Telephone line service type identification is provided to a telephone
technician in the field by the placement of one or more tuned circuit(s) across the
telephone line. In one embodiment, an inexpensive tuned circuit such as a
ceramic resonator forms a telecom service
resonator ID device which is placed across a
telephone line, either at the central office or at the customer premises. Injection of a test current at a predetermined frequency, and a suitable amplitude of the same indicates to the
technician aspects of telecom service to that particular
telephone line (e.g., the existence of POTS, ISDN, and / or xDSL) and or use of the telephone line by a home network such as HPNA. In another embodiment, a telecom service
transponder ID device is formed to provide line service identification to an interrogating line
technician. The telecom service
transponder ID device is activated when the test
signal including an appropriate frequency is present to cause excitation in the telecom service
transponder ID device. The
resonator and transponder devices preferably have very high impedances at all frequencies except at the desired resonant frequency, and thus avoids violation of telephone service standards. The resonator or transponder ID devices may be placed anywhere along the telephone line, but preferably at the customer premises, or in installed equipment utilizing the telephone line. More than one resonation frequency may be implemented with parallel tuned circuits to indicate additional features of service on the telephone line (e.g., the number of services, the existence of a data service, etc.). The frequencies of
resonance of the tuned circuits are preferably chosen to exist between the spectrum utilized by the various operating services. The transponder implementation may generate a simple
low frequency response
signal, or a more sophisticated specific data pattern using amplitude and / or
frequency modulation.