LTE (LONG TERM EVOLUTION)

-presented byB.B.S.Sai Lakshmi

09K61A0509

CONTENTS

ABSTRACTINTRODUCTION4G WIRELESS STANDARDSTECHNOLOGIES ADOPTEDADVANTAGES AND DISADVANTAGES OF LTE

FUTURE SERVICES OVER 4G NETWORKSCONCLUSIONREFERENCES

ABSTRACT

Long term evolution (LTE) is the next major step

towards 4th generation of mobile

communications.

LTE introduces a new radio access network with

technologies that offer higher data rates,

efficiency and quality of services as well as

lower costs and the integration with the existing

open standards

INTRODUCTION 1G (Early 1980s)

– Analog speech communications.– Ex: AMPS

2G (Early 1990s)– Digital modulation of speech communications.– Advanced security and roaming.– TDMA and narrowband CDMA.– Ex: GSM

3G (Late 1990s)– Global harmonization and roaming.– Wideband CDMA– Ex: UMTS

GSM

Global System for Mobile Communication (GSM) Anybody – 500 million users (may 2001) Anywhere – 168 countries (may 2001) Any media – voice, messaging, data,

multimedia

GSM Architecture

OMC

Home Location Register

AuC

Equipment ID

Network Management Center

BTS

BTS

BTS

ME

ME

ME

Subscriber Identity Module

Subscriber Identity Module

Subscriber Identity Module

Base station controller

PSTN

Mobile switching center

Data communication network

BTS = Base Transceiver Station

AuC = Authentication Center

OMC = Operation and Maintenance Center

PSTN = Public Switched Telephone Network

ME = Mobile Equipment

Visitor Location Register

Beyond 3G• Evolutionary path beyond 3G• – Mobile class targets 100 Mbps with high

mobility• – Local area class targets 1 Gbps with low

mobility

• 3GPP is currently developing evolutionary/ revolutionary systems beyond 3G• – 3GPP Long Term Evolution (LTE)

• IEEE 802.16-based WiMAX is also evolving towards 4G through 802.16m

3GPP Evolution

Release 99 (Mar. 2000): UMTS/WCDMA Rel-5 (Mar. 2002): HSDPA Rel-6 (Mar. 2005): HSUPA Rel-7 (2007): DL MIMO, optimized real-

time services (VoIP, gaming, …) Long Term Evolution (LTE)

– 3GPP work on the Evolution of the 3G Mobile System started in November 2004.

– Standardized in the form of Rel-8.– Spec finalized and approved in January 2008.

LTE-Advanced study phase in progress.

Requirements for LTE Peak data rate

– 100 Mbps DL/ 50 Mbps UL within 20 MHz bandwidth.

– Up to 200 active users in a cell (5 MHz)– Less than 5 ms user-plane latency

Mobility– Optimized for 0 ~ 15 km/h.– 15 ~ 120 km/h supported with high

performance.– Supported up to 350 km/h or even up to 500

km/h. Spectrum flexibility: 1.25 ~ 20 MHz Enhanced support for end-to-end QoS

4G WIRELESS STANDARDS

The two competing bodies involved in churning out 4G wireless technologies are the 3GPP in Europe and the 3GPP2 in North America. The 3GPP is marketed under the brand name of Long Time Evolution or LTE and is working on the 4G technology which is to succeed the 3G technology of UMTS. The 3GPP2 project is marketed under the brand name Ultra Mobile Broadband or UMB and their effort is to make transition to 4G from the existing CDMA2000 family of standards in North America.

The High Level requirements for a 4G technology were identified as:

Higher spectral Efficiency Reduced cost per bit Increased Service Provisioning by

lowering the cost and increasing efficiency and experience

Open Interfaces as against closed technologies of the past

Power consumption efficiency Scalable and flexible usage of frequency

bands

Figure 1. 3GPP Overview .

TECHNOLOGIES ADOPTEDTwo generic technologies of OFDM and

MIMO that are adopted by LTE . System Architecture Evolution- the proposed architectural framework proposed specifically for LTE.

OFDM(Orthogonal Frequency Division

Multiplexing)

MIMO (Multiple Input Multiple

Output)

SAE (System Architecture Evolution)

OFDM(Orthogonal Frequency Division Multiplexing)

Orthogonal Frequency Division Multiplexing is a superior air access method compared to its predecessor CDMA. Also OFDM is one of the key technologies which enable non-line of sight wireless services making it possible to extend wireless access system over wide-areas.

It is a variant of the Frequency Division Multiplexing scheme in which the frequency channel is divided into multiple smaller sub-channels. In FDM, sub-channelization requires provisioning of guard bands between two sub-channels to avoid interference between them.

OFDM(CONTD) OFDM (as shown in Figure 2) divides the frequency

bandwidth in narrow orthogonal sub-parts called sub-carriers. A sub-channel is an aggregation of a number of these sub-carriers. The sub-carriers include data carriers, pilot carriers and a DC. The data carriers are used to carry data, the pilot carriers are used for channel sensing purposes and the DC mark the centre of the channel.

Each subcarrier is modulated with conventional modulation scheme such as Quadrature Amplitude Modulation or Phase Shift Keying at a low symbol rate. Each user is provided with a integer number of sub-channels which is composed of a number of sub-carriers. User data is carried parallely on each sub-carrier at a low rate. The combination of the parallel sub-carriers at the destination provide for the high data rates.

FIGURE 2 .OFDM

Because of its high-speed data transmission and effectiveness in combating the frequency selective fading channel, OFDM technique is widely used in wireless communication nowadays.

The advantages of OFDMo Immunity to delay spread and multipatho Resistance to frequency selective fadingo Simple equalization o Efficient bandwidth usage The disadvantages of OFDMo Synchronizationo Need FFT units at transmitter, receivero Sensitive to carrier frequency offseto High peak to average power ratio

MIMO (Multiple Input Multiple Output)

Multiple Input Multiple Output (MIMO) is one of the most popular Advanced Antenna Technologies which is supported both by LTE and UMB. The salient features of MIMO is that it offers higher throughput for a given bandwidth and higher link range for a given power value. A detailed discussion of the MIMO technology is beyond the scope of this survey and we provide a cursory glance at the key features of the technology. In MIMO the transceiver and receiver have multiple antennas giving MIMO multiple flavors based on the number of antennas present on each side.

Figure 3.MIMO

MIMO is a technique for boosting wireless bandwidth and range by taking advantage of multiplexing.In radio, multiple-input and multiple-output, or MIMO is the use of multiple antennas at both the transmitter and receiver to improve communication performance.

The advantages of MIMO are Capacity scales linearly with number of

antennas MIMO offers potential for

larger data rate larger number of users improved range/coverage better quality of service (QoS)

lower Tx power

The disadvantages of MIMO are Hardware complexity Software complexity Power consumption Battery lifetime of mobile devices Thermal problems Antenna spacing

SAE (System Architecture Evolution)

The SAE defines the core network architecture for the LTE standard.

The key features are : An all IP network - Evolution of the core

network towards flat, packet only all IP based architecture

Higher throughput, Lower latency radio access technologies.

interoperability across heterogeneous radio access technologies.

Vertical handover between multiple Radio Access Technologies

FIGURE 4. SAE

The SAE architecture is composed of two node types: Base station or ENodeB (evolved NodeB) AGW (Access Gateway)

As shown in Figure 4, The Mobility management entity (MME) is responsible for managing and maintaining user entity control plane context, authentication information, mobility management and generating temporary Identities. The 3GPP anchor is responsible for handling vertical handovers between 2G-3G and LTE. The SAE anchor is responsible for vertical handovers between 3GPP and non-3GPP sucha as WLAN etc. The link S3 in Figure 4 represents the user and bearer information exchangefor inter-3GPP access System mobility. Link S6 represents the AAA interface for transfer of user access and authentication data for user access to the evolved system. Link S4 denote mobility support between GPRS core and inter AS support. S7 represent transfer of QoS(Quality of Service) policy and transfer rules. Link S2 represents mobility support between WLAN 3GPP IP access or non-3GPP IP access and Inter AS anchor

ADVANTAGES AND DISADVANTAGES OF LTEADVANTAGES OF LTE

• LTE facilitates the current networks to perform on the better speed as well as for the new mobile applications.

• LTE decreases traffic of communication in terms of sending data.

• LTE allows more users to use the same frequency that result n increasing of mobile broad band users.

• LTE separates the frequencies into different channels to protect the each channel from disturbance .This solution was called orthogonal.

• LTE offers faster data rate transfer compared to the other 3G networks.

• LTE supports more data capacity because it focuses on VOIP(Voice Over Internet protocol)

• LTE allows wireless broadband providers to trasition to this new technology without rebuilding their entire networks from the ground  

               

DISADVANTAGES OF LTE The startup costs of the service

providers and customers for equipment upgrades are too high.

LTE technology need to use additional antennas at network base stations for data transmissions

FUTURE SERVICES OVER 4G NETWORKS Laptops, PDA's and fixed broadband

services Premium VOD(Video On

Demand)/MOD(Music On Demand) Services

Multimedia Upload and Exchange services

Consumer Electronics Business Applications for Vertical

Markets

CONCLUSION Data rates are growing rapidly in the mobile

networks which are a very good sign for LTE. End users are starting to use the data services which are available for them. More and more new services are launched to boost the usage of data in the mobile networks. To fulfill the growing demand operators needs to upgrade their networks to serve their customers better. LTE will bring 10 times higher data rates with 10 time’s lower Latency. LTE equipments are using less electricity, needs less cooling and are smaller in size. These advantages bring huge savings for operators

REFERENCESA. http://

www.nokiasiemensnetworks.com/portfolio/products/mobile-broadband/long-term-evolution-lte

B. www.google.comC. http://en.wikipedia.org/wiki/WikiD. http://www.radio-electronics.com/inf

o/cellulartelecomms/lte-long-term-evolution/3g-lte-basics.php

E. http://tech.saroscorner.com/2009/10/are-you-looking-for-long-term-evolution.html