1. Aida BotonjićTieto1 LTE Aida Botonjić

2. Aida BotonjićTieto2 Why LTE? Applications: Interactive gaming DVD quality video Data download/upload Targets: High data rates at high speed Low latency Packet optimized radio access technology Goals: Improving efficiency Lowering costs Reducing complexity Improving services Making use of new spectrum opportunities and better integration with other open standards (such as WLAN and WiMAX)

3. Aida BotonjićTieto3 November 2004, 3GPP Rel8: Long-term Evolution (LTE) Related specifications are formally known as the evolved UMTS terrestrial radio access (E-UTRA) and evolved UMTS terrestrial radio access network (E-UTRAN) LTE encompasses the evolution of: - the radio access through the E-UTRAN - the non-radio aspects under the term System Architecture Evolution (SAE) Entire system composed of both LTE and SAE is called the Evolved Packet System (EPS) Introduction

4. Aida BotonjićTieto4 IP Transport Network Network Architecture Cost efficient two node architecture Fully meshed approach with tunneling mechanism over IP network Access gateway (AGW) Enhanced Node B (eNB) IP Service Network S1 X2 S1 AGW eNB

5. Aida BotonjićTieto5 Network Elements

6. Aida BotonjićTieto6 Protocol overview NAS RRC PDCP RLC MAC PHY UE RRC PDCP RLC MAC PHY eNB NAS MME Handovers Ciphering Segmentation HARQ Modulation, coding NAS RRC PDCP RLC MAC PHY UE RRC PDCP RLC MAC PHY eNB Control PlaneUser Plane Radio bearers Logical channels Transport channels Physical channels

7. Aida BotonjićTieto7 Frame structure WCDMA/HSPA: LTE:

8. Aida BotonjićTieto8 Channel Dependent Scheduling and Link adaptation Frequency-domain & Time-domain adaptation Focus transmission power to each user’s best channel portion Adaptive modulation (QPSK, 16QAM, 64QAM)

9. Aida BotonjićTieto9 LTE PHY – Main Technologies MIMO Multiple Input Multiple Output OFDM Orthogonal Frequency Division Multiplexing N Tx Transmit Antennas N Rx Receive Antennas

10. Aida BotonjićTieto10 LTE PHY - MIMO Basics Minimum antenna requirement: 2 at eNodeB 2 Rx at UE Transmission of several independent data streams in parallel => increased data rate The radio channel consists of N Tx x N Rx paths Theoretical maximum rate increase factor = Min(N Tx x N Rx )

11. Aida BotonjićTieto11 Sub-carriers are orthogonal All the sub-carriers allocated to a given user are transmitted in parallel. The carrier spacing is 15kHz LTE PHY - OFDM Basics

12. Aida BotonjićTieto12 Requirement comparison RequirementHSPA (Rel 6)LTE Peak data rate14 Mbps DL 5.76 Mbps UL 100 Mbps DL 50 Mbps UL 5% packet call throughput64 Kbps DL 5 Kbps UL 3-4x DL / 2-3x UL improvement Averaged user throughput900 Kbps DL 150 Kbps UL 3-4x DL / 2-3x UL improvement Control plane capacity> 200 users per cell (for 5MHz spectrum) User plane latency50 ms5 ms Call setup time2 sec50 ms Broadcast data rate384 Kbps6-8x improvement MobilityUp to 250 km/hUp to 350 km/h (500 km/h for wider bandwidths) Bandwidth5 MHz1.25, 2.5, 5, 10, 15, 20 MHz

13. Aida BotonjićTieto13 Feature comparison FeatureHSPA (Rel 6)LTE minimum TTI size2 ms1 ms ModulationDL: QPSK, 16 QAM UL: QPSK DL: QPSK, 16 QAM, 64 QAM UL: 16 QAM HARQAsync DL, Sync UL Fast schedulingTDS (time domain)TDS and FDS (frequency domain)

14. Aida BotonjićTieto14 Conclusion Scalable bandwidth Downlink and uplink peak data rates are 100 and 50 Mbit/s respectively for 20 MHz bandwidth. MIMO OFDM At least 200 mobile terminals in the active state for 5MHz bandwidth. If bandwidth is more than 5MHz, at least 400 terminals should be supported. PHY key technologies enable higher spectral efficiency, peak rate and lower latency