Digital speech interpolation method and apparatus

A method for communicating digital speech on a transmit link between a communication unit and a switching facility and on a receive link between the switching facility and the communication unit, wherein the digital speech is communicated during multiple timeslots and at multiple carrier frequencies, and a combination of a carrier frequency of the multiple carrier frequencies and a timeslot of the multiple timeslots can be allocated for a burst of the digital speech when the combination has not been allocated for a different burst, the method comprising the steps of:

• a) determining, by the switching facility, the control channel frequency from the multiple carrier frequencies and the control channel timeslot from the multiple timeslots;
• b) sending second parameters defining the control channel frequency and the control channel timeslot to the communication unit;
• c) determining, by the communication unit, whether a speech frame is detected;
• d) when the speech frame is detected, sending a speech detected indicator (SDI) to the switching facility at the control channel frequency and the control channel timeslot;
• e) allocating, by the switching facility, a transmit link traffic timeslot of the multiple timeslots and a transmit link traffic frequency of the multiple carrier frequencies in response to the SDI, wherein the transmit link traffic timeslot and the transmit link traffic frequency are allocated only for a duration of the speech frame;
• f) sending first parameters defining the transmit link traffic frequency and the transmit link traffic timeslot to the communication unit;
• g) adjusting a communication unit transmission frequency to the transmit link traffic frequency;
• h) constructing a traffic burst by the communication unit which contains information describing the speech frame;
• and
• i) transmitting the traffic burst at the transmit link traffic frequency during the transmit link traffic timeslot.

A method for communicating digital speech on a transmit link between a communication unit and a switching facility and on a receive link between the switching facility and the communication unit, wherein the digital speech is communicated during multiple timeslots and at multiple carrier frequencies, and a combination of a carrier frequency of the multiple carrier frequencies and a timeslot of the multiple timeslots can be allocated for a burst of the digital speech when the combination has not been allocated for a different burst, the method comprising the steps of:

• a) determining, by the communication unit, whether a speech frame is detected;
• b) when the speech frame is detected, sending a speech detected indicator (SDI) to the switching facility;
• c) receiving first parameters defining a transmit link traffic timeslot of the multiple timeslots and a transmit link traffic frequency of the multiple carrier frequencies from the switching facility, wherein the transmit link traffic timeslot and the transmit link traffic frequency were allocated by the switching facility in response to the SDI, and the transmit link traffic frequency and the transmit link traffic timeslot are allocated only for a duration of the speech frame;
• d) adjusting a communication unit transmission frequency to the transmit link traffic frequency;
• e) constructing a traffic burst by the communication unit;
• and
• f) transmitting the traffic burst at the transmit link traffic frequency during the transmit link traffic timeslot.

A method for communicating digital speech on a transmit link between a communication unit and a switching facility and on a receive link between the switching facility and the communication unit, wherein the digital speech is communicated during multiple timeslots and at multiple carrier frequencies, and a combination of a carrier frequency of the multiple carrier frequencies and a timeslot of the multiple timeslots can be allocated for a burst of the digital speech when the combination has not been allocated for a different burst, the method comprising the steps of:

• a) receiving a speech detected indicator (SDI) from the communication unit after the communication unit detects a speech frame;
• b) allocating, by the switching facility, a transmit link traffic frequency of the multiple carrier frequencies and a transmit link traffic timeslot of the multiple timeslots in response to the SDI for the communication unit to use for the speech frame, wherein the transmit link traffic frequency and the transmit link traffic timeslot are allocated only for a duration of the speech frame;
• c) sending first parameters defining the transmit link traffic frequency and the transmit link traffic timeslot to the communication unit;
• and
• d) receiving a traffic burst from the communication unit at the transmit link traffic frequency and during the transmit link traffic timeslot.

A method for communicating digital speech between a communication unit and a switching facility using a time division multiple access (TDMA), frequency division multiple access (FDMA) protocol comprising a receive link control burst segment, a transmit link control burst segment, a transmit link traffic burst segment, and a receive link traffic burst segment, each segment being separated from each other segment in a time domain, the method comprising the steps of:

• a) receiving, by the switching facility, a speech detected indicator (SDI) in the transmit link control burst segment, wherein the SDI is sent by the communication unit each time the communication unit detects a speech frame;
• b) sending, by the switching facility in response to the SDI, first parameters in the receive link control burst segment, wherein the first parameters describe a transmit link traffic frequency and a transmit link traffic timeslot at which the communication unit should send a transmit link traffic burst;
• c) sending, by the switching facility, second parameters in the receive link control burst segment, wherein the second parameters describe a receive link traffic frequency and a receive link traffic timeslot at which the communication unit should receive a receive link traffic burst;
• d) receiving, by the switching facility, the transmit link traffic burst from the communication unit at the transmit link traffic frequency and during the transmit link traffic timeslot;
• and
• e) sending, by the switching facility, the receive link traffic burst to the communication unit at the receive link traffic frequency and during the receive link traffic timeslot.

A method for communicating digital speech on a transmit link between a communication unit and a switching facility and on a receive link between the switching facility and the communication unit, wherein the digital speech is communicated during multiple timeslots and at multiple carrier frequencies, and a combination of a carrier frequency of the multiple carrier frequencies and a timeslot of the multiple timeslots can be allocated for a burst of the digital speech when the combination has not been allocated for a different burst, the method comprising the steps of:

• a) sending, by the communication unit, a speech detected indicator (SDI) to the switching facility when the communication unit detects a speech frame;
• b) sending, by the switching facility, first parameters to the communication unit in response to the SDI, wherein the first parameters describe a transmit link traffic frequency and a transmit link traffic timeslot which the communication unit must use for transmission of the speech frame, and wherein the transmit link traffic frequency and the transmit link traffic timeslot are allocated only for a duration of the speech frame;
• and
• c) transmitting, by the communication unit, a transmit link traffic burst which contains an encoded representation of the speech frame, wherein the transmit link traffic burst is transmitted at the transmit link traffic frequency and during the transmit link traffic timeslot.

A communication unit comprising:

• a speech detector for determining whether a speech frame is detected;
• a controller coupled to the speech detector for sending a speech detected indicator (SDI) to a switching facility when the speech frame is detected, receiving an allocation message from the switching facility in response to the SDI, determining, from the allocation message, a transmit link traffic frequency and a transmit link traffic timeslot at which the communication unit should transmit a transmit link traffic burst which contains an encoded representation of the speech frame, wherein the transmit link traffic frequency and the transmit link traffic timeslot are allocated only for a duration of the speech frame;
• a vocoder coupled to the speech detector for creating the encoded representation of the speech frame;
• and
• a transmitter coupled to the controller for transmitting the transmit link traffic burst and for transmitting the SDI.

A switching facility used in a communication system where available spectrum is divided into multiple carrier frequencies, multiple timeslots exist for each of the multiple carrier frequencies, a reuse unit is a communication opportunity defined by a combination of a carrier frequency of the multiple carrier frequencies and a timeslot of the multiple timeslots, transmit link traffic is traffic from a communication unit to the switching facility, and receive link traffic is traffic from the switching facility to the communication unit, the switching facility comprising:

• a controller for allocating a transmit link traffic frequency from the multiple carrier frequencies and a transmit link traffic timeslot from the multiple timeslots in response to a speech detected indicator (SDI), wherein the SDI is sent by the communication unit each time that the communication unit has detected a speech frame, the controller further for creating an allocation message containing parameters describing the transmit link traffic frequency and the transmit link traffic timeslot;
• a receiver coupled to the controller for receiving the SDI from the communication unit, and for receiving a traffic burst containing an encoded representation of the speech frame at the transmit link traffic frequency and during the transmit link traffic timeslot;
• and
• a transmitter coupled to the controller for sending the allocation message to the communication unit.