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Multimedia Networking in the Home: Advice to Developers (2/11/2009)

By Andreas Klauser, R&M

New technologies are crashing through the doors of homes all over the world. Multimedia gizmos and technologies such as HDTV, IPTV, video on demand, voice over IP, wireless LAN, EIB, DSL, and triple play all require networking in the home. Electricians and consumers are equally keen to find flexible and secure solutions which must also function flawlessly.

If not already the case today, a data-compliant infrastructure will certainly be needed tomorrow, if a digital lifestyle is going to be pursued by anyone. The majority of households in Western Europe now has a computer and wants to be able to use the Internet. This requires appropriate networking capability. Home office and home entertainment are the undeniable front runners at the moment, pointing to the integration of TV, radio, telephone, entertainment and information over the Internet, along with integration of A/V equipment, central storage, and decentralised reproduction of movies, images, music and documents.

Whether media convergence, digital lifestyle or smart home, a multimedia and intelligent residential landscape will only function if underpinned by a high-performing integrated network with a structured backbone comprising multimedia or generic cabling based on ISO/IEC 15018 and EN 50173 parts 1 and 4.

Standards for Cabling

A number of international and European cabling standards are already in place for multimedia system solutions, enabling communications and information exchange. These standards take future developments which cannot be predicted precisely, into consideration as best they can.

The table below lists the relevant standards for home cabling. The focus of this article is on European standards EN 50173-1 (General requirements) and EN 50173-4 (Homes). ISO/IEC 15018 Information technology – Generic cabling for homes EN 50173-1 Information technology – Generic cabling systems – Part 1. General requirements EN 50173-4 Information technology – Generic cabling systems – Part 4. Homes

European ISO/IEC standards for home cabling.

Discerning residents

As far as the cabling industry is concerned, the technically-aware tenant or house purchaser is a discerning customer. They are no longer content with the usual minimal installation comprising a telephone socket in the hallway and antenna outlet in the living room. Those far-sighted home developers therefore, who use standardised multimedia home cabling, are able to increase the attractiveness and value of their properties considerably. It makes good business sense for the landlord and for the residents, and there are many benefits: all of today’s home user IT scenarios can be implemented easily and with minimum effort; and as far as future multimedia developments offering greater bandwidth, new transmission technologies and services are concerned, modifications to the home cabling system, if ever necessary), would be easy to achieve.

Star topology is ideal

The star-configured distribution network is far superior to other network topologies because of its transparency and ease of administration. Given that, over time, most families change the use of rooms in the house, star cabling through a home distribution cabinet is also ideal, as it allows data and IT connections to be easily be reconfigured and documented - even by network specialists who were not originally involved in setting up the distribution system. This clearly highlights the advantages of a standardised architecture.

The positioning in the home of the distribution system requires some consideration. The length of cables in the distribution system should generally be kept as short as possible to avoid unwanted attenuation and to ensure the best possible signal quality at each subscriber outlet in the home. It is worth noting that these requirements also generally apply to the electric power distribution, so it would be sensible to choose the biggest possible meter and fuse box in order to accommodate the home distribution system too. Alternatively, two boxes can be placed alongside each other.

In the home distribution box

At the heart of the network sits the home distribution system that acts as the home network interface to telecom, broadband cable and terrestrial or satellite signals. Ideally, the home distribution box should be large enough to accommodated devices such as:

PABX with emergency power supply, DSL splitter.
Ethernet switch, modem, router.
Multiswitch for broadcasting via satellite.
Possibly a home relay amplifier and coax home distributor for broadcasting via cable.
Media server for music, movies and image files.

The home distribution box.

With today’s home entertainment and media offerings, it is evident that a trend towards simple input and output devices (thin clients) is emerging. Thin clients are devoid of storage capacity and lack processing intelligence. Instead, they obtain all of the contents for reproduction over the data network from a central media server as a data stream (streaming media). Thus, in principle, receivers could be installed in the home distribution system, where they are supplied with high-frequency or IP-based input signals. The clients request the desired programme stream over Ethernet, and it is supplied accordingly. Should the media server be equipped with a hard disk, it is possible to play the recording with a delay (time shifting) or at a later date. A very elegant home network distribution system could even accommodate the cable modem in the home distribution box.

Cables and sockets

A transmission path is only as good as its weakest link. Each element receiving a signal makes a contribution towards the overall performance of the transmission path. Connectors, sockets, patch panels and cables make up a transmission channel which, depending on the type of cabling used, is limited by different maximum lengths. This is illustrated in the table below, and helps explain why designing a distribution system remains an area for trained experts. Cabling ICT sym. data cable BCT sym. data cable BCT coaxial cable Topology Star Star Bus, tree, star Channel length Up to 100 m Up to 50 m Up to 100 m Frequency range Up to 100 MHz (Cat. 5) Up to 250 MHz (Cat. 6) Up to 600 MHz (Cat. 7) Up to 1.0 GHz Up to 3.0 GHz Channel class Classes D, E, F -- --

Maximum lengths for different types of cabling.

When it comes to sockets, the MATO socket is a combined wall socket for all types of services. It is a combination outlet that accommodates both twisted pair and coaxial cables, and replaces at least two single outlets.

The R&M MATO multimedia outlet with five sockets and terminals for twisted pair and coax cables.

The above image shows an example of an outlet configured for cable modems (WICLIC or F, at the top) as well as TV and radio (IEC male and female, middle). It also provides two additional RJ45 sockets at the bottom for IP and telephone connections. Up to five terminal devices can be connected to this multimedia outlet.

When working out the number of outlets throughout the home, a good rule of thumb is that the number of outlets depends upon the wall length of the room. A combination outlet should be used for each 3.75m of wall length. This will generally ensure convenient access, regardless of how the room is furnished and equipped.

Summary

In Summary, here is a list of key points to consider when planning a new building or renovation project:

* Current and future networking requirements of residents.
* Structured cabling based on EN 50173-1 and -4 .
* Layout and diameter of empty conduits.
* Capacity of the communication distributor.
* Amount and positioning of wall outlets.
* Universally usable and compatible connection technology (RJ45, coax).
* Home services to be provided: telephone, xDSL, FTTx, Sat, CATV with/without Internet access .
* Structure and regulation of other utilities (power, heating, air conditioning, light, security etc.)

Whether media convergence, digital lifestyle or smart home, it is clear that an appropriate infrastructure has to be in place. A multimedia and intelligent residential landscape will only function if underpinned by a high-performing integrated network. The backbone for this is provided by structured, multimedia or generic cabling based on ISO/IEC 15018 and EN 50173 parts 1 and 4. This is a real challenge. It is estimated that today barely 1 percent of households in Western Europe are equipped with structured cabling, but this of course means enormous potential for the installation industry.

Andreas Klauser is the System Manager for Residential Cabling at R&M, a leading supplier of passive copper and fibre cabling solutions for high-quality communication networks. For more information on this topic, Klauser’s Whitepaper ‘Multimedia in the Home’ can be downloaded from the website below.

www.rdm.com