In order to provide increasing data rates demanded by the consumer market, the 4G RF cellular front-end is becoming increasingly complex with numerous transmit and receive bands, the possibility of multiple antennas and new architectures which involves Uplink and Downlink carrier aggregation. Such new architectures present extreme challenges for conventional fixed band systems composed of PAs, switches and filters. Tunable technologies using RFCMOS SOI technology on high resistivity substrates are already being deployed in increasing numbers in today's advanced RF cellular handsets. This paper will present a discussion on RF topologies and architectures enabled by modern RFSOI technologies to solve the increasingly complex 4G RF front-end, including a discussion of the critical specifications needed in this application space.