Patent ID: 7466708

Claim:
A method of operating a mobile radio network in which user data is transmitted from a first network entity to a second network entity of the mobile radio network, the method comprising: combining the user data into at least one packet data unit in a first convergence protocol layer protocol unit of the first network entity; transmitting the at least one packet data unit from a first radio link control layer protocol unit of the first network entity to a second radio link control layer protocol unit of the second network entity; transmitting an error message, if there is a transmission failure of the at least one packet data unit, by the first radio link control layer protocol unit to the first convergence protocol layer protocol unit after receiving a confirmation message confirming the transmission failure from the second radio link control layer protocol unit, wherein the error message to be transmitted is generated by the first radio link control layer protocol unit; numbering in a sequential manner, in an order of their transmission, a plurality of packet data units to be transmitted by the first convergence protocol layer protocol unit to the second network entity; storing the plurality of packet data units in a memory of the first convergence protocol layer protocol unit; and setting a counter in the first convergence protocol layer protocol unit according to a number of one of the plurality of packet data units about to be transmitted; wherein the transmission failure of the plurality of packet data units and their numbers are communicated by the error message of the first radio link control layer protocol unit, and received by the first convergence protocol layer protocol unit so that the plurality of packet data units assigned to these numbers are deleted from the memory of the first convergence protocol layer protocol unit, the counter is decremented by a number of unsuccessfully transmitted packet data units, and a new packet data unit to be transmitted is numbered as a function of the counter status thus decremented.