Ka-band Satellites: Chasing Data-Centric Dreams
By Peter J. Brown
In, “Ghostbusters” it is a matter of whom you are going to call. In the emerging realm of two-way broadband multimedia via Ka-band satellite, it is a matter of what it takes to make it a reality, and how soon we will see it happen.
Some readers will argue that it is happening right now, and that the curtain is going up. However, others question whether the data-centric models driving this Ka-band revolution make sense. For one thing, it is clear that open standards, the availability of low-cost terminals and declining investor confidence in the satellite sector are big factors here.
Jumpstarting the market for broadband multimedia via satellite is not going to be easy, even as Ka-band spotbeam technology, two-way connectivity and high data rates converge into a coherent entity. In addition, do not overlook the potential for a greater role involving hybrid Ka-/Ku-band services in the process. This exercise is all about building demand on a massive scale. Creating and selling cheaper terminals is seen as one of the top priorities in the effort to get the Ka-band ball rolling.
“Terminals in the sub-$350 range are not out of the question. I believe we can get there in the next three years,” says Steve Cable, vice president and general manager of broadband systems at Viasat Inc. in Carlsbad, CA. “Significant progress has been made, but at the same time, you cannot build these in low volumes.”
Cable stands out from the crowd in calling for the satellite industry to embrace the Data Over Cable System Interface Standard (DOCSIS) as its standard of choice for higher volume consumer applications. DVB-RCS simply presents too many obstacles, according to Cable, who sees adaptive techniques combined with DOCSIS as a way to reduce rain fade impacts. He also sees the DOCSIS-driven infrastructure as far more advanced than any DVB-RCS-based alternative.
“We have encountered no predisposition whatsoever to DVB-RCS in the talks that we have had thus far. With DVB-RCS, the return synthesizer drives up the cost of the terminal, among other things, whereas DOCSIS offers scalability and takes advantage of much lower cost, mass-produced chipsets,” says Cable. “In addition, DOCSIS addresses interfaces and applications across the entire business model, and there are third and fourth generation DOCSIS gateways already on the market.”
DOCSIS or not, there have been significant milestones achieved across the board throughout the past 18 to 24 months that are helping everyone zoom in on the target, according to Cable. Having all functionality, including performance-enhancing proxies, built right into the satellite modem, having access to silicon with a significantly higher level of integration surrounding the MAC and physical layer, and having much lower cost Ka-band RF designs in play are all adding considerable punch to the Ka-band market.
Still, while he does not declare it outright, Cable implies that DVB-RCS in its current form is not what the industry needs for the consumer/SOHO (Small Office/Home Office) market.
“The questions surrounding DOCSIS right now center on how well does this cable industry standard port over to satellite and how easily can it be implemented over satellite,” says Steve Collar, manager of satellite plans and procurement at New Skies Satellite N.V. in The Hague, Netherlands.
Collar indicates that there appears to be widespread agreement that DVB-RCS needs a few modifications. “We may see some streamlining,” Collar says.
“DOCSIS is not a system designed for satellite operations. You need additional circuitry on it to drive RF. So, this idea that DOCSIS is somehow cheaper is a myth. It is the ODU, not the IDU which is the driver of Ka-band terminal costs,” says Mike Cook, vice president and general manager of the Spaceway business group at Hughes Network Systems Inc. in Germantown, MD. “Besides, with our processor-based satellites, DOCSIS does not do anything for us,” he adds.
Al Hansen, president and CEO of EMS Technologies Inc. in Norcross, GA, emphasizes the real pricing advantage in the Ka-band sector will be achieved when ODU orders for 100,000 units or more start to flow. Right now, that threshold remains elusive. “The whole thing is so price sensitive, and it is based on quantity,” Hansen says. “Will DVB-RCS change as we go along? Who knows. What I do know is that DVB-RCS is functionally accepted, and EMS is really committed to it.”
EMS is focused on hubs and terminals, and it is currently working on a third-generation terminal. It has been closely involved in the evolution of the Ku-/Ka-band platform which formed the nucleus of the Luxembourg-based SES Multimedia Broadband Interactive (BBI) initiative in Europe, for example. BBI-related development is now shifting to Alcatel as part of the recently announced SatLynx partnership that also brings Gilat onboard.
“We are always looking at ways to reduce the price of the ODU,” Hansen says. “Ka-band is starting to move, and it should arrive in late 2003 or early 2004.”
Other pieces of the puzzle appear to be falling into place quickly. According to Jeff Mathie, president of Patriot Antenna Systems Inc. in Albion, MI, the market for metal satellite antennas in general is in relatively good shape today. As for what lies ahead with respect to Ka-band, Patriot has a new feed available to go along with a transceiver developed by US Monolithics, which was acquired by Viasat last spring.
“Metal dishes not only offer superior surface accuracy, their ability to shed rain has been greatly enhanced with the latest in hydrophobic coating technology,” says Mathie. “The two-way Ka-band products will emerge along with Ka-/Ku-band products, which may actually represent a potentially better market, although these systems are more difficult to mass manufacture in a cost effective manner due to the feed switching requirement.”
New Skies is one of several companies where the Ka-/Ku-band connection is alive and well. For starters, New Skies never bought into any large plans for Ka-band multimedia satellites, according to Collar. New Skies is planning to launch NSS 6 at the end of 2002 to 95 degrees E with 12 super-high-gain Ka-band uplink spotbeams allowing for data rates of at least 1 Mbps. Downlinks use 60 Ku-band transponders offering 51-53 dBW in six beam configurations. The Middle East, South Africa and all of Asia as well as Australia will be able to access NSS 6. “By uplinking in Ka-band and downlinking in Ku-band, we reduce our susceptibility to transmit rain attenuation,” says Collar.
Eutelsat is pursuing a variation of this cross-link strategy as well. Eutelsat W3A, which launches next year to 7 degrees E, includes a mix of Ka-band and Ku-band transponders to allow for an agile high-bandwidth service between northern Africa and Europe in particular.
When it comes to central terminal Ka-band amplifiers, Chelmsford, UK-based E2V Technologies (formerly Marconi Applied Technologies) is refining what it has applied so well with its lineup of stellar antenna mount amplifiers for Ku-band satellite newsgathering (SNG). New Stellar 120-watt Ka-band amplifiers are now available for both military and commercial customers.
“We are delivering our first Ka-band amplifiers. A principal feature of our amplifiers is that we also manufacture the TWT. This offers our customers superior linearity and higher usable power,” says Andy Bennett, communications sector business manager at E2V Technologies.
He indicates that his company’s growing list of orders and requests for amplifier demonstrations are good indicators that the Ka-band market is gaining steam. Still, he is taking a cautious view of what lies ahead.
“If all the global projects materialized, we could see a demand for a 1,000 amplifiers each year. Reality suggests this will be much lower,” Bennett says. “From the standpoint of market stability and growth, the move beyond trial installations of Ka-band is dependent upon a new network emerging.
“It is true to say that for individual requirements for data transfer, it is possible to use the existing infrastructure,” he continues. “However, when it comes to requirements for even moderately sized networks, the capacity simply does not exist,” he adds. “So, the need to use other less congested bands is generated. With the increased bandwidth available at Ka-band, it is becoming the obvious choice.”
Peter J. Brown is Via Satellite’s Senior Multimedia Editor. He lives on Mount Desert Island, ME.