5G Mobile Communication

Networking Technology

Professor WANG Jing

Tsinghua University, China

wangj@tsinghua.edu.cn

2013.07.17.

Outline

Future Requirements

Technology Developments

Hyper-cellular Architecture

Conclusions

Future Requirements

Future Requirements

Mobile terminal market

Mobile Service Market

Over 3 billions of Laptops, Pads and Smart phones

Over 5 billions of download applications

Mobile data traffic is doubled

every 13 months

Requirement Forecast

Total subscriber base increases

10% YoY

Mobile broadband penetration to

reach 100% by 2020

Traffic volume per subscriber

increases 25-40% YoY

Traffic volume increases by:

x150-500 from 2010 to 2020 and

x3000-30000 from 2010 to 2030

The 1000x data challenge (ref 2010) may likely happen during the period 2022-2026

Technology goals of the 5G

METIS Project Objectives

• C5G Project Objectives • Area Data Throughout of 25 times Improvement to 4G

• Frequency Efficiency of 10 times Improvement to 4G

• Service Data Throughput of 10Gbps

• Energy Efficiency of 10 times Improvement to 4G

Technology Developments

Air Interface Technologies

1990 1995 2000 2005 2010 2015 2020

GSM GPRS EDGE EDGE+ Evolution

UMTS HDPA HSPA+ UMTS-A

LTE LTE-A LTE-B LTE-C

GMSK+CC +TDMA QPSK+TC +CDMA QAM+OFDM+MIMO New Air Interface

4G

3G

2G

??? 5G

Transmission Technology Contributions

MIMO ICIC

Where are

we going to?

System Architecture Evolution

R99R5R8 (3GPP)

From Tree to full mesh

Coverage Limitations

Environment Downlink

(bit/s/Hz)

Uplink

(bit/s/Hz)

Indoor 0.1 0.07

Microcellular 0.075 0.05

Base coverage

urban

0.06 0.03

High speed 0.04 0.015

Environment Downlink

(bit/s/Hz)

Uplink

(bit/s/Hz)

Indoor 3 2.25

Microcellular 2.6 1.80

Base coverage

urban

2.2 1.4

High speed 1.1 0.7

Average frequency efficiency

Frequency efficiency of cell edge

Small Cell Limitations

Cell size

Capacity (users/MHz/km2)

• Path loss exponent decreases with

reducing cell size because of LOS

happening more

• Inter-cell Interference increases

Significantly with Decreasing of Path

loss exponent

Network capacity does not improve

Continuously with decreasing cell

size because of ICI

Possible Solutions for 1000x

3x increase in spectrum

Re-farming Existing bands for more efficient use

New licensed bands, including higher frequencies for hot-spot

6x improvement in spectral efficiency

Higher-order modulation to 256QAM to increase the amount of data transported per

Hz of spectrum

3D MIMO and massive antenna beam forming with arrays of as many as 100+

antenna elements

Coordinated multiple point transmission and interference management techniques to

improve cell-edge performance

56x higher average cell density in HetNet configurations

The addition of many layer cells including macro, micro, pico, femto, relay,

phantom, ……

Traffic Balancing and offloading of many modes including 2G, 3G, 4G, 5G,

WiFi, ……

Clouds of antennae will provide the biggest boost to capacity through extreme

frequency reuse.

Source：http://www.wiseharbor.com/index.html

ICI Cancellation Performance

• 4X4 MIMO

• 20MHz Bandwidth @ 3.5GHz

• APs(antennas only) connect Computing

Unit by RoF

古北路

虹古路

芙蓉江路

仙 霞 路

运动场

档案馆

AP1 AP2

MT

only

only

AP1+AP2 CoMP

Source: China FuTURE Project

Lessons learnt from Past 40 Years

Source: http://www.arraycomm.com/technology/coopers-law

Sp

ectr

al E

ffic

iency x

25

Spectrum Employed x 25

•TACSGSM：4 times（2G）

•GSM UMTS：2.5 times（3G）

•UMTS LTE：2.5 times（4G）

Network density improves system capacity of 60

times compared other domains.

5G Technologies should Enable ‘Net Work’

CoMP: ICIC Algorithm + Architecture

Cell Density: 250m33m Small cell, phantom cell

HetNet: layers and modes

Mobility: Handover：horizontal and vertical

Connectivity：always online

Hyper-Cellular Architecture

Hyper-Cellular Architecture (HCA)

Separating the Coverage of C-Plane and D-Plane

Seamless coverage of C-Plane/U-Plane

Soft coverage of D-Plane

Soft access mode matching

Unified Signaling Procedure of diverse systems

D-Plane Implemented by Distributed Wireless

Communication Systems (DWCS)

Virtual Node-B

Virtually Cell

Separating the Coverage of

C-Plane and D-Plane

The decoupling of the control signaling coverage and traffic data

coverage

Coverage Example

Soft access mode matching

Unified Signaling Procedure of diverse systems

GSM 900MHz

LTE 3.5GHz

WiFi 2.4GHz

D-Plane

C-Plane

DWCS Based D-Plane

Node C3 Node C4

Node C1 Node C2

Cable/Fiber

Node A

MT1

MT2

Elements in DWCS

NodeA: Antenna Units Interfaces between air and fiber

NodeC: Computation Units Modems, filters,…

Connection Between NodeA and NodeC High performance mashed network

Virtual NodeB=NodeAs+NodeC MT oriented Processing

Virtual Cells MT oriented coverage

2013/8/27 23

Inter-Antenna Interference Cancellations

under DWCS

MTs with WCDMA voice

10 20 30 40 50 60 70 80 90 100 110

1E-4

1E-3

0.01

0.1

1

m=1,=3

m=2,=3

m=4,=3

m=1,=4

m=2,=4

m=4,=4

Ou

tag

e p

rob

ab

ility

Number of mobiles per antenna

Source: IEEE Communication Magazine, 2003

DWCS Example – C-RAN

C-RAN is proposed by the China Mobile (CMCC)

Baseband processing is Centralized logically

Radio processing is Cooperative

Computation Units is real-time Cloud

Systems is Clear (Green ), energy saving systems

C-RAN Construction

X2+

… …

PHY/MAC

RRU RRU

RRU RRU

RRU

RRU

RRU

RRU

RRU

X2+

BBU Pool BBU Pool BBU Pool

负载均衡

高速交换

PHY/MAC PHY/MAC PHY/MAC PHY/MAC PHY/MAC

Fiber Transmission

Distributed RRU

Cooperative

Radio

Real-time Cloud

HCA Advantages

Connection Suitable for Diverse RANs

Different operation modes: 2G, 3G, LTE, WiFi, ……

Different coverage layers: Macro, Micro, Pico, Femto,

Relay, Phantom, ……

Different AI constructions: eNodeB, NodeB, DAS, C-RAN,

DWCS, ……

Energy Management: AP on/off, Power control, ……

Good Performance

Good Connectivity & Mobility

Flexibility, Scalability, Cost & Energy efficiency

Challenges of HCA Realization

Optimize Coverage of C-Plane

Unified signaling capacity

Special services in U-Plane

Optimize Coverage of D-Plane

Service oriented

UE oriented

Energy oriented

Redefine Radio Resources

Time slot, frequency band, location, beams, mode, layer, etc.

Redefine the signaling procedure

Defining Cell-ID, Synchronizing, Accessing, Handover, Paging,

Power control, Radio resource management, etc.

Challenges of DWCS Realization

High Quality Network

Broad band up to Tbps

High timing accuracy reach ps

Full meshed connection

High Performance Computing Units

Reconfigurable

Scalable

Reliable

Real-time Cloud

Conclusions

Networking technologies play an

important role in the 5G systems

The Hyper-Cellular architecture splits

coverage of signaling and data to meet

the evolution of mobile networks

DWCS can meet requirements of radio

technology evolution