The effect of data-link layer reliability on performance of wireless channels

Wireless channels are characterized by time-varying characteristics that often lead to incorrect reception of protocol data units. Automatic repeat request and forward error correction try to prevent it providing reliable service to higher layers. Most models proposed to date assumed that ARQ is fully reliable meaning that a frame is successfully transmitted irrespective of time it takes. In this paper we study the effect of ARQ reliability on performance experienced at higher layers. We propose a model for semi-reliable ARQ operation when a certain frame can be lost due to excessive amount of retransmissions. We also take into account IP packet losses due to limited buffer space. Using numerical results we show that the effect of maximum number of retransmissions depends on channel characteristics and other protocolspsila parameters. Dynamic tuning of this parameter might be beneficial for optimized performance of wireless channels.