Luminous Networks, Inc.

Samsung Electronics Co., Ltd.

Charles Barry

Jason C Fan

Vinay K Bannai

Robert F Kalman

Prasad Prabhakar Jogalekar

Inwhan Choi

Robert Stillman

Sohail Mallick

Warren Watts

Seshadri Srinivasan

Atul Shinde

Richard Lindquist

Benson Chuong

David Watson

A method and structure for the distribution and utilization of synchronization within an asynchronous network is described herein. Synchronization is distributed through an asynchronous network via a synchronization symbol periodically inserted on the MAC layer. The priority of this symbol ensures that this symbol is inserted in the MAC layer data stream ahead of all other types of symbols. The insertion of the synchronization symbol in the middle of an ongoing data frame is supported. In addition, a method for synchronization symbol distribution throughout an asynchronous network is presented, along with a method for switching to a new synchronization path (in the event of loss of original synchronization path) based on minimum number of hops from the synchronization source. In addition, a method is described for utilization of the count and interval of received synchronization symbols and the count and interval of transmitted synchronization symbols to generate an error correction signal used in the process of frequency locking of a device's internal hardware to received synchronization symbols from another device. Using the prioritized insertion capability required for synchronization symbols, a variety of other MAC layer control symbols are defined to perform other functions, such as propagation time measurement between adjacent nodes.

Synchronization of asynchronous networks using media access control (MAC) layer synchronization symbols

The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes flows on the ring that would provide the minimum number of hops to the destination node. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault. Since the available links will now see more data traffic due to the failed link, traffic designated as 'unprotected' traffic is given lower priority and may be dropped or delayed in favor of the 'protected' traffic. Specific techniques are described for identifying a failed link, communicating the failed link to the other nodes, differentiating between protected and unprotected classes of traffic, and updating the routing tables.

Dynamically allocated ring protection and restoration technique

The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes flows on the ring that would provide the minimum number of hops to the destination node. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault. Since the available links will now see more data traffic due to the failed link, traffic designated as &ldquo;unprotected&rdquo; traffic is given lower priority and may be dropped or delayed in favor of the &ldquo;protected&rdquo; traffic. Specific techniques are described for identifying a failed link, communicating the failed link to the other nodes, differentiating between protected and unprotected classes of traffic, and updating the routing tables.

Selecting a routing direction in a communications network using a cost metric

An architecture for transport of multiple services in connectionless packet-based networks is described herein, along with the packet format used for data transport in this architecture. The architecture supports transport of both connectionless packetized data and framed data from synchronous leased lines. The architecture supports transparent packetization of incoming DS1 data. The architecture works for mesh architectures but is optimized for OSI Layer (crossconnect) and Layer (Virtual LAN, or VLAN) services and for ring topologies, since for these services in a ring no path setup is required using a label distribution protocol. In addition, it simultaneously supports OSI Layer , Layer , and Layer services.

Architecture for transport of multiple services in connectionless packet-based communication networks

A method and apparatus for adjusting the position of an antenna to improve reception at a television includes a signal generator which measures the signal strength received by the antenna. The signal generator sends a low frequency coded signal to a display visible to a person who is adjusting the antenna. The display provides a quantitative indication of the signal strength to the installer of the antenna, allowing precise adjustments to be made in accordance with the displayed value. The signal generator provides the coded signal to the display via the same cable used to carry the received signals from the antenna to a receiver, such as a set-top box.

Satellite dish positioning system

Growing community of inventors

Campbell, CA, United States of America

Charles Barry