I experience cross talk in my network for the calls between GSM and PSTN. I made sure that none of the BCCH frequency is same for any cells in my network, BSIC is not identical in order to avoid any problems due to RF. Please can anybody advice me what can be the problem for this to happen.
Check if your circuit has an echo suppressor – very common for internation circuits.
For early deployments of GSM / PSTN, echo was an issue. Later solutions used Echo Cancellers (EC) in pool. The signalling and the selection of a route to the PSTN determined if an EC resource was required. Later solutions could address NEXT, FEXT and Mobile Cross Talk (XT).