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The term "push technology" has its roots firmly planted in the soil of the mainstays of information and news delivery: television, radio, newspapers, mail, periodicals, billboards, speeches. More recently, push technology has come to mean information delivered to you electronically (mainly, email). In the early 90s, services were introduced (for instance, Desktop Data) that delivered highly customized information (such as stock prices) to a limited number of people. Within the last year, however, push technology has taken on a new face: it now includes webcasting, a client to intermediate-server to server technology that provides subscription, publication, and innovative desktop delivery of news and information. What are Webcasters and Who Are the Key Players? In March 1996, the first webcaster, PointCast, appeared on the market (see Figure 1). Over twenty more webcasters came out later in the year. Industry forecasters predict that this year the market will swell to more than thirty entries, but will then go down to about six. Indeed, IFusion's ArrIve was taken off the market this March.
Figure 1: Timeline tracing webcasters and what MITRE has done with them. To simplify the chaotic webcaster marketplace, we have divided it into four parts:
What Are the Webcasting Standards? Although the webcasting marketplace is young, there is already an outcry for standards. The first attempt at a webcasting standard is Microsoft's Channel Definition Format (CDF), introduced this March. Microsoft's CDF is an open specification that defines specialized Extensible Markup Language (XML) tags to supply meta-data that gives webcasters title, author, logo, category, rating, schedule, and other valuable information about a channel. What is MITRE Doing with Webcasters? With the emergence of PointCast in March of 1996, the MITRE Technology Program was interested in finding how webcasters could be used for our sponsors. MITRE created two separate research projects to (1) find practical applications for emerging information technologies, and (2) make global broadcast technologies more efficient and effective. This research has yielded two prototypes for using webcasting technology: the MITRE Broadcast Network (MBN) and the Common Datacasting Architecture (CDA). MBN Prototype MITRE developed the MBN prototype to explore the use of push technology for a MITRE intranet channel. MBN uses the PointCast I-Server and client to deliver news and information to MITRE staff. MBN uses a manual publishing scheme. The publishing interface is a web page, pictured on the left side of Figure 2. Once the article is submitted via the web page, and the PointCast client performs an update, the article will appear under the designated topics within the MITRE channel (shown on the right side of Figure 2).
Figure 2: MBN submission page and PointCast client with MITRE channel.
CDA Prototype Being able to generate articles automatically using agents connected to continuously updated information sources (as demonstrated by the MBN work) was recognized as a valuable mechanism for receiving information in an intranet environment. The CDA team sought to take the lessons learned from the MBN prototype and develop a more general architecture for information channel subscription, publication, and dissemination (see Figure 3).
Figure 3: Objective CDA with examples of components planned for integration. The Objective CDA breaks the information world into six distinct components. On one end of the architecture are information providers, and on the other end are consumers. Webcasting products are the channel transmitters (servers), repeaters (intermediate servers), and tuners (clients), which handle packaging, delivery, notification, and display of the information. An extensive search of the marketplace found little standardization either among the information providers and their agents, or among the host of channel transmitters. Since we needed to bridge the gap between information providers and channel transmitters, we created the Channel Builder component. The Channel Builder creates subject-based channels of information, connects those channels to both manual and continuous data sources, and transmits that information through various channel transmitters. The initial CDA prototype is up and running within the MITRE intranet. It continuously serves subject-based information to the MBN and a local Backweb server. What is MITRE Doing for Sponsors? During 1997, MITRE demonstrated the MBN and CDA prototypes to its sponsors. These demos have sparked interest in the communications and information management communities. Specifically, we are involved with setting up pilot test capabilities for the Electronic Systems Center MILSATCOM and Joint Global Broadcasting System (GBS) Program Offices as well as COSPO (Community Open Source Information Service), DARPA (Defense Advanced Research Project Agency), and FBIS (Foreign Broadcast Information Service) GBS/CDA Integration Pilot Test Part of the research funds that went into the development of the CDA also went into the examination of the GBS testbed system and the Joint Broadcast Service system in operation in Bosnia. The enhancement most requested by the users in the field is a mechanism to redistribute information from the GBS receiver site to the warfighters in the theater of operations. "The information does me no good at the receiver, I need it on my workstation," is a popular refrain. The second major issue is how to ensure that the new high-bandwidth satellite channels are used efficiently, by keeping them continuously filled with information of value to the warfighter.
In an effort to demonstrate a candidate solution to each of these issues, the CDA project team is working to integrate both the current GBS testbed transmit and receive stations with the Channel Builder prototype (see Figure 3). BNN/CDA Integration Pilot Test BNN is a web-based News Navigator created by MITRE (see "Personal Broadcast News from BNN" by Andrew Merlino and Daryl Morey). To tap into this valuable information source and supplement the web-based interface with a webcasting one, we are planning to integrate the BNN with the CDA. An initial prototype of this capability is now operational within the MITRE intranet. There are plans to provide a pilot capability for members of COSPO, DARPA, and FBIS in July 1997. For more information, please contact Michael Hebert using the employee directory. |
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