ANNEX II LIST OF ABBREVIATIONS Table 9: List of Abbreviations 2G 2ND Generation 3G 3RD Generation 4G 4TH Generation CDR Call Detail Record CSCF Call Session Control Function CSFB Circuit Switch Fall Back CSR Call Setup Rate CSSR Call Setup Success Rate DNS Domain Name Server DSL Digital Subscriber Line ERAB E-UTRAN Radio Access Network E-UTRAN Evolved UMTS Terrestrial Radio Access Network HTTP HyperText Transfer Protocol IMS IP Multimedia Subsystem LTE Long term evolution MOS Mean Opinion Score MTTR Mean Time To Repair PDP Packet Data Protocol POI Point of Interconnection PS Packet Switch QoS Quality of Service RAB Radio Access Bearer RRC Radio Resource Control RSCP Received Signal Code Power RSRP Reference Signal Received Power RSSI Received Signal Strength Indicator SDCCH Stand-alone Dedicated Control Channel SHO Soft Hand Over SLA Service Level Agreement SMS Short Messaging System 22