Keywords: IPTV, How IPTV technology works, IPTV Network Protocol, IPTV Architecture
Recently the analog television gradually yields the way to digital television. The digital television allows to increase the quality of broadcast video and audio and enlarge the number of TV programs transferred in one frequency range.
DVB(Digital Video Broadcasting) is the most popular suite of internationally accepted open standards for digital television. DVB standards are listed by the signal transfer method: satellite (DVB-S, DVB-S2), cable (DVB-C), terrestrial television (DVB-T). Yet still DVB is a one-way television, so it lacks interactive features that would allow users to affect the playback.
The next generation of television is two-way digital television with some interactive features. Now users can watch TV programs and control the playback. For example, you can pause the live TV show to resume it later, and then fast forward through the commercial block. This is the power being provided by IPTV.
So question is what is this IPTV technology?
What is IPTV ?
As from Wikipedia
Internet Protocol television (IPTV) is a system through which services are delivered using the Internet protocol suite over a packet-switched network such as the Internet, instead of being delivered through traditional terrestrial, satellite signal, and cable television formats.
Definition (reference form Wikipedia)
Historically, many different definitions of IPTV have appeared, including elementary streams over IP networks, transport streams over IP networks and a number of proprietary systems.
One official definition approved by the International Telecommunication Union focus group on IPTV (ITU-T FG IPTV) is:
IPTV is defined as multimedia services such as television/video/audio/text/graphics/data delivered over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability.
Another more detailed definition of IPTV is the one given by Alliance for Telecommunications Industry Solutions (ATIS) IPTV Exploratory Group on 2005:
“IPTV is defined as the secure and reliable delivery to subscribers of entertainment video and related services. These services may include, for example, Live TV, Video On Demand (VOD) and Interactive TV (iTV). These services are delivered across an access agnostic, packet switched network that employs the IP protocol to transport the audio, video and control signals. In contrast to video over the public Internet, with IPTV deployments, network security and performance are tightly managed to ensure a superior entertainment experience, resulting in a compelling business environment for content providers, advertisers and customers alike.”
The IPTV technology allows to broadcast television into IP networks with HD video and multi-channel audio. To achieve that, it requires: an IP network with multicast broadcasting support, a head-end that receives external digital TV signals and manages all the IPTV system, and set-top boxes for subscribers’ TVs. The IP protocol allows to organize two-way connections between head-end and set-top boxes. Thank to all that, users can enjoy the interactive TV and other media features not available to classical television subscribers.
While reading this don’t be confuse with Internet TV or TV over Internet, that is different and not related to IPTV. In breif Internet TV is a Video streaming technology over internet.
Note: All differences will be updated later when time permits.
Services offered by IPTV :
Besides classic tv channels , IPTV also provides following interactive services:
|
S.N. |
Service |
Description |
|
1 |
Video on Demand (VoD) |
It is an individual delivery of video content to a subscriber. This service allows its users to order for watching any movie from the VoD server’s media library. The subscriber can use the pause and rewind features. |
|
2 |
Near Video on Demand (nVoD) |
It is a pay-per-view video service like VoD but intended for multiple users subscribed to nVoD service. The schedule of content broadcasting is compiled beforehand. Subscribers can look through schedule and plan watching the content of interest. |
|
3 |
Time Shifted TV |
It adds interactive features to TV channels watching. The subscriber can pause the playback at any time and resume it later. There is also a rewind option for TV programs. |
|
4 |
TV on Demand (TVoD) |
The selected TV channels are recorded to be viewed whenever the customer finds more convenient. |
|
5 |
Live Television |
with or without interactivity related to the current TV show. |
The IPTV Architecture :
The first required component is head-end, the hardware and software complex that receives, records, and stores the content, as well as manages services and subscribers. Set-top boxes for users’ TVs are also needed. Set-top boxes are the clients of the head-end.
A head-end contains a number of components:
-
DVB to IP Gateway
IP Gateway is the device that receives satellite, cable, or terrestrial TV signal and broadcasts it into an IP network in multicast mode.
-
Middle ware
Middle ware is the central part of IPTV system as it ties subscribers’ IP set-top boxes to the IPTV head-end and defines the user interface and the set of available services. In fact, Middle ware coordinates pretty much everything in an IPTV system. -
Billing system
Billing systems accounts and tariffs all consumable services. It is sometimes called SMS (Subscriber Management System), since it allows to manage subscriber base, payment cards, administer tariff plans and financial statements. -
VoD/nVoD server
This server unit is necessary for providing Video on Demand services. The device contains hardware storage with multimedia library. The content from the library is provided on subscriber’s demand. -
TVoD/Time Shifted TV server
To provide services like TV on Demand and Time-Shifted TV, you also need a separate server unit that would record selected TV channels and broadcast them on subscriber’s demand. -
Conditional Access System (CAS)
This is an optional component of IPTV system. It protects the content by requiring passkeys. The operator can manage the access for individual subscribers. The encrypted streams are transmitted over open channels.
IP-network
The IP network with multicast support is required for IPTV system. Multicast is a mode of delivery directed simultaneously to a group of IP adresses. The IGMP querier and multicast IGMP switch are necessary.
Clients equipment
-
IPTV PC Client
There is a software that allows users to access the IPTV services by personal computer. Using the IPTV PC Client subscribers can watch TV-channels and access all additional IPTV services. -
Set-top boxes
Set-top boxes (STB) are required to access the IPTV services on TV screen. They are the connecting link between Middleware, content sources and subscriber’s TV. A set-top box receives the signal via an IP network and converts it into supported formats.
Content for IPTV
The IPTV content may be streamed or recorded, for example Video on Demand. The recorded content is stored on the VoD servers. There are two kinds of streamed content received from external satellite, cable or terrestrial source:
FTA (free-to-air). The number of unencrypted channels received from one source depends on transponder’s or multiplex’s bandwidth.
PayTV, i.e. encrypted channels. PayTV channels need decryption by a Conditional access module (CAM). For different encryption systems you need different CAMs. The number of channels broadcast from one source depends on CAM performance because each CAM can decrypt simultaneously only a limited number of channels.
IPTV Protocol Layer
Communication between STB and IPTV Server
Conclusion:
IPTV technology is the future of television and other IP based services. As of now many telecom operators are providing triple/quard play services. In single conneection user can get mutiple services.
Today’s tecnologies are rapidly growing. There is a lot of scope to add more interactive services in IPTV system. Just wait n watch where this technology go now.
Later on , here on Techawarey more information will be added related to IPTV technology. Till then keep reading .. 🙂 And Dont forget to Like and Share 😉
Note: Description on IPTV network protocol will be updated soon.
Referneces :
1.http://www.netup.tv/en-EN/introduction_into_iptv_en.php
2.http://en.wikipedia.org/wiki/IPTV
3.http://www.slideshare.net/Cynapsys/architecture-iptv-7100292