by Colin Mackay
The Digital Video Broadcast for Satellite (DVB-S) Standard is well known and heavily used throughout the satellite Industry. Though initial adopters used this transmission format as a way to efficiently deliver TV programming, it wasnt long before DVB-S became a method of choice for two-way services as well. Release of the DVB-RCS Standard enticed manufacturers to develop duplex communications products and architectures as another step in the relentless pursuit of satellite-spectrum efficiency.
Following approval by ETSI (European Telecommunications Standards Institute) in November of 2006, the newer DVB-S2 Standard was born. The new standard yielded greater spectral efficiency, due in part to improved stability, and allowed for the use of high-order modulation schemes and more powerful FEC coding.
Add Low Density Parity Check (LDPC) and the efficiency gained rivals that of competing technologies that use complex and operationally cumbersome signal cancellation techniques to superimpose transmit and receive carriers on the transponder.
Earlier this year, Paradise Datacom launched the Vision PD80, the Companys first DVB-S2 satellite modem, as well as their latest creation, Quantum. Why two new modems in one year and why now, you may well ask?
We deliberately delayed entering the DVB-S2 marketplace. This has given us some advantages. First, we didnt have to pay the high pioneering costs prevalent a few years ago to acquire the technology. We knew we could offer extremely cost-effective solutions to our customers and help speed up the industrys migration to DVB-S2.
Secondly, many of our competitors designed their products specifically for the high-rate digital video broadcast market, resulting in expensive offerings with limited features. Though we wanted to address that market as well, unique features in our DVB-S2 products have afforded us an advantage in other applications, such as cellular backhaul, which makes up the largest part of our existing modem market.
We intend to break the myth that DVB-S2 is an expensive technology aimed at high rate video. We realized that the space segment savings of DVB-S2 could be equally applied to traditional low-rate SCPC links.
For broadcast video applications, the Vision PD80 will accommodate the conventional ASI and Ethernet terrestrial interfaces, including an onboard ASI multiplexer that will combine as many as four ASI streams onto a single carrier.
The Vision has two distinct differentiators. First, the modem has the most comprehensive set of IP features of any DVB-S2 modem available today, courtesy of what was already resident on the Evolution. IP Encapsulation is performed inside the modem with no need for external hardware.
Secondly, weve been able to launch the product with extremely competitive prices through the use of state-of-the-art technology that wasnt even available two years ago.
For their customers who require conventional SCPC modem features such as ESC, AUPC, Extended D&I, a wide range of physical interfaces such as G.703, HSSI, LVDS, IP, EIA530, as well as traditional IBS and IDR services, the Company introduced Quantum, their Ultimate SCPC Modem.
Quantum allows customers to continue with their existing services and gives them the ability to switch on DVB-S2 when upgrading or installing new links. In effect, Paradise Datacom created a new satellite standard combining the best of SCPC with DVB-S2. Customers who need the old satellite framing for interoperability with other existing equipment (for example, to implement a DVB-S2 outbound carrier with SCPC return) can have that as well.
Consider this; a cellular backhaul customer will typically save 15 percent satellite bandwidth simply by changing from TPC turbo coding to DVB-S2. Paradise Datacom found DVB-S2 is remarkably stable in terms of working lower into the noise and is able to operate with higher order modulation schemes to save even more bandwidth. This is because the modem was designed for the DTH market, where receivers have relatively poor Eb/No performance.
Right now, we have Quantum modems delivering a hybrid E1/IP GSM backhaul channel comprised of multiple E1s + IP with IBS multi-destination Drop and Insert, courtesy of our unique MultiMux interface. This is combined with an ESC channel that is providing a mixture of serial M&C communications and AUPC all over DVB-S2. In addition, the IP stream is being processed in the modem to provide TCP acceleration, header compression, and dynamic routing, all simultaneously. Finally, our proprietary Adaptive Signal Pre-distorter actively compensates for non-linearities to further improve overall link performance.
It is naïve to think our customers will simply migrate from conventional SCPC to SCPC/DVB-S2, unless that transition is compelling, inexpensive, and painless to implement. As transponder prices continue to climb, the market demand for technologies and products that make maximum use of space segment will rise as well. In addition to being spectrally efficient, these products should be cost effective and easy to use. What is important for Paradise is that we have now established ourselves as pioneers helping to enhance the appeal of DVB-S2. This is done by reaching out to a wider audience and helping to speed up the migration to this exciting new technology.
About the author
Mr. Mackay has significant expertise in embedded system software, TCP/IP protocols, satellite modems and professional project management. He specializes in the area of Internet and IP backhaul over satellite. He has been an employee of Paradise Datacom for 6 years and is responsible for managing the Modem Development Group.
He has been intimately involved in the design and management of many Paradise development projects, including the highly successful and novel start-from-scratch Evolution modem.
As well as management and technical expertise in various areas, Mr. Mackay is responsible for Paradises product roadmap and evaluating emerging technical standards and industry trends. He has considerable experience outside of the satellite industry, mainly in advanced radar systems and digital video surveillance systems.