There is a small hype surrounding surveillance cameras with WLAN function which are available on the market for private security technology because many first of all associate WLAN with convenience. Is video surveillance going to be even easier to implement, now? Is video surveillance via WLAN the new ultimate solution? The fact is that video surveillance for private properties is becoming more and more cost-effective and is no longer a privilege for large mansions. However, our expert for video surveillance, Mr. Harald Buchholz, takes a critical view on the euphoria surrounding the connection of video surveillance with WLAN. In his opinion, WLAN makes a lot of things easier but this rarely applies to video surveillance.
There are some scenarios where cables are not an option. A few scenarios are listed below:
- It is a listed building
- The walls are of a very high quality, either made of a high-quality material or feature a high-quality coating or paint
- It is a subsequent installation in which the installers cannot or are not allowed to open any walls, e.g. with a cold storage house or clean room
- A single video surveillance camera is sufficient and is positioned near a router
- Cables should not be visible and covering them is out of the question, too
In case, the above conditions do not apply, surveillance systems with IP technology or standard coaxial cables are usually the better choice, for the following reasons:
1. Multiple walls and few WLAN sources together result in a problem
Walls attenuate the signal particularly well due to the high frequency of WLAN. If other factors such as tiles on the walls are added, it becomes more and more difficult. Tiles are varnished which contains metal salts, often titanium dioxide. This is a similar strong shielding as aluminium foil. Therefore, it requires a very comprehensive coverage with WLAN. This is quite expensive because you have to use several repeaters which in turn need power and a strong signal. Various paints and wall coatings also shield very well.
2. If you are using multiple cameras, you must apply a state-of-the-art WLAN infrastructure
The number of registered cameras in the WLAN network is almost unlimited. However, the images from video surveillance cameras are quite large nowadays and thus cause a large amount of data. Therefore, it requires a certain bandwidth in order to transmit these images at an acceptable speed. Assuming that we are applying 3, 4 or even more cameras, we require a wide bandwidth and repeaters due to the walls. All in all, the effort clearly exceeds the more cost-effective wired solution.
We must never forget that video surveillance is not the only element in the WLAN network. Streaming and other end devices all use up bandwidth.
3. Video surveillance cameras require cables, even if they are operated via WLAN
At first glance, this might, of course, be an obvious statement. However, I have often encountered this mistake in day-to-day work. Even though video surveillance via WLAN is wireless, this only applies to the data. If I want to have video surveillance in my garden, I still need electricity. This means that I still have to lay cables and install sockets, which is a great effort, especially for outdoor installations. Therefore, it may not be as appropriate to use WLAN cameras.
Most installers have already got experience with this technology: connect and crimp cables and plugs, otherwise plug-and-play
- Same quality as digital technology
- Upgrading existing outdated systems is very simple
- New recorders are almost always compatible with old cameras using the same technology
- Satellite/antenna leads can be used instead of video leads; you only need to replace the plug
- Cable lengths of up to 300 metres can be implemented
- The existing network infrastructure can be used immediately.
- No point-to-point connection necessary. There is no need for a single line from each camera to the recorder. Therefore, users can plug the recorder into an existing IP network anywhere.
- The average data rate is 7-10 mbit. If several cameras are used, a separate, self-contained network is recommended.
- Recorders with PoE capability make a power source unnecessary. Using Power over Ethernet, an IP camera could also work with a single cable that carries both data and power.
- The cables are thinner than coaxial solutions.
- Cable lengths of up to 100 meters can be implemented.
The costs for cabling are often significantly lower than those for a state-of-the-art WLAN infrastructure. WLAN only proves to be an ideal addition for video surveillance cameras in special projects. Most of the time a cable-based solution with modern and easy-to-use cameras and recorders is more appropriate for private video surveillance.