Patent References 3754098 Local area network control system synchronization with phase-lock loop Method and means for transferring a data payload from a first SONET signal to a SONET signal of different frequency Patent #: 5142529 InventorAssigneeApplicationNo. 054332 filed on 04/28/1993US Classes:370/412, Queuing arrangement370/466, Converting between protocols370/517, Including delay device375/371Phase displacement, slip or jitter correctionExaminersPrimary: Safourek, Benedict V.Assistant: Jung, Min Attorney, Agent or FirmInternational ClassH04J 003/06AbstractAn adaptive clock recovery arrangement for deriving a synchronous clock from an asynchronous, packet stream such as an asynchronous transfer mode (ATM) cell stream. The deviation in the magnitude of information stored in a first-in-first-out memory is continually monitored, and the synchronous clock frequency, referred to as the adaptive line clock frequency, is adjusted in a plurality of modes, under the control of a processor. The adjustment is made in response to a detected increasing condition of the monitored deviation. The adjustments are open-loop adjustments made without continually adjusting the adaptive line clock frequency based on the monitored deviation. Damping is substantially reduced compared with "conventional" PLL arrangements because the open-loop adjustments result in a rapid frequency correction with perfect or nearly perfect deadbeat damping, i.e. without the frequency oscillations that continue after the correct frequency is reached in closed-loop arrangements.Other References
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