Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10298348-B2
Publication Date
2019-05-21
Expiration Date
Abstract
A cross connect apparatus or system with transparent clocking, consistent with embodiments described herein, connects a selected source or ingress port to a selected destination or egress port and clocks data out of the selected egress port using a synthesized clock that is adjusted to match a recovered clock from the selected ingress port. A transparent clocking system may generate the synthesized clock signal with adjustments in response to a parts per million (PPM) rate detected for the associated recovered clock signal provided by the selected ingress port. The cross connect system with transparent clocking may be a 400 G cross connect system with 10 G resolution. The cross connect system with transparent clocking may be used in optical transport network (OTN) applications, for example, to provide an aggregator and/or an add-drop multiplexer (ADM) or to provide a reconfigurable optical add-drop multiplexer (ROADM) upgrade to a higher data rate.
Core Innovation
The invention relates to a transparent clocking system for a cross connect apparatus that connects selected source ports to selected destination ports. The apparatus uses a plurality of multiplexers to selectively pass data signals from a selected source port to a selected destination port, while the transparent clocking system generates synthesized clock signals adjusted to match recovered clock signals for selected ones of the source ports. The system clocks data from selected ones of the destination ports without multiplexing the recovered clock signals.
In one apparatus configuration, each source port receives data signals and recovers clock signals from the data signals and clocks recovered data into an ingress FIFO module. Each destination port clocks data out of an egress FIFO module, and a local oscillator running faster than the recovered clock signals is used for clocking data into the egress FIFO module. Parts per million (PPM) detectors detect PPM rates of selected recovered clock signals, gapped clock enable logic adjusts a write clock of the egress FIFO module in response to a data rate of a corresponding selected recovered clock signal, and a clock generator generates a synthesized clock signal for the destination port in response to the detected PPM rate of the selected recovered clock signal.
The transparent clocking system further includes control logic implemented as a processor or finite state machine coupled to the PPM detectors module, the multiplexer, and the clock generator. The control logic controls selection of the source ports via the multiplexer and receives PPM rates and passes the PPM rate of the corresponding selected recovered clock signal to the clock generator. In additional system forms, the transparent clocking system is applied within an ODUk cross connect apparatus having OTU express ports and OTU add-drop ports, and within an optical services transport platform coupled to a ROADM and a router.
Claims Coverage
The independent claims describe apparatus and system architectures that combine selective multiplexing of data paths with a transparent clocking system that generates synthesized clocks matched to recovered clocks while avoiding multiplexing the recovered clock signals. Across the independent claims, the inventive content is organized into 4 main inventive feature sets.
Transparent clocking system for selected source-to-destination connections without multiplexing recovered clock signals
An apparatus with a plurality of source ports that receive data signals and recover clock signals, a plurality of destination ports that transmit data signals, and multiplexers configured to selectively pass data signals from a selected source port to a selected destination port, where a transparent clocking system generates synthesized clock signals adjusted to match recovered clock signals for selected ones of the source ports and clocks data from selected ones of the destination ports without multiplexing the recovered clock signals.
Transparent clocking with local oscillator, PPM detectors, gapped clock enable logic, and synthesized clock generation
An apparatus that multiplexes data paths from multiple source ports to a destination port via a multiplexer, where each source port clocks recovered data into an ingress FIFO module; a local oscillator running faster than the recovered clock signals clocks data into an egress FIFO module; PPM detectors detect PPM rates of selected recovered clock signals; gapped clock enable logic adjusts a write clock of the egress FIFO module in response to a data rate of a corresponding selected recovered clock signal; and a clock generator generates a synthesized clock signal for the destination port in response to the detected PPM rate of the selected recovered clock signal under control logic implemented as a processor or finite state machine.
ODUk cross connect apparatus integration with transparent clocking and muxponder/transponder
A system including at least one ODUk cross connect apparatus having plurality of OTU express ports and plurality of OTU add-drop ports, multiplexers configured to selectively pass data signals from any one of the ingress ports to any one of the egress ports, and a transparent clocking system configured to generate synthesized clock signals adjusted to match recovered clock signals for selected ones of the ingress ports and clock data from selected ones of the egress ports without multiplexing the recovered clock signals, with at least a first muxponder coupled to at least a first group of the express ports and at least one transponder coupled to at least one of the add-drop ports.
Optical services transport platform with ROADM/router and optical cross connect with transparent clocking
A system including an optical services transport platform configured to be coupled to a reconfigurable optical add-drop multiplexer and configured to be coupled to a router, and an optical cross connect apparatus with a plurality of ingress ports, a plurality of egress ports, multiplexers between ingress ports and egress ports configured to selectively pass data signals from any one of the ingress ports to any one of the egress ports, and a transparent clocking system configured to generate synthesized clock signals adjusted to match recovered clock signals for selected ones of the ingress ports and clock data from selected ones of the egress ports without multiplexing the recovered clock signals.
Across the independent claims, the document covers apparatus and system configurations in which data-path selection is performed via multiplexers while synthesized clock signals are generated to match recovered clock signals for selected connections. A core constraint in all independent claim sets is that the transparent clocking system clocks the selected egress data without multiplexing the recovered clock signals.
Stated Advantages
Clocks data from selected destination/egress ports without multiplexing the recovered clock signals.
Documented Applications
OTN applications using an ODUk cross connect apparatus including OTU express ports and OTU add-drop ports, including aggregator/ADM and ROADM upgrades via an OSTP and OXC.
OTN-style cross connect use cases including an optical services transport platform coupled to a ROADM and configured to be coupled to a router.
Interested in licensing this patent?