Synchronization between a transmitter and a receiver with respect to the boundary of higher-layer logical data structures is improved by considering both the statistical likelihood of the value of a transmitted boundary indicator and the quality of the channel during the transmission. A boundary indicator received under poor channel quality, that is decoded to a statistically unlikely value, is suspect and one or more retransmission is requested. A reliable value of the boundary indicator is a retransmitted boundary indicator received during good channel conditions; the value of two boundary indicators received successively, both under poor channel conditions, that decode to the same value; or a majority vote of three successive boundary indicators, the first two received under poor channel conditions. The accuracy of the received boundary indicator is increased, at a cost of one, or at most, two, retransmissions.