The fourth study visit was held from May 06-08, 2025, at the UPM – Universidad Politecnica de Madrid, Escuela Técnica Superior de Ingenieros de Telecomunicación (ETSIT), Madrid, Spain. In addition to the hosts, UPM, and the coordinator, AASKM, representatives from partner institutions attended the study visit: VSB-TUO, AATPS, UPKM, FPRN, UMT, UES, SUM, USB, UNIRI RITEH, and LRS. A total of 33 representatives from the institutions participated in the study visit.