There's still some mistrust within the general customer population that wireless is not secure, that it can be 'jammed', you get limited of throughput, and so on. The industry is to a certain extent responsible for this attitude. There are no true standards in the wireless world; one vendor's equipment can perform entirely differently than the other's, even if both are saying "optimized for video" or "mesh capability." The Trust-But-Verify approach is definitely required at all stages of your technology selection process.
Once fiber or cable is in the ground you know it's there, and wired infrastructure has standard performance over a specified distance. (To be fair to wireless, fiber can be cut either accidentally, such as during construction, or maliciously.) With wireless, however, your system is operating in a dynamic, changing environment -- whether seasonal (i.e. foliage, a wireless installer's arch enemy); construction (a new building may block your line of sight); or RF (a new system is put up in the area by someone else). All of these contingencies need to be accounted for to ensure that the system that works great during the acceptance test performs as specified 3, 6 or 12 months down the road.
So What Does Sell?
All this caution aside, let's look at what sells and what you should be looking for in your wireless technology of choice for video surveillance applications.
- First and foremost, verifiable successes in the field. Even then, make sure that that a satisfied customer you are talking to has a similarly sized deployment. Wireless often has challenges scaling; a technology doing a good job with a dozen of cameras may not scale up to 25 or 50 cameras.
- Capacity, capacity, capacity. Everybody wants to put more cameras on the network, or add megapixel, high-definition (HD) or thermal imaging cameras. Keep in mind that a single top-of-the-line megapixel camera may require as much as 35 Mbps of throughput.
- Multi-hop capability, which allows you to go around obstructions, to depend less on wired or wireless backhaul, or to get around the limitations of point-to-multi-point systems. Ask the question of what if you cannot get access to rooftops for your base station units?
What is Hype Rather Than Reality?
- Theoretical radio data rates. Several vendors I know are fond of supplying theoretical data rates in their press and promotional materials; as a rule of thumb, these numbers translate to 30 percent to 50 percent of real-world throughput.
- Professional-grade video surveillance over cellular data service or Wi-Fi access points. Yes, it may work in certain deployments that do not require real-time connectivity or are okay with intermittent, "best effort delivery," but generally you can forget about high-quality, real-time video over these technologies.
- Fixed WiMAX for video surveillance. Performance numbers are hard to come by, although it appears that 20-30 Mbps is typical (often the theoretical data rate is 70 Mbps), divided by the number of subscriber units (WiMAX is a point-to-multi-point technology). Mobile WiMAX as a 4G technology -- such as deployed by Sprint/Clearwire in a few major markets -- typically delivers 3-4 Mbps downstream and 1 Mbps upstream throughput. 1 Mbps may be enough for 1 or 2 covert cameras where quality or 100 percent availability is not an issue, but it is not a fit for a large-scale, professional video surveillance install.
What is bunk?
- Wireless is not secure.
- Wireless cannot deliver the performance needed.
- Anybody can do wireless - just throw the gear up on poles.
With the right combination of technology and integrator's skill, wireless will work beautifully. Wireless can be frustrating, but when it does work, "wow" and "you can achieve this quality over wireless?" is what you are likely to hear. I'm going to leave off on this positive note. And what should you expect from your wireless vendors? Perhaps they should stop "selling" and start delivering.
About the author: Ksenia Coffman is a marketing manager for Firetide and is responsible for Firetide's marketing strategy and technology solution partnerships. Coffman's articles on wireless infrastructure appeared in various publications. An ASIS member, Coffman is a frequent speaker at industry events. She can be reached at email@example.com.