Confusion background from compact binaries

Double neutron stars are one of the most promizing sources for terrestrial gravitational wave interferometers. For actual interferometers and their planned upgrades, the probability of having a signal present in the data is small, but as the sensitivity improves, the detection rate increases and the waveforms may start to overlap, creating a confusion background, ultimately limiting the capabilities of future detectors. The third generation Einstein Telescope, with an horizon of $z>1$ and very low frequency ``seismic wall’’ may be affected by such confusion noise. At a minimum, careful data analysis will be require to separate signals which will appear confused. This result should be borne in mind when designing highly advanced future instruments.