Nortel Networks Corporation

Northern Telecom Limited

Ciena Corporation

Rockstar Consortium US LP

Lg-erricsson Co., Ltd.

Rockstar Bidco, LP

Rpx Clearinghouse LLC

Lg-ericsson Co., Ltd.

Wang-hsin Peng

Wang-Hsin Peng

Donald Russell Ellis

Kim Bryon Roberts

Eric Maniloff

David Wright Martin

David John Nicholson

Mark Temple Cobbold

Larry Babineau

Peter Arnold Giese

David MacDonald Delaney

Peter Martin Kenneth Cottreau

Alan Hurren

Jonathan Davey

Dino Cosimo DiPerna

Yang Sup Lee

Joanne Wilde

Richard Deslandes

John B Mills

Peter Martin Cottreau

David Macdonald Delaney

Eric S Maniloff

The present disclosure relates to systems and methods for fast digital signal processor (DSP) optical receiver recovery, namely for optical modems configured on a client side. This approach can be used in optical protection switching (OPS) applications to allow switching between two client links fast, i.e., within 50 ms. A receiver (Rx) digital signal processor (DSP) in an optical receiver includes circuitry configured to detect traffic is interrupted on a current link, enter a holdoff period, and one of i) receive good traffic during the holdoff period and ii) have the holdoff period expire that causes a notification to a host device and retrain to acquire an optical signal.

Fast optical receiver recovery on client side using optical interconnects with DSPs

A method and apparatus for adjusting a symbol decision threshold at a receiver in a communication network enables the receiver to be adapted to more correctly receive symbols as transmitted by a transmitter. In one embodiment, a received bit imbalance is detected by a receiver prior to error correction and after error correction to determine whether an error component of the received signal contains larger numbers of ones or larger numbers of zeros. Where the transmitter scrambles the signal prior to transmission, the receiver will also scramble the signal after error correction and prior to counting the number of zeros or ones. Any imbalance between the number of transmitted and received ones or zeros is used as feedback to adjust threshold values used by detectors to fine tune the manner in which the receiver interprets incoming signals.

Method and apparatus for adjusting a symbol decision threshold at a receiver in a communication network

Provided is a method and apparatus for segmenting packets into cells of variable sizes in order to facilitate the parallel transport of data symbols common to a single packet through a composite medium made up of a number of lanes. According to the invention the method of segmenting packets results in cell sizes that efficiently use the available capacity and minimize the complexity of any additional apparatus required in the receivers used to reassemble the packets from the variable-sized cells. Additionally, the invention could be advantageously combined with the Generic Framing Procedure (GFP) as defined in ITU-T G.7041/Y.1303 that was ratified December 2001.

Physical capacity aggregation system and method

A system and method for clock synchronization in a network having one or more asynchronous data links is provided. A clock signal is propagated through, at the physical layer, a sequence of network devices linking a source network device to a destination network device of the network. Each asynchronous data link between the source network device and the destination network device is adapted to receive an incoming clock signal from the previous network device and then provide a clock signal synchronized to the received clock signal to the next network device of the sequence. At the same time, each network device of an asynchronous segment of the network can continue to transmit packets of data asynchronously. By locking the link-based frequency on a per link bases, the receiver clocks located at the edge of a network can be tied directly to a primary source located in the core network.

Method and system for link-based clock synchronization in asynchronous networks

A method and apparatus for minimizing starvation of a station in a ring networked environment includes allocating a tax to each of the stations in the ring, and, for each packet that is to be transited though the ring, providing bandwidth to the station in the form of a tax packet, which allows the station to have ring access.

Source credit based fairness scheme

A control system enables transport of payload data across a dual counter rotating ring (DCRR) network having two or more nodes, each node providing access to the DCRR network by a respective local area network (LAN) subtending the node. The control system comprises a topology learning entity operative within each node for monitoring individual, links of the DCRR, discovering the active topology of the DCRR, communicating topology changes to other nodes in the DCRR, and informing frame forwarding and learning processes of the topology to enable failover to redundant resource upon detection of a network component failure. A frame forwarding process selects a shortest path route between a source and a destination node in the DCRR, and forwards frames to the destination node via the selected shortest path route. An address learning process inspects a source medium access control (MAC) address in each received frame to learn a shortest path route for each MAC address.

Enhanced dual counter rotating ring network control system

A fairness scheme is disclosed for managing data flow between nodes in a bi-directional ring network. A method in accordance with the invention controls the output bandwidth of nodes in a bi-directional ring network by: identifying a congested span comprising a head node having a congested downstream link, and a plurality of chain nodes contributing to the congestion in the downstream link: adjusting the output bandwidth of the head node as a function of the congestion in the downstream link; and adjusting the output bandwidth of the chain nodes as a function of the congestion in the downstream link.

Method and apparatus for managing communications between nodes in a bi-directional ring network

A communications system is provided having SONET communications channels extending between first and second locations. The channels include pairs of forward and reverse channels for carrying traffic in normal operation between first and second locations and a protection channel for carrying traffic of one channel in the event of a fault. Each pair of forward and reverse channels is provided on a shelf at each location, the shelves having the same relative position at both locations and the protection channel is provided on a protection shelf. The protection channel includes, between the first and second locations, a forward optical link and a reverse optical link and at each of the first and second locations, a single protection loop, coupling the forward and reverse optical links, that forms the protection channel. The protection loop is used to provide, at each location, a local virtual protection loop for indicating the protection requirements and status of the respective location, and a remote virtual protection loop for indicating the protection requirements and status of the location remote from the respective location. The local protection loop is provided by inserting K1 and K2 bytes into E1 slots of STS-1 #25 and #2, respectively. The remote protection loop is provided by inserting K1 and K2 bytes into E1 slots of STS-1 #26 and #3, respectively.

Communications system with a single protection loop

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Ottawa, Canada

Wang-Hsin Peng