The fourth Generation Wireless Network represents the next generation of mobile networks. These networks include ad-hoc networks that are characterized as autonomous and independent of any existing infrastructure. One of the major problems of these networks is the security of data and equipment. Data should be confidential, and the equipments should also be protected for saving energy, or for isolation of a congestioned node, etc. In this study we propose a new protocol SERAN (Security Equipment protocol in Routing in Ad hoc Networks), which permits to hide an equipment in ad hoc networks.