Discrete Multi-Tone (DMT) describes a version of multicarrier DSL modulation in which incoming data is collected and then distributed over a large number of small individual carriers, each of which uses a form of QAM modulation. DMT creates these channels using a digital technique known as Discrete Fast-Fourier Transform. By varying the number of bits per symbol within a channel, DMT carriers can also be rate-adaptive. Both ITU 992.1 (G.dmt) and ITU 992.2 (G.lite) use a form of DMT modulation for data transmission. The DMT Technical specification is outlined ANSI Standard T1.413, and it is capable of transmission speeds of up to 8064 Kbps downstream and 1024 Kbps upstream.