Cirrus Logic Inc.

Peak Audio, Inc.

Gerrit E Rosenboom

Charles William Anderson

Kevin Paul Gross

William W Lowe

Derek W Lieb

In a ring topology digital network propagation delay is reduced A master node transmits a clock signal into the network in one direction. Each slave node propagates the signal to the next slave node without regeneration until the signal is received by the master node. The amount of time the signal takes to travel around the ring, is measured and is the total ring propagation delay. The master node then transmits a clock signal in both directions to the first slave node which measures the difference in their arrival times and transmits the difference to the master node. The process is repeated for each other slave node. Based upon each difference the master node computes the propagation delay for each ring segment. The master node transmits to each slave node the corresponding ring segment propagation delay and each slave node adjusts the phase of the node's clock.

Bandwidth optimization of ring topology through propagation delay compensation

Media access control for isochronous data packets in carrier sensing multiple access systems

The present invention has solved the collision problems in a CSMA network protocol and at the same time optimized performance of the network. This is accomplished by giving control of the size of the reserved portion and the size of the reservation portion of the communication frame to stations in the network. Further, the reserved portion is allotted to isochronous data packets each of whose length is variable. Also, only those packets that have a reservation are in the frame, and they are placed in the frame in order in accordance with there position of the permission or reservation list. The network timing is controlled by one of the stations acting as a conductor for the network. This conductor station receives the reservation requests from the other stations and builds a beat packet. The beat packet is transmitted from the conductor station to all stations of the network, and provides the timing or beat of the network that all stations are synchronized with. In addition, the beat packet contains the permission list (reservation list) identifying the stations that will transmit, and the order they will transmit during the frame. The network interrupt handler (46) and the conductor (56) at the conductor station build this beat packet.

Media access control for isochronous data packets in carrier sensing

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Lafayette, CO, United States of America

Gerrit E Rosenboom