HIPERLAN/2 is a recent standard from ETSI for high-speed wireless LANs. This work explores this standard when providing QoS support to different traffic types. We describe a new bandwidth allocation protocol, which distinguishes among five types of connections, each one of them having its own QoS requirements. We carry out a performance evaluation via simulations that reflects the behavior of the novel MAC protocol. The bandwidth allocation protocol is evaluated in terms of its flexibility and efficiency in supporting delay sensitive traffic. We look particularly to MPEG-4 video communications, an application which is expected to be widely deployed in broadband wireless LANs.