This book constitutes the refereed proceedings of the First IFIP TC6 Working Conference on Wireless On-Demand Network Systems, WONS 2004, held in Madonna di Campiglio, Italy in January 2004. The 25 revised full papers presented together with 7 short papers were carefully reviewed and selected from 77 submissions. The papers are organized in topical sections on localization and mobility management; MAC and radio resource management; Bluetooth scatternets; ad-hoc routing; security, applications, and service support; MAC analytical models; and on-demand Internet access.