Today’s stadium development has to be so much more than just a grandstand and a pitch: An average stadium these days might incorporate conference or meeting room facilities, executive enclosures, retail outlets and all manner of public amenities. The challenge for designers is to provide built-in adaptability and flexibility to cater for all these different needs, both now and for a long way into the future. The design of building infrastructure too has had to evolve to meet the demands of the modern era. Stadium security, public safety and facilities management systems have all become exceedingly complex. Add to this the management needs of commercial enterprise within the building via Electronic Point Of Sale systems (EPOS), the management of meeting room facilities and a myriad of other communication and business functions and it’s not hard to see that the whole business of distributing and managing services over an area as wide as a modern stadium development has become a very complex affair indeed.
But over and above the actual business of managing the facilities, meeting or exceeding the expectations of visitors is of course, crucial. The days of garbled announcements emanating from hissing, poorly positioned speakers and low-resolution, clumsy scoreboards are long gone. Today’s audiences demand a much higher quality, media rich experience. Zoned audio, advertising promotions, even the latest generation of digital signage and scoreboards all require audio-visual content; Information from statistics servers, crowd announcements, and even data from remote sites needs to be routed and managed. And it’s not just the physical visitors that need to be supported in this way. A striking vision of the level of sophistication now being employed in the management and distribution of media and data is the world famous Wimbledon tennis Championships.
While some 470,000 visitors attended the 2002 tournament, the Wimbledon website received over 2.6 billion unique visits from 165 different countries during the two week competition. As well as statistical information, visitors could download a real-time scoreboard for their computers which was linked directly to the scoreboard at Wimbledon. At one point during the 2002 finals, 168,811 such scoreboards were in simultaneous operation. This year, visitors to the club were even able to receive live match updates on their hand-held wireless devices via a Wi-Fi LAN installed for the purpose. The entire network behind all these services is provided by IBM, whose involvement covers just about every aspect of data acquisition, management and delivery. IBM employs specially-trained tennis experts for its data entry teams, who record every service, point scored and winning or losing shot made using notebooks and PDAs. Data is collected and forwarded into a central database for immediate distribution to a number of key services both within the Grounds and around the world including the Wimbledon Information System (WIS), the Championship Information Services (CIS), the Official Web site http://www.wimbledon.org, SMS services, and large match information displays located around the Grounds.
Companies like IBM have long understood the importance of a resilient and flexible network infrastructure. It is the network infrastructure that is perhaps the most crucial factor determining the adaptability of any data system in the long term. Whilst hardware can be replaced or upgraded in response to changing demand or technological advancement, the cabling network which connects it all is usually a much more permanent affair. It is no longer good enough to build for today because, these days, tomorrow inevitably arrives much sooner than anticipated. Dedicated distribution technologies for each separate system do not allow the kind of flexibility required: Integrated solutions need integrated services.
At the dawn of the information age, data and voice communication operated via completely different transmission systems. Disparate transmission media means different types of hardware, cabling and infrastructure, added complexity and expense. Until comparatively recently, audio, video and building management signals were treated in the same way. But just as in the IT world, a universal distribution medium is fast becoming the norm for both data and AV content.
Cheap, unshielded twisted pair (UTP) cable capable of handling Ethernet data rates has been available since the late 1980’s. For reasons of economy and ease of handling , UTP has become the medium of choice for data communications, the “Cat5” standard UTP becoming virtually ubiquitous in local area voice and data applications. Together with the use of fibre-optic for longer-haul connections between floors or different buildings, these systems are generally referred to as structured cabling schemes.
The first commercial building cabling standard to define the structured cabling concept was released in 1991 under auspices of the Telecommunications Industry Association/ Electronic Industries Association (TIA/EIA). The original TIA/EIA 568 standard forms the basis of the latest international standard, ISO/IEC 11801. As well as defining in detail the media and topology of the structured cabling system, one of the primary aims of TIA/EIA 568 was to develop a uniform wiring scheme which supported multi-vendor products and environments. This proved to be a far-reaching development because this meant that it was now possible to plan and pre-install communications wiring in buildings without any prior knowledge of the products that would eventually use it – a cabling system which was useable by any network device and therefore very flexible.
Today, the TIA/EIA 568 and its international derivative ISO/IEC 11801 provide strict performance criteria which any structured wiring scheme must adhere to. These standards are well understood by building contractors – companies like CCI Ltd – who specialise in structured cabling systems. Economies of scale make it cost effective to use a single specialist contractor like CCI, to install everything instead of several specialist contractors, and the comparative cheapness of the cabling means that “flood-wiring” – installing cabling throughout an area even if there is no specific requirement at that point in time – has become accepted practice. “More end users are coming around to the idea of flood-wiring because it’s much cheaper in the long-term”, says CCI’s Ian Blackman.. “Labour is by far the biggest element in the cost”, says Ian. “In a new build, you might be paying €55 – €85 per outlet. This rises to something like four times that for a retro-fit.” Clearly, the more systems than can utilise this common structured scheme, the better.
In recent years there has been a quiet revolution going on in the audio-visual world, no less far reaching in its implications than the convergence of datacomms and telecomms was in the ‘80’s. That revolution is the growing usage of standard data networks to manage audio-visual systems. Much of the AV equipment in use today – projectors, touch panels, room controllers – is now IP addressable meaning that control of these assets occurs over the same network infrastructure as the in-house computer network. For applications like a stadium, where equipment can be spread over a wide area, this brings obvious advantages as an operator sitting at a terminal in a central control room can now interrogate and control any piece of equipment on the system. This seemingly simple concept has had a huge impact on the AV world as audio-visual assets are increasingly seen as falling within the realm of Information Technology. Even at a hardware level, AV equipment is increasingly incorporating networking technologies. For example, there are now video projectors with built-in file servers that are as much computer as they are projector. The next step – employing structured cabling systems to route AV content – seems logical and inevitable. But delivering truly high quality audio-visual content over a standard structured cabling system still has its technical limitations.
Cat5 wiring systems were designed for digital signals and so some technical problems exist in using it to distribute analogue. But its modest bandwidth requirement allows audio signals to be transported in the digital domain – the format for which UTP was originally intended – and has allowed the use of audio networks to become firmly established. Barry Revels of Canford Audio comments, “There has been a big increase in the use of twisted pair (UTP) in audio installations: That increase has been exponential over the last two years”. Barry agrees that products like BSS Soundweb are having a big impact on the install market, and it’s not hard to see why. Multiple channels of digital audio, and in some cases control signals too, can share a single low-cost Cat5 cable delivering self-evident advantages in terms of the cost and the ease of cabling large-scale installations like stadiums or passenger terminals. Not to mention the inherent flexibility of a structured network approach and its ability to easily adapt to different applications and configurations. The audio system installed in London’s Millennium Dome, for example, utilised around 4000 channels of audio and would have been all but impossible to achieve using conventional analogue equipment. But using BSS’s Soundweb system, signals could be routed to and from any part of the Dome – all easily managed from a central control PC. Soundweb is just one example of a new generation of audio systems designed to utilise the network infrastructure. The Soundweb network uses its own transmission protocols and is capable of bi-directional transfer of 8 channels of 48kHz digital audio over Cat5.
And yet, advanced though systems like Soundweb and Vadis are, they still do not represent the true union of AV and IT infrastructure. The reason is that both systems still require a dedicated network infrastructure, separate from any other transports which may be needed like Ethernet networks, for example. But systems are now available that breach this last remaining physical barrier to true integration. CobraNet from Peak Audio is an audio network solution utilising Ethernet as it’s transport medium, allowing digital audio to share the same network as data. Ethernet works by splitting data into discrete chunks which are routed to specific destinations via repeater hubs or intelligent switches. The key to CobraNet is its ability to route time-critical data packets like real-time audio through the network ahead of lower priority network traffic. While it might not be appropriate in every case, adopting the Ethernet medium brings some significant advantages, aside from saving money on cables and cabling costs. The industry providing cost-effective Ethernet-related hardware such as switches, hubs, WiFi radio links etc., is vast and well developed. Ethernet’s “star” wiring configuration increases system reliability and flexibility. Ethernet also allows for the creation of “Virtual” networks or VLAN’s which allow segregation of services over the same physical connection.
CobraNet was the system installed in VfL Wolfsburg’s Volkwagen Arena at the end of 2002, one of only two football stadia built in Germany for decades. The €53m project utilises nearly 100 Kling-Freitag speaker enclosures distributed around the stadium to achieve the recommended sound level of 105dB at all seats in the arena, with a tolerance of just +/- 3dB. The audio system is driven by Crown amplifiers fitted with network cards and individually controlled over the Ethernet network using Crown’s own TCP-IQ software, operating via standard HP Procurve series network switchers.
But while audio distribution over structured cabling is becoming widely accepted as the preferred solution, the distribution of visual content in this way has more technical limitations. The reason is that a digital video signal requires a much higher rate of data transfer – rates that are not generally possible over conventional cabling systems. But, while digital video over the network maybe yet to materialise, even here the structured cable concept is being employed to good effect.
“We’ve seen a steady deterioration in the quality of video over co-ax”, declares John Stephenson, managing director of Studio Systems Ltd. “UHF distribution over coaxial requires modulation and demodulation which degrades quality. Our aim is to re-introduce quality, and Cat5 is the ideal medium for that”. John was one of the first people to became involved with developing high quality video distribution over UTP whilst working as a senior design engineer at the BBC. After leaving the BBC, John formed Studio Systems to develop commercial UTP video applications. “We’ve been involved with UTP for over ten years now”, says John. “Initially we worked in banks and dealer rooms, but applications are now much more widespread, and include training facilities and even supermarkets.” John is a strong advocate of the advantages of video distribution over twisted pair: “The beauty of Cat5 is that it’s all there: With builders and architects now routinely flood wiring, you have the ability to patch signals anywhere you want without having to re-wire – plus, of course, the advantage of higher quality”. The idea of high quality analogue signal distribution over twisted pair is not new. But the quality of video over UTP has advanced to the point where it is now a serious contender to coaxial: “Signal quality is getting better and better all the time”, confirms Paul de Graca of Extron. “We ran a test recently between coaxial and UTP, running a 1280 x 1024 signal over 150m; you couldn’t tell the difference between the two”. So does this mean that Cat5 offers a truly universal AV – IT infrastructure? Not quite: Because as Paul points out, for the moment at least, video “can be distributed over Cat5, but it’s still an analogue signal”.
“And at the end of the day, Cat5 was designed for IT systems, not video”, continues Paul, citing various quality problems which can occur. Special media-grade cable is available, but this is expensive and doesn’t work well with data applications. This illustrates the point that although the concept of a pre-installed universal cabling structure is an attractive one, the current reality falls a little way short of the mark. But inevitably the trend within digital networks – the real driving force – is toward higher bandwidth systems. The emergence of gigabit Ethernet calls for a higher specification network infrastructure. While some Cat5 installations will support gigabit Ethernet, the recommendation now is for Cat5e cable, which at 200MHz, is rated at twice the transmission capability of Cat5. Now, even higher specification cables are emerging. Cat6 (ISO Class E) is designed to support 200MHz and above, while the Cat7 (ISO Class F) standard will be rated at up to 600MHz. Again it’s crucial to remember that these systems are not designed to carry analogue signals. Problems like crosstalk and interference could cause some unexpected headaches for AV installers attempting to pass analogue signals over these systems. Nevertheless as John Stephenson says, “There’s still a lot of life left for analogue (video) over copper. I’ve yet to see really good and affordable IP video sources, although I’m sure that it will happen.” But network speeds are increasing year on year. Just this month, Fujitsu announced the development of a 12 port, 10 gigabit per second Ethernet switch on a single chip. It is perhaps only a matter of time before the last technical barrier to true unification is breached.
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