Internet Protocol television

This article is about internet protocol television. For the public broadcasting in Iowa, see Iowa Public Television.

IPTV (Internet Protocol Television) is a system where a digital television service is delivered using the Internet Protocol over a network infrastructure, which may include delivery by a broadband connection. For residential users, IPTV is often provided in conjunction with Video on Demand and may be bundled with Internet services such as Web access and VoIP. The commercial bundling of IPTV, VoIP and Internet access is referred to as a Triple Play. Adding the mobile voice service leads to the Quadruple Play denomination. IPTV is typically supplied by a broadband operator using a closed network infrastructure. This closed network approach is in competition with the delivery of TV content over the public Internet. This type of delivery is widely called TV over Internet or Internet Television. In businesses, IPTV may be used to deliver television content over corporate LANs and business networks. Perhaps a simpler definition of IPTV would be television content that, instead of being delivered through traditional formats and cabling, is received by the viewer through the technologies used for computer networks.

History

In 1994, ABC's World News Now was the first television show to be broadcast over the Internet, using the CU-SeeMe videoconferencing software.

Internet radio company AudioNet started the first continuous live webcasts with content from WFAA-TV in January, 1998 and KCTU-LP on January 10, 1998.[1] [2][3]

In the past, this technology has been restricted by low broadband penetration. In the coming years, however, residential IPTV is expected to grow at a brisk pace as broadband was available to more than 200 million households worldwide in the year 2005, projected to grow to 400 million by the year 2010. Many of the world's major telecommunications providers are exploring IPTV as a new revenue opportunity from their existing markets and as a defensive measure against encroachment from more conventional Cable Television services. In the mean time, there are thousands of IPTV installations within schools, corporations, and other institutions that do not require the use of wide area connectivity.

As a result of the emergence of IPTV as an industry in its own right, dedicated trade shows and conferences have followed suit, such as IPTV World Forum Eastern Europe.

Architecture

Broadcast IPTV has two major architecture forms: free and fee based. As of June 2006, there are over 1,300 free IPTV channels available. This sector is growing rapidly and major television broadcasters worldwide are transmitting their broadcast signal over the Internet. These free IPTV channels require only an Internet connection and an Internet enabled device such as a personal computer, HDTV connected to a computer or even a 3G cell/mobile phone to watch the IPTV broadcasts. See also: Internet television Mobile TV

In December 2005, independently produced mariposaHD became the first original IPTV broadcast available in an HDTV format. Various Web portals offer access to these free IPTV channels. Some cite the ad-sponsored availability of TV series such as Lost and Desperate Housewives as indicators that IPTV will become more prevalent.

Because IPTV uses standard networking protocols, it promises lower costs for operators and lower prices for users. Using set-top boxes with broadband Internet connections, video can be streamed to households more efficiently than current coaxial cable. ISPs are upgrading their networks to bring higher speeds and to allow multiple High Definition TV channels.

In 2006, AT&T launched its U-Verse IPTV service. Comprised of a national head end and regional video serving offices, AT&T offered over 300 channels in 11 cities with more to be added in 2007 and beyond. While using IP protocols, AT&T has built a private IP network exclusively for video transport.

Local IPTV, as used by businesses for Audio Visual AV distribution on their company networks is typically based on a mixture of: a) Conventional TV reception equipment and IPTV encoders b) IPTV Gateways that take broadcast MPEG channels and IP wrap them to create multicast streams.

IPTV uses a two-way digital broadcast signal sent through a switched telephone or cable network by way of a broadband connection and a set-top box programmed with software (much like a cable or DSS box) that can handle viewer requests to access to many available media sources.

Protocols

IPTV covers both live TV (multicasting) as well as stored video (Video on Demand VOD). The playback of IPTV requires either a personal computer or a "set-top box" connected to a TV. Video content is typically compressed using either a MPEG-2 or a MPEG-4 codec and then sent in an MPEG transport stream delivered via IP Multicast in case of live TV or via IP Unicast in case of Video on Demand. IP Multicast is a method in which information can be sent to multiple computers at the same time. The newly released (MPEG4) H.264 codec is increasingly used to replace the older MPEG2 codec.

In standards-based IPTV systems, the primary underlying protocols used for:

Live TV is using IGMP version 2 for connecting to a multicast stream (TV channel) and for changing from one multicast stream to another (TV channel change).

VOD is using the Real Time Streaming Protocol (RTSP).

Currently, the only alternatives to IPTV are traditional TV distribution technologies such as terrestrial, satellite and cable. However, cable can be upgraded to two-way capability and can thus also carry IPTV.

NPVR (network-based Private Video Recorder)

Network Personal Video Recording is a consumer service where real-time broadcast television is captured in the network on a server allowing the end user to access the recorded programs on the schedule of their choice, rather than being tied to the broadcast schedule. The NPVR system provides ultimate time-shifted viewing of broadcast programs, allowing subscribers to record and watch programs at their convenience, without the added expense and maintenance needed for a hard drive-equipped set-top box. It's like having a PVR built into the network. In this way, services usually provided by popular consumer electronics hardware can be offered as network services. Subscribers can watch what they want, when they want, without needing yet another device or remote control.

Advantages

The IP-based platform offers significant advantages, including the ability to integrate television with other IP-based services like high speed Internet access and VoIP.

A switched IP network also allows for the delivery of significantly more content and functionality. In a typical TV or satellite network, using broadcast video technology, all the content constantly flows downstream to each customer, and the customer switches the content at the set-top box. The customer can select from as many choices as the telecomms, cable or satellite company can stuff into the “pipe” flowing into the home.

A switched IP network works differently. Content remains in the network, and only the content the customer selects is sent into the customer’s home. That frees up bandwidth, and the customer’s choice is less restricted by the size of the “pipe” into the home. This also implicates that the customer's privacy could be compromised to a greater extent than is possible with traditional TV or satellite networks.

Interactivity

An IP-based platform also allows significant opportunities to make the TV viewing experience more interactive and personalized. The supplier may, for example, include an interactive program guide that allows viewers to search for content by title or actor’s name, or a picture-in-picture functionality that allows them to “channel surf” without leaving the program they’re watching. Viewers may be able to look up a player’s stats while watching a sports game, or control the camera angle. They also may be able to access photos or music from their PC on their television, use a wireless phone to schedule a recording of their favorite show, or even adjust parental controls so their child can watch a documentary for a school report, while they’re away from home.

VoD

VoD stands for Video on Demand. VoD permits a customer to browse an online movie catalogue, to watch trailers and to select the movie he wants to watch. The playout of the selected movie starts nearly instantaneously on the customer's TV or PC.

Technically, when the customer selects the movie, a point-to-point unicast connection is set up between the customer's decoder (SetTopBox or PC) and the delivering streaming server. The signalling for the trick play functionality (pause, slow-motion, wind/rewind etc.) is assured by RTSP (Real Time Streaming Protocol).

The most common codecs used for VoD are MPEG-2, MPEG-4 and VC-1.

In order to avoid content piracy, the VoD content (the movies) is generally encrypted.

Better compression

IPTV uses a more efficient compression standard than Free-To-Air digital television, resulting in lower bit rates for streams, but higher compression may result in lower quality TV pictures in some instances.

Triple Play

Traditionally, TV has come down one wire cable TV or a terrestrial antenna, the telephone has used another (the Plain old telephone service), and the Internet has been available on either. Both cable operators and telco operators are starting to offer all three on one wire, which is more cost effective. Triple play is an expression used by service operators describing a bundle of telephony, data and video via a single connection. Triple play also refers to the combination of three services (typically Video, Voice and Internet) bundled together to entice customers to purchase all three products at a reduced rate. A quad play bundle usually includes a wireless component.

IPTV based Converged Services

Another advantage of an IP-based network is the opportunity for integration and convergence. Converged services implies interaction of existing services in a seamless manner to create new value added services. One good example is On-Screen Caller ID, getting Caller ID on your TV and the ability to handle it (send it to voice mail, etc). IP-based services will help to enable efforts to provide consumers anytime-anywhere access to content over their televisions, PCs and cell phones, and to integrate services and content to tie them together. Within businesses and institutions, IPTV eliminates the need to run a parallel infrastructure to deliver live and stored video services.

Limitations

Because IPTV is based on the Internet Protocol, it is sensitive to packet loss and delays if the IPTV connection is not fast enough.

See also

• Babelgum
• BT Vision
• Category:Internet television channels
• DVB-IPI
• Elecard IPTV Solutions
• Hanaro Telecom
• Internet television
• Joost
• LinuxTV
• Mobile TV
• Nunet AG
• P2PTV
• Tiscali TV (formerly HomeChoice)
• U-Verse
• Virtual Digital Cable
• Zattoo
• TelusTV

External links

• global internetTV Database
• ITU IPTV Focus Group
• IPTV MPEG and Quality of Experience Testing
• An Introduction to IPTV
• IPTV vs. Internet Television: Key Differences
• Assuring Quality of Experience for IPTV key challenges and solution approaches for service control and assurance
• "Does Video Delivered Over A Telephone Network Require A Cable Franchise?" AEI-Brookings Joint Center for Regulatory Studies
• Economics IPTV Development: Economic Considerations, for IPTV-SD and IPTV-HD; Comparison with HDTV, Mobile TV
• "Realtime control protocol and its improvements for Internet Protocol Television"