Method and system for transmitting audio signals

1 . A method for transmitting audio signals, comprising:

establishing a wireless link utilizing Bluetooth LE Audio between an audio signal transmission unit and an audio signal receiver unit;

transmitting BIS data PDUs representative of an audio signal via the wireless link from the audio signal transmission unit to the audio signal receiver unit;

providing, by the audio signal transmission unit, a BIG control PDU with time-critical control data to be transmitted to the audio signal receiver unit as part of its payload, wherein a marked CRC value is provided in a standard CRC field of said BIG control PDU which is different from the standard CRC value of said BIG control PDU;

transmitting, by the audio signal transmission unit, the BIG control PDU via the wireless link to the audio signal receiver unit, and receiving, by the receiver unit, the BIG control PDU;

calculating, by the audio signal receiver unit, the standard CRC value of the received BIG control PDU and comparing the calculated standard CRC value with the value of the standard CRC field of the received BIG control PDU; and

analyzing, by the audio signal receiver unit, the received BIG control PDU as to whether or not the payload comprises time-critical control data, when the value of the standard CRC field of the received BIG control PDU does not match the calculated standard CRC value of the received BIG control PDU.

2 . The method of claim 1 , wherein the marked CRC value is provided by a first algorithm which calculates the standard CRC value and advertently corrupts the calculated standard CRC value, such as by adding a constant value to the standard CRC value or by inverting at least one bit of the payload when calculating the standard CRC value.

3 . The method of claim 1 , wherein the payload of the BIG control PDU includes a time-critical control data (TCCD) field for the time-critical control data and a software CRC (SCRC) field containing a SCRC value calculated by a second algorithm based on the time-critical control data in the TCCD field; and wherein the audio signal receiver unit, when the CRC value of the standard CRC field of the BIG control PDU was found to not match with the standard CRC value, calculates, using the second algorithm, the SCRC value of the data in the TCCD field of the BIG control PDU received from the audio signal transmission unit and compares the calculated SCRC value with the value of the SCRC field of the received BIG control PDU so as to verify the data in the TCCD field as valid control data for the audio signal receiver unit.

4 . The method of claim 1 , wherein the marked CRC value is calculated as a customized CRC value by a first algorithm from the payload of the BIG Control PDU, wherein the audio signal receiver unit, when the value of the standard CRC field of the received BIG control PDU was found to not match the standard CRC value, calculates, using the first algorithm, the customized CRC value of the received BIG control PDU, and wherein the time-critical control data in the received BIG control PDU is verified as valid control data for the audio signal receiver unit when the customized CRC value is found to match with the value in the standard CRC field of the received BIG control PDU.

5 . A method for transmitting audio signals, comprising:

establishing a wireless link utilizing Bluetooth LE Audio between an audio signal transmission unit and an audio signal receiver unit;

transmitting BIS data PDUs representative of an audio signal via the wireless link from the audio signal transmission unit to the audio signal receiver unit;

providing, by the audio signal transmission unit, a BIG control PDU with time-critical control data to be transmitted to the audio signal receiver unit as part of its payload, wherein a marked CRC value is provided in a standard CRC field of said BIG control PDU which is different from the standard CRC value of said BIG control PDU and wherein the marked CRC value is calculated as a customized CRC value by a first algorithm from the payload of the BIG Control PDU;

transmitting, by the audio signal transmission unit, the BIG control PDU via the wireless link to the audio signal receiver unit, and receiving, by the receiver unit, the BIG control PDU;

analyzing, by the audio signal receiver unit, the received BIG Control PDU as to whether or not the payload comprises time-critical control data, wherein the audio signal receiver unit calculates, using the first algorithm, the customized CRC value of the received BIG control PDU, and wherein the time-critical control data in the received BIG control PDU is verified as valid control data for the audio signal receiver unit when the customized CRC value is found to match with the value in the standard CRC field of the received BIG control PDU; and

when the customized CRC value is found to not match with the value in the standard CRC field of the received BIG control PDU, calculating, by the audio signal receiver unit, the standard CRC value of the received BIG control PDU and comparing the calculated standard CRC value with the value of the standard CRC field of the received BIG control PDU, wherein the audio signal receiver unit considers the BIG control PDU to contain Bluetooth LE Audio control data when the calculated standard CRC value matches with the value of the standard CRC field of the received BIG control PDU.

6 . The method of claim 5 , wherein a Bluetooth LE Audio controller of the audio signal receiver unit ignores the BIG control PDU as not containing Bluetooth LE Audio control data when the Bluetooth LE Audio controller finds a mismatch of the value of the standard CRC field of the received BIG control PDU with the standard CRC value.

7 . The method of claim 5 , wherein the transmitting of time-critical control data by the audio signal transmission unit as part of the BIG control PDU follows the transmission of the BIS data PDUs in a current BIG event.

8 . The method of claim 5 , wherein the time-critical control data is used by the audio signal receiving unit for controlling processing of the audio signal received from the audio signal transmission unit.

9 . The method of claim 8 , wherein the time-critical control data includes at least one of: information as to whether or not speech is absent in the audio signal to be transmitted, information regarding a surrounding noise level in the audio signal to be transmitted, and information regarding current movement of the audio signal transmission unit in space.

10 . The method of claim 5 , wherein the audio signal transmission unit is designed as a wireless microphone arrangement to be worn or held by a speaker for capturing the speaker's voice as the audio signal to be transmitted, and wherein the audio signal receiver unit is a hearing device for stimulating the hearing of a user according to the audio signal received from the audio signal transmission unit.

11 . The method of claim 5 , wherein the audio signal transmission unit broadcasts the audio signal via the wireless link to a plurality of audio signal receiver units, including said audio signal receiver unit.

12 . The method of claim 11 , wherein the plurality of audio signal receiving units includes at least one audio signal receiver unit which is programmed to generally ignore the BIG control PDU when its Bluetooth LE Audio controller finds a mismatch of the CRC value in the standard CRC field of the BIG control PDU with the standard CRC value.

13 . The method of claim 5 , wherein the audio signal transmission unit transmits time-critical control data not only as part of the payload of the BIG control PDU but in addition also as part of periodic advertising packets which the audio signal transmission unit periodically transmits via the wireless link.

14 . A system for transmitting audio signals, comprising an audio signal transmission unit and an audio signal receiver unit, both of which include a wireless interface for establishing a wireless link utilizing Bluetooth LE Audio between the audio signal transmission unit and the audio signal receiver unit;

the audio signal transmission unit being configured to

transmit BIS data PDUs representative of an audio signal via the wireless link from the audio signal transmission unit to the audio signal receiver unit;

provide a BIG control PDU with time-critical control data to be transmitted to the audio signal receiver unit as part of its payload, wherein a marked CRC value is provided in a standard CRC field of said BIG control PDU which is different from the standard CRC value of said BIG control PDU;

transmit the BIG control PDU via the wireless link to the audio signal receiver unit; the audio signal receiver unit being configured to

calculate the standard CRC value of the BIG control PDU received from the audio signal transmission unit;

compare the standard CRC value with the value of the standard CRC field of the received BIG control PDU; and

analyze the received BIG control PDU as to whether or not the payload comprises time-critical control data, when the value of the standard CRC field of the received BIG control PDU does not match the calculated standard CRC value of the received BIG control PDU.

15 . A system for transmitting audio signals, comprising an audio signal transmission unit and an audio signal receiver unit, both of which include a wireless interface for establishing a wireless link utilizing Bluetooth LE Audio between the audio signal transmission unit and the audio signal receiver unit;

the audio signal transmission unit being configured to

transmit BIS data PDUs representative of an audio signal via the wireless link from the audio signal transmission unit to the audio signal receiver unit;

provide a BIG control PDU with time-critical control data to be transmitted to the audio signal receiver unit as part of its payload, wherein a marked CRC value is provided in the standard CRC field of said BIG control PDU which is different from the standard CRC value of said BIG control PDU, and wherein the marked CRC value is calculated as a customized CRC value by a first algorithm from the payload of the BIG Control PDU; and

transmit the BIG control PDU via the wireless link to the audio signal receiver unit;

the audio signal receiver unit being configured to

analyze the received BIG Control PDU as to whether or not the payload comprises time-critical control data by calculating, using the first algorithm, the customized CRC value of the received BIG control PDU, wherein:

when the customized CRC value is found to match with the value in a standard CRC field of the received BIG control PDU the time-critical control data in the received BIG control PDU is verified as valid control data for the audio signal receiver unit; and

when the customized CRC value is found to not match with the value in the standard CRC field of the received BIG control PDU, the standard CRC value of the received BIG control PDU is calculated and is compared with the value of the standard CRC field of the received BIG control PDU, wherein the BIG control PDU is considered to contain Bluetooth LE Audio control data when the calculated standard CRC value matches with the value of the standard CRC field of the received BIG control PDU.