By Sam Silverstein

Improvements in satellite communications technology during the past few years have been making it easier and less expensive for people at multiple locations to work and study collaboratively. Interactive satellite-based networks make it possible for people to receive job training regardless of their office location, learn from teachers in distant cities and provide medical care even if they cannot physically be with a patient.

Even as ground-based networks become more widely available, satellites remain the technology of choice for these kinds of services, known collectively as distance learning. The advent of highly efficient digital telecommunications techniques, coupled with the rapid build out of fiber-optic and other ground-based facilities even in less-populous areas, has spurred some users to reexamine their technological requirements–and pass over satellite systems whenever possible. And the spread of high-speed Internet connections has allowed people to use personal computers to enjoy many of the benefits afforded by traditional, satellite-based distance learning techniques.

But on the whole, satellites are holding their own in the distance learning industry because of their ability to link scattered locations without concern about what kind of terrestrial technology may be available, says Simon Bull, an analyst with Comsys Ltd., a satellite communications consulting firm based outside of London. "If you want to cover a lot of sites with a single transmission, then satellite is what you want," says Bull.

Rather than spur distance learning providers and users to abandon satellite technology in regions where ground-based systems are widely available, such as Western Europe and the United States, technological progress has instead inspired the development of new techniques to allow terrestrial and space-based equipment to work better together. In addition, new innovations have improved the reliability and cost-effectiveness of satellite systems in distance learning settings, according to industry officials.

Mike Stubblefield, distance learning technology product manager for Convergent Media Systems in Alpharetta, GA, says satellite technology’s inherent strengths mean it has an important place in distance learning. Satellites are prized for their ability to efficiently transmit content from one point to many locations and they provide security by allowing users to avoid ground-based networks that may be subject to intrusion, he says.

"Satellite networks are private," whereas a ground-based network can be susceptible to unwanted snooping, says Stubblefield, whose firm provides satellite and ground-based hardware and software for business television and other types of distance learning applications.

Stubblefield adds that digital technology enables satellites to be used to carry computer files as well as high-quality video to multiple locations at once using Internet protocol, adding to their utility in the educational and training arenas. The analog satellite technology, which came before today’s digital systems, required the use of an entire transponder to carry a single video feed and could not handle video and data together.

Ground-based systems can impose transmission delays, known as latency, depending on the amount of traffic traveling over a particular network, a potential drawback depending on the application, says Stubblefield. He says satellite networks are particularly good at avoiding these kinds of delays because they do not involve the use of shared bandwidth, as can occur with a terrestrial connection.

Still, terrestrial connections are attractive in many instances because they avoid some of the often-high costs associated with leasing satellite transponder capacity. In addition, not all distance learning applications depend on the ability to beam live, high-quality video, says Stubblefield.

The bottom line is that distance learning is being redefined as improvements in technology make advanced telecommunications ubiquitous and digital systems allow the combination of video and other kinds of data into a single chunk of bandwidth, regardless of whether it travels via satellite or on the ground.

"It’s all about connectivity," says Warren Brown, vice president of marketing at iDirect, a Herndon, VA-based company that designs systems to allow satellite and ground-based networks to work together. "Distance learning is just what you’re carrying across the network."

Sometimes distance learning companies perform basic roles for customers with relatively simple needs. For example, providers can offer users the ability to replace hand- delivered CD-ROMs with one-way data broadcasts, eliminating their reliance on often-slow mail services to obtain educational materials, says Diana Cantu, director of business development at International Datacasting Corp. (IDC).

Based in Ottawa, IDC sets up data-transmission systems for clients around the world, and provides a wide range of services for customers in underdeveloped regions such as Mexico, where the company set up a sophisticated network to support a virtual medical school. "Distance learning involves all kinds of scenarios," says Cantu. "It’s really important to listen to what the customer wants and needs."

Many players in the distance learning market have carved niches by focusing on particular capabilities that make the technology more transparent to users. One of those firms, KenCast Inc., provides systems that can compensate for rain fade, one of the limitations of satellite communications.

"You can’t always get enough power to burn through [very heavy] rain," with a satellite transmission, but KenCast has developed equipment that corrects the transmission errors that can result from atmospheric moisture–and potentially disrupt transmissions, says William Steele, the company’s founder, chairman and chief executive officer. KenCast’s so- called forward error-correcting technology allows a receiving system to repair a damaged file without having to communicate with the originating site, making it easier and less costly to distribute material via satellite.

Steele says his company, based in Stamford, CT, combines ground- and satellite-based systems for distance learning, building on each technology’s strengths to provide innovative services. For example, he says KenCast helped build a network in the United States that transmits training material via satellite to roof-based antennas that can relay it wirelessly to rescue personnel on the scene of an unfolding emergency. "It makes a tremendous library of information available to police and fire departments," says Steele.

Improving the way satellite and terrestrial communications technologies work together also involves making it simpler for users to select the resources they need and figure out what their desired set-up will cost. Among the firms that have worked to make distance learning arrangements easier is ScheduALL, a Hollywood, FL-based company that supplies facilities management software to clients including broadcasters and educational institutions.

Just as TV broadcasters ultimately are concerned with beaming a program from the point of origination to viewers, organizations involved with distance learning do not want to worry about the technology as they concentrate on allowing people at multiple locations to learn together, says ScheduALL’s president, Rick Legow.

"We simplify a complex process [that involves] managing schedules, inventory, people, equipment and transmission paths, and orchestrating everything so all elements work together at the same time," says Legow.

In addition to smoothing the process of arranging for satellite or terrestrial transmission capacity, or a combination of the two, ScheduALL’s software helps track the costs of setting up and running a distance learning network.

Despite the advantages of satellite systems, some distance learning users are gravitating toward ground-based technology, having found that they simply no longer need to use often-costly transponders in space for many of the activities that used to be impossible without satellite links.

Penn State Public Broadcasting, part of Pennsylvania State University in State College, PA, is an example of an educational institution that is slowly replacing satellite connections with ground-based solutions, says Duane Champion, director of computer technology for the organization.

"When we started doing distance learning 15 years ago, our system was satellite-based and used a telephone line" for a simple return link from remote sites to the location where courses originated, Champion says. But now, "the cost of satellite time has made things more expensive" even as ground-based technologies have improved and decline in cost, providing an incentive for Penn State to move to ground-based systems and depend more on the Internet to enable distance learning.

Champion says Penn State Public Broadcasting has started using datacasting technology to transmit material to students using terrestrial digital television broadcasts. The technique involves piggybacking educational transmissions on normal TV signals and allows people with a minimal amount of reception equipment to receive high-quality broadcasts of an instructor’s presentation without the hassle and expense of a satellite system or other specialized reception hardware. "Everyone can have a robust connection in their home or business" as long as they are within range of the necessary television signal, he says.

Champion adds that terrestrial technology offers another advantage: the ability to easily and inexpensively customize transmissions for a relatively small area. Terrestrial datacasting allows local public broadcasting stations to modify the material they receive from Penn State to reflect the specific needs of their service area, something that would necessitate multiple satellite transmissions and result in high transponder costs, he says.

Despite the challenge posed by terrestrial communications technology, proponents of satellite-based distance learning say orbiting transponders remain the best way to bring distance learning capabilities to many parts of the world, especially where ground-based networks are not as well-developed as they are in other places.

Stephane Germain, vice president of sales and marketing for EMS Technologies’ broadband division in Montreal, says satellite technology is an essential component of distance learning in many of the places where the ability to receive training and study remotely is most critical. As a key supplier of satellite networking equipment, EMS focuses on underdeveloped markets in Asia, Russia and elsewhere where satellite systems frequently are the only viable telecommunications option.

Germain says some of the best opportunities in distance learning lie in areas where terrestrial telecommunications capabilities are underdeveloped–and government officials are often eager to bring educational opportunities to underserved people.

Indeed, many countries are placing increasing emphasis on extending educational opportunities to people in remote regions where infrastructure is poor, making satellite systems as valuable today as they were when distance learning services first began appearing, Bull says.

After officials in China granted universities the right to offer degree programs using distance learning techniques several years ago, educators in that country were quick to embrace satellite-based systems to reach people in remote areas, says Michael Santos, vice president of strategic business development for ChinaCast Communications Holdings Co. Ltd., a satellite service provider in Beijing that specializes in educational services.

Distance learning is growing fast in China, and ChinaCast is currently providing broadband connections to 82,000 students from more than 10 Chinese universities using the company’s satellite network, Santos says. ChinaCast also supplies its services to government agencies, businesses, and primary and middle schools, he adds.

As satellite technology advances, companies involved in distance learning are finding ways to improve their services. Germain says EMS’s efforts in distance learning are built around the DVB RCS standard, a satellite transmission protocol that is growing in popularity around the world and helping bring down the cost of satellite equipment. "People are demanding more open standards," which bring operational simplicity and the assurance of multiple suppliers, he says.

Meanwhile, companies involved with distance learning are closely watching the development of the relatively new Ka-band satellite business with particular interest, because spacecraft that operate in this frequency band promise to reduce the cost of satellite bandwidth and user terminals. But with only a small percentage of the world’s commercial satellite capacity now in the Ka-band, it is likely to be a while before the band’s impact on applications such as distance learning becomes apparent, says Jack Waters, senior vice president of global sales for iDirect.

"Ka-band may make satellite networks more economical, but right now Ku-band equipment costs are coming down and are less than Ka," says Waters. Ku-band satellite transponders are widely available around the world and are frequently used for distance learning networks.

Bull agrees that the Ka-band holds the promise of making satellite connections more accessible and less costly for distance learning operators, but he emphasized that the band’s impact on distance learning has so far been minimal. "You have to recognize the limits of Ka-band. It’s not global right now," he says.

Moreover, some Ka-band satellite designs feature spot beams to make efficient two-way connections for services such as high-speed Internet possible, a capability that could prove to be a drawback in a distance learning setting, Bull says. This is because distance learning systems can benefit from the ability to broadcast material over a wide geographic area, yet it does not necessarily depend on the ability of users to have high-speed connections in order to interact with their instructor or other participants, he says.

Beyond allowing people to learn together even if they are located far apart, distance learning systems bring added convenience to people’s lives by allowing them to study whenever their schedules allow. With access to any sort of high-speed data system, users can download large amounts of data, including high-quality video and review it at their own convenience. Stubblefield called this capability "learning on demand," and he says it represents an important trend for the industry.

In addition, satellite-enabled distance learning brings many technical benefits to the user as well. According to executives at Helius Inc., a network using satellite supports two-way communications via a terrestrial return; minimizes load on network through scheduling of content delivery; can deliver video, audio, multimedia and data using the same network; users can view content the why they like to via computer, television or video display; and proves time and again secure transmission of all communications. Large dispersed organizations can benefit greatly from implementing interactive distance learning. Given the enhanced rich media of today, a robust network channel can pay off at the end.

Also fueling learning on demand is the growing availability of systems that include hard drives to store material for delayed viewing, similar to the digital video recorders that cable and satellite TV subscribers use to capture programs for later viewing, Stubblefield says. Going forward, "there’s going to be a lot more learning when people want," not when the material they need happens to be available, he says.

Sam Silverstein has been covering the commercial satellite industry since 1995. He is a free-lance writer to Via Satellite.