Before I comment anything about ADSL 2+,i would like to share some information regarding ADSL.
1.What is ADSL?
Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call.ADSL can generally only be distributed over short distances from the central office, typically less than 4 kilometres.
2.Frequency of ADSL:
The public switched telephone network (PSTN) is the network of the world's public circuit-switched telephone networks.
4.What is ADSl 2+?
As shown in the standards of ADSl,ADSL 2+ is the new format which is been used,not widely though.
ITU G.992.5 is an ITU (International Telecommunication Union) standard, also referred to as ADSL2+ or ADSL2Plus.
Commercially it is notable for its maximum theoretical download speed of 24 Mbit/s.
ADSL2+ extends the capability of basic ADSL by doubling the number of downstream bits. The data rates can be as high as 24 Mbit/s downstream and 1.4 Mbit/s upstream depending on the distance from the DSLAM to the customer's home.
ADSL2+ is capable of doubling the frequency band of typical ADSL connections from 1.1 MHz to 2.2 MHz. This doubles the downstream data rates of the previous ADSL2 standard of up to 12 Mbit/s, but like the previous standards will degrade from its peak bitrate after a certain distance.