Abstract: The length and attenuation of a signal line between a transmitter and a customer premises equipment is to be estimated. A frequency dependent line input impedance (Zin(f)) as seen from the transmitter, is measured and an absolute impedance value (œ Zin(f) œ) is generated. The latter is shown as a curve (A1) in the diagram with the frequency (f) on the abscissa and the impedance (œ Zin(f) œ) on the ordinate. Extreme values (Max.1, Max2, Max3; Min1, Min2, Min3) arc denoted and a frequency distance (FD1-FD4) between two consecutive of the extreme values is generated. The line length (L) is generated as L=½·vop/FD1, in which vop is the velocity of propagation of a signal on the line. The attenuation is estimated by multiplying the line length with an average attenuation value for the actual line type. The advantages are that the line length can be estimated with good accuracy in a simple manner for short lines and that the line attenuation is estimated in a simple manner.

Abstract: The length and attenuation of a signal line between a transmitter and a customer premises equipment is to be estimated. A frequency dependent line input impedance (Zin(f)) as seen from the transmitter, is measured and an absolute impedance value (œ Zin(f) œ) is generated. The latter is shown as a curve (A1) in the diagram with the frequency (f) on the abscissa and the impedance (œ Zin(f) œ) on the ordinate. Extreme values (Max.1, Max2, Max3; Min1, Min2, Min3) arc denoted and a frequency distance (FD1-FD4) between two consecutive of the extreme values is generated. The line length (L) is generated as L=½·vop/FD1, in which vop is the velocity of propagation of a signal on the line. The attenuation is estimated by multiplying the line length with an average attenuation value for the actual line type. The advantages are that the line length can be estimated with good accuracy in a simple manner for short lines and that the line attenuation is estimated in a simple manner.

Abstract: The invention refers to single-ended test of a loop with the aid of a transceiver, wherein an input impedance (Zin(ƒ)) of the loop is generated. The transceiver has a digital part, a codec and an analog part and is connected to the loop. With the aid of a transmitted and a reflected broadband signal (vin, vout) an echo transfer function Hecho(ƒ)=V(f)out/Vin(f) is generated, which also can be expressed as H echo ? ( f ) = H ? ? ( f ) ? Z in ? ( f ) + Z h0 ? ( f ) Z in ? ( f ) + Z hyb ? ( f ) . Here Zh0(ƒ), Zhyb(ƒ) and H?(ƒ) are model values for the transceiver. In a calibration process a test transceiver, with the same type of hardware as the transceiver, is connected to known impedances, replacing the loop. Hecho(ƒ)=V(f)out/Vin(f) is generated for the known impedances and the model values are generated and are stored in a memory in the transceiver.

Abstract: The invention refers to single-ended test of a loop with the aid of a transceiver, wherein an input impedance (Zm(ƒ)) of the loop is generated. The transceiver has a digital part, a codec and an analog part and is connected to the loop. With the aid of a transmitted and a reflected broadband signal (vin, vout) an echo transfer function Hecho(ƒ)=V(f)out/Vin(f) is generated, which also can be expressed as H echo ? ( f ) = H ? ? ( f ) ? Z in ? ( f ) + Z h0 ? ( f ) Z in ? ( f ) + Z hyb ? ( f ) Here Zh0(ƒ), Zhyb(ƒ) and H?(ƒ) are model values for the transceiver. In a calibration process a test transceiver, with the same type of hardware as the transceiver, is connected to known impedances, replacing the loop. Hecho(ƒ)=V(f)out/Vin(f) is generated for the known impedances and the model values are generated and are stored in a memory in the transceiver.