Internet Protocol Television (iptv)

IPTV (Internet Protocol Television) A Technical Note VMG ([email protected])

IPTV (Internet Protocol Television)

Technical Note

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IPTV (Internet Protocol Television) Contents 1

What is IPTV .......................................................................................................................................... 4

2

Unicast Vs MultiCast ............................................................................................................................. 5

3

Network Diagram of IPTV System ......................................................................................................... 5

4

IPTV Architecture .................................................................................................................................. 5 4.1

Content/Headend ......................................................................................................................... 7

4.2

Core Network: ............................................................................................................................... 8

4.3

Telco Access Network ................................................................................................................... 9

5

Video Streaming Protocols.................................................................................................................. 10

6

References .......................................................................................................................................... 11

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IPTV (Internet Protocol Television)

1

What is IPTV IPTV is Internet Protocol TV which means television services over the Internet or Internet Protocol. Many people are confused with Internet TV with IPTV. Internet TV is where movie is played all ready stored in the server. You would have seen bit torrent, online movies these are internet TV where as IPTV is the real television streamed through internet rather than through cable. This delivery of digital television is made possible by using IP over broadband connection. IPTV contain the Data, Audio and Video which is also called Triple Play. To understand how IPTV changes the business of television we need to first discuss the current business of television. The television service industry can be divided roughly into content owners and creators, content distributors, and advertisers. The owners and creators are the major networks (ABC, CBS, and so on), the cable networks (CNN, HBO, and so on), and the movie studios (otherwise known collectively as Hollywood). In general, the content owners do not sell their content directly to consumers. Instead, the content is aggregated, packaged and sold to consumers via content distributors or multichannel video program distribution (MVPD) services. Today these are primarily the local TV broadcast stations (who may be owned by the major networks), cable operators (who may own cable networks), and direct broadcast satellite (DBS) operators, namely DirecTV and EchoStar in North America.

Technical Note

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IPTV (Internet Protocol Television) 2

Unicast Vs MultiCast A unicast session is the conventional networking method two computers use to communicate with one another within private one on one environment or session. In IPTV, VOD server is best example for the Unicast. Take an example, typical IPTV network consists of VOD Server, IPTV Network and STB (Set Up box) which is connected to Television. User usually controls IPTV through the remote control which is given along with STB box. Take an example user wants see a movie, first she sends a command to through the STB to VOD server the web pages. This is the unicast only between use and VOD server. Then user finds the title of movie start purchasing that movie. It is also unicast between the user and VOD Server. The communication enables the client to control VOD Server is through RTSP (Real Time Streaming Protocol) Multicast is the process of process of single source sending to multiple destinations at single time. Using IGMP, clients are able to receive the broadcast packets and enable the routing of the broadcast stream to network. IGMP allows an individual host machine to “Join” and “leave” multicast groups by responding to queries by a mulicast capable router. MultiCast enables a video server to broadcast to a video network. It saves a tremendous amount of network bandwidth over unicast, but there is no reliability mechanism so lost packets stay lost.

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Network Diagram of IPTV System

4 IPTV Architecture 



Content/Headend. The source for much of the video content within the system. The central point within the network is the headend or super headend. This is where the broadcast programming and ondemand content is captured or ingested into the system. Core Network. Transports all of the system's content (that is, video, music, channel lineup, and data). The core network is the "backbone" for the IPTV broadcast system within the region of service. Also, local content and local advertisement insertion for each region could be inserted at the core network.

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IPTV (Internet Protocol Television)  

Access Network. The "last mile" for the network operator. It provides the network connectivity of the IPTV services to consumer homes. Home Network. Where the IPTV service enters the home (via a router/gateway). It is also where the distribution of all of the data (voice, data, and video) takes place among all IP devices in the home.

Many smaller operators obtain content from the “Content Aggregator” that acquires the various programming in bulk and makes it available to many operators. The super headend is where the bulk of content is captured and formatted for distribution within a network, including the broadcast and on demand services. After content is captured via within the headend, it is formatted to distribution within the system. This includes the coding schemes ie., MPEG-2, MPEG-4 etc., The statistical multiplexer, or rate shaper, may also be used to create the required bitrates for distribution network. The multiplex program streams are then encapsulated in IP Packets. The signal leaves the super headend over an extremely high bandwidth wide area network to Video hub offices (VHO) The WAN and VHOs constitute the core network. WAN is the backbone of the core network and uses high bandwidth IP transport formats such as gigabit Ethernet or ATM to connect the VHO Site. The multicast streams enter the video hub via the WAN. The video hub may also have local receivers, which offer additional local content. Local content is processed much like national content, possibly getting digitally encoded, transcoded or turned around. Each region will have its own unique channel lineup, which would include the numerous multicast broadcast channels and VOD channels. IPTV data then travels the VHO (core network ) to (access network) video central offices (VCO) over a high bandwidth network. Each VCO will route data to video network access interfaces. Technical Note

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IPTV (Internet Protocol Television) In the Telco case, the DSLAMs route the desired video data from the network over a twisted pair DSL line to the consumer’s home

4.1 Content/Headend

The equipments used in the Headend is similar to digital cable television headends. But equipments are based on PC server platforms used for most web application rather than cable technology The following functions of Content/Headend o Content Reception: Consists of components that receive both analog and digital video feeds either directly from the content provider or from a content aggregation facility such as provided by the National Digital Television Center o Signal Conditioning: Consists of signal processing equipment designed to enhance the video signals coming in from the content reception equipment. This might include integrated receiver decoders (IRDs), noise reduction, and digital video processing products o Content Preparation: The content encoders prepare the video streams in a format that is suitable for IP transport and reception by an IP STB. This will consist of either digitizing (and encoding) analog content or transcoding digital video content into the format used by the codec employed by the IPTV system o Digital rights management: As part of the encoding process, the encryption component of the digital rights management (DRM) system encrypts the content and wraps it in a DRM container to prevent unauthorized usage of content. o DRM License Server: Manages, authorizes and reports content transactions as well as manages the encryption of content of data. The server verifies content license requests and issues content licenses to trusted, authenticated DRM end user clients. o VOD Servers: VOD or Media Servers are optimized to serve multiple streams simultaneously to clients. Content may be stored on the server for multicast (a single stream sent simultaneously to multiple viewers) to an ensemble of viewers at a fixed Technical Note

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IPTV (Internet Protocol Television)

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time, or for unicast to individual users in a VOD system. Depending on the system architecture, VOD servers can reside either in the super headend or in the core network (VHO). Application Server: The application servers can vary greatly between IPTV deployments, depending on features, functionalities, scalability, middleware, system control, and so on. Application servers could include electronic program guide (EPG), Conditional Access System (CAS)/DRM servers–entitlement, navigation/ middleware server, IPTV portal or walled garden, e-mail, and remote diagnostics. Much like VOD servers, application servers can reside either in the super headend or in the core network (VHO). Billing system. The subscriber database contains subscriber specific information with respect to the level of service the user is authorized to use and other information to be used for billing Gateway/load balancer. Provides load balancing and session control and sends the data stream to the network interface.

4.2 Core Network: Core network consists of fiber backbone (WAN) and various VHOs. The core network gets data from the super headend (content/headend) and delivers data to the access network. The primary purpose of the core network is to provide adequate bandwidth for all of the data and video network traffic between service areas and the national content (super headend) source The core network also provides the capability for insertion of local content (including emergency alert system, or EAS) into each service area.

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IPTV (Internet Protocol Television)

4.3 Telco Access Network

Access network provides the network link core network to consumer homes. It provides a network translation from the switched network to whichever access technology the network the operator uses to get data into customer homes as well as the last critical step in connecting homes to the overall network. The access network always called “Last mile”. Technical Note

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IPTV (Internet Protocol Television) 5 Video Streaming Protocols Multimedia and Networking is the core to IPTV. Multimedia application utilizes the various media types such as text, graphics, animations, audio, and video. The task of streaming and decoding digital audio and video over IP network provides a new set of challenges. The video streaming protocol mainly addresses the Quality of Service Time Management Session Management VOD trick mode support Various Streaming Media Protocols:

FTP (File Transfer Protocol) HTTP (Hyper text transport Protocol) RTP (Real Time Protocol) RTCP (Real Time Control Protocol) RTSP (Real Time Streaming Protocol)

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IPTV (Internet Protocol Television) 6 References IPTV Crash Course by Joseph weber and Tom Newberry.

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