ADSL Transport Capacity

The different ADSL transport classes for n2.048 Mbps bearers are 2M-1, 2M-2 and 2M-3. In which 2M-1 corresponds the highest rate and shortest range.

ADSL downstream transport capacity is basically from 2.048 Mbps to 6.144 Mbps. At 6.144 Mbps it is possible to achieve the range of about 3 kilometers [1]. The lower the transmission rate is the longer the range will be. Upper limit is according to tests about 9 kilometers [2]. It is possible to achieve higher data rates of 52 Mbps and 155 Mbps, corresponding range of one mile and a quarter mile, if the used transmission media is fiber [1]. By using DMT ADSL it is also possible to use other data rates, the exact rate depends only on interface circuits. So the system is flexible enough to support, eg., T1. The downstream bit rates are summarized in table .

  
Table: Downstream bit rates

ADSL upstream transport capacity is 0 -- 640 kbit/s depending on transport class. The aggregate upstream bit rates are summarized in table .

  
Table: Upstream bit rates

ATM can be transported over ADSL and the components of the aggregate bit rates are summarized in table .

  
Table: ATM bit rates