Articles and whitepapers

Networking for Now and the Future (1/11/2006)

By Peter Aylett, CEDIA

Let me start by dispelling a myth - there is no such thing as 'future proofing'. Selling this concept to a customer with regards to networking is tantamount to saying that as long as the house still stands, the infrastructure that you install will be capable of carrying whatever information might be around in 25 or 50 years time. If you take the view put forward by Ray Kurzweil in his book, The Singularity is Near - When Humans Transcend Biology, by then human intelligence will be supplemented, and even transcended by artificial intelligence. Who knows what the bandwidth requirements will be for data flowing in, out and around an average household by then?

Bandwidth

Bandwidth is the key for defining how we design and implement networking infrastructure both now and in the future. The technology that currently puts the greatest demand on network bandwidth is streaming high-definition (HD) pictures and sound. An HD stream is around 15Mb/s, and with overheads, you are looking at around 25Mb/s. This is well within the capabilities of a Fast Ethernet (100Mb/s) network running over a Category 5 infrastructure, but factor in multiple streams over one link, and Gigabit Ethernet (1Gb/s) becomes necessary.

Gigabit Ethernet can be successfully run over category 5E infrastructures. You will note that I am talking about infrastructures and not just cable, as a category rating is for the complete 'channel', including the sockets, plugs and flyleads, as well as the properly-installed and terminated cable. The next step up from Gigabit Ethernet is 10 Gigabit Ethernet. To give you an idea of how fast this is, you could transfer an entire DVD in under 30 seconds.

10 Gigabit Ethernet requires an augmented Category 6 channel (ANSI/ TIA/EIA-568-B.2-10 Augmented Category 6) to operate over the 30 metres that standard Category 6 will give you. As well as a new cable type, the new standard will mean new sockets and plugs. The proposed standard for Cat6A is the GG45, and this will create challenges in our industry until the manufacturers of architectural fittings catch up and start making sockets to the new specifications.

The GG45 connector proposed for Cat6A cable

The fibre advantage

So far we have only looked at copper, but there are some exciting developments around regarding fibre for the home. WDM (Wavelength Division Multiplexing) is a technology that allows more than one wavelength of light to be used on Single Mode fibre. This will give us the option of almost limitless bandwidth over fibre cables that have the ability to run multiple services at once. For instance, you could run a 10 Gigabit Ethernet connection in full duplex concurrently with a high-definition stream from an HDMI-to-fibre converter. So, as far as bandwidth for the future is concerned, the new residential Single Mode fibre solutions look to have the advantage.

Wavelength division multiplexing over fibre cable

Wireless networks

Wireless networks are continuing to improve. In addition to addressing issues of bandwidth, lots of work is being put into QoS (Quality of Service). This refers to a network's ability to pass IP (Internet Protocol) packets across a network within desired latency periods without dropped packets, delay, jitter, out of order delivery or error. This is becoming increasingly important as a 50ms delay in a packet arriving, while having no perceptible effect on an application such as Web browsing or email, would have a disastrous effect on a video conference or streamed video.

The latest standard, 802.11n, addresses these issues as well as promising 200Mb/s throughput, which will be enough for the holy grail of wireless - HD video streaming. Indeed 802.11n's theoretical maximum is 540Mb/s, but as with current standards, actual throughput never reaches the theoretical maximum. In 2007, Apple will be targeting the living room with a media adaptor that is expected to use 802.11n, but it is worth noting that the IEEE does not plan to ratify the standard until 2007, with the final standard being published in early 2008. It is also worth remembering that while 802.11n will have the option of using the 5GHz frequency band, to retain compatibility with legacy devices, networks will still have to run at 2.4GHz.

Builders and developers especially, should also be aware of the Faraday cages that are being inadvertently built in many homes using foil-backed plasterboard that is earthed through metal back-boxes! While these may not noticeably interfere with less bandwidth-intensive control applications such as heating, lighting and other low data rate applications, they can cause problems for wireless media distribution.

So, even though wireless technologies continue their inevitable march to replacing cables for data, for the time being, we need to design a cable infrastructure to support an effective wireless media network. Indeed the analogy that 'wireless' is really 'cordless' still holds true - it gives you the freedom to use elegant portable devices that are not constrained by cables.

Conclusion

While the options available to us in the next few years may be staggeringly different to what we are installing today, with some careful planning, we can be future ready. As an industry however, it is time that we started to become network engineers and add those skills sets to our armoury alongside those audio and video skills that our laurels have been resting on for the last ten years.

Peter Aylett is the Education Manager for CEDIA, the Custom Electronic Design and Installation Association for companies specialising in planning and installing electronic systems for the home - typically media rooms, single- or multi-room entertainment systems, home automation and communication systems, as well as integrated whole-house subsystems providing control of lighting, security and HVAC.

www.cedia.co.uk