Wireless Access Control Systems
♦ Wireless access control systems increase the size of the access control industry while posing new challenges for security installers.
Reliable communications between doors and controller are the key to access management systems. One of the great things about wireless access systems is that the information they pass on to controllers and head end management solutions is not always required in real time. This element of distributed intelligence gives wireless access control systems a little more latitude in terms of performance when compared to wireless alarm systems.
Another benefit wireless access systems are bound to catch a ride on is the advent of capable wireless LANs. Over time there’s no reason why a miniaturized wireless NIC could not be employed to carry access control data to the nearest wireless router where it can be passed on to the relevant control module or workstation.
When you think wireless access control it helps to think wireless alarm systems – that’s because wireless access solutions are modular in the same way wireless alarm systems are. The lock, reader, power source and transmitter/receiver are all housed in a single case that’s incorporated into door hardware and installed inside the door itself.
Being integrated in this way means that the beauty of wireless access systems is their speed of installation – there’s also an elegance to any access solution that avoids a network of door controllers along with dedicated LAN and bus solutions usually required – especially when there are huge numbers of access-controlled doors required – as you might find in a school or a hotel.
In a building with a comprehensive wireless LAN, it’s possible to install hundreds of wireless access doors with the door/reader modules linked to the LAN via wireless VPNs on each floor, then ported onto the cabled network allowing them to communicate with a single workstation. If you have the necessary network reliability, it’s simple yet highly modular – the epitome of efficiency and distributed intellect.
Of course, many wireless solutions have their own way of doing things – think SALTO or Aperio – with data making its way to the management system in a number of different ways.
One of the great beauties of wireless access control is that it cuts down the amount of time required at the door. It might take an installation team an hour to install and electric strike – longer if the door frame and door controller pose problems.
And when you talk access control, it’s not just a lock that needs to be installed on a door. There’s a strike plate, a reader, a door position switch, a power supply (or power cabling from a nearby controller) and door alarm sensors. Once all this hardware is in place, everything has to be wired up and looped back to the door controller.
Conversely, when you’re putting in an integrated wireless access control lock, all these components are incorporated inside a single lock body and once you installed this lock, you’ve covered all the necessary bases.
A vital aspect of a wireless locking solution is ensuring there is low battery indication in advance of battery failure. Manufacturers claim very impressive economy figures for their wireless locks – more than 50,000 reads and up to 5 years lifespan is normal. Battery replacement needs to be included in maintenance programs.
Depending on the size of the size and the wireless comms technology, the time and effort saving don’t end at the door – they go all the way to node zero. Instead of locating door controllers at the long end of star cabled configurations, you can locate your wireless door controllers (in the case of a dedicated wireless access LAN) in the access system cabinet, linking them to the main panel over a drop length of RS-485 LAN.
While the concept of on-door wireless NICs is futuristic, alarm and access panels like the DSC Maxsys already allow 16 wireless doors to be controlled from the control panel – not from a remote cabled door controller. Typically, such installations save end users about 25 per cent of the total cost of a hard wired access control system.
Importantly, major access technology manufacturers like HID and Indala are right behind modular wireless locking solutions and use of highly secure spread spectrum communications enhances the reliability and security of wireless access control solutions.
Making wireless more flexible still, most the major manufacturers have mature integrations with access control manufacturers like Inner Range, Gallagher, Tecom and more. This means not only can existing wired solutions be expanded with wireless, hybrid systems can be installed that take advantage of wired and wireless strengths to create more robust solutions
Important for installers is being sure to go for quality lock/reader solutions able to integrate with their control panels of choice and installing them properly and within the tolerances recommended by manufacturers. As alarm installers know, wireless solutions are sensitive to EMI and RFI, as well as disliking Farraday Shield effects caused by steel building materials.
Annoyingly, the things most likely to affect your wireless access solution are invisible to the human eye and that means you need to plan your system carefully. You need to talk to the facilities manager before an installation to get a feel for the nature of the building’s fabric. And you need to carefully test for ambient EMI and RFI around the site, bearing in mind that stray period EMI and RFI signals may cause system problems.
Attenuation is a key element of any wireless solution so you’ll have to take care not to stretch the signal so far it lacks the power to carry data signals under the worst expected environment conditions you think the site may present. Your signal budget will need to offer about 30dBms for every 60m of RF comms path <I>after<I> attenuation has been factored into the equation. If you’re in any doubt, go for more rather than less signal.
Another issue you’ll face will be security of the comms path. Some wireless solutions are proprietary encrypted, others might live on wireless LANs, which can readily be converted to VPNs, still others move data around on carried tags, making door to controller signals impervious to interception.
A careful reading of the manufacturer’s specifications is a must before you start mapping out an installation. It’s also worth chatting with your access control manufacturer to mine their experience on integrating wired and wireless system components.
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