Method and system for adaptively adjusting modem operating characteristics

A modem adaptable for use under a variety of operation specifications, the modem comprising, in combination:

• (a) a circuit for interfacing with a telephone line, the circuit having at least one selectively adjustable electrical characteristic using a selectively variable impedance circuit comprises a gyrator circuit having an adjustable impedance;
• and
• (b) control logic coupled with the circuit, the control logic arranged to:
• (i) measure an electrical characteristic on the telephone line, and
• (ii) in view of the measured electrical characteristic on the telephone line, determine whether the modem is operating in compliance with a particular operation specification, and, in response to a determination that the modem is not operating in compliance with the particular operation specification, adjust the at least one electrical characteristic of the circuit so as to change the electrical characteristic of the telephone line to thereby bring the modem in compliance with the particular operation specification.

In a modem having a circuit for electrically interfacing with a telephone line, the circuit defining an impedance with respect to the telephone line, the circuit being selectively switchable between an off hook state with respect to the telephone line and an on hook state with respect to the telephone line, a method for adaptively configuring an operating state of the circuit comprising the following steps:

• (a) when the modem is in the on-hook state, setting an off hook impedance of the circuit to a first impedance level;
• and
• (b) subsequently, when the modem is in the off-hook state,
• (i) measuring a first voltage level on the telephone line at the modem,
• (ii) determining whether the first voltage level is lower than a predefined threshold voltage level,
• (iii) in response to a determination that the first voltage level is lower than the predefined threshold voltage level, changing the impedance of the circuit to a second impedance level lower than the first impedance level;
• and
• (iv) computing a first current level based on the first impedance level and the first voltage level,
• (v) determining whether the first current level exceeds a predefined threshold current level, and
• (vi) in response to a determination that the first current level exceeds the predefined threshold current level, modifying the impedance of the circuit to a third impedance level different than the first impedance level.

A modem comprising, in combination:

• a line interface circuit having a selectively configurable arrangement of electrical components including a selectively variable impedance circuit comprises a gyrator circuit having an adjustable impedance;
• means for measuring an electrical characteristic of a telephone line to which the modem is connected;
• means for determining whether the electrical characteristic of the telephone line exceeds a predefined threshold;
• and
• means for selectively configuring the arrangement of electrical components in response to a determination that the electrical characteristic of the telephone line exceeds the predefined threshold.

A modem comprising, in combination:

• a processor;
• a memory;
• a first circuit for interfacing with a telephone line, the first circuit having an arrangement of electrical components including a selectively variable impedance circuit comprises a gyrator circuit having an adjustable impedance selectively configurable into a first state in which the first circuit has a first electrical operating characteristic with respect to the telephone line and a second state in which the first circuit has a second electrical operating characteristic with respect to the telephone line;
• a second circuit for measuring an electrical characteristic of the telephone line and providing to the processor a first signal indicative of the electrical characteristic of the telephone line;
• and
• a set of machine-readable instructions stored in the memory and executable by the processor for (i) receiving the first signal, (ii) responsive to the first signal, determining whether the electrical characteristic of the telephone line exceeds a threshold electrical characteristic and, (iii) in response to a determination that the electrical characteristic of the telephone line exceeds a threshold electrical characteristic, sending a signal to the first circuit to cause the first circuit to switch from the first state to the second state.