CHAPTER 12

12.Line Commissioning and Maintenance

12.1.Commissioning and Maintenance of ADSL Subscriber Line

12.1.1.ADSL Technical Parameters

1.1.1.57ADSL 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 1-1ADSL carrier channel application and division

Frequency

Here:

„US indicates Upstream

3P@C Installation Manual

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