General Instrument Corporation

Broadcom Corporation

Avago Technologies International Sales Pte. Limited

Victor T Hou

Jeyhan Karaoguz

Wael William Diab

Vinko Erceg

Charles Abraham

Mark Kent

Thomas J Kolze

Niki Roberta Pantelias

Lisa Voigt Denney

David Michael Pullen

John Daniel Horton

Steven E Anderson

A Scott Hollums

Sherman Chen

Jonathon A Fellows

Scott A Hollums

Niki Roberta Pantellas

Bandwidth is adaptively allocated in an upstream channel of a layered data communication network such as that used for carrying messages from a number of subscriber units (,) to a central controller (,), for example, to allow the subscriber units to send data for Internet access, videoconferencing, or voice communication. A running total of unallocated bandwidth (BWA(j)) is maintained in successive control intervals. A traffic count (C(i)) is determined for each subscriber unit by measuring the bandwidth which is used, for example, by counting the number of slots used in a control interval. The assigned bandwidth (B(i)) of the subscriber units is then adjusted when a ratio (K) of the traffic count to the assigned bandwidth is at or below a lower threshold (T,), and the running total of unallocated bandwidth is incremented by the decrease in the assigned bandwidth. The assigned bandwidth may be increased when a ratio (K) of the traffic count to the assigned bandwidth is at or above an upper threshold (T,) by distributing the unallocated bandwidth among the subscriber units. A subscriber unit hierarchy may be used to grant priority to selected users.

Dynamic bandwidth allocation for a communication network

Apparatus is provided for communicating data packets in variable length bursts over a physical layer in a multilayer data communication scheme. Each burst contains information data (,) and overhead (,). The overhead includes forward error control (FEC) data (,). Different burst modes (FIG.,) are provided to enable a trade-off to be made between bandwidth efficiency and data transmission robustness. The burst modes provide different combinations of modulation (such as QPSK and 16-QAM), symbol rates, FEC coding levels and frame and preamble structure. The apparatus is particularly suitable for use in upstream communications over hybrid fiber coax cable television plants.

Variable length burst transmission over the physical layer of a multilayer transmission format

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La Jolla, CA, United States of America

Victor T Hou