Data packet fragmentation in a cable modem system

• US 20060088056A1
• Filed: 12/02/2005
• Published: 04/27/2006
• Est. Priority Date: 10/30/1998
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Denney, Lisa V., Chen, Feng, Min, Jonathan S., Jones, Christopher R., Samueli, Henry, Nazareth, Sean F., Lu, Fang, Quigley, Thomas J.
• Granted Patent: US 7,519,082 B2
• Time in Patent Office: Days
• US Class Current: 370/468
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H
• CPC Class Codes: H04J 3/0655 using timestamps
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/203 Details of error rate determination, e.g. BER, FER or WER
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 25/03057 with a recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 41/142 using statistical or mathematical methods
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/1446 of transmission speed
• CPC Class Codes: H04W 72/542 : using measured or perceived quality
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A number of features for enhancing the performance of a cable transmission system, in which data is transmitted between a cable modem termination system at a headend and a plurality of cable modems located different distances from the headend, are presented. The power transmission level, slot timing, and equalization of the cable modems are set by a ranging process. Data is transmitted by the modems in fragmented form. Various measures are taken to make transmission from the cable modems robust. The upstream data transmission is controlled to permit multiple access from the cable modems.

Claims

1. A method for processing data packets to be transmitted by a cable modem on an upstream channel of a cable transmission system, the method comprising:

sending on the upstream channel a request for an amount of bandwidth to transmit a data packet;

receiving a grant of an amount of bandwidth and a transmission time period to transmit data in response to the request;

comparing the requested amount of bandwidth with the granted amount of bandwidth;

transmitting the entire data packet on the upstream channel during the transmission time period if the requested amount is less than or equal to the granted amount;

fragmenting the data packet into a plurality of portions if the requested amount is larger than the granted amount, one of the portions being less than or equal to the granted amount; and

transmitting the one portion that is less than or equal to the granted amount on the upstream channel during the transmission time period if the requested amount is larger than the granted amount.