Special Feature

Home Network & Networked ApplianceTechnology
Hisashi Ibaraki†
Abstract
This article presents an overview of an adaptable platform for integrating applications and services using broadband access in the homethat opens the way to innovative solutions by linking networks and services and by linking services to other services. It also describes recent
appliance-related developments that have inspired new services anddiscusses research and development directions in this area.

1. Background trends and development issues
1.1 Deployment of broadband access
The growing popularity of mobile phones capableof connecting to the Internet has pushed up the number of Internet users to 80 million, close to 60% of the
population. Especially remarkable is the number ofcontracts of broadband access (DSL, cable Internet,
FTTH, wireless, etc.), which reached the 15 million
mark by the end of 2003 (DSL: digital subscriberline, FTTH: fiber to the home). Considering that eachcontract represents several users, it is estimated thatsome 33.7% of Internet users are broadband accesscustomers.
The rapid emergence of this broadband access is
closely related to the national IT and ICT-related
strategies (IT: information technology, ICT: information and communication technology). Japan’s pioneering e-Japan Strategy of 2001 elevated the deployment of a broadband infrastructure to the highest priority. The plan called for an environment that would
support up to 30 million high-speed Internet subscribers and 10 million super-high-speed Internet
subscribers. This target environment itself has
already been achieved.
After 2003, this was followed by a succession of† NTT Cyber Space Laboratories
Yokosuka-shi, 239-0847 Japan
E-mail: ibaraki.hisashi@lab.ntt.co.jp

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initiatives including e-Japan Strategy II seeking totake fuller advantage of IT technology, the e-Life Initiative promoting commercialization and wider use of
networked appliances, and the u-Japan Initiative fostering the ubiquitous information society. The point
to be emphasized here is that, although an infrastructure that could accommodate up to 40 million broadband access contracts was put in place, the actual
number of contracts did not exceed 15 million. In
other words, this environment is currently being
under-utilized. This under-utilization can be attributed to the fact that services have not reached a levelthat is completely satisfactory, which highlights theimportance of issues such as how the infrastructure
can be better utilized and how services can be better
tailored to the needs of users.
Let us first review the types of services that havebeen proposed. The e-Japan Strategy II initiative
focuses on seven key areas where IT can be more
effectively utilized:• Medical services: promote more widespread useof electronic receipts, etc.
• Food: develop traceability systems, etc.
• Lifestyle: develop home health management systems, etc.
• Small and medium enterprise financing: promoteassignment of obligations by electronic means,etc.
• Knowledge: promote e-learning, etc.
• Employment and labor: provide better employNTT Technical Review

Special Feature

ment information through public-private collaborations, etc.
• Public services: construct and deploy portal sites,
etc.
Based on this initiative, considerable research anddevelopment is focusing on technology leveraging IT
in these seven key areas, which all have a direct
impact on the general public.
Let us next look at the objectives of the e-Life Initiative, which is seeking to promote more widespreaddissemination of networked appliances. In contrast to
the old materialistic three ‘C’s of the 1960s (car, cooler, and color TV), the new three ‘C’s that are the foundation of the strategy for disseminating networked
appliances are concerned with the less tangible areaof information. The new three ‘C’s are:• Communication: effective utilization of communication between family members and between
business people in the home and office and outdoors• Control: implementation of user friendly andeasy-to-operate networked appliances• Content: effective utilization in content-related
businesses, education, and life-long learning
1.2 Growing number of networked devices
We have seen a shift in emphasis of R&D of home
networks and appliances to focus on research of
appliances and devices that can be connected totelecommunication networks and home networks andthe development of services enabling all thesedevices and appliances to be operated as a single system. Indeed, considerable progress has already been
made in developing and refining a range of different
kinds of appliances. Here, I will take a closer look at
three categories of devices: information-communications equipment, audio-visual (AV) appliances, andwhite goods and environmental appliances.
(1) Information-communications equipment
Information-communications equipment, which
has always involved network connectivity, is nolonger the simple communication tool it once was.
The R&D emphasis has now shifted to linkages withdifferent media (media centers supported by media
servers), endowing phones that used to support only
speech with Internet connectivity, and enabling linkages with the Web and email (NTT DoCoMo’s imode and NTT East&West’s L-mode). In this area,
the convergence of different functions has become amajor trend, and one important issue is how to makenew terminals that combine different functions moreuser friendly and easier to use.
Vol. 3 No. 6 June 2005

(2) AV appliances
Although they have never been networked in thepast, AV appliances such as TVs and audio equipment can utilize all the rich content on the Internet if
they are given the ability to interconnection with networks. And with HDD (hard disk drive) and DVD
players being operated as broadcast servers, we arealso seeing a trend toward seamless sharing of content between broadcasting and communication.
(3) White goods and environmental appliancesInterconnecting white goods to the network opens
up the possibility of all sorts of novel uses. For example, one can download a recipe to a microwave ovenor check and see what one has stocked in the refrigerator. And recently, a system enabling someone tomonitor the opening and closing of a refrigerator
from a remote location and monitor the activities ofsomeone who is home (say an elderly relative who is
becoming less independent) has attracted considerable interest.
In addition to these schemes for connecting terminals and equipment, another area of great interest is
network control in which a device is connected to the
network. For example, consider sensors. Considerable progress has already been made in developing a
range of sensor-based services for pinpointing position, surveillance, monitoring, and so on using acceleration sensor chips intended for installation in communication terminals, sensor nodes connecting various kinds of sensors to networks, and sensor-based
networks using these sensors.
Turning to the area of IC (integrated circuit) tags,
we have seen an enormous expansion of novel service linkages by connecting tag readers to the network. This offers an easy way to attach information
to objects, enabling IC tags to be used to trace foodproducts, for example.
1.3 Technology development issues
In an environment where all sorts of devices are
networked in the home, the workplace, and otherplaces, the question of how these devices are interconnected is a matter of great concern. Currently,
standardization of these networking issues—including the interconnectivity of home networks—is being
defined by several different standards-making bodies.
Standards generally deal with two kinds of objects:
layered models of protocols and the devices coveredby a standard. The layered models address framework
differences including applications (ensuring interconnectivity), protocols and middleware (data format, data exchanges protocols, etc.), and physical35

Special Feature

properties (physical media, signal schemes, etc.). The
devices covered by the standard include informationcommunication systems (personal computers, telephones, fax machines, etc.), AV components (TVs,
HDD players, audio equipment), and white goods
and environmental systems (refrigerators, air conditioners, sensors, etc.).
Many standards organizations are already involvedin this work, but although some progress has been
made in specifying interconnectivity between
devices, the standardization of the layered model isstill a long way off (Fig. 1). Nevertheless, since thedevices and layered model are closely interrelated,some resolution is urgently required.
As services become more diversified and home networks and appliances become more complex, issuesof how these devices can be made easy to master andhow advanced services can be easily provided are
critical in terms of development.
2. Efforts to date
Next, let us consider the NTT R&D initiatives todate in light of the above background.

2.1 Accommodating diversified equipment anddevicesA fundamental approach that will accommodate theproliferation of more diversified equipment anddevices is to base home networks on the concept of anopen service platform. This is essentially a system inwhich various kinds of program modules can be
deployed on the open service platform and equipment
and devices connected to the network can download
the program modules that they require. This approacheffectively prolongs the life cycle and extends thefunctionality of the equipment and devices.
Efforts have been focused on the development of
the Open Service Gateway Initiative (OSGi) with primary emphasis on refinement and application development. The OSGi Alliance was established in 1999
to draft and promote open service platform specifications. It currently has 40 members. On the domestic
front, the OSGi User Forum Japan was established topromote more widespread use of the standard fromthe user side. Through R&D efforts, it is helping disseminate the standard while cooperating in standardization activities.
The standard developed by the OSGi Alliance iscalled the OSGi Service Platform. The specification

Equipment
Information-communications systems

AV systems

White goods and environmental systems

DigitalHome-network
Forum

Application
DLNA

UOPF

Layers

HAVi
Protocol,middleware

UPnP
Bluetooth
ECHONET

1394TA

Physical

Wi-Fi

HomePNA

HomePlug

Fig. 1. Positions of standards organizations.

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Special Featuredefines that the service platform shall be installed ona Java virtual machine (JVM) implemented on hardware and operating systems, and various distributed
program modules can be either added or deleted as
required by Java while the system operates as normal(Fig. 2). The framework of this platform is implemented in such a way that basic functions needed forthe system, functions dealing with security and similar services, and basic functions required for network
connectivity are already standardized in the form of“standard functions” or “recommended services”.
New services can then be added or the overall framework can be extended or modified by adding or deleting service program modules. In the context of OSGi,
these program modules are referred to as bundles.
2.2 Improving equipment quality and operability
In the past, the emphasis on improving the quality
and operability of equipment has tended to focus on
the distribution of video and music. Video distribution is based on the assumption that faster optical networks will be implemented in the future, so systems
that will support high-speed streaming distribution up
to and including HDTV video signals are being considered. HDTV is carried by 25-Mbit/s IP packets, so
efforts are focused on supporting that throughput
without any loss of data. At the same time, progress

is being made on the interconnectivity standard
HSAC-RTSP that has emerged as a de facto serverclient distribution protocol for implementing video
distribution services (HSAC: Hikari Service Architecture Consortium, RTSP: realtime streaming protocol).
Meanwhile, with the goal of implementing userfriendly services for distributing music, good
progress is being made in operability for consumer
electronic, light processing load browsers, menudescriptive language configurations, and so on.
3. Future initiatives
As we are seeing increasing activity based on theassumption of ubiquitous information networks, asurvey was conducted to ascertain the misgivings andconcerns of ordinary people in using ubiquitous services. People were apprehensive about security andsafeguarding their individual privacy. Moreover,many respondents expressed apprehension about
increasingly complicated system operation. Since allkinds of equipment will be connected to the network
in future to implement an environment that seamlessly integrates this equipment and provides services,the problems of security and operability will certainly increase as time goes on. Here, I consider some

Framework using Java for adding/deleting distributed programs called bundles
while the system continues to operate

Permission admin

Package admin•••

Start level

System bundle(defined by OSGi specifications)

Service tracker

Device accessPreference service

User admin

Configuration admin

Log service

HTTP service

Basic service bundle(defined by OSGi specifications)

Position

UPnP device•••

Recommended
services(defined by
OSGi specifications)

Jini driver

Service 2

Service 1

BundleUser services(added by
downloading)

OSGi service platform
Java virtual machine
Operating system
HardwareFig. 2. OSGi service platform.

Vol. 3 No. 6 June 200537

Special Featuretechnologies that will be developed in this area in theyears ahead.

these capabilities is a service aggregation platformthat further extends the functional capabilities of
OSGi (Fig. 3). The scheme would manage bundles(program modules) on the server side, deliver bundles to home service gateways (the functional unit)
deployed in homes and offices, and support advanced
services through seamless integration of various
kinds of devices. The most unconventional andunique aspect of the scheme is that multiple service
providers would use the same device installed in thehome. This would permit more effective utilization ofdevice and would not only hold down the costs forseparate services but would also help stem the floodof new equipment and devices since it relies on a single gateway device.
Moreover, security issues relating to the use of bundles have emerged as a paramount concern. The
major issues are authenticating the interconnection
between server and client to ensure that the source ofthe bundle is a legitimate server and verifying thedownloaded bundles to ensure they are legitimate.
One scheme that has been proposed to address thesesecurity concerns is Communication Service
Concierge (CSC) [1], which would extend the security functions of the OSGi service platform by verifying interconnections between servers and clients,
providing encryption, verifying bundles, and controlling access during execution.

3.1 R&D approach to home networks
OSGi will further evolve into an adaptive middleware platform promoting the use of technologies thatwill provide (1) advanced services by integrating
devices, (2) effective utilization of resources, and (3)safe and secure services. More specifically, all sorts
of diverse services will be achieved by combining
devices for aggregate communications and information; e-commerce, settlement, and reservations;remote management and control; home security;
home control; and entertainment.
Consider home security as one example. By combining different sensor and communications devices,
we could develop a service in which a sensor detects
a problem or abnormality and reports it. There is
expected to be considerable demand for just such a
service in the future. In particular, services that alleviate the problems of the aging society are expectedin the field of home security. In addition, services corresponding to the conservation of energy and environmental problems that eliminate unnecessary
power consumption in the house are expected in thefield of home control, and they will play key roles insociety.
One concept being proposed that would support

If multiple service providers can share a “service aggregation function”, the costs for each service can be
reduced and the increase in gateway equipment can be stemmed.

Access from the outside

Home automation
Remote detection

Service provider

Maintenancespot checkEntertainment

Home security

Home service
operation system

Home service
gatewayService aggregation function

Fig. 3. Service aggregation.

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3.2 R&D approach to networked appliances
Turning to networked appliances, the primary issue
is how they can be made easier to use. Developmentof a user-friendly interface technology that eliminatesbarriers to easy operation is critical. Here, I will highlight three aspects of the issue: (1) Secure intuitive
operability, (2) operation support and proxy operation, and (3) diverse display, notification, and operability.
(1) Secure intuitive operability
IC tags have attracted considerable interest as a wayof implementing more intuitive easy-to-understandinterfaces. For instance, a system that connects an IC
tag with the network, reads it with a terminal, andachieves easy access to necessary information has
been examined. In such an operation, the IC tag will
specify the connection to the service and access to various types of information will be achieved easily. Workis now underway on a scheme that will extend this concept so that various networked appliances can use it.
The key issues are how to implement a trigger forusing services that is easy to use and how to develop aworry-free scheme that eliminates the potential problems of unwanted services imposing on you or yourservices imposing on others who do not want them.
(2) Operation support and proxy operation
It should be possible for a remote support center to
instruct someone such as a novice or an elderly person who is having trouble and for a designated alternate person to operate a terminal remotely for someone who cannot operate it by himself or herself suchas a grandchild operating it for a grandparent. Somework has been done in this area already such as thedevelopment of the remote desktop, but we need anew operating support scheme that supports interoperability between different hardware environments.
(3) Diverse display, notification, and operability
In a ubiquitous information environment, different
types of terminals and networks are often used in different locations. This requires technology that brings
together peoples’ activities and environments so thatthey are free to receive services from whatever equipment is available at a particular location with theassurance that it will work properly. In other words,
what is needed is a multimodal interface that effectively absorbs the differences between people, services, and equipment. For example, one solution
would be a system that takes the same basic content
and adapts it to whatever equipment is available
locally so the content can be delivered as video or still
images if imaging capabilities are available, as
speech if audio capabilities are available, or as email
Vol. 3 No. 6 June 2005

if only email capabilities are available in the environment.
4. Overview of the R&D Forum demonstrations
This section briefly describes the demonstrations
given at the Forum.
4.1 Home network demonstration
A service linking a number of devices was demonstrated under the title “Safety Home Demo” (Fig. 4).
A home service gateway unit was installed in John’shome along with various kinds of network-connected
device such as power meters, lighting equipment,
temperature sensors, displays, telephones, and motordriven curtains. In one scene, a visitor came to thefront door and pressed the intercom button. John
failed to notice because the buzzer was drowned out
by the TV. The home service gateway realized thatsomeone was pressing the intercom button and usedvarious resources to determine John’s location in thehouse. Once the system determined that he waswatching TV in the living room, it superimposed a
picture of the visitor in one corner of the TV screen.
The system could also have been set to automaticallylower the volume on the TV at the same time.
Temperature sensors let the home service gateway
recognize when a fire broke out in the house andsound a warning over the networked TV set (or telephone) via a notification service. Another service,linking a light sensitive sensor and a device for opening and closing curtains, automatically opened thecurtains when it was light outside and closed themwhen it was dark.
These and many other services will be made possible by introducing the service aggregation platform
technology now under development. While the system is up and running, it can accept additional
devices, devices can be combined to make new services, and required bundles can be downloaded fromthe server as needed.
4.2 Appliance demonstration(1) Broadband appliances
A number of advanced capabilities were demonstrated including simple operation, operation by
proxy, and remote operation (Fig. 5). A personal terminal was shown being used as a remote controller
for several different devices in the house, as an information terminal outside the office and on a businesstrip, and as a remote controller for taking over control
of another terminal in a remote location where an
39Special Feature

Overview of safety home demoIntercom image superimposed on TV

Detected fire reported to TV and phone

Curtains opened/closed and lights
controlled based on temperatureand light sensors

Power
meter
Lighting
Temperature, light, humidity sensors
Curtain

Telephone

Temperature,light,
humidity
sensors

Heat source
CameraIntercom

Required bundle is downloaded.
TV
BundleCommunications
network

BundleFig. 4. Demonstration at the Forum (1).
Overview of broadband appliances and refrigerator board demonstrations

RF-ID
Broadband appliances• Service accessed, information
shared by RF-ID• Remote operation using a mobile
terminal with remote controller capability

AccessInformation
SharedControl
Adapted display mode
Refrigerator board• Shared information forfamily using email• Display mode tailored to display device

Communications
network

Email

RF-ID: radio frequency identification

Fig. 5. Demonstration at the Forum (2).

elderly person was experiencing trouble. In otherwords, the system permitted a full range of operations
on the terminal in front of the user or on a remote terminal on a network.
(2) Refrigerator board
Since many families stick messages, memos, and40schedules up on their refrigerators as a convenient
central spot for sharing common family information,a digital memo (refrigerator board) could be just as
effective, but it must be implemented in such a waythat the same information can be shared on a numberof different devices with different display characterNTT Technical Review

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istics. In the demonstration at the forum, a multimodal interface permitted John to access the refrigerator board from a cell phone outside the house andfrom a PC or personal terminal inside the house. The
system automatically converted the format and content of the same message to match the display capabilities of the various networked devices.
Reference[1]

http://www.ntt.co.jp/news/news02e/0202/020227.html

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Profile■ Career highlights
He received the B.E. and M.E. degrees in electricaland electronics engineering from Kobe University,
Kobe, Hyogo in 1982 and 1984, respectively. He
received the D.E. degree in electrical engineering fromthe University of Tokyo, Tokyo in 1996. In 1984, hejoined the Electrical Communication Laboratories,
Nippon Telegraph and Telephone Public Corporation(now NTT), Kanagawa, Japan, where he has been
engaged in R&D of still image and video coding,
video communication systems, networked appliances.
He is now a Senior Research Engineer, Planning section at NTT Cyber Space Laboratories. He is a member of the Institute of Electronics, Information andCommunication Engineers of Japan, the Institute of
Image Information and Television Engineers, and theInstitute of Image Electronics Engineers of Japan.

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