Video for the Long Haul: Exploring Backhaul Options

You’re streaming a high-profile event in the not-too-distant future, and you’re wondering about your options for transmitting your video to your streaming server or service provider. You’re concerned about quality, reliability, and perhaps redundancy. You’ve read about satellite and fiber, as well as multiple options for efficiently transmitting over IP networks, but you’re not sure what they require in terms of equipment and cost. If this in any way describes your situation, you’ve come to the right place, because these backhaul options are precisely what I’ll be covering in this article.

Let’s start with some assumptions. First, you won’t be encoding the streams you’ll actually distribute onsite. Instead, you’ll be sending the signal elsewhere for encoding, either in the cloud via live cloud transcoding or to a remote facility with a bank of hardware encoders that can produce multiple Flash and HLS streams. Second, your primary interest is streaming, not broadcast. So the goal is delivering a reliable 4-8Mbps 1080p stream to your encoding facility, not a broadcast-quality signal.

If you asked large event producers to choose a transport technology even two or three years ago, fiber and satellite would likely have been first and second on most lists. Today, however, the availability of live cloud transcoding, the maturation of internet connectivity at hotel and conference centers, and the availability of tools that enhance IP transport all come together to push fiber and satellite to the rear for many producers.

For example, Mark East, iStreamPlanet’s executive director of live event operations, says his preferred transport method for many live events changed to IP transport when iStreamPlanet launched its Aventus live video workflow platform, which includes live cloud transcoding. Before Aventus, he would have to route the live signal to one of the company’s broadcast operation centers to encode the stream into the multiple formats and variants necessary for most clients. Though costly, this is the high-bandwidth routing that satellite and fiber are designed to accomplish.

Now, if he can deliver one high quality stream at 3-5Mbps to the Aventus server in the cloud (Figure 1), East says he can producde the same viewer experience at a fraction of the cost. If your workflow involves live cloud transcoding, say with the Wowza Transcoder or a service provider like Brightcove, YouTube Live, or Aventus, you should explore IP transport techniques first.

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Figure 1. The live cloud transcoding feature in iStreamPlanet’s Aventus service makes IP delivery the preferred technique.

Will There Be Ethernet?

While sourcing bandwidth from a hotel or conference center used to be problematic, things have changed.

“Most of these internet services are now managed by third-party service providers who worked the kinks out years ago,” East says. “It’s been a while since we had an unrecoverable issue with bandwidth sourced from a hotel or conference center.” However, East strongly recommends obtaining dedicated bandwidth rather than broadcasting via a shared connection.

For high-profile events, East advises having a representative from the hotel or conference center on site or on call to swiftly resolve any issues. He also recommends producing two outgoing streams for redundancy, each pointed to a different CDN data center. That way, if a hop between you and one CDN data center goes down, or if the data center itself goes offline, the CDN’s back-end can automatically switch to the backup stream and the show will go on.

Of course, for true outbound bandwidth redundancy, your backup signal needs to use a different medium than your primary. In this case, you might consider using a 4G cellular multiplexing, or cellmux, device, discussed next. These are also your least expensive options when your broadcast point doesn’t offer Ethernet but does have 4G/LTE connectivity.

4G/LTE Cellmuxers

A typical scenario for cellmux devices might be a broadcast from a company off-site event, or a sporting event where Ethernet isn’t available but one or more cellular towers are closeby. While you can use a single 4G modem with most on-camera encoders, this enables a single connection only, and no redundancy, which is why cellmuxes are preferred.

As the name suggests, a cellmux can use multiple modems connecting via multiple 3G and 4G services to provide a higher bandwidth and built-in redundancy. For instance, if you’re in a Verizon dead zone, ATT might have a signal. If the Sprint circuits get clogged with other traffic, perhaps it’s T-Mobile to the rescue. Some devices, such as the LiveU LU70, can deploy up to 14 cellular modems, while less expensive models from companies like Teradek and LiveGear use six or fewer, which should be more than enough for a 3-5Mbps stream. When other signals are available, some units can also integrate Wi-Fi, WiMAX, Ethernet, or even satellite connectivity into the mix to enhance both throughput and signal redundancy.

Most cellmux units either incorporate an H.264 encoder or work with a sister product that provides these encoding functions. You plug the HD-SDI output from your camera or mixer into the unit (or combined units), which encodes your video, divides it up into chunks to distribute via the different connections and sends these chunks on their way (Figure 2). 

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Figure 2. The two sides of the cellmux solution, shown here in LiveU’s configuration.

At the other end, these chunks need to be reassembled into a cohesive stream. If you’re transcoding in the cloud, most cellmux providers offer a cloud-based service or server, like Teradek’s Sputnik, that can de-mux the stream and send it to your server. If you’re using a standalone hardware encoder, cellmux providers typically offer decoder hardware, such as the LiveGear LGR-1000 receiver, that can demux the stream and output an HD-SDI signal to feed into your encoder.

Either way, to use cellmux technology, you need to figure out both the encode and decode sides of the equation. So you need to buy the cellmux and any required modems, sign up with the various cellular providers, and figure out what you need on the back end to decode the stream. For occasional use, you may be better off leasing the entire package from the manufacturer or a third-party service provider. 

Beyond simple H.264 encoding, these cellmux systems offer advanced techniques such as adaptive bitrate encoding, which matches the bitrate to the available bandwidth, and forward error correction to minimize error in the signal. One competitive and complementary technology that’s gaining widespread acceptance is Zixi, which provides an enhanced quality of service layer over the H.264 stream to reduce latency, jitter, and packet loss. You can use Zixi to solve the first-mile problem of getting your video into the cloud over IP-based technologies, or deploy it throughout the entire encoding and delivery workflow. While it might not be appropriate for a one-off event, it should be on your radar screen for more regular events.

Meet Zixi

Implementing Zixi involves three components: Zixi Feeder, Zixi Broadcaster, and Zixi Receiver. Zixi Feeder wraps the H.264 encoded stream in the Zixi format and delivers it to Broadcaster. Feeder is available as either a standalone program running on a computer or as a feature in other companies’ encoders. Broadcaster, which can run on premises or in the cloud, can push the stream to your streaming server or transcode the incoming stream into multiple HLS, HDS, or DASH streams for delivery to your CDN.

Like Feeder, Receiver can run as a component of a decoder product, with both Ateme and Teradek offering Receiver in several of their products, or on a separate computer with the appropriate output card. Receiver’s job is to unwrap the Zixi transport layer and deliver it either to the decoder card, say for HD-SDI output, or as a standalone MPEG transport stream for transcoding or other deployment.

Zizi’s pricing depends upon how and where you acquire the separate components. For example, with the Teradek Cube, Zixi costs $1,000 annually. JVC, which is including Zixi in its new ProHD Broadcaster option for several of its new cameras, will charge $1,995 for the service (and necessary hardware) plus a monthly subscription. Charges for the Broadcaster component depend upon a number of factors; contact Zixi for more details regarding pricing.

Satellite

For the most part, the solutions we’ve discussed have required IP transport, either via Ethernet or 4G. What are your options when this isn’t available, or when you want to supplement IP transport with another medium for complete redundancy? This is a situation which Corey Behnke, head of global production & services at Livestream, faces frequently, particularly in New York City, where Livestream produces and distributes many live events (Figure 3). In these instances, Behnke typically turns to satellite, beaming up the signal from the broadcast location and routing it back to Livestream’s Manhattan offices for encoding.

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Figure 3. Livestream encodes many live events a year in its Manhattan headquarters, many sourced via satellite or fiber.

There are three types of satellites used for live streaming or broadcast applications: C-Band, Ku band, and Ka band. The first two, C-Band and Ku band, are traditional broadcast technologies, designed, in essence, to input the HD-SDI signal from the source location and deliver that to the output location via satellite. For example, your roving reporter with a satellite truck uplinks the video signal to the satellite, which is downlinked via those huge dishes at the local TV station. In most instances, the output from that signal will be an HD-SDI feed that can be input into traditional broadcast equipment, or, in the case of Livestream, into a real-time encoder.

In contrast, Ka band is an IP-based system. You encode your stream on location, beam that up to the satellite, and the satellite service downlinks the signal and can transmit it directly to your streaming server via the Internet. Though the 10Mbps signal bandwidth is lower than C-Band or Ku band, it’s more than sufficient for a high-quality 720p or even 1080p stream.

Chances are an established provider such as Livestream use Ku band satellite, as opposed to Ka band, because they have the infrastructure in place. Livestream uses a satellite facility owned by All Mobile Video in New Jersey for its satellite downlinks and maintains a fiber connection between the downlink facility and its Manhattan headquarters. This is both efficient and affordable when producing multiple events around the country, but would be cost prohibitive on a one-off basis.

So if you’re thinking about satellite for a one-off event, Ka band is the natural first choice. According to Lenny Laxer from All Mobile Video, you can rent a Ka band truck, with an operator, for around $2,000 for a 10 hour day, which is the minimum rental period. The truck includes all necessary equipment, and upload bandwidth costs $400 an hour. When budgeting, note that Behnke recommends testing the stream a few hours before the event, and then going online about an hour before the event to ensure connectivity. He also advises that when booking the satellite time, you should reserve 15 to 30 minutes of time at the end of the program in case the event runs over. Without this reservation, there’s no guarantee that the satellite time will be available if the show does go long.

Note that All Mobile Video resells the QuickSPOT satellite service (Figure 4) from On Call Communications . For occasional use, renting from a provider like All Mobile Video is probably the best option. For more frequent use, you can buy an antenna directly from On Call Communications.

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Figure 4. The QuickSTOP satellite transmitter: the ultimate SUV accessory.

As with all satellites, you’ll need line of sight between the antenna and the satellite, which can be a problem if you’re in a valley or in midtown Manhattan. However, there are fewer Ka band satellites than either Ku or C-band, so if Ka isn’t available, you may have to use Ku or C-band. In particular, both Ka and Ku are susceptible to rain fade, or poor performance in rainy weather, which might leave C-band as your only alternative.

As mentioned above, with Ku and C-band, you have to plan for both uplink and downlink. According to Laxer, C-band trucks, which use a much larger antenna, cost $4,500 per day for the uplink truck and $3,500 for the downlink truck, if necessary. In addition, if broadcasting from a new location, you’ll have to survey both sites to make sure you have line of site; that costs $500 each. Since C-band can interfere with aircraft, you may have to order an RFI survey to ensure that your transmission won’t; this costs $700. This is in addition to uplink charges of between $200 – $600 per hour depending upon bandwidth, plus downlink charges of around $200/hour.

Ku band trucks cost $3,500 for uplink and $2,500 for downlink, with the same survey charges for line of sight, but no survey fee for aircraft interference. Uplink and downlink charges are about the same. With both bands, if your content needs to be secured, tack on another $500 for BISS encryption and $200 for decryption. If you’re considering satellite transmission, East recommends checking several options, since pricing can vary greatly among the different service providers.

What About Fiber?

Perhaps the most secure method of transmitting video is via fiber, which can carry a signal as high as 1.5Gbps. The only major issue is availability, and perhaps cost.

To get the skinny on fiber, I spoke with Derek Anderson, senior product director for Level 3’s Vyvx (pronounced Vi-vix) business unit. Briefly, Vyvx is a portfolio of products and services, all involving video distribution over fiber (Figure 5). Most relevant to our discussion is the broadcast fiber component, which lets you transmit compressed or uncompressed video from your venue to any destination also connected with fiber. Though the service is available for full-time use, such as the permanent fiber connection discussed above between Livestream’s Manhattan office and All Mobile Video’s satellite farm in New Jersey, you can also deploy the service on a one-off basis.

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Figure 5. Level 3’s Vyvx Network Operations Center runs 24 hours a day.

According to Anderson, Level 3 has fiber it can use in “hundreds of high-use locations and venues.” In these instances, you can book the service just days in advance. Otherwise, if there is no existing fiber connection, Level 3 can install one, either directly or via another fiber provider, but that adds to both lead time and potentially cost.

To use the service, connect the output from your camera or switcher to a rack-mounted appliance, typically called a codec, that Level 3 supplies. Level 3 encapsulates the signal before it hits the fiber, then transfers those packets across its global network to the destination point, where it’s unencapsulated and output from a second codec into a broadcast switcher or encoder. Alternatively, Level 3 can route it directly to your streaming server for transcoding, or transcode it for you and deliver the streams to your CDN, or serve as your CDN.

Compared to satellite, fiber has fewer moving parts, no line of sight requirements or surveys, no trucks, and no bad weather to worry about. Compared to IP solutions that use the general internet, working within a managed network should avoid the packet loss and jitter that sometimes results from the multiple hops endemic to the internet. It’s the closest thing to a direct cable connection between your source and destination locations.

Level 3 is generally mum on pricing, which in any case depends on the duration and bandwidth of the broadcast, as well as whether fiber is already available on site or needs to be installed. Their only statement was that “basic fiber services are generally comparable in price to satellite,” while pointing out that fiber offers multiple value-adds that satellite doesn’t provide, like high-speed data and telephony.

iStreamPlanet’s Mark East says the last time he used Vyvx, the occasional use fees were a bit pricier than satellite transmission charges, but noted that the added costs of site surveys, truck rental, downlink, and other satellite-related charges often tip the scales in fiber’s favor, unless you have to pay to get the fiber installed. Behnke says there are likely cheaper alternatives to Level 3, including The Switch, Hibernia Networks, and Encompass. He also noted that while he’s only used Vyvx a handful of times because it’s not generally available from his broadcast locations, it worked very well when he had access to it.

Even with a fiber connection in place, don’t forget about redundancy. As All Mobile Video’s Lenny Laxer points out, “if a backhoe comes through at the wrong time, you’re toast.” For the high-profile events that his clients produce, like the U.S. Open Tennis Tournament, Laxer recommends fiber for the primary signal and satellite for the backup.

To summarize, if you’re pointing your stream towards a server in the cloud, as in the iStreamPlanet Aventus workflow, consider IP transport mechanisms first, whether simple Ethernet, cellmux, fiber, or Ka satellite. If your final target is an HD-SDI signal you can input into a standalone encoder, the typical Livestream workflow, consider fiber first, as the easier to implement solution (when available), then Ku/C-band satellite. Irrespective of your target, the best backhaul option for you depends upon factors like availability and cost, and you should always check with multiple providers to make sure you’re getting the best price.

About Jan Ozer

I help companies train new technical hires in streaming media-related positions; I also help companies optimize their codec selections and encoding stacks, and evaluate new encoders and codecs.

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