What is the difference between ADSL and ADSL2?

ADSL is an internet connection technology which was first introduced in 1998 and went on to know a series of further developments.

The acronym stands for Asymmetrical Digital Subscriber Lines. This kind of technology uses copper lines also utilised by telephone communications. Therefore, it offers great data transmission speeds without requiring the installation of newer physical lines, because this technology relies on the historical phone network.

Because of their being asymmetrical, these lines enjoy much higher downstream speeds than upload speeds – but they are fine for most of private users whose needs consist much more of downloading than uploading.

Contrary to what many consumers believe, ADSL technology has known many evolutions, mostly in terms of speed and reliability. Thus, ADSL2 represents worth-noticing improvements over the primary version. But which ones actually?

One of the soft points of the ADSL technology has always been that the further the user is from the telephone exchange, the slower his connection. The ADSL2 technology was introduced in 2002, and has enjoyed newer developments until 2005. Among other enhancements, this newer standard improved the distance the line can reach from the exchange to the end user and the resistance to noise. Besides, it introduced dynamic data rate adaptation, a standby mode, and reduced the initialisation time from 10 seconds down to less than 3 seconds.

From the first main generation of Asymmetrical Digital Subscriber Lines to the latest evolution of the second, download speeds have increased from 1.5 megabit per second to 25 mb/s, and upload speeds from 0.5mb/s to 3.3mb/s.