When designing a surveillance system, one of the most commonly heard requests is to make the system wireless. The rationale for this makes intuitive sense: if there aren’t any cables to be run, the installation would almost certainly be much less expensive. Unfortunately, though, when working with cameras, things just aren’t that simple, and the use of wireless technology in this case almost always results in a system that works less reliably and is therefore less secure. To understand why, though, we must first understand the way wireless devices work.
Any wireless connection must consist of at least two objects: a transmitter and a receiver. The transmitter sends out a signal in all directions, creating a bubble in which it can communicate with the receiver. As long as the receiver is located somewhere within that bubble, then it can find the transmitter’s signal and decode it into something useful. Virtually all wireless devices work in this way (this “bubble” concept is why it is possible to pick up a radio station anywhere within a certain distance from the tower), meaning that in most urban or suburban environments we’re basically surrounded by wireless signals from radio, television, wireless internet, cell phones, and other sources, and all of those signals overlap and can get in each others’ way. When wireless signals start to trip over each other like that, the result is static and other forms of interference in the signal, which cuts down on its quality.
This is the reason why wireless cameras are seldom a good idea: since most people live with so many wireless devices around, wireless cameras, which use fairly weak transmitters, must compete with a lot of background noise in order to function. What this ultimately means is that the video taken by wireless cameras looks much worse than video taken from wired cameras because of the interference caused by other wireless devices: you see a picture, but it’s almost always distorted in some way. In short, when dealing with wireless cameras, the price of an easier installation is poor video quality that can make identification of people or objects very difficult.
As if that weren’t enough, it actually gets worse. Because wireless cameras create relatively low-powered signals, even in the absence of any wireless interference (a scenario that’s practically impossible to find in most cities) they also tend to have difficulty going through walls and other obstructions, meaning most wireless cameras will need to be within about 150 feet of their receivers. This makes designing a system much more constrained and difficult, and can force designers and installers to leave cameras out, or invest in additional equipment to try to relay the signal around obstructions (negating any savings wireless may have offered). Additionally, as a final performance limitation, to make a camera truly wireless battery packs would need to be used and changed (on average) every seven hours to keep the camera going. When considering this, one starts to wonder exactly how much more convenient wireless cameras actually are; there’s the one time hassle of running cable for a wired camera versus the three-times-daily hassle of replacing batteries on a wireless camera.
Given all of the limitations of wireless cameras, it’s easy to see why very few installations employ them. When designing a surveillance system, especially for residential or commercial spaces where neighbors are close by, it’s almost always best to err on the side of caution and accept the temporary inconvenience of running cable to get a vastly higher level of reliability and functionality from the investment. This is not to say that wireless cameras don’t have a place in today’s systems, though. For example, parents looking for a quick and easy baby monitoring camera could go wireless not only because the camera itself is temporary, but also because in this scenario it may be possible to run local power to the camera instead of using battery packs. Similarly, during sting operations law enforcement entities almost always use wireless cameras to get footage, because a wired setup in that scenario simply isn’t realistic. Still, even accounting for scenarios such as those, the fact is that wireless technology, even as far as it’s come, does not deliver the performance needed when it’s coupled with a professional-grade surveillance system, and as a general rule, it’s always best to avoid using it if at all possible.