The existing monitoring transmission which has several ways

The existing monitoring transmission equipment which has several ways, what advantages and

disadvantages?
At present there are video baseband transmission, optical fiber transmission, network

transmission, microwave transmission, twisted pair balanced transmission, broadband transmission

six transmission modes.
But, national standard "civil closed circuit monitoring TV system engineering technical

specifications" (GB50198-94) require the use of only video baseband transmission, optical fiber

transmission,
RF (broadband cable transmission, three forms).
1 video baseband transmission: is the most TV monitoring the traditional transmission, without

any treatment on 0~6MHz video baseband signal, through the coaxial visual control
Non equilibrium) signal simulation of direct transmission. Its advantages are: the short distance

transmission of image signal loss is small, low cost. Disadvantages: short transmission distance,

300 metres
On the high frequency attenuation is larger, can not guarantee the image quality; a video signal

cloth of a cable, transmission control signal to the other cloth cable; the structure of star
Shaped structure, large amount of wiring, maintenance difficulties, poor scalability.
The 2 optical fiber transmission: common analog optical transceiver and digital optical

transmitter and receiver, is the solution of dozens or even hundreds of kilometers of television

monitoring transmission best solution
, through converting video and control signal for optical signal transmission in optical fiber.

Its advantages are: the transmission distance, low attenuation, anti-interference performance is

best,
In long distance transmission. The drawback is: for signal transmission is not enough economic

monitoring within a few kilometers; light and equipment welding and maintenance needs of

professional and technical personnel operation
Maintenance, high technical requirements, not easy upgrading.
3 network transmission: is to solve the distant point, extremely scattered monitoring

transmission mode, the audio and video compression and transmission of control signal. Its

advantages
Point is: the network video server as the monitor signal uploading device, a Internet network,

install the remote monitoring software can monitor and control.
Its disadvantages are: influenced by the network bandwidth and transmission speed, transmission

monitoring image number and FPS limit.
4: microwave transmission is one of the few kilometers or even tens of kilometers is not easy

wiring site monitoring transmission solution. The FM modulator or amplitude modulation
The way of the image, equipped with the high frequency carrier, into high frequency

electromagnetic wave in the air transport. Its advantages are: save wiring and cable maintenance

costs,
Dynamic real-time transmission of broadcast images. The drawback is: due to the use of microwave

transmission, commonly used in the 1GHz frequency band of L band (1.0~2.0GHz), S
Band (2.0~3.0GHz), Ku band (10~12GHz), transmission environment is open space is very susceptible

to external electromagnetic interference; microwave signal is linear transmission,
With no mountain, building block; Ku band is seriously affected by the weather, especially the

rain and snow weather will have severe rain attenuation.
5 UTP transmission (balanced transmission): is to solve the problem of monitoring image

transmission in 1Km, one of the ways to solve the complex electromagnetic environment situation,

the monitoring image
Signal processing through symmetry mode transmission. Its advantages are: simple, low cost,

wiring resistance to common mode interference performance. The drawback is: can only solve the

1Km
Within the monitoring image transmission, and a twisted pair can only transmit one image, not

suitable for application in large and medium-sized monitoring system; double strand fragile

texture anti-aging
Ability is bad, not suitable for field transfer; twisted pair transmission of high frequency

attenuation is larger, the color of the image will suffer great loss.
6 broadband transmission: is the best solution to solve a few kilometers to tens of kilometers

monitoring signal transmission, using amplitude modulation, frequency modulation with sound
The data signal modulation, FSK and other advanced technologies, the multi-channel monitoring

image, audio, control and alarm signals are integrated into the "a" coaxial visual control cable

bidirectional transmission
Transmission. Its advantages are: make full use of the coaxial cable resource space, multi video

and audio and control signals in the same cable in bidirectional transmission, to achieve

broadband
Co cable "link"; the construction is simple, easy maintenance, save material cost and

construction cost; frequency division multiplexing technique to solve the long distance

transmission point dispersion,
Monitoring image transmission problem of difficult wiring; radio frequency transmission mode only

the signal attenuation, image signal attenuation is small, luminance, chrominance transmission

synchronization nested,
Ensure the quality of the image above grade 4.5 national standards; the 75 coaxial not balanced

way so that it has a strong anti-jamming capability, the complex electromagnetic environment

field
He can still ensure the quality of the image. The drawback is: adopting the weak signal

transmission, broadband modulation end of an AC power supply of 220V, but at present most

monitoring points out
Preparation of this condition.
The above several transmission technique, solves several kilometers or even tens of kilometers in

the monitoring signal transmission should use broadband cable transmission, broadband

transmission cable
Wiring simple, flexible transmission mode, high performance price ratio, strong integration,

integrated image, audio, control and alarm signal for "a" cable, real
The monitoring signal transmission in the program across.