Special Feature: Video Communication Technology

Video Communication Technology forResonant Communication
Tatsuro Murakami, Satoshi Hayama, Takashi Yoshida,and Satoshi Ishibashi†
Abstract
As part of its overall strategy to expand broadband and ubiquitous network services, the NTT Grouphas developed a multipoint video communication service that features high-resolution picture quality,
ease-of-use, and affordability. This service was launched commercially in March of this year. It offers
convenient carrier-grade videoconferencing and videophone functions and can be used in the same way
as IP-phone services.

1. Targeting the expansion of broadband services
With the rapid expansion of broadband IP (Internetprotocol) communications made possible by the diffusion of fiber-optic access, major service developments are not limited only to the improvements inInternet access. IP telephones and video content
viewing have now reached the same level of quality
and usability as traditional telephones and televisions.
Based on the “Resonant Vision” announced in 2003[1], NTT Laboratories and NTT Resonant are committed to creating attractive services for the fiberoptic age. Specifically, we are developing a videocommunication service, and based on it, we aredeveloping and providing new business applications.
One such initiative is our development of the PC
Communicator (PCC), which makes possible highresolution, easy-to-use, affordable multipoint videocommunication among personal computers (PCs).
NTT Communications introduced “OCN Dot Phone[.Phone] Business V” in March of this year. This is acommercial service that runs on the OCN*1 servicesof NTT Communications and is targeted at SOHO
(small office, home office) and corporate customers.
NTT Resonant designed, built, and now operates this† NTT Resonant Inc.
Chiyoda-ku, 100-0004 JapanE-mail: reso-pro@lab.ntt.co.jp

12service, which it provides to NTT Communications
as a service function, i.e., on a service wholesaling
basis. Another significant feature of this system is its
connectivity with NTT DoCoMo’s FOMA*2 videophones, which makes it a ubiquitous service suitablefor practical use.
2. Video communication
NTT Group’s vision for broadband and ubiquitous
service evolution is presented in Fig. 1. As part of thisvision, we are developing and offering realtime, highly natural video communication services that support
multipoint videoconferencing. This system leveragesthe ultrafast interactive video services made possible
by fiber optics and connections to mobile communication services. While drawing on the combined
strength of our corporate group, we will continue tomeet the ever more demanding needs of our customers by developing and providing dependable,easy-to-use portal services. Through the blending ofservices, we aim to respond flexibly to the needs of*1 OCN: open computer network. An Internet connection service provided by NTT Communications. OCN provides broadband Internet connection, contents delivery, and “.phone” IP telephony services etc. (http://www.ocn.ne.jp/english/personal/option/voip/).
*2 FOMA: A third-generation (3G) mobile communications service
operated by NTT DoCoMo that provides videophone and highspeed data communications (http://www.nttdocomo.com/corebiz/network/3g/index.html).

NTT Technical Review

for Resonant Communication

Seamless services that can be used by both broadband and mobile devices
Portal, contents, applications
E.g., integrated group portal, advanced area information service,e-learning system
Platform
E.g., ID integration between site services
Communication services
E.g., video communication service, multipoint video communication
service, convergence of fixed-line and mobile communication services

3G mobilephone network(FOMA)

Broadband(optical fiber)

Wireless LAN

Seamless devices that can be used anywhere
Dual devices, wireless communication between devices, etc.
3G: 3rd generation
FOMA: NTT DoCoMo’s mobile phone service

Fig. 1. Evolution of broadband and ubiquitous network services.

Examples of using high-resolution interactive video
A videophone service that allows the sharing of informative materials enables a financial institution
to offer high-quality, expert consultating services (e.g., life planning simulation and life/accident
insurance consultations) across all of their branches.

CustomerLong-distance consultationCounseling
The ability to immediately share simulation
results promotes smooth sales consultations

Consulting

Call center
Areas forapplication
expansion

AdviceDistance legal
consultations

B2C applications

Distance healthconsultations
Specialists

Sales agents
Sales assistanceIn-company
education

Distance tax
planning
consultations
Distance real-estate
consultations

IP network

Distance private
lessons

Products inquiries
Sales assistance

Inquiries
Internal business & B2B
applications

Fig. 2. Examples of videophone usage.

our customers.
Videophone and videoconferencing services arerepresentative video communication services madepossible by PCC. Some examples of videophone uses
are shown in Fig. 2. High-speed video transmission
Vol. 3 No. 10 Oct. 2005

makes possible high-resolution video and interactivity: this allows non-verbal visual cues such as facial
expressions to be exchanged, which is not possible
with voice-only calls. For consulting services whereface-to-face interaction is critical (e.g., legal, health13

Special Feature

Examples of easy-to-use, stable multipoint communication
Teleconferencing between main and branch offices cuts travel times and costs
Participants base discussion
on shared material
Areas for application
expansion
Long-distanceconference
Remote working
from home
Distance education
Distance healthcare
Sign language
interpretation
Hobby/cultural groups
IP network
Head
officeOpticalfiber

BranchofficeBranchofficeBranchOpticalofficefiber

One-to-one confirmation ofviewpoints during meeting

Fig. 3. Videoconference.

care, tax, and real-estate counseling), the videophoneservice enables sensitive customer care. The fact that
PCC allows explanatory materials to be shared to aid
in discussion further promotes a deeper communication with the customer.
Some usage scenarios for the videoconferencing
service are shown in Fig. 3. The service allows multiple participants, separated by long distances, to holddiscussions as if they were in the same room. Communication and understanding is enhanced by features such as the document sharing function, whichallows the display of materials to all participants, andthe whiteboard function, which allows participants tocooperatively draw out ideas on a shared virtual
whiteboard.
Although videoconferencing services are alreadyavailable over ISDN and dedicated lines, there areissues related to video quality as well as equipment
and transmission costs. Broadband IP transmission
over optical fiber access lines overcomes all theseproblems, making multipoint video communicationeasy and affordable.
Furthermore, the integration of fixed-line andmobile access makes it possible for users to participate in videoconferences via FOMA mobile phones.
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This is handy in situations where quick decisions
need to be made remotely: the on-site conditions canbe communicated through the videophone and quick
feedback or decisions can given by the central office.
3. Carrier-grade video communication service
An overview of the video communication service
using PCC is shown in Fig. 4. PCC offers carriergrade service, which NTT is well-positioned to provide.
The PCC system provides QoS (quality of service)
management capabilities, making it possible for us tooffer a high-quality, reliable service with quality andreliability levels equivalent to those of traditional
phone services. Connection and transmission management between the video clients is done using SIP(session initiation protocol), the protocol used by IPphone services. Each PC client can be assigned an050 telephone number, which makes authentication
possible. The PCC system is flexible enough to copewith further developments in convergence. Flexible
billing to support various types of service models ispossible. The system also supports interconnectivity
with analog and IP phones and video communication
NTT Technical Review

Special Feature

PCC combines various communication tools such as videophones and videoconferencing into a single system.
It makes possible a variety of video communication methods from a PC.
PC
VideoconferenceVideophone(PC only)
PCFOMAFOMA (option)
Communi- Communicating
cationpointsmedium• Multi-location
conversations
enabled by audio-mixing
functions
Multipoint

1:1

Video communication Voice communication
functionfunction

Details

Video- • Convenient hands-freeconversation enabled by PC
confeecho-canceller
rence• Videoconference
between as many as 20
locations with high-quality
MPEG-4 video• Area-free videophone(unrestricted by location
limitations) made possible
by communication between
PC
FOMA videophones andPC conferencing clients• Facial expressions andVideoatmosphere communicatedphoneby high-resolution video• Highly realistic sensation ofpresence created between
participants despite the distancePCby fundamental functions
needed for meetings such as
application sharing board andfile transfer

Sound mixing

Sharing of presentationmaterials/chatting

Echo-canceling

Application sharing

Sound quality equivalent
to fixed-line phones

Whiteboard

Hands-free talking

Participation byFOMA devices (option)

PC
MPEG-4 high-quality
pictureVideoconferencePC
Up to 20 participating
pointsFOMA(option)

Videophone

FOMA

Otherfunctions

Videophone callbetween PC and FOMA

Sound quality equivalent
to fixed-line phones

MPEG-4 high-quality
pictureHands-free talking

File transfer
Videophone

PC

MPEG-4 high-quality
pictureSound quality equivalentto fixed-line phones

Application
sharing board

Hands-free talking
Instant messaging

Fig. 4. Service overview.

with FOMA videophones. The main functions supported by PCC are described below. Some of thesefunctions are described in more detail in the otherarticles in this Special Feature.
(1) Videophone
The videophone has an 050 telephone number justlike an IP telephone. It uses MPEG-4 encoding forhigh-resolution video communication. The phone canalso be used as a standard IP phone making voice
only calls to analog and mobile phones. Video-calls
to FOMA videophones are supported.
(2) File transfer
During the videoconference, files can be transferred to specified participants (file size: up to 100MB).
(3) Application sharing board
Two people may share a window where text can beVol. 3 No. 10 Oct. 2005

entered and shapes can be drawn. Both users cansimultaneously view the same whiteboard and sketch
on it.
(4) Instant messaging
Two people can send text messages in real time.
The text is automatically saved, so it can be referred
to after the chat conversation.
(5) Videoconferencing
Up to 20 people at a time can participate in a videoconference. The system incorporates a high-performance echo-canceller, so users do not need to use
headsets: they can hold natural conversations using
ordinary microphones and speakers.
Because the voice mixing function continuously
sends and mixes the sound from all conference participants, any participant can speak at any time, justlike in a real meeting. While holding a conversation
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Special Featureusing video and voice transmission, users canexchange instant messages and use the whiteboard.
Participation in the videoconference by FOMA
mobile phones is also supported.
(6) Conference schedule registration
The videoconference time and participant list canbe set from a Web browser. Once the time for the conference has been reserved, an email invitation is sentout to all participants.
(7) Sharing of materials
During a videophone call or a videoconference, it ispossible to share documents (e.g., Excel and Powerpoint files.) among all the participants.
(8) Application sharing
An application on one participant’s PC can beshared by all of the participants. This is handy forjoint editing of materials or cooperative softwaredevelopment.
(9) Whiteboard
During a videoconference, participants can freely
draw onto the virtual whiteboard using standard writing implements such as pencils. Multiple participants
can draw simultaneously on the same whiteboard.
(10) Address book
A user can register participants in his/her own
address book. This makes it easy to search for users
by their name or phone number when one wants to setup a videophone call or videoconference.
(11) Active list (presence)
A user can check the presence of persons on his/her

Network of wholesalecustomers
Presence
serverSIP
PSTN-GW server

registered list, where presence means that the person
is currently online(12) Call history
A user can view his/her transmission history log forvideophones, videoconferences, and instant messaging and view the content of the instant message chats.
4. System architecture
The overall architecture for this system is presented in Fig. 5. The blue parts represent the PCC system,
which has three main types of functions. These aredescribed below and summarized in Table 1.
(1) SIP proxy and presence functions
Connection management of clients is done using
the SIP protocol. Presence information for all registered clients is managed. This portion also includes
authentication and billing functions.
(2) Videophone and videoconferencing functions
These are composed of a number of objects including the multipoint videoconference server, whichmakes it possible for multiple clients to simultaneously connect for conferencing, the document sharing server, and the gateway to the FOMA network.
The client is an ordinary PC with special software
installed.
(3) Operations functions
User registration and overall maintenance andoperations are performed via the system console.

Operation function
Operationssystem
Presenceserver
SIPserver
SIP proxy/presence function

IP telephone

ClientIP videophoneclientOverseas
telephone
network

Videophone/
videoconferencing
function
Multipoint
videoconferencing
serverNetwork of service
wholesaler

FOMA-GW

Videophone/
videoconferencing
function

IWEFOMAnetwork
PDC network

PSTN network

FOMA terminal
PDC terminal

PHS network
Subscriber telephone

PHS terminal: PCC system

PSTN: public switched telephone network
GW: gateway
IWE: interworking equipment
PDC: personal digital cellular
PHS: personal handy-phone system

Fig. 5. System architecture.

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NTT Technical Review

Special Feature

Table 1. Overview of functions.
SIP proxy andpresence functions

Videophone andvideoconferencing
functions

SIP server

SIP session control function

Presence server

Function for managing conference terminal’s presence and profile information

Multipoint videoconferencing server

Multipoint conferencing basic functions (user management, conference
reservation management, voice synthesis, video distribution, etc.), functions
for sharing presentation materials among conference participants, etc.

ClientClient software installed on PC for videophone and videoconferencing functions

FOMA-GW
Operations functions

Gateway for connecting to FOMA videophones
Functions related to maintenance and operations performed via the console

5. Future plans
PCC, the video communication service presented
in this article, was developed to offer videophone andvideoconferencing services to small enterprises.
Next, we plan to build a system that can serve a wide

range of customers in various usage scenarios.
Reference[1]“Next Generation Network—RENA,” NTT Technical Review, Vol.
1, No. 6, pp. 48-61, 2003.

Tatsuro Murakami

Takashi Yoshida

Executive Research Engineer, NTT Service
Integration Laboratories.
He received the B.S. and M.S. in physics from
Tokyo Institute of Technology, Tokyo in 1979
and 1981, respectively. He joined Musashino
Electrical Communication Laboratories, Nippon
Telegraph and Telephone Public Corporation(now NTT) in 1981. He has been engaged in
R&D of communication network architecturesand communication switching software. From1984 to 1986, he was at NTT Basic Research Laboratories, where he researched formal description
methods for service specifications. From 1987 to1990, he was at NTT Software Development
Center, where he was active in the developmentof NTT’s switching system (called D70) software. From 1991 to 1997, he was involved in
R&D of a software development environment forcommunication switching systems at NTT Network Service Systems Laboratories. From 1998
to 2001, he was active in the development of thenew signaling transfer point for NTT’s SS7 network and R&D of VoIP systems at NTT Network
Service Systems Laboratories. He is currently
working on establishing NTT’s next-generation
communication network architecture and planning the overall R&D strategy for NTT’s nextgeneration communication networks. He has
been a member of the Multiswitching Forum
Board of Directors since 2002.

Senior Manager, Core Networks Business
Headquarters, NTT Advanced Technology Corporation.
He received the M.E. degree in applied physics
and engineering from Tohoku University,Sendai, Miyagi in 1978. In 1978, he joined theElectrical Communication Laboratories, Nippon
Telegraph and Telephone Public Corporation(now NTT), where he engaged in research onapplications of speech signal processing intelecommunication network systems such asvoice store & forward systems, customer contactsystems, and distance learning systems andresearch on voice and video communication services over IP networks. He moved to NTT
Advanced Technology Corporation in 2005 andis responsible for IP network applications business.

Satoshi Hayama
Senior Research Engineer, NTT Cyber Solutions Laboratories.
He received the B.S. and M.S. degrees in engineering from Tohoku University, Sendai, Miyagi
in 1981 and 1983, respectively. He joined Nippon Telegraph and Telephone Public Corporation (now NTT) in 1983 and has mainly been
engaged in R&D of communication processing
systems, OCN service providing systems, andInternet digital video content distribution systems.

Vol. 3 No. 10 Oct. 2005

Satoshi Ishibashi
Senior Manager, Communication Service
Division, NTT Resonant Inc.
He received the B.E. and M.E. degrees in information engineering from Tokushima University,
Tokushima in 1980 and 1982, respectively andthe Ph.D degree in electrical engineering fromTokyo Institute of Technology in 1992. In 1982,
he joined the Electrical Communication Laboratories, Nippon Telegraph and Telephone Corporation (now NTT), Kanagawa. From 1989 to1991, he worked in ATR Communication Laboratories in Kyoto. He has been engaged in R&Dof picture coding systems and visual communication services. He moved to NTT Resonant Inc.
in 2004. He is a member of the Institute of Electronics, Information and Communication Engineers of Japan, the Institute of Image Informationand Television Engineers, and the Institute ofImage Electronics Engineers of Japan.

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