Network slicing has recently been proposed as one of the main enablers for 5G networks; it is bound to cope with the increasing and heterogeneous performance requirements of these systems. To “slice” a network is to partition a shared physical network into several self-contained logical pieces (slices) that can be tailored to offer different functional or performance requirements. Moreover, a key characteristic of the slicing paradigm is to provide resource isolation as well as an efficient use of resources. In this context, a slice is envisioned as an end-to-end virtual network which permits that the infrastructure operators lease their resources to service providers (tenants) through the dynamic, and on-demand, deployment of slices. Tenants may have complete control over the slice functions and resources, and employ them to satisfy their client’s demands. This paradigm, which changes the way networks have been traditionally managed, was initially proposed for the wired realm (core networks). More recently, several 5G actions from the scientific community and the industry have proposed solutions to integrate slicing to the Radio Access Networks (RANs). However, these works focus on general architectures and frameworks for the management and instantiation of network slices avoiding details on how the slices are implemented and enforced in the wireless devices. Even more, while some techniques for slice enforcement already exist, most of them concentrate on cellular technologies, ignoring WiFi networks. Despite of their growing relevance and ubiquity, there are not many works addressing the challenges that appear when trying to apply slicing techniques over WiFi networks. In this scenario, this thesis contributes to the problem of slicing WiFi networks by proposing a solution to enforce and control slices in WiFi Access Points. The focus of this work is on a particular and complex variant of network slicing called QoS Slicing, in which slices have specific performance requirements. The main thesis contributions are divided in three: (1) a detailed analysis of the network slicing problem in RANs in general and in WiFi in particular, as well as a study and definition of the QoS Slicing problem, (2) a resource allocation model and mechanism for Wifi devices, and (3) a QoS Slicing solution to enforce and control slices with performance requirements in WiFi Access Points.