IPTV is distinctly different from “Internet Video” that simply allows users to watch videos, like movie previews and web-cams, over the Internet in a “best effort” fashion with no end-to-end service management and quality of service considerations.

IPTV technology, integrated with the higher speed digital subscriber line (DSL) access technologies (ADSL2, ADSL2+ and VDSL), offers attractive revenue-generating opportunities for the telecom service providers, enabling them to compete effectively in the “triple play” market space with the delivery of voice, data and video services to residential and business customers.

This is an overview of the IPTV system architecture and identifies some near-term applications that may be supported by the telecom service providers. In addition, it addresses generic requirements for customer home networks to support the IPTV application which highlights the technology of PowerLine Communications.

The major functional components of the IPTV architecture are:

Content Sources - ‘Content Sources’ represents a functionality that receives video content from producers, and other sources, encodes the content and, for VoD, stores content in an acquisition database.

Service Nodes - The ‘Service Nodes’ represents a functionality that receives video streams in various formats, then reformats and encapsulates them for transmission with appropriate Quality of Service (QoS) indications to the wide-area network for delivery to customers. Service Nodes communicate with the Customer Premises Equipment (CPE) for service management and with the IPTV service for the subscriber, session and digital rights management.

Wide Area Distribution Networks – This provides the distribution capability, capacity, quality of service and other capabilities, such as multicast, necessary for the reliable and timely distribution of IPTV data streams from the Service Nodes to the Customer Premises. The Core and Access Networks include the optical distribution backbone network and the various Digital Subscriber Line Access Multiplexers (DSLAMs) located at the central office or remote distribution points.

Customer Access Links - Customer delivery of IPTV is provided over the existing loop plant and the phone lines to homes using the higher-speed DSL technologies such as ADSL2+ and VDSL. The distance limitations and bandwidths attainable for these DSL technologies are summarized below.
Service providers may use a combination of Fiber-to-the Curb (FTTC) and DSL technologies or implement direct Fiber-to-the-Home (FTTH) access depending on the richness of their IPTV service offerings.

Customer Premises Equipment (CPE) - In the IPTV context, the CPE device located at the customer premise provides the broadband network termination (B-NT) functionality at a minimum, and may include other integrated functions such as routing gateway, set-top box and home networking capabilities.

IPTV Client - The IPTV Client is the functional unit, which terminates the IPTV traffic at the customer premises. This is a device, such as a set-top box, that performs the functional processing, which includes setting up the connection and QoS with the Service Node, decoding the video streams, channel change functionality, user display control, and connections to user appliances such as a standard-definition TV or HDTV monitors.

IPTV Feature Continued