Post on 05-Apr-2018
7/31/2019 3GPP LTE Evolved Packet System
1/43
3GPP LTE Evolved Packet System(and what it has to do with Femtocells)
A. Maeder, G. Punz, S. SchmidNEC Laboratories Europe
andreas.maeder@neclab.eu
7/31/2019 3GPP LTE Evolved Packet System
2/43
andreas.maeder@neclab.eu
From GSM over UMTS to LTE and LTE-Advanced: the roots of
next generation mobile network standards
Overview of the Evolved Packet System Architecture
Overview of E-UTRAN
Femtocells in LTE/EPS
Outlook on LTE-Advanced and beyond
Outline
BeFemto Winter School 20122
7/31/2019 3GPP LTE Evolved Packet System
3/43
andreas.maeder@neclab.eu
From GSM over UMTS to LTE and LTE-Advanced: the roots ofnext generation mobile network standards
BeFemto Winter School 20123
7/31/2019 3GPP LTE Evolved Packet System
4/43
andreas.maeder@neclab.eu
Progression of cellular peak data rates
GSM
GPRS
UMTS
EDGE
HSDPA
WiMAXHSPA+
LTE
LTE-A
WiMAX 2.0
1
10
100
1,000
10,000
100,000
1,000,000
1990 1995 2000 2005 2010 2015 2020
Peak data rates over time
DataRates[kBit/s]
BeFemto Winter School 20124
2G 2.5G 3G 3.5G 4G B4G?
Means to achievehigher data rates:
More spectrum, moreefficient RRM, smaller
cells (femtocells)
ITU-R req. for IMT-Advanced
7/31/2019 3GPP LTE Evolved Packet System
5/43
andreas.maeder@neclab.eu
Motivations and Drivers for LTE/SAE (1/2)
There seems to be a common understanding in the mobilecommunications industry that the technical and commercial
evolution of this industry sector points towards an AIPN.
User related and social drivers:
affordable high-speed
mobile access support of diverse mobile
network services
seamless serviceexperience across
access technologies ability to obtain low-cost
low-end services and highpriced high-end services
5 BeFemto Winter School 2012
TR 22.987
7/31/2019 3GPP LTE Evolved Packet System
6/43
andreas.maeder@neclab.eu
Motivations and Drivers for LTE/SAE (2/2)
Drivers from a business perspective: handle large volumes of IP traffic in a cost effective manner support user-to-user and user-to-multicast traffic incorporate non-3GPP access technologies with minimum impact interworking with other networks (considering mobility, security,
charging and QoS)
account for fixed/mobile convergence issues Drivers from a technology perspective significantly higher data rates to end-users multiple radio access systems
Drivers from competing standards: Mobile WiMAX challenged market and technology leadership of
3GPP systems
6 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
7/43andreas.maeder@neclab.eu
Convergence of radio technologies
Five reasons why OFDMA has won: Robust in multipath environments due to cyclic prefix
Flexible spectrum allocation by adjusting the number of OFDM subcarriers
Efficient receiver hardware implementations
Simple MIMO implementation in frequency domain
Utilization of frequency diversity gain
BeFemto Winter School 20127
TDMA/FDMA
CDMA/WCDMA OFDMA
2G 2.5G 3G 3.5G 4G
GSM
EGPRS/EDGE
HSCSD
IS-95CDMA
2000
UMTS
Rel. 99
1xEV-DO
HSPA HSPA+ LTE Rel. 8LTE Rel. 10
LTE-Advanced
Mobile WiMAX
(IEEE 802.16e)
Mobile WiMAX 2
(IEEE 802.16m)
Fixed WiMAX
(IEEE 802.16d)
LTE-Advanced
Rel. 11
3.8G
7/31/2019 3GPP LTE Evolved Packet System
8/43andreas.maeder@neclab.eu
Overview of 3rd Generation Partnership Project
Founded 1998 by ARIB, ETSI, T1 (ATIS), TTA and TTC Current orginizational partners:
ARIB (Japan), ATIS (US), CCSA (PRC), ETSI (EU), TTA (Korea), TTC (Japan)
Market relationship to many otherinterest organizations, such asFemtoForum, GSMA, UMTS Forum, ...
Scope: Originally: Technical specifications and reports for a 3G mobile system based on
CEPTs GSM (Global System for Mobile Communication/Groupe Spcial Mobile)
Resulted in Universal Mobile Telecommunication System (UMTS)
Today responsible for many mobile communication technologies:
Maintenance of GSM, GPRS and EGDE Further development and maintenance of UMTS/UTRAN Development of evolved UTRAN (E-UTRAN) and 3GPP core network evolution 3GPP considers the long term evolution
BeFemto Winter School 20128
7/31/2019 3GPP LTE Evolved Packet System
9/43andreas.maeder@neclab.eu
3GPP Standard releases
Stable releases across all documents of all specification groups
After freezing date, no new major features will be added Some major 3GPP releases:
BeFemto Winter School 20129
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
UMTS Rel. 99
UMTS Rel. 4
UMTS Rel. 5 (HSDPA)
UMTS Rel. 6 (Enhanced Uplink, HSPA)
UMTS Rel. 7 (HSPA+)
IMS
LTE Rel. 8 (EPS)
LTE Rel. 9
LTERel 10
7/31/2019 3GPP LTE Evolved Packet System
10/43andreas.maeder@neclab.eu
3GPP technical specification groups
BeFemto Winter School 201210
Overall steering and managementAdoption of work items
Maintenance/
developmentof GSM/GPRS/
EDGE RAN
Maintenance/development
of UMTS/HSPA/
LTE RAN
Systemarchitecture,
servicecapabilities,
codecs (inc. EPC)
CN interfaces,protocols,
interworking, IMS,terminals, SIM
7/31/2019 3GPP LTE Evolved Packet System
11/43andreas.maeder@neclab.eu
Overview of the 3GPP Document Structure
Subject of specification series 3G and beyond / GSM (R99 and later) GSM only (Rel-4 and later)GSM only (beforeRel-4)
General information (long defunct) 00 series
Requirements 21 series 41 series 01 series
Service aspects ("stage 1") 22 series 42 series 02 series
Technical realization ("stage 2") 23 series 43 series 03 series
Signalling protocols ("stage 3") - user equipmentto network
24 series 44 series 04 series
Radio aspects 25 series 45 series 05 series
CODECs 26 series 46 series 06 series
Data 27 series 47 series (none exists) 07 series
Signalling protocols ("stage 3") -(RSS-CN) andOAM&P and Charging (overflow from 32.-range)
28 series 48 series 08 series
Signalling protocols ("stage 3") - intra-fixed-network
29 series 49 series 09 series
Programme management 30 series 50 series 10 series
Subscriber Identity Module (SIM / USIM), ICCards. Test specs.
31 series 51 series 11 series
OAM&P and Charging 32 series 52 series 12 series
Access requirements and test specifications 13 series (1) 13 series (1)
Security aspects 33 series (2) (2)
UE and (U)SIM test specifications 34 series (2) 11 series
Security algorithms (3) 35 series 55 series (4)
LTE (Evolved UTRA) and LTE-Advancedradio technology
36 series - -
Multiple radio access technology aspects 37 series - -
Technical realization of core network,
mobility management, quality of service,IMS, etc.
Some important specifications here:TS 23.401 , 23.402
"Stage 1" refers to the service
description from a service-users point ofview."Stage 2" is a logical analysis, breakingthe problem down into functionalelements and the information flowsamongst them across reference pointsbetween functional entities."Stage 3" is the concreteimplementation of the protocolsappearing at physical interfaces between
physical elements onto which thefunctional elements have been mapped.
BeFemto Winter School 201211
LTE PHY and MAC, LTE overalldescription document (TS 36.300)
UMTS PHY and MAC
Incl. mobility enhancements for HeNB
http://www.3gpp.org/ftp/Specs/html-info/00-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/21-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/41-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/01-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/22-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/42-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/02-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/23-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/43-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/03-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/24-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/44-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/04-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/25-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/45-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/05-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/26-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/46-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/06-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/27-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/07-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/28-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/48-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/08-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/29-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/49-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/09-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/30-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/50-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/10-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/31-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/51-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/11-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/32-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/52-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/12-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/33-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/34-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/11-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/35-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/55-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/36-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/37-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/37-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/36-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/55-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/35-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/11-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/34-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/33-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/12-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/52-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/32-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/11-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/51-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/31-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/10-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/50-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/30-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/09-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/49-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/29-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/08-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/48-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/28-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/07-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/27-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/06-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/46-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/26-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/05-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/45-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/25-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/04-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/44-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/24-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/03-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/43-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/23-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/02-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/42-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/22-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/01-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/41-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/21-series.htmhttp://www.3gpp.org/ftp/Specs/html-info/00-series.htm7/31/2019 3GPP LTE Evolved Packet System
12/43andreas.maeder@neclab.eu
Overview of the Evolved Packet System Architecture
BeFemto Winter School 201212
7/31/2019 3GPP LTE Evolved Packet System
13/43andreas.maeder@neclab.eu
Basic Principles of the Evolved Packet System (EPS)
The EPS comprises the Evolved Packet Core (EPC) and the EvolvedUTRAN (E-UTRAN)
EPS is designed to be a purelypacket switched systemIMS (IP Multimedia Subsystem) targeted as voice service platform
EPS for 3GPP accesses similar to GPRS Core,but more flat
Reduction of nodes in user plane path: 4 3 nodes
GTP remains main protocol for 3GPP accesses
EPSenables interworking with non-3GPP accesses (WLAN,WiMAX, CDMA2000, ) IP Mobility between 3GPP accesses and non-3GPP accesses based
on PMIPv6 (Proxy Mobile IPv6) or DSMIPv6 (Dual-Stack Mobile IPv6)
13 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
14/43andreas.maeder@neclab.eu
3GPPAccess
EPS for 3GPP Accesses
PDN GW: IP address allocation, charging and enforces QoS Serving GW: Local mobility anchor for intra-3GPP HO MME: Mobility management entity for intra-3GPP mobility, paging,
authentication, bearer management, etc. PCRF: QoS and charging rule provisioning
SGi
S1-MME
Operator's IPServices
(e.g. IMS, PSS etc.)
S10
PCRF
Gx Rx
UE
LTE-Uu
S11S5Serving
Gateway
PDN
GatewayS1-U
S12
S3
SGSN
S4
UTRAN
GERAN
GTP Interface
MME
S6a
HSS
HPLMNVPLMN
GTP or PMIP Interface
E-UTRAN
PCC Interface14 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
15/43andreas.maeder@neclab.eu
3GPPAccess
EPS for 3GPP Accesses
PDN GW: IP address allocation, charging and enforces QoS Serving GW: Local mobility anchor for intra-3GPP HO MME: Mobility management entity for intra-3GPP mobility, paging,
authentication, bearer management, etc. PCRF: QoS and charging rule provisioning
S12
S3
SGSN
S4
UTRAN
GERAN
GTP Interface
SGi Operator's IPServices
(e.g. IMS, PSS etc.)
PCRF
Gx Rx
S5Serving
Gateway
PDN
Gateway
S6a
HSS
HPLMNVPLMN
GTP or PMIP Interface
S1-MME
S10UE
LTE-Uu
S11
S1-U
MME
E-UTRAN
PCC Interface
SGi
PCRF
Gx
S6a
HSS
Operator's IPServices
(e.g. IMS, PSS etc.)
Rx
S5Serving
Gateway
PDN
Gateway
3GPPAccess
15 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
16/43andreas.maeder@neclab.eu
EPS for non-3GPP Accesses
SGi
PCRF
Gx
HSS
Operator's IPServices
(e.g. IMS, Internet)
HPLMN
Non-3GPPNetworks
RxGxc
S5
S6a
3GPPAccess
ServingGateway
PDNGateway
S2b
SWn
UntrustedNon-3GPP
Access
UE
SWu
ePDG
PMIP InterfacePCC InterfaceAAA Interface
SWx
S6b
SWm
SWa
3GPP AAAServer
STa
S2a
Gxa
A-GW
Trusted Non-3GPP Access
Serving GW: Bearer binding PDN GW: Inter-access
system mobility anchor
ePDG: Security GWfor untrusted acesses
16 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
17/43andreas.maeder@neclab.eu
Quality of Service: Bearer Architecture
QoS control in EPS is based on bearers: UEPDN-GW
IP traffic is mapped to bearers by means of traffic flow templates (TFT)
One-to-one mapping between radio bearer and S1 bearer
BeFemto Winter School 201217
P-GWS-GW PeerEntity
UE eNB
EPS Bearer
Radio Bearer S1 Bearer
End-to-end Service
External Bearer
Radio S5/S8
Internet
S1
E-UTRAN EPC
Gi
E-RAB S5/S8 Bearer
Image source: TS 36.300
7/31/2019 3GPP LTE Evolved Packet System
18/43andreas.maeder@neclab.eu
QoS and Policy Control (1/2)
In LTE, QoS is enforced at the granularity of EPS bearers UE PDN GW (for GTP-based EPC)
A EPS beareruniquely identifies traffic flows that receive a commonQoS
A UE always has a Default Bearer, for all flows that do not require anyspecial QoS treatment
Dedicated Bearersare established for all service data flowsthatrequire special QoS treatment
The EPS bearer QoS profile includes the parameters QCI, ARP, GBR QCI: QoS Class Indicator is a reference to access node-specific
parameters that control bearer level packet forwarding
ARP: Allocation and Retention Priority; pre-emption
capability/vulnerability GBR: Guaranteed Bit Rate
QoS over IP Transport (i.e. between eNB and PDN GWs) is for allcases provided based on Differentiated Services (DiffServ) Mapping between EPS QoS Transport-level QoS
18 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
19/43
andreas.maeder@neclab.eu
QoS and Policy Control (2/2)
eNB PDN GWUE
Traffic Flow Aggregates
UL Packet Filter
UL-PF RB-ID
Traffic Flow Aggregates
DL Packet Filter
DL-PF S1-TE-ID
RB-ID S1-TE-ID
Ra
dio Bearer
S1 Bearer
Application / Service Layer
IP Transport Leg
Serving GW
DL Packet Filter
DL-PF TNL QoS
S1-TE-ID TNL QoS
Packet classification can be performed by means of IP-5-tuple, DPI,
PDN GW (GTP) for downlink traffic UE for uplink
Downlink Bearer binding takes place in PDN GW for GTP based EPC
19 BeFemto Winter School 2012
7/31/2019 3GPP LTE Evolved Packet System
20/43
andreas.maeder@neclab.eu
Policy and Charging Control (PCC)
PCEF: Policy and Charging Enforcing Function enforces QoS policies on bearers Decides which traffic is bound to which bearers
Decides to setup dedicated bearers for certain traffic types Located in PDN-GW
PCRF: Provides policies and rules for PCEF
BeFemto Winter School 201220
Gy
Gz
Subscription Profile
Repository
(SPR)
Rx
AFSp
Gx
Offline
Charging
System
(OFCS)Gateway
PCEF
Policy and Charging Rules Function(PCRF)
Online Charging System (OCS)
Service Data Flow
Based
Credit Control
Gxx
BBERF
Provides policiesaccording to
subscription plan
Performs bearerbinding accordingto PCC rules andservice data flow
template
Credit accordingto QoS,
home/visited
network, closed-subscriber group(for HeNBs), time
of day, etc
Image source: TS 23.302
7/31/2019 3GPP LTE Evolved Packet System
21/43
andreas.maeder@neclab.eu
Default Quality of Service Classes
These values are UE-to-PCEF (PDN-GW) QoS values QCI QoS parameters have to be mapped to scheduling and RRMparameters in the eNodeB , such as:
Scheduling delay budget, bandwidth
HARQ and ARQ parameters
BeFemto Winter School 201221
QCI Resource Type PriorityPacket Delay
Budget(NOTE 1)
Packet ErrorLoss
Rate (NOTE 2)Example Services
1
(NOTE 3)
2 100 ms 10-2 Conversational Voice
2(NOTE 3) GBR
4 150 ms 10-3 Conversational Video (Live Streaming)
3(NOTE 3)
3 50 ms 10-3 Real Time Gaming
4(NOTE 3)
5 300 ms 10-6 Non-Conversational Video (Buffered Streaming)
5(NOTE 3)
1 100 ms 10-6 IMS Signalling
6(NOTE 4) 6 300 ms 10-6
Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressivevideo, etc.)
7(NOTE 3)
Non-GBR7 100 ms 10-3
Voice,Video (Live Streaming)Interactive Gaming
8(NOTE 5) 8
300 ms 10-6Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file
9(NOTE 6)
9 sharing, progressive video, etc.)
Source: TS 23.302
7/31/2019 3GPP LTE Evolved Packet System
22/43
andreas.maeder@neclab.eu
QoS and Policy Control Idea and Reality
BeFemto Winter School 201222
The Internet
MNO
Video
CloudsolutionsP-GW/PCCS-GW
dedicated bearer
default EPS bearer
eNBUE
PCC maps Internet trafficto EPS bearers, defines
QoS requirements
eNB performsscheduling accordingto QoS requirements
The Internet
MNO
Video
CloudsolutionsP-GW/PCCS-GW
default EPS bearer
eNBUE
All Internet traffic ismapped to the default
bearer
All Internet traffic istreated in the same way
Ideal case
Reality today
7/31/2019 3GPP LTE Evolved Packet System
23/43
andreas.maeder@neclab.eu
Overview of E-UTRAN
BeFemto Winter School 201223
7/31/2019 3GPP LTE Evolved Packet System
24/43
andreas.maeder@neclab.eu
E-UTRAN Basic principles
Flat architecture if compared to UMTS (no RNC, all radio-related
functions located in eNodeB) Minimize signaling towards EPC X2 interface between eNodeBs for hand-over, neighbor detection,
interference coordination,
Self-organizing network (SON) functions to mitigatemanagement overhead
(Semi-) automatic configuration and optimization, e.g. neighborrelation, RACH optimization, PCI selection, mobility parameteroptimization
Support for hand-overs to other RATs (radio access technologies) GPRS, UMTS CS-fallback, Single Radio Voice Call Continuity (SRVCC)
Support for femtocells (HeNBs)
BeFemto Winter School 201224
7/31/2019 3GPP LTE Evolved Packet System
25/43
andreas.maeder@neclab.eu
E-UTRAN Network Entities
BeFemto Winter School 201225
Image source: TS 36.300
E-UTRAN
E-UTRAN with HeNBsE-UTRAN with relay nodes
EPC
EPC
EPC
7/31/2019 3GPP LTE Evolved Packet System
26/43
andreas.maeder@neclab.eu
Functional Split between E-UTRAN and EPC
Functional split of RAN-related procedures between E-UTRAN andEPC
Everything directly related to radio aspects is located in the E-UTRAN
Management aspects (e.g. mobility management) is located in the EPC
BeFemto Winter School 201226
internet
eNB
RB Control
Connection Mobility Cont.
eNB MeasurementConfiguration & Provision
Dynamic Resource
Allocation (Scheduler)
PDCP
PHY
MME
S-GW
S1
MAC
Inter Cell RRM
Radio Admission Control
RLC
E-UTRAN EPC
RRC
MobilityAnchoring
EPS Bearer Control
Idle State MobilityHandling
NAS Security
P-GW
UE IP addressallocation
Packet Filtering
Source: TS 36.300
S1-MME (control plane) for mobilitymanagement aspectsS1-U (user plane) for user data
transport
7/31/2019 3GPP LTE Evolved Packet System
27/43
andreas.maeder@neclab.eu
LTE PHY/MAC Basic Principles
OFDMA (Orthogonal frequency division multiple access) in downlink
SC-FDMA (Single carrier frequency division multiple access) inuplink DFT-spread OFDMA, lower peak-over-average power ratio (increased
power efficiency, lower cost)
Scalable spectrum use: from 1.4MHz to 20MHz
Localized or distributed resource allocation for frequency selectiveor frequency diverse scheduling
Support for spatial multiplexing (MIMO/MU-MIMO) Frequency and time division duplex for paired and unpaired
spectrum
BeFemto Winter School 201227
Channel bandwidthBWChannel[MHz]
1.4 3 5 10 15 20
Transmission bandwidthconfiguration N
RB
6 15 25 50 75 100
NRB: number of resourceblocks
7/31/2019 3GPP LTE Evolved Packet System
28/43
andreas.maeder@neclab.eu
Frame structure (FDD)
BeFemto Winter School 201228
0 1 2
Frame (10ms)
0 1 2 3 4 5 19
Subframe (1ms)
Slot (0.5ms)
0 1 2 3 64 5
6 or 7 OFDM symbols
cyclic prefixes
Resource Block:6or 7symbols x 12subcarriers
12
subcarriers
Reference symbols
(two antennas)
ResourceElement
Master information block(MIB) in subframe 0 of each
frame for cell acquisition;40ms TTI for MIB
7/31/2019 3GPP LTE Evolved Packet System
29/43
andreas.maeder@neclab.eu
Logical and physical channels
BeFemto Winter School 201229
BCH PCH DL-SCHMCH
Downlink
Physical channels
Downlink
Transport channels
PBCH PDSCHPMCH PDCCH
Uplink
Physical channels
Uplink
Transport channels
UL-SCH
PUSCH
RACH
PUCCHPRACH
CCCH DCCH DTCH
UL-SCHRACH
Uplink
Logical channels
Uplink
Transport channels
BCCHPCCH CCCH DCCH DTCH MCCH MTCH
BCHPCH DL-SCH MCH
Downlink
Logical channels
Downlink
Transport channels
DownlinkUplink
User plane data
7/31/2019 3GPP LTE Evolved Packet System
30/43
andreas.maeder@neclab.eu
LTE RAN Protocol Stack
BeFemto Winter School 201230
Segm.ARQ etc
Multiplexing UE1 Multiplexing UEn
BCCH PCCH
Unicast Scheduling / Priority Handling
Logical Channels
MAC
Radio Bearers
Security Security...
CCCH
MCCH
Multiplexing
MTCH
HARQHARQ
MBMS Scheduling
PCHBCHDL-SCHDL-SCH MCH
RLC
PDCP
ROHC ROHC...
Segm.ARQ etc
...
Transport Channels
Segm.ARQ etc
Security Security...
ROHC ROHC...
Segm.ARQ etc
...
Segm. Segm.
...
...
...
Robust Header Compression
Mapping into LTE resource grid/frame
Cyphering, integrityprotection (control plane)
QoS scheduling
RRC, User plane data, NAS, (GTP-based tunnels)
Ack. Modes,Unack. Mode,
Transparent Mode
7/31/2019 3GPP LTE Evolved Packet System
31/43
andreas.maeder@neclab.eu
Femtocells in LTE/EPS
BeFemto Winter School 201231
7/31/2019 3GPP LTE Evolved Packet System
32/43
andreas.maeder@neclab.eu
Support for Home eNodeBs (HeNBs)
HeNB: A HeNB is a Customer-premises equipment that connects a3GPP UE over EUTRAN wireless air interface to a mobile operators
network using a broadband IP backhaul. Low-power, low-cost eNB with access control and IPsec
Using same, licensed spectrum as macro eNBs
Some requirements on HeNB capabilities (for more see TS 22.220) Operators are in full control of the radio interface of the HeNB
Operators must be able to locate HeNBs to check conformance withregulations
Operators can configure the HeNB, but configuration efforts should be
minimized HeNBs support access control in open, closed or hybrid access mode
UEs should display the CSG type and the HeNB name
User should be able to scan for available HeNBs and manually select
Integrityof the HeNB must be validated before communication
BeFemto Winter School 201232
H NB A hi
7/31/2019 3GPP LTE Evolved Packet System
33/43
andreas.maeder@neclab.eu
HeNB Architecture
HeNB is connected via S1-U/S1-MME to the EPC (i.e. to S-GW andMME)
Optional HeNB-GW serves as concentrator for control plane date HeNB appears as MME towards HeNB, as eNB towards MME
Security GW (SeGW) for IPSec tunnel management HeNB Management system for OA&M tasks (software updates, etc)
HeNBGW
EPC
SeGW
HeNB
HeNB MgmtSystem
S1-MME
S1-U
S1-MME
S1-U
HeNB
S1-MME
S1-MME
S1-U S1-U
X2
eNB
S1-U
S1-MME
BeFemto Winter School 201233
Since rel. 10
Optional in
EPS
H NB A C l
7/31/2019 3GPP LTE Evolved Packet System
34/43
andreas.maeder@neclab.eu
HeNB Access Control
Three types of access modes: open, closed and hybrid Closed Subscriber Group (CSG): List of UEs which are allowed to access a HeNB
Each CSG has a CSG identity (CSGID) Access control is based on two lists:
Allowed CSG List (ACL): CSGIDs maintained by the user (e.g. via web)
Operator CSG List (OCL): pre-provisioned list of CSGIDs by the operator
CSGID and access mode is broadcasted by HeNB
BeFemto Winter School 201234
MMEUE
ACL
USIM
Stored, if files are present
NAS signaling (e.g. Attach,Detach, TAU, ServiceRequest) e.g. with manualCSG selection
ACL
Infor-mation
check
HSS
Insert & PurgeSubscr. Data(Attach /Detach /Relocation)
includes exp.time
Home-eNB
CSG-ID
CSG-ID,CSGaccessmode
User display,select
OCL OCL
Copy ofoperatorCSG list
CopyofACL
CSGServerOMA DM /
OTA
M bilit NB H NB
7/31/2019 3GPP LTE Evolved Packet System
35/43
andreas.maeder@neclab.eu
Mobility: eNB->HeNB
BeFemto Winter School 201235
UE MMESource
eNB
HeNB
GW*Target
HeNB
1. Reconfiguration
(Report Proximity Config)2. Proximity Indication
3. Reconfiguration
(Measurement Config)
4. Measurement Report(PCI)
5. Reconfiguration(SI Request)
6. BCCH (CGI, TAI, CSG ID)
7. Measurement Report(CGI, TAI, CSG ID, Member
Indication) 8. HO Required
(Access Mode*, CSG ID*)
10. HO Request(CSG ID*, Membership Status*)
9. Access control based onreported CSG ID
11. HO Request(CSG ID*, Membership Status*)
12. Validate CSG ID
13. HO Request Ack
14. HO Request Ack
15. HO Command
16. HO Command
If target HeNB is in CSG
whitelist
problem: PCI confusion if more than one HeNBs withthe same PCI in the source eNB coverage area
Therefore UE has to obtain system information (SI)
Before Rel.10: S1-based hand-overs
Cell global identifier, tracking area id., CSG ID
I t f di ti
7/31/2019 3GPP LTE Evolved Packet System
36/43
andreas.maeder@neclab.eu
Interference coordination
1. Interference avoidance based on carrier aggregation (CA)
Division of spectrum in primary and secondary component carriers (PCC,
SCC)one PCC for each network layer (e.g. macro/femto) No control channel interference between layers
2. Time-division multiplexing with almost blank subframes (ABS) Subframes are muted out (with exception of common RS, synch, PBCH)
UE can hear macro cells during ABS. But: high interference variations.
BeFemto Winter School 201236
f1
f2
f1
f2
control
data
Macro
Femto
Macro
Femto
LIPA d SIPTO
7/31/2019 3GPP LTE Evolved Packet System
37/43
andreas.maeder@neclab.eu
LIPA and SIPTO
Current 3G (and LTE) architecture is not optimized for high-volumedata communications
Main Problem:
Todays mobile networksare highly centralized:
Central gateways handleall mobile traffic
All traffic needs to betunnelled to the core
No caching support at
network edge
Transport and Mobile Coreinfrastructure becomes a bottleneckat central locations
BeFemto Winter School 201237
eNB
eNBeNB
Service
Infrastructure
(e.g. AS, Content
Servers/Caches)
Network
Infrastructure (e.g.
Mobility Anchor)
DSL/Cable Modem
IP Edge Node
HomeGW
Network resource andprocessingbottleneck
LIPA L l IP A
7/31/2019 3GPP LTE Evolved Packet System
38/43
andreas.maeder@neclab.eu
LIPA Local IP Accesss
With LIPA, UEs connected to a HeNB are able to access the localIP network (just like with WiFi APs)
Problem: mobility connection will be lost with outgoing HO
BeFemto Winter School 201238
L-GW (local GW)mini-PDN-GW
SIPTO S l ti IP T ffi Offl d
7/31/2019 3GPP LTE Evolved Packet System
39/43
andreas.maeder@neclab.eu
SIPTO Selective IP Traffic Offload
Operators want to offload certain traffic from their core network
Realized by local breakout gateways (L-GWs) Traffic is moved to the network edges
BeFemto Winter School 201239
eNB
eNBeNB
Route Optimization
Local Breakout
DSL/Cable Modem
IP Edge Node
Home
GW
Local AccessMobile & Fixed
Backhaul
Indoor & Outdoor
Femtocells (Small Cells)
(Mobile) Cloud
Network Infrastructure
Fixed Mobile
Convergence
7/31/2019 3GPP LTE Evolved Packet System
40/43
andreas.maeder@neclab.eu
Outlook on LTE-Advanced and beyond
BeFemto Winter School 201240
Some Hot topics in 3GPP for LTE Advanced
7/31/2019 3GPP LTE Evolved Packet System
41/43
andreas.maeder@neclab.eu
Some Hot topics in 3GPP for LTE-Advanced
Heterogeneous networks Mobility enhancements for HetNets
Challenge: when to hand-over; how to acquire mobility-relevant information Enhanced (and further enhanced) inter-cell interference coordination (eICIC)
Carrier aggregation Simultaneous use of several component carriers (CC)
E.g. 2x20Mhz in DL, 10 MHz in UL
Challenges for synchronization, MAC control, deployment, planning, Machine-type communication (MTC): M2M traffic has different
characteristics and requirements
Optimization in core and RAN for small messages from many devices
Mobility optimizations
Interfaces towards M2M operators
User plane congestion control Fine-granular traffic management in congested scenarios
Coordinated Multi-Point transmission (CoMP)
BeFemto Winter School 201241
7/31/2019 3GPP LTE Evolved Packet System
42/43
7/31/2019 3GPP LTE Evolved Packet System
43/43