Main features of ADSL technology

DSL (digital subscriber lines, Digital subscriber line) is a copper telephone line for transmission medium transmission technology combination, it includes HDSL, SDSL, VDSL, ADSL and RADSL, etc., generally referred to as xDSL. Their main difference is reflected in the signal transmission speed and distance, as well as the uplink and downlink rate of the different symmetry of the two aspects.

HDSL and SDSL support symmetric t1/e1 (1.544mbps/2.048mbps) transmissions. The effective transmission distance of HDSL is 3-4 km, and it needs two to four pairs of copper twisted telephone lines; SDSL maximum effective transmission distance of 3 km, just a pair of copper wire. In comparison, symmetric DSL is more suitable for enterprise point-to-point connection applications, such as file transfer, video conferencing and other data to send and receive roughly the corresponding work. Compared to asymmetric DSL, the market for symmetric DSL is much lower.

VDSL, ADSL and RADSL belong to asymmetric transmission. VDSL technology is the fastest of xDSL technology, on a pair of copper twisted telephone line, uplink data rate is 13 to 52Mbps, downlink data rate of 1.5 to 2.3 Mbps, but the VDSL transmission distance of only hundreds of meters, VDSL can be a cost-effective alternative to the fiber to the home, the current Shenzhen VOD (video on Demand) is implemented by this access technology; ADSL supports up to 640Kbps to 1Mbps on a pair of copper wire, downlink rate 1Mbps to 8Mbps, Effective transmission distance within 3-5 km range; RADSL can provide the same speed range as ADSL, but it can dynamically adjust the user's access speed according to the quality of twisted-pair copper wire and the distance of transmission. It is the RADSL of these features that make RADSL the ideal technology for high-speed surfing on the web, video-on-demand (IAV), remote local area network (LAN) access, where users often download much more information than the uploaded information (send instructions).

ADSL Access Service can achieve higher performance price than this, and ADSL access technology than other access technology has its unique technical advantages is inseparable.