GSM TOWARDS LTE NETWORKS

Lecture # 6

LTE

Many names ...

LTE - Long Term Evolution eUTRAN

SAE - System Architecture Evolution EPS (Evolved Packet System)

Introduction

LTE/SAE

What is 3GPP? 3GPP stands for 3rd Generation Partnership Project It is a partnership of 6 regional SDOs (Standards Development Organizations)

These SDOs take 3GPP specifications and transpose them to regional standards

Japan

USA

Towards LTE

LTE Access LTE radio access

Downlink: OFDM Uplink: SC-FDMA

Advanced antenna solutions Diversity Beam-forming Multi-layer transmission

(MIMO)

Spectrum flexibility Flexible bandwidth New and existing bands Duplex flexibility: FDD and

TDD

20 MHz1.4 MHz

TX TX

SC-FDMA

OFDMA

Terminology Updates

EPC = Evolved Packet core (earlier SAE=System Architecture Evolution).

e UTRAN = Evolved UTRAN (earlier LTERAN = Long Term Evolution).

EPS = Evolved Packet Systems including EPC and Terminals.

LTE Offer’s

Performance and capacity

DL 100 Mbps AND UL 50 Mbps

Simplicity

Flexible Bandwidths (5Mhz-20Mhz),

FDD and TDD

plug-and-play Devices

self-configuration Devices

self-optimization Devices

LTE (Long Term Evolution) Radio Side (LTE – Long Term Evolution)

Improvements in spectral efficiency, user throughput, latency

Simplification of the radio network Efficient support of packet based services

Network Side (SAE – System Architecture Evolution) Improvement in latency, capacity, throughput Simplification of the core network Optimization for IP traffic and services Simplified support and handover to non-3GPP access

technologies

LTE Objectives Reduced cost per bit

Improve spectrum efficiency ( e.g. 2-4 x Rel6) Reduce cost of backhaul (transmission in UTRAN)

Increased service provisioning – more services at lower cost with better user experience

Focus on delivery of services utilising ”IP” Reduce setup time and round trip time Increase the support of QoS for the various types of services

(e.g. Voice over IP) Increase peak bit rate (e.g. above 100Mbps DL and above

50Mbps UL) Allow for reasonable terminal power consumption

Evolution Path Architecture

The pay load is to be directed to a tunnel (eUTRAN)

Payload goes directly from the evolved node B to the Gateway

Control plane is directed at the Mobility management end.

LTE

Core Nodes of LTE Serving GPRS Support Node (SGSN) - to provide connections for

GERAN (GSM Radio Access Network) and UTRAN Networks (UMTS Terrestrial Radio

Access Network) Serving Gateway - to terminate the interface toward the 3GPP radio-access networks

PDN Gateway - to control IP data services like routing, addressing, policy enforcing and providing access to non-3GPP access networks

Mobility Management Entity (MME) - to manage control plane context, authentication and authorization

3GPP anchor - to manage mobility for 2G/3G and LTE systems

SAE anchor - to manage mobility for non 3GPP RATs

Policy Control and Charging Rules Function (PCRF) - to manage Quality of Service (QoS) aspects

PDN GWServing GW

MME

S1-MME S1-U

LTE

IP networks

eNodeB

SGSN

Iu CPGb

2G 3G

S3

BSC

BTS

RNC

Node B

HLR/HSS

PCRF

Iu UP

S11

Gr

S10

S6a

SGi

X2

Iur

S7

Non-3GPP access

S2a/b

The PDN and Serving GW may be separate nodes in some scenarios

(S5 in-between)Only PS Domain shown

S4

From 3GPP to LTE/SAE

PDN Gateway - to control IP data services like routing, addressing, policy enforcing and providing access to non-3GPP access networks

MME Functionality Roaming (S6a towards home HSS) Authentication SAE GW selection Idle mode mobility handling

Tracking Area Update Paging

Mobility handling of inter-MME (pool) handover (triggered by eNodeB) inter-RAT handover (triggered by eNodeB)

QoS “negotiation” with UE and eNodeB Security

Ciphering and integrity protection of NAS signalling Secure control signalling transport on S1 interface (unless taken care of

by a SEG (Security Gateway)) O&M security (?)

SAE CN ArchitectureSGi

MME

S1-MME S1-U

S11

X2

S10

eNodeB

S3

S4

SGSNSAE GW

SAE GW Functionality PDN SAE GW:

Policy Enforcement Per-user based packet filtering (by e.g. deep packet inspection) Charging Support User plane anchor point for mobility between 3GPP accesses and non-3GPP accesses routing of user data towards the S-GW Security

O&M security (?) Lawful Intercept

Serving SAE GW: User plane anchor point for inter-eNB handover (within one pool) User plane anchor point for inter-3GPP mobility routing of user data towards the eNodeB routing of user data towards the P-GW routing of user data towards the SGSN (2G and 3G) or RNC (3G with “Direct Tunnel”) Security

Secure user data transport on S1 interface (unless taken care of by a SEG (Security Gateway)) O&M security (?)

Lawful Intercept

The PDN SAE GW and the Serving SAE GW may be implemented in one physical node or separated physical nodes.

…

SAE CN ArchitectureSGi

MME

S1-MME S1-U

S11

X2

S10

eNodeB

S3

S4

SGSNSAE GW

Why LTE/SAE?Driving Factors for LTE/SAE

Ensuring that 3G is attractive in comparison with competing technologies (WiFi, WiMax, Flarion, …)

LTE/SAE architecture Competing technologies looks simpler (fewer nodes) OPEX (fewer node types to manage)

Significantly increased peak data rate Competing technologies provide higher data rates End-user experience

Reduced user plane latency Necessary to achieve increased data rates End-user experience

Significantly reduced control plane latency End-user experience

Improved Performance(compared to WCDMA)

Introduction

Perception

LTE – Performance Targets High data rates

Downlink: >100 Mbps Uplink: >50 Mbps Cell-edge data rates 2-3 x HSPA Rel. 6 (@ 2006)

Low delay/latency User plane RTT: Less than 10 ms ( RAN RTT ) Channel set-up: Less than 100 ms ( idle-to-active )

High spectral efficiency Targeting 3 X HSPA Rel. 6 (@ 2006 )

High performance for broadcast services

Spectrum flexibility Operation in a wide-range of spectrum allocations Wide range of Bandwidth Support for FDD, Half-duplex FDD and TDD Modes

Cost-effective migration from current/future 3G systems

Focus on services from the packet-switched domain !

Introduction

LTE/SAE Architecture

LTE/SAE Architecture (release 8)Functional changes compared to the current UMTS Architecture

Moving all RNC functions to the Node B ……, SGSN CP functions to the MME, and GGSN functions to the SAE GW.

GGSN

SGSN

RNC

P-GWS-GW

PDN GateWay Serving GateWay

Node B / HSPA eNodeB

MME Mobility Management Entity(not user plane functions)

LTE/SAE Architecture

LTE Architecture

eNB eNB

eNB

MME/UPE MME/UPE

S1

X2

X2

X2

EPC

E-UTRAN

Evolved Packet Core

MME/UPE = Mobility Management Entity/User Plane Entity

eNB = eNodeB

Evolved Packet Switching Network Architecture

MMEMME

P-GW/S-GWP-GW/S-GW

MMEMME MMEMME

P-GW/S-GWP-GW/S-GW P-GW/S-GWP-GW/S-GW P-GW/S-GWP-GW/S-GW

LTE NODE B LTE NODE B LTE NODE B

LTE NODE BLTE NODE B

S11

S1-Cp

X2

Gi

Interfaces

Air Interface

E

P

C

EUTRAN

LTE/SAE ArchitectureMain SAE interfaces (non-roaming case)

S1-MME S1-U

IP networks

S3 S11

S10

SGi

S4

S5/S8

(SGi)

X2

SAE CN Architecture

OSS-RC

S1-MME: control plane protocol between eNodeB and MME

S1-U: user plane tunneling interface between eNodeB and Serving GW

S5: user plane tunneling interface between Serving GW and PDN GW

S8: user plane tunneling interface between Serving GW and PDN GW for roaming

S10: control plane interface between MME and MME

S11: control plane interface between MME and Serving GW.

S4: *)user plane tunneling interface between SGSN and PDN GW

S3: *)control plane interface between MME and SGSN.

O&M interfaces: OSS-RC – MME OSS-RC – SAE GW

Note: Interfaces non-3GPP accesses not covered.

SAE GWMME

eNodeB

SGSN

SAE GW(in some usecases only)

2G Towards 3G Networks

GGSN

IP networks

SGSN

IuGb

2G 3G

BSC

BTS

RNC

Node B

HLR

PCRFGr

Gi

Iur

Gx

Only PS Domain shown

Gn Gn

•Policy Control and Charging Rules Function (PCRF) - to manage Quality of Service (QoS) aspects

GGSN

IP networks

SGSN

Iu CPGb

2G 3G

BSC

BTS

RNC

Node B

HLR/HSS

PCRF

Iu UP

Gr

Gi

Iur

Gx

Only PS Domain shown

Gn

Optimizing the 3G/HSPA payload plane for Broadband traffic

HSPA (Higher Speed Packet Access)

10 Mb/s

From 3GPP Release 6 to LTE/SAE Improving performance with LTE/SAE; 3GPP Release 8

PDN GWServing GW

MME

S1-MME S1-U

LTE

IP networks

eNodeB

SGSN

Iu CPGb

2G 3G

S3

BSC

BTS

RNC

Node B

HLR/HSS

PCRF

Iu UP

S11

Gr

S10

S6a

SGi

LTE/SAE Architecture

X2

Iur

S7

Non-3GPP access

S2a/b

The PDN and Serving GW may be separate nodes in some scenarios

(S5 in-between)

A flat architecture for optimized performance and cost efficiency

Only PS Domain shown

(Additions/changes in red.)

S4

LTE/SAE Architecture Product dimension

PDN GWServing GW

MME

S1-MME S1-U

LTE

IP networks

eNodeB

SGSN

Iu CPGb

2G 3G

S3

BSC

BTS

RNC

Node B

HLR/HSS

PCRF

Iu UP

S11

Gr

S10

S6a

SGi

LTE/SAE Architecture

X2

Iur

S7

Non-3GPP access

S2a/b

S4PDN GW

Serving GW

”Gateway”

MMESGSN

”Mobility Server”

PCRF

HLR/HSS

”HLR/HSS”

EPC

eNode B

RBS

OSS

PA/DU Core & IMS

PA/DU Radio

+ True high-speed mobile data

+ Full-motion HD video anywhere

+ Stream any content

+ Mobile peer2peer & Web 2.0

(Networking)

+ Triple play

EDGE

EVDO-AHSDPA

LTEFiber

ADSL-2+

ADSL

Mbps

40-100MbpsFiber like speed on mobile

Comparison with Speed

+ Spectral efficiencyBetter utilization of spectrum available

+ Low frequency, Advanced Receivers and Smart AntennaFor improved coverage and reduced cost of ownership

+ Increased CapacityMuch higher user and sector throughput for lower individual cost service delivery

+ Simpler RAN, IP Core & Centralized service deliveryFewer nodes & interfaces (Node-B/RNC/Gateway) One Network & IMS for all access technologies

+ Connect to legacy coresExisting network asset investment protection

+ 3GPP/2 Market tractionEconomy of scale

LTE VoIP cost*

UMTS rel.99 voice call cost$

10%

3GPP subscribers 85% market share

Predicted LTE VoIP voice call cost* - Sound Partners Limited Research

Comparison Cost

10-5msec latencyHighly Responsive Multimedia

+ Improved user experience

+ Fast VoIP call set-up

+ Instantaneous web pages

+ Streaming fast buffering

+ Online mobile gamingEDGE

EVDO-AHSDPA

LTEFiber

ADSL-2+

ADSL

Response Time

LTE Time Line

3G- R’993G- R’99HSPAHSPA

HSPA EvolutionHSPA Evolution

LTELTE

2002 2005 2008/2009 2009

384 kbps 3.6 Mbps 21/28/42 Mbps ~150 MbpsPeak rate

2007

7/14 Mbps

Mobile broadband speed evolution

LTE EvolutionLTE Evolution

2013

1 Gbps

Target

www.lte.yolasite.com

Thanks