Reconfigurable intelligent surface (RIS) reservation for sidelink communications

A method for wireless communication by a reconfigurable intelligent surface (RIS), comprising:

• receiving, from a first sidelink (SL) user equipment (UE), a reservation message requesting reservation of the RIS;
• transmitting, to the first SL UE, a reservation confirmation message indicating an assignment of the RIS to the first SL UE based on receiving the reservation message;
• transmitting, to the first SL UE, a communication window message indicating a period of time associated with the assignment;
• receiving, within the period of time, a beam training sequence for beam training the RIS to identify a beam index, of a plurality of beam indices, that satisfies one or more beam selection criteria;
• transmitting, to the first SL UE, a beam selection message indicating the beam index;
• and
• receiving, within the period of time from the first SL UE via a beam associated with the beam index, data intended for transmission to a second SL UE.

A method for wireless communication by base station, comprising:

• transmitting, to a first sidelink (SL) user equipment (UE), a reservation confirmation message indicating an assignment of a reconfigurable intelligent surface (RIS) to the first SL UE;
• transmitting, to the first SL UE, a communication window message indicating a period of time associated with the assignment;
• receiving, from the RIS, a first beam selection message indicating a beam index, of a plurality of beam indices, that satisfies one or more beam selection criteria;
• and
• transmitting, to the first SL UE, a second beam selection message indicating the beam index.

An apparatus for wireless communications at a first sidelink (SL) user equipment (UE), comprising:

• a processor;
• and
• a memory coupled with the processor and storing instructions operable, when executed by the processor, to cause the apparatus to:
• receive a reservation confirmation message indicating an assignment of a reconfigurable intelligent surface (RIS) to the first SL UE;
• receive a communication window message indicating a period of time associated with the assignment;
• transmit, within the period of time, a beam training sequence for beam training the RIS to identify a beam index, of a plurality of beam indices, that satisfies one or more beam selection criteria;
• and
• transmit, within the period of time via a beam associated with the beam index, data intended for transmission to a second SL UE via the RIS.