Letters

A Study on the Formation ofCommunities Using Broadband Networks
Norio Tamaki†, Ryuji Miwa, Hiroshi Watanabe, andNobuhide Nishiyama
Abstract
The diffusion of optical-fiber networks in recent years has made it easy to provide broadband capability, thereby holding out the possibility of transforming the business sector and society at large.
Because broadband networks support video and voice as means of communication, people are able tocommunicate even if their capabilities for information input and output are low. This article surveys customer networks and related technological trends in relation to the addition of functions supporting theformation of communities, so as to enable local communities to make effective use of broadband networks.

1. Trends in Community Networks
The term community network is used in a variety ofways: some typical examples are discussed here.
Community networks are being examined at the local
level, separate from commercial networks that use
the Internet, e-mail, or some other technology as ameans of communication. Linking these local community networks to global networks enables users tocommunicate with other people throughout theworld. Such networks are referred to as community
area networks (CANs), and the people who use them
are called netizens.
Community networks are also being discussed in
the context of e-democracy, which has been defined
as representing the next generation of electronic government. This is indicative of the impact of the information technology (IT) revolution on everything,
beginning with the economy and extending to government systems, political systems, medicine, social
welfare, education, and communities, and its potential for radically transforming conventional personaland organizational relationships [1]-[4]. It is projected that the effects of the IT revolution will probably

spread though all social systems in general in the next
twenty years or so.
There have also been reports of various examplesof community networks that are being considered asa means of countering the unilateral concentration of
population in large cities Such networks are being
examined with the aim of correcting regional disparities and revitalizing local communities, among otherobjectives. Moves are also being made toward theformation of new communities, including the construction of local CANs centered on schools.
Meanwhile, there are reports of communities being
formed as a result of people congregating in certain
particular places, notably condominium complexes[5]. Such communities are useful for enhancing theconvenience of condominium residents with respect
to security, disaster prevention, building repairs, andso on, and they improve the daily lives of people
within their own respective areas. Priority is put on
resolving issues of mutual concern to communitymembers. As indicated here, community-based information systems are strongly expected to serve as
next-generation networks.
2. Nascent New Communities† NTT Access Network Service Systems Laboratories
Tsukuba-shi, 305-0805 Japan
E-mail: n_tamaki@ansl.ntt.co.jp

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There are signs that new communities are needed inplace of traditional physical ones, in conjunction withNTT Technical Review

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the aging of the population and advances in telecommunications.
(1) Fulfillment of communication needs
For retirees, communication with other people
makes their lives much more worthwhile. There aredemands for means and methods that facilitate evenmore seamless and simpler communication.
(2) Revival of community awareness by enhancing
communication
Advances in telecommunications have brought
about new modes of work, including working athome, and it is likely that more people will have closer ties to their local community in future. Even now,there are people who feel something is lacking in
weakened human relations and desire new forms ofcommunity.
(3) Renewed awareness of communities as communal societies
In newly developed urban areas populated by a
mixture of various sorts of people, there is a budding
consciousness of the need to protect children, alongwith a renewed awareness of the need to have a community network as an emergency system for dealing
with earthquakes and other disasters.
On the other hand, also important to the formationof society are ties consciously selected by people
having similar interests stemming from their physicalassociation with and connection to the local community. Accordingly, while the importance of the local
community may be declining owing to the formationof networked communities, the value of the local
community is once again being recognized.
3. Broadband Community Overview
Figure 1 illustrates the construction of a networkthat embodies functions for forming the communitiesmentioned above. Unlike traditional networks, it isenvisioned here that a network is constructed as anamalgamation of several community networks. Individual users are conscious of building their own networks, and the community can determine what functions are necessary. Because networks are delineatedon the basis of individual areas, they can incorporatea myriad of functions depending on the will of thecommunity members, instead of being uniform as
they were in the past.
For instance, installing optical fiber in a condominium complex achieves a sophisticated, highspeed communications environment. Various specificways of constructing such a network are conceivable,
such as by asking a telecommunications carrier tobuild it or by utilizing the carrier’s service menu.
Community networks may take many diverse forms
and several possibilities are conceivable for theirscale. Here, we consider each network being constructed in a star-shaped configuration with external

Fig. 1. Construction of a community network by linking small-scale networks.

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79LettersFig. 2. Architecture of area community network.

connections made by means of Local Intelligence(LI)*1. A generic representation of the architecture isshown in Fig. 2. It is considered that LI embodies thefunctions needed to form communities.
By adopting a hierarchical structure within communities, it is also possible to construct them of subnetworks. For example, a home network is regarded
as being one sub-network, and a condominium network is presumed to constitute a community network.
Schools, offices, and other places also form similarcommunities. Additionally, an administrative division can be viewed as constituting an area community network as a result of combining a number of condominium networks. By constructing a community
network with this type of hierarchical structure, it ispossible to gather information from outside the area
in response to a variety of needs and to provide information everywhere within the area in accordancewith the desires of the area’s residents, as outlined inFig. 3.
*1 Local Intelligence (LI) is defined as server functions that support
information exchanges and network maintenance and management, among other capabilities.

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4. Study on the Formation of Broadband
Communities
It is assumed that a broadband community can berepresented with a three-layered model, as illustrated
in Fig. 4.
Lower layer construction
The lower layer provides the network, which can beconstructed of metallic cable, wireless links, opticalfiber, or other technologies. A wireless or metallic
cable network is simple to build, but there are limitations on the transmission distance and speed. Considering its properties, optical fiber [5] is recommended
for forming communities.
Middle layer construction
The function of the middle layer is to promote thesharing of information between communities.
Because communities are formed independently of
one another, a function for enhancing the communication of information is necessary. A common framework must be built that enables communities to discover and utilize each other’s resources, while at theNTT Technical Review

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Fig. 3. Conceptual image of area-centered community formation function.

Fig. 4. Three- layered model of broadband community.

same time making effective use of their existing systems (protocols). In addition, this layer also incorporates a function that facilitates external managementof network utilization via a centralized interface.
In this way, multiple communities (user networks)
can complement each other’s resources and combine
their capabilities, enabling economical provision ofsophisticated communications services. The facilities
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of communities are thus interconnected to achieve anenvironment that functions as the communications
infrastructure.
Upper layer construction
The upper-layer functions for community formation are considered in terms of two aspects, namely,
functions supporting the transmission of information
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within and outside the community and operation-freefunctions supporting the reception of information.
Functions supporting information transmission
Support functions enabling individuals to transmitinformation within and outside the community must,of course, be simple to operate. They must also
ensure anonymity and proper transmission of information so that individual recipients are not inconvenienced. One means of achieving such capabilities isa function for managing the community profile. Thisfunction would automatically generate and update theoverall community profile in real time, based on
information concerning the attributes of the recipients making up the community, such as their age andgender. A function is also needed for designating theattribute conditions and the sender’s form of transmission (e.g., transmission of the actual data or notification of an alias only, transmission scheduling,etc.) and also for categorizing and revealing only thetype of community to which the sender belongs,instead of attaching the sender’s personal data to theFig. 5. Overview of functions supporting reception of information.

Fig. 6. Screenshot of area community system.

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information that is transmitted. Furthermore, a function is needed for designating on the sender’s side thetype of information to be transmitted (e.g., text only,voice only, video and voice, etc.). It is envisioned thata concierge function will be provided to support asystem that incorporates these capabilities and transmits and distributes to the community at large theintended information in cases where the sender isauthenticated and the attribute conditions match.
Functions supporting information reception
Community members should be able to automatically receive essential information within their community, including information of local interest,
regardless of their knowledge of the network. Automatic reception of emergency information in theevent of a disaster is also necessary. Moreover, in asmuch as a community comprises a mixture of users
with diverse attributes, all members should be able toenjoy the benefits of receiving information precisely
tailored to their individual attributes and preferences.
A user profile management function is seen as beinga means to achieve these capabilities. With this function, all members would register their attribute datawith the community in advance; they would filter theinformation that circulates within the community andreceive only the information that they need. A network concierge function is further envisioned thatwould serve as an agent in providing the optimum
information to recipients.
Support for forming communities
We are now working on the development of an area
community system that embodies the above-mentioned functions and is intended to support the formation of communities. An overview of the functions
supporting the reception of information is given inFig. 5, and a screenshot of the system is shown in Fig. 6.
As indicated here, the system can provide a highly
secure communications environment with high functionality even when displaying video images.
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2001.
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[3] T, Saito, M. Hase, M. Hatanaka, and N.
Sonehara, “HIKARI Commerce Service.” NTT
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REVIEW Vol. 13, No. 4, pp. 14-19, 2001.
[4] T. Fuchigami, N. Tamaki, M. Hase, and H.
Kuwano “HIKARI Community and Collaboration Service,” NTT REVIEW, Vol. 13, No. 4,
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REVIEW, Vol. 15, No. 2, pp. 27-31, 2003.
Norio Tamaki
Group Leader, Customer Systems Project,
NTT Access Network Service Systems Laboratories.
He received the B.E. and M.E. degrees from
Keio University, in 1977 and 1979, respectively.
In 1979, he joined the Electrical Communication Laboratories, Nippon Telegraph and Telephone Public Corporation (presently NTT),
Yokosuka, Japan, where he was engaged inresearch and development of PCM transmission
system, trunk transmission systems, leased line
equipment and optical access network systems.

Ryuji Miwa
Research Engineer, Customer Systems Project,
NTT Access Network Service Systems Laboratories.
In 1980, he joined the Equipment planningdepartment, Nippon Telegraph and Telephone
Public Corporation (presently NTT), Shizuoka,Japan, where he was engaged in Equipment planning.

Hiroshi Watanabe
Research Engineer, Customer Systems Project,NTT Access Network Service Systems Laboratories.
He received the B.E. and M.E. degrees from
Tokyo University, in 1996 and 1998, respectively.
In 1998, he joined the NTT Access Network
Service Systems Laboratories, where he has been
engaged in research and development of customer network systems.

Nobuhide Nishiyama
Research Engineer, Customer Systems Project,
NTT Access Network Service Systems Laboratories.
He received the B.E. and M.E. degrees from
Kyoto University, in 1997 and 1999, respectively.
In 1999, he joined the NTT Access Network
Service Systems Laboratories, where he has been
engaged in research and development of customer network systems.

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