Transmitting video signals has been done in many ways throughout the years. The absolute latest state-of-the-art video transmission is now done with a technology known as Coded Orthogonal Frequency Division Mulitiplexing, or "COFDM."
Whereas wireless network transmission requires line-of-sight or at least near line-of-sight, COFDM thrives on bouncing coded signals around within a wide range of frequencies with high efficiency. The technology makes it much less susceptible to channel interference, poor transmission conditions, bad or no line-of-sight, etc.
The transmission technique uses multiple carriers to provide high quality real time video images in environments and situations where conventional video links would fail through multipath interference. Unilux offers three systems based on the COFDM technology, each one for specific needs:
ARDPET System The ARDPET system is an entry level COFDM link with many features of its military relatives. It has been designed with professional security users such as law enforcement in mind. It consists of a down converter unit and IF receiver to allow the widest range of practical installations. And power to the down converter is fed via the feeder coax to minimize installation costs.
An optional splitter can be used to run two receivers simultaneously from a single converter allowing two channels to be received at once. The standard unit operates on a single RF channel, and multi-channel versions are available with channel selection via a handheld contoller or PC. It has 50mW to 1 Watt power, no audio, conforms to IP67 environmental standards and wieghs less than 4 pounds.
GUARDIAN System The Guardian System is a ruggedized lightweight and very compact system for transmission and reception of video, audio and data signals. Using MPEG-2 compression and 1704 carrier full broadcast quality COFDM, the systems provides high quality video and audio transmission. It is only 1 cm wide and can be worn on the body or easily concealed in almost any situation. It can utilize a variety of antennas and frequencies for flexibility. A single edge connector is used for power, video and audio. A typical range would be over 300 feet in an urban non-line-of-sight area, including inside buildings.
The unit may be purchased with other options for ease of operation. These include discrete holster, hand-held receiver (the Handy-View) as well as full briefcase-size receiver system with LCD, hard drive and speakers. It has the option for up to 10 Watts of RF power, and weighs less than 2 pounds.
SNOOPY System The Snoopy System is a very ruggedized weather resistant system designed for use in more rural areas where traditional COFDM equipment would not work as well. The system uses a limited number of carriers in minimal bandwidth, and the video and audio signals are compressed prior to modulation. Also suitable for non-line-of-sight operations, it has been designed for discrete military and police use in rural and semi-rural areas. It works well in areas of high forestation, wet foliage, over hills, etc.
Normally operating in a 370 to 430 MHz, 1-watt narrow band range, other frequencies are available on request. The transmitter weighs just over 2 pounds and uses military-style connectors. A typical non-LOS range would be between 2 and 3 miles.
