 Voice Services Flexible Alerting Full Band Frequency Division Duplex Fast Fourier Transform Full Rate Guaranteed Bit Rate Gateway GPRS Support Node Gateway MSC Gap Period General Packet Radio Service Global System for Mobile GTP-C GPRS Tunnel Protocol Control GTP-U GPRS Tunnel Protocol User Globally Unique Temporary Identity Hybrid ARQ HARQ Indicator High Interference Indication Home Location Register VoLTE and ViLTE H-PCRF Home PCRF Half Rate Home Subscriber Server Hypertext Transfer Protocol Initial Address Message Interconnection Border Control Function Incoming Communication Barring IMS Centralized Services Inter-Cell Interference Coordination I-CSCF Interrogating-CSCF Insert-Subscriber-Data-Answer Insert-Subscriber-Data-Request Internet Engineering Task Force initial Filter Criteria Inverse Fast Fourier Transform Integrity Key IMS Private User Identity IMS Public User Identity IP Multimedia Routing Number IP Multimedia Sub-system IMS-GWF IMS Gateway Function International Mobile Subscriber Identity Interference Overload Indication Internet Protocol IPBCP IP Bearer Control Protocol IPSec IP Security IP-SM-GW IP Short Message Gateway List of Abbreviations Internet Protocol eXchange IMS Service Control IMS Services Identity Module ISDN User Part IWMSC Inter Working MSC Location Area Identifier Logical Channel Identifier Location-Info-Answer Location-Info-Request Location Retrieval Function Long Term Evolution Multimedia-Auth-Answer Media Access Control Multimedia-Auth-Request Maximum Bit Rate MBSFN RS MBMS Single Frequency Network RS Mobile Country Code Multicast Control Channel Multicast Channel Malicious Communication Identification Media Gateway Control Function Multimedia Gateway Master Information Block Multiple Input Multiple Output Multiple Input Single Output VoLTE and ViLTE Mobility Management Entity Mobile Network Code Main Profile Multimedia Resource Function MRF Controller MRF Processor Mobile-services Switching Centre MDISDN Mobile Subscriber ISDN Number Multicast Traffic Channel Message Waiting I