Practical application of remote video surveillance systems in Broadband Access Networks

There are many things worth learning about broadband access networks. Here we mainly introduce the practical application of remote video surveillance systems in broadband access networks. Today, as human society is about to enter the information society, the development of telecommunication networks and computer networks has greatly changed the way people live in the whole society, in turn, the change in people's lifestyles puts forward higher requirements on the service capabilities of computer networks and telecommunications networks.

Since 1990s, with the rise of the Internet and the popularity of personal computers, the number of Internet users and data services represented by IP addresses have experienced explosive growth. At the same time, a large number of new business needs have emerged, such: video conferencing, e-commerce, VOD, etc. These new business requirements put forward new requirements for network bandwidth. The advancement of OA and DWDM technologies, as well as the emergence of ATM, MPLS, and Tbps routers provide timely means for upgrading transmission networks and exchange networks, the bandwidth bottleneck lies in the broadband access network.

With the emergence and development of different systems and various solutions based on different transmission media, such as xDSL, HomePNA, WLL) the broadband access network has been unprecedentedly developed for Systems Based on Coaxial Cable (HFCs) and CableModem (OAN. The development of broadband access networks has in turn promoted the emergence and development of new business needs. Remote monitoring is one of them.

Remote Monitoring and Image Compression

In the past, only banking and financial institutions, Wenbo, and other enterprises and institutions had this service requirement. Most of them were based on traditional access methods, such as DDN, V.90Modem, and ISDN broadband access networks, perform remote and centralized monitoring on the data center of bank financial institutions and telecom operators.

Now, with the broadband access network, remote monitoring is no longer an inaccessible service for families. With the development of broadband access networks, it will flourish as a new service of access networks, bring New Family feelings to people. As the main monitoring content of remote monitoring, images need to focus on the solution because of the large amount of data. If the image problem is solved, other data, such as home theft and records of entry and exit personnel, will also be solved.

Image Compression Method

At present, there are many methods of image compression coding, and the development is quite rapid. Typical coding methods include Huffman coding, arithmetic coding, predictive coding, and transform domain encoding. Considering that the characteristics of human visual perception are inconsistent with the information distribution in the statistical sense, the so-called "Perception entropy" theory is introduced, along with the mathematical theory, such as wavelet transform and the in-depth development of relevant disciplines have produced modern coding methods, also known as analysis and synthesis methods. Based on the above two encoding methods, international standards for various image compression coding based on different application purposes have been released.

To sum up, there are H.261, H.263, H.264 recommendations, JPEG Standards as well as MPEG-1, MPEG-2, MPEG-4 standards. MPEG standards are MPEG-7, MPEG-21 and so on. MPEG-1/2/4 is a system-level standard, which not only has video encoding, but also has audio encoding and system layer protocol content, including multiplexing and synchronization time base and so on. H.261 and H.263 are only video encoding standards and must be compatible with other related international standards and recommendations.

H.261 is mainly used for videophone/conference television, H.263 is used to simulate videophone/teleconference over telephone lines, while JPEG is mainly used for transmission of high-resolution static images and low-resolution images. H.262 and MPEG in the same series as H.261/3 serve as the draft ISO/IEC13818 standard. The draft standard is mainly used for digital storage, video broadcast and communication. The storage media can be connected either directly to the decoder or through a bus, LAN, or Telecom link. The MPEG-1 standard is used to encode active images and their sound on a digital storage body with a digital rate of 1.5 Mbps. MPEG-1 has made significant improvements on the basis of H.261 to meet the requirements of random access and high compression ratio. Its image scanning format is SIF (SourceInputFormat) format and serves as the standard of VCD.

The title of the MPEG-2 is "generic encoding of active images and associated sound information", which can be understood as further expansion and improvement on the basis of the MPEG-1. At present, MPEG-2 has been recognized by the world, it is the basic standard of sound and image signal digitalization has been widely used. The "Scalability" concept is introduced to implement hierarchical video compression and encoding. Including the main level ITU-RBT.601/D1 format, HDTV level advanced wide screen/narrow screen format and so on.