This paper gives a topical overview of wireless network security aspects. Security measures taken depend on the different protocols, standards, techniques and systems available. A brief introduction to security protocols, standards and corresponding technologies is given. The essay will concentrate on 2G, 2.5G, 3G and wireless local area networks. Standards, like WAP, IEEE 802.11, HomeRF, HIPERLAN/2, IPSec and Bluetooth, are included. A local area network, MediaPoli, has been implemented to work as a testbed for new innovations, products and services. The development environment is based on this high-capacity wired/wireless broadband network. Key research areas, actual projects and offered services are discussed. All activities aim at the future information society.