Method and apparatus for operating buffer state report in wireless communication system

A wireless user device comprising:

• an antenna;
• a transceiver to communicate with a base station via the antenna;
• one or more processors;
• and
• memory storing instructions that, when executed by the one or more processors, cause the wireless user device to:
• receive, from the base station, one or more messages comprising information of a resource allocation mode for direct data transmission between wireless user devices;
• determine a radio link failure (RLF) associated with a radio resource control (RRC) connection;
• and
• based on the determined RLF:
• cancel buffer status reports (BSR s) for direct data transmission, wherein the canceled BSRs for direct data transmission are associated with at least one direct data transmission, between wireless user devices, scheduled by the base station;
• select, based on a configuration parameter indicating a plurality of resources of a resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in an exceptional condition, at least one resource associated with the exceptional condition;
• and
• transmit, via the at least one resource associated with the exceptional condition, data to a second wireless user device.

A method comprising:

• receiving, by a wireless user device from a base station, one or more messages comprising information of a resource allocation mode for direct data transmission between wireless user devices;
• triggering, while the wireless user device is operating in the resource allocation mode, a buffer status report (BSR) for direct data transmission;
• determining, after the triggering, that a timer associated with a handover of the wireless user device is running;
• and
• based on the determining that the timer associated with the handover of the wireless user device is running:
• canceling BSRs for direct data transmission, wherein the canceled BSRs for direct data transmission are associated with at least one direct data transmission, between wireless user devices, scheduled by the base station and associated with the resource allocation mode;
• selecting, based on a configuration parameter indicating a plurality of resources of a resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in an exceptional condition, at least one resource associated with the exceptional condition;
• and
• transmitting, via the at least one resource associated with the exceptional condition, data to a second wireless user device.