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Oh freddled gruntbuggly, Thy micturations are to me.so began the poetry read by Prostetnic Vogon Jeltz to Arthur Dent and Ford Prefect, captured stowaways on a Vogon ship (from Douglas Adams' Hitchhikers Guide to the Galaxy). While this poetry is a thing of beauty to Vogons, it becomes a form of torture to Dent and Prefect. When two worlds collide communication and language can become a serious issue.
Closer to home the broadcast and telecoms worlds are converging and as they do, they face their own significant technical and linguistic challenges. The convergence is being driven by the telecommunications companies who find themselves in an increasingly difficult market. Their mobile markets are reaching saturation limiting growth, with revenues from fixed voice and data services dropping as they face aggressive non-traditional competition from the cable industry and VMNO's such as Virgin Mobile. In their bid to fight back, telco's see the delivery of broadcast video over their modern IP networks as a critical strategic opportunity. They are investing heavily in an attempt to capture more subscribers, decrease churn and increase their revenues.
Coupled with the commercial drivers, the technologies required to enable this transition are now a reality. Video compression technologies like H.264 (MPEG-4/AVC) and VC-1 allow the delivery of high quality video over limited bandwidth links. There are a variety of access technologies (xDSL, FTTx, WiMAX) available to provide the last mile connectivity to the home. DRM technologies have now matured to a point where they provide sufficient protection to encourage content providers to give access to their media for distribution over IP networks.
The above list of technologies provides a glimpse of some of the basic communications issues in the converged world. Broadcasters are familiar with the compression technologies but their colleagues in the IP world are not. The complexity rapidly increases in circumstances where the video is delivered to the compression facilities as baseband digital video. The converse is true with access technologies. Few (or none) of the technologies listed will be familiar to those used to delivering content over closed broadcast networks (cable, satellite or terrestrial - all of which use a number of different RF modulation schemes). IP engineers who find themselves in a broadcast world and vice-a-versa are faced with an alarming array of new terms, acronyms, protocols, technologies and methodologies.
One of the major advantages of using IP networks as a mechanism for delivering TV is the bi-directional nature of the network. This provides the end user previously unheard of control over their viewing experience. They have the ability to choose what they watch, when they watch it, what they watch it on and where they watch it. Video on Demand (VoD) has arrived.
In traditional broadcast networks content is uni-directionally "pushed" to the home and all programs are available at the STB (Set Top Box) often called the CPE (Customer Premise Equipment) by the telco's. CA (Conditional Access) determines whether or not the end user can actually view the content, but it is all delivered to the STB. The control and selection of the channel to be watched occurs within the STB in response to requests from the user's remote. In IPTV systems, two mechanisms are employed to deliver TV to the home. The standard collection of broadcast channels are delivered over multiple Multicast IP sessions (using MPTS) and VoD is delivered over Unicast IP sessions (using SPTS)
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