Method and apparatus for converting between byte lengths and burdened burst lengths in a high speed cable modem

• US 20030196207A1
• Filed: 05/27/2003
• Published: 10/16/2003
• Est. Priority Date: 01/15/1999
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Horton, John Daniel Jr., Hollums, Scott, Roussel, Chris
• Granted Patent: US 6,928,109 B2
• Time in Patent Office: Days
• US Class Current: 725/111
• 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: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9057 Arrangements for supporting packet reassembly or resequencing

Abstract

Requests are processed to transmit data packets upstream from a cable modem to a cable headend in a manner that minimizes the use of CPU operations and/or memory capacity. Data packets to be transmitted upstream are stored at the cable modem. The data packets each have a given transmission data byte length value. Burst profiles are received successively at the cable modem. Each time a new bust profile is received, a set of physical data length values corresponding to respective transmission data byte length values is calculated from the parameters of the received burst profile. The calculated set of physical data length values is stored in memory so the individual values can be retrieved from the transmission data byte length values again and again, rather than being re-calculated each time a conversion is made from transmission data byte length values to physical data length values. The same set of physical data length values is used until a new burst profile is received by the cable modem.

Claims

1. A method for processing requests to transmit data packets upstream from a cable modem to a cable headend, the method comprising the steps of:

receiving burst profiles successively at the cable modem;

storing a data packet to be transmitted upstream, the data packet having a given transmission data byte length value;

calculating a set of physical data length values corresponding to respective transmission data byte length values each time that a new burst profile is received;

storing the calculated set of physical data length values in memory so they can be retrieved from the transmission data byte length values each time that a new burst profile is received to replace a previously calculated set of physical data length values;

retrieving the physical data length value corresponding to the given transmission data byte length value from the stored set; and

transmitting from the cable modem a request message that includes the retrieved physical data length value.