Ok I solved. When you configure node with node-config if you want to use a different seed, you firstly have to create an object set p [new Propagation/Shaowing] $p seed heuristic 0
and then to USE -propInstance and not -propType in node-config -- ---------------------- ---------------------- Giuseppe De Marco, Ph.D. SkypeID:giuseppe_dem2 Dipartimento di Ingegneria dell'Informazione e Ingegneria Elettrica DIIIE, University of Salerno via ponte don Melillo 1, Fisciano, Salerno tel: +39 089 964012 email: [EMAIL PROTECTED] Department of Information and Communication Engineering Faculty of Information Engineering Fukuoka Institute of Technology (FIT) 3-30-1 Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295 Japan email: [EMAIL PROTECTED] --------------------