Our paper explores the issue of how to provide appropriate quality of Service mechanisms closely integrated with flexible mobility management in wireless local area networks. We consider them as access networks of choice for the high performance Wireless Mobile Internet. We present a hierarchical QoS architecture that extends Differentiated Services (DiffServ) to mobile hosts in a wireless environment. Our approach is based on controlling several parameters of a wireless LAN cell: the limited geographicaL span to ensure the same high bit rate for all hosts, the constrained rate of traffic sources to limit the use of the channel in function of the required QoS and the limited number of active hosts to keep the load sufficiently low. The QoS management is coupled with mobility management at the IP level. We use a micro-mobility scheme implemented in the IPv6 layer with fast hand-offs between adjacent cells. Micro-mobility avoids address translation, traffic tunnelling, and enables fast hand-offs. We give some details of experiments to show the quality of service differentiation over the 802.11b network.