Patent ID: 7283511

Claim:
A method of operating a mobile radio network, useful data being transmitted between a mobile unit and a first radio base station, the method comprising: combining the useful data into packet data units prior to a transmission of the packet data units, transmission-specific information relating to the transmission of the packet data units and describing an instantaneous state of the transmission of the packet data units being stored both in the mobile unit and in a first network unit, the first network unit being superordinate to the first radio base station; transmitting the transmission-specific information stored in the first network unit to a second network unit of a second radio base station if a connection change from the first radio base station to the second radio base station occurs, the second network unit being superordinate to the second radio base station, the transmission-specific information being transmitted to continue the transmission of the packet data units after the connection change; prior to the connection change, halting the transmission of the packet data units from the first radio base station to the mobile unit, the transmission of the packet data units being halted by the first network unit; transmitting a first identifier of one of the packet data units expected next from the mobile unit to the second network unit using the transmission-specific information; and transmitting a first connection-change packet data unit from the second network unit to the mobile unit, the first connection-change packet data unit including the first identifier.