ADSL modems can create multiple channels to transfer data. For this, ADSL modems divide the available bandwidth of a telephone line in one of two ways - Frequency Division Multiplexing (FDM) and Echo Cancellation. The FDM assigns one band for upstream data and assigns another band for the downstream data. Further, the downstream path gets sub-divided into one or more high-speed channels by time division multiplexing. Similarly, the upstream path also gets multiplexed into corresponding low-speed channels. Echo Cancellation enables the upstream band to overlap the downstream band. These two bands get separated by means of local echo cancellation. Both Frequency Division Multiplexing (FDM) and Echo Cancellation techniques enable ADSL to split off a 4 kHz region for POTS at the DC end of the band. | 
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| With ADSL, subscribers can now get up to 6 Mbps of data in one direction, or about 832 kbps or more data in both directions. These rates of expansion enable the expansion of existing access capacity by a factor of about 50 or more. And that too, without the need for new cabling. The ADSL circuit uses an ADSL modem on each end of the twisted-pair telephone line. | 
