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Advances Keep VSATs Relevant in Changing Market

By | September 1, 2010

      A quarter century has passed since Wal-Mart rolled out its M/A-COM (later acquired by Hughes) Ku-band VSAT network. The innovative technology allowed the retailer to displace a terrestrial network made up of leased analog circuits from more than 400 telephone companies. More importantly, the network allowed the Bentonville-based retailer to scan their inventory once a day — something unheard of at the time — and helped them overtake K-Mart and Sears to become the largest retailer in the land.

      Based on Wal-Mart’s success, VSAT quickly became the de facto standard for retail networks, with point-of-sale and lottery networks becoming the mainstay of the VSAT industry. The retail industry still relies heavily on VSAT technology causing one to ask: Are VSATs relevant outside the retail industry? Are they relevant in today’s enterprise networks? 


      Because of their success in the retail sector, VSAT providers often suffer the same fate as do character actors: while very good at what they do, they are relegated to play a few, limited roles. Much has changed over the years and VSAT technology is anything but a bit player.

      Dave Rehbehn, senior director, marketing, International Division at Hughes, provides some scope regarding how much the VSAT market has grown. “The development of the Internet and IP protocol support created huge demand for bandwidth, and VSAT is the right technology for hard-to-serve areas. To date, Hughes has shipped more than 2.2 million terminals, and we are rolling out more than 300,000 new terminals a year. We are delivering broadband service to more than 500,000 consumer subscribers in North America. Beyond the United States, the broadband trend is continuing, with many governments using satellite to provide a range of services to citizens in underserved areas, often funded from their Universal Service Funds. These large projects are driven by the desire to connect to the Internet. Our volume production, along with continuing advancements in silicon and gallium arsenide, enable us to make our terminals cost-effective and therefore attractive from a capex perspective. We have also focused on lowering operating expenses through the implementation of such advances as DVB-S2/ACM on the forward channel and IDPC coding for the return channel”

      Glenn Katz, president and COO of Spacenet contrasts the company’s current services with those it offered in the past. “We support much higher speeds these days. In the beginning, inbound channels were only 19.2 Kbps (kilobits per second). Today we support outbound circuit speeds up to 8 Mbps (megabits per second) and inbound speeds to 2 Mbps,” he says. Katz also noted the company’s adoption of the DVB-S2 standard for outbound traffic.: “Our advanced encoding algorithms allow us to send higher number of bits per megahertz of bandwidth. The cost per bit has come way down and will continue to go down, making the cost of satellite service more cost effective. Once we reached higher circuit speeds, we began to support higher speed applications, which, in turn, drove us to develop more sophisticated and embedded routing protocols, such as BGP, which is important in the big box retail and financial markets. We have also made big advancements in application acceleration to insure a good user experience,” he says

      Daniel Enns, senior vice president marketing and business development at Comtech EF Data, says, “Several key enabling technologies should be credited for the growth in the satellite industry,” Enns said. “Spot beams allow frequency reuse and are critical for the new generation of broadband satellites. In addition, advanced forward error correction and modulation schemes have helped dramatically improve the spectral density, thereby lowering latency and the cost- per-bit efficiency and, hence, reduce the cost per bit or improve the throughput

      Dave Bettinger, CTO of iDirect, points to the move to IP-based applications as a hallmark event in the development of VSAT as a mainstream network technology. “Customers don’t care that their data is on a satellite network. They are worried about management of their network and security. They simply want to plug in an Ethernet cable and have their applications work. In the past, we used to sell to satellite engineers. Now we are calling on CIOs.”

      George Head, Stratos senior vice president, Broadband Services, echoes Bettinger’s comments, stating: “From a customer perspective, VSAT is now part of a solution matrix. Our customers use VSATs as an extension of their corporate network. Their employees may be remote, but they have an expectation that the connection will work well and work fast. “

      Second Cousins; Once Removed

      SCPC and TDMA have served as the vanilla and chocolate of the satellite data world for the last 25 years. Both are good, and up until now, choosing one meant the exclusion of the other. As satellite modems become more powerful, they are able to morph themselves into hybrid networks employing the best characteristics of both SCPC and TDMA. “We have bifurcated into two camps over the years: TDMA or SCPC,” says Bettinger. “Large trunking applications are clearly SCPC applications, but large file transfers and videoconferencing, while ideal for SCPC, are hard to predict, making them very inefficient if you reserve SCPC channels just for those applications. We hope to break down the barriers between SCPC and TDMA in the future,” he says.

      “Cellular backhaul traffic is very symmetrical,” says Enns. “Nothing is sharable at peak hour. Voice traffic is very deterministic, and we know that fixed capacity is required to provide quality voice service to cellular subscribers. Jitter and latency are significant issues in voice networks since voice packets can’t be buffered and delivered at a later time. But in some hub and spoke applications, it makes sense to share the outbound carrier among multiple terminals rather than putting up multiple outbound SCPC circuits. Our new Advanced VSAT Series uses a DVB-S2 shared outbound carrier and multiple SCPC carriers. The inbound carriers are configured for VersaFEC, which is ideally suited for cellular backhaul due to its low latency while providing excellent coding performance. This approach is extremely efficient and provides the cellular carrier the dedicated bandwidth while taking advantage of the multiplexed outbound carrier.” 

      New Applications

      Due to their ability to provide cost-effective services across large land masses, combined with features such as multicast, it is not surprising that VSAT remains a popular networking choice among retailers. While the dish on the roof has not changed, the applications inside the store and the services delivered have. Driven by customer demand, Hughes and Spacenet both have broadened their business scope and now provide fully managed network services, including terrestrial services. “In the old days, we were selling VSATs against everything else,” Rehbehn says. “We made the shift several years ago and now sell managed services. DSL is not a networking technology, it is a transport technology. Someone has to manage all of the circuits to monitor whether the circuits are up and running and if the circuits are running well. On top of the management duties, someone has to be concerned with network security.”

      Katz points out that satellite still has advantages, such as being able to multicast files — such as virus updates — to thousands of stores but agreed that terrestrial services make more sense when bandwidth exceeds a certain point. “At some point, generally around 1 Mbps, Ku-band VSAT becomes uneconomical, unless there isn’t an alternative,” he says. “Big box retail stores are like big islands, and they can’t afford to lose their network connectivity. We were being pushed to provide 100 percent connectivity. VSAT is now counted on to provide business continuity in the event a terrestrial connection fails.”

      Prysm Pro is a network appliance that Spacenet builds which manages the different telecom connections at a remote location. There was a need for some sort of appliance to manage these various connections and reroute the traffic in the event of a link failure, and Prysm Pro allows Spacenet to mix and match any combination of telco connections. “In one of our networks we use 3G wireless to back up DSL lines,” Katz says. “With the advent of broadband, PCI (payment card industry) compliance is a major issue with retailers. If you aren’t PCI complaint, credit card processors won’t process your data. There are strict compliance measures and Prysm Pro helps defend the edge of the network against attack.”

      All of the vendors view communications on the move (COTM) as the application with the greatest growth potential in the near term. “We are seeing tremendous interest in mobility applications,” says Rehbehn. “Everything we used to do was fixed, but now we are providing military and maritime COTM applications. Another exciting program we are working is the Row 44 Service for Southwest Airlines. They will be using our satellite systems to provide in-flight Internet services to their customers.”

      From crew boats to drilling rigs to ocean going vessels, Stratos has been providing COTM applications to clients in the energy and maritime markets. Head sees the demand increasing in these markets. “End users require bandwidth in remote locations to do their jobs. They expect connections to the corporate network even though they may be many miles out in the ocean. Stratos works with multiple hardware vendors, allowing us to field a best-of-breed solution. In addition to their everyday work activities, we are seeing telecommunications as an important part of employee retention in the maritime industry,” he says.

      “Due to the limited number of subscribers compared to metropolitan areas, rural telephony often requires government subsidies,” says Enns. “However, many universal service obligation (USO) opportunities can actually be very profitable ventures if the carrier adopts the pre-paid minute model. Instead of having the people in a remote village pay a monthly subscription, services are pre-paid by relatives living in the large cities. Generally, these are sons and daughters who will buy their parents a phone and then send them pre-paid minutes so they can make outbound calls. If the wireless carrier puts the right program in place and deploys the best delivery technology, then there are potential good profit opportunities.” 

      Mitigating Interference

      One of the only drawbacks to increased VSAT network usage increases around the globe is a parallel increase in incidents of radio frequency interference, which can disrupt data transmissions and other critical communications services, hindering business growth. The highest rate of interference occurs in fast-growth regions such as Africa and the Middle East, and throughout such regions, there is an ongoing challenge to help VSAT users understand how incorrect installation — substandard antenna assembly, mispointing, cross pole and poor line-of-sight considerations — can lead to interference.

      To promote an interference-free space environment, 19 satellite operators and industry associations such as the Satellite User Interference Reduction Group and the Global VSAT Forum have joined forces to reduce interference on a global level. In 2009, Intelsat launched the Intelsat Interference Management Initiative to increase awareness throughout the end user community and lead an effort to ensure technicians obtain proper training, increase the quality of data and communications regarding interference events and guarantee proper alerts are implemented to reduce reaction times when interference occurs.

      The first step toward maintaining an interference-free space environment is to provide training for the user community. Operator’s are sponsoring training sessions of the Global VSAT Forum’s online training program which educates technicians on proper equipment installation and operational parameters of VSAT networks. Rodrigo Chagas, an installer with Telespazio Brasil, says the training was useful in helping young technicians grow within the telecom sector. “There were some [interference] concepts of which I was not aware until I completed the online coursework. The training definitely helped me become more effective when troubleshooting [interference] cases.” 

      All in a Name

      Perhaps the term VSAT is the industry’s worst enemy. Very small aperture terminal stresses antenna size, not what the device can do. Imagine Cisco’s success if they had named their product “small metal box with blinking lights”. In a sign of the times, Hughes has begun referring to their products as satellite routers. “Our products are very IP-centric,” says Rehbehn. “We looked over all of the IETF [request for comments) for features and functionality and can count over 50 that we support. We are constantly striving to improve the performance of our routers. We now support a satellite router that works on a terrestrial link.”

      Likewise, Spacenet has embraced routers in a big way. Working with Cisco, Spacenet developed several years ago a plug-in module which goes inside a Cisco router. In the event the terrestrial connection fails, the traffic fails over to the satellite connection. Katz notes Spacenet’s development of advanced routing protocols, such as BGP and VRRP (virtual router redundancy protocol). The latter allows two routers to reside on the same remote network and to back each other up if one fails.

      These advanced routing protocols allow network engineers to incorporate VSATs into their terrestrial networks and use the features and functionality they are familiar with. A good example of network integration between VSAT and terrestrial networks are the iDirect networks deployed by Verizon, BT, and Orange. iDirect’s support of MPLS allows traffic to be routed seamlessly across the carriers’ MPLS network.

      While retail point of sale and lottery networks have not gone away, they are not the only applications which are well suited for VSATs anymore. Cellular backhaul, mobility, business continuity, and Internet access will continue to fuel the market for satellite communications, making VSATs relevant for many years to come.

      Greg Berlocher has been active in the satellite industry for twenty five years and is the President of
      Transcendent Global Networks LLC.