A new architecture for cyber maps: An internet-oriented next-generation spatial information service System
Shigeru Shimada and Masaaki Tanizaki
Hitachi, Ltd,. Central Research Laboratory 1-280, Higashi-koigakubo
Kokubunji-city, Tokyo 185 Japan
EMail: {shimada,tanizaki] @crl.hitachi.co.jp
Abstract
To handle new information service environments, such as mobile or interoperable information
infrastructures, we propose an architecture for a next-generation spatial information service
system (NSIS). This provides vector-based spatial information using VRML, which enables
vector-based interoperable communications, unified management of spatial and attribute
databases by an ORDBMS, which brings effective management of multimedia databases, and an
active retrieval mechanism by connecting the ORDBMS with WWW servers to match the
distribution of spatial information with the capabilities of web clients. A prototype
implementation, called Cyber Map, demonstrates promising performance at retrieving spatial
information service via the Intemet.
Introduction
Communication infrastructures have made rapid progress recently, as illustrated by digital
communication networks using ATM, and wireless communication using PHS or satellites. And
using these communication infrastructures, Intemet-oriented communication techniques, such as
Java and VRML (Virtual Reality Modeling Language), are also being developed very quickly.
Through the integration of these sophisticated techniques, new information service systems that
use mobile or interoperable communications are reaching the stage of practical use.
In Japan, utility companies, such as electricity, telephone, and gas companies, who are advanced
users of geographic information systems (GIS), are strongly demanding a next-generation
system. This should be able to handle spatial information, which means not only two-dimensional
geographical data represented by maps, but also height information such as the
number of floors in a building or the depth of cables in a facility. Such a next-generation spatial
information service system (NSIS for short) will also be essential for the maintenance of city
information infrastructures, which became an important issue after the great Hanshin earthquake.
Many cyberspace plans have been announced by local governments in line with the new
information highway policy of Japan. This policy needs a new information processing style in
which all information is processed under intemetiintranet communication environments.
For this purpose, we are investigating a new system architecture for a system providing spatial
information services suitable for business needs rather than a simple map browser. As the first
step, in this study we propose a mobile and interoperable system architecture for an NSIS under
intemet and intranet communication environments.
Fig. 1. System concept of NSIS: Next Generation Spatial Information Service System
New Functions of NSIS
Our concept of NSIS is shown in Fig. 1. An intemet-oriented information service environment
will enable ~trieval from multiple databases at different WWW sites. For example, it will be
possible to display in real time a mixture of results independently retrieved from a database of
geographical maps (at site B) and from a database of underground construction (at site C). Trying
to meet these demand by conventional methods would involve heavy data conversion, making
the service impractical. Moreover, if wireless communication by PHS or satellite is supported,
then retrieval from mobile communication terminals will also be possible. Web terminal such as
Personal Digital Assistants (PDAs) will be able to retrieve data from geographical map/drawing
databases via WWW servers. This will make possible a mobile information service system,
which will be very effective for routine checking during normal operations or for recovery from
emergencies.
Problems in provinding these new functions
Many kinds of intemet-oriented information service systems have already been proposed and
they have passed through three generations of development, as shown in Table 1.[Kub 95][Mot
95][Sjn 94] For example, UCSB supports ADL (Alexandria Digital Library)[Alx 94], which can
provide worldwide geographical maps on demand, and Fujitsu supports “Wild Bird” [Wld 96],
which can provide mobile users in Japan with residential maps of urban areas. But almost all of
these information services have become stuck at the fmt or second generation, because of the
many problems, which are described below.
