Integrator - "Hi. This is Bob with Tesla Security. I want to quote your ABC100 system for a project I am working on and I need to know how far the readers can be from the controllers."
Manufacturer - "Well that depends, Bob."
Integrator - "Of course it does. I understand. Assuming I use the cable that you recommend and run it correctly, what is the maximum distance?"
Manufacturer - "Well it could range from 30 feet to 300 feet. It depends on a lot of variable conditions at the site."
Integrator - "Exactly WHAT kind of conditions? The job is in Kimmirut in Nunavut and I am quoting the job from a set of floor plans."
Manufacturer - “Things such as the ambient RF noise and the thickness and construction of the interposing walls and floors must be considered.”
Integrator - "How the heck am I supposed to know ANY of those things without going to the site and spending DAYS doing a site survey? And what's more, the facility hasn’t even been built yet! I need you to give me the exact number of feet that the reader can be from the controller so I can submit my quote by noon today!"
Manufacturer - "I would love to do that Bob but I just can't. It depends. Is there anything else I can help you with today?"
Integrator - "Goodbye!"
This obviously doesn’t happen with wired products. The manufacturer can tell the integrator EXACTLY how many cable feet are permitted between the readers and the controllers. The integrator can then lay out the system, determine the specific equipment required and, if necessary, prepare a wiring riser.
But if that integrator is calling about a system which uses wireless locks connected to gateways and he needs to know how far the locks can be from the gateways, he will get the only answer that the manufacturer can possibly give - it depends.
For the record, I am a huge fan of wireless, in spite of its unique challenges. With wired devices, you can break a lot of installation rules and they may still operate, albeit intermittently. Wireless devices, however, are much less forgiving. A wireless device may be working perfectly when it is first installed but if something happens to change the ambient RF noise, it may no longer work reliably. By all means, use wireless in the many circumstances where it is cost-effective, but do so with your eyes wide open.
The challenge for wireless product manufacturers is formidable. When quoting wireless ranges, they can play it safe and quote worst-case figures. This reduces their liability but makes their product appear non-competitive unless everyone is doing the same. Some will quote ranges "up to" or "line of sight" but will have a disclaimer stating that…. depends”. Right now, there are no industry standards on how is reported but one is urgently required. Wireless already has a black eye for not living up to the marketing claims being made. As more companies release wireless products, the problem just gets worse.
It doesn’t help that there are a lot of misconceptions about wireless. Take “line of sight” for example. One would think that if you can clearly see the receiving device from the transmitting device, you can expect to achieve the “line of sight” range claimed by the manufacturer. That would be an incorrect assumption. of sight requires not only an unobstructed path, it requires that both devices be mounted at a specific height. So if you were testing a device with a stated “line of sight” of 3 miles and did so on the Bonneville Salt Flats in Utah, you would not achieve the 3-mile range unless the devices were mounted at a specified height, even though there are no obstructions whatsoever between them. This is not an issue with wireless locks which have ranges measured in feet and not miles, but it does make the point that there is more to wireless than meets the eye.
Until there is a universal method to state wireless lock range, the best that manufacturers can do is;
As for integrators, don’t be fooled into thinking you can treat wireless products just like wired ones. You need to understand the limitations of wireless products as well as the benefits. Wherever possible, avoid deploying devices on the edge of a signal envelope as even a small change in ambient RF noise may adversely impact their performance. It is simply a fact of life that there will be more callbacks for wireless devices than for wired ones. If you don’t make provision for these in your pricing, the profits you made on the sale and installation may be seriously eroded by increased support costs.
Chief Simplification Officer
Cansec Systems Ltd.