In this paper, we propose a new mechanism to establish stable and sustainable paths between all pairs of nodes in a Mobile Ad hoc Network. In this mechanism, we use a stability function as the main path selection criterion based on the calculation of the mobility degree of a node relative to its neighbor. We applied this mechanism on the OLSR protocol (Optimized Link State Routing Protocol) to elect stable and sustainable MPR (Multipoint relays) nodes and topology. This mechanism significantly minimizes the recalculation of MPR and the routing tables recalculation process. Moreover, it guarantees other QoS (Quality of Service) metrics such as the packet loss and the response time. The simulation results show the effectiveness of our mechanism and encourage further investigations to extend it in order to guarantee other QoS requirements.