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Installation Europe Magazine
September 2007
There’s a Lot on the Line
Preserving the quality of data on its journey from source to end-user means important considerations about cable and connectors. Joy Zaccaria reports on the latest developments, in particular the rise of converged IP infrastructures
When selecting cable for an AV installation, communication between integrator and client – to determine what sort of technologies are going to be connected and what sort of data will be sent over the lines – is key. With new formats and gear developing at lightning speed – mostly with varied protocols travelling over the same IP networks – anticipating future unknown possibilities is mandatory.
Future-preparedness means starting with a holistic approach at the outset and considering technologies that are gaining prevalence now. “Look at the installation cost in terms of labour and project management versus cost of material,” says Rajesh Sinha, chief technical director for Bailey Teswaine. “It may be worth putting in dark fibre or cables you aren’t going to use from day one. They can be switched on at a later date rather than having a refit when bandwidth is tight.”
Today’s AV market has clients demanding more than straightforward data networks. In a world of converged installations in stadiums, office buildings and churches, the whole infrastructure is on IP. When telephony, CCTV systems, and connection for Wi-Fi nodes are all on IP, there’s a lot riding on those lines.
With many systems on one network, Sinha says: “It places more of a demand on the network infrastructure, but it means that you’re not investing in four or five different systems. You’re putting in a very robust IP infrastructure from the outset that can support multimedia apps and conferencing, along with traditional data applications.”
The customer appreciates the benefits of managing a much simpler infrastructure on one core network as opposed to three or four for AC, heating, lighting, and so on. “We sit with our customers and ask what they’ll be using the infrastructure for,” Sinha remarks. “What are the growth plans? Have you thought about putting other systems on the infrastructure?”
In environments where clients are looking to use multimedia, videoconferencing and IPTV, Bailey Teswaine is providing signals to multi-unit dwellings over an IP infrastructure. “That’s where 10Gb Ethernet infrastructure and fibre get more important,” says Sinha. Costs for these two new cabling technologies are within reach. “Typically a lot of the cost is around installation and not necessarily the raw materials,” he points out. “We advise our customers to lay more than they need in the first instance.”
Dug Guthrie is the technical director of VDC Trading House, the main trading agents for Van Damme cables. He sees the more forward-thinking establishments as mindful of moving to 10Gb Ethernet. “Rather than install a Cat-5e network within an audio post production or a video post production environment, they are installing Cat-6a for 10Gb Ethernet, even if they’re only running Cat-5e networking at the time.” 10Gb Ethernet runs over Cat-6a cable where the ‘a’ stands for ‘augmented’. Cat-5e (‘e’ for ‘extended’) is typically for gigabit Ethernet, which is the predominant form of networking at the moment.
Bailey Teswaine gets requests mainly to flood wire. “We don’t have customers coming back to us saying, ‘you put in too much cabling’,” says Sinha. “Often it’s the flipside. A customer didn’t realise they were going to move this department around and requests more data points.”
With flood wiring, data points are installed on a grid system across the building at the outset to provide the flexibility to move people and walls around. “Customers are also asking for data points in the ceiling and non-traditional spots for IP cameras, temperature sensors and environmental sensors because all these devices are now IP enabled,” says Sinha. “Generally, if there’s a data point available, it will be used very quickly. That’s when Wi-Fi can be useful.”
A great complement to wiring is wireless. “In a lot of cases, people are putting data points in a guest area or meeting room,” says Sinha. “When you have meeting rooms in a period building where drilling through 16th-century oak isn’t necessarily preferable, it can be useful.”
However, there are certain situations that Wi-Fi wouldn’t be a successful option. “You wouldn’t put Wi-Fi in as a mission-critical app,” Sinha points out. “You certainly wouldn’t use it for IPTV where the bandwidth requirements are massive.”
Cable route planning
Part of the consultation process is mapping out the cable runs. The path of the cable can affect the content running through it. “You need to consider the bend radius of the various types of cable,” says Guthrie. “Where you might put a corner in trunking or in a cable tray, make sure that you are not exceeding the recommended bend radius of the cables.”
That’s becoming more important when working with highfrequency digital-video signals such as HD SDI. If a cable is deformed, the characteristic impedance of the cable could be changed at that point, resulting in reflections. “In planning AV cabling routes, if you happen to encounter any mains cable installations in your cable route, you want to try and cross those mains cables at 90° and not run parallel to them,” says Guthrie.
Future upgrade costs can be minimised by making the right compromise between the functionality necessary of the cable and its cost. “When installing a digital coax, I always advise people to spend an extra 15 or 20 pence per metre of cable and put in the best one they can,” says Guthrie. “Within digital imaging, 1080p is becoming the norm as an HDTV resolution as opposed to 1080i.”
In the video world for long distances, Sommer Cable’s Vector Plus 1.2/5.0 transmits video signals for up to 1km or a running length of 60m, and is used as an SDI or an HDTV cable. Sommer says its SC-Classic Control puts an RG 59- video cable and two additional insulated wires in a tough PVC jacket to connect monitors easily and for a reasonable price.
VDC is selling more digital coax now than analogue. “Coax is used on the whole for installations, certainly,” says Guthrie. “More AES twisted pair are used than analogue twisted pair.” Clients look to install cables that deal with both digital and analogue signals so rather than put an analogue twisted pair in an installation for audio, people tend to put in an AES twisted pair – digital audio pair.”
A cable that performs very well electrically can be used as a twisted pair for DMX and RS 422 and RS 485 control protocols. “You’re getting a lot of potential functionality out of putting one twisted pair in as opposed to putting in a twisted pair for analogue and another one for digital and another for DMX,” he says. The same applies with video coaxials.
With so much running over one network, composite cables often fit the bill. Van Damme offers a cable that has six coaxes, four digital twisted pairs and three high-gauge tracer wires all contained within one jacket. “You could pull that one cable and out of it you could be running three channels of digital audio, a channel of DMX lighting control, VGA and composite video and RS232 all in one 15mm cable. It’s always easier to pull one cable rather than two,” says Guthrie.
New cable technology and fibre hybrids
Clients look to install cables with higher performance. According to Guthrie, there’s a tendency among all precision video cable manufacturers to move to a gas-injected dielectric coaxial. “Everybody is trying to get the best possible attenuation at the very high frequencies required for the transmission of HD SDI.”
Fibre and half-fibre hybrids like SMPTE-311 hybrid fibre optic/copper camera cable are being used more. “We have supplied cable to a few major new arenas, particularly in the Middle East and for the Asian Games,” says Guthrie. “Everybody seemed to be installing fibre camera cable. Whether or not they terminated it, I’m not sure. But they’re laying it in for future use. Long distance, high-definition signals just won’t go down copper. You need to use fibre.”
A number of products have recently appeared on the market that are designed to reduce installation time. OpticalCon from Neutrik is a hybrid fibre-optic connection system and has been extended by additional cables and a field repair kit. The cable range has been broadened to five cable versions consisting of two two-pole, one four-pole and two hybrid cables. Most robust fibre-optic connection systems are proprietary and can’t be repaired on site when a problem occurs. However, the OpticalCon connection system is based on regular LC connectors, so it’s possible to use conventional field-installable LC connectors to fix a connection in the event of an emergency.
In the interest of saving time on the installation site where VGA or RS-232 controls are used, BTX Technologies has introduced a range of solderless connectors – the MaxBlox EZ Termination System. Installers can terminate an HD15 or a DB9 with a screwdriver and mount it on a cable or into a wallplate in less time than it would take to solder.
Since Ethernet has found its way into the audio, network and control field, Neutrik has addressed demand for qualified connectors with the development of the EtherCon series. This offers a rugged metal housing for RJ45 cable connectors, which protects the connector against mechanical load, and features the patented Neutrik chuck type strain relief and a separate locking.
In order to meet the rising requirements of data volume, transfer rate and bandwidth, Neutrik developed a weatherproof (IP54), rugged and stage fit Cat-6 version of the RJ45 Ethernet connector. The D-size housing of the Cat-6 EtherCon chassis connector is made of metal, as is the cable connector carrier, whose chuck type strain relief holds the cable securely and its PushPull locking avoids accidental unplugging.
Building codes
Health, safety and environmental considerations are increasingly dictating aspects of cable specification and disposal. For instance, in the UK and spreading out more in Europe, buildings increasingly require cables to have a lowsmoke zero-halogen jacket material. “Canary Wharf is a good example,” says Guthrie. “We’ve supplied lots of cable in the past for installations in Canary Wharf such as the HSBC Bank building and Lehman Bros’ European headquarters. There’s a very stringent requirement that the cables have a low-smoke zero-halogen jacket material.”
The Waste Electrical and Electronic Equipment (WEEE) Directive restricts disposal of electrical waste throughout the EU. If a contractor is responsible for disposing of electrical waste, it is legally bound to do so in a sustainable way by recycling the copper and PCs.
“Sustainability is becoming more of an issue,” says Sinha. “Taking copper out and recycling it is key to what we do now as well.” Bailey Teswaine is one of the first IT companies to have achieved the environmental accreditation of ISO 14001. “We’re very forward thinking in terms of being carbon neutral.”
Legacy cable is not just a museum of technology. Those old cables can be reused. “We work a lot in the hospitality space, providing cabling infrastructure for the likes of Novotel Hotels,” says Sinha. “The phone line is going up to individual hotel rooms and can have an ADSL across that in the same way DSL is being rolled out to homes across a pair of copper wires.”
The typical lifetime of cable is about 25 years in an optimal environment but the lifetime of technologies is much shorter. “A PVC cable outside in the sun would crack within 10 to 15 years,” says Guthrie. “But if you run it under the eaves and it’s in the shade, protected from the rain, there’s no reason why it couldn’t stay up there for 30 years.” In general though, cabling is ripped out more because the technology has changed, not because the cabling is failed.
“We factor 25 years as being the lifespan of a structured cabling infrastructure,” says Sinha. “When we have PFI [UK private finance initiative], big hospital projects and government projects where we’re asked to manage an infrastructure for the life of the building, we factor in a refresh cycle of 25 years.”
Resilience
In this converged space, putting voice and data systems on a single infrastructure requires resilience. “A few years ago, people relied on the voice system being there all the time,” says Sinha. “If email went down for 20 minutes, no one cared. But if you can’t make a phone call, people get angry. We’re saying, ‘combine the investment you would have made in the voice system and data system and build a lot of resilience into your network with monitoring so you know it’s there when people need it.’”
Case study: VDC supplies cable for new church
CRYSTAL CLEAR AUDIO, a company that specialises in high-quality AV installations for churches and schools, has installed the audio, video and stage lighting systems into a new church in Whitstable, south-east England.
The entire installation at the Seasalter Christian Centre was cabled using Van Damme microphone, speaker and data cables, which were supplied by VDC Trading, along with all of the connectors for the project.
The Seasalter Christian Centre is an Anglican church that can accommodate a congregation of up to 350 in its main hall. The new building also includes meeting rooms and kitchen facilities.
says: “The AV and lighting installations were very highly specified in order to meet the demands of the congregation and of external customers who use the hall and meeting rooms during the week. I used Van Damme cables because they are reliable and rugged. This installation demanded that kind of quality.”
He continues: “The church installation market is highly specialised and does present some usual challenges, particularly in terms of acoustics. Because this project was a new build, we were able to get involved at a very early stage and specify exactly what we needed in terms of cabling. In all, it took five months for us to complete the installation.”
The Seasalter Christian Centre’s audio facilities include Sherman speakers, QSC amplifiers and a 32-channel Soundcraft LX7 Mk2 console. The full playback computer and video facilities include two Hitachi CPX1250 projectors and two large screens that measure 2.5m in width
Case study: Bailey Teswaine creates ‘virtual’ office environment
COMMERCIAL LAW FIRM Cobbetts contracted Bailey Teswaine to install a £140k IP telephony solution, which integrates three sites to create a single ‘virtual office’. It also accommodates planned office moves and support for its flexible working drive by offering teleworking facilities for its staff and partners.
700-user IP system at the UK legal experts’ existing Leeds and Manchester bases, as well as at its newly acquired Birmingham office. The technology offers teleworking benefits and allows Cobbetts to implement an effective hot-desking facility, therefore making best use of its available office space.
All three sites have access to fully converged voice and data technology with applications that can be easily updated or added to over time. The new system creates a single ‘virtual office’ by linking all three locations with a single telephone system and vastly improved resilience. This allows a consistent and improved level of client care regardless of the solicitor's location when the client calls.
John Parkinson, account manager at Bailey Teswaine, comments: “We are proud to be working with Cobbetts to ensure it has the best technology not only to help it perform in an increasingly efficient way, but to provide its people with the facilities to work flexibly.”
Michael Shaw, managing partner at Cobbetts, says: “Through our mergers in Leeds and Birmingham, we have grown to be a Top 40 firm and it is vital that we employ the best technology to support both our clients and our own people.
“In the longer term, another key benefit to us will be the potential to integrate the telephony infrastructure with our practice management system. This will give staff faster and easier access to important information such as client files and individual case details.”
www.baileyteswaine.co.uk
www.btx.com
www.neutrik.com
www.sommercable.com
www.vdctrading.com