With the development of technology, mobile voice and data communications systems have been popular, more and more users will shift the focus to move to the video above. In some special industries such as: military, public security, armed police fire and other industries, growing demand for mobile information systems, the system will not only need to be resolved on-site images, mobile voice transmission, but also require real-time two-way transmission of data, database information inquiries.
Based mobile applications through a wireless link can only be achieved, but now widely known as spread spectrum microwave Although high-bandwidth, but limited to high-frequency points, can be visual communication, which requires fixed-point wireless transmission applications can still be used for moving vehicles in terms of high frequency wireless base can not use the vehicle in motion, may go through different obstacles affecting wireless transmission. And when the vehicle reaches a certain level of distance to the center, due to curvature of the earth and the ups and downs of the ground, between two points has been unable to guarantee the visual conditions, high frequency radio equipment has not work. Also in the city, especially some of the larger cities, due to high-rises, the center can not provide vehicle wireless visual environment, and mobile video is very difficult, and general narrow-band products, although with low frequency, around shooting ability, the characteristics of transmission distance, but a lower rate of image transmission is difficult to meet the requirements.
iNET The device uses advanced radio frequency-hopping spread spectrum technology, equipment, very strong anti-interference ability. Using special encryption, strong safety performance. Work on 340MHz radio frequency band, low frequency, has a strong penetration capability and diffraction, transmission distance, and because the station uses digital signal processing technology and FEC Forward Error Correction technology, it has a high signal reception sensitivity and can guarantee a reliable signal transmission to make it more difficult to adapt to urban wireless environment is the case of the application. Radio air transmission rate of up to 512/256kbps, to meet the general image of the requirements over the same time providing a device Ethernet port, two serial ports, with video servers and other devices that can provide images, voice and data solutions.
INET radio transmission rate for the situation is not very high, and the need to transmit voice, data, we chose the H.264 video server that uses the world's most advanced field of video transmission technology, has a very high image compression , and the technology for easy wireless packet loss, bit error correction and other features provide the appropriate tools.
As iNET radio with the above characteristics, we can put a tower on the center of 8.5dBi omni-directional antenna, moving vehicles on the car put a 5.6dBi antenna, in the case of line of sight transmission distance of 50KM can guarantee, if must stop the case, promised more than ten km radius of several kilometers to the site within the real-time transmission of images back to command center. To achieve the mobility of mobile video systems and video transmission in real time, on-site command center to improve the efficiency of the command. At the same time, on-site staff can also set special networks of real-time wireless access to the internal network, relevant data files, to achieve on-site office, greatly improve work efficiency.
System Architecture
