Ciena

About: Ciena is a company organization based out in Hanover, Maryland, United States. It is known for research contribution in the topics: Signal & Node (networking). The organization has 1259 authors who have published 1557 publications receiving 25989 citations.

Network device including reverse orientated modules

Abstract: The present invention provides a network device with multiple modules or printed circuit boards where certain of the modules are reverse orientated with respect to the other modules. Reverse orientating certain modules better utilizes routing resources and enables a high switching capacity network device, including both physical layer switch/router subsystems and upper layer switch/router subsystems, to be fit in one telco rack. Providing a multi-layer network device in one telco rack allows for intelligent layer 1 switching (for example, dynamic network connection set up), allows for one network management system to control both layer 1 and upper layer networks and eliminates grooming fees. Compared with separate layer 1 and upper layer network devices or a multi-layer network device occupying multiple telco racks, a single network device saves valuable telco site space and reduces expenses by sharing overhead such as the chassis, power and cooling.

System, device, and method for supporting cut-through paths in an optical communication system

Abstract: A system, device, and method for supporting cut-through pats in an optical communication system involves obtaining hop count and quality of service information by an initiating device and using the hop count and quality of service information by the initiating device to make decisions relating to a cut-through path. The hop count and quality of service information is provided in a reply message that is sent by a terminating device and modified by intermediate devices between the initiating device and the terminating device. The terminating device sends the reply with a hop count equal to one and quality of service information for a first link (hop) toward the initiating device. Each intermediate device increments the hop count in the reply and adds quality of service information for a next link (hop) into the reply.

Method for power reduction in inter-symbol interference limited channels

Abstract: Method of reducing transmission power across a loop in a discrete multitone communication system A first signal to noise ratio (SNR) is estimated for a signal transmitted across the loop A second SNR is estimated for a signal across the loop, the second SNR signal being estimated exclusive of a predetermined portion of the first SNR A power cutback scaling factor is determined in accordance with the first SNR, the second SNR, and a predefined maximum SNR degradation amount The transmission power is scaled in accordance with said scaling factor for reducing said transmission power In such a manner, fine gains are computed such that the transmit power is reduced without significantly affecting the achieved data rate

Opportunity based path computation systems and methods in constraint-based routing

Abstract: A method, a controller, and a network include determining an opportunity cost metric for each of a plurality of links in a network including a plurality of nodes, wherein the opportunity cost metric comprises a future constraint reflecting expectations for growth on currently established connections on each link of the plurality of links; receiving a request for a new connection between two nodes of the plurality of nodes in the network; and utilizing a constraint-based routing algorithm to determine a path for the new connection between the two nodes, wherein the constraint-based routing algorithm determines the path through the plurality of nodes via the plurality of links based on a plurality of constraints including the opportunity cost metric.

Systems and methods for real-time compensation for non-linearity in optical sources for analog signal transmission

Abstract: The present invention provides a compact analog directly modulated laser configuration that is suitable for use in the field that uses electrical feedback to compensate for non-linearity in real time, such that no matter how the LI curve changes, the electrical feedback compensates for non-linearity by amplifying a portion of the output analog optical signal and combining it with the input analog electrical signal using the standard control method of negative feedback. When the gain of the feedback loop is relatively high, the overall transfer function of the system is primarily dependent on the feedback loop gain block, which is substantially linear. This is accomplished by incorporating a relatively large bandwidth photo-detector at the back facet of the laser that both monitors the output power of the system and provides a feedback signal to the linearization control circuit, as well as an amplifier. The amplified signal from the relatively large bandwidth photo-detector is used to correct for various undesirable effects, such as non-linearity and relative intensity noise (RIN) of the laser. The signal from the relatively large bandwidth photo-detector also allows the laser to operate effectively close to threshold.