A New Approach of Digital Subscriber Line2 Initialization Process

In this paper, a design for Asymmetric Digital Subscriber Line (ADSL)/Asymmetric Digital Subscriber Line2 (ADSL2) Initialization Process is presented which can be applied to different telephone network. Such a proposal can face the different types of noise over DSL channels, the most important types are Background and Crosstalk noises and Inter symbol interference (ISI) which is eliminated by using Time Domain Equalizer (TEQ). The Minimum Mean Square Error (MMSE) algorithm is implemented as TEQ algorithm. The initialization process where tested on American National Standard Institute (ANSI) defines 8 Carrier Serving Area (CSA) test loops for ADSL service. As a result, 9.02 Mbps and 9.42 Mbps were achieved over CSA loop-2 for ADSL and ADSL2 respectively. The TEQ efficiency for 8 CSA test loop are calculated where it achieved 93.1% of zero ISI for CSA loop-3. A comparison between Near End Cross-Talk (NEXT) and Far End Cross-Talk (FEXT) power shows that NEXT have higher power and narrow band where NEXT powers were (-45.593) dBm for all loops and FEXT were ranging from (-76.353 to -68.261) dBm for the 8 loops. Finally the results show that ADSL2 outperforms ADSL by about 400Kbps which about 1.1%.