Cable modem with dribble grant access system and method

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.

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.

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.