Method and apparatus for controlling semi-persistent scheduling

1. An user equipment supporting Semi-Persistent Scheduling (SPS), the user equipment comprising:

a receiver configure to

receive sidelink (SL) SPS radio network temporary identifier (RNTI) from a base station; and

receive a SL grant including downlink control information (DCI from the base station with a Physical Downlink Control Channel (PDCCH),

wherein the DCI comprises a SL SPS index field and an activation/release indication field if the DCI with Cyclic Redundancy Check (CRC) is scrambled with the SL SPS RNTI,

wherein a start subframe for Sidelink Control (SC) period is determined based on an offset value and a subframe in which the sidelink grant is received, and

wherein an index of a subframe for SC period is relative to System Frame Number (SFN) 0.

2. The user equipment of claim 1 , wherein a value for the SL SPS RNTI is determined as one of values which is described as below table.

Values (hexa-decimal)

RNTI

0001-FFF3

SL SPS RNTI

3. The user equipment of claim 1 , further comprising:

a processor configure to scramble PDCCH by using the SL SPS RNTI, wherein the DCI scrambled by the SL SPS RNTI enable the user equipment to operate an SL SPS associated with a direct communication between the user equipment and another user equipment.

4. The user equipment of claim 1 , wherein the SL SPS index field has a 3-bits field, and

wherein a maximum quantity of a SL SPS configurations for the user equipment is eight.

5. The user equipment of claim 4 , wherein a 1-bit field of the 3-bits field is a activation/release indication field.

6. The user equipment of claim 1 , wherein the user equipment comprises one or more of: vehicle having a vehicle-to-vehicle (V2V) communication capability, a vehicle having a vehicle-to-pedestrian (V2P) communication capability, a vehicle having a vehicle-to-infrastructure (V2I) communication capability, or a vehicle having a vehicle-to-everything (V2X) communication capability.

7. The user equipment of claim 1 , wherein the receiver further configured to receive a radio resource control (RRC) message comprising release information (implicitReleaseAfter).

8. The user equipment of claim 7 , wherein SL grant is released when consecutive Medium Access Control Protocol Data Units (MAC PDUs) containing zero MAC Service Data Unit (SDU) is transmitted, and

wherein the number of the consecutive MAC PDUs is determined by the release information.