Technologies for wireless communications can include communicating connection information that specifies one or more parameters of a connection between a base station and a wireless device. The connection information can be indicative of one or more of: a station identifier, whether data packets associated with the connection include a cyclic redundancy check, and whether data packets associated with the connection include encrypted information. These technologies can include constructing, based on the connection information, a media access control (MAC) protocol data unit (PDU) that includes a header at a beginning portion of the MAC PDU. The header can include one or more of: a first flag that indicates a header type, a second flag that indicates whether there is a subheader inclusion following the header in the MAC PDU, a flow identifier that, together with the station identifier, identifies the connection, and a length value.