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Ka-band Services: Available In Different Flavors

By | February 10, 2001

      Interactivity and bandwidth on demand reside at the nucleus of the new cluster of emerging Ka-band services where the emphasis is on transforming exciting concepts into profitable ventures. And yet, today’s Ku-band VSATs by themselves do not provide any guarantee of success for the next generation of Ka-band systems.

      Sure, the projections are just too bullish to ignore. For example, The Boston-based Yankee Group sees the number of U.S. households using satellite broadband systems growing from 230,000 at the end of 2000 to 5.6 million in 2005. Roger Rusch, president of Telastra Inc. in Palos Verdes, CA, estimates that approximately 480 Ka-band transponders were on order as of 2000. Projections of Ka-band transponders are not easily assembled given the fact that in the emerging Ka-band realm there are satellite designs that omit traditional transponders altogether.

      At the same time, there are warning flags going up. Last year, NYC-based C.E. Unterberg, Towbin Vice President William Kidd, among others, warned the industry of the risks involved when grossly oversold network capacity collides with a horde of subscribers who become wildly unpredictable, and do more than engage in thin and spotty online activities. How bandwidth gets sliced and delivered is not a secondary concern, especially when the wireless sector is revving on all cylinders again.

      Kidd sees congestion ahead, and urges readers to reflect on Germantown, MD-based Hughes Network Systems’ DirecPC’s experience curve. Kidd asserts that usage itself became the greatest operating risk, rather than any specific attribute of this hybrid Ku-band satellite receive/terrestrial dial-up return path Internet access system which was introduced five years ago.

      As for Ku-band in general, the launch of VA-based Starband Communications’ two-way Ku-band system for consumers– DirecPC is preparing to do the same–as well as the FCC’s recent green-lighting of non-geostationary, Ku-band projects such as Skybridge, underscores the fact Ku-band will thrive in multiple flavors for years, especially now that Skybridge has attracted Qualcomm with its CDMA prowess to its team.

      As for Ka-band, rest assured the savvy group of satellite network performance enhancers stand ready to further supercharge their customers’ assets. For example, Stamford, CT- based Kencast Inc. is introducing Fazzt 6.1 to ensure that forward error correction (FEC) keeps pace with the demands of the marketplace. With the possibility of extended outages looming in the Ka-band domain due to rain attenuation, there is an added emphasis on maintaining the integrity of live streaming content in addition to any large file transfers.

      “As the wavelength decreases, extended outage recovery becomes more critical in both one-way and two-way environments. We are focused on protecting audio, video and data by doing FEC on the fly using what we call wild card packets to reconstruct missing data,” says Lewis Wolfgang, Kencast’s vice president and chief scientist. “As we see customers acquiring PVR functionality, this edge caching dimension via Ka-band makes FEC even more valuable and essential as service providers grapple with a variety of Quality of Service (QoS) issues.”

      Not The Same Old Geo

      Ka-band service providers will fly new satellites, and deploy new architectures. Bethesda, MD-based Astrolink International LLC will start in 2003, and the goal is to operate four GEO satellites with 6.5 Gbps of sellable bandwidth–nine GEO satellites are proposed for the full Astrolink fleet–using onboard processing which is generally viewed as a much riskier proposition than conventional bent pipe satellite-based operations. Hughes’ Spaceway will also be in this category of onboard processing-based players.

      “Using our on-board ATM-based (Asynchronous Transfer Mode) switch and very high EIRP, we can provide full mesh networking,” says Jeffrey Grant, Astrolink’s vice president and chief technical officer. “We will have lots of raw capacity available for use as well. Our goal is to offer symmetrical service with a TDM/FDM (Time Division Multiplexing/Frequency Division Multiplexing) uplink and a 20 GHz TDM downlink.

      “Our satellites are not like today’s GEOs with low data rate commands. Our command rate to our payload will be over 6 Mbps. This is necessary in order to execute the bandwidth- on-demand-based millisecond lease which occurs as each ATM packet moves through our switch and transponders,” adds Grant.

      Astrolink’s spacecraft critical design review was completed last December. A number of related developments were unfolding as the year drew to a close. Astrolink payload provider TRW Inc. of Redondo Beach, CA, who has a stake in Astrolink as well as in Denver-based Wildblue Communications Inc., announced in November that it had created a highly miniaturized upconverter that will make its debut on the Astrolink satellites. TRW, along with Lockheed Martin Global Telecommunications, Telespazio, a subsidiary of Telecom Italia, and Denver-based Liberty Media Group, have invested $1.5 billion in the Astrolink system thus far.

      Given that each spotbeam requires its own upconverter and traveling wave tube amplifier (TWTA), this massive reduction in the size of the upconverter by TRW opens the door to an entirely new configuration of spacecraft components. In effect, an upconverter can now be mated directly to the TWTA’s power supply–gone is the requirement for separate power supplies for both components–while, at the same time, placing the upconverter in closer proximity to the TWTA substantially shortens the pathway for all signals flowing through the spacecraft, which reduces signal loss substantially.

      TRW also announced last summer that it was acquiring a 10 percent stake in Quebec-based Spacebridge Networks Corp., a move associated with TRW’s long range plans for a global extremely high frequency satellite network, among other things.

      Last fall, Astrolink announced that Carlsbad, CA-based Viasat Inc. would supply two-way, Ka-band VSAT earth stations which will be capable of 100 Mbps downlink and 20 Mbps uplink speeds.

      “By using an ATM transport layer, we can easily integrate into existing and future terrestrial infrastructure. But we are not simply offering transport, rather we intend to be capable of handling applications such as data caching and VPN services,” Grant says.

      Steve Cable, vice president of Viasat Broadband Systems, indicates that while Viasat will be supplying Ka-band terminals, it will also be purchasing broadband satellite services from Astrolink so that Viasat can cooperate with Astrolink in offering value-added broadband services to its VSAT customer base.

      “By becoming both a co-exclusive terminal supplier, and by securing prepaid Astrolink airtime, it is the best of both worlds for us. We can provide bundled services, while at the same time, we are not being transformed into a satellite service company,” Cable says.

      Other broadband satellite-related projects are underway at Viasat including a Ku-band project that will launch in late 2001 using Viasat’s asymmetric Paired Carrier Multiple Access (PCMA) technology. Along with PCMA, Viasat is incorporating its Code Re-use Multiple Access (CRMA) technology for more than one satellite system. According to Cable, CRMA enhances the benefits of asymmetric PCMA.

      “With interactive access services over Ku-band and Ka-band satellites, the return path traffic flow in particular will produce an unpredictable variety of traffic. While we have not deployed CRMA yet, it is designed to optimize both the interactive access network’s performance and the end-user’s experience in that multiple connection environment,” Cable says. “Like any access scheme, we try to make it transparent. Immediate access over common bandwidth is one way to achieve flexibility and efficiency from both a cost and performance standpoint.”

      Docsis Over Satellite: Just One Of Many Possibilities

      Late this year Wildblue–formerly known as iSky–is scheduled to launch its Loral-built Wildblue 1 Ka-band satellite at 109 degrees W in preparation for the initial roll out of Ka-band services in the United States in early 2002. Wildblue 1 will be followed by Wildblue 2 at 111 degrees W in late 2002, which will use 45 Ka-band spotbeams or 90 percent of Ontario-based Telesat Canada’s Anik F2 Ka-band payload, an arrangement subject to FCC approval. As this article was going to print, Wildblue executives were not available for any wide, open interviews as they were still in a quiet period as dictated by the rules and regulations of the U.S. Securities and Exchange Commission.

      “We expect significant competitive factors to include price and transmissions speeds. We plan to price our monthly subscription fees to be competitive with current terrestrial broadband Internet access services. We also expect to offer our residential customers affordable two-way Internet access at speeds of up to 1.5 Mbps. In addition, we expect to offer a premium connection of up to 3.0 Mbps for SOHO –Small Office/Home Office–and other bandwidth-intensive consumers,” says Brad Greenwald, Wildblue’s vice president of business development.

      Company documents indicate that Wildblue is aiming for a price range of $249 to $399 for the initial Customer Premise Equipment. With frequency reuse, Wildblue estimates that Wildblue 1 and Wildblue 2 will have an aggregate upstream and downstream bandwidth of 6.0 GHz, whereas existing Ku-band satellites using the same amount of radio spectrum would have an aggregate bandwidth of only approximately 1.6 GHz, or approximately 25 percent of Wildblue’s bandwidth. Six fixed gateways installed at network access points will beam outbound IP traffic to subscribers.

      “We are looking at multi-Gbps per satellite. By selecting a bent pipe satellite, we have adopted a lower risk approach. Besides, we know that our residential and SOHO customers will be looking for straight Internet access, and not an overlay to the Internet,” says Greenwald.

      Although it has selected the so-called DOCSIS or Data Over Cable Service Interface Specification standard that has been adopted by the cable industry to speed the deployment of cable modems, Wildblue is not closing the door to other standards as it seeks to establish the lowest cost approach for consumers and businesses alike. Thus, Wildblue’s proprietary satellite modem termination systems will duplicate the intelligent processing that is provided by its terrestrial counterpart, the so-called Cable Modem Termination System (CMTS), which serves a dual role as both a shared bandwidth management platform and RF converter to handle Internet protocol packet switching.

      “We want to offer the most affordable service, and the lowest cost per bit in space based on standardized off-the-shelf customer premise equipment including an appliance-based modem. We see DOCSIS in the satellite realm as a toolkit which is well suited for a different physical layer and higher latency environment,” Greenwald says.

      According to Toby Farrand, president and CEO of Milpitas, CA-based Broadlogic Network Technologies, although DOCSIS was not originally designed for two-way satellite networks, it can be adapted.

      “DOCSIS along with DVB-RCS will dominate two-way satellite applications in the coming decade,” says Farrand. “We view DOCSIS as a toolkit with many functions that may or may not have a place in any particular network. Networks such as Wildblue that adopt DOCSIS will leverage off of many of the proven capabilities and infrastructure that the cable industry has developed.”

      An Eye Out For Innovative Methods

      While the communications systems group at Colorado Springs, CO-based ITT Industries is best known for its Milsatcom-related work in areas such as tactical broadband platforms, it plans to extend this capability into the commercial Ka-band market. And in order to do so, it is developing both a Ka-band earth station ensemble (ESE) as well as a Web-enabled carrier performance monitoring (CPM) capability to allow satellite users to verify their service level agreements (SLA’s). A good deal of energy is being devoted to exploring all aspects of modem and baseband switch interactions.

      Looking at ATM-based networks with both variable bit rate and constant bit rate traffic, ITT Industries believes that much work still needs to be done with respect to how SLA’s are structured and used over satellite links, and the ESE constitutes a second or third-generation Ka-band solution that leverages off-the-shelf equipment to the maximum degree possible.

      “Our focus is on the service level agreement policy mechanism, among other things, and the translation of QoS parameters between the metrics of one network, and another,” says Larry W. Krebs, vice president of strategic programs at ITT Industries. “Our Web-enabled CPM capability is focused on real-time monitoring and link assignment schemes for existing SATCOM systems.”

      Krebs indicates that ITT is evaluating user throughput adaption using better performing modulation techniques and encoding schemes such as 8PSK or 16 QAM with rate 5/6 or rate 7/8 coding as opposed to traditional QPSK with rate 1/2 coding to mitigate the effects of rain attenuation.

      “We are evaluating commercial modems with a wide range of modulation and encoding types, and as far as our requirements for demonstrating adaptive modulation are concerned, it looks like the Newtec NTC 2063 DVB demod is a possible candidate,” Krebs says. “The modem is the key here. By doing data rate adaption with this unit, we can accommodate a 12 dB fade in the carrier-to-noise ratio in the link in question.

      “Some solutions insure link availability with a lot of static margin, and operators seem willing to accept this unused capacity as a cost of doing business in a circuit- switched transmission model. However, the evolution of Ka-band broadband satcom to a packet switched transmission model provides some opportunities for innovative adaption methods,” Krebs adds.

      Trying to maintain link quality by strictly using link power control is problematic given the depth and rate of fades in Ka-band, according to Krebs, so there is a need for a more responsive control system than is available with centralized link power control.

      “It must be done autonomously on a link by link basis,” says Krebs, who stresses that QoS-based provisioning with data rate adaption based on different modulation and coding schemes where power input to the satellite is left unchanged is the way to go.

      “As you evolve toward automated service management options, you want to avoid complex DAMA-type provisioning systems which are overplayed on the network,” Krebs says.

      Hybrid Terminals

      David Price, vice president of business development at San Diego-based Harmonic Data Systems, discusses what was on the horizon two years ago in order to stress how difficult it is to project where we will be two years from now.

      “Two years ago, there was good deal of skepticism about RF component price projections. Now, most people are quite optimistic,” Price says. “Service providers can see a real path. Significant efficiency improvements have come into the return channel systems in particular.”

      “Service providers want an easy upgrade path to Ka-band which negates the idea of an integrated IDU/ODU in one box, but they want it in a Ku-band launch mode with the radio as a discreet element that can be swapped over,” Price adds. “The industry is trying to architect everything so it is easy to change in terms of RF upgrading, for example, and so the system can be dovetailed to whatever comes next. People just do not know how the marketplace will look in two years.”

      Price says that the emphasis on two-way platforms represents a quantum shift on the ground in terms of what is required to properly install these units, and that having put the fundamentals in place at the component level is just the tip of the iceberg.

      “The process is complicated, and in a sense, it represents a significant obstacle. The skill set for one-way services cannot be applied to two-way services. The possibility that you could end up beaming to the wrong satellite is just one of many new twists that pop up,” Price says. “From one site to the next, you cannot know the exact configuration. In effect, it is a whole new business model absent the higher margins that have been part of the previous VSAT economic model.”

      Price disagrees with people who see the Ku-/Ka-band hybrid platform such as the system recently deployed by Luxembourg-based SES Multimedia as niche platforms, or the exception rather than the rule.

      “Ku-/Ka- hybrid terminals will be quite common. There is no point in having multiple spotbeams for a multicast service. Ka-band can just be used for the return path,” Price says. “Putting conventional DVB video on Ku-band, and simultaneously putting data on Ka-band is another option. Ku-band will continue to have a lot of good space segment. Small networks will find it hard to justify Ka-band, and thin or no request services that just push content will probably stay with Ku-band as well.”

      We Need Volume

      The Ka-band market will mature eventually, but it will need a bit of a boost in its formative or early stages. This is no secret. Part of Wildblue’s strategy, for example, involves the purchase by Wildblue of a 35 percent stake in Mesa, AZ-based U S Monolithics, a designer of satellite and terrestrial wireless transceivers. However, the plan here is not to simply buy a stake in a top contender in this sector–other companies to note here include Raytheon, Norsat, Endwave, Newtec and Remec–but to do whatever it takes to grow the market for the higher cost/higher risk outdoor units (ODU’s).

      “Wildblue did not seek an exclusive arrangement. They want us to provide them with low-cost units. To do this, we need volume, and so we need people who are willing to make the leap by putting orders in for larger quantities,” says Dean Cook, vice president of engineering at U S Monolithics. “We are also working with other satellite service providers to standardize the transceiver. We will outsource the production of these units. This enables us to enter the market with lower capital investment.”

      Cook indicates that U S Monolithics is offering its comprehensive Monolithic Microwave Integrated Circuits chip set to both Ka-band or terrestrial Local Multipoint Distribution System service (LMDS) providers, and that “there is enough market for both of them to take hold.”

      With the launch in late 2000 of two-way satellite broadband services for the consumer involving retailers such as RadioShack, for example, with attractively priced hardware points and competitive monthly rates–kiosks featuring Microsoft Corp.’s MSN services and Starband Communications’ two-way Ku-band Internet access platform can be found at RadioShack–the average consumer is about to be re-educated about what it means to access the Internet, while the accepted definition of “niche” in the satellite industry may have to be discarded. All of this is unfolding as the Internet’s power to attract customers is showing no signs of abating.

      Peter J. Brown is Via Satellite’s Senior Multimedia Editor. He lives on Mount Desert Island, ME.

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