The premise of high-definition surveillance applications is the first issue that needs to be considered after networked acquisition of high-definition pictures is the transmission of video signals. High-definition video places higher requirements on transmission.
One HD video signal needs three coaxial cables to transmit at the same time. Digital transmission generally uses DVI, HDMI, or HD-SDI transmission. The transmission distance of DVI or HDMI is only a few meters, which is not suitable for monitoring and transmission. Although HD-SDI can transmit about 100 meters, it has high requirements for coaxial cables. Cable prices are also very expensive. Whether it is analog or digital transmission, the transmission cost of uncompressed high-definition video signals is significantly higher than that of analog SD video signals. With video compression coding and transmission over IP networks, the difference in transmission costs between high-definition video and standard-definition video is small.
Therefore, it can be seen that high-definition surveillance must first be based on video compression processing and transmitted over the IP network. Only in this way can we effectively control the transmission cost of high-definition video, so that the high-definition surveillance really has practical significance.
The choice of network transmission mode HD video can be selected or constructed according to the network conditions and application scenarios of the system, including network architecture selection (LAN/WAN), transmission mode selection (cable/wireless), transmission media selection (network cable) /optical fiber).
With the maturation and application of wireless and wired broadband technologies such as TD-LTE, Wi-Fi, and private networks, the long-distance transmission of large-volume data is more convenient, which also eliminates the transmission barriers of high-definition network cameras in a wide range of applications.
At present, self-built optical fiber networks or local area networks are usually used to implement 1000M bandwidth networks in projects such as safe cities and financial network monitoring. This kind of Gigabit bandwidth resources, installed in the front-end 100 Road 1080P full-real-time high-definition network cameras (even if calculated by each channel occupying resources 4Mbps), occupying less than 50% of the total bandwidth resources; if you use 720P transmission, the bandwidth can also be reduced by half. In this way, it can fully support the practical application of high-definition network cameras.
Using TD-LTE technology as a quasi-4G mainstream communication technology makes wireless high-definition video transmission possible. TD-LTE (Long Term Evolution) is a technology that has a core independent intellectual property in China and is widely supported internationally. It is a wireless communication standard designed for mobile high-bandwidth applications. According to the definition of TR25.913 of 3GPP, the peak rate of LTE is required to be high, with an uplink of 50 Mbps and a downlink of 100 Mbps.
At the Shanghai World Expo, the TD-LTE demonstration network constructed by China Mobile covered 5.28 square kilometers of the Expo Park. A total of 17 TD-LTE outdoor stations were built, and the indoor coverage of 9 venues was achieved, including 7 venues in Pudong, Puxi. Venues. The demonstration services such as mobile high-definition conferencing, mobile high-definition video surveillance, mobile high-definition video on-demand transmission, and portable video transmission based on the TD-LTE demonstration network are all open to the public and have achieved good results.
The summary should not only be seen, but also clearly seen. With the wide application of video surveillance, people's requirements for video clarity are getting higher and higher. However, only high-definition video capture can not achieve the purpose of high-definition monitoring. The transmission of high-definition video is also a matter of concern. The networked transmission mode and the application of the latest communication technology are the necessary conditions for achieving high-definition monitoring.
One HD video signal needs three coaxial cables to transmit at the same time. Digital transmission generally uses DVI, HDMI, or HD-SDI transmission. The transmission distance of DVI or HDMI is only a few meters, which is not suitable for monitoring and transmission. Although HD-SDI can transmit about 100 meters, it has high requirements for coaxial cables. Cable prices are also very expensive. Whether it is analog or digital transmission, the transmission cost of uncompressed high-definition video signals is significantly higher than that of analog SD video signals. With video compression coding and transmission over IP networks, the difference in transmission costs between high-definition video and standard-definition video is small.
Therefore, it can be seen that high-definition surveillance must first be based on video compression processing and transmitted over the IP network. Only in this way can we effectively control the transmission cost of high-definition video, so that the high-definition surveillance really has practical significance.
The choice of network transmission mode HD video can be selected or constructed according to the network conditions and application scenarios of the system, including network architecture selection (LAN/WAN), transmission mode selection (cable/wireless), transmission media selection (network cable) /optical fiber).
With the maturation and application of wireless and wired broadband technologies such as TD-LTE, Wi-Fi, and private networks, the long-distance transmission of large-volume data is more convenient, which also eliminates the transmission barriers of high-definition network cameras in a wide range of applications.
At present, self-built optical fiber networks or local area networks are usually used to implement 1000M bandwidth networks in projects such as safe cities and financial network monitoring. This kind of Gigabit bandwidth resources, installed in the front-end 100 Road 1080P full-real-time high-definition network cameras (even if calculated by each channel occupying resources 4Mbps), occupying less than 50% of the total bandwidth resources; if you use 720P transmission, the bandwidth can also be reduced by half. In this way, it can fully support the practical application of high-definition network cameras.
Using TD-LTE technology as a quasi-4G mainstream communication technology makes wireless high-definition video transmission possible. TD-LTE (Long Term Evolution) is a technology that has a core independent intellectual property in China and is widely supported internationally. It is a wireless communication standard designed for mobile high-bandwidth applications. According to the definition of TR25.913 of 3GPP, the peak rate of LTE is required to be high, with an uplink of 50 Mbps and a downlink of 100 Mbps.
At the Shanghai World Expo, the TD-LTE demonstration network constructed by China Mobile covered 5.28 square kilometers of the Expo Park. A total of 17 TD-LTE outdoor stations were built, and the indoor coverage of 9 venues was achieved, including 7 venues in Pudong, Puxi. Venues. The demonstration services such as mobile high-definition conferencing, mobile high-definition video surveillance, mobile high-definition video on-demand transmission, and portable video transmission based on the TD-LTE demonstration network are all open to the public and have achieved good results.
The summary should not only be seen, but also clearly seen. With the wide application of video surveillance, people's requirements for video clarity are getting higher and higher. However, only high-definition video capture can not achieve the purpose of high-definition monitoring. The transmission of high-definition video is also a matter of concern. The networked transmission mode and the application of the latest communication technology are the necessary conditions for achieving high-definition monitoring.
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