Bandwidth Management and Optimization
Bandwidth management and optimization must address endpoint operational demands with superior quality of experience, while delivering reliable services that are economical and affordable. Overlapping technologies provide unique opportunities for innovation and investment, especially when viewed in the light of market movement toward HTS not only in GEO, but also in MEO and LEO as well.
Since bandwidth is a finite resource, making the most of it and using it efficiently is undeniably critical to the telecommunications industry. However, user needs are changing, and bandwidth usage is becoming more multifaceted.
“The satellite industry has a long and fruitful record of innovations in bandwidth management," says Carlos Placido, senior analyst at NSR. “I expect the industry to fully embrace the potential of virtualization and new techniques that function at the core network or ‘cloud’ level. From software-defined networks to software-defined satellites, there will be an increasing relevance of smart software.”
Itzik Wulkan, co-founder and chief executive officer at Israel-based NovelSat, agrees with Placido. “Demand is growing — this is clear in many markets,” he says. “Just look at cellular backhaul. Bandwidth increases by about 80 percent annually, and this reflects the need for satellite bandwidth.”
Drivers for greater bandwidth include increasingly connected devices, the Internet of Things (IoT), all-digital news content, and Internet-based video demands. Furthermore, anywhere/everywhere connectivity expectations require new types of delivery models.
“At the site level, which is obviously created by ever increasing demands for bandwidth at the user level, I don't know anybody now who carries only one IP enabled device with them,” says Andrew Lucas chief technology officer at Harris CapRock Communications. “It used to be that you carried a phone and did some text messaging. Now I'm pretty sure that you have your laptop, your iPad, maybe one or two phones and a couple of other devices — kindles, watches, who knows — all [of which] are IP-enabled, all of which connect to the network, and all of which are creating and consuming bandwidth.”
Additionally, Wulkan says, “cellular networks are experiencing peak demand all at the same time, so you cannot assume a homogeneous spread over the [whole] day.”
A different perspective emerges for end-users that are mostly rural in nature, such as GCI, the largest provider of telecommunication services in Alaska. The types of anchor services it delivers to schools and clinics are frequently for safety purposes, and often form the primary wireless presence in remote villages.
“In the past two years,” says Mark Ayers, director of radio frequency engineering and network services for GCI, “the healthcare and schools access domain ... those particular markets are very big growth areas for GCI in our satellite segment. We also see growth in the Internet consumption areas, which is pretty consistent with what you see in an urban market — maybe not at the same rate, but it is just continuously growing.”
GCI is “hyper focused on efficient use of the space segment,” Ayers says, because of the cost of satellite capacity. “In terms of software, we have management tools within our network and planning tools that allows us to efficiently utilize our space segment so that we know where our carriers are, we know where our gaps are, and we can efficiently find carriers ... that are of sufficient size.”
He runs into the problem of either finding adequate platforms available that cost too much, or finding affordable platforms available that can’t deliver the robust service GCI needs. “The reliability of our systems that we deploy quickly becomes a very big issue. When I look at what I'd like to see innovated ... it’s a resurgence of this focus on reliable systems development,” he says. “If we go out and deploy something [within rural Alaska], and it fails, it is often a really big deal. [Limited service] can be catastrophic for a hospital in a rural community that only has satellite connectivity out in their village.”
According to Placido, satellite coding and modulation has consistently improved over the past 30 years to adapt to digital demands, with satellite service providers employing an array of bandwidth management techniques that range from the satellite spectrum level to software-driven functions at the application level.
“From the early days of digital satellite links that used Viterbi/Sequential coding to today´s scenario of links using flexible [Low-Density Parity-Check] LDPC coding or [Digital Video Broadcasting-Satellite second generation extension] DVB-S2X links with higher order modulations (16QAM, 32/65APSK) and sophisticated error correction algorithms, things have improved consistently,” Placido said. Other bandwidth management techniques used concurrently in Fixed Satellite Service (FSS) and HTS service include “carrier canceling, [Time Division Multiple Access] TDMA and dynamic [Single Channel Per Carrier] SCPC access, Adaptive Coding and Modulation (ACM), bandwidth optimization and compression (for cellular backhaul and enterprise data), HTTP/TCP [Hypertext Transfer Protocol/ Transmission Control Protocol] acceleration, edge caching, HTS beam roaming, and smart [network management] systems.”
But developments do not just mean more bits per hertz, Placido warns. They also mean smart ways to manage bandwidth assignments dynamically. For instance, while SCPC technology continue to push the boundaries of bandwidth efficiency by performing carrier cancellation on point-to-point links, TDMA systems have developed substantially to the point that the markets served by either SCPC and TDMA vendors overlap.
“You can think about [bandwidth optimization strategy] in all sort of different ways,” suggests Lucas. “You can put yourself in the management of the portfolio perspective, or the customer quality of experience perspective, or what it means from a technology perspective — [that is] what components and what systems and what devices do you need on the infrastructure to make it all happen in terms of quality of experience management, quality of service configuration management, and moving things around the world.”
Higher Data Rates
Higher data rates, more efficient and effective use of satellite bandwidth and more reliable transponders and service continuity are essential to the exchange of increasing volumes in data, video and voice-over-satellite applications. End-users have also come to expect connectivity anytime they travel, anywhere they live, and everywhere they work.
“Keeping the quality of experience and the reliability and resiliency of the services across that dynamic, highly fluid underlying environment is absolutely utmost in our minds,” said Lucas. “Efficient use of bandwidth, flexible delivery, and reliable quality of user experience have become the three primary principles to ensure economic, affordable, and effective service.”
VT iDirect, for instance, is focusing on performance, efficiency and scalability through more efficient modulation coding (such as 32APSK which is adopted by DVB-S2) and enhanced Forward Error Correction (FEC) rates for data transmission in its Evolution 3.2 system. iDirect has also developed a next-generation network management system called Pulse which is enabled to scale network sites via web-based Application Program Interfaces (APIs).
NovelSat is focused on spectral efficiency and has developed an “echo cancellation” technique that enables uplink and downlink on the same bandwidth, doubling transmission capacity over existing bandwidth. Called DUET CEC (Carrier-Echo-Cancellation), the technology is not a hardware, but rather software-defined radio that can be upgraded over-the-air as a remotely downloadable software module.
DUET CEC transfers data at 850 Mbps in bidirectional traffic over a 84 MHz transponder using NovelSat’s NS3000 satellite modems, processes signals digitally in both directions, and enhances signal efficiency by eliminating degradation associated with “redundant conversion of digital to analog and back.” DUET CEC is also characterized by “close to zero implementation loss (0.2 dB), zero jitter and zero latency” according to NovelSat, making it appropriate for VoIP and real-time video.
With companies around the world wanting higher bandwidth data services, especially for streaming/video services, flexible delivery of video content becomes increasingly relevant in mobile networks, according to Tim Peyla, vice president of business development at Sevis Systems, a backhaul optimization technology company. Sevis plans to deal with the challenge of pre-compressed streaming video by using optimizers with high processing power and storage capabilities to catch mobile computing functions at the "edge" of the hierarchical network to facilitate mobile content delivery.
“I think that the real breakthrough of Sevis backhaul optimization and acceleration is that not only do we empower the satellite backhaul ecosystem via bandwidth-saving products and features, but that we can be considered a key building block towards the expansion of satellite addressable markets,” says Peyla. “As an example, our backhaul offload feature allows satellites to be complementary to existing microwave links, potentially making our technology useful not just in remote or rural locations unserved by terrestrial access, but also in suburban areas where terrestrial backhaul access may be available but inadequate to deal with increasing needs of speeds of data services.”
“Backhaul optimization and acceleration techniques such as those used in enterprise networks and 2G/3G/4G cellular backhaul are also now a key element of bandwidth management,” agrees Placido.
iDirect's Layer 2 over Satellite (L2oS) system, a feature within its Evolution platform, integrates with other telecommunication access technologies in a transparent environment by innovations such as advanced header compression and hybrid (routing/bridging) network capabilities to enable standard Ethernet connections across satellite links.
Maritime applications also see challenges in flexibility. For instance, a cruise ship transits from beam to beam, satellite to satellite, and band to band as it sails across the world. It’s bandwidth management must accommodate that highly fluid environment and support the communication needs of the operational crew as well as the passengers.
“So you can imagine it ramps up the level of sophistication that we need to deploy,” says Lucas, “in an effective way that is high quality, delivers the customers CIR [Committed Information Rate] ... while eliminating the complexity from the customer's world. That would not be possible without us having a very flexible piece of equipment.”
Harris’ CapRock One platform has architecture that includes satellite, wireless, and terrestrial transport technologies, which can automatically adopt its transmission medium based on speed, latency, location, and cost, without human intervention.
Role of Satellites
According to Placido, access to satellite bandwidth itself is not a technical challenge. Instead the challenge is reaching the right economic points for such bandwidth to be useful and making use of smart bandwidth management strategies to maximize value.
“It is time for the satellite industry to re-explore the strategic role that satellites could play within the evolution of the telecom and entertainment sectors. I think it is time to re-explore the roles of satellites in fixed and mobile content delivery as this relates to three key markets served by satellite networks: Satellite HTS broadband, cellular backhaul, and video distribution.”
Lucas also notes that users to have little tolerance for service interruption and expect less and less errors in the system. “An important part of the technology going forward is to ensure that this highly fluid, relatively chaotic environment is managed to the appropriate high standards and paired to the individual's expectation and the customer's business expectations.”
Effect of HTS and Small Satellites
The advent of HTS and proliferation of smaller satellites in LEO and MEO has had a reverberating effect felt in every corner of the telecommunications market. Wulkan believes that in the 2020s the majority of traffic will be over LEO satellites, not over GEO.”
“Some may think that satcom’s transition to HTS, with larger supply figures and lower bandwidth costs could undermine the importance of bandwidth management,” said Placido. “I frankly think that it will be just the opposite. Bandwidth management is and will remain important, and possibly even more in the context of GEO-HTS and LEO-HTS.”
"With HTS, [bandwidth management] becomes a little more complicated because ... all of a sudden you have a satellite that has 50, 80, or 100 spot beams and you might even have two or three more satellites that are offering all that bandwidth," agrees Mike Patullo, Systems Engineer of intelligent payloads with iDirect.
According to Wulkan, video has also indelibly changed the market, and the future may hold 40 terabit per second data rates as early as 2020. “Even if you take that with a grain of salt,” said Wulkan, “For data communication purposes it will be more significant than the whole [current] satellite industry.”
“You can see [market predictions] for companies looking to actually eliminate cellular networks and use satellite hotspots with handset communicating directly with the LEO satellites ... even if you discount some of the [predictions], we are the verge of a huge revolution.”
In the terms of bandwidth optimization in backhaul, Peyla expresses concerns that technology has yet to harness the full potential of the new space market.
“We are not yet leveraging one key aspect that defines satellite communications: their one-to-many broadcast economics,” says Peyla. “We think that using satellites’ IP multicast advantages for content distribution will be key in the future, so we are closely monitoring developments in the field of mobile content delivery to time our developments right.”
“Having approached the limits of spectral efficiencies at the [radio frequency] layer, the industry will inevitably pay more attention to application-aware bandwidth optimization technologies. New optimization and acceleration technologies may come from expert players in the different fields,” says Placido. VS