Cable modem with dribble grant access system and method

• US 6,807,193 B1
• Filed: 06/20/2000
• Issued: 10/19/2004
• Est. Priority Date: 06/20/2000
• Status: Expired due to Fees

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Beser, Nurettin B.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Fox, Jamal A.
• Application Number:
  US09/597,841
• Time in Patent Office: 1,582 Days
• Field of Search: 370/346, 370/449, 370/465, 370/351, 370/216, 370/248, 370/254, 370/431, 370/519, 370/356, 370/443, 370/447, 370/451, 370/461, 370/462, 370/493, 370/494, 370/495, 370/352, 370/442, 370/487, 370/490, 704/246, 704/231, 725/111
• US Class Current: 370/498
• CPC Class Codes: H04L 12/2801 Broadband local area networks

Abstract

A modem, communications system and method are provided with a transmitter and a receiver connected to a modem termination system (CMTS) by a medium. The modem has a memory forming a transmit queue including voice and video. The modem has a controller for sending data units from the receive queue to CMTS. The modem requests unsolicited grant service (UGS) from CMTS when the frame controller detects periodic stream to transmit. Upon detecting a data accumulation in the receive queue, the controller asserts a queue indicator. The Modem receives an occasional extra grant per interval and uses these grants until the queue indicator is not asserted. According to another feature, during transmission, the modem requests subsequent grants in a subsequent interval using an extended header having multiple bits for requesting the multiple grants. The CMTS allocates at least an extra grant to form a grant burst in response to the request.

Claims

1. A cable modem comprising:

a transmitter connected to a modem termination system by a medium;

a receiver connected to the modem termination system by the cable;

a memory forming a transmit queue;

an input/output supplying generated data units, said data units from time to time including voice communications data units;

a data unit controller for sending data units to the input/output from the receive queue and transmitting data units to the modem termination system via the transmit queue and receiving unsolicited grant service (UGS) from the modem termination system, providing fixed grants of bandwidth time slots, on a real time basis, the controller using unsolicited data grants for transmission to the modem termination system and for asserting a queue indicator, in a transmission to the modem termination system upon detecting data units accumulating in the transmission queue and receiving in response an occasional extra grant and using occasional extra grant to send the accumulated data units until the queue indicator is not asserted.

2. A cable modem according to claim 1, wherein the data unit controller receives polled requests from the modem termination system when UGS is not active and upon the data unit controller detecting activity, the cable modem requests UGS in the form of enough bandwidth for one grant per transmission interval and requests subsequent grants in a subsequent interval using an extended header having multiple bits for the multiple grants.

3. A cable modem according to claim 1, wherein when new UGS is requested, the modem termination system bursts extra grants to clear out any packet buildup in the memory.

4. A cable modem according to claim 2, wherein when the cable modem is receiving UGS and then detects inactivity on a transmission subflow and asks for one less grant, there will be a delay in time before the reduction in grants occurs during which the data unit controller empties the transmit queue.

5. A cable modem according to claim 1, wherein when the cable modem is receiving UGS and detects no activity on any of its transmission subflows, it will send one packet with an active grants field of the header associated with the transmission set to zero grants, and then cease transmission causing the modem termination system to switch from UGS mode to real time polling.

6. A cable modem according to claim 1, wherein the cable modem generates packets or receives packets from the input/output based on voice signals formed with voice activity detection (VAD) or silence suppression, namely a voice technique in which the transmitting including voice samples occurs only when there is significant voice energy present wherein a receiving unit will compensate for the silence intervals by inserting silence or comfort noise equal to the perceived background noise of the conversation.

7. A method for transmitting data units from a modem to a terminating system, the method comprising the steps of:

providing a modem with a transmitter connected to a cable modem termination system (CMTS) by a cable and with a receiver connected to the CMTS by the cable;

providing a memory forming a transmit queue;

providing an input supplying generated data units, including from time to time voice communications data units;

receiving unsolicited grant service (UGS) from the CMTS, providing fixed unsolicited data grants of bandwidth time slots to the modem, on a real time basis;

using the unsolicited data grants for transmission to the CMTS and for asserting a queue indicator, in a transmission to the CMTS upon detecting a data units accumulating in the transmit queue; and

receiving in response an occasional extra grant per transmission interval until the queue indicator is not asserted.

8. A method according to claim 7, wherein the data unit controller receives polled requests from the CMTS when UGS is not active and upon the modem detecting activity including voice communications data units, the cable modem requests UGS in the form of enough bandwidth for one grant per transmission interval and requests subsequent grants in a subsequent interval using an extended header having multiple bits for requesting the multiple grants.

9. A method according to claim 7, wherein when new UGS is added, the CMTS bursts extra grants to clear out any packet buildup in the memory.

10. A method according to claim 7, wherein when the cable modem is receiving UGS and then detects inactivity on a transmission subflow and asks for one less grant, there will be a delay in time before the reduction in grants occurs and the data unit controller empties the transmit queue.

11. A method according to claim 7, wherein when the cable modem is receiving UGS and detects no activity on any of its transmission subflows, it will send one packet with an active grants field of the header associated with the transmission set to zero grants, and then cease transmission causing the CMTS to switch from UGS mode to Real Time Polling mode.

12. A method according to claim 7, wherein the cable modem generates packets or receives packets from the input/output based on voice signals formed with a voice technique in which data is transmitted including voice samples only when there is significant voice energy present wherein a receiving unit will compensate for the silence intervals by inserting silence or comfort noise equal to the perceived background noise of the conversation.

13. A data unit transmission system, comprising:

a cable modem termination system (CMTS);

a cable modem (CM) with a transceiver connected to the CMTS by a cable, the CM having at least one memory forming a transmit queue and an input supplying generated data units, including from time to time voice communications data units;

a telephone including an audio input, a packet generator and a packet output connected to the input of the CM, with data units supplied by the telephone being stored in the transmit queue before transmission to the CMTS;

unsolicited grant service (UGS) from the CMTS to the CM, providing fixed unsolicited data grants of bandwidth time slots, on a real time basis;

transmissions form the CM to the CMTS using the unsolicited data grants for voice communications data units and for asserting a queue indicator, in a transmission to the CMTS, upon detecting data units accumulating in the transmission queue; and

allocation of an extra grant during one or successive grant intervals until the queue indicator is not asserted.

14. A system according to claim 13, wherein the data unit controller receives polled requests from the CMTS when UGS is not active and upon the modem detecting activity including voice communications data units, the cable modem requests UGS in the form of enough bandwidth for one grant per transmission interval and in an extended header, using the unsolicited grants, the CM and requests a grant burst in of subsequent grants in a subsequent interval using an extended header having multiple bits for requesting the multiple grants the grant burst being requested based on the status of the transmission queue.

15. A system according to claim 13, wherein when new UGS is added, the CMTS bursts extra grants to clear out any packet buildup in the memory.

16. A system according to claim 13, wherein when the cable modem is receiving UGS and then detects inactivity on a transmission subflow and asks for one less grant, there will be a delay in time before the reduction in grants occurs and the data unit controller empties the transmit queue.

17. A system according to claim 13, wherein when the cable modem is receiving UGS and detects no activity on any of its transmission subflows, it will send one packet with an active grants field of the header associated with the transmission set to zero grants, and then cease transmission causing the CMTS to switch from UGS mode to Real Time Polling mode.

18. A system according to claim 13, wherein the cable modem generates packets or receives packets from the input/output based on voice signals formed with a voice technique in which the transmitting including voice samples only when there is significant voice energy present wherein a receiving unit will compensate for the silence intervals by inserting silence or comfort noise equal to the perceived background noise of the conversation.

19. A data unit transmission system, comprising:

a termination system and a unit with a transmitter connected to the termination system by a medium, the unit having a transmit queue;

a packet generator connected to the unit, supplying generated data units to the transmit queue for transmission to the termination system, the data at times including voice communications packets or other packets based on real time service flows that generate fixed size data packets on a periodic basis;

requesting unsolicited grant service (UGS) by the unit from the termination system upon detecting packets based on the real time service flows that generate fixed size data packets on a periodic basis;

providing UGS from the termination system to the unit, to providing fixed unsolicited data grants of bandwidth time slots, on a real time basis;

transmitting from the unit to the termination system using the unsolicited data grants for sending data units from the unit to the termination system;

during the step of transmitting, requesting subsequent grants in a subsequent interval using an extended header having multiple bits for requesting the multiple grants; and

allocating at least an extra grant to form a grant burst in response to the multiple bits for requesting the multiple grants.