In this work a Multi-Frame Neighbor Discovery Protocol in DTNs over a RFID devices is proposed. Our approach, which is based on a Sift-distribution (we named it s-Persistent) function, takes Single-Frame and Multi-Frame scenarios into consideration. Our s-Persistent approach is applied in a simulated test and in a real test-bed in order to see the effectiveness of the proposal in comparison with a well-known technique such as p-Persistent protocol. Therefore Performance Evaluation has been considered in terms of number of discovered neighbors under different numbers of nodes and frames, moreover we regarded an intra-frame time evaluation. Obtained results show that our solution performs better than p-Persistent, increasing the number of discovered neighbors with better results in intra-frame time evolution.