Multi-stage sidelink control information

A method of controlling sidelink radio transmissions in a wireless communication network, the method comprising:

• based on assistance information stored in a radio device, the radio device determining first sidelink control information, the assistance information relating the first sidelink control information to a configuration for transmission of second sidelink control information, the first sidelink control information comprising information for sensing-based allocation of radio resources for a sidelink radio transmission;
• the radio device sending the first sidelink control information to a further radio device;
• based on the configuration, the radio device sending the second sidelink control information to the further radio device;
• and
• based on the second sidelink control information, the radio device sending a sidelink radio transmission to the further radio device.

A radio device for a wireless communication network, the radio device comprising:

• a processor;
• and
• a memory coupled with the processor, the memory containing instructions executable by the processor whereby the radio device is operative to:
• receive first sidelink control information from a further radio device, the first sidelink control information comprising information for sensing-based allocation of radio resources for a sidelink radio transmission;
• based on assistance information stored in the radio device and the received first sidelink control information, determine a configuration for transmission of second sidelink control information;
• based on the determined configuration for transmission of the second sidelink control information, receive the second sidelink control information from the further radio device;
• and
• based on the received second sidelink control information, receive a sidelink radio transmission from the further radio device.

A radio device for a wireless communication network, the radio device comprising:

• a processor;
• and
• a memory coupled with the processor, the memory containing instructions executable by the processor whereby the radio device is operative to:
• based on assistance information stored in the radio device, determine first sidelink control information, the assistance information relating the first sidelink control information to a configuration for transmission of second sidelink control information, wherein the first sidelink control information comprises information for sensing-based allocation of radio resources for a sidelink radio transmission;
• send the first sidelink control information to a further radio device;
• based on the configuration, send the second sidelink control information to the further radio device;
• and
• based on the second sidelink control information, send a sidelink radio transmission to the further radio device.