Network controller and communication system for performing packet data transfer with reduced delay

摘要

In a communication system (SYS) in which a packet data transfer is performed between a network side (NS) and a subscriber terminal side (SS) a physical connection (PC) is maintained during the data packet transfer. In association with each transferred data packet (DP) a transmitter queue length information (CV) is transmitted to a network controller (NC) on the network side (NS). On the basis of the received length information (CV) a network side transmission resources controller (SCH-RES) determines transmission resources (TS) for the data packet transfer on the uplink connection (UL) in the next uplink frame such that at least one data packet (DP) remains in the subscriber terminal side transmitter buffer queue (TR-QUE) during an active period of the application. Since at least one data packet is always present in the transmitter queue (TR-QUE) unnecessary physical connection releases can be avoided. In addition to adjusting the transmission resources on the basis of the received length information, the controller (SHC-RES) can also estimate the arrival rate of data packets in the transmitter queue (TR-QUE) and can make the assignment of resources dependent on the determined arrival rate (AR). The invention finds particular application in the GPRS/(E)GPRS/GSM environment.