Mobile communication system, SGW, incoming method of mobile communication system, and incoming method of SGW

摘要

A mobile communication system according to the present invention includes a UE (45), an MME (25), an SGSN (27), and an SGW (15). When the ISR is valid in the UE (45), the MME (25), the SGSN (27), and the SGW (15), the SGW (15) transmits Downlink Data Notification Message, and receives a Modify Bearer Request message from another MME (35) or another SGSN (37) different from the MME (25) and the SGSN (27), it transmits another Modify Bearer Request message And means for retransmitting Downlink Data Notification only to the MME (35) or other SGSN (37).