The present invention relates to identifying resources allocated in a cellular network for a mobile station for packet-switched services. A first identifier is used for identifying a mobile station, and a second identifier is used for identifying resources allocated for packet-switched services for the mobile station. When a mobile station is entering or has entered a second cell from a first cell, a value of a first type for the second identifier is determined. The first type of the second identifier is for use in both the first cell and the second cell for transmitting packet-switched data between the cellular network and the mobile station.