3G Overview【荐】.ppt

Overview of 3G Why 3G? Higher bandwidth enables a range of new applications!! For the consumer Video streaming, TV broadcast Video calls, video clips – news, music, sports Enhanced gaming, chat, location services… For business High speed teleworking / VPN access Sales force automation Video conferencing Real-time financial information 3G services in Asia CDMA (1xEV-DO) Korea: SKT, KTF Japan: AU (KDDI) WCDMA / UMTS Japan: NTT DoCoMo, Vodafone KK Australia: 3 Hutchinson Hong Kong: 3 Hutchinson 3G Standards 3G Standard is created by ITU-T and is called as IMT-2000. The aim of IMT-2000 is to harmonize worldwide 3G systems to provide Global Roaming. GSM evolution to 3G GPRS General Packet Radio Service Packet based Data Network Well suited for non-real time internet usage including retrieval of email, faxes and asymmetric web browsing. Supports multi user network sharing of individual radio channels and time slots. Provides packet network on dedicated GSM radio channels GPRS overlays a packet-switched architecture on existing GSM network architecture Variable performance… Packet Random Access, Packet Switched Content handling Throughput depends on coding scheme, # timeslots etc From ~ 9 kbps min to max. of 171.8 kbps (in theory!) GPRS (contd..) Modulation – GMSK Symbol Rate – 270 ksym/s Modulation bit rate – 270 kbps Radio data rate per time slot – 22.8kbps User data rate per time slot – 20kbps (CS4) User data rate (8 time slots) – 160kbps, 182.4kbps Applications are required to provide their own error correction scheme as part of carried data payload. EDGE EDGE Enhanced Data Rates for Global Evolution EDGE is add-on to GPRS Uses 8-PSK modulation in good conditions Increase throughput by 3x (8-PSK – 3 bits/symbol vs GMSK 1 bit/symbol) Offer data rates of 384kbps, theoretically up to 473.6kbps Uses 9 Modulation coding schemes (MCS1-9) MCS(1-4) uses GMSK, while MCS(5-9) uses 8PSK modulation. Uses Link adaptation algorithm Modulation Bit rate – 810kbps Radio data