Internet Technology: Pushing The Limits - Page 1 of 3

Peter J. Brown

With its ability to instantly deliver Internet Protocol (IP)-based video, voice and data anywhere in the world, the satellite industry is simply giving the public and private sectors more options. A few vertical industries where satellite technology offers solutions include health care, energy, public safety, transportation and Homeland Security, each of which has unique requirements that are ideal for IP over satellite. But regardless of market segment, enhancing IT technology and maximizing bandwidth usage with satellite is providing profitable returns for global satellite industry executives.

"There is a large market for corporate networks within the enterprise arena," says Paul Kosac vice president of market development, media networks/headend, transmission networks systems for Scientific-Atlanta. "Point-of-sale, product information, instructional video and training opportunities are increasing for clients to cache through an IP network. The common denominator is time, with a growing demand for non real-time applications ."

Kosac adds that as non real-time distribution is used more, users can create niche networks where highly-targeted content can be produced. "As you look at how this is growing, IP distribution is a viable and cost-effective approach for such information to reach the desired audience."

Along with enterprise, government agencies and broadcasters are also growing markets and some satellite equipment providers view these arenas as the two sectors that are accounting for a huge spike in IP over satellite traffic. "The applications are not exactly exotic," says Howard Barouxis, director of sales at Thales Broadcast and Multimedia.

"As for the broadcasters, they are increasingly using satellite to send content in non-real time as IP files over DVB. This extends to their broadcast contribution links, DSNG [Digital Satellite Newsgathering] and flow of syndicated content as well. I see the station group market as very wide open to this type of approach."

Thales offers its Opal IP Encapsulator (IPE), IP receiver and OpenStream multicast solution as well as the Thalescrypt conditional access system, which Barouxis describes as ideal for broadcast contribution links. For example, PBS is currently using a Thales Opal IPE as part of its next generation interconnection system trials, which involve several PBS stations that have been equipped with Omneon video servers. These stations are fed certain PBS primetime shows automatically, but they are also able to access archive material or content on request via a 16 QAM IP satellite link.

According to Bob Hansen, senior vice president of global sales and marketing at Arizona-based Comtech EF Data Corp., IP over satellite links for file delivery using 8PSK, 16- QAM and Turbo Product Code modulation, as opposed to QPSK, are now being evaluated by broadcasters who want to employ this mix of push and pull technology to reduce their bandwidth requirements in heavily automated environments.

"The broadcasters are shifting their attention to processing equipment that includes encoders and modems, along with IP conversion and streaming solutions," says Hansen who recognizes the IP over satellite-based application opportunities as DSNG, Voice over IP (VoIP) with priority, IP videoconferencing, broadcasting video streaming and IP Multicasting. "We hear that broadcasters are transmitting HDTV [High Definition Television] at 30 plus Mbs just to get the full 19.4 Mbs down the pipe. This is one reason why there is such demand for DVB-S2 and fully optimized video compression."

Comtech EF Data also is equipping its modems with Skipware as a performance enhancing protocol. In addition, late last year Comtech announced that it was teaming up with Stockholm-based Effnet Group AB, and that Effnet's Compressed Real-time Transport Protocol (CRTP) and IP Header Compression (IPHC) would be offered as part of the Comtech IP- enabled modem product line-up. CRTP and IPHC are designed for real-time point-to-point links where satellite operators and service providers want to reduce the load requirements imposed by the transmission of IP, UDP, TCP and RTP headers.

"What we see straight ahead is a wholesale upgrading of modems, and a greater need for our expertise in satellite links in general. With a physical link, it is either on or off. But in the satellite world, [due to such things as fading] things are not off or on," says Hansen. "With our line of CDM IP modems, we compress everything from the payload on up, and we flag things differently if a link is degrading, and bit error rates are way too high. We can employ dynamic header compression based on link conditions as well."

The U.S. military looked hard at the Skipware product known as Space Communications Protocol Standards (SCPS. Ongoing TCP-related performance problems including high bit error rates were experienced throughout the last few years on the U.S. Defense Department's (DoD) secure 512 kbs satellite network known as SIPRNET. This led to 18 months of hardware platform testing by Booz Allen Hamilton, according to Nick Yuran, director of sales and marketing at Global Protocols Inc. whose staff developed SCPS. As a result, the use of TCP- based SCPS via Comtech EF Data's turbo IP link accelerator received a major boost from DoD, which specifies turbo IP as part of its requirement for the use of SCPS at the Standardized Tactical Entry Point (STEP) transport layer.

"SCPS exists as a reference implementation, and anyone can put it on a hardware platform. SCPS keeps everyone in the open source domain, and it is a wireless protocol that has been modified to perform superbly in a stressed environment," says Yuran. "In this instance, turbo IP has won out when it comes to providing rapid recovery from dropped packets, among other things, as part of a fully interoperable TCP-based solution. With SCPS at the transport layer, UDP-based VoIP and IP video is not disturbed in any way. In a typical 2 Mbs link, for example, with 256 kbs always allocated for voice, there is no starving of TCP or UDP."