LTE/SAE Fundamentals Course

O BJECTIVES After completing this module, the participant should be able to: Understand the reasons driving to the LTE/SAE project. List the LTE/SAE main requirements. Discuss the future of wireless communications. Compare LTE/SAE capabilities with other mobile technologies. – Review the 3GPP specification work concerning LTE/SAE. Identify the major steps in the Network Architecture Evolution towards an LTE/SAE network. Underline the LTE/SAE key features. Briefly explain the basics of the LTE Air Interface. Name the Standardisation bodies around LTE/SAE.

M ODULE C ONTENTS Why LTE? LTE main requirements LTE versus other Mobile technologies LTE Specification work done and scheduled Network Architecture Evolution LTE key features Basics of the LTE Air Interface Standardisation around LTE LTE Summary

M ODULE C ONTENTS Why LTE? LTE main requirements LTE versus other Mobile technologies LTE Specification work done and scheduled Network Architecture Evolution LTE key features Basics of the LTE Air Interface Standardisation around LTE LTE Summary

A LITTLE BIT OF H ISTORY New technologies developed in the last 15 years in telecommunication brought available transmission rates to a total new level. Two systems have affected the life of nearly everyone: mobile communication via 2G network like GSM Wired & wireless data connectivity (xDSL & WLAN IEEE /a/b/g standards) 3G networks the first step towards a convergence between both networks

1. ¿W HY LTE?

T HE WAY TO LTE: 3 MAIN 3G LIMITATIONS 1. The maximum bit rates still are factor of 20 and more behind the current state of the art systems like n and e/m. Even the support for higher mobility levels is not an excuse for this. 2. The latency of user plane traffic (UMTS: >30 ms) and of resource assignment procedures (UMTS: >100 ms) is too big to handle traffic with high bit rate variance efficiently. 3. The terminal complexity for WCDMA or MC-CDMA systems is quite high, making equipment expensive, resulting in poor performing implementations of receivers and inhibiting the implementation of other performance enhancements.

T HE WAY TO THE L ONG -T ERM E VOLUTION (LTE): A 3GPP DRIVEN INITIATIVE LTE is 3GPP system for the years 2010 to 2020 and beyond. It shall especially compete with WiMAX e/m It must keep the support for high and highest mobility users like in GSM/UMTS networks The architectural changes are big compared to UMTS LTE shall be ready for commercial launch around 2010.

What are the LTE challenges? Best price, transparent flat rate Full Internet Click-bang responsiveness reduce cost per bit provide high data rate provide low latency The Users’ expectation…..leads to the operator’s challenges Price per Mbyte has to be reduced to remain profitable User experience will have an impact on ARPU LTE: lower cost per bit and improved end user experience UMTS HSPA I-HSPA LTE Cost per MByte HSPA LTE Throughput Latency Factor 10 Factor 2-3

R EDUCTION OF NETWORK COST IS NECESSARY TO REMAIN PROFITABLE Source: Light Reading (adapted) Traffic Profitability Revenue Revenues and Traffic decoupled Network cost Traffic volume €/bit Time Voice dominated Data dominated

M ODULE C ONTENTS Why LTE? LTE main requirements LTE versus other Mobile technologies LTE Specification work done and scheduled Network Architecture Evolution LTE key features Basics of the LTE Air Interface Standardisation around LTE LTE Summary

LTE = L ONG T ERM E VOLUTION Peak data rates of 173 Mbps/58 Mbps Low latency ms Enhanced consumer experience Scalable bandwidth of 1.4 – 20 MHz Easy to introduce on any frequency band OFDM technology Flat, scalable IP based architecture Decreased cost / GB Next step for GSM/WCDMA/HSPA and CDMA A true global roaming technology

S CHEDULE FOR 3GPP RELEASES Next step for GSM/WCDMA/HSPA and cdma2000 A true global roaming technology UMTS Rel 99/4 UMTS Rel 5 IMS HSDPA UMTS Rel 6 MBMS WLAN IW HSUPA UMTS Rel 7 IMS Evolution LTE Studies Specification : year LTE have been developed by the same standardization organization. The target has been simple multimode implementation and backwards compatibility. HSPA and LTE have in common: – Sampling rate using the same clocking frequency – Same kind of Turbo coding The harmonization of these parameters is important as sampling and Turbo decoding are typically done on hardware due to high processing requirements. WiMAX and LTE do not have such harmonization. UMTS Rel 8 LTE & EPC

C OMPARISON OF T HROUGHPUT AND L ATENCY (1/2) HSPA R6 Max. peak data rate Mbps Evolved HSPA (Rel. 7/8, 2x2 MIMO) LTE 2x20 MHz (2x2 MIMO) LTE 2x20 MHz (4x4 MIMO) Downlink Uplink HSPAevo (Rel8) LTE * Server near RAN Latency (Rountrip delay)* DSL (~20-50 ms, depending on operator) GSM/ EDGE HSPA Rel6 mi n max ms Enhanced consumer experience: - drives subscriber uptake - allow for new applications - provide additional revenue streams Peak data rates of 173 Mbps/58 Mbps Low latency ms

Scalable bandwidth Scalable bandwidth of 1.4 – 20 MHz Easy to introduce on any frequency band: Frequency Refarming ( Cost efficient deployment on lower frequency bands supported) S CALABLE B ANDWIDTH

I NCREASED S PECTRAL E FFICIENCY All cases assume 2-antenna terminal reception HSPA R7, WiMAX and LTE assume 2-antenna BTS transmission (2x2 MIMO) ITU contribution from WiMAX Forum shows downlink 1.3 and uplink 0.8 bps/Hz/cell Reference: - HSPA R6 and LTE R8 from 3GPP R HSPA R6 equalizer from 3GPP R HSPA R7 and WiMAX from /Nokia simulations OFDMA technology increases Spectral efficiency LTE efficiency is 3 x HSPA R6 in downlink HSPA R7 and WiMAX have Similar Spectral Efficiency

R EDUCED N ETWORK C OMPLEXITY Flat, scalable IP based architecture Flat Architecture: 2 nodes architecture IP based Interfaces Evolved Node B GateWay Flat, IP based architecture Internet IMSHLR/HSSMME ControlCoreAccess

LTE/SAE R EQUIREMENTS S UMMARY 1.Simplify the RAN: 1.Reduce the number of different types of RAN nodes, and their complexity. 2.Minimize the number of RAN interface types. 2.Increase throughput. 3.Reduce latency (which is a prerequisite for CS replacement). 4.Improve spectrum efficiency. 5.Provide greater flexibility with regard to the frequency bands in which the system may be deployed (Frequency Refarming) 6.Migrate to a PS only domain in the core network. 7. Provide efficient support for a variety of different services. Traditional CS services will be supported via VoIP, etc. 8.Minimise the presence of single points of failure in the network above the evolved Node Bs (eNBs). 9.Support inter-working with existing 3G systems and non-3GPP specified systems in order to support handover to/from these systems. 10.A more detailed list of the requirements and objectives for LTE can be found in TR from 3GPP.