The IFIP TC-6 9th International Conference on Personal Wireless Communi- tions, PWC 2004 is the main conference of the IFIP Working Group 6. 8, Mobile and Wireless Communications. The ?eld of personal wireless communications is steadily growing in imp- tance,fromanacademic,industrialandsocietalpointofview. Thedroppingcost of WLAN and short-range technologies such as Bluetooth and Zigbee is causing the proliferation of personal devices and appliances equipped with radio int- faces. Together with the gradual deployment of powerful wireless infrastructure networks, such as 3G cellular systems and WLAN hotspots, the conditions are being created for a?ordable ubiquitous communication involving virtually any artifact. This enables new application areas such as ambient intelligence where a world of devices, sensors and actuators surrounding us use wireless technology to create systems that assist us in an unobtrusive way. It also allows the - velopment of personal and personalized environments that accompany a person whereverheorshegoes. ExamplesarePersonalAreaNetworks(PAN)physically surrounding a person, and personal networks with a potentially global reach. PWC 2004 re?ects these developments, which are happening on a global scale. Researchers from all over the world, and in particular a large number from Asia, made contributions to the conference. There were 100 submissions. After a thorough reviewing process, 25 full papers and 13 short papers were retained for presentation in the technical sessions. The papers cover the whole range of wireless and mobile technologies: cellular systems, WLAN, ad hoc and sensor networks, host and network mobility, transport protocols for wireless systems, and the physical layer.