Keith Schall
US Army Training Support Center

When the Army converted to digital technology in 1990, its Teletraining Network (TNET) was the first in the world to use two-way compressed digital signals over satellite links primarily for training purposes. The technology was very young and its application brand new. In those days "distance learning" meant correspondence courses, teletraining was still a novelty, and the Army wasn't ready to commit to anything larger than a proof-of-principle effort broadcasting a digital signal: one course to National Guard soldiers at five sites in Kentucky.

That teletraining pilot has since matured into the mainstay of the Training and Doctrine Command's (TRADOC's) Distance Learning Program. TNET has grown to 62 sites, broadcasting more than 35,000 hours of training over ten satellite channels nearly around the clock. It has joined with the Army's Satellite Education Network that reaches 102 sites using one-way video, two-way audio. Through links at SEN, Iowa, Vermont, the Air Force Reserve's TNET, the Navy's Electronic Scholhouse Network, and Department of Defense (DOD)Video Teleconferencing, it can reach more than 1200 sites in the continental United States, as well as overseas sites in Kunia, Hawaii; South Camp, Egypt; and the Bosnia area of operations. Units in Puerto Rico, Korea, and Panama are interested in joining the network.

Higher education augments military training on TNET. To provide college courses to soldiers in South Camp, the City College of Chicago has installed a T- 1 line into TNET. Old Dominion University, Virginia, is installing one to connect its Teletechnet, the University of Maryland is installing an integrated services digital network (ISDN) link, and Embry-Riddle Aeronautical University is offering specialized courses from TNET to sites around the country. The University of Virginia has contacted TNET about establishing an interlink.

These links create an advantage for soldiers enrolled in specialized college courses. When local enrollment is too low to permit the college to offer a particular course locally, a teletraining version can attract enough students nationally. Soldiers will be able to continue their degree programs without interruption.

Teletraining's growth has not always been smooth, but this quick review of events during the last five years reveals how Army teletraining has encouraged change and sets the stage for the advent of TRADOC's Army Distance Learning Program and the new TNET contract, the projected award date for which is November 1996. The Distance Learning Program, which owes much of its impetus to the success of video teletraining, is scheduled for implementation and operation over the next 13 years. The new TNET contract will provide advances in connectivity, compression technology, optional capabilities for specialized purposes, and network operations.

The new TNET contract tries to coalesce some of the changes in connectivity that have already occurred but make them even easier, more transparent, and more flexible than they are now. It does so by specifying teleport, or gateway, services for more elegant, user friendly, reliable connectivity. At present TNET established connectivity by installing equipment suited to serve as gateways or by using the links at Forts Lee and Knox to get into the DOD Video Teleconferencing Network. Teleport capabilities should increase the number of nodes for establishing connectivity and reduce the amount of telephone coordination now necessary and the number of people involved in the scheduling process. A teleport should permit multiple bridged conferences simultaneously. It should also establish connectivity to ISDN, Internet, and potentially other new communication modes such as the asynchronous transfer mode (ATM) that weren't available only five years ago. Expanded communications should allow the integration of desktop video into the network, relatively simple connectivity into state networks, and the most cost-effective communications technology as new networks arc established, existing networks expand, and changes to the national infrastructure determine whether satellite or terrestrial communications are the most efficient.

Depending on the plan for teleport connectivity submitted by the winning contractor, the gateway, or one of the gateways, could be located at TNET's Network Control Center (NCC) at Fort Eustis, Virginia. Such an arrangement would ensure a very responsive, reliable capability, overwatched by the program manager and particularly by technicians whenever a training conference is in session. The teleport will have to be able to connect technologically diverse equipment: satellite and terrestrial communications; one-way and two-way video; room size and desktop systems; equipment from different manufacturers; and federal, state, and private networks. In fact, the teleport capabilities could be so extensive as to complicate class management and pedagogy for trainers whose classes are "located" at technologically diverse sites. Imagine the complications, for instance, of handling interaction among 17 students at three sites with one-way video, 15 students at two sites with two-way video, and 23 students, one each at a desktop system. We can forewarn instructors to ensure interaction among all participants, we can even write interaction into the courseware, and we can anticipate the protocols instructors will need to administer training in such an environment. First hand experience will undoubtedly force us to reconsider our recommendations and revise our instructor training courses.

In the future much more than now, instructors will be teaching over several networks simultaneously. From the instructor's perspective the expanded span of coverage will cause problems in providing hard copy course materials, conducting real time testing, and ensuring that all students have fair and ample opportunities to display their work.

From the students' perspective the diverse technology will mean increased access to training. On the other hand, the technology each uses will restrict or expand learning opportunities and impact learning styles.

Video compression technology has improved remarkably over the last five years, and TNET has increased both the broadcast speed at which it operates from 256 to 384 kbps and the number of sites that can participate in a multipoint conference from 8 to 16. The new contract calls for an increase in the frame rate from 15 to 30 frames per second, which will improve the quality of the video even further. It also calls for increasing the number of sites able to participate in a multipoint conference from 16 to 48 or more. This increase in the number of participating sites will cause additional protocol problems for instructors especially in controlling audio participation. Imagine a telephone conference call among 48 people in which four or five always try to speak at the same time. The same kind of confusion can occur in teletraining unless the instructor establishes rules for participation: the larger the conference, the more stringent the rules.

In addition, recognizing that particular training applications might make do with slower transmission rates or require fast rates, the contract calls for a range of optional capabilities from 128 kilobits per second (kbps) to 3.3 megabits per second (mbps) and even analog transmissions. The standard data rate will continue to be 384 kbps, just as it is now, a rate the seems suitable for the large majority of training applications, especially considering that the video compression makes today's 384 look better than yesterday's video at twice the data rate. Slower data rates are necessary for desktop video conferencing, though we expect that technological advances will soon permit faster data rates for desktop systems. The high end data rates are intended for special applications such as medical training or electronics repair for which finer resolution is necessary. Costs for faster data rates will have to be borne by the users.

Linked to transmission rates are TNET's requirement for the instructor site to be able to control video at the student sites and the capability for automated scheduling of broadcasts. As the Distance Learning Program grows, the number of classes will increase, putting additional demand on sites as either uplinks or downlinks. TRADOC recognizes the potential for scheduling conflicts and the need to establish priorities for handling them.

The TNET contract offers optional capabilities to agencies with special training requirements. These include VCRs and multimedia computers, smaller TV monitors for classes of fewer than 10 students, projection TVs for classes of up to 100 students, room controls built into a podium for instructors who need to stand during their classes, and student response units. These latter systems, which are especially effective for large classes or classes being broadcast to a large number of sites, permit students to interact with the instructor through a hand-held keypad, take quizzes and tests electronically, express opinions and have them tallied at the instructor's location. Student response units can increase interaction while decreasing the competition for audio, but instructors need to rehearse with them, and courseware developers need to create courseware that makes effectual use of them.

Acquiring the latest, most advanced and effectual technology is relatively easy compared to managing the network, keeping it functional, and responding to users' requirements.

In today's TNET contract, the Network Control Center is the first line of response for maintenance. That plan has worked quite well, with contractor personnel and military specialists staffing the NCC. Over the years, network reliability has improved to nearly 100 percent, and the majority of trouble calls received over the hot line turn out to be operator induced errors that the technicians can diagnose and rectify within a few minutes.

The new TNET contract assumes a perfectly operational network and puts the responsibility for operational readiness on the contractor's shoulders. This change is a result of fully recognizing that the contract is a service contract and of DOD downsizing. It becomes harder and harder to staff the NCC with qualified noncommissioned officers (NCOs). Day-to-day scheduling and maintenance and specialized installations will become the contractor's responsibility. This in turn means additional record keeping at TNET and at the various TNET sites because oversight of the contract will be more complicated.

The new TNET contract calls for a site to be operational within 30 days after receipt of order, half the time available in the current contract. TNET is also planning to increase the number of deployable equipment suites ready to support special requirements, and the contract calls for an optional mobile capability. TNET expects to migrate from satellite to terrestrial communications. All of these changes will improve the network's flexibility, permitting it to respond to the needs of the Army and its other customers.