 multiple time slots to IMT-2000 technologies in ITU-R recommendation a user and by modified coding schemes. M.1225. The evaluation criteria set the target data rates Packet data over cellular systems became a reality for the 3G circuit-switched and packet-switched data during the second half of the 1990s, with General Packet services: Radio Services (GPRS) introduced in GSM and packet Up to 2 Mbps in an indoor environment. data also added to other cellular technologies such as the Up to 144 kbps in a pedestrian environment. Japanese PDC standard. These technologies are often re- Up to 64 kbps in a vehicular environment. ferred to as 2.5G. The success of the wireless data service These numbers became the benchmark that all 3G iMode in Japan gave a very clear indication of the potential technologies were compared with. However, already for applications over packet data in mobile systems, in today, data rates well beyond 2 Mbps can be seen in spite of the fairly low data rates supported at the time. deployed 3G systems. With the advent of 3G and the higher-bandwidth radio interface of UTRA (Universal Terrestrial Radio Access) came possibilities for a range of new services that 4.1.1.3 Research on 3G were only hinted at with 2G and 2.5G. The 3G radio access development is today handled in 3GPP. However, In parallel with the widespread deployment and evolu- the initial steps for 3G were taken in the early 1990s, tion of 2G mobile-communication systems during the long before 3GPP was formed. 1990s, substantial efforts were put into 3G research What also set the stage for 3G was the in- activities. In Europe the partially EU-funded project ternationalization of cellular standardization. GSM was Research into Advanced Communications in Europe a pan-European project, but quickly attracted worldwide (RACE) carried out initial 3G research in its first phase. interest when the GSM standard was deployed in 3G in Europe was named Universal Mobile Telecommu- a number of countries outside Europe. There are today nications Servi