Method and apparatus for downlink data buffering considering cross carrier scheduling in a wireless communication system

A method for a network, the method comprising:

• configuring a first serving cell and a second serving cell to a User Equipment (UE);
• transmitting a second Physical Downlink Control Channel (PDCCH) to the UE on the second serving cell, wherein the second PDCCH schedules a second Physical Downlink Shared Channel (PDSCH) transmitted on the second serving cell, and a time offset between reception of a Downlink Control Information (DCI) of the second PDCCH and the second PDSCH is allowed to be less than a threshold;
• transmitting a first PDCCH to the UE on the second serving cell, wherein the first PDCCH schedules a first PDSCH transmitted on the first serving cell;
• and
• preventing from setting or configuring the time offset between reception of a DCI of the first PDCCH and the first PDSCH to be less than the threshold.

A User Equipment (UE), comprising:

• a control circuit;
• a processor installed in the control circuit;
• and
• a memory installed in the control circuit and coupled to the processor;
• wherein the processor is configured to execute a program code stored in the memory to:
• receive a configuration of a first serving cell and a second serving cell from a network;
• receive and/or monitor a first Physical Downlink Control Channel (PDCCH) transmitted on the second serving cell, wherein the first PDCCH schedules a first Physical Downlink Shared Channel (PDSCH) transmitted on the first serving cell;
• receive and/or monitor a second PDCCH transmitted on the second serving cell, wherein the second PDCCH schedules a second PDSCH transmitted on the second serving cell;
• receive and/or buffer the second PDSCH via a Transmission Configuration Indication (TCI) state used for PDCCH quasi co-location indication (QCI) of a Control Resource Set (CORESET) with the lowest CORESET-ID in the latest slot in which one or more CORESETs are configured for the UE, before the UE decodes successfully the second PDCCH;
• and
• not receive and/or buffer the first PDSCH before the UE decodes successfully the first PDCCH.