Abstract: According to one embodiment, a method is disclosed. The method comprises receiving a first set of clock signals from a first clock unit at a second clock unit whenever the first clock unit is operating. The method further includes receiving a signal indicating that the second clock unit is to enter into the operating mode; and entering a holdover mode at a protection timing unit within the second clock unit. In the holdover mode, the protection timing unit generates output clock signals based upon the first set of clock signals received from the first clock unit at the second clock unit.

Abstract: A method for routing network switching information includes generating at one Time Slot Network (TS Net) data firame from at least one data frame of a first type. The TS Net data frame comprises switching event information. The TS Net data frame is transferred and stored among a number of network elements using a backplane network. Compare operations are performed among prespecified data frames of the TS Net data frame, and at least one interrupt signal is generated in response to detected changes resulting from the compare operations. Information routing is controlled in at least one network and the associated network elements in response to the interrupt signals.

Abstract: An interface for communications among network elements of at least one network is provided, comprising at least one transmitter, at least one receiver, at least one processor, and at least one backplane coupled among the network elements. Data frames of a second type, or Time Slot Network (TS Net) data frames, are generated and transferred over the backplane in response to receipt data frames of a first type from the network. The TS Net data frames comprise switching event information. Compare operations are performed among prespecified TS Net data frames at prespecified intervals, and at least one interrupt signal is generated in response to data changes determined by the compare operations. Information routing is controlled over the network by a processor in response to the interrupt signal.

Abstract: A system for use with a subscriber line carrier such as a SLC-5 or other SLC type system. In accordance with a specific embodiment, the system provides a multiplex channel unit 25 that inputs T1 line signals, and outputs multiple telephone line signals in a format such as 2B1Q or 4B3T over a twisted pair 13 to an RT 35. The RT 35 converts the full duplex multiplexed signals to analog service for a subscriber 12.

Abstract: A method and related apparatus for concurrent transmission and reception of at least one analog voice telephone signal and at least one ISDN service signal between a first location and a second location over a single twisted pair using a digitally encoded signal that is selected from the group consisting of 2B1Q and 4B3T signals. The method further includes the steps of sending line power over the single twisted pair, transferring the digitally encoded signal to the second location over the single twisted pair, and detecting non-operation of the digitally encoded signal between the first location and the second location to thereby impose a bypass lifeline and provide the analog telephone signal at the second location over the single twisted pair. The method also includes the step of providing the ISDN signal and the analog telephone signal at the second location over the single twisted pair when the non-operation is not detected.

Abstract: A method and apparatus for converting an analog voice channel signal and a 4-wire digital signal into a single 2-wire digital signal which can be transferred over a single twisted pair line. In one aspect, the method comprises the steps of converting the analog voice channel signal into a first binary signal, converting the 4-wire digital signal into a second binary signal, combining the first binary signal and the second binary signal into a higher rate binary signal, and converting the higher rate binary signal into a 2-wire digital signal which can be transmitted to another location over a single twisted pair line. In another aspect, the method comprises the steps of converting a 2-wire digital signal to a higher rate binary signal, separating a first binary signal and a second binary signal from the higher rate binary signal and converting the first binary signal into an analog voice channel signal, and converting the second binary signal into a 4-wire digital signal.

Abstract: A method and apparatus for converting an analog voice channel signal and a 4-wire digital signal into a single 2-wire digital signal which can be transferred over a single twisted pair line. In one aspect, the method comprises the steps of converting the analog voice channel signal into a first binary signal, converting the 4-wire digital signal into a second binary signal, combining the first binary signal and the second binary signal into a higher rate binary signal, and converting the higher rate binary signal into a 2-wire digital signal which can be transmitted to another location over a single twisted pair line. In another aspect, the method comprises the steps of converting a 2-wire digital signal to a higher rate binary signal, separating a first binary signal and a second binary signal from the higher rate binary signal and converting the first binary signal into an analog voice channel signal, and converting the second binary signal into a 4-wire digital signal.

Abstract: A method and apparatus 200 for converting dual 4-wire digital data services (DDS-1 and DDS-2) for transmission over a single twisted pair telephone line 205. The present method includes use of a digital data service remote terminal 219 and a digital data service central office terminal 201. Each terminal converts more than one 4-wire digital data services into a 2B1Q signal for transmission over the single twisted pair telephone line 205. The present method provides an efficient and cost effective technique for increasing 4-wire digital data services to a customer premises without a corresponding increase in the number of telephone lines.

Abstract: A system for use with a subscriber line carrier such as a SLC-96. The system provides a multiplex channel unit 10 that inputs T1 line signals, and outputs multiple telephone line signals in a format such as 2B1Q over a twisted pair 13 to an RT 35. The RT 35 converts the full duplex multiplexed signals to analog service for a subscriber 12.

Abstract: An improved method and apparatus for transmission of dual 4-wire analog data services between a telephone company location and a subscriber premises over a single twisted pair, providing a 4:1 pair gain. In a preferred embodiment the invention provides for method and apparatus for transmission of multiple analog data signals for dual 4-wire analog data services over a single twisted pair from telephone company equipment to a subscriber, using 2B1Q or 4B3T digital signals.

Abstract: A method and apparatus 200 for converting dual 4-wire digital data services (DDS-1 and DDS-2) for transmission over a single twisted pair telephone line 205. The present method includes use of a digital data service remote terminal 219 and a digital data service central office terminal 201. Each terminal converts more than one 4-wire digital data services into a 2B1Q signal for transmission over the single twisted pair telephone line 205. The present method provides an efficient and cost effective technique for increasing 4-wire digital data services to a customer premises without a corresponding increase in the number of telephone lines.

Abstract: A method and apparatus 200 for transferring analog voice telephone signals and digital data service signals simultaneously from a telephone company location to a customer premises over a single twisted pair telephone line 205. The present apparatus 200 includes an easily installed voice plus digital data service remote terminal 203 and voice plus digital data service central office terminal 201. The present apparatus can provide a 3-to-1 pair gain by multiplexing signals representing the analog voice telephone signals and 4-wire digital data service signals.