FRAMES multiple access for UMTS and IMT-2000

This article presents the FRAMES multiple access (FMA) concept designed for third-generation mobile radio systems. The concept consists of two modes, TDMA-based FMA1 and CDMA-based FMA2, which have contributed to the standardization processes of third-generation systems. FMA1 uses the TDMA slot structure where spreading can be applied inside the slot or, alternatively, plain TDMA-type transmission can be used. FMA2 is a single-carrier wideband CDMA solution using a 4.096 Mchips/s basic chip rate. The FMA concept facilitates common upper-layer protocol structure as well as GSM backwards compatibility for evolution from second-generation systems to third-generation mobile radio systems. The defined concept fulfils the UMTS/IMT-2000 requirements in providing the services needed for the next millennium.