The invention is concerned with the transmission of streaming scalable data, particularly video data, through lossy communication channels, for applications in which limited retransmission is possible, and the associated reception and decoding of transmitted data. The PET (Priority Encoding Transmission) framework is used and the invention exploits both unequal error protection and limited retransmission. Each element in the scalable representation of each frame can be transmitted in one or both of two transmission slots, depending on the availability of the data received from the first of the two transmission slots. An optimization algorithm determines the level of protection which should be assigned to each element in each slot, subject to transmission bandwidth constraints. To balance the protection assigned to elements which are being transmitted for the first time with those which are being retransmitted, the proposed algorithm in preferred embodiments formulates a collection of hypotheses concerning its own behavior in future transmission slots.