Abstract: The invention relates to handling of an acknowledgement message related to packet data transmission, said acknowledgement message acknowledging positively or negatively one or more data blocks sent from a terminal and said acknowledgement message comprising an information element related to the acknowledgement which element conditionally comprises a length field L, which indicates the length of the value part of said information element and possibly an uncompressed Ack/Nack bit map of varying length, which bit map length Lu may be calculated from the value of L with a predetermined calculation formula. In the method, one receives an acknowledgement message comprising said information element from a data transmission network and automatically ignores an uncompressed Ack/Nack bit map possibly included in the acknowledgement message, if said length field L is unspecified from the viewpoint of the terminal.

Abstract: The invention relates to handling of an acknowledgement message related to packet data transmission, said acknowledgement message acknowledging positively or negatively one or more data blocks sent from a terminal and said acknowledgement message comprising an information element related to the acknowledgement which element conditionally comprises a length field L, which indicates the length of the value part of said information element and possibly an uncompressed Ack/Nack bit map of varying length, which bit map length Lu may be calculated from the value of L with a predetermined calculation formula. In the method, one receives an acknowledgement message comprising said information element from a data transmission network and automatically ignores an uncompressed Ack/Nack bit map possibly included in the acknowledgement message, if said length field L is unspecified from the viewpoint of the terminal.