IPTV Frequently Asked Questions
A large portion of the content here was contributed by Alexander Cameron, Managing Director, Digital TX Ltd. Digital TX Limited is a provider of technology and consultancy solutions for interactive digital television and broadband media.
What is IPTV?
Internet Protocol Television (IPTV) is broadcast-quality television and/or video signals that aredelivered to subscribers or viewers using a broadband connection over Internet Protocol (IP). While IP stands for Internet Protocol, it does not actually mean the television content is streaming over the Internet. IP is simply the same method, protocol, or technology that enables you to access the Internet and IP-delivered television content is utilizing the same technology for delivery.
 IPTV operates on a different premise than traditional satellite orcable television in that only selected programming and on-demand content are delivered to the consumer. With Satellite and cable, all channels are being pushed all the time to the consumer's home rather than a per-selection basis. IPTV's ability to provide two-way communication (you request a program from the TV guide and the program is delivered to you) offers true interactivity for the customer with the environment. HDTV, movies, past TV shows, and all other content can be distributed on demand and service providers can tailor the requested content and advertising based on customer preference.
IPTV also offers such potential as on-demand video gaming and because it is using your broadband connection, it can interact with other Internet services such as Voice over IP (VoIP). Consumers may have caller ID displayed on their television. The potential is truly unlimited.
When will I be able to watch it?
IPTV rollouts are taking place around the globe. Multimedia Research Group, Inc. is projecting global growth from 3.7 million subscribers in 2005 to 36.9 million in 2009, the report also forecasts subscriber revenue growth from $880 million to $9.9 billion in 2005-2009.
Check with your local telephone or cable company to see if they are working on offering IPTV.
Who is offering IPTV?
Verizon has already begun rolling out their IPTV initiative, called FiOS, up and down the east coast and in Texas. SBC and Bellsouth have initiatives of their own. There are smaller telecom
companies rolling out their own services across the U.S.
In Europe, IPTV services already in place include Fastweb in Italy, HomeChoice in the U.K.,
MaLigne and Free in France, and Telefonica in Spain.
In Asia, you can choose from Chunghwa Telecom in Taiwan, PCCW Ltd. in Hong Kong and Softbank/Yahoo BB in Japan.
What is the minimum bandwidth you need for full screen TV and video?
Typically video broadcast as MPEG-2 (the current standard for digital television and DVD) takes 4-6Mbit/s, whereas newer, advanced codecs (e.g. MPEG-4 H.264, VP6, VC-1) are designed to consume 1-2.5Mbit/s. Generally, the lower the bandwidth, the lower the video quality. It is possible to deliver video at well below these levels if the environment is optimal – e.g. the picture size is smaller or the content is fairly static.
What happens if the TV is in a different room to the broadband gateway/router?
Short answer: use HomePlug. There are three options for solving this problem, as all set-top boxes require a simple Ethernet connection for basic operation. The first is to place your router next to the TV. The second is to provide Ethernet cabling from wherever the router is (usually the hall or study) to the TV. The third, and most elegant solution is to use HomePlug (14-200Mbit/s) broadband over powerline technology to extend the connectivity to every room in the house. In this scenario, 1 adaptor would be plugged in next to the central router, and the other by the television, invisibly connecting the two.
Can other people in the same house watch video at the same time as the main user of the connection?
Yes. Most modern analogue and digital television platforms support some form of 'multi-room' capability as they use the broadcast model of transmitting a whole spectrum of channels at once, instead of one at a time as IP delivery does. It is possible to stream (multicast) the output of a central set-top box across the network to other devices. The ability to receive different channels in separate rooms is dependent on whether the home broadband connection has enough bandwidth to support it. In most cases, ADSL2+ (or 12Mbit/s +) technology is needed for this functionality, along with strict quality of service. For example, three rooms watching three different channels of live TV encoded at 1.5Mbit/s would need 4.5Mbit/s bandwidth, with an additional guarantee of 1Mbit/s to compensate for network overhead and transit problems.
Do you need multicast capability, and what are the implications for our network?
Yes. IPTV channels can only be delivered over IP networks as multicast, so if you want to deliver live television, your network (from DSLAM to peering hub access) must be multicast-enabled from end to end. Live TV cannot be delivered by unicast, and multicast also enables the most efficient delivery of video data and the smoothest channel changing speed. For example if you wanted to offer 100 live TV channels in 4Mbit/s MPEG-2, you would need 400Mbit/s backhaul multicast bandwidth. Using dynamic technologies such as PIM can help to reduce network overhead by only relaying the channels that have been specifically requested.
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