Methods and apparatuses for s-ssb transmission in unlicensed spectra

A base station (BS), comprising:

• at least one memory;
• and
• at least one processor coupled with the at least one memory and configured to cause the base station to:
• transmit configuration information for sidelink synchronization signal block (S-SSB) in an unlicensed spectrum, wherein the configuration information includes at least one of the following:
• condition(s) for determining a channel access failure prior to a target S-SSB occasion based on a listen before talk (LBT) type 1 procedure;
• a first mapping between channel access priority class (CAPC) value(s) and priority(ies) for synchronization reference;
• a second mapping between CAPC value(s) and channel occupancy time(s) (COT(s));
• or
• a third mapping between length(s) of cyclic prefix extension (CPE) and priority(ies) for synchronization reference.

A method performed by a user equipment (UE), the method comprising:

• obtaining configuration information for sidelink synchronization signal block (S-SSB) in an unlicensed spectrum based on configuration or pre-configuration, wherein the configuration information includes condition(s) for determining a channel access failure prior to a target S-SSB occasion based on a listen before talk (LBT) type 1 procedure;
• performing a first LBT type 1 procedure associated with a first S-SSB occasion to initiate a first S-SSB channel occupancy starting from the first S-SSB occasion;
• performing at least one of the following operations in response to determining a channel access failure prior to the first S-SSB occasion based on the first LBT type 1 procedure and the configuration information:
• performing a second LBT type 1 procedure associated with a second S-SSB occasion next to the first S-SSB occasion to initiate a second S-SSB channel occupancy starting from the second S-SSB occasion;
• continuing to perform the first LBT type 1 procedure prior to the second S-SSB occasion to initiate a second S-SSB channel occupancy starting from the second S-SSB occasion;
• or
• performing a first LBT type 2 procedure;
• and
• transmitting an S-SSB on the first S-SSB occasion in response to a channel being available for access prior to the first S-SSB occasion based on the first LBT type 1 procedure.

A processor for wireless communication, comprising:

• at least one controller coupled with at least one memory and configured to cause the processor to:
• obtain configuration information for sidelink synchronization signal block (S-SSB) in an unlicensed spectrum based on configuration or pre-configuration, wherein the configuration information includes condition(s) for determining a channel access failure prior to a target S-SSB occasion based on a listen before talk (LBT) type 1 procedure;
• perform a first LBT type 1 procedure associated with a first S-SSB occasion to initiate a first S-SSB channel occupancy starting from the first S-SSB occasion;
• perform at least one of the following operations in response to determining a channel access failure prior to the first S-SSB occasion based on the first LBT type 1 procedure and the configuration information:
• performing a second LBT type 1 procedure associated with a second S-SSB occasion next to the first S-SSB occasion to initiate a second S-SSB channel occupancy starting from the second S-SSB occasion;
• continuing to perform the first LBT type 1 procedure prior to the second S-SSB occasion to initiate a second S-SSB channel occupancy starting from the second S-SSB occasion;
• or
• performing a first LBT type 2 procedure;
• and
• transmit an S-SSB on the first S-SSB occasion in response to a channel being available for access prior to the first S-SSB occasion based on the first LBT type 1 procedure.