A Digital Video Recorder or DVR Wireless Security System is one of the most popular systems used for security and surveillance applications today. Although there are many variations of a typical DVR Wireless Security System, the general set-up for a security/surveillance application of this type involves the use of wireless Closed Circuit Television or CCTV cameras and a digital hard drive used to record the pictures or video sent to it by the CCTV cameras.
The key components of a DVR Wireless Security System include wireless CCTV cameras with antennas, a high speed digital hard drive, a wireless single or multi receiver, and a digital video recorder. Each of these components serves a specific function to provide a total package DVR wireless security system. Let’s take a closer look at each component.
The wireless camera comes in many varieties. There are dome cameras, box cameras, bullet cameras, PTZ or pan tilt and zoom cameras, and even explosion proof cameras. Wireless security cameras may capture still pictures and/or motion video and may provide the images in black and white or in color. Some cameras also come equipped with a microphone for capturing sound. In addition to these functions, wireless security cameras normally have an on-board transmitter that operates in the 2.4 GHz or 5.8 GHz bands. The broadcast range for these wireless cameras is usually somewhere between 200 and 700 feet depending upon environmental conditions.
The receiver is basically like a radio receiver or in-home wireless telephone receiver base. It receives the wireless signal transmitted from each camera and sends that signal to the DVR. Generally, receivers have more than one “channel”; that is, they can receive signals from more than one camera at a time. A receiver that can handle input from four different security cameras at one time is usually referred to as a four channel receiver.
After the camera’s signal is received, it is normally processed in some way before it reaches the DVR. The processing circuitry is normally found on an electronic “board” that is included with the DVR. This board may have one to several different file compression/decompression or CODECs wired into its circuitry. The purpose of using a CODEC is to minimize the size of the file to be stored on the DVR without sacrificing too much quality.
Digital video is basically nothing more than digital photographs taken at a rapid rate (normally up to 30 frames per second or fps). However, if you consider the digital size of a file for one photograph, you can only imagine the total size for thousands used to create a video. For example, a typical digital photograph may create a file 1.5 megabytes (MB) in size. One hour of video would be 30 photographs per second, times 60 seconds, times 60 minutes or 162,000 MB or 162 Gigabytes (GB) of information! A 250 GB hard drive would be filled in only two hours. However, CODEC boards reduce the file sizes drastically allowing for several hours to days of recording without filling up the hard drive.
Most DVR wireless security systems also include a monitor to view the cameras’ output in real time as well as to view the playback of recorded video. The monitor may be a small wireless unit itself or can be a larger LCD type monitor used with most computer systems.
There are many benefits to using a DVR wireless security system. Technological advances have made the components relatively inexpensive so that these systems can not only be used by businesses but can be used by consumers to provide security surveillance for the home. Wireless systems have the added benefit of placing the cameras in strategic places that are unlikely to be seen by potential criminals and vandals. In addition, DVR wireless security systems do not require signal transmission cables from the camera to the DVR, making installation much simpler and neater as well.
