System to provide real loops for sidetone measurement with analog telephones

摘要

A real loop and method for using the loop for testing sidetone signal level are provided. The loop is modeled from a coil of cable to represent a straight wire loop. Several conducting wires in a cable may be used. The cable may be configured in a coil and may have a first end and a second end exposed for electrical connections to an even number of wires. Each wire in the even number of wires may be capable of being identified as the same wire on each of the first and second ends of the cable. One or more pairs of wires in the even number of wires may be electrically connected to form an electrical loop. An electrical current passes in opposite directions in the wires in each pair of wires.

主权项

1. A method for testing sidetone signal strength, the method comprising:
providing a loop modeled from a single coil of cable and representing a straight wire electrical loop existing between a telephone and a central office in a telephone network, comprising:
a plurality of conducting wires in a single cable having a first length, which first length is greater than or equal to 1000 feet, wherein the cable is configured in a single coil wound in a single direction and having a first end and a second end exposed for electrical connections to an even number of wires therein, wherein each wire in the even number of wires is capable of being identified as being the same wire on each of the first and second ends of the cable, and wherein at least one pair of physically adjacent wires comprising at least a first wire and a second wire in the even number of wires are electrically connected to form an electrical loop including the at least one pair of physically adjacent wires, wherein the first wire has a first insulation type and the second wire has a second insulation type, and wherein the first insulation type imparts at least one electrical characteristic to the first wire which is materially different than a corresponding electrical characteristic imparted by the second insulation type to the second wire, wherein a length of the electrical loop is at least twice the first length of the cable, wherein fewer than all of the plurality of conducting wires in the cable are electrically connected to form an electrical loop and wherein an impedance of the loop is representative of an impedance of an electrical loop existing between a telephone and a central office in a telephone network; coupling a communication device capable of producing a signal including a sidetone signal to the loop; providing the signal in the loop; and measuring a strength of the sidetone signal at the communication device to form a measured sidetone strength.