Abstract: A system and method to provide voice enhancement circuits on a voice path on an individual basis, without having in-line circuits inserted into the lines or trunks. The enhancement circuit is inserted within one or more of the switches. This system comprises a switching system having a switching fabric and a central control, wherein the switching fabric includes several extended time slot interchange (XTSI) units connected to a time multiplex switch. The extended time slot interchange unit has approximately twice the capacity of a standard time slot interchange unit. Such XTSI is connected to voice enhancing circuits, which the TSI may then switch enhancement circuits into a call path. A method of setting up a call according to this invention includes routing the call to a switch, routing the call in the switch into an XTSI, which routes a call through the enhancement circuit, and then back through the XTSI.

Abstract: Method and apparatus are disclosed for establishing a wideband communication facility from a plurality of narrow bandwidth channels through a switched communications network from a first to a second terminal in response to a call from the first terminal indicating a customer-selected bandwidth for the wideband facility. Apparatus is also disclosed for establishing a wideband communication path through an illustrative switching system interconnecting groups of narrowband time division multiplexed channels established for the wideband facility. The path has a bandwidth greater than any of the TDM channels. Additional buffer memories and memory control arrangements are added to the initial and final stages of a time-space-time switching network to prevent any of the time slot data of a given time frame from being delayed and included in another time frame.

Abstract: A wideband communication facility is established via a switched network between calling and called terminals. The wideband facility comprises a number of segments, each segment including a plurality of narrowband time division multiplex channels having a total bandwidth at least equal to the bandwidth of the wideband facility. A switching system of the network interconnects the wideband facility segments and assembles all the data received in a given time frame from one segment into the single time frame for transmission to another facility segment. Additional buffer memories are added to the initial and final stages of a time-space-time switching network to insure that all the data received in one time frame from a given facility segment is assembled only into the same time farme for transmission on an outgoing facility segment.

Abstract: A phase locked loop circuit (100) for generating a periodic clock signal from a controlled oscillator circuit (130) in phase coincidence with a synchronous aperiodic data input signal is disclosed. A pulse of the data signal and a corresponding pulse of the clock signal are applied to a bistable circuit (FF1) having an output signal indicating which of the pulses occurs first in time. The pulses are further applied through delay circuitry (DLY1, DLY2) to another bistable circuit (FF2) having an output signal indicative of the magnitude of phase difference between the pulses. The output signals of the bistable circuits (FF1, FF2) are applied to a multilevel driver circuit (140) which generates an error correction signal pulse defining magnitude and direction of a correction signal to be applied to the oscillator circuit (130).