2.3 Standardization Efforts

IPTV is a set of provider to consumer Service(s) including their business and operational aspects- Minimal scope is the secure delivery of streamed visual and audio content over a managed IP network to a consumer for display on a TV, as part of the whole N-play (voice, video, data, and more…).

Settings a standard for IPTV would be difficult at best. There are multiple areas to cover, as IPTV is a very broad subject, and the medium was not intended to transport audio and video when it was created. Moreover, some specific features of this medium allow new services while outdating some the former schemes based on broadcast.

The main advantage of IPTV, and in some aspects it is the main drawback, is the fact it relies on an existing IP network. The network operator has already deployed high-speed internet access on this network and may also have put in place other services, such as IP telephony.

Assuming the fact that the core network of the operator has sufficient bandwidth and that the access network is also suitable proportioned for carrying a video stream (these are obviously required conditions), IPTV deployment roughly consists in adding new servers, configuring the network properly and giving to the customer the proper equipment to receive and decode the stream (an IP set-top box).

All this equipment, which would ideally be bought from different providers to maintain the strategy of divide and conquer, will have to interact with each other. Standards will help accelerate implementation of the solution; as well as ensure its operation and the quality of service it will deliver. Many areas are to be covered, and without tackling the physical aspects of the system (which is hopefully already standardized). We can stand out the following standardization organizations.

DVB has had a technical ad-hoc committee (TM-IPI, IP Infrastructure). The Goal of the IPI group is to specify technologies on the interface between an IP network and retail receivers, enabling the end user to buy a DVB-IPTV receiver in any shop, connect it to a broadband network, switch it on and, without further ado, start to receive DVB services over IP-based networks. In contrast to other standards bodies and traditional broadcast methodology, it is starting at the STB and working outwards.

In the time since TM-IPI started, many groups around the world have discovered IP and decided to standardize it. The standards bodies shown are:

• DBV-IPI (Digital Video Broadcast IP Infrastructure) for Audio/Video services to be delivered to and through the home via Internet Protocol networking.
• DLNA (Digital Living Network Alliance) for the home network.
• HGI (The Home Gateway Initiative) for the standards surrounding the residential gateway between the broadband connection and the in-home network.
• ISMA (The Internet Streaming Media Alliance) for the transmission of AVC video over IP.
• BROADBAND FORUM for the standards surrounding DSL and remote management of in-home devices including STBs and residential gateways;
• ITU which, via the IPTV Focus Group, is standardizing the distribution and access network architecture;
• ETSI which, via the NGN initiative, is standardizing the IP network carrying the IPTV;
• ATIS which, via the ATIS IPTV Interoperability Forum (ATIS-IIF), is standardizing the end-to-end.
• HomeGrid for unifying the industry on a single next-generation PHY/MAC technology that can be used on powerlines, coax and phone lines.

IPTV architecture including contribution and distribution.

Nevertheless, the DVB-IPI standard does mandate some requirements on the end-to-end system, including:

• The transmission of an MPEG-2 Transport Stream over either RTP/UDP or over direct UDP. The method of direct UDP was introduced in the 1.3.1 version of the DVB-IP. handbook published by this organization. Previous versions only used RTP, and the use of AL-FEC requires the use of RTP.
• Service Discovery and Selection either using existing DVB System Information, or an all-IP method such as the Broadband Content Guide.
• Control of content on demand using the RTSP protocol.
• The use of DHCP to fix some parameters to the STB, such as network time, DNS servers, etc.

In a regular IPI infrastructure, Service Providers usually broadcast a single-programmed transport stream (SPTS), because the content is normally individually encoded but not multiplexed into MPTS. This provides more flexibility to send only the specifically-requested channel to the end user, which is very important when the access network broadband is fewer than 4 Mbit/s.