Agere Systems Inc.

Lsi Corporation

Michael Samuel Shaffer

Himanshu Mahendra Thaker

Charles Albert Webb, Iii

Lesley Jen-Yuan Wu

Lin Hua

Cheng Gang Duan

Qian Xu

Tao Wang

Ze Mian Huang

Mohammad Shafiul Mobin

Si Ruo Chen

Jay Patrick Wilshire

Sameer Gupta

Chenggang Duan

Harold J Wilson

Methods and apparatus are provided for framing synchronization control for a framer/mapper/multiplexor (FMM) device with 1+1 and equipment protection. FMM device are disclosed that synchronize one or more internal signals by changing a phase of the one or more internal signals without changing a frequency of the one or more internal signals based on a desired phase at a destination of each of the one or more internal signals. A programmable synchronization signal may optionally be employed for the synchronization.

Methods and apparatus for system framing synchronization control for a framer/mapper/multiplexor device with 1+1 and equipment protection

A communication device comprises a signal combiner, first storage elements, second storage elements and a controller. The signal combiner is configured to combine overhead information with additional information in forming a frame of a signal. The first storage elements are adapted to receive respective portions of a given block of the overhead information to be applied to the signal combiner, and the second storage elements are coupled between respective ones of the first storage elements and respective inputs of the signal combiner. The controller is operative to monitor a count of portions of the frame as the frame is formed by the signal combiner and to control loading of the portions of the given block of the overhead information into the second storage elements from the first storage elements responsive to the monitored count. The disclosed techniques for guaranteed consistent overhead insertion can be implemented in any type of communication system which utilizes overhead insertion in its framing operations.

Method and apparatus for signal formation with guaranteed consistent overhead insertion

Techniques are disclosed for in-band communication of alarm status information or other information between physical layer devices comprising a working device and a protection device in a network-based communication system. In one aspect, a protection receive signal is monitored in the protection device for the presence of alarm status information. The protection device encodes alarm status information extracted from the protection receive signal, and inserts the encoded alarm status information into one or more designated portions of a protection loop-back signal supplied from the protection device to the working device. The protection loop-back signal is monitored in the working device and the encoded alarm status information therein is decoded and utilized by the working device to initiate a protection switching operation.

In-band communication of alarm status information in a synchronous transport communication system

An apparatus for monitoring of received information in a communication device comprises a first buffer having a plurality of storage elements adapted to store respective portions of the received information, a second buffer coupled to the first buffer and having a plurality of storage elements corresponding to respective ones of the storage elements of the first buffer, and controller circuitry coupled to the buffers and operative to detect a message sequence comprising a plurality of the portions of the received information. The second buffer stores a previously-detected message sequence loaded from the first buffer into the second buffer under control of the controller circuitry. The controller circuitry in detecting a current message sequence is configurable in at least first and second different monitoring modes each associated with a different message format. The monitoring mode of the controller circuitry may be adaptively configured based at least in part on a detected message sequence.

Received information monitor adaptive to multiple monitoring modes in a communication device

Methods and apparatus are provided for evaluating the throughput limit of a communication system, such as a network node or system. A throughput limit of a communication system is evaluated by receiving a request to allocate at least one connection of a given data type; obtaining an assigned weight for the at least one connection, wherein the assigned weight is based on the throughput limit and a processing limit indicating a throughput of the communication system for the given data type within a given time window; and determining whether to allocate the at least one connection of a given data type based on whether a sum of the assigned weights for each existing allocated connection for each data type exceeds the throughput limit. The assigned weight for a given data type can be subtracted from the sum upon receiving a request to de-allocate a connection.

Methods and appratus for evaluating a utilization of a system that provides connections using a normalized bandwidth scheme

A communications system includes a physical layer device (PLD) and a logical link device (LLD), each having respective send and receive interfaces being substantially identical to define symmetrical interfaces for the system. Accordingly, design and manufacturing is simplified compared to conventional systems. In addition, advantages are also provided in terms of loopback capability and packaging options. The PLD comprises a PLD send interface including PLD parallel information outputs, and a PLD receive interface including PLD parallel information inputs. Similarly, the LLD comprises an LLD receive interface including LLD parallel information inputs, and an LLD send interface including LLD parallel information outputs. Parallel communications channels connect the PLD information outputs to respective LLD information inputs, and connect the LLD information outputs to respective PLD information inputs. The PLD send interface and the LLD send interface are substantially identical, and the PLD receive interface and the LLD receive interface are substantially identical to thereby define the symmetrical interfaces for the system. In view of the symmetrical interfaces, the PLD and the LLD may operate in a push-push configuration. Deskewing features are also provided.

Communications system with symmetrical interfaces and associated methods

In one embodiment, the present invention is a framer/mapper/multiplexor (FMM) device that can simultaneously (i) send protection copies of both its working incoming high-speed (e.g., STS-12) signal and incoming low-speed signals to a protection FMM device, and (ii) receive corresponding protection signals from the protection FMM device. Furthermore, the FMM device can select between working and protection signals at a switching level (e.g., STS-1) lower than the high-speed level, allowing for 1+1 APS/MSP protection and equipment protection at the board level, the device level, and at the STS-1 level. Yet further, four or more FMM devices can be configured so that all FMM devices can communicate with their corresponding protection FMM devices using a single, shared, 4-pin link (e.g., quad-OC-3 mode), and still select between working and protection signals at the switching level (e.g., STS-1).

Framer/mapper/multiplexor device with 1+1 and equipment protection

In a communication system comprising a mapper or other type of physical layer device coupled to a link layer device, the physical layer device comprises payload extraction circuitry and payload insertion circuitry. The payload extraction circuitry is configured to extract a payload from an ingress synchronous transport signal received over an ingress link, and the payload insertion circuitry is configured to insert a payload received from the link layer device into an egress synchronous transport signal for transmission over an egress link. The payload extracted from the ingress synchronous transport signal is transmitted by the physical layer device to the link layer device over an output serial data line of a serial interface, and the payload inserted into the egress synchronous transport signal is received by the physical layer device from the link layer device over an input serial data line of the serial interface.

Synchronous transport signal mapper with payload extraction and insertion functionality

Virtual concatenation circuitry is disclosed which provides stall need detection and an associated stall mechanism in a network element of a data communication network. The virtual concatenation circuitry in a preferred embodiment is operative to provide differential delay compensation for one or more member streams of a virtual concatenation stream. The differential delay compensation involves introducing delay into at least one of the member streams. The stall need detection aspect of the invention relates to detecting a condition under which introduction of the delay is required for alignment of member streams, for example, upon addition of a member stream to the virtual concatenation stream. Such a condition may arise, for example, if a transmission delay of an added stream is larger than that of all other member streams of the virtual concatenation stream. The stall implementation ensures that, during at least a portion of the introduced delay for a given member stream, data transmitted for that member stream is marked as invalid, thereby preventing the introduction of data errors.

Stall need detection and associated stall mechanism for delay compensation in virtual concatenation applications

A communications system comprises a physical layer device (PLD) including a PLD send interface which, in turn, includes PLD parallel information outputs and at least one PLD control output. The system also includes a logical link device (LLD) which comprises an LLD receive interface which, in turn, includes LLD parallel information inputs and at least one LLD control input. First parallel communications channels connect the PLD information outputs to respective LLD information inputs, and at least one second communications channel connects the at least one PLD control output to the at least one LLD control input so that control signals are sent from the PLD to the LLD out-of-band from information signals. Accordingly, control speed is enhanced, and information throughput efficiency is not compromised. The PLD may further include a PLD receive interface including PLD parallel information inputs and at least one PLD control input, and the LLD may further comprise an LLD send interface including LLD parallel information outputs and at least one LLD control output. In accordance with this aspect of the invention, the PLD and LLD are operable in a push-push configuration. Another advantageous feature of the invention is that the interfaces may be symmetric.

Communications system and associated methods with out-of-band control

A communications system includes first and second devices connected by parallel communications channels. The first device preferably comprises a string-based framing coder for determining and appending a string-based framing code to each information symbol string of information symbol strings to be transmitted in parallel over respective parallel communications channels. Each string-based framing code is preferably based upon at least some of the information symbols in the respective information symbol string. In addition, the second device preferably includes a deskewer for aligning received parallel information symbol strings based upon the string-based framing codes. In other words, the string-based framing codes and their use to align received information symbol strings permit the information symbol to be transmitted at high rates and over relatively long distances and thereby be subject skew. The information symbols may be binary bits. The string-based coder may comprise a cyclic redundancy checking (CRC) coder for determining and appending CRC codes to respective information bit strings. Thus, the deskewer may comprise a CRC framer for framing the information bit strings based upon the CRC codes.

Communications system and associated deskewing methods

A communications system includes a first device comprising a plurality of electrical-to-transmission medium converters, and a second device comprising a plurality of transmission medium-to-electrical converters to be connected to respective ones of the electrical-to-transmission medium converters via at least one transmission medium and defining parallel communications channels between the first and second devices, and wherein deskewing is provided. More particularly, the first device may include a string-based framing coder for determining and appending a string-based framing code to each information symbol string of information symbol strings to be transmitted in parallel over respective parallel communications channels. Each string-based framing code is based upon at least some of the information symbols in the respective information symbol string. The second device preferably comprises a deskewer for aligning received information symbol strings based upon the string-based framing codes. The symbols may be binary bits, and the string-based codes may be CRC codes.

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Lynnfield, MA, United States of America

Michael Samuel Shaffer