Method and apparatus for reporting data status in mobile wireless communication system

A terminal comprising:

• a transceiver,
• a memory, and
• a controller coupled to the transceiver and the memory, wherein the controller is configured to:
• receive, from a base station, a Radio Resource Control (RRC) message, wherein the RRC message comprises:
• one or more sets of parameters related to logical channel, wherein each of the one or more sets of parameters related to logical channel comprises configuration parameters of a logical channel;
• and
• one or more sets of parameters related to logical channel group, wherein each of the one or more sets of parameters related to logical channel group comprises configuration parameters of a logical channel group;
• trigger a first Medium Access Control (MAC) Control Element (CE) or a second MAC CE;
• and
• transmit, to the base station, the first MAC CE or the second MAC CE,
• wherein the first MAC CE is triggered based on existence of uplink data of a first logical channel,
• wherein the second MAC CE is triggered based on a remaining time until one or more protocol data units (PDUs) of a second logical channel group are discarded,
• wherein a logical channel is the first logical channel in case that a parameter indicating a logical channel group identifier is included in a set of parameters related to logical channel of the logical channel,
• wherein a logical channel group is the second logical channel group in case that a parameter related to a remaining time is included in a set of parameters related to logical channel group of the logical channel group,
• wherein the first MAC CE comprises:
• one or more buffer size fields;
• and
• one or more buffer size table fields, and
• wherein the second MAC CE comprises:
• one or more buffer size fields;
• one or more buffer size table fields;
• and
• one or more delay fields.