International Business Machines Corporation

David William Davenport

Gary Scott Delp

Jeffrey Haskell Derby

Roger Lee Haskin

Marc Adam Kaplan

Israel Cidon

Kenneth Harvey Potter, Jr

Jeffrey James Lynch

Philip Lynn Leichty

Kevin Gerard Plotz

Inder Sarat Gopal

Shay Kutten

James P Janniello

Frank L Stein

John G Dudley

James W Eldridge

Henry Dexter Chadwick

Leung Ping Lee

Leonard DeGollado

Francis R Koperda

Gregory Allen Poist

Michael Joseph Flynn

Jeffrey Lloyd Weiner

A fault tolerant multimedia program distribution system includes a number of controllers for transmitting instances of predetermined multimedia program information to a communications network at predetermined times, a storage system for storing the multimedia program information, and a multiple access storage control device which allows multiple access to the storage system by more than one distribution controller at any time.

Apparatus for fault-tolerant multimedia program distribution

Method and apparatus are provided for segmenting a multiple program multimedia digital data stream for transmission over a distribution communications network. Each program multimedia digital data stream includes sequential transport system (TS) packets with program clock references (PCRs) at a set time interval and a program identification (PID) associated with the PCRs. The multiple program multimedia digital data stream is received. The TS packets are decoded to identify the program clock references (PCRs). A selected number N of TS packets are identified. The multimedia digital data stream into frames responsive to both the identified number N of TS packets and the identified PCRs. A program identification (PID) associated with one of the PCRs is selected for timing the transmission of segmented multiple program multimedia digital data stream. A time interval following an identified PCR associated with the selected program identification PID is identified and compared with the set time interval between the program clock references (PCRs). Responsive to the identified time interval being greater than the set time interval, a new program identification (PID) is selected for timing the transmission of segmented multiple program multimedia digital data stream.

Apparatus and method for segmentation and time synchronization of the

A packet communications system provides for point-to-point packet routing and multicast packet routing to limited subsets of nodes in the network, using a routing field in the packet header which is processed according to two different protocols. A third protocol is provided in which a packet can be multicast to the limited subset even when launched from a node which is not a member of the subset. The routing field includes a first portion which contains the route labels necessary to deliver the packet to the multicast subset. A second portion of the routing field contains the multicast subset identifier which can then be used to deliver the packet to all of the members of the multicast subset. Provision is made to backtrack deliver the packet to the last node identified before the multicast subset if that last node is itself a member of the subset.

Methods and apparatus for routing packets in packet transmission networks

This invention discloses a structure whereby a fixed frequency machine clocking signal can be multiplied in frequency by any desired integral value. The device uses a tapped delay line having a total time delay slightly less than the time of one-half cycle of the clocking signal and an exclusive-OR tree connected to the taps of the delay line to generate a higher frequency output clock signal. By interposing a known frequency division network to the input of the delay line, the output clock signal can be generated with any desired rational relationship to the driving clocking signal.

Clock converter circuit

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Raleigh, NC, United States of America

David William Davenport