Complete a DSL Advanced Configuration

Power Spectrum Distribution

The Power Spectral Density (PSD) plots the variations of signal power with signal frequency for the G.shdsl transmission between the modem and the DSLAM or the modem and another modem. Symmetric PSD indicates that the PSD mask for both sides of the transmission (the CO- and remote-side) are the same (symmetric).

Asymmetric PSD indicates that the PSD mask for both sides of the transmission (the CO- and remote-side) are not the same (asymmetric). There are two unique numeric values (AsymmetricRate1 and AsymmetricRate2) used to determine the asymmetric PSD mask based on the Annex A or Annex B standard that you selected (see page 60). AsymmetricRate1 is 784 kbps for Annex A and 2312 kbps for Annex B. AsymmetricRate2 is 1552 kbps for Annex A and 2056 kbps for Annex B.

Both ends of the connection must be set for the same Symmetric or Asymmetric PSD. The default is Symmetric.

Bit Rate Mode

Bit rate mode indicates how the modem synchronizes with the device to which it is attached in either a Fixed or Adaptive mode. The default for the MM702G modem is Fixed mode. The default for the MM701G modem is Adaptive mode.

•Fixed mode indicates that the modem will synchronize with the other end (a DSLAM or another modem) at a fixed bit rate through negotiation. The modem will synchronize at the best rate, up to the data rate specified (page 61), that can be achieved by both ends.

•Adaptive mode indicates that prior to modem negotiating a rate, the modem performs an adaptation phase during which it determines a best possible rate based on conditions of the line. After adaptive mode, the modem will then negotiate the best rate that can be achieved with the other end, based on the adaptation results. An MM702G in Dual Wire Pair Mode cannot be used in Adaptive Bit Rate Mode.

Test Bit Rate

This bit rate is used by the manufacturer for internal use only.

SNR Margin Limit

Identifies the minimum SNR margin (in decibels) that must exist when the G.shdsl connection is synchronized and in order for the DSL MAR LED to be lit ON Green. The range of values is -64 to 63. The default value is 4.

3Click Apply then save changes using “Saving Changes” on page 53.

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MM701G and MM702G User Manual