3.5GHz Development in DOCOMO

Hiroyuki Atarashi
Radio Access Network Development Department
NTT DOCOMO, INC.

© 2016 NTT DOCOMO, INC. All Rights Reserved.

Introduction (1)• The 3.5GHz band was licensed to three Japanese
mobile operators in December 2014
Assigned spectrum (40MHz each x 3 operators)

NTT DOCOMO
3456

3400
Microwave links for broadcasters

3480

KDDI3520

Softbank
3560

3600
(MHz)

To be licensed until November, 2022

Satellite systems• Several technical requirements were specified:– LTE-Advanced (TDD)– Requirements for base station deployment, such as more than 50% ofthe population coverage– Application of technologies for efficient utilization of spectrum, suchas carrier aggregation, adaptive modulation, etc.
© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

2

Introduction (2)• NTT DOCOMO launched the 3.5GHz commercial
service in June 2016
• This presentation provides overview of:– DOCOMO’s 3.5GHz technology development– DOCOMO’s 3.5GHz commercial service© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

3

DOCOMO’s3.5GHz technology development© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

4

“Advanced C-RAN architecture” concept• DOCOMO’s proposed RAN architecture
concept for LTE-Advanced– Integration of “Carrier aggregation (CA)” and“Small cells” using “C-RAN architecture”
Macro cell
(FDD)

Optical fibers

RH

BBU
RHCA
© 2016 NTT DOCOMO, INC. All Rights Reserved.

Small cells(3.5GHz TDD)

RH

RH
RH

RH

CACACA© 2008 NTT DOCOMO, INC. All rights reserved.

BBU: Based-Band Unit, RH: Radio Head5

Advantages of “Advanced C-RAN architecture”• Suitable for small cells deployment providing:– High data rate and high-capacity network– Good mobility performance

Data rate

CACA

With Advanced
C-RAN architecture

Always connected to macro cell & High data rate in small cells
Data rate

Without Advanced
C-RAN architecture© 2016 NTT DOCOMO, INC. All Rights Reserved.

HandoverHandoverHandover© 2008 NTT DOCOMO, INC. All rights reserved.

Handover6

Developed RAN equipment for 3.5GHz• Various deployment scenarios are supported
For macro cells

BBU
Antennas

RH

GPSFor indoor

Antenna

RHFHM© 2016 NTT DOCOMO, INC. All Rights Reserved.

For small cells

Antennas

RH© 2008 NTT DOCOMO, INC. All rights reserved.

NW synchronization

FHM

7

Base Band Unit (BBU)• Up to 48 cells can be accommodate to realize“Advanced C-RAN architecture”• This BBU can accommodate 3.5GHz-cells as well as
existing FDD frequency bands’ cells• Combination of different vendors’ BBU and RH ispossible (i.e., multi-vender solution)© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

8

Radio Head (RH) for 3.5GHz• Two types of RH for different scenarios– RH for 3.5GHz small cell & indoor– RH for 3.5GHz macro cell in suburban/rural scenarios
For macro cells

For small cells/indoor• 0.48W/20MHz/branch• Less than 4L© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

• 19W/20MHz/branch• Less than 9L9

Antennas for 3.5GHz• Different types of antennas have been developed
for different deployment scenarios

For small cells© 2016 NTT DOCOMO, INC. All Rights Reserved.

For indoor© 2008 NTT DOCOMO, INC. All rights reserved.

For macro cells

10FrontHaul Multiplexer (FHM)• A FHM distributes & combines a maximum of 16 RFsignals on the fronthaul• It can provide a economically efficient solution toserve different areas as a single cell
FHM

BBU

FHM
© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

FHM
11

Further details• Further details can be found in “SpecialArticles on Introducing the 3.5-GHz Band”
in “NTT DOCOMO Technical Journal”– NTT DOCOMO's Efforts Concerning Technical Developmentsfor Introducing TD-LTE in 3.5-GHz Frequency Band
– Base-station Equipment with the Aim of Introducing 3.5-GHzband TD-LTE– Base Station Antennas for 3.5-GHz Band
– High-precision Clock-time-synchronization Network Equipment forIntroduction of 3.5-GHz band TD-LTE– Router-type Mobile Terminal for TD-LTE in 3.5-GHz Band

© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

12

DOCOMO’s
3.5GHz commercial service© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

13

Japan’s first 3.5GHz commercial service• 370Mbps service using the 3.5GHz band– Launched in June 2016 in 35 cities across Japan– Currently, expanded to 50 cities across Japan*
Maximum
110Mbps

3.5GHzMaximum
110Mbps

1.7GHzMaximum
150Mbps

Aggregation

3.5GHzMaximum

370Mbps* Other than Tokyo, Nagoya and Osaka, 332.5Mbps service using 3.5GHz is available in 32 cities
across Japan© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

14

Planned further enhancement
FY 2014

2016

2015

2020

5G
• Service will be enhanced to682Mbps using 4x4 MIMO & 256QAM ~1Gbps
682Mbps

300Mbps
225Mbps© 2016 NTT DOCOMO, INC. All Rights Reserved.

3CCusing FDDbands

3.5GHzTDD+FDD

3.5GHzMaximum
241Mbps

3.5GHzMaximum
241Mbps

1.7GHzMaximum
200Mbps© 2008 NTT DOCOMO, INC. All rights reserved.

Aggregation

PREMIUM 4G

375Mbps

370Mbps

3.5GHz TDD+FDD
4x4 MIMO
256QAM

Maximum

682Mbps15

Thank you for your attention© 2016 NTT DOCOMO, INC. All Rights Reserved.

© 2008 NTT DOCOMO, INC. All rights reserved.

16