Mobile ad hoc networks constitute a popular subject for research as devices and wireless communication technologies are became widespread and ubiquitous. With the expanding range of applications of MANETs, supporting the quality of service (QoS) in these networks is becoming a real need. This paper provides a solution for QoS support taking into account radio interferences. We note that, because of the ad hoc network characteristics, we cannot provide hard QoS guarantees but only a service differentiation between different flow types. This QoS support is based on the OLSR routing protocol and the CBQ scheduling. Simulation results show that flows with QoS requirements receive the requested bandwdth and Best Effort flows share the remaining bandwidth. Moreover, mobility is supported.