S-band SAB/SAP SAE SafetyNET Sampling SART SAW-filter SBR SCA SCH S-DMB SDR SDSL Semi duplex Serial port Set-Top Box SFA SFN SGSN Short Range Device Short Range Radar SIM Simplex SIP Single Frequency Network SMIL SMOS SMS SMS SMS-CB SMSC SNMP Soft handover Software Defined Radio Spectral Band Replication Spectrum Overlay Spectrum Pooling Spectrum Underlay Spider Spread spectrum Spurious emission SRD SRR Star topology STB STiMi