Five NII Service Areas

 

Returning to Web software architecture of Figure 1, we now discuss services and applications. These are not precisely defined, for services are essentially generic applications, and most applications are complex metaproblems [2] built recursively from services and ``sub-applications.'' Thus, there is a grey fuzzy line distinguishing services and applications.

• WebTop Services--Publishing, Productivity, Software Engineering

  Here, we put base productivity tools including ``WebWord,'' ``WebLotus123,'' Web linkage to relationship databases, etc. NPAC has built an interesting prototype of such a capability in Webfoil--a Web based presentation system. Essentially, all applications use this service.

• InfoVISiON--Information, Video, Imagery, Simulation, ON demand

  This includes base database storage, management, query, and dissemination of the full range of multimedia archives of the World's distributed digital libraries. We can expect the ``digital TV'' application to produce hundreds of Terabytes of available information dominated by video data. Note delivery of results of a simulation--such as access on demand to a weather model--is included in this service.

  In manufacturing, InfoVISiON corresponds to delivery of data in a configuration controlled database. In command and control, this service allows commander to index and access videos of battle damage videos or real-time engagements.

• Commerce--Digital Cash, Security, Authentication, etc.

  This collection of services enables electronic commerce, including on-line banking and shopping. These services are also essential for the use of the WWW for processing and exchange of proprietary (manufacturing), and classified (military) data.

• Collaboration--Real-Time Interactive and ``Batch''

  This includes desktop video conferencing, three-dimensional graphics MOOs, geographically distributed CAVEs leading to full televirtual interactions. The emerging VRML 2.0 standards will be very important in building virtual environments. As discussed earlier, a wide variety of other types of interactive information exchange is necessary. This underlies the concepts of collaboratories (virtual research groups or scientific laboratories), and the virtual company of the next century's agile manufacturing environment. In the more static mode, we see workflow and configuration control, which allows tightly integrated projects, such as those needed to build a complex system including an aircraft (see Section 4) or a large software module with a distributed team.

• Metacomputing--A worldwide collection of computers organized together as a single computational engine for simulation or information processing [3].

  This service can be used to control remote medical and scientific instruments; search the world for information; simulate the weather expected in a military engagement, or link computers in different companies for a multi-disciplinary optimization of a new vehicle.

Some services listed above can be already prototyped in terms of today's Web technologies. For example, base WebTop or early Collaboration services are now becoming available. Some other services are still waiting for their pervasive enabling technologies, such as physical infrastructure that will enable InfoVISiON or security that will enable Internet Commerce. Finally, the computationally extensive NII services, characterized above broadly as ``Metacomputing'' require a major extension of the whole Web paradigm, currently still focused on static page services, but already gradually expanding towards computation and interactive simulation via technologies such as Java and VRML.