A method for transmitting a data unit (700, 830, 850, 930, 950) in a wireless communication network, the method comprising: generating a physical layer, PHY, preamble; generating a media access control layer, MAC, header, including generating a first address field (754, 756) to include a first address, wherein the first address field indicates one of (i) a communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended, or (ii) a communication device (14, 25) that is transmitting the data unit, generating a second address field (754, 756, 758) to include a second address, wherein the second address field indicates the other one of (i) the communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended, or (ii) the communication device (14, 25) that is transmitting the data unit (700, 830, 850, 930, 950), including the first address field (754, 756) and the second address field (754, 756, 758) in the MAC header; generating the data unit (700, 830, 850, 930, 950) to include the PHY preamble, the MAC header, and a frame check sequence field (806, 906) generated using the MAC header; and causing the data unit (700, 830, 850, 930, 950) to be transmitted, wherein each of the communication devices (14, 25) is adapted to be identified by a respective globally unique address (808, 908), and wherein at least one of the first and second address in the MAC header of the data unit replaces, as compared to a prior art MAC header, the globally unique address of the identified communication device by a shorter address that is not globally unique; characterized by generating the frame check sequence field (806, 906) using a third address (808, 908) that (i) is globally unique and (ii) identifies the communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended; and by generating the data unit to omit the third address (808, 908). generating a physical layer, PHY, preamble; generating a media access control layer, MAC, header, including generating a first address field (754, 756) to include a first address, wherein the first address field indicates one of (i) a communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended, or (ii) a communication device (14, 25) that is transmitting the data unit, generating a second address field (754, 756, 758) to include a second address, wherein the second address field indicates the other one of (i) the communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended, or (ii) the communication device (14, 25) that is transmitting the data unit (700, 830, 850, 930, 950), including the first address field (754, 756) and the second address field (754, 756, 758) in the MAC header; generating a first address field (754, 756) to include a first address, wherein the first address field indicates one of (i) a communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended, or (ii) a communication device (14, 25) that is transmitting the data unit, generating a second address field (754, 756, 758) to include a second address, wherein the second address field indicates the other one of (i) the communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended, or (ii) the communication device (14, 25) that is transmitting the data unit (700, 830, 850, 930, 950), including the first address field (754, 756) and the second address field (754, 756, 758) in the MAC header; generating the data unit (700, 830, 850, 930, 950) to include the PHY preamble, the MAC header, and a frame check sequence field (806, 906) generated using the MAC header; and causing the data unit (700, 830, 850, 930, 950) to be transmitted, wherein each of the communication devices (14, 25) is adapted to be identified by a respective globally unique address (808, 908), and wherein at least one of the first and second address in the MAC header of the data unit replaces, as compared to a prior art MAC header, the globally unique address of the identified communication device by a shorter address that is not globally unique; characterized by generating the frame check sequence field (806, 906) using a third address (808, 908) that (i) is globally unique and (ii) identifies the communication device (14, 25) for which the data unit (700, 830, 850, 930, 950) is intended; and by generating the data unit to omit the third address (808, 908).