Patent ID: 8270312

Claim:
A communication system; comprising: a first communication device for transmitting a plurality of packets in different packet sizes; and a second communication device, including: a reception unit for receiving over one or more links packets transmitted from the first communication device, and a calculation unit for calculating a packet loss rate for each packet size based on reception result of the reception unit, wherein a bit error rate during link transmission of the packets is estimated from a difference of the packet sizes of the packets transmitted from the first communication device, as well as from the packet loss rate for each packet size calculated by the calculation unit, according to the relation: BER= 1−( P″ loss −1/ P′ loss −1) 1/L″-L′ , where P′ loss is the loss rate of packets of packet size L′, and P″ loss is the loss rate of packets of packet size L″.