Cable modem system with sample and packet synchronization

• US 20060050689A1
• Filed: 10/21/2005
• Published: 03/09/2006
• Est. Priority Date: 02/12/1999
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Horton, John D. Jr., Rabenko, Theodore F., Thi, James C. H.
• Granted Patent: US 7,801,176 B2
• Time in Patent Office: Days
• US Class Current: 370/356
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

A method and system of processing sampled voice packets from a voice packet sender for transmission over a bit-rate sampled data transmission system, such as by a cable modem over a cable modem termination system, to a voice packet recipient. Unsolicited grant arrivals in response to a request from the voice packet sender coupled to the cable modem are determined. The storing of sampled voice packets is synchronized with the unsolicited grant arrivals. Upon receipt of an unsolicited grant arrival, currently stored sampled voice packets are transmitted to the cable modem for further transmission to the voice packet recipient over the cable modem termination system.

Claims

1. A method for transmitting voice packets over a transmission system, the method comprising:

sampling voice packets using a clock derived from and synchronized with a clock of a cable modem;

determining time needed between adjacent unsolicited grant arrivals for storing the sampled voice packets; and

transmitting the voice packets over the transmission system, upon receipt of an unsolicited grant arrival.

2. The method of claim 1 further comprising:

determining a transmission window based on grant arrivals intervals; and

transmitting the voice packets over the transmission system during the determined transmission window.

3. The method of claim 1 further comprising:

storing the sampled voice packets; and

scheduling processing of the stored sample packets to be ready for transmission at a next unsolicited grant arrival.

4. The method of claim 1, wherein the cable modem is coupled to a cable modem termination system and the voice packets are transmitted to a Public Switched Telephone Network (PSTN) gateway by synchronizing a clock of the cable modem termination system coupled to the cable modem with a clock of the PSTN.

5. The method of claim 1, further comprising processing the sampled packets for voice compression.

6. A system for transmitting voice packets over a transmission system comprising:

means for sampling voice packets using a clock derived from and synchronized with a clock of a cable modem;

means for determining time needed between adjacent unsolicited grant arrivals for storing the sampled voice packets; and

means for transmitting the voice packets over the transmission system, upon receipt of an unsolicited grant arrival.

7. The system of claim 6 further comprising:

means for determining a transmission window based on grant arrivals intervals; and

means for transmitting the voice packets over the transmission system during the determined transmission window.

8. The system of claim 6 further comprising:

means for storing the sampled voice packets; and

means for scheduling processing of the stored sample packets to be ready for transmission at a next unsolicited grant arrival.

9. The system of claim 6, wherein the cable modem is coupled to a cable modem termination system and the voice packets are transmitted to a Public Switched Telephone Network (PSTN) gateway by synchronizing a clock of the cable modem termination system coupled to the cable modem with a clock of the PSTN.