1 10.11.2010
LTE System Architecture Evolution
T-110.5120 Next Generation Wireless Networks
Lecture 10.11.2010
Risto Mononen <risto@monoplan.fi>
2 10.11.2010
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
3
10.11.2010 Source: www.3gpp.org/LTE
4 10.11.2010
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
5 10.11.2010
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
6 10.11.2010
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/j ournal_conference_papers/wireless_access/VT C08F_jading.pdf
Source: www.3gpp.org/LTE
7 10.11.2010
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
8 10.11.2010
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
9 10.11.2010
2G / 3G / 4G cellular networks
Wireless access evolution
10 10.11.2010
LTE interworking with 2G/3G accesses
Source: Ericsson, ”LTE – an introduction”, White paper, 2009
11 10.11.2010
GSM/UMTS network
MSC GMSC PSTN
UE BSC
RNC
HLR
EIR PCRF Operator
services BTS
NB
SGSN GGSN Internet
12 10.11.2010
Evolution to One tunnel
UE NB RNC GGSN Internet
SGSN
13 10.11.2010
Evolution to I-HSPA
UE NB
RNC
SGSN
GGSN Internet
14 10.11.2010
Evolution to LTE
UE eNB
MME
SGW
PDN GW Internet
15 10.11.2010
VoIP with IMS
CS fallback and SR-VCC NSN Voice over LTE
LTE voice service
16 10.11.2010
IP Multimedia Subsystem
Source: www.3gpp.org S -
MGCF CSCF Cx HSS
IM
MGW Mn
Mb
Mg
MRFP Mb
Mb I-CSCF
Mw
Mw
Gm
Mj Mi
BGCF Mk
C, D, Gc, Gr
UE Mb
Mb
Mb Dx SLF
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
17 10.11.2010
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 have any impacts to the User plane handling.
Source: www.3gpp.org
18 10.11.2010
CSFB signalling
UE/MS eNodeB BSS/RNS MME MSC 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
19 10.11.2010
Single Radio Voice Call Continuity to 2G/3G
UE E-UTRAN
MME MSC Server Target
UTRAN/GERAN
Serving/PDN GW
3GPP IMS
UE Um/Uu Iu-cs/A
S3
Sv
S1-MME S11
S1-U
EUTRAN-Uu SGi
HSS S6a
SGSN Iu-ps/Gb
Figure 5.13: SRVCC architecture for E-UTRAN to 3GPP UTRAN/GERAN
Source: www.3gpp.org
20 10.11.2010
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
●
