This paper proposes a data transfer protocol called Logical Airlink Control Procedure for Packet Radio Systems (LAPPR) which offers a high throughput efficiency in fading channels. Two main ideas are presented in the flow control and retransmission control methods. A new flow control scheme called "P/F Sliding Flow" is proposed where a high channel utilization rate is provided by continuously transmitting the data frames. At that time, the acknowledgements for the data frames are reduced so as not to occupy both the forward and reverse channels and data exchange between different transmitter-receiver pairs is enabled. A retransmission control scheme called "Recovery Confirming Retransmission Control" is also proposed which makes conventional Automatic Repeat Request (ARQ) schemes significantly more effective in the fading environments by continuously sending the same frame. Computer simulations were carried out and the result showed that a throughput higher than conventional protocols can be achieved.