110.11.2010

LTE System Architecture Evolution

T-110.5120 Next Generation Wireless Networks

Lecture 10.11.2010

Risto Mononen <risto@monoplan.fi>

210.11.2010

Motivation for 3GPP Release 8 - The LTE Release

● Need to ensure the continuity of competitiveness of the 3G system for the future

● User demand for higher data rates and quality of service

● Packet Switch optimized system

● Continued demand for cost reduction (CAPEX and OPEX)

● Low complexity

● Avoid unnecessary fragmentation of technologies for paired (FDD) and unpaired (TDD) band operation

● OFDM; FFT & IFFT

Source: www.3gpp.org/LTE

310.11.2010 Source: www.3gpp.org/LTE

410.11.2010

High level requirements

● Increased peak data rates: 100Mbps downlink and 50Mbps uplink.

● Reduction of RAN latency to 10ms

● Improved spectrum efficiency (two to four times compared with HSPA Release 6)

● Cost-effective migration from Release 6 Universal Terrestrial Radio Access (UTRA) radio interface and architecture

● Improved broadcasting

● IP-optimized (focus on services in the packet switched domain)

● Scalable bandwidth of 20MHz, 15MHz, 10MHz, 5MHz, 3MHz and 1.4MHz

● Support for both paired and unpaired spectrum

● Support for inter-working with existing 3G systems and non-3GPP specified systems

Source: www.3gpp.org/LTE

510.11.2010

Self-organizing networks (SON)●Automated configuring, operating and optimizing of cellular access network ●Introduced in Release 8, but more details in future releases●Interoperability?

Source: Nokia Siemens Networks

610.11.2010

LTE-Release 8 User Equipment Categories

“The link performance of current cellular systems such as LTE is already quite close to the Shannon limit.”

http://www.ericsson.com/res/thecompany/docs/journal_conference_papers/wireless_access/VTC08F_jading.pdf

Source: www.3gpp.org/LTE

710.11.2010

LTE Release 8 Key Features

● High spectral efficiency

● OFDM in Downlink, MIMO

● DFTS-OFDM(“Single-Carrier FDMA”) in Uplink, Low PAPR

● Very low latency

● Short setup time & Short transfer delay

● Short HO latency and interruption time; Short TTI

● Support of variable bandwidth

● 1.4, 3, 5, 10, 15 and 20 MHz● Simple Architecture

● Inter-working with other systems, e.g. cdma2000

● FDD and TDD within a single radio access technology

● Support of Self-Organising Network (SON) operation

Source: www.3gpp.org/LTE

810.11.2010

LTE in the news

● 14 December 2009: TeliaSonera launches commercial LTE in Stockholm and Oslo

● 26 June 2010: TeliaSonera opens LTE network in Malmo & Gothenburg

● 22 September 2010: MetroPCS launches country's first LTE network, world's first LTE handset

● 22 October 2010: Deutsche Telekom first to deploy LTE in digital dividend spectrum – launch during 2010

910.11.2010

2G / 3G / 4G cellular networks

Wireless access evolution

1010.11.2010

LTE interworking with 2G/3G accesses

Source: Ericsson, ”LTE – an introduction”, White paper, 2009

1110.11.2010

GSM/UMTS network

MSC GMSC PSTN

UEBSCRNC

HLREIR

PCRFOperator services

BTSNB

SGSN InternetGGSN

1210.11.2010

Evolution to One tunnel

UE NB RNC GGSN Internet

SGSN

1310.11.2010

Evolution to I-HSPA

UE NB

RNC

SGSN

GGSN Internet

1410.11.2010

Evolution to LTE

UE eNB

MME

SGWPDN GW

Internet

1510.11.2010

VoIP with IMS

CS fallback and SR-VCC

NSN Voice over LTE

LTE voice service

1610.11.2010

IP Multimedia Subsystem

Source: www.3gpp.org

S - CSCF

MGCF HSS Cx IM

MGW M n

Mb

Mg

MRFP

Mb

Mb I-CSCF

Mw

Mw

Gm

Mj Mi

BGCF

Mk

C, D, Gc, Gr

UE

Mb

Mb

Mb SLF Dx

Mp

CS

CS

IMS Subsystem

Cx

AS

ISC

Sh

Ut

BGCF

Mg

Dh

Ma

P-CSCF

Mx

Mx

Mx

CS Network Mm

Legacy mobile

signalling Networks Mm Mm

TrGW

IP Multimedia Networks

IBCF

Ix

Ici, Mm Izi

MRB

Rc ISC

Mr

MRFC Cr, Mr’

Figure 4.0: Reference Architecture of the IP Multimedia Core Network Subsystem

1710.11.2010

CS Fallback to 2G/3G

UE

E-UTRAN-Uu

E-UTRAN MME

S1-MME

UTRAN

GERAN

Um

Uu MSC/VLR

Iu-CS

A

SGs

Figure 5.12: Configuration of CSFB

NOTE: The MGW is not shown in the figure 5.12 since the CS fallback in EPS does not haveany impacts to the User plane handling.

Source: www.3gpp.org

1810.11.2010

CSFB signalling

UE/MS MME BSS/RNS MSC eNodeB SGSN Serving

GW

2. Optional Measurement Report Solicitation

4b. A/Iu-cs message (with CM Service Request) 4b. CM Service Request

Location Area Update or Combined RA/LA Update

5. CM Service Reject 5. CM Service Reject

If the MSC is changed

3a. PS HO as specified in 23.401 [2] (preparation phase and start of execution phase)

6. CS call establishment procedure

1a. Extended Service Request

1b. S1-AP Request message with CS Fallback indicator

7. PS HO as specified in 23.401 [2] (continuation of execution phase)

1c. S1-AP Response message

4a. Location Area Update or Combined RA/LA Update

3c. Update Bearer(s) 3b. Suspend

P-GW/ GGSN

Source: www.3gpp.org

LTE access

2G/3G access

1910.11.2010

Single Radio Voice Call Continuity to 2G/3G

UE E-UTRAN

MME

MSC ServerTarget

UTRAN/GERAN

Serving/PDNGW

3GPPIMS

UEUm/Uu Iu-cs/A

S3

Sv

S11S1-MME

S1-UEUTRAN-Uu SGi

HSSS6a

SGSN

Iu-ps/Gb

Figure 5.13: SRVCC architecture for E-UTRAN to 3GPP UTRAN/GERAN

Source: www.3gpp.org

2010.11.2010

References etc.

● 3GPP TS 23.002, 23.204, 23.272, 23.401● Use the latest spec in seminars and thesis● Rel 10 topics to look for:

● Carrier aggregation● Relay station● Femto BTS and WLAN interworking● Access Network Discovery and Selection

Function (ANDSF)