What's your first concern about installing security cameras for long distance monitoring such as a CCTV metropolitan surveillance system?
The first question that comes to your mind is "How to transmit the videos to a CCTV surveillance center"? That's when you think about wireless IP camera.
But the design of a wireless CCTV metropolitan project is not that simple and you can't just purchase some small wireless IP cameras such as the ones used for cloud recording, and install them around the city.
You need to learn about wireless transmission technology, so you can apply this knowledge to your project and have better chances to be successful.
So, in this article let's dive in into some theory about wireless devices and some other cool stuff. so in no time you will have a better understanding of the necessary concepts and best practices of a CCTV wireless design.
The wireless IP camera technology
I have really good news for you my friend. You just found the article that will explain everything you need to know about Wireless IP cameras and all the technology they use in such easy way to understand that you will be surprised how much you can learn from a single article. So keep reading...
In the image above you can see a happy woman using a laptop on a wireless network. She is happy because it's easy to access the Internet and also because she now can learn all this technical stuff on the Learn CCTV.com 🙂
OK, you are also here to learn more, so let's get started with my question to you: "what wireless frequency her laptop is probably using? "
Perhaps you are wondering what this thing with a woman and her laptop has something to do with a article about CCTV metropolitan project...
C'mom, you got answer this simple question, otherwise how can you understand all the technical details about Wireless IP cameras?
I'll tell you what, you just need to understand from the beginning what are the wireless devices frequencies, transmission speed, standards and a lot of other details necessary to become a really qualified professional
The wireless network frequency standards
The wireless network devices for commercial use such as the wireless routers you have at your home are designed according to technical standards with specific frequencies such as 2.4Ghz and 5Ghz.
Whenever you read about these standards, you find certain acronyms such as IEEE 802.11, which are actually used as a reference to keep everything documented by the IEEE ( Institute of Electrical and Electronics Engineers) which is an engineering group responsible for the creation of these universal well-known technical standards.
I will not go into details about the IEEE in this article, but keep in mind that the standards carry the group acronym followed by numbers and letters. The IEEE 802.11b for example is easily found in your wireless router label.
When you buy a wireless router, (also known as Access Point), you can see it has a label that shows the wireless standard it complies to as IEEE 802.11b, 802.11g or 802.11n.
They are the indication of the frequency and speed that the device uses for wireless transmission.
You can find the same information on your Wireless IP camera label.
Frequency and transmission speed
The first popular wireless standard was the IEEE 802.11b which has a 2.4GHz frequency and a transmission speed of up to 11Mbps.
I remember back on 2004 when our technical team used to discuss the issues related to this standard when designing the metropolitan surveillance system, there was no professional wireless IP camera at that time.
The first wireless network cards for computers and laptops were created in accordance with this standard to work with the frequency of 2.4Ghz.
Later another standard called IEEE 802.11g kept the same 2.4 Ghz frequency but increased the transmission speed from 11 Mbps to 54Mbps and the new computer and laptops started using such standard.
Back there was not easy yet to find a wireless IP camera, but that was not a problem to design the surveillance system, you are going to see why later.
Finally another standard called IEEE 802.11n came out and kept the same 2.4 Ghz frequency but increased the speed from 54Mbps to 300Mbps and now the new computers and laptops could also use such standard.
The important thing to understand here is that the standards have been keeping the 2.4GHz frequency and increasing the transmission speed *
* ( In addition to 2.4GHz, the IEEE 802.11n can also work with 5GHz)
See the summary of the IEEE 802.11 standard transmission speed
11 Mbps
54Mbps
300Mpbs
In most cases you will find laptops that are working with the 2.4GHz frequency and this answers the question I asked in the begging of this article about the woman using her laptop, remember ? Are you still there ? 🙂
I assume you are still reading and willing to learn more, so let's continue...
How about the CCTV wireless network?
What about it? Just buy any wireless IP camera and you are done ! Wait, wait... I'm just kidding, you can't do that before understand the concept...
In fact I'm glad you asked this question, after all you are here to learn more about the wireless technology to use it in your CCTV projects, aren't you?
Or maybe you want to install your own wireless camera....
Anyway, for your home CCTV surveillance project you can use the all-in-one wireless IP camera, but for that huge wireless metropolitan CCTV project with hundreds of IP cameras, it's better not even think about it.
So which of these three standards (802.11b, 802.11g, 802.11n) should I use in a metropolitan CCTV project ? Guess what... "None of them"
Say whaaat? Now you must be thinking that I'm crazy and that I should use the IEEE802.11n standard because it's faster probably a wireless IP camera can be found out there in any electronic store. So what's the catch ?
In fact, for a serious CCTV metropolitan system, it's not common to use the all-in-one style wireless IP camera. It's better to use professional IP cameras with wireless IP radios manufactured especially for use in CCTV projects.
For small projects with few cameras, you can use cheaper wireless radios, but for the huge ones, please just go with the best brand you can find.
Use the 802.11a standard
The 802.11a standard uses the 5GHz frequency and that makes a huge difference for the projects because there's less radio interference and more channels to work with. That's a better choice for the IP CCTV project.
Long time ago the wireless devices using the 802.11a (5GHz) standard were too way expensive, but that scenario has changed. Due to the technology evolution and more manufacturer competition the prices dropped a lot
So, you can buy professional wireless radios from different manufactures such as Proxim, Radwin, Cambium Networks, Fluid Mesh designed especially for IP CCTV application, so you can assure the best quality for your project.
Avoid to use 2.4GHz wireless radio
So it is simple, use wireless radio with the 5GHz frequency, and avoid using the 2.4GHz, unless your project is really simple and your are on a budget.
See the picture below that shows a professional wireless radio
Besides the frequency, there are still many others factors that will impact on the video transmission over wireless networks, all those details are taken into consideration by the professional wireless radio manufacturers.
Wireless radio license and homologation
Hey, did you know that there are many wireless IP CCTV projects that are illegal ? They don't have a license for operation just because people don't know they need one or sometimes the wireless radio are not homologated.
Let's start talking about the professional wireless radios for CCTV, so you can clearly understand how and why to use them. To make things easier to grasp, I'll use an real example of a metropolitan CCTV project that was implemented many years ago. Pay close attention to the history...
CCTV metropolitan case study
OK, so let's come back to the year 2004 when my technical team was facing a challenge. A small city's mayor wanted security cameras installed to monitor and record all main city entrances and buildings.
Everything should be monitored by the local police task force in a surveillance room, specially designed for that project.
Around 60 analog box cameras, and 5 PTZ (Pan Tilt Zoom) cameras. should be installed in the city. Each camera should transmit and store videos at 4CIF resolution at 30 FPs with 30 days recording .
If you don't understand some of the CCTV camera terms used here, just read the article: How security cameras work.
How to broadcast videos from CCTV cameras?
The first challenge was how to transmit videos from the security cameras to the CCTV surveillance center located few kilometers away, the first idea that came to our minds was to use fiber optics .
But use fiber optics would cost too much due to the need of running cables throughout the city using public poles. It's was really too complicated and the logistics and specialized jobs involved was huge.
The solution: use wireless radios
The decision to use wireless radios for the CCTV project was interesting but at that time (2004) there were no modern wireless radios designed for CCTV, so our team had to use the technology that was available.
And guess what... The technology available was the traditional wireless network routers used in homes offices. Those wireless routers were not the best solution to work for a metropolitan CCTV project due to the 2.4 GHz frequency and the 11 Mbps (nominal) speed limitation.
And of course, the wireless radios were not sturdy enough to work in an outdoor environment neither ready to work with intense network traffic.
The bad experience with traditional wireless radio
As I said earlier one of the problems was the use of the 2.4GHz frequency which is subject to a lot of interference from other devices, there were also performance problems in addition to the physical issues like temperature, humidity and even insects entering the box installed on the pole.
Wireless router
At first tests were done with this type of radio, connecting external antennas and installing the radios in boxes in the poles.
In the practical installation we face a lot of problems during the tests and adaptation for outdoor use.
I'll talk about the problems with 2.4 GHz frequency later, but basically, there are only three channels that can be used to avoid external interference.
This wireless router processing is another important factor, since traditional radios for internal applications are not designed for heavy traffic over long continuous period of time, Let's say 24 x 7 x 365.
Box on a pole
Over time the high temperature inside the box has become a problem and the use of fans in the opening of the box has brought other problems like moisture and insects ingress.
Over time, more suitable new boxes were emerging, but it was still a laborious solution to use for CCTV installation.
A better solution to our problem was needed,
Best wireless radios for CCTV
So the installation of boxes on poles was a tremendous headache. And at that time a solution such as all-in-one wireless IP camera with built-in wireless radio and antenna was not available at the market, and even of it was, this kind of device is not suitable for our metropolitan CCTV project.
In order to improve the system we started using sturdy wireless radios that were manufactured for outdoor application, although they were designed for data transmission and not for CCTV, they were at least more adequate for the CCTV metropolitan project we were working with.
Over time, new technologies were emerging and prices began to become more attractive, allowing us to use wireless radios that were specially manufactured for CCTV installation, and then the transmission of high quality videos from IP camera was became cheaper and easier .
Wireless radio for CCTV projects
Now without those huge and ugly boxes installed on the poles, the CCTV projects became more interesting. But is still necessary to have specialized knowledge to design a good wireless CCTV IP project for cities .
Best wireless radios for CCTV
Let's talk about the bandwidth required to broadcast the IP camera video over the wireless network. Just keep reading...
After installing the IP cameras to transmit video over a wireless network, do you measure the speed available for the video broadcast or you just read the information on the wireless radio box ?
The information that is written on the product's box is not the real one the will get in the field, so be really careful with this type of information.
Let's talk about that now...