Testing system of voice-band data transmission interface on an exchange
AssigneeFujitsu Limited
InventorHisashi Amagasaki
Life of this patent
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Abstract
According to the present invention, a maintenance operator can optionally or automatically test not only normality of a frequency shift keying (FSK) signal calling circuit but a specification, a transmission protocol and a standard of a signal length of FSK signal. An exchange system for transmitting information, such as a caller number, to a subscriber line circuit by employing a frequency shift keying signal, the exchange system comprising: a loop circuit for imitating a loop of a subscriber's telephone set; and a firmware for receiving a frequency shift keying signal and judging the normality of the frequency shift keying signal, wherein the firmware controls to open and close the loop circuit according to testing on On-Hook or Off-Hook protocol.
Claims7
An interface testing system for use in transmitting data within a voice band, the interface testing system comprising:
- an exchange for transmitting information including a caller number to a subscriber line circuit, to which customer premise equipment is connected through a telephone line;
- a caller line identification transmitter provided in the exchange for transmitting a frequency shift keying signal which is modulated with the transmission information including a caller number;
- a loop circuit attached to the exchange for turning back the frequency shift keying signal output from the caller line identification transmitter so as to imitate a loop of a subscriber's telephone set, which is connected to the customer premise equipment;
- and
- a firmware provided in the exchange for receiving a the frequency shift keying signal turned back from the loop circuit and controlling to open and close the loop circuit according to testing of an On-Hook or Off-Hook protocol to judge the normality of the frequency shift keying signal.
An interface testing system for use in transmitting data within a voice-band, the interface testing system comprising:
- an exchange for transmitting information including a caller number;
- a called line identification transmitter provided in the exchange for transmitting a frequency shift keying signal, which is modulated with the transmitting information including a caller number;
- a subscriber circuit including a circuit attached to the exchange for turning back the frequency shift keying signal output from the called line identification transmitter;
- and
- test equipment attached to the exchange for receiving the frequency shift keying signal turned back by the turning back circuit and for performing testing of whether or not the frequency shift keying signal follows protocols of On-Hook or Off-Hook status.
Dependencies are inferred from the claim text.