Monday, July 9, 2012

Edge based optimization part II: Edge packaging

As mentioned in my previous post, as video traffic increases across fixed and mobile networks, innovative companies try to find way to reduce the costs and inefficiencies of transporting large amounts of data across geographies.

One of these new techniques is called edge based packaging and relies on adaptive bit rate streaming. It is particularly well adapted for delivery of live and VOD content (not as much for user-generated content).
 As we have seen in the past, ABR has many pros and cons, which makes the technology useful in certain conditions. For fixed-line content delivery, ABR is useful to account for network variations and provides an optimum video viewing experience. One of the drawback is the cost of operation of ABR, when a video source must be encoded into 3 formats (Flash, Apple and Microsoft) and many target bit rates to accommodate network conditions.

Edge-based packaging allows a server situated in a CDN's PoP in the edge cache to perform manifest manipulation and bit rate encoding directly at the edge. The server accepts 1 file/stream as input and can generate a manifest, rewrap, transmux and protect before delivery. This method can generate great savings on several dimensions.

  1. Backhaul. The amount of payload necessary to transport video is drastically reduced, as only the highest quality stream / file travels between core and edge and the creation of the multiple formats and bit rates is performed at the PoP.
  2. Storage. Only 1 version of each file / stream needs to be stored centrally. New versions are generated on the fly, per device type when accessed at the edge.
  3. CPU. Encoding is now distributed and on-demand, reducing the need for large server farms to encode predictively many versions and formats.
Additionally, this method allows to monetize the video stream:
  1. Advertising insertion. Ad insertion can occur at the edge, on a per stream / subscriber / regional basis.
  2. Policy enforcement. The edge server can enforce and decide QoE/QoS class of services per subscriber group or per type of content / channel.

Edge based packaging provides all the benefits of broadcast with the flexibility of unicast. It actually transforms a broadcast experience in an individualized, customized, targeted unicast experience. It is the perfect tool  to optimize, control and monetize OTT traffic in fixed line networks.

1 comment:

G D SINGH said...

In the fixed networks, Live TV content is usually multicast.
On demand content is over Unicast.

For the mobile networks, yes the CDNs are using the Edge based packaging.
ABR is used, to provide fast user experience in terms of getting connected to the least bitrate stream to enable quick viewing of content requested -- Less/minimum buffering--
As soon as enough packets are recieved by the terminal, the stream is switched to higher bitrate (offcourse if enough bandwidth is available).
Higher bitrate stream enhances content quality.
ABR has definately reduced the bandwidth concerns over the backhaul.
One of the problems sometimes is that the Content provider do not allow the operator to Encrypt the content at Edge sites in the network.
Since the 'on demand' content is first stored at central site, it has to be encrypted before it is stored in any of the storage in the network.
Encrypting the (on demand) content like movies, on the fly just before streaming it.