Multiplex communications – Wide area network – Packet switching
Patent
1990-10-31
1992-10-20
Olms, Douglas W.
Multiplex communications
Wide area network
Packet switching
370 942, 370102, H04J 322
Patent
active
051576554
ABSTRACT:
An apparatus which receives a gapped data component of an STS-1 signal and provides therefrom an ungapped DS-3 data signal is provided and includes a FIFO for receiving the data component of the STS-1 signal, a measuring circuit having an input clock related to the STS-1 signal and the output clock of the apparatus as inputs for effectively measuring the relative fullness of the FIFO, and a voltage controlled crystal oscillator (VCXO) for receiving a control signal from the measuring circuit and for generating the output clock of the apparatus in response thereto, where data in the FIFO is taken out of the FIFO as the DS-3 signal according to the rate of the output clock. The FIFO is preferably a byte wide RAM, and the measuring circuit is comprised of two counters, an XOR gate, and a low pass filter. One counter receives the apparatus output clock as its input, while the other counter receives a gapped STS-1 data payload input clock as its input. The msb's of the counters are compared by the XOR gate, and the duty cycle of the XOR gate output provides an indication of the difference between the rates of the input and output clocks. The low pass filter filters out high frequency changes in the duty cycle due to the gaps in the input clock, and provides the VCXO with a dc signal which changes with the long term average of the duty cycle. In response to this dc signal, the VCXO changes the output clock rate. By feeding back the output clock to one of the counters of the measuring circuit, a closed loop system is established.
REFERENCES:
patent: 4053715 (1977-10-01), Drapkin
patent: 4159535 (1979-06-01), Fuheman
patent: 4513427 (1985-04-01), Borriello et al.
patent: 4551830 (1985-11-01), Huffman
patent: 4667324 (1987-05-01), Graves
patent: 4674088 (1987-06-01), Grover
patent: 4685101 (1987-08-01), Segal et al.
patent: 4833673 (1989-05-01), Chao et al.
patent: 5033064 (1991-07-01), Upp
patent: 5052025 (1991-09-01), Duff et al.
Hamlin, Jr. Robert W.
Upp Daniel C.
Chin Wellington
Gordon David P.
Olms Douglas W.
TranSwitch Corp.
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