EDGE Phase 2 Evolution of EGPRS for Supporting 3G Real-timeServicesKrishna Balachandran, Cristian Demetrescu, Richard Ejzak, Sanjiv Nanda, Hong XieLucent Technologies1Introduction and ScopeGeneral Packet Radio Service (GPRS) was introduced by ETSI to meet the ever-increasing demand for wirelessdata over GSM radio interface. The Enhanced GPRS (EGPRS Phase 1) was later introduced to increase the spectrum efficiency and data throughput by using higher modulation scheme and link adaptation techniques.While (E)GPRS uses packet-switched technology to efficiently transmit best-effort data, the real-time services(e.g. voice) are still supported via the circuit-switched systems. This service separation reduces the potential spectrum efficiency gain resulting from multiplexing different services on the same radio channel.This paper describes the key new concepts needed to introduce statistical multiplexing of all bearer classes onthe GERAN air interface for delivery over the packet-switched network in R2001. It focuses only on the supportof overall UMTS service requirements as described in [1], and does not address network architecture issues orcircuit-switched services.The central new service requirement for GERAN (compared to EGPRS Phase 1) is the support of real-time speech service using the packet-switched backbone network. The focus of the document is the definition of new trafficand control channels to support statistical multiplexing of speech, real-time data, and non-real-time data, and the corresponding new MAC procedures that are needed to guarantee QoS.2List of AcronymsAMR Adaptive Multi-Rate PCCCH Packet Common Control ChannelARI Access Request Identifier PDCP Packet Data Convergence ProtocolBCCH Broadcast Control Channel PH PhaseBEP Bit Error Probability QoS Quality of ServiceBFACCH Burst-based FACCH RAB Radio Access BearerCCCH Common Control Channel RAN Radio Access NetworkCID Carrier Identifier RDC Reassign Downlink ControlCTS Carrier Time Slot RDT Reassign Downlink TrafficDBMCH Downlink Block Message Channel RLC Radio Link ControlDFACCH Dim-and-Burst FACCH RR Radio Resource ManagementDMT Downlink (Burst) Message Type RRBP Relative Reserved Burst PeriodDPRCH Downlink Periodic Reservation Channel RT Real TimeDTCH/FS Downlink Traffic Channel for Full Rate Speech RTP Real Time ProtocolDTCH/HS Downlink Traffic Channel for Half Rate Speech RUC Reassign Uplink ControlDTCH/FD Downlink Traffic Channel for Full Rate Data RUT Reassign Uplink TrafficDTCH/HD Downlink Traffic Channel for Half Rate Data SACCH Slow Associated Control ChannelEDT End Downlink Traffic SD Start DelayEEP Equal Error Protection SDT Start Downlink TrafficEGPRS Enhanced General Packet Radio Service SID Silence DescriptorEUT End Uplink Traffic SUT Start Uplink TrafficFACCH Fast Associated Control Channel TBF Temporary Block FlowFACKCH Fast Acknowledgment Channel TBFI Temporary Block Flow IdentifierFASSCH Fast Assignment Channel TCP Transport Control ProtocolFFS For Further Study TFI Temporary Flow IdentifierFR Full-Rate TS Time SlotFRACH Fast Random Access Channel UDP User Datagram ProtocolGERAN GSM/EDGE Radio Access Network UEP Unequal Error ProtectionHR Half-Rate UBMCH Uplink Block Message ChannelIP Internet Protocol UPRCH Uplink Periodic Reservation ChannelL1Layer 1 (Physical Layer)UMT Uplink (Burst) Message TypeMAC Medium Access Control UMTS Universal Mobile Telecommunications Syste MCS Modulation and Coding Scheme USF Uplink State FlagMR Measurement Report UTCH/FS Uplink Traffic Channel for Full Rate SpeechMS Mobile Station UTCH/HS Uplink Traffic Channel for Half Rate Speech MSACCH Modified Slow Associated Control Channel UTCH/FD Uplink Traffic Channel for Full Rate DataNRT Non-Real Time UTCH/HD Uplink Traffic Channel for Half Rate DataOFF Offset in Frames UTRAN UMTS Terrestrial Radio Access Network PBCCH Packet Broadcast Control Channel VAD Voice Activity Detection1(13)

EDGE Phase 2 Evolution of EGPRS for Supporting 3G Real-time Services