Abstract: A transmitting party sends a transfer request to a transfer network. Upon receiving the request, the transfer network allocates a service number (SN) to the transmitting party, if allowed by the current traffic load. The service number identifies the transmitting party for a predetermined period. Upon sending the service number to the communicating party which originated the transfer request, the transfer network preferably starts a timer which monitors the validity period of the service number. The transmitting party sends the destination address (DN) over the transfer network only once during the validity period of the service number. The transfer network associates the destination address (DN) to the service number allocated to the transmitting party. The transmitting party utilizes only the service number (SN) as an identity in the data packets transferred during the actual data transfer, and the transfer network routes the packet to the destination address associated with the service number.

Abstract: Packet data transfer in a digital cellular radio system including at least one common organization channel for sending pages, connection requests, and channel assignments so as to establish an actual connection on another channel. User data is transferred from the mobile stations to the base station interleaved with the connection request messages on at least one random-access-type organization channel in messages which will not result in a normal connection establishment. The mobile station sends a random-access-type packet data transfer request on the random-access-type organization channel. A timing advance corresponding to the distance between the base station and the mobile station is determined on the basis of the request received at the base station.