A packet network employs frame aggregation to reduce the number of physical-layer frames employed to transfer a given amount of user data. A packet network might employ physical (PHY) and medium access control (MAC) layers of a wireless local area network (WLAN) operating in accordance with one or more IEEE 802.11 standards. Frame aggregation combines several separate, higher-layer frames with user data into one PHY-layer frame, thus increasing the amount of user data per PHY-layer frame transmitted. Frame aggregation improves the efficiency by reducing both PHY-layer overhead and MAC-layer overhead.