Mac layer packet data units for wireless communications

A system for wireless communications, comprising:

• multiple base stations to provide wireless communications to wireless devices, each base station configured to:
• communicate connection information that specifies one or more parameters of a connection between a base station and a wireless device, the connection information indicative of (i) a station identifier, (ii) whether data packets associated with the connection include a cyclic redundancy check, and (iii) whether data packets associated with the connection include encrypted information;
• construct, 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 comprising:
• (i) a first flag that indicates a header type, (ii) a second flag that indicates whether there is a subheader inclusion following the header in the MAC PDU, (iii) a flow identifier that, together with the station identifier, identifies the connection, and (iv) a length value that indicates a length of the MAC PDU;
• and
• communicate the MAC PDU between to one or more wireless devices.