摘要:
A telecommunications system provides telephone services to subscriber locations over dedicated optical fibers which extend in a “star” configuration from a telephone central office. A transmultiplexer installed at the central office is connected between a digital switch and the optical fibers. The transmultiplexer has a plurality of FDM ports, each of which is connected to a respective one of the optical fibers. The transmultiplexer is connected by one or more TDM ports to the digital switch. Preferably, the transmultiplexer provides a concentrating function whereby the number of subscriber lines served by the transmultiplexer is greater than the total voice-grade channel capacity of the connection between the transmultiplexer and the digital switch.
摘要:
A system for voice distribution amongst a plurality of telephone subscriber locations operating on a broadband cable network wherein RF transmitting and RF receiving channels for carrying voice and signalling information are established at the subscriber locations and coupled with the broad band network and a central switch is also coupled with the broadband network and enables each RF transmitting channel to be selectively coupled to any of the RF receiving channels. Phase correction pilot tones having a known phase relationship are generated at the telephone subscriber locations and transmitted in one or more phase correction pilot tone channels separate from the RF transmitting channels to the central switch. At the switch, the phase correction pilot tones are recovered and the phases of the pilot tones are used to correct the phases of the transmitting channels.
摘要:
A transmultiplexer is connected between digital facilities and analog facilities for translating information between TDM and FDM formats on the digital and analog facilities, respectively. Information in the TDM format is representative of a plurality of digital telephone signal channels and information in the FDM format is representative of a plurality of analog telephone signal channels. The total capacity of the digital facilities is smaller than the total capacity of the analog facilities. Any one of the digital channels can be selectively coupled to any one of the analog channels. The transmultiplexer is installed at a telephone central office facility as an interface between a cable telephony transmission system and a digital telephone switch. A host computer controls both the transmultiplexer and the digital telephone switch.
摘要:
A system for voice distribution amongst a plurality of telephone subscriber locations operating on a broadband cable network wherein RF transmitting and RF receiving channels for carrying voice and signalling information are established at the subscriber locations and coupled with the broad band network and a central switch is also coupled with the broadband network and enables each RF transmitting channel to be selectively coupled to any of the RF receiving channels.
摘要:
A system for voice distribution amongst a plurality of telephone subscriber locations operating on a broadband cable network wherein RF transmitting and RF receiving channels for carrying voice and signalling information are established at the subscriber locations and coupled with the broad band network and a central switch is also coupled with the broadband network and enables each RF transmitting channel to be selectively coupled to any of the RF receiving channels. The system is further providing with an adjusting means which is responsive to the traffic on the central switch and which enables the power level in each of the channels to be selectively adjusted.
摘要:
A power feed circuit provides power for a telephone subscriber loop connected to a unit of terminal equipment. The power feed circuit includes a first current supply circuit for supplying power to the subscriber loop when the unit of terminal equipment is in an on-hook condition and when the unit of terminal equipment is in an off-hook condition, and a second current supply circuit for supplying power to the subscriber loop only when the unit of terminal equipment is in the off-hook condition. Each current supply circuit includes a respective battery, transistor and bias network. The first current supply circuit is connected to the subscriber loop via a diode which is reverse-biased when the unit of terminal equipment is in the on-hook condition. The power feed circuit may be usefully applied in an Optical Network Unit (ONU) of a "fiber-in-the-loop" telephone system or in a Subscriber-Cable Interface Unit (SCIU) of a cable telephony system.
摘要:
An automatic telephone number identifier and method are provided wherein the seven digits of a telephone number developed in response to reentry of the number by a caller are validated by comparing the first three digits of the number to the NNX codes of the terminating central office of the trunk group carrying the call.