A wireless terminal for a wireless communication, the wireless terminal includes: a memory that includes a buffer configured to store uplink data, wherein the uplink data is configured to be transmitted; and a controller configured to transmit a buffer status report, the buffer status report including a first index, wherein the first index is one of a plurality of buffer status indices and corresponds to a buffer size indicating a size of the uplink data stored in the buffer, wherein the memory is configured to store a buffer status table in which a range from a minimum value of the buffer to a maximum value of the buffer is divided into a plurality of subranges, the plurality of subranges being associated with a part of the plurality of buffer status indices, and a rest of the plurality of buffer status indices are associated with one or more reserved fields.