IP and Satellite: Communication Worlds Merging
Every revolution has a defining moment, and in the modern world of telecommunications there may be none more important than the development of Internet Protocol (IP). Even with its early shortcomings, IP solved ongoing conundrums of interconnectivity, driving everyone in the same direction, and international standards committees have included new capabilities in their specifications that allowed both terrestrial and satellite service providers to play to their strength.
“The advent of IP brought everything together,” says David Bettinger, CTO for iDirect. “It makes it possible to run different applications — voice, video and data — all on the same network, and this carries important advantages for service providers because there is only one network to manage and provide training for. From the consumer’s point of view, there is only one vendor and one bill to pay, so the benefits are really across the board. Terrestrial carriers led the way, taking advantage of the benefits of Multi-Protocol Label Switching (MPLS), in which a label is attached to every IP packet. This makes the delivery process faster because the router doesn’t need to look up the packet’s destination. Label switching makes it possible for legacy applications to run on IP networks. Today, satellite carriers are following suit and providing support for the same applications.”
The addition of IP to the hybrid world means that even more, a satellite-only network is a thing of the past, says Bettinger, “In reality, every satellite network is now a hybrid. A satellite terminal is either used as an edge connection or as the middle-mile approach with terrestrial circuits on either end. Satellite networks almost always terminate back into a terrestrial network. For example, teleport operators provide private backhaul circuits to a company’s headquarters where the traffic is deposited into the company’s core MPLS network and routed accordingly.”
The road to hybridization has been a long one with changes taking the better part of two decades to fully germinate, but corporations, governments and militaries are reaping the rewards of hybridization today. When Hughes began offering shared hub services, the satellite operator had to provide terrestrial bandwidth, says Mike Cook, senior vice president at Hughes Network Systems. “We took a step back three to four years ago and took a hard look at our business. We are really a managed service provider, not just a transport provider. When you break that mindset we realized that we can provide additional services to our clients.
For BP Corp.’s retail point-of-sale network, which involves two hubs, two satellites and multiple backhauls to and from different data centers as well as suppliers and end users, Hughes installed and manages both DSL and satellite broadband technologies at more than 10,000 retail locations. The fully integrated, managed broadband network includes the migration of the network to IP, supporting new point-of-sale systems, and providing a platform for the delivery of potential future bandwidth-intensive applications. “This is very powerful from our customer’s point of view,” says Cook. “Unless they use a managed service provider, the customer would have to sign and manage multiple carrier contracts. They can now deal with a single managed service provider. We have automated provisioning and trouble ticketing systems and provide comprehensive managed services. Our approach allows us to optimize a client’s network several different ways,” he says.
“IP is here and it has transformed the way things are done,” says Bettinger. “We now have the benefit of advanced [quality of service] across the satellite link. In addition, MPLS and advanced routing protocols have had a big impact. The retail industry is a good example of what is happening with hybrid networks. Retailers started with terrestrial but then transitioned to VSAT to get more bandwidth. They are discovering that satellite technology has some powerful benefits in an IP-based world and are finding new ways to utilize satellite systems.
Not Really New
IP gear for satellite data communications is not new, nor is video-over-IP technology. Enterprise video networks have employed IP since the late 1990s, and the technology has been used in satellite Internet backbone connectivity links, corporate VSAT and consumer applications with huge benefits in terms of cost savings and network flexibility. In television today, non-real-time video delivery applications from video-on-demand content to spot and syndicated program distribution to news clips all take advantage of IP networking. For real-time television transmission, delivery of video over IP transport has not been the standard. Key reasons include the technical challenges in assuring MPEG picture quality over IP links in general, but that is changing. Satellite video equipment manufacturers’ current and next-generation products are already playing in an IP-networked world, and IP is becoming mainstream in real-time satellite video according to hardware players.
One area equipment providers see growing is IP multiplexing in the direct-to-home (DTH) satellite headend and the potential for remote encoding and multiplexing of contribution signals over terrestrial IP networks feeding the DTH uplink. According to Are Olafsen, director of satellite headend solutions with Thomson, “By adopting IP technology in the broadcasting industry, DTH satellite operators can gain increased flexibility to design their headend architecture and realign services at any point during the lifecycle of the system.”
The DVB-ASI (DVB asynchronous serial interface) protocol tends to be the protocol of choice for satellite video connections, but IP offers some advantages over ASI such as greater capacity and network flexibility. IP/Gigabet Ethernet network capacity is about 950 megabits per second (Mbps), compared to about 270 Mbps for an ASI connection. IP/Ethernet networks can be simpler to install, manage and maintain. For example, channel lineup changes are transparent to an IP/Ethernet network. IP equipment is used universally for networking, unlike DVB-ASI, which is limited to the broadcast and satellite world. Gigabit Ethernet Network Interface Cards are cheaper than their ASI equivalents. IP technology also allows for a geographically distributed encoding architecture.
Tandberg Television has been deploying IPTV headend systems at DTH centers around the globe. In 2007, Bharti Telemedia, a subsidiary of Bharti Airtel Ltd., chose Tandberg’s advanced IP headend for the launch of a new DTH satellite TV service in India. The solution chosen by DirecTV for its local high-definition (HD) expansion also includes Tandberg’s newly-released EN8095 encoders, part of the EN8090 MPEG-4 AVC SD/HD encoding family, which includes IP statistical multiplexing. And recently, Tandberg announced that its MPEG-4 AVC compression and IP multiplexing solutions are being used in Europe by Telenor Satellite Broadcasting to provide IP video contribution and direct-to-consumer IPTV services in Scandinavia. Telenor’s system involves remote encoding and multiplexing from six locations across Northern Europe and Scandinavia. Telenor encodes video at various source points for delivery over an all-IP transport network using the EN8030 MPEG-4 AVC encoders and MX8400 IP multiplexers.
Low Latency MPEG-4/AVC Research Pays Off
Technologies continue to advance at a rapid pace as HD and IPTV services roll out to consumers in markets around the world. To maintain and grow market share, equipment providers need to continually invest in new features, product development and technologies. Encoder manufacturers are putting significant investments into MPEG-4/AVC, including hardware and ASIC chip development and improvements and software to improve latency, processing speed and picture quality at ever-reduced bit rates. “Thomson has been investing heavy in new technologies to deliver the added value to our customers,” says Olafsen. Thomson has about 600 research and development engineers in seven labs around the globe. The networking focus area includes developing advanced IP solutions for optimized content delivery. The company also is building its third generation of MPEG-4 set-top boxes.
Another area of research and development that is starting to pay off for equipment manufacturers is in software development for MPEG-4/AVC compression. One barrier to commercial adoption of MPEG-4/AVC in satellite newsgathering applications — despite the potential for 40 percent to 60 percent bandwidth efficiency gains compared to MPEG-2 — has been the additional processing time (latency) MPEG-4/AVC has added to links. Encoder latency with MPEG-2 is commonly available at less then two-tenths of a second for standard-definition video and less than half-a-second for HD. Until recently, with MPEG-4/AVC encoder products on the market, latency could range from more than half-a-second to a full second for HD. Adding that to the existing half-second delay of a satellite link made real-time interactive applications like live news interviews unlikely.
Fujitsu Computer Products of America Inc. has reduced encoder/decoder latency with MPEG-4/AVC to 300 milliseconds, so live interviews could be conducted with acceptable HD picture quality while using less than half the network bandwidth required for MPEG-2 transmissions. Fujitsu entered the U.S. broadcast and satellite newsgathering encoder market in 2007, focusing on MPEG-4 AVC products built for transmission over IP networks. Earlier this year, the company made inroads with CBS News, which announced it would use IP9500 for satellite newsgathering as well as remote interactive news feeds.
“In Japan, Europe and Asia, many feeds are being managed exclusively through IP-based transport. In the United States, we have seen a significant increase in the last three to five years in IP-based transport,” says Dan Dalton, director of new product development at Fujitsu. “The IP market for broadcast solutions is growing rapidly, especially in satellite and terrestrial markets. There is still a large amount of satellite bandwidth that is available for such solutions,” he adds.
Scopus Video Networks Ltd. is another equipment manufacturer seeing steady growth in IP requirements from its customers. “In the last few years, a lot of what we sell has either IP input or IP output or both,” says Gal Garniek, associate vice president for marketing, who estimates about 30 percent of orders include IP options and about a 10 percent growth yearly for IP interfaces on products. “Currently, more encoders are shipping with with IP in/out than IRDs, but I think in the next few years IRDs will be selling more with IP outputs.”
More IP Boxes
Manufacturers’ representatives and systems integrators say more IP-ready gear is being ordered with satellite video systems. Fred Pope, president of Satcom Resources, a global distributor and integrator of satellite communications equipment, says. “The move to MPEG-4 and HD is providing very cost effective upgrades for our operators, improving bandwidth as much as 50 percent and MPEG-4 is typically over an IP transport. For IP gear, we are seeing a lot of IP over DVB-S2. More and more equipment is being used to stuff IP traffic over DVB transport, as opposed to serial data. Although there are still a lot of traditional video encoder-to-decoder configurations, IP inputs and outputs are becoming more prevalent. Of the DVB modulators and demodulators we’re selling now, more and more have an IP interface than a serial interface or an ASI interface,” he says.
Sean Busby, executive vice president of TBC Integration, a system integrator for MPEG-4/AVC and DVB-S2 solutions and distributor of satellite video network equipment, also sees IP features shipping more. Positioning to ride the wave, TBC Integration Inc. formed a separate software division, DigitalGlue, which helps broadcasters and manufacturers create better user interfaces and GUIs to move their IP content. A common challenge we see within broadcast organizations is determining who is responsible for this IP traffic. Is it the broadcast engineers or the IT department? Most organizations have their IT department purchase and configure the routers and VLANs. Broadcast engineering may then ask IT to step away after a network has been set up, while IT views its mission as ongoing management of the IP network. If the demarcation of responsibilities is not clear when systems are set up, it can also prove troublesome when it comes time to identify the sources of network faults on an IP network that could be causing impact on live video traffic,” he says.
Embracing The Future of IP
Whatever the challenges, satellite video equipment vendors are embracing IP network architectures. Before long, it may be hard to imagine satellite video equipment without IP connections, and it is being driven by the same advantages and capabilities IP networking brings to communications LANs and WANs — cost, traffic flexibility and interoperability, plus the availability of reliable IP transport services. The good news for users is IP can mean more choice and flexibility to choose satellite communications networks and more flexibility to select among a wider variety of satellite bandwidth options.