The neighborhood discovery and its maintenance are very important in wireless networks for any applications, especially for routing and every self-∗ algorithm. Neighbor nodes are usually discovered thanks to the use of the HELLO protocol. This makes this HELLO protocol very important for wireless networks especially for selforganizing the network. Most of layer-3 protocols assume an ideal MAC layer. In such a case, HELLO protocol parameters have no impact over the self-organization. But this is not the case when considering realistic MAC and physical layers. In this paper, we investigate the impact of the parameters of such a protocol over a self-organization structure when considering realistic a MAC layer. We analyze theoretically and by simulations, the joint effect of the HELLO protocol parameters and of the MAC layer characteristics over several network self-organizations. Categories and Subject Descriptors C.2.1 [Computer-Communication Networks]: Wireless communication General...