Ground Players Tackle Bandwidth Optimization in an HTS World
For any industry, making the most of the resources you have available is critical to success. The managing of bandwidth for the satellite industry is vital particularly as we look at things like 4K and move into a more data-intensive world.
The launch of ViaSat 1, Intelsat Epic NG and other new High Throughput Satellites (HTS) is increasing the amount of bandwidth in the sky by a factor of eight to 10. At the same time, the promise of performance embodied by HTS has upped the stakes for the ground segment to devise new ways to squeeze more efficiency out of existing networks while ensuring that infrastructure investments made today will serve customers needs for broadband on the fly tomorrow.
“Our customers are demanding much more dynamic delivery of service from us,” says Andrew Lucas, global operating officer for Harris CapRock, which teams with iDirect and Comtech EF Data to serve customers in the maritime, energy and government sectors. “In our world, a customer may be in a location for only a short period and then change, but they may not be able to tell us where they are going next. We need to deliver very quickly.”
Mark Ayers, director of RF satellite engineering for Alaska-based GCI, a voice, data and video services provider, is also feeling the pressure to serve more demanding users, especially as it delivers high-bandwidth to schools and clinics in rural Alaska for applications such as telemedicine. “We’re highly focused on being as efficient as possible with our bandwidth because of the high cost of satellite capacity,” he says. “Every single link we deliver is focused on maximizing the spectral efficiencies we can achieve.”
Some communities in Alaska may never have access to terrestrial services because of the high cost and extreme challenges associated with delivering the service to these remote locations, according to Ayers. Satellite, he adds, will persist even in places with terrestrial services because the links need the redundancy provided by satellite systems.
“Our satellite utilization has gone up year over year for the past five years, even while GCI invests heavily in converting many communities in Western Alaska to terrestrial microwave/fiber platforms” Ayers says. To support high-bandwidth applications for schools over Ku band, GCI is adopting Adaptive Coding and Modulation (ACM)-based links using Carrier-in-Carrier or PCMA, which will allow him to get higher information rates while providing continuous service during significant rain fade events. The technology provides efficiency gains of approximately 10 to 15 percent during clear sky conditions while customers can survive much deeper and longer fades.
“You get huge amounts of margin and your continuity of services improves drastically,” says Ayers, who explains that GCI hasn’t adopted this technology as quickly as he would like because the Quality of Service (QoS) tools are not as far along as he would like. “The modem manufacturers have recognized the need for the QoS piece for the last few years. The QoS tools are under development but the technology isn’t quite there yet for me to have the confidence to put carrier-to-carrier in place with ACM on a wide scale yet. I aim to adopt it in some capacity this year.”
The bandwidth challenges facing GCI and CapRock’s oil and gas operators are far from unique, but some of the innovations coming out of industry represent promising answers to the bandwidth optimization challenge.
Herndon, Virginia-based VT iDirect is one of the ground players addressing the QoS issue. Its Adaptive TDMA solution with embedded group QoS was first introduced in 2013. According to Greg Quiggle, iDirect’s VP of product management, the solution essentially gives a terminal a broad choice of carriers to pick for the return channel, and those carriers can take advantage of a wide beam or HTS capacity. “This allows the terminal to essentially pick carriers on the fly from carrier to carrier and allows you to always have optimal bandwidth performance on the return, which in the end leads to better efficiency and better throughput.”
Quiggle adds that as the terminal flips from one carrier to another, or from wide beam to spot beam, it can prioritize traffic flow. “As our customers have expanded to HTS, we’ve allowed the system intelligence to make a lot of those decisions for them — what is the best beam for a given terminal to use given its RF profile or the importance of the traffic moving over the node,” he says.
Last May, Harris CapRock launched its Advanced VSAT solution, which allows service providers to dynamically reassign satellite capacity on demand by leveraging Comtech EF Data’s efficient modem technologies and the Vipersat Management System. Recently, an oilrig customer in the North Sea used the technology to change on-board operators in real time.
Comtech is tackling optimization via a multi-layer approach, providing maximally efficient modulation and coding that adapts to weather conditions on the fly in both directions, frequency reuse via its Carrier-in-Carrier technology, intelligent optimization of the data stream itself along with dynamic bandwidth allocation.
Steve Good, VP of marketing for Comtech EF Data, insists that this is not just about efficiencies in the physical layer. “It’s about efficiency teamed with intelligence and having the horsepower to perform these operations at high throughputs. Ground equipment has moved from being unintelligent devices passing everything that comes into it to highly intelligent analytics engines that understand the traffic mix it is supporting and make decisions on how to optimally support the underlying protocols, sending only essential data over the satellite link with the proper QoS while assigning precious satellite bandwidth accordingly across a network. Intelligence is key to providing the most net efficient link possible — the ability to dynamically allocate bandwidth per application and horsepower to support these is essential,” he says.
Ultra-HD Video Takes Hold
Researchers inside Bell Labs, Alcatel-Lucent’s Research and Development (R&D) organization, are focused on another optimization challenge — how to make use of small slivers of spectrum that operators historically have dismissed as unusable because they are in the portion of the spectrum that is noisy.
“We’ve reinvented some ways to use portions of the spectrum, particularly spectrum thought to be unusable and was laying fallow,” says Paul Wilford, director of the Video and Broadcast Research Group at Bell Labs, referring to Virtual Spectrum Aggregation (VSA). To date, Alcatel-Lucent has been able to show high definition signals over the VSA links, and most recently expanded from four to eight links. VSA will enable companies to virtualize resources in the network; that is, pool them into common assets that can be shared and allocated at different time spots for different uses.
VSA’s significance is it will allow users to get the most from video transmissions with the advent of Ultra-HD video, says Wilford. He believes that the breakthrough will change how people view spectrum. “People won’t think about it as a fixed point in the sky, but as a dynamic asset that they can manage automatically,” he adds.
Without question, Ultra-HD is coming. NSR’s newly released “Ultra-HD via Satellite” report indicates that the global satellite Ultra-HD market is expected to reach $412 million in 2025 from an $8.2 million revenue base in 2015. Broadcast IT planners are already factoring it into their plans but the two-way data market will also see its impact in the coming years.
“Where Ultra-HD will start to show up in the return channel is in ISR and UAVs since they deal with very high-res video at a terminal site and they need to get it back to a location,” explains Quiggle, who says the defense market accounts for 30 percent of iDirect’s business today.
The coming of Ultra-HD already is challenging players to developing higher performance spectral efficiency than what is possible from the new DVB-S2X standard. Some players feel that the latest standard doesn’t do enough to improve satellite bandwidth optimization.
“HD was the main compelling event and catalyzer motiving the market to replace DVB-S with DVB-S2,” observes Oscar Glottmann, executive director and CMO of Israel-based NovelSat, who says as 4K/8K/Ultra-HD penetration ramps up in 2017-2020, history will repeat itself. “S2X offers too little,” he says, adding that DVB-S3 will be required but probably won’t be introduced until 2016-2017, delaying planning of Ultra-HD deployments.
NovelSat isn’t the only company pushing for more capabilities and coverage beyond what DVB-S2X delivers today. In November, Comtech launched VersaFEC-2, the company’s second-generation modulation and coding scheme for their advanced satellite modems, specifically for this mid and low-data rate market.
“The DVB-S standards were designed to support links of tens or hundreds of Mbps. What’s missing in the standards is the support of lower data rates,” notes Good, explaining that the block size of the DVB-S2 standard creates a great deal of additional latency on the link, which is the last thing satellite users want to deal with. Good calls VersaFEC-2 “a major step forward” for the industry to address the low to mid-range data link segment of the satellite sector not currently served by the standard. Quiggle defends S2X as a positive development, especially in light of the challenge inherent in trying to establish consensus across the industry. “Could the standard have gone further? Yes. You can always go further with any standard. I judge it more on whether there has been a gain. I think there is substantial gain over S2 and as a result, it will be valuable for our industry.”
A Look Ahead
Many of the ground-based innovators remain upbeat about the future as HTS is deployed worldwide. “Ultra-HD’s entry into the mainstream opens huge demands for additional bandwidth,” says Glottmann. His company is already working on NovelSat NS4 to extend the efficiency of its NS3 product to more than 50 percent improvement over DVB-S2X, and to provide customers the option of using both fully compliant DVB-S2X as well as NovelSat’s proprietary efficiency improvement technologies.
“We want to leverage HTS, and give our customers the best characteristics of all the different alternatives that are becoming available,” says Lucas. “Our customers are demanding much more dynamic availability from us and I think it will be available to them all should they require it. I expect this to become a default mode of operation.”
Lucas adds that as customers require bandwidth coverage at an unpredictable point in time, such as bandwidth upgrades to enhance remote operations, and expect 100 percent availability during that period, it will force the industry to rethink how it defines service level agreements.
“HTS brings the need to constantly improve symbol rates both on the hub side and the terminal side,” notes Quiggle, who predicts that in the next two to three years, mobility networks will be predominantly HTS-based. “Although we’ve made some great strides in improving those on an annual basis, you can never claim victory.”
While iDirect and other players continue to focus on making beam performance better, the bigger challenge Quiggle sees for the industry as HTS ushers in dramatically more capacity is much more basic: “How can we make satellites easier to use? How can make it a more open technology? … It’s not just about optimization; it’s about making it very easy to use satellite just like it’s easy to access technologies like metro Ethernet or Wi-Fi or 3G and 4G.”
Today, these technologies seamlessly integrate with the core network, which allows for design, deployment and management processes to be automated. “When you go to satellite, in many cases that’s all a manual process — it’s a very heavily engineered process to get a network running and properly integrated with its core IT network,” Quiggle says, observing that as HTS requires the industry to scale quickly, this proprietary approach will slow the industry down in being able to keep pace with deploying capacity. “iDirect is expanding its IP networking options, service providers will now be able to deploy various to standards-based Layer 2 architectures.” The result, says Quiggle, “is it makes our satellite link look like a really long Ethernet cable,” which will make it very easy to apply industry-standard communications equipment on the terminal side to speed adoption.
“It’s an exciting time to be in this industry — we are at a tipping point with new satellite designs coming on, new players entering in the market and new business models being developed,” says Good. “Some folks believe they can’t afford satellite communications any longer with the new terrestrial options available to them but that’s assuming the old economic model.
Moving forward, service providers and mobile operators can’t afford not to embrace the new satellite and ground innovations available to them to differentiate themselves and create a new economical service level model.”
“The ability for satellite service providers to manage their scarce and valuable resources as a pool is the essence of Software Defined Networking – and that is path that we’re working towards with great innovation. This is our view of the future for this industry,” says Wilford. VS
Anne Wainscott-Sargentis a communications consultant and writer who brings nearly two decades of writing experience in the aerospace, satellite, telecommunications, defense, and government sectors.