Discussion on access network technology and network access mode structure

There are many areas worth learning about the access network technology. Here we mainly introduce the access network technology and network access mode structure. The access network technology refers to all the cabling equipment (Physical location of the access network) between the Exchange Board and the user terminal. The main system is a traditional cable and optical cable, which is generally several kilometers long; the wiring system may also be a cable or optical cable. Its length is usually several hundred meters, and the introduced line is usually several meters to dozens of meters.

According to ITU-T, the access network is composed of a series of transmission entities (such as line facilities and transmission facilities) between the business contact interface (SNI) and the relevant user network interface (UNI, an implementation system that provides the required transmission capacity for the data transmission service. It can be configured and managed through the Q3 interface. The transport entity provides the necessary transfer carrying capacity, which is transparent to user signaling and is not processed. It can be regarded as a transmission network unrelated to services and applications. It mainly performs cross-connection, multiplexing, and transmission functions, and generally does not include the exchange function.

The structure of the network access method, collectively referred to as the network access network technology, takes place in the last section of the Connection Network and the user, the network access network technology is currently the most promising link to greatly improve network performance. This is a bottleneck for the local road network. There are hundreds of millions of user access lines around the world, and their limited functions hinder the development of network user services, in contrast to the high-performance devices at the other end of the user line. With the rapid development of electronic and optoelectronic technologies, the performance of digital electronic systems from personal computers to network switches or routers is growing rapidly and steadily, it provides broad development prospects for solving the bottleneck of this loop. Since the copper line in the local loop still transmits analog signals, people still use narrow radio channels to traverse the crowded radio spectrum.

At present, how to expand the network access bottleneck to provide ultra-broadband for the existing 0.75 billion access lines in the world has become the focus of network technology development. The bottleneck is relative, A pair of metal wires can provide enough capacity to support two-way conversations, but the bandwidth provided by traditional copper wires is indeed difficult for high-performance data networks and the Internet. Data Users not only want to talk to each other, in the hope that the virtual images of the other party can be seen through the video conferencing system, the traditional access network technology (access mode, access wiring) requires high performance to break through the bottleneck of network access. In order to increase the bandwidth in the last segment of the network, and to meet the communication requirements of users in the home or small office in a wide range. The bottleneck of the local loop is caused by the low bit rate provided today. In fact, apart from the bandwidth restrictions of the local loop, the current data network technology is sufficient to provide motion images and other high-bandwidth services.