Wireless Security Camera Overview
February 24th, 2021
First Generation Wireless Security Cameras
The early “analog” cameras send out the video signal to a receiver, which can be then connected to either a video monitor or a recording device, such as a videotape recorder, or digital video recording system (DVR). Note that most of them operate over the 2.4 GHz band, the same band that a lot of other household wireless appliances, such as cordless phones and video game controllers, operate on. Additionally, microwave ovens operate at 2.45 GHz, and radio-controlled toys also use the 2.4 GHz band. You can see there are many possible causes of interference when using these kinds of cameras. Not only can the camera interfere with the other devices, but it also works both ways – the other equipment may interfere with the camera’s signal, causing low-quality video.
Analog Wireless Security Cameras Have These Advantages:
* They Cost Less:
* They can be used with more than one receiver;
* You can use as many as 12 cameras with a single receiver;
* Setup and installation are easy. You can have a wireless video security system operational very quickly, and at low cost.
Analog Camera Disadvantages:
* Shares frequency band with other common electronic devices;
* The signal can be intercepted and viewed by anyone with a receiver;
* Easily interfered with.
For installations where there are a lot of physical obstructions, look into installing a system using 900MHz transmission. For small systems, where only 1 or 2 cameras are required, the 900 MHz versions may be an excellent solution. For more channels, up to 12, look at 2.4 GHz wireless cameras. Since there are many devices now that use this frequency range, you may have interference. There is less interference when using wireless cameras based on the 5.8 GHz spectrum. There are 8 channels available (so you can have up to 8 cameras). For best results only use 5.8 GHz wireless when there are few physical obstacles. Walls and other objects cause signal degradation.
Transmitter Power Output Affects Signal Strength and Distance
When selecting an analog wireless security camera system, make sure you find out the transmission power and determine whether this will be enough to overcome any obstacles in your system.
Most claims of distance are for line-of-sight transmission, where there are no obstacles between the camera’s antenna and the receiver’s antenna. This rarely happens. Factors such as distance, weather, trees, buildings, walls all have an effect. Due to the short wavelength of 5.8 GHz signals, they have the most difficult of the 3 frequencies available to pass through obstacles.
Digital Wireless Security cameras
Digital security cameras are more sophisticated than analog wireless cameras. The digital video signal may be compressed or uncompressed before it is sent to the receiver, where it will be re-converted to the baseband for viewing unless it is an IP camera (discussed below). The transmission frequency is usually 2.4 GHz, however, because it is digital, there are fewer interference problems. Transmission power is usually 16dBm, which is a bit under the typical wireless router power.
Advantages Of A Digital Wireless Security Camera:
* The range of transmission of the signal is as much as 450 feet with line of sight between camera and receiving station;
* Video and audio quality higher than analog;
* Allows for audio communication to the remote site;
* Digital video can be encrypted to maintain the security of the images.
Connecting a Wireless Security Camera To a Local Area Network
Wireless security cameras are now available that can connect through a local area network over IEEE 802.11b/g WiFi systems. The camera has it’s own IP address on your network in Omaha, NE and can be viewed using a browser.