Mobilné systémy 3. generácie UMTS Ing. Matúš Turcsány, PhD. turcsany@ktl.elf.stuba.sk KTL FEI STU 2009
Prehľad prednášok UMTS HSDPA, EUL HSPA evolution LTE LTE-Advanced
Nasadené technológie GSM worldwide (~ 720 networks) EDGE almost worldwide (~ 300 networks) UMTS (~ 300 networks) HSDPA (~ 290 networks) EUL (~ 90 networks) 3GPP CDMA2000 (~ 250 networks) EV-DO Rel.0 (~ 90 networks) EV-DO Rev.A (~ 10 networks) 3GPP2 FLASH-OFDM USA, Slovakia proprietary Mobile WiMAX South Korea (WiBro) Sprint (2008) IEEE 802.16
Dnešné možnosti GSM/GPRS/EDGE mainly voice oriented service downlink up to 300 kbps uplink up to 200 kbps FLASH-OFDM pure IP architecture DL up to 5,3 Mbps UL up to 1,8 Mbps UMTS/HSDPA/EUL higher voice capacity UMTS DL/UL 384 kbps HSDPA up to 28 Mbps EUL up to 5,8 Mbps CDMA2000 EV-DO packet services only DL up to 3,1 Mbps UL up to 1,8 Mbps WiBro / Mobile WiMAX packet services only DL up to 3 / 10 Mbps UL up to 1,2 / 2,5 Mbps
Prečo UMTS?
Prečo UMTS?
Prečo UMTS?
Evolúcia štandardov 3GPP GSM GPRS EDGE UMTS HSDPA EUL LTE 3GPP2 IS-95 CDMA2000 EV-DO rel.0 EV-DO rev.a UMB IEEE FLASH-OFDM 802.16a (WiMAX) 802.16e (Mobile WiMAX)
Evolúcia štandardov Voice evo EDGE Evo GSM GPRS EDGE UMTS HSDPA EUL LTE HSPA+ LTE-Advanced
IMT-2000
3GPP
3GPP spec. list www.3gpp.org
Internet Architektúra GGSN HLR VLR AuC EIR MSC GMSC PSTN SGSN IuCS GSM BSC BTS UMTS RNC Node B IuPS RNC Iur RNC MS UE IuB UTRAN Node B
Roadmap 3GPP releases Rel.99/4 Rel.5 Rel.6 Rel.7 Rel.8 Rel.9 WCDMA HSDPA EUL HSPA+ HSPA+ HSPA+ QPSK 16QAM multi code MIMO, 64QAM, 16QAM UL DC Comb DL Mbit/s 0.384 14.4 14 28 42 168 UL Mbit/s 0.384 0.384 5.8 12 12 24 Latency (ms) ~150 ~75 ~50 ~30 ~30 ~30 LTE
3G voice or data? Relative Network Load RNC level 15 13 11 9 7 5 3 1 2 6 9 4 8 2 6 6 4 8 2 6 3 4 8 2 6 128 HSDPA networks 50% at 3,6 Mbps marginal 7,2 Mbps share 310 HSDPA devices 221 HSPA networks > 30% at 7,2 Mbps 55 EUL networks 800 HSPA devices Packet data Voice Jan 07 Mar 07 May 07 Jul 07 Sep 07 Nov 07 Jan 08 Mar 08 May 08 July 08 Sep 08 Nov 08 Jan 09 Data is surpassing voice on 3G since 2 years
Rádiová prístupová sieť- UTRAN Komponenty Node B RNC Multiplexná technika CDMA Duplexný mód FDD TDD
Funkcie Node B Air interface Transmission / Reception Modulation / Demodulation CDMA Physical Channel coding Micro Diversity (Soft Handover) Error Handling Closed loop power control
Funkcie RNC Radio Resource Control Admission Control Channel Allocation Power Control Settings Handover Control Macro Diversity (Soft Handover) Ciphering Segmentation / Reassembly Broadcast Signaling Open Loop Power Control
Duplexný mód Frequency division duplex + symetric traffic (e.g. voice) + higher average power => less Node Bs - higher complexity (HW) - channel measurements must be reported FDD Time division duplex + asymetric traffic (data) + channel measurements are precise - lower average power - strict synchronization needed - higher delays TDD
CDMA Interference limited system Sequences selection is crucial Power control needed Soft handover possible 5 MHz channel 3,84 Mchip/s
Soft handover
Importance of Soft Handover Graphs show probability of excessive interference in neighbouring cell Active set size of 4 was agreed as mandatory for UEs
Why power control? NEAR FAR effect High interference between users & cell breathing
Power control Choose throughput Evaluate radio conditions Required cell power Circuit switched services are guaranteed Packet switched services are best effort
Power control Open loop initial access to the network Closed loop INNER loop Guarantee link quality (keep desired SIR) 1500 times per second (Hz) OUTER loop Minimize transmit power by setting SIR target for inner loop Estimate SIR target based on BLER
Air interface protocol model
Channel concept new for UMTS, not in GSM/GPRS what type of data BCCH, PCCH, DCCH, CCCH, DTCH, CTCH, how and with which type of characteristics BCH, PCH, RACH, FACH, DSCH, HS-DSCH, DCH, SCH, CPICH, PDSCH, HS-PDSCH, DPDCH, DPCCH, PRACH, define the exact physical characteristics
Logical channels Control channels Common (P2M) Dedicated (P2P) Traffic channels Common Dedicated
Transport channels Common channels Dedicated channel DCH (UL & DL)
Physical channels Synchronization Pilot Paging Dedicated Physical Data Channel Dedicated Physical Control Channel High Speed Physical Downlink Shared Channel
Channels downlink uplink
Channel structure - UL
Channel structure - UL
Channel structure - DL
Channel structure - DL
Fyzickávrstva-DL
Channel Coding
Fyzickávrstva-DL
Spreading - UL
Modulation - UL () ( ) ( ) + + = 2 0 4 1 1 cos 4 1 sin C C C C C T t T t T t T t T t t RC α π α π α α π root-raised cosine (RRC) with roll-off α =0.22
RRCF impulse response 1.2 1 1 1 1 0.8 0.6 RRCF() t 0.4 0.2 0 0 0.2 0.4 6 4 2 0 2 4 t normalized Tc = 1 (Tc = 26,042 μs)
Spreading - DL
Modulation - DL () ( ) ( ) + + = 2 0 4 1 1 cos 4 1 sin C C C C C T t T t T t T t T t t RC α π α π α α π root-raised cosine (RRC) with roll-off α =0.22
Codes
OVSF
Scrambling codes - UL (long code)
Scrambling - DL
Spreading & scrambling
Received signal
Detection I = number of fingers of RAKE receiver
Measurements
Limiting factors Downlink is power limited max Node B power Dedicated channels Common channels Uplink is interference limited max noise level Intracell interference Intercell interference
Power dynamics 100 ms P nom P CCH
Services & RABs
Services & RABs New service: Video Call RAB type CS voice CS video call CS Streaming PS Best Effort Rate [kbps] 12,2 64 57 64/128/384