Patent ID: 9609545
Date: 2017-03-28
CPC Classifications: H04L,H04W

Claim:
1. A communication system including a second communication device which sends data to a first communication device, and also including a third communication device which sends data to said second communication device, and also corresponding to PDCP (Packet Data Convergence Protocol), the communication system comprising: a buffer unit which is provided in said second communication device comprising a processor and temporarily stores the data sent from said third communication device for the purpose of sending the data to said first communication device; a data measurement unit which is executed by the processor in said second communication device and measures the volume of the data stored in said buffer unit; a sending data storage unit which is provided in said third communication device and stores the data to be sent to said second communication device; a transmission unit which is provided in said third communication device and sends the data stored in said sending data storage unit to said second communication device; and a congestion state determination unit which is executed by the processor in said second communication device and, on the basis of a measurement value of said data volume measured by said data measurement unit, determines whether or not said buffer unit is in a congestion state, wherein, said second communication device is provided with a congestion state notification unit, executed by the processor, which, when said congestion state determination unit has determined that said buffer unit is in a congestion state, notifies said third communication device of said buffer unit being in the congestion state, as congestion state information, by putting the information on a new message or a new parameter of the S1 Application protocol (S1-AP) or the GPRS Tunneling Protocol for User Plane (GTP-u), and wherein, said transmission unit sends the data stored in said sending data storage unit to said second communication device, on the basis of said congestion state information sent by said congestion state notification unit.