- Types of systems and their elements
- Analog systems
- Mixed systems
- Digital systems
- IP cameras
- Access point
- Computer and router
- System installation
In our time, the development of information technology has gone so far that video surveillance has become an integral part of the precautions taken to protect their own property. More recently, the installation of video surveillance systems was practiced only at large enterprises, in the central offices of companies, and was also used as a tool by law enforcement agencies, etc..
Now the computer equipment market is wide and diverse, and prices for the entire range have decreased so much that practically every citizen with an average income level can organize a small video surveillance system. Video surveillance is used both in apartments and in private houses, it helps guests not only protect property from theft, but also control their territory for all kinds of situations that may not be criminal..
Types of systems and their elements
A video surveillance system is not only a video camera and a TV, as many are accustomed to believe until now, in fact, it is a network that consists of certain elements communicated with each other by transmitting signals through a cable or radio waves.
Several types of systems are distinguished depending on the devices used in the video surveillance network and the classes of equipment..
Such systems include analog video cameras, multipliers, video recorders, storage and information output devices. An analog signal from CCTV cameras is fed to a video recorder, which allows you to configure system control modes, record information, display information on monitors, etc. The multiplier is used so that in one line it is possible to receive and convert signals not from one, but from several cameras simultaneously, which makes it possible to simplify the network structure. Information in analog systems is recorded on magnetic media. Due to the large number of devices and communications, such an implementation of a video surveillance system is impractical and cumbersome, therefore it cannot be compared with mixed and digital systems..
The structure of mixed video surveillance systems includes analog video cameras and recorders, but the use of video capture cards allows converting an analog signal into a digital one. Such cards are mounted in PCI slots of stationary computers, which makes the system more flexible in terms of management. Information recording can be performed both on analog media and digital.
Such systems are considered to be the most progressive, convenient, compact and cheap. The transmission of information can be organized in two ways – via cables, as well as via a wi-fi connection. The structure of this system consists of a number of devices, half of which are available in almost any house or apartment where the Internet connection is used. To organize a digital video surveillance system, we need ip-cameras, a switch, a router and, in the case of a wireless wi-fi option, an access point.
This is one of the best devices to date that allows you to take video. In terms of dimensions, such a camera does not exceed the dimensions of a pack of cigarettes, which is an important point in the organization of hidden video filming. This device is powered from 12–24 V, it comes with a power supply unit, the size of which does not exceed the size of a standard charger for a mobile phone. The camera is equipped with a web interface, thanks to this option, there is a very convenient opportunity to configure and control it. Despite their size, IP cameras have excellent performance. The frame rate allows you to update the picture up to 30 times per second, the average resolution is 640×480, which is quite enough for normal observation. The camera allows you to shoot at a minimum illumination of 0.5 lux (lux is a unit for measuring illumination, an indicator of 0.5 is almost absolute darkness), this effect is achieved by using infrared LED illumination. The video shooting range can reach 50 meters, and the viewing angle is about 180 degrees.
The camera supports all standard network protocols, including POP3, which allows you to receive information directly to e-mail. The camera also supports 3G communication, so you can receive images in the form of MMS on your phone, which also supports this communication standard.
TP-LINK has proven itself best in the production of such cameras, the prices for its products are about $ 120 per unit.
A switch is a physical device that is designed to combine several computers into a local network. To combine the switch and computers, twisted pair and standard RJ-45 connectors are used. Thus, the switch can be used to connect multiple digital surveillance cameras to the network. Switches are often confused with hubs. A hub is a device that also unites several computers into a network, but it also redirects the signal received from one device to another by comparing network addresses, while the switch sends the received signal to all ports without being interested in the address of the network card. In our system, according to the standard, only one computer with one network card is used, so there is no need for a hub, and its cost is slightly higher. It is recommended to use switches from TP-LINK or ASUS, a small 4-port switch will cost you no more than $ 15.
This device is used when transmitting information via a radio signal. An access point can play two roles:
- Information receiver (when twisted pair is not used, and information from the camera to the switch is transmitted through the access point without wires).
- A repeater, in other words, is a bridge (if the distance between the receiver and the transmitter of the wi-fi signal is too great, you can place the access point in the center, it will automatically transfer the signal from the camera to the switch, for this you do not even need to perform any settings).
Many people want to make the video surveillance system hidden from prying eyes, just in this case the access point will come in handy, it will rid the entire structure of wired connections.
The best access points are presented by TP-LINK, their cost is within $ 40.
Computer and router
To organize the system, you do not need to install special software on your computer; all settings are made directly on the camera itself via the web interface. If you do not have a router, but you have a dedicated ip-address from your provider, you will not need anything else except a computer. The use of a router is only necessary if this is a condition when connecting to the Internet with your provider.
With the help of a digital video surveillance system, you can inspect your property from anywhere in the world, having only access to the Internet at hand, as well as a smartphone or laptop or computer. Using motion sensors, you can configure the alarm and video recording system in such a way that cameras start shooting video only in case of intruders entering your territory. By concluding an agreement with a security organization, you can redirect the alarm signal to the central dispatcher’s console, so that unsuspecting intruders can be neutralized and detained in a matter of minutes.
The first step is to determine the number of points that need to be inspected with the help of cameras; for this, a detailed plan of the network topology and a plan for placing cameras around the object are drawn up. The security of the territory and property depends on their number, as well as the price that you will have to pay for the construction of the system.
You don’t need to be a professional for installation, a conventional drill or hammer drill is the most complex tool that you will use. Cameras are attached to the surface using special brackets, it doesn’t matter if it is horizontal or vertical. For laying the cable, an electric box or ordinary clamps are used, which are attached to the walls in 1 meter increments. When laying a twisted pair, it is necessary to strictly adhere to one rule – do not lay it at a right angle, it is better to make a slight rounding, the twisted pair is very fragile and can be easily damaged, and when the temperature changes (due to the change of seasons) in places where there will be a right angle, the wire may crack and compromise the integrity of the system.
In almost 90% of cases, at the location of the camera, it is not possible to connect the power supply to the 220V network. What to do in this case? Everything is elementary, a green and an orange pair of wires is used to transmit a logical signal, this is due to the fact that they have better induction due to the density of the turns. The brown and blue pairs can be used to transmit a voltage of 220 V. This technique works only when connecting devices with a low current consumption (like our cameras), since the wire cross section is very small, more powerful devices simply burn the wire.
Calculate in advance the amount of wire to use when installing your system. This will be needed so that, when purchasing, a specialist can cut the wires into the required lengths and crimp them with RJ-45 connectors. This procedure costs a penny, but you will not be able to handle the crimping machine the first time, but over time you need to purchase such pliers so that you can fully service your monitoring system yourself. You can buy crimping pliers at any computer store for $ 20- $ 30, and you can learn how to use them by following the instructions from the Internet.
In the case of a wireless system, you first need to survey your territory for the radio signal throughput. The standard line (camera / access point) is within 150 meters, but this assumes an open space. If obstacles in the form of walls or other objects appear on the way, then the signal range decreases, this must be taken into account. Otherwise, the installation of the system is no different, only the method of signal transmission from cameras to a computer is different.
When installing a video surveillance system, take care of the safety of the elements of the system itself. Cameras must be equipped with visors that will protect them from all kinds of precipitation. It is better to pack cable connections in a corrugated or electric box, they are good protection for communications. Mount CCTV cameras as high as possible, this will provide not only a good view of the territory, but also will not allow intruders to disrupt them.