Mobile Generations 1st generation systems, analog ? NMT, AMPS, TACS 2nd generation systems, digital ? GSM, IS-136 TDMA, IS-95 CDMA, PDC 3rd generation systems, digital wide band ? WCDMA standards have been prepared by ETSI (Europe), ARIB (Japan), TIA (USA),... ? 3GPP1 is a joint project that combines all proposals into one standard ? HARMonized standard includes three modes ? Direct sequence mode based on 3GPP (UTRA2/FDD) ? Multi carrier mode based on CDMA2000 (USA proposal) ? TDD mode based on 3GPP (UTRA/TDD)