Sports production has driven much of the advanced video networking we see today. Live sporting broadcasts — with their highlight packages, clips and slow motion — have pushed higher-bit-rate production, low latency, greater mobility and higher-speed workflows. Viewer demand for a true HD experience on all connected devices only adds to the demands placed on video infrastructures. Networks of today are fundamentally evolving from point-to-point infrastructures to dynamic, multiservice networks that can provide content to all screens with the same speed and quality as delivered to televisions. Any-to-any connections are the true nature of this infrastructure; point-to-point connectivity no longer reflects the way media is consumed.
Sports applications have driven the adoption of IP networks, which deliver the speed and efficiency needed by live event coverage.When properly managed, proven IT practices and IP technologies can be much more efficient and optimize many aspects of an operation — from physical resources to bandwidth — relieve financial burdens, and enable management of capital expenditures. At the same time, IP networks can provide significant value-added services, including social media capabilities.
Despite the inherent flexibility of IP transport, its cost efficiencies and the ubiquitous availability of IP networks, broadcasters still show reluctance to deploy IP for mission-critical broadcast operations. Broadcaster fears over losing apparent workflow control, and concerns over quality and security, persist. IP for the transport and management of live video sits diametrically opposed to tried-and-tested linear broadcast systems. Packet technology entails chopping signals into fragments and transporting them over an IP network for a loss of all perceived control.
Advantages of IP networks
The latest achievements in QoS, resilience, fast repair, switching speeds and scalability have made IP networks reliable enough to become not just viable, but a preferred option for video contribution networks.
The use of IP for contribution-quality video transport has also grown out of the need for efficient scaling of bandwidth. In many cases, IP’s scalability has been enhanced through the use of video compression technology such as MPEG-2, H.264 and now JPEG 2000. Compression allows for every bit of available bandwidth to be optimized.
For live sports productions, IP transport reduces the need for remote broadcast and satellite uplink trucks and reduces resources required for on-site personnel, saving production and operational costs. Yet IP’s advantages extend beyond operational and capital-expense cost reductions. The ability to share content quickly and efficiently on a shared IP network infrastructure creates collaboration, efficiency and agility throughout the entire broadcast value chain. Perhaps nowhere has this been seen more than in sports production, where workflows are being transformed by IP networks and all-digital systems. The resulting highly integrated workflows and efficiencies have opened the door for new second-screen solutions, providing an opportunity to leverage the often-large amounts of unused content as original premium content sent to viewers’ second screens. This serves the dual purposes of engaging viewers as they consult other devices and engage in social media activities as they view their favorite sports, while creating potential new revenue streams.
An IP environment supports an end-to-end digital workflow that dynamically moves media through the production process, breaks down operational silos and supports collaboration internally. As a result, digital workflows can reduce OPEX, allow editing functions to be easily shared among different teams and significantly reduce time to air — especially important in sports and news environments.
The first stage in the lifecycle is the acquisition of video content into the IP domain. Adapting digital video onto an IP network can be achieved either directly from cameras with built-in Ethernet/IP network interface cards, or via standalone IP video adaptors or gateways.
With IP transport, the network itself determines the optimal path for transmitting traffic to its destination at any given moment and routes traffic dynamically. Rather than predetermined transmission paths set up in advance, TS packets serve as containers, which are stamped with a destination address and sent into the network. The network then uses the IP addresses to transport the packet to its destination through connectionless packet forwarding, or IP routing.
The connectionless approach of IP networks offers several advantages. First, because no paths must be established in advance, provisioning is easier and more cost-efficient. IP networks are also inherently resilient. Because no paths are pre-established, an IP network will always reroute around any link or router failure (assuming the network has been designed with resilient nodes and links). This allows IP networks to survive multiple link and node failures — something not always possible with path-protected networking technologies.
SIDEBAR: Three decoders support 16 remote locations
When the production arm of a major sports league decided to move beyond file-based transfers and give its on-site studios the tools and flexibility to create compelling live sporting packages, an entirely new workflow was developed to gather, transport and manage video feeds. An IP network encompassing video compression and integrated management software enabled remote local production sites to transfer live SD content over a 100Mb/s IP circuit. Identical set-ups at each of the 16 stadiums were required to support the new solution: two Sony BRC-Z700 robotic cameras, one handheld Sony XDCAM EX3 camera and an Apple computer equipped with Final Cut for local editing. Robotic cameras could be remotely operated from the primary facility or from the local studios, with content streamed in real time.
A move to an IP-managed workflow gave a major sports league the workflow to support 16 remote locations with three decoders.
A system management platform makes the connection to the central site, allowing on-site producers to set up video-over-IP connections and record directly to the main production facility, or record locally and transfer the files at a later time using editing software, for an entire process managed over IP. Through connection management software, the main production facility is able to use only three decoders in support of 16 different locations — dynamically shifting the connections where they’re needed, either scheduled in advance or on an ad-hoc basis. On-site studios can connect directly to the production studio or use Web-based tools to manage content, with the management software providing scheduling, provisioning and monitoring of video-over-IP services.
The ability to link to 16 different locations on an as-needed basis, receiving content where and when it’s needed and according to the match schedule, enables faster and more flexible content delivery, saving the costs of many more permanent connections.
Video compression helps overcome the bandwidth constraints of the network transport infrastructure. Typically, compression involves a tradeoff between bandwidth availability, transmission cost and the level of quality required for video services at the different stages between capturing the content and delivering it to the end user. The appropriate video compression and the requirements of the underlying network depend on the specific application. For sporting events, or when transporting video feeds among teams in a production facility, video quality is prioritized above all else, requiring very high bit rates.
For our IP example discussed earlier, SD video was compressed and mapped to IP with near-mathematically-lossless compression with identical modules deployed at the transmitting and receiving ends of the system. The goal is to guarantee the highest possible visual quality with absolute minimal degradation through multiple encode/decode cycles.
Network management and quality of service
Real-time audio and video services are extremely sensitive to packet loss and delay. A quality-of-service (QoS) model must be applied to ensure that over-subscription of data will not cause video packet loss. As a result, any IP infrastructure operating in a broadcast environment must meet stringent performance and availability requirements. It must provide extremely low jitter and low delay—typically less than 80ms. To protect against delay and packet loss, broadcasters must eliminate network congestion and tightly control the amount of traffic traversing all links in the network. Other critical functions of an IP network — including service provisioning and analytics, network inventory, protection and performance management — should be controlled and managed. With today’s tools, the task of 100-percent guaranteed QoS should not be daunting, as many incorporate Forward Error Correction (FEC) and a wide range of even more efficient protection schemes that correct issues caused by media adaptors in the network.
As an industry, we’re building toward a time when infrastructure will cease to be a discussion point. Next-generation networks will reflect true marketplace convergence, enabling unfettered user access to high-quality content of their choice, any time, anywhere and on any device.
—Thomas Heinzer is strategic project manager and founder of Nevion.
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