A radio access network (RAN) (20) comprise a base station (28) and a wireless terminal (30). The base station 28 comprises a transceiver (38) and a frame handler (40), the wireless terminal (30) comprises a transceiver (48) and a wireless terminal frame handler (50). The frame handlers (40, 50) handle a enhanced frame F having enhanced frame structure. At least a down link portion of the frame is formatted and handled in a manner whereby the frame can be perceived as a first format type of frame if the wireless terminal is a first type of wireless terminal and perceived as an enhanced or second format type of frame if the wireless terminal is a second type of wireless terminal. The frame handler configures the frame as plural sub frames, each sub frame having a down link burst followed by an up link burst. The frame is preferably configured to afford the second type of wireless terminal sufficient time to develop an acknowledgement for a message transmitted in a down link burst, the acknowledgement being sent to the base station in an up link burst which is within one frame length of the message.