A TCP connection over uplink UMTS radio access bearer in RLC acknowledged mode

Integration of cellular networks into the existing Internet world gives rise to some problems, mainly for the reason that protocol mechanisms defined and optimized for wired networks do not perform well when they are directly applied in wireless networks. In this paper we study an uplink TCP connection over the UMTS radio interface, when using a RLC entity in acknowledged mode. We suggest the introduction between TCP and RLC protocols of a specific mechanism called early error notification. Via this mechanism, a TCP sender is informed whenever a data segment is virtually discarded at the RLC level. Thus, a TCP sender detects in advance a segment loss at the RLC level without waiting for three duplicated acknowledgments or a timeout event.