TRANSMISSION/RECEPTION SYSTEM AND PROGRAM

PROBLEM TO BE SOLVED: To provide a transmission/reception system and program which can estimate temporal fluctuation in a signal propagating through a transmission cable.SOLUTION: A first transmission/reception device 2 comprises: a control unit 26 which, assuming the strength of a signal received by a receiving unit 22 when a linkage establishment signal is transmitted from a transmission unit 21 via a first signal line 31 while the receiving unit 22 is receiving no linkage establishment signal via a second signal line 32 to be a first value and assuming the strength of a linkage establishment signal received by the receiving unit 22 via the second signal line 32 while no linkage establishment signal is being transmitted from the transmission unit 21 via the first signal line 31 to be a second value, lets an S/N ratio calculation unit 241 calculate an S/N ratio which is derived by dividing the second value by the first value; a jitter estimation unit 243 which estimates a jitter in a signal propagating through a transmission cable 3 connecting between transmission/reception devices 2 and 4 on the basis of the S/N ratio and S/N ratio-to-jitter relationship information 245.