By John Horrobin, Yoav Schreiber, Cisco Systems
Cable operators are leading the industry with innovative cloud-based video solutions such as TV Everywhere and Cloud DVR. These solutions are expected to play a prominent role as operators aim to deliver more content to more devices and ultimately transition to all-IP with full-scale, managed IP Video services. With current-generation IPTV solutions, operators have the choice of using unicast or multicast to deliver Linear TV services, and multicast has proven to be very efficient in existing IPTV deployments. However, cloud-based video solutions currently rely exclusively on unicast delivery, which can have a dramatic impact on the cable access network as the number of subscribers served from the cloud grows. Thus operators need to carefully consider the network impact of migrating to cloud-based video solutions, and look for ways to optimize the network efficiency. Using example use cases based on field data and our own assumptions, we illustrate the potential for as much as 80% savings in CMTS capacity and HFC spectrum using multicast delivery for real-time viewing and in-home DVR recording. While moving the DVR functionality to the cloud can increase the network capacity required for time-shifted viewing by 40% in our example, it can also significantly decrease the control plane traffic load on the CMTS during prime time. Even with cDVR solutions in place, we expect multicast will continue to be a valuable tool for cable operators in serving non-cDVR subscribers. Hybrid DVR solutions can offer the best of in-home DVR and cDVR solutions if the business case challenges can be overcome. Many cable operators have deployed TV Everywhere solutions as an overlay to their existing digital cable systems. As operators migrate to all-IP, there are clear benefits to using a common platform for delivering both managed and unmanaged IP Video services to all devices. The TV Everywhere solutions deployed to date can serve as a foundation for the common platform to support all IP Video services in the future. Since these solutions typically employ ABR streaming, the development and deployment of multicast ABR video transport solutions will enable operators to leverage the benefits of multicast as they migrate to a common infrastructure and client for supporting all IP Video services. While the optimal solution for delivering full-scale, managed IP Video services will be unique to each operator, it will undoubtedly involve both multicast and unicast delivery approaches.