By Shlomo Ovadia, Ph.D. & Jenson Thottian, Charter Communications
Cable operators are responding to their subscribers’ insatiable appetite for TV programming with new innovative video solutions such as Cloud-DVR (cDVR) and TV Everywhere [1, 2]. cDVR solutions move in-home recording and playout functions to the cloud, and thus enabling remote access of the recorded Linear TV content on a variety of platforms such as laptops, tablets, cellphone, and TVs. cDVR has many advantages such as cost, performance, operation, and business intelligence compared with in-home DVR.
For example, no truck-rolls are needed to deploy and fix cDVR issues. The cDVR service offers a virtually unlimited number of tuners, enabling customer to record more than two shows at a time, and providing completely scalable and redundant storage capability. This feature allows customers to easily increase the amount of paid storage without any changes to their home network. Furthermore, cDVR based solutions allow cable operators to deploy faster, and to use more cost-effective CPE devices such as Charter’s Worldbox 2.0 with traditional and cloud-based interfaces [3].
However, unlike the in-home DVR use case in which all the time-shifted recorded content is served locally, and thus has no impact on the cable network, cDVR has several infrastructure performance costs to consider. The cDVR use case requires network capacity on the cable access network, and storage capacity for the recorded content. The cDVR solution utilizes unicast video delivery for each subscriber, the total required network capacity is proportional to the number of concurrent cDVR subscribers viewing the timeshifted content. One of the potential cDVR obstacles is the copyright challenge by content providers. In the Private Copy deployment model, the cDVR permits each subscriber to record, store and playback a private and unique copy of the selected content (e.g., Private Copy). This means the cDVR storage capacity is linearly proportional to the number of subscribers. Another deployment option for cDVR is the hybrid storage model where the Private-Copies are maintained for 3 days after the record-time [4]. If the Private Copies are not viewed by then, they can be deleted (“de-duplicated”) by the cDVR system and saved only as a Shared-Copies (same recorded content is shared among multiple subscribers). Thus, in this model, the amount of required storage for each subscriber can be significantly reduced compare with the Private Copy model.