InformationWeek
Defining The Business Value Of Technology
February 21, 2000
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Whiting says high availability is one of the reasons he's committed to Rite Aid's satellite system. Comsys' Bull says Gtech Corp., a West Greenwich, R.I., lottery systems supplier, uses more than 1,000 VSAT terminals to support lottery sites worldwide--clearly a high-availability application.
Nonetheless, satellites are rarely the easy choice for enterprise data or content transmission. Leased lines or frame relay are still the safe options, in the same way that IBM was the safe choice for computing equipment two decades ago. That's not just out of habit or concern about new technology; from a purely transport perspective, terrestrial fiber offers faster maximum bidirectional point-to-point throughput, at above-T3 speeds, than is likely to be available from satellite vendors. According to analyst Kidd, typical VSAT throughput speeds are around 2 Kbps; they top out at about 45 Mbps. Major terrestrial carriers are upgrading their fiber-optic backbones to OC-192, which transmits data at up to 10 Gbps, and are planning to add next-generation optical routers.
Satellite systems have another drawback. For geostationary earth orbit (GEO) satellites, one of the major issues is the latency inherent in a signal transport path that's 22,300 miles long in each direction. That translates into a time lag of one-quarter of a second for the round trip itself, plus framing, queuing, and switching delays that can increase the latency to half a second or more--far too long a delay to allow effective use of interactive real-time applications.
There isn't much to be done right now about the propagation speed of electromagnetic transmissions. But one satellite negative that's rapidly being addressed is the previously proprietary nature of the systems and a lack of interoperability standards. Ron Clifton, president and CEO of International Datacasting Corp., a supplier of satellite multicasting systems, says the typical enterprise sale today is to an IS executive rather than a satellite specialist.
In response to this migration from early adopters to repeat business, Clifton says, "We had to go to standards. We had to go to plug-and-play." He didn't want satellite equipment to look different from anything else that plugged into a LAN. For example, the company's satellite receiver has an RJ-45 plug, so it looks like another PC when it's plugged into the LAN. The key is to make sure the IS person is comfortable with the equipment, and that it's easy to manage. (Simple Network Management Protocol is available.)
Software compatibility is another essential standard for enterprise satellite use. Given the booming demand for Internet access and the growing business reliance on IP networks, satellite compatibility with TCP/IP is particularly important. Latency plays a role here as well, since the delay inherent in the use of GEO satellites is long enough to disrupt the acknowledgement handshaking that is at the core of the packet transmission system. To ensure usability, vendors are scrambling to deploy solutions that include data compression, packet spoofing (fooling the sending TCP/IP system into continuing to transmit data before acknowledgements are received), and caching frequently accessed Web data close to the requesting systems. That way, delays in accessing that data will be lessened.
Both Media DVX and Rite Aid run IP data over satellite links using DVB, an emerging standard that embeds IP packets in MPEG2-encoded data. Rite Aid transmits its company data over Gilat's SkySurfer system, which supports intranet access as well as video and training broadcasting. In addition, the company is exploring using the system to push documents out to the store, cutting down on paper documentation. Media DVX uses PanAmSat Corp.'s SpotCast technology.
Satellite analyst Kidd anticipates the next generation of satellites, expected over the next several years, will deliver business users a radically lower price point, exponentially expanding the market. And Myron Mosbarger, president and CEO of Helius Inc., a company that provides satellite data products, predicts that the satellite pricing model will move away from dedicated bandwidth, where a company owns a particular time segment whether it's using it for data transmission or not, to a shared model, similar to frame relay.
As Bull says, part of satellite transmission's problem is perceptual. "One of the challenges the VSAT industry faces is taking the message of how competitive the technology and services can be right up to the board level. As of yet, most board members and high-level company executives rely on their technical wizards. It's the usual kind of thing: There's an element of laziness there." He notes, for example, that the U.S. financial community accounts for only slightly more than 9% of all VSAT terminals sold here. For Latin America, that figure is 14%, and for Asia, 33.5%. Why? Bull says it's because the perception that satellite is second-rate technology won't let it through the enterprise door.
A spokesman for Wells Fargo Bank in San Francisco says that the bank relies on land lines for its high-speed connectivity, saying satellite usage doesn't offer the reliability the bank requires. That, Bull says, is neither accurate nor fair.
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Illustration by Brian Raszka
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