Introduction into IPTV

Evolution of the television

Recently the analog television gradually yields the way to its digital counterpart. 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.

What is IPTV

Local IP networks allow to take advantages of all features of two-way television. Network technologies are widely spread at the moment. They are used for Internet connection, IP telephony and also IP television. 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.

Besides classical TV channels, IPTV provides additional interactive features:

• 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.
• near Video on Demand (nVoD) 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.
• Time Shifted TV 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.
• TV on Demand (TVoD). The selected TV channels are recorded to be viewed whenever the customer finds more convenient.

IPTV advantages compared to classical television:

• Interactive features: user can control the playback and store the TV show or program for later watching.
• Additional multimedia services: VoD, nVoD.

Required components for IPTV solution

Let's try to realize what is necessary for starting the IPTV project. 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.

1. 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.

2. Middleware
   Middleware 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, Middleware coordinates pretty much everything in an IPTV system.

3. 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.

4. 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.

5. 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.

6. 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

1. 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.

2. 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.

We have considered all IPTV components in detail and made it clear that an IPTV system contains a lot of high-performance and complex devices:

• IP network with multicast support.
• DVB to IP Gateway for receiving external TV signals (a separate device).
• Middleware and billing system (a separate device).
• VoD / nVoD server (a separate device).
• TVoD / Time Shifted TV server (a separate device).
• Conditional Access System (a separate device).
• IP set-top boxes.

Generally, each IPTV component comes from its own manufacturer, so the components must be patched together, thus increasing the timing and complexity of project's deployment.

If you use the NetUP's IPTV system, all components are naturally compatible with each other, so you don't need to waste your time and money for the integration. Thanks to this, the cost of project's deployment decreases significantly. But for small IPTV projects, such as hotels, hospitals or yachts, a large-scale IPTV system may still be overly complex and not cost-effective.

NetUP has developed the IPTV Combine 4x especially for small projects with less than 500 subscribers. This server unit contains all necessary components in one piece: DVB to IP Gateway, Middleware, Billing system and VoD/nVoD server. NetUP IPTV Combine 4x is relatively easier to install, customize and supply, and greatly cheaper compared to a full-fledged IPTV system.

IPTV Combine 4x has built-in 1 TB HDD storage. The device's performance allows to broadcast more than 50 simultaneously VoD streams and to receive external TV signals from 4 different transponders or multiplexes. Optionally, an additional DVB to IP Gateway can be installed to increase the number of received channels. TVoD server and CAS can be also installed.

Components required for starting a small IPTV project:

• IP network with multicast broadband support.
• NetUP IPTV Combine 4x.
• IP set-top boxes.
• Optionally, extra TVoD server, DVB to IP Gateway, and Conditional Access System may be installed.