Saturday, October 24, 2009

IPTV - Internet Protocol TeleVision

Internet Protocol Television (IPTV) is a service for the delivery of broadcast TV, movies on demand and other interactive multimedia services over a secure, end-to-end operator managed broadband IP data network with desired QOS (Quality Of Service) to the public with a broadband Internet connection.

IPTV system may also include Internet services such as Web access and VOIP where it may be called Triple Play and is typically supplied by a broadband operator using the same infrastructure. IPTV services may be classified into three main groups: live television, time-shifted programming, and content (or video) on demand.

Major functional components of the IPTV architecture:
• Content Sources - It receives video content from producers, and other sources, encodes the content and, for VoD, stores content in an acquisition database. Acquistion database is used to access VoD faster.
• Service Nodes - It receives video streams in various formats, then reformats and encapsulates them for transmission with appropriate Quality of Service (QoS). Service Nodes also communicate with the Customer Premises Equipment (CPE) for service management like set-top boxes.
• Wide Area Distribution Networks - This is the core and access network that provides the distribution of IPTV data streams from the Service Nodes to the Customer Premises. The Networks include the backbone network and access equipments. For telecom operators, the Digital Subscriber Line Access Multiplexers (DSLAMs) is often used as the access equipment, while for cable operators hybrid fibre coaxial (HFC) is used.
• Customer Access Links - These are the existing loop plant and the phone lines to homes using the higher-speed DSL technologies such as ADSL2+ and VDSL. Service providers may also 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) - The CPE device 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 a device, such as a set-top box, that terminates the IPTV traffic at the customer premises. It performs the functional processing such as setting up the connection and QoS with the Service Node, decoding the video streams, channel change functionality, user display control, and connections to standard-definition TV or HDTV monitors.

IPTV Architecture Diagram