Member Discussion

Wireless (Wifi), Megapixel Cameras

Has there been any articles written about wireless mebapixel cameras? Pros and Cons? How much do they overload a LAN? I have a client that would prefer wireless cameras in the 720P and 1080p range. I have not found much educational information about wireless cameras.

Hello David:

The most common approach is connecting megapixel camera(s) to a separate wifi radio, like you'd find with Ubiquiti or a similar network gear vendor. The radio itself needs to take into consideration how much bandwidth the MP (megapixel) camera will need to stream.

For example, we have a current discussion: How Many Cameras Can I Run On A Ubiquity Nanostation M5?

However, just how effective a wifi solution will be depends on a variety of factors, namely: what is the total expected bitrate of the cameras, how far is the distance, and do I have clear line-of-sight between endpoints?

Finding a MP camera with integrated (built-in) wifi is uncommon. Integrated wifi radios into cameras are typically poor performers compared to separate radios that can be designed (total needed throughput/antenna selection) for the specific application.

So: Can MP cameras be wifi networked? Absolutely yes, given the hardware behind the camera is properly sized.

If you have other questions, please ask.

Thank you, Brian, for your suggestion about standalone WiFi transmitters. I had not thought of an external device. Originally, I was looking for cameras with built-in WiFi capability. I noticed that Sony has several wireless cameras, but I like your idea of a standalone device. Then, I could choose a camera that meets the clients needs, rather than having to select one just because it was wireless.

I personally recommend wireless as only a last resort or in cases of extreme cost to get from point A to B for a variety of reasons that would be a much longer post. For example, dropped packets are constantly a problem in a shared medium, which low output unlicensed frequencies definitely are. Your mileage may vary and it depends heavily on the quality of equipment used, gain structure of equipment, and type/frequency of Wifi equipment used.

Also, keep in mind that it's not just line of sight that is needed over longer distances. There are fresnel zones to contend with.

20% blockage of the fresnel zone is minimal interruption but at 40% there is significant interruption. At 60% there is effectively no signal. Here is a good calculator for Fresnel zone size. Since it is in miles/kilometers the distances must be entered as decimals.

For example, a 600' distance at 2.4 GHZ has a 7' radius fresnel zone around the line of sight. At the mid point, the fresnel zone is effectively a 14' circle.

If your distance is much shorter, e.g. 300' you likely will run into much more interference before worrying about fresnel zones -- firewalls, reflective surfaces, etc. If you are going much further than that count on an even larger fesnel zone.

Austin, I had heard of the term "Fresnel Zone" before in terms of a WiFi signal, so I went over to Wikipedia to learn more. What I learned is that there is more information I need to know before specifying wireless cameras. Going from wired to wireless presents another learning curve.

I think that before using wireless gear, I should first be certain that it absolutely is not possible to run cables.

For complex wireless video surveillance projects you should definitely partner with an organization that is specialized in wireless networking. But I wouldn't say use wireless only as a last resort. For a simple point-to-point short run deployment, for example tranmitting to a camera in a parking lot to avoid trenching, I don't think you need to be too worried as long as you have some networking expertise. Just insure you have line-of-sight and are aware of things that can potentially cause interference. Suggest using 5 GHz which is normally less crowded than 2.4 GHz. We are not wireless experts but are involved in this type of thing all the time and rarely have issues that aren't easily resolved.

There is a stark difference between using wireless cameras and using a wireless backhaul. If your client intends on simply using an existing wireless network to connect every camera for the purpose of eliminating wire, I think you will find that a poor choice.

on the other hand, if the goal is to use a wireless backhaul to connect cameras from another building or something where a wire isn't practical, then I would say that is a much easier task, given the area lends itself well to a wireless solution.

Hello David

I'm very glad you brought the wireless aspect into this discussion. I had been having trouble too with wireless cameras such as an Axis M1033W. I am incorporating them into a wireless mesh network using backhaul. I can only use the 2.4 frequency which is overcrowded. Thanks to Austin, I have never heard of the "Fresnel Zone" and will be doing more research. Luckily this was experimental and not needed by a client.

If the camera has WiFi built in, that's not backhaul. That is a wireless device using a wireless network.

In our projects, we used wired IP cams into localized PoE switches and used NanoStation Loco M5s for the consolidated backhaul links to the central office.

I very much appreciate all the responses I have received concerning wireless security video. I am puzzled, though. Several of the responders have used the term "backhaul". I can guess what that might mean, but in reality it's a new term for me. Could someone please provide a definition, and relate some additional information of how it is used.




If you are just connecting a single camera via wireless to a building and then directly on to a wired network, that's local, not backhaul.

If you are aggregating many camera wireless feeds over multiple links / hops, that is backhaul.


I see you are having issues with the two different aspects of wireless, so I will try my best to explain in simple terms why they need distinction.

1) Normal WiFi: This would be a scenario where you have omni-directional access points and cameras. They aren't purpose built for each other. If you have just one AP per camera, it may work fine. But add in more than a few cameras per AP and you will find the AP struggling to keep up with the data load. You also will have a much higher likelihood of interference due to multiple wireless paths and omni-directional antennas that are susceptible to interference.

2) Wireless Backhaul: This would usually consist of two point-to-point (PtP) wireless radios aimed directly at each other with very directional antennas. The directional antennas help alleviate sources of interference as well as adding as little as possible to the area themselves. You would still have the cameras wired to a local switch along with the PtP radio. The switch would combine all the cameras transmissions into a single uplink to the main switch and recording system via the wireless link. Since these PtP links only communicate with each other directly, they are able to handle more throughput and are less likely to have issues.

Jon, You've made it clear enough for me to understand the concept. I can see the benefits of using a backhaul system, rather than just trying to jam the video onto an existing WiFi LAN. One part, though, still seems fuzzy. You said "you would still have the cameras wired to a local switch along with the PtP radio".

I can understand the PtP receiver being connected to a switch, but the cameras are on the transmitter end, and I assumed they would be plugged directly into the PtP tramsmitter. Are there some PtP systems that are multi channel, that could transmit two, or more, camera signals.




I would encourage you to read up on a very similar discussion where that very topic is being discussed (multiple cameras over a single link)

How Many Cameras Can I Run On A Ubiquity Nanostation M5?