ATM technology for broadband communication (1)

Asynchronons transfer mode (ATM) is a communication mode that integrates transmission and exchange. ATM has become a key technology for broadband communication in the 21st century. It has been determined by ITU as a basic transmission method for Broadband Integrated Business digital networks. At the beginning of the 9O era, the development of computer networks and the accelerated commercialization of network transmission media optical fiber and multimedia technologies. Traditional network technologies, such as Ethernet, fast Ethernet, and FDDI, cannot meet the needs of users in terms of transmission speed and connection methods.

The emerging ATM technology is a new information transfer mode developed based on the traditional circuit transfer mode and group transfer mode. It features fast transmission speed and unlimited distance. It integrates voice, image, and sound transmission features, and is especially suitable for multimedia applications.

ATM is a transmission method that combines two advantages: Circuit Switching and group switching. It uses a 53-byte fixed cell exchange technology, which has the characteristics of adjustable bandwidth and high speed of group switching, as well as low latency of circuit switching and credit exchange. Due to the fixed cell byte, the hardware exchange technology can be used to select routes.

The ATM switching technology is applicable to LAN) and WAN) to provide users with a unified network technology solution. The traditional WAN technology is different from the current LAN technology. When the LAN and WAN are connected, a router is required for protocol exchange. The existing ATM technology supports different speed specifications such as 622 M, 155M, and 25 M, among which 155MbpS is currently the most mature technology.

The main advantage of ATM technology is that digital services at different rates, such as data, voice, high-resolution images, and broadband TVs, are transmitted over the same network in broadband communication, the information is disassembled and converted into 53 fixed-length cells, of which 48 bytes are valid information and 5 bytes are header or cell header, header to store the transmission address information), and then perform fast group exchange to meet the needs of different business transmission.

The high speed of ATM is to process fixed-length cells. The cell length is short and the delay time is small. The total throughput can be from 2.5 Gb/s to IOGb/s, can meet the needs of LAN and WAN. The commonly used Ethernet is only 1 Omb/s, and the licensing ring is only 16 Mb/s. With its high throughput, ATM becomes the best connection method that can work with different bandwidths and multiple devices.

The broadband ATM communication network is a modern communication network that provides users with high-speed access, high-speed exchange, and high-speed transmission based on the Broadband ATM technology. Compared with the various narrowband multimedia communication networks established in China, this network has more advanced and advantageous advantages, it can implement a variety of information services such as data, images, remote teaching, remote medical care, remote shopping, video conferences, and on-demand video, these services are interactive, dynamic, and mobile. They are a key step to realizing the information highway in the true sense.

China's research and development in the field of group exchange and Telephone Exchange started late, basically there is no competition between domestic equipment and imported equipment. At present, the world's ATM has not been fully commercialized, and China has achieved success in the atm r & D field. Among them, there are representative Beijing University of Posts and Telecommunications developed by the BTC-9500 Institute of Telecommunications Science and Research Gao Hong ATM switch, electronic Department 54th Research Institute developed access ATM switch.