Tellabs Operations, Inc.

Lawrence D Weizeorick

Mark E Boduch

Chris R Zettinger

Mark A Richmond

David George Rancich

Bruce R Zelle

Steven T DeLong

Thayl Zohner

Sean M Furuness

Steve J Butz

Keith M Ellens

The specification discloses methods and apparatus for selecting the better of two or more copies of a cell in a cell-oriented redundant switching system connected to an external communications network. In the preferred embodiment, the best cell copy selection aligns redundantly transmitted cell streams before selecting cells for insertion in the data stream. Because the streams are aligned before the selection is made, the best cell copy selector compares each cell at the same instant in time, rather than basing its selection on past events.

Methods and apparatus for selecting the better cell from redundant streams within a cell-oriented environment

Clock recovery is used in a variety of communications network applications to enable nodes using different clocks to operate in an effectively synchronized manner. Example embodiments of the present invention include an apparatus and corresponding method for supporting client data transport with timing transparency and require neither a common clock to be available at both the ingress and egress sides of the connection nor overhead bytes to recover a client clock. Rather, client traffic clock recovery may be performed in example embodiments of the present invention entirely in the egress data path using the client data received from the ingress side after removing the clients signal from a higher level carrier signal.

Method and apparatus for supporting client data transport with timing transparency

A communication system includes a first ingress content processor that receives information associated with a first traffic type. The first ingress content processor places the information associated with the first traffic type into a system cell having a common system cell format. A second ingress content processor receives information associated with a second traffic type. The second ingress content processor places the information associated with the second traffic type into a system cell having the common system cell format. A switch fabric receives system cells from the first and second ingress content processors. System cells from the first ingress content processor are automatically sent to the switch fabric while system cells from the second ingress content processor are required to be scheduled before being sent to the switch fabric. The switch fabric separately queues system cells carrying payloads associated with the first traffic type from system cells carrying payloads associated with the second traffic type. The switch fabric services system cells carrying payloads associated with the first traffic type prior to servicing system cells carrying payloads associated with the second traffic type.

System and method for communicating data using a common switch fabric

Systems and methods are disclosed for detecting framing data in a telecommunications signal. In one embodiment, a frame synchronizer circuit is provided that includes an interface for receiving bits of a telecommunications signal and storage for storing a framing state for the bit positions in the frame, the framing state for a given bit position indicating whether that bit position is a potential holder of the frame synchronization pattern. The frame synchronizer circuit also contains a state update function that determines the current-state for each bit position based on the bit position's previous state, and the value of the most recently received bit in that bit position. The encoding scheme makes use of shorter bit length symbols to represent statistically more frequently occurring states. In one embodiment, a single code word is used to record the state of a sequence of consecutively occurring bit positions that share the same state.

Systems and methods for frame synchronization

A multiprocessing apparatus includes a memory and a plurality (M) of processors coupled to share the memory. Access to the memory is time-division multiplexed among the plurality of processors. In one embodiment, a selected processor retrieves M words of instruction forming K instructions during a given clock cycle. The selected processor executes M&#x2212;K NOP instructions if K&#x3c;M.

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Lisle, IL, United States of America

Lawrence D Weizeorick