Adsl2plus Broadband Access System

ADSL2+ is a work in progress at the ITU to standardize a new number in the family of ADSL2 standards.The ADSL2+ recommendation doubles the downstream bandwidth, thereby increasing the data rate on telephone lines shorter than 9 kilofeet.ADSL2+ is expected to reach consent at the ITU in early 2003. While the first two members of the ADSL2 standards family G.992.3(G.dmt.bis) and G.992.4(G.lite.bis) specify a downstream frequency band up to 1.1 MHz and 552kHz respectively,ADSL2+ specifies a downstream frequency up to 2.2MHz.The result is a significant increase in data rates on shorter phone lines. ADSL2+ also provides an optional mode that doubles the upstream bandwidth which will also provide a doubling of the upstream data rate.ADSL2+ can also be used to reduce crosstalk. ADSL2+ provides the capability to use only tones between 1.1MHz and 2.2MHz by masking the downstream frequencies below 1.1MHz.This can be particularly useful when ADSL servers from the central office(CO) to a remote terminal(RT) are present in the same binder as they approach customer's homes .The crosstalk from the ADSL services from the RT onto the lines from the CO can significantly impair data rates on the lines from the CO.ADSL2+ can be used to correct this problem by using frenqucy below 1.1MHz from the central office,and frequencies between 1.1MHz and 2.2MHz from the remote terminal to the custormer premise .This will eliminate most of the crosstalk between the services and preserve data rates on the line from the central office. This project is to realize the ADSL2+(G.992.5) on media access device of HW-MA5300.The ADSL2+ model relies on the ADSL model of the HW-MA5300 and is compatible with it.