CMCC 5G Network Architecture

Network Capability Openness

Traffic
Access Mobility Session Policy Management&
Customized Management Management
Steering
&Data Orchestrator
Management Control
C-Plane
Function
NFV Platform

C/U Split
Service chain

D2D Data Charging

Video
Firewall
… Internet
Forwarding Optimizer

5G/2G/3G/4G/
WIFI
NFV Platform
Access Simplified U-Plane Function On-demand Service Function
provision

Control function Data function Data flow Control flow

 Enabling technologies

• New capability provided by

slice, service chain…
• Open API
• …
• Slice MANO
• Network Service Customized MANO • E2E
slicing
Coordination
• C/U Split
• Automatic
• Control plane Centra config
optimization lized,
Function Modularized
• U plane
simplification Collab
&Service orativ
chain e
...
Infrastructure

• E2E network programmable

• NFV/SDN
• …
Agenda

Requirement, View and Key Issues

Consideration of Key Issues

Gap Analysis and Potential Work

 Network slicing
Network slicing proposes the scalability and flexibility of network
architecture to support diverse scenarios
• Network slice is a End-to-end logically isolated network including 5G device,
access, transport and core network function. And these system functions
can be also shared in different slices
• Key issues:
• How to identify and select the slice in device, access and core part
• How to guarantee the end-to-end QoS of a slice
• How to design the slices to different scenarios

Core & area DC

Edge DC

Access
Infrastructure revolution and integrated MANO
 NFV/SDN transforms infrastructure into a manageable common platform
 MANOs should be enhanced to support distributed DCs, and the management and
orchestration across transport, DC, and IP network.
 Slices or its functions can be flexibly deployed anywhere and on demand.
M
Key issues CP
function
… A Core DC
• Slice lifecycle NFVI
N
O
mangement
Integrated
• Coordination of Manageme
MANO across nt &
network CP UP … M
CP UP … M Orchestrat
A A Area DC or
function function function function
N N
• MANO of NFVI O NFVI O
distributed DCs

UP M UP M UP M
… … …
function A function A function A Edge DC
N N N
NFVI O NFVI NFVI
O O

Access and backhaul

 C/U split, Control Plane Optimization and User plane Simplification

1. Control and user plane separation allows flexible deployment and scale
2. Control plane functions: Modularization and customization on demand
3. Data plane functions: function split and simplification, service chain based
function composition
Slice1 Access M Scenario 1
Massive
Function library Session M MTC
2 Modularization , like No
MME Mobility M Data mobility
sensors
Control Access M
MME S/PGW-C Access M
plane Scenario 2
Session M
S/PGW-C Mobility M Enhanced
1 C/U Split Data Mobile
GW-U … Session M broadband
charging Data
3 Slice2
TCP Opt.
User
… plane GW-U charing TCP Opt. Service chain1

EPC S/PGW equipment

Service chain2
control user

• Key issues
• Which protocol is better, GTP-C or openflow?
• How to design the atomic function for control function and
simplify the function, protocol and interface
 Network Capability Exposure
• A new Network Capability Layer: with resource orchestration, capability enabler to
achieve a highly efficient coordination between service and network
• Network capability exposure function will incorporate with new 5G architecture from
access to core network side
• Key issues
• Achieve an unified network
Application
Layer
OTT Enterprise MVNO capability exposure
architecture based on IT
Open API technology and new
mobile service requirement,
Exposure Adapt & Mangt.
Capability also compatible with 4G
Layer
network
Open APIs Mapping Capability
Deployme
Access
Control
Mashup nt Mangt. • Coordination of MANO to
build the network slices
Capability Enablers according to the 3rd party
Orchestrate Service Users & demand
Network
• Custom network functions
Policy
Network Chain Data
Controll
based on service chain
Resource Enabler Awareness

technology

Infrastructure
Layer Virtualized networks/platform

Physical infrastructure (network, computing and storage resources)

Agenda

Requirement, View and Key Issues

Consideration of Key Issues

Gap Analysis and Potential Work

Gap Analysis
• 5G architecture
– Some high level architectures had been proposed by NGMN, China IMT 2020, Part of
Vendors and etc.
– Absence of the detailed study on architecture functions design, interfaces and protocols
• Infrastructure revolution and integrated MANO
– ETSI NFV focus on NFV common architecture, function, and interfaces
– Absence of end-to-end coordination study
• Network slicing
– 3GPP SA2 Décor can not isolate the slices better
– Absence of RAN slice selection mechanism, slice MANO, Qos guarantee mechanism
• Function design
– Absence of overall design for each kind of network slice supporting a specific scenario
• Capability openness
– Absence of overall requirement, architecture, function study
Proposed work suggestions to ITU-T

• Network slicing: Study on design principles of architecture

and functions in a network slice serving the specific scenario
• QoS of network slice: Study on QoS mechanism of network
slice considering that it could be customized and opened to
third party
• 5G network exposure: Study on the new requirements,
architecture, functions and open API of capability exposure,
and potential solution for each capability
Some Work in CMCC

From 2013, Proposed SAME(Softnet Architecture for Mobile) with the

features of C/U split, Gi service chain, control plane optimization and
NFV-based infrastructure

Prototype and
Standardization
Demo
1. Develop prototypes 1. CCSA: finish SAME study item, 2014
with C/U split and 2. ONF: propose C/U split requirement，2014
3. NGMN: involved in architecture design and
service chain features
principles of 5G white paper, 2014——
(with Huawei, ZTE) 4. China IMT-2020 Group: lead the network
2. Demo the prototypes technology subgroups, 2014——

in 2015 MWC 5. 3GPP: initiated C/U split of gateway study

item,2015
(Barcelona &
6. ITU: launch and lead SAME requirement and
Shanghai) co-lead IMT 2020 Focus Group work，2015
Thanks