ADSL Progress

There are couple of interesting prospects in the future of ADSL. The development of High-Speed ADSL is on its way. There are also proposals for in-house extensions of ADSL. The interconnections of ADSL-systems and Broadband Services are also under study.

Below are listed a few points to take into account, when the progress of ADSL DMT-systems is consider.

1. Speed up
   • 6 Mbps is not enough
   • n DMT
   • by using 8 DMT 51.84 Mbps over a mile possible
2. Broadband services
   • ATM over ADSL or within ADSL ?
3. DIM (DMT Information Bus)
   • A possible in-house extension for ADSL

  
Figure: Multidrop extension example of ADSL

The DMT Information Bus (DIB), see figure , is based on the fact, that ADSL DMT modems can interoperate on the common subchannels. The central-office modem can ``talk'' to severeal remote modems simultaneously. Of course the remote modems need to be loop-timed in sample and symbol clock. This kind of approach has the advantage, that no in-house rewiring is needed. [1]