Optimizing Use of PTP for SMPTE ST 2110
What are the potential challenges?
Q: What is SMPTE ST 2110, and how can broadcasters leverage the standard to efficiently transition to IP?
A: SMPTE ST 2110 enables separate, location-agnostic production flows for video, audio and data components/essences of traditional TV services, using an all-IP approach. The standard abolishes the requirement for two separate sets of switches—SDI switches for professional media and IP/Ethernet switches for general data—allowing facilities to rely on one common data center infrastructure.
The transition to ST 2110 also entails the availability of Precision Time Protocol (PTP) time sources and, to support signals up to Ultra High Definition (UHD), requires 25 GbE or higher grade network interfaces.
For cost-effective transitions from SDI to IP, broadcasters can leverage SMPTE ST 2110 encapsulators, also known as “IP Media Gateways,” which provide IP encapsulation and decapsulation for video, audio and metadata, and provide dense solutions that typically come with custom FPGA-based designs.
Media processing solutions further complement SMPTE ST 2110 environments by providing, along with a wide range of media processing functions, the SMPTE ST 2110 ingress and egress functions. There are also extensive diagnostic and monitoring tools to make the transition to media over IP as smooth as possible.
Plus: What SMPTE-2110 Means for Broadcasters
What is PTP, and what is its role in broadcasters’ shift to IP-based infrastructure?
PTP coordinates the timing for all audio, video and metadata packets, allowing for wide network system synchronization regardless of the physical location of the equipment itself. This concept enables Local Area Networks (LANs) to extend throughout a building, across a campus or between geographically separated environments for unprecedented flexibility and efficiency in distribution workflows.
PTP time-based infrastructure and 25 GbE network interfaces, ideally with hardware timestamping, are required to facilitate the transition from SDI to IP. Broadcasters can leverage SMPTE ST 2110 receivers, which are synchronized to global PTP time sources, to help ensure packet timestamps corresponding to essence access units are matched up to accomplish highly accurate time alignment for all essences.
What are potential challenges that can arise from the routing process, and how can they be overcome?
With PTP, packet loss and routing errors can be prevented with hitless merge redundancy provided by SMPTE 2022-7. Furthermore, existing ST 2110 solutions empower users to tune hitless merge reception via playout and synchronization delay parameters. Playout delay defines the buffer that is used to compensate for jitter and the window that is used for packet reordering. For hitless merge, this delay determines the buffer that can compensate for the delay between both paths.
Broadcasters are increasingly seeing the benefits of migrating to IP infrastructures, and many will look to work with a vendor that can provide the right tools and expertise for leveraging SMPTE ST 2110 and PTP. The Canadian Broadcasting Corporation (CBC)/Radio Canada, for example, tapped Synamedia’s Video Network portfolio to assist with its transition from SDI to a SMPTE ST 2110 IP-based infrastructure. With the new standard, broadcasters will experience unprecedented agility, flexibility and efficiency in their content delivery workflows to provide optimized, infinite video experiences.
Jovo Miskin is senior engineering manager for Synamedia.
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