Level 3 Communications State of Transmission Report, Part 2: Delivering pixel-perfect video is different to email
What does the latest generation of broadcast fibre transmission service look like from a sports venue, and what services should production and technical teams be asking for? To answer this fully, write Jeffrey Hallman, Elio Parente, and Derek Anderson, Level 3 Communications, it’s important to first understand the scope of all applications being used as part of the live sports broadcast production workflow.
Live linear contribution and distribution streams
This is the main transmission feed (might include multiple ISOs for ‘at home’ production or baseband video highlight clips ultimately destined for CDN delivery to a website) and requires the most protection and resiliency. Depending on the types of compression available, the bit rates can vary. In most cases, a physically diverse path is required.
When speaking to a telecommunications provider, it should be decided up front how the signal diversity should be set up. With the use of multiple VLANS, it can become confusing and cause troubleshooting issues later if the terminology used from the beginning is not agreed upon.
Will you have a Main and Backup with the same content on each to take different routes across the network? What level of network protection is then required on the access circuits? Or will you have a Primary and a Secondary with different content on each and look solely at the network to provide the necessary levels of diversity and protection?
Return video back to event remote facility
The duplex nature of Ethernet and IP-based services has made the traditional confidence return path a viable solution – without requiring a secondary satellite truck for downlink – for sending high-quality video from base back to the venue. In other words, the return path can now be utilised as a contribution feed.
Care should be taken to match the outbound compression rates if the content received is to become part of the main outbound programming. If a full-time confidence return is also required, then a lower bit rate feed can be used to save on overall bandwidth budget, as it usually just ends up in a multi-viewer for viewing purposes only.
Data-specific applications ancillary to the “Live Video Feed”
- Hi-res file transfer
- graphics package transfer
- post production, editorial decision-making
This area is where the most growth has been in the deployment of Ethernet and IP services, for these are more critical and time sensitive tasks. The ability to create/publish and deliver file-based material in both directions between the At-Home facility and the venue has given the production team the means of working faster and smarter.
No need to wait until the live transmission is over and “the lines clear” to send the daily highlights or any other content in both directions. With the use of VLAN configurations on the Ethernet service, “the pipe” can be divided up into as many “data services” as needed for the event.
One of the key advantages is that all metadata can then be sent with the original file. The fact that broadcasters can now send large files in tandem with the live TX output of the show, brings with it its own special concerns. Oversubscribing of Ethernet- and IP-based circuits does happen.
Large spikes of file-based data also impact video transport streams if the correct CoS/QoS is not applied to manage when the file is sent. Rate-limiting rules should be applied. The decision on how much traffic a production team will have versus the live content for it all to fit neatly in the same circuit needs to be addressed. It is not simply a matter of deciding on a couple of video feeds and “whatever is left will go to content file sharing apps.”
IP-based voice communications (IFB Intercom, Telephony)
Communication applications such as these are crucial to live sports broadcast production. Basically, you can’t televise live sports without the intercom.
The nature of Layer II/III configurations is important here because of the issue of who is managing the equipment IP addresses. With Intercom and IP telephone systems being deployed to provide real-time conversations on a remote, the most savings and efficiencies are found when it is “tethered” to the central system at a broadcaster’s home facility.
This means having the discussion in advance about how these networked systems are going to be managed onsite. Once the VLANS are created, it will be up to the broadcaster to establish any connectivity between the devices. Some understanding of Layer II/III configurations is required because the provider’s network will be transparent.
Video asset and communication security/virus and malware protection
From standing up full end-to-end corporate VPN and firewalls as mandated by the company IT and network security teams, to protecting the value of the live content asset from being accessed by unlicensed entities, the protection afforded by IP networks is nearly bulletproof when the right precautions are taken.
There is an inherent risk in using the public internet in this case, but this generally is mitigated by the aforementioned network security teams. Fully private networks managed by a telecom provider come with the added layer of network security specialists as standard, and can provide that extra layer of protection the content’s value demands.
Secure corporate communications for production coordination (email) and access to home office systems. Generic web access for access internet resources, hosted cloud-services
Access to email and other private and public web services have the smallest appetite for bandwidth. However, it has become one of the most critical dependencies seen at remote locations during a broadcast. It also usually is required from Day 1 of the production team being on site. It is the most common requirement of using off the shelf components with the smallest bandwidth. If these types of data services are used, they need to be setup far in advance of the main video transmission.