Communication system

A control method of a communication system including a base station that communicates with the terminal by radio transmission, a server that provides services to the terminal, a proxy device that controls communications between the base station and the server and a control device that obtains information for determining whether communications that the base station accommodates are congested, the method comprising:

• determining, by the control device, whether communications that the base station accommodates are congested, based on the obtained information;
• identifying, by the control device, a terminal accommodated in the base station in which communications are determined to be congested, as a terminal of which communications the proxy device is to control;
• controlling, by the proxy device, communications between the base station and the server, by using a protocol that acknowledges that the data has reached a reception side;
• calculating, by the proxy device, a loss rate at which communications by the identified terminal are to be discarded, by utilizing acknowledgement packets that used in the protocol;
• relaying, by the proxy device, a communication of the identified terminal, by a transmission band from which a portion of the calculated loss rate has been reduced;
• obtaining, by the proxy device using the protocol, snd as the number of transmitted packets, ack as the number of acknowledgement packets that indicate that the transmitted packets has reached the reception side, its as the number of packets of which retransmission has been requested, and sack.dup as the number of selective response packets when a value held by the acknowledgement packets is the same as a value held by selective response packets received immediately before, in the selective response packets that follow the acknowledgement packet and also that indicates a start end and a terminal end of a discontinuous portion of packets at the reception side, and
• calculating, by the proxy device, rts/snd as the loss rate when snd >ack+rts, and
• calculating, by the proxy device, 1−(ack−sack.dup)/snd as the loss rate when snd <=ack+rts.

A proxy device provided in a communication system including a base station that communicates with the terminal by radio transmission, a server that provides services to the terminal, and a control device that obtains information for determining whether communications which the base station accommodates are congested, and identifies a terminal that is accommodated in the base station in which it is determined that the communications are congested, as a terminal of which communications the proxy device is to control, the proxy device comprising:

• a memory storing one or more programs;
• and
• a processor that operates in accordance with the programs;
• wherein the processor is configured to
• control communications between the base station and the server, by using a protocol that acknowledges that the data has reached a reception side,
• calculate a loss rate at which communications by the identified terminal are to be discarded, by utilizing acknowledgement packets which are used by the protocol,
• relay a communication of the identified terminal, by a transmission band which has been reduced by the calculated loss rate portion,
• obtain, by using the protocol, snd as the number of transmitted packets, ack as the number of acknowledgement packets that indicate that the transmitted packets has reached the reception side, rts as the number of packets of which retransmission has been requested, and sack.dup as the number of selective response packets when a value held by the acknowledgement packets is the same as a value held by selective response packets received immediately before, in the selective response packets that follow the acknowledgement packet and also that indicates a start end and a terminal end of a discontinuous portion of packets at the reception side, and
• calculate rts/snd as the loss rate when snd >ack+rts, and
• calculate 1−(ack−sack.dup)/snd as the loss rate when snd <=ack+rts.