An apparatus may be configured to: determine to report an amount of data in a transmission buffer; determine respective values for a plurality of buffer-size fields that are configured to jointly indicate the amount of data in the transmission buffer, wherein the respective values are determined based on the amount of data in the transmission buffer; generate a buffer-status report, wherein the buffer-status report comprises, at least, the plurality of buffer-size fields; generate a protocol data unit, wherein the protocol data unit comprises, at least, the buffer-status report; and transmit the protocol data unit. An apparatus may be configured to: receive, from a user equipment, a protocol data unit; and determine at least one of: a lower bound for the data in the transmission buffer, or an upper bound for the data in the transmission buffer based on the plurality of buffer-size fields.