Articles and whitepapers

Why Use Internet Protocol (IP) for Audio and Video Distribution? (1/12/2006)

By Herman Cárdenas, NetStreams

It has taken a couple of years for the industry to come around, but now most major makers of distributed home A/V and lighting systems offer control interfaces based on IP (Internet Protocol) technology. And well they should. The cost and convenience benefits of control using IP, including the ability to use PCs, PDAs, and other web-enabled devices as controllers, makes sense for customers as well as installers.

Let's not, however, lose sight of an important fact. For all the companies jumping on the convergence bandwagon and aggressively promoting their prowess with TCP/IP, nearly all systems still distribute content, particularly audio, the way they have always done: via analogue, either with balanced, low-level signals to an in-room amplifier, over amplified speaker cable from a centralised system to a remote zone, wirelessly via radio frequency (RF), or a combination of these options.

One might not immediately realise the divergence between control and content by reading the ads and brochures from these companies. Many firms so tout their digital, IP-based controls that one would think they were digitising and streaming all their signals - control and content - over a home Ethernet network. With the exception of NetStreams, they are not.

The NetStreams DigiLinX Multi-Room Entertainment and Control System, marketed as the world's first completely IP-based multiroom audio/video control system for the residential and commercial markets

Technical hurdles

There are some significant technical hurdles to convey content digitally over IP. The major challenge is time synchronisation: imagine what would happen if, when walking room to room, the music was one tenth of a second out of synch. Now imagine that difference across four or five zones in a house. While synchronisation is not a requirement in common Internet applications like email or desktop streaming - not everyone needs to receive a streaming newscast at the same moment - synchronisation is an absolute necessity in a home entertainment network.

The advantages of IP

With synchronisation solved though, there are many advantages in sending content over TCP/IP, and in structuring a home A/V distribution system as an Ethernet network. Perhaps the single greatest benefit is eliminating problems with noise and signal loss, regardless of the length of a cable run or the presence of other electrical and electronic equipment. Digitising and transmitting (i.e., streaming) content over IP protects signal integrity while enabling bit-for-bit fidelity with source material including DVD-Audio and HDTV.

A second and related benefit, and one never before realised in home audio, is being able to keep signals in the digital domain until they literally reach the speaker. This would minimise or completely eliminate speaker runs - another source of noise and loss. By using IP-based digital amps, which are either co-located or integrated with an in-wall or in-ceiling speaker, analogue signal paths are kept to absolute minimum lengths.

There are additional and exciting possibilities within this scenario: designers are already working on digital IP-based amps which, based on music metadata contained in the IP stream, automatically change crossover frequencies or equalization settings based on music genre, source, or other factors. While products like this are not yet ready for market, they will be in a relatively short period. This will allow current IP-based systems to be plug-n-play compatible with this exciting near-future technology.

The NetStreams system delivers metadata and cover art without the need for extensive custom programming

Maintaining a digital signal from source to output zone also eliminates another pesky installation problem: heat build-up. Distributed amplification means there are no amp racks to cool, and no special or costly considerations for ventilation. Lower heat also means greater reliability and longevity for all equipment in the system such as source components as well as distribution electronics.

Installation benefits

Another significant benefit of systems with IP-based content and control, is fault tolerance. Entertainment systems built on network architecture distribute intelligence and connectivity and do not rely on a centralised matrix controller for system operation. Just as computer networks remain operable when an individual PC fails, IP-based entertainment systems will not be brought down by a zone-specific failure. For the installer, this means fewer urgent calls from customers, easier troubleshooting when problems occur, and faster, more modular repairs.

One compelling advantage of Ethernet-type A/V distribution is a reduction in labour and materials for installing cable: a fully IP-based system requires only industry-standard Siamese cable (CAT5/4x16) from each location. All interconnects, apart from power and legacy source components (like DVD players or non-streaming servers) are modular RJ45 jacks on CAT5 cable. Consider the advantage of using a single CAT5 to carry audio and video as well as control (compared, for example, to systems which have functionally redundant cabling to provide composite, S-video, and component connections - just for video.). The reduction in wiring not only saves time and cost, it reduces the likelihood of service problems.

The NetStreams MediaLinx A/V IP-based uncompressed video distribution solution, recently demonstrated at the 2006 CEDIA show in the U.S

Installers should also be interested to learn that with TCP/IP as a foundation protocol, they will need less-specialised programming skills, and fewer, if any, high-level programmers on staff. TCP/IP, a widely used open-standard protocol, allows for a sleek user interface without a lot of time-consuming custom programming by specialists. Currently, most companies that talk about having an IP-based interface still rely on proprietary systems requiring specially-trained programmers to modify or customise.

Future-proof

Wide-ranging flexibility, including future upgradeability, is another important benefit of an IP-based entertainment network. It is straightforward and simple to add any TCP/IP-compliant device to the network, including devices that expand network capability. Just connect them to the network. For example, someone with an A/V distribution network based on TCP/IP could instantly add lighting, home automation, and/or security features simply by plugging in the appropriate device, including third-party products. Without a common protocol, devices would require customised programming for installation and operation.

Conclusion

For installers peering into the crystal ball of digital convergence, there is an unquestionably strong future for IP-based products and technology due to the Internet becoming a common denominator for global communications. With the worlds of computer networking and home entertainment drawing closer together and a greater number of network technicians entering the home systems market, popularity and preference for true IP-based home technologies will grow steadily and rapidly.

While there may always be markets for proprietary products and technology, systems based on open standards typically create the greatest market potential and business opportunity.

Herman Cárdenas is the founder and chairman of the board of NetStreams LLC, manufacturer of residential and commercial networked entertainment systems based on Internet Protocol (IP) technology.

www.netstreams.com