LTE Overview October 6, 2011

Transcription

1 LTE Overview October 6, 2011 Robert Barringer Enterprise Architect AT&T Proprietary (Internal Use Only) Not for use or disclosure outside the AT&T companies except under written agreement

2 LTE Long Term Evolution LTE Is. The 4G Wireless Communications Specification From The 3GPP Only IP Communications A Set Of Enhanced Network Infrastructure Elements in Support of Enhanced Network Features and Controls The Platform For Future Rich-Interactive Multimedia Communications Page 2

3 LTE Path Forward LTE Worldwide Subscribers * Juniper Research Our Approach Consistent with worldwide standards 300M Efficient path to LTE Fallback to faster HSPA Aligned with industry timing, device availability Market Launch underway Fastest overall experience 500,000 First wireless network designed with true Enterprise focus (data) * Reported by CNET, August 2010 Standard Platform for IP Services Communications Enables fast and effective multimedia communications Page 3

4 Smooth Efficient Path to LTE HSPA vs. CDMA Worldwide Ecosystem HSPA Consistent with worldwide standards Efficient path to LTE Fallback to faster HSPA HSDPA UMTS Peak 384 Kbps Peak 3.6 Mbps HSPA 7.2 4G - HSPA+ Peak 7.2 Mbps 4G - LTE Peak 100 Mbps Peak 21 Mbps GPRS EDGE Peak 48 Kbps Peak 237 Kbps 2X to 3X speed advantage Backwards Compatible Present Future CDMA Significant technology shift to LTE Limited device options in early years Fallback to slower EV-DO LTE Technology Shift EV-DO Peak 1.6 Mbps CDMA Peak 14.4 kbps 4 Based on theoretical peak speeds. Actual speed experienced will be less. *Based on HSPA 7.2 theoretical max

5 LTE Performance Specifications (3GPP TR ) Throughput (in Mbps) DOWNLINK 5 MHz 10 MHz 20 MHz 2x2 MIMO x4 MIMO UPLINK 2Rx,1Tx 5 MHz 10 MHz 20 MHz 16 QAM QAM Average download 5-12 Mbps, upload 2-5 Mbps 5 UE Categories (Cat 3: 100/50 peak) Latency Latency of less than 10 ms in unloaded condition Dormant to active state transition time of less than 50 ms. Mobility Higher mobile speed between 15 and 120 km/h supported with high performance. Mobility across the cellular network maintained at speeds from 120 km/h to 350 km/h (or even up to 500 km/h depending on the frequency band). MIMO = Multiple Input/Multiple Output antenna technology Page 5

6 Spectrum Holdings from FCC AT&T will not be compatible with VZ networks because of different spectrum and equipment. AT&T spectrum Verizon spectrum 6

7 LTE Security Architecture 2) Challenge / response authentication and key agreement (AKA) 1) Distribution of authentication data 128-bit encryption and integrity keys. Possibility to migrate later to 256 bits Snow3G (UMTS based) and AES (by US NIST) algorithms Challenge Response Visited network K UICC CK,IK To other networks HSS K,CK,IK K ASME UE K enb, K NAS X2 IPSec enb 3) Encrypt+integrity pr. (NAS* control signals) 3) Encrypt + integrity pr. (CP) S1 IPSec Switching / Routing MME Home network 3) Encrypt (UP) Encryption termination in enb CP = Control Plane UP = User Plane NAS = Non-Access Stratum protocol SAE-GW LTE uses AES 128 bit OTA encryption Specification allows for future upgrade to 256 bit encryption Access Stratum = communications between UE & enode B Non-Access Stratum = communications between UE and core network elements

8 8 LTE NETWORK ELEMENTS

9 LTE Reference Architecture 2G/3G SGSN 3GPP ACCESS HSS QoS MSC MME PCRF enode- B S1-C S1-U Serving Gateway PDN Gateway Operator s IP services (e.g., IMS, CCS) Home PLMN New Non 3GPP Networks epdg 3GPP AAA Trusted Non-3GPP IP Access Untrusted Non-3GPP IP Access Standards allow Connectivity between other networks Page 9

10 Architectural Convergence 3G 4G/HSPA+, LTE Co-existence 2G EDGE GERAN BSC A-Control A-Bearer 2G MSC Call Server D CS Core NTN PSTN 850Mhz & 1900Mhz Node B BTS Abis 3G/4G HSPA+ UTRAN Iub Iur Node B Iub RNC RNC 2G-MGw 3G-MGw H.248 3G MSC Call Server HLR SS7 SIGTRAN SCP GW SMSC Messaging Core IM GW Other Packet Networks MMSC 700Mhz enode B BSC: Base Station Controller BTS: Base Transceiver Station HLR: Home Location Register GERAN: GSM EDGE Radio Access Network GGSN: Gateway GPRS Support Network LTE: Long Term Evolution SMSC: Short Message Service Center MMSC: Multimedia Message Service Center 4G LTE eutran X2 enode B S1 S1 MSC: Mobile Switching Center NTN: National Tandem Network RNC: Radio network Controller SGSN: Serving GPRS Support Network UTRAN: Universal Terrestrial Radio Access Network IM GW: Instant Messaging Gateway 3G SGSN 2G SGSN Gn Gn GGSN IP Network PS Core PGW Gi HSS PCRF IMS Core CSCF AS Page 10

11 LTE Architecture Overview 2G/3G Correlations enode B (Enhanced Node B) base station MME (Mobility Management Entity) Connected to the MSC Handles similar paging functions SGW (Serving Gateway) Akin to an Enhanced SGSN PGW (PDN Gateway) Enhanced GGSN with firewall functionality built in HSS (Home Subscriber Server) HLR with presence (location) and application specific support build in PCRF (Policy Control and Routing Function) Has not equal in the 2G/3G environment. Page 11

12 Page 12 AT&T / LTE FUTURES

13 AT&T s Roadmap for Voice Capabilities over LTE 1. Initial launch of LTE -- support data only. No Voice capabilities. 2. Phase 2 -- Circuit Switched Fall Back (CSFB) 1. Voice calls will be pushed to 3G or 2G 2. CS or PS Fall Back are defined in the standards (thru the 3G-SGSN or thru the MSC). 3. Phase 3 -- Voice over LTE (VoLTE). 1. True native mode on LTE (IP Based) Page 13

14 Voice over LTE LTE Is Data Only & Requires An Overlay Voice Architecture Circuit Switch Fall Back (CSFB) LTE UE performs IRAT to 3G or 2G to establish voice call Device registered on both LTE and UMTS/GSM networks Pages delivered over SGs interface from MSC to MME Active data session may be handed over to UMTS/GSM One Voice (VoIMS) Standard Supported By AT&T No Circuit Switch requirement Jointly developed by carriers and vendors to support voice and SMS over IMS SIP based, real time media negotiation SRVCC required to maintain call continuity at LTE 2G/3G border Page 14

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