Method and apparatus for configuring sidelink discontinuous reception in a wireless communication system

A User Equipment (UE), comprising:

• a control circuit;
• a processor installed in the control circuit;
• and
• a memory installed in the control circuit and operatively coupled to the processor;
• wherein the processor is configured to execute a program code stored in the memory to:
• obtain or be configured with a sidelink DRX configuration applied for a the sidelink groupcast communication associated with a group, wherein the sidelink DRX configuration comprises at least one of an on-duration timer length used for determining an on-duration at the beginning of each sidelink DRX cycle or a cycle length used for determining a length of each sidelink DRX cycle;
• determine an identifier associated with the group;
• derive or determine a time to start of on-duration for each sidelink DRX cycle or start of each sidelink DRX cycle based on (i) a derived value of “(part of the identifier) mod (the cycle length)” or (ii) a derived value of “(the identifier) mod (the cycle length)”;
• and
• transmit a sidelink control information associated with the group on a sidelink control channel in a period, wherein the period is determined based on the sidelink DRX configuration and the time to start of on-duration for each sidelink DRX cycle or start of each sidelink DRX cycle.

A non-transitory computer-readable medium comprising processor-executable instructions that when executed by a User Equipment (UE) cause performance of operations, the operations comprising:

• obtaining or being configured with a sidelink DRX configuration applied for a sidelink groupcast communication associated with a group, wherein the sidelink DRX configuration comprises at least one of an on-duration timer length used for determining an on-duration at the beginning of each sidelink DRX cycle or a cycle length used for determining a length of each sidelink DRX cycle;
• determining an identifier associated with the group;
• deriving or determining a time to start of on-duration for each sidelink DRX cycle or start of each sidelink DRX cycle based on (i) a derived value of “(part of the identifier) mod (the cycle length)” or (ii) a derived value of “(the identifier) mod (the cycle length)”;
• and
• transmitting a sidelink control information associated with the group on a sidelink control channel in a period, wherein the period is determined based on the sidelink DRX configuration and the time to start of on-duration for each sidelink DRX cycle or start of each sidelink DRX cycle.