Sagem 4450E - Manual (Page 158)

CHAPTER 12
3P@C Installation Manual
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12. Line Commissioning and Maintenance
12.1. Commissioning and Maintenance of ADSL
Subscriber Line
12.1.1. ADSL Technical Parameters
1.1.1.57 ADSL Signal Frequency Range
ADSL splits the frequency band through the passive splitter, realizing the common transmission of voices and
data on the twisted pairs, its signal frequency range is shown as follows:
Figure 12-1 Frequency range of ADSL
Upstream
Downstream
Frequency
In this case:
„ ADSL upstream signal frequency band: 26KHz—138KHz
„ ADSL downstream signal frequency band: 138KHz—1104KHz
„ Telephone audio frequency band: 300Hz— 3,400Hz
ADSL uses the Discrete Multi-Tone (DMT), and each carrier channel is relatively independent, the occupied
frequency band width is 4.3125KHz, and each carrier can transmit the data of 0-15 bits in the signal transmission
stage. Within the range of 0-1.1MHz, it is divided into 256 sub-carrier channels.The application and division of
ADSL is shown in the figure below:
Figure 1-1 ADSL carrier channel application and division
Frequency
Here:
„ US indicates Upstream