lte overview 110913 day1 v3

8/12/2019 LTE Overview 110913 Day1 v3

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2013 Nokia Solutions and Networks. All rights reserved.

Exploring LTEDay 1

11-12 th Sep 13


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Contents

Day 1 LTE Overview LTE Architecture LTE Interfaces and Protocols LTE Air Interface

OFDMA and SC- FDMA Frame Structure

MIMO Air Interface Channels and Protocols LTE EPS Session Management LTE Mobility Aspects LTE Network Planning


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Contents

Day 2 LTE Signaling

LTE Procedures Parameters

KPIs and Counters NSN LTE solution approach

Radio Transport Core

LTE Key Features


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Contents


OFDMA and SC- FDMA Frame Structure

MIMO Air Interface Channels and Protocols LTE EPS Session Management LTE Mobility Aspects LTE Network Planning


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Mobile broadband traffic more than doublesevery year, Video traffic dominates since 2011


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Motivation for LTEThe Communications Service Provider view

Source: Light Reading (adapted)Voice dominated Data dominated

Traffic volume

Revenue

Time

Network cost (LTE)

Network cost(existing technologies)

Profitability

LTE reduces the cost/Mb

LTE improves

user experience

Mobile network

traffic and costs


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Motivation for LTESubscriber view: better broadband experience

Broadbandeverywhere

LTEon low

frequencybands, e.g.digital dividend

High-SpeedBroadband

Capacity forall

LTE

on largefrequency bands,e.g. 2.6GHz

10-20ms latency100 Mbps peak data rate

already with initial devices


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Main LTE Requirements [3GPP TS25.913]

Peak data rates of uplink/downlink 50/100 Mbps Reduced Latency:

Enables round trip time


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Standardisation bodies around LTE

Next Generation Mobile Networks . Is a group of mobileoperators to share, assess, and drive aspects of mobilebroadband technologies focusing on LTE & EPC (EvolvedPacket Core) and its evolution .More in www.ngmn.org

Collaboration agreement established in December1998. The collaboration agreement brings together anumber of telecommunications standards bodies: ARIB,CCSA, ETSI, ATIS, TTA, and TTC.More in www.3gpp.org

LTE/SAE Trial Initiative . The LTE/SAE Trial Initiative (LSTI)is a global collaborative technology trial driven by vendorsand network operator focused on accelerating the availabilityof commercial and inter-operable next generation LTE mobilebroadband systems.More in http://www.lstiforum.com/

LSTI
http://www.ngmn.org/http://www.3gpp.org/http://www.lstiforum.com/http://www.lstiforum.com/http://www.3gpp.org/http://www.ngmn.org/


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TD-LTE specific Initiative : GTI

Founded by leading mobile network operators in 2011.

Global TD-LTE Initiative (GTI) is a virtual open platform toadvocate co-operation among global operators to promote TD-LTE.

GTI is formed to create value for stakeholders across the TD-LTEecosystem for early adoption of the technology and convergenceof TD-LTE and LTE FDD.

GTI organizes a series of activities to bring operators andvendors together for sharing development strategies andtechnology know-how, expediting the development of terminalsand fostering of global roaming and low-cost terminals, etc

More info http://www.lte-tdd.org/
http://www.lte-tdd.org/http://www.lte-tdd.org/http://www.lte-tdd.org/http://www.lte-tdd.org/


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3GPP LTE Background (1/2)Milestones

End 2004 3GPP workshop on UTRAN Long Term Evolution March 2005 Study item started December 2005 Multiple access selected March 2006 Functionality split between radio and core agreed September 2006 Study item closed & approval of the work items December 2007 1st version of all radio specs approved

March 2008 3GPP Release 8 Stage 1 specifications were frozen December 2008 3GPP freeze of LTE as part of Release 8 (exceptionsfor the EPC to be completed until March2009)

2005 2006 2007 2008

Feasibilitystudy started

Multipleaccess

selected

Feasibilitystudy closed

Work itemstarted

Work planapproved

Stage 2approved

Stage 3approved

Radio Specsapproved


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3GPP LTE Background (2/2)Schedule

2009 Start of Customer Trials March 2009 Ratification of 3GPP Release 8: LTE standardization is completed and approved by 3GPP Release 8 supporting FDD and

TDD modes with the same specification and hardware components

2010 3GPP Release 9 gets ready. Self-organised networks 2011 3GPP Release 10 gets ratified (LTE A) 2012 3GPP Release 8 networks deployments for TDD

2008 2009 2010 2011

DemonstrateLTE AirInterface

Performance

Operator Trials.Friendly-usenetworks

LTE NetworksLaunch:

commercialsolution

available(3Q2010)

Large Scale LTENetworks.

VoIP serviceoptimized.


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LTE OverviewMarket Trends


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Why LTE?Superior mobile broadband user experience

GSM HSPA+

LTE

Throughput latency

GSM HSPA+ LTE

10ms

100 Mbps 150ms

380 million LTE subscribersby 2015

Forecast for LTE lead markets by Research andMarkets

Technology convergence

GSM

WCDMA

CDMA

WiMAX

TD-SCDMA

FDDLTE

TD-LTE

LTEAdvanced>90% harmonizedin 3GPP

Extensive range of radio spectrum support

23 different FDD frequency band options11 different TDD frequency band options

+ new ones still being specifiedboth for new

band deployment and re-farmingcases


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LTE in 2012

continuing in 2013


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Worldwide LTE Footprints


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LTE Network Deployments


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TDD LTE Presence


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Global TDD LTE Networks


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LTE Operating Bands

LTE TDDbands

LTE FDDbands


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Spectrum used in LTE FDD deployments


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Mobile Subscriptions by Technology


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LTE Subscriptions


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Worldwide LTE Subscribers Key Operators

Source Infonetics Research

As of Ju ne 30, 2013 (2Q13)


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LTE Regional Subscriptions Share: Q1 2013


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LTE User Segmentation


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LTE Device Update

Multi-band, multi-mode LTE dongles and CPEs are commercially available from allmajor chipset and device manufacturers.Most of the 948 LTE user devices confirmed by GSA are Category 3 as defined by the3GPP standard40 Category 4 devices are available, in most form factors


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TDD LTE Devices

Bands 38 (2.6 GHz) and 40 (2.3 GHz) have the largest ecosystems of TDLTE user devices.


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What are the LTE challenges?

Best price, transparent flat rate Full Internet Click-bang responsiveness

reduce cost per bit provide high data rate provide low latency

The Users expectation ..leads to the operators challenges

Netwok challenges Backhaul Devices availability Interoperability

LTE: lower cost per bit and improved end user experience


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Contents

Day 1 LTE Overview

LTE Architecture LTE Interfaces and Protocols LTE Air Interface

OFDMA and SC- FDMA Frame Structure MIMO

Air Interface Channels and Protocols LTE EPS Session Management LTE Mobility Aspects LTE Network Planning


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Evolution Path to LTEOperator migration paths to LTE

Enabling flat broadband architecture

TDSCDMAGSM /

(E)GPRS

LTE

CDMA

I-HSPA

WCDMA /HSPA

>90 % of world radio access market migrating to LTE

TD-LTE

WiMaX


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Network Architecture Evolution

S- GW + P-GWGGSN

SGSN

RNC

Node B(NB)

Direct tunnel

GGSN

SGSN

I-HSPA

MME

HSPA R7 HSPA R7 LTE R8

Node B +RNC

Functionality

EvolvedNode B(eNB)

GGSN

SGSN

RNC

Node B(NB)

HSPA

HSPA R6

LTE

User planeControl Plane

Flat architecture : single network element in userplane in radio network and core network

LTE/EPC N k A hi


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LTE/EPC Network Architecture

Main references to architecture in 3GPP specs: TS23.401,TS23.402,TS36.300

Evolved UTRAN (E-UTRAN)

MME S10

S6a

ServingGateway

S1-U

S11

PDNGateway

PDN

Evolved Packet Core (EPC)

PCRFGx Rx

SGiS5/S8

HSS

MobilityManagement

Entity Policy &Charging Rule

Function

S-GW /P-GWLTE-UE

Evolved Node B(eNB)

X2

LTE-Uu

eNB


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LTE Interworking with 2G/3G Networks


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LTE Interworking with 3G Alternative


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EPC Network Elements (1/2)MME: Mobility Management Entity Pure signalling entity inside the EPC:

Signalling coordination for EPC bearer setup/release Subscriber attach/detach Tracking area updates Roaming Control Trigger and distribution of paging messages to UE

Security control Authentication, integrity protection

Serving Gateway Manages the user data in the EPC

Receives packet data from the eNodeB and sends packet data to it

HSSeNB

MME

ServingGateway

S1-U

S1-MME

S11S6a


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EPC Network Elements (2/2)

Packet Data Network Gateway Connection between EPC and a number of external data networks (comparable

to GGSN in 2G/3G networks) IP Address Allocation for UE Packet Routing/Forwarding between

Serving GW and external Data Network Packet screening (firewall functionality)

Policy and Charging Rule Function Quality of Service (QoS) negotiation with the external PDN Charging Policy: How packets should be accounted

HSS: Home Subscriber Server Permanent and central subscriber database Stores mobility and service data for every subscriber Contains AuC (authentication center) functionality

MME

ServingGateway

S5/S8

PDNGateway

PDNSGi

PCRFS7 Rx+

S11HSS

S6a


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Inter-cell RRM: HO, load balancing between cells

Radio Bearer Control: setup , modifications andrelease of Radio Resources

Connection Mgt. Control: UE State Management,MME-UE Connection

Radio Admission Control

eNode B Meas. collection and evaluation

Dynamic Resource Allocation (Scheduler)

eNB Functions

IP Header Compression/ de-compression

Access Layer Security: ciphering and integrityprotection on the radio interface

MME Selection at Attach of the UE

User Data Routing to the S-GW/ P-GW

Transmission of Paging Msg coming from MME

Transmission of Broadcast Info (e.g. System info,MBMS)

Only network element defined aspart of eUTRAN

Replaces the old Node B / RNCcombination from 3G.

Provides all radio managementfunctions

To enable efficient inter-cell radiomanagement for cells not attachedto the same eNB, there is a inter-eNB interface X2 specified. It willallow to coordinate inter-eNBhandovers without direct involvementof EPC during this process.

Evolved Node B (eNB)


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Main references to architecture in 3GPP specs: TS23.401,TS23.402,TS36.300

Evolved UTRAN (E-UTRAN)

MME S10

S6a

ServingGateway

S1-U

S11

PDNGateway

PDN

Evolved Packet Core (EPC)

PCRFGx Rx

SGiS5/S8

HSS

MobilityManagement

Entity Policy &Charging Rule

Function

S-GW /P-GWLTE-UE

Evolved Node B(eNB)

X2

LTE-Uu

eNB

LTE R di I f d h X2 I f


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LTE Radio Interface and the X2 Interface

LTE-Uu interface Air interface of LTE

Based on OFDMA in DL and SC-FDMA inUL

FDD and TDD duplex methods Scalable bandwidth 1.4MHz to currently

20 MHz

X2 interface Inter eNB interface X2AP: special signalling protocol Functionalities:

In inter- eNB HO to facilitate handoverand provide data forwarding.

Provides load information toneighbouring eNBs Logical interface: It does not need direct

site-to-site connection

(E)-RRC User PDUs User PDUs

PDCP

..

RLC

MAC

LTE-L1 (FDD/TDD-OFDMA/SC-FDMA)

TS 36.300

eNB

LTE-Uu

eNB

X2

User PDUs

GTP-U

UDP

IPL1/L2

TS 36.424

X2-UP(User Plane)X2-CP

(Control Plane)

X2-AP

SCTP

IPL1/L2TS 36.421

TS 36.422

TS 36.423

TS 36.421

TS 36.420[currently also in TS 36.300]

S1 MME & S1 U I f


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S1-MME & S1-U Interfaces

S1-MME interface Control interface between eNB and

MME S1AP:S1 Application Protocol MME and UE will exchange non-

access stratum signaling via eNBthrough this interface (i.e.authentication, tracking area updates)

S1-U interface

User plane interface between eNB andserving gateway Pure user data interface (U=User plane)

MME

ServingGateway

S1-MME(Control Plane)

S1-U

(User Plane)

NAS Protocols

S1-AP

SCTP

IP

L1/L2

User PDUs

GTP-U

UDP

IP

L1/L2

TS 36.411

TS 36.411

TS 36.412

TS 36.413

TS 36.414

TS 36.410[currently in TS 36.300]

eNB

S1 interface is divided into two parts:

S10 d S6 i f


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S10 and S6a interfaces

S10

Interface between different MMEs Used during inter-MME tracking area

updates It is a pure signaling interface, no user

data runs on it

S6a

Interface between the MME and theHSS The MME uses it to retrieve

subscription information from HSSduring attach

S11 d S5/8 i f


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S11 and S5/8 interface

S11 Interface between MME and SGW

A single MME can handle multipleServing GWs, each one with itsown S11 interface

Used to coordinate theestablishment of SAE bearerswithin the EPC.

S5/S8 Interface between SGW and

PGW S5: If Serving GW and PDN GW

belong to the same network (non-roaming case)

S8: Roaming case, mainly usedto transfer user packet databetween PDN GW and SGW

S7 d SGi I t f


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S7 and SGi Interface

S7> Interface between PGW and PCRF

> It allows the PCRF to request thesetup of a SAE bearer withappropriate QoS

> To indicate profile changes to thePCRF to apply a new policy rule.

SGi> Interface used by the PDN GW to

send and receive data to and from theexternal data network> It is either IPv4 or IPv6> This interface corresponds to the Gi

interface in 2G/3G networks

S3 d S4 I t f


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S3 and S4 Interface

S3/S4> Interfaces between EPC and 2G/3G packet switched core network domain> They would allow inter-system changes between SAE and 2G/3G> The S3 is a pure signaling interface used to coordinate the inter-system change between

MME and SGSN> The S4 is the user plane interface and it is located between SGSN and Serving GW


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S9 Interface


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S9 Interface

S9> Interface between the hPCRF and the vPCRF used in roaming cases.> To retrieve QoS profile from hPCRF to vPCRF

SCTP

IP

L1/L2

DIAMETER

S9 Application

hPCRF

S9(Control Plane)

vPCRF

TS 29.215

Charging Architecture Non Roaming


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Charging Architecture Non Roaming

Charging Architecture


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Charging Architecture

> Charging for LTE/SAE is performed on a per IP bearer basis.

> The network elements involved in LTE/SAE charging are:> The PCRF for charging rule instructions

> The PDN GWs Policy & Charging Enforcement Function (PCEF) with its collectionand credit control client functions,

> The Serving GW with its collection functions for interoperator charging.

> The Charging Gateway Function (CGF), collecting CDR for offline charging.> The Online Charging Function (OCS), containing credit information for online

charging.

> The Billing System (BS)

Gy Interface


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Gy Interface

SCTP

IP

L1/L2

DIAMETER

DCCA

Gy(based on Diameter)

OCS

TS 32.299

PDNGateway

PCEF

Gy Interface between the P-GW and the Online Charging System (OCS) OCS is used for flow based charging information transfer. The Gy interface uses Diameter Credit-Control application (DCCA), as

defined in IETF RFC 4006

LTE/SAE Roaming Architecture Case 1


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LTE Interworking with non 3gpp Access


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LTE Interworking with non 3gpp Access

Contents


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Contents

Day 1 LTE Overview





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LTE Air InterfaceOFDM Concepts

Multiple Access

1 2 3UE 1 UE 2 UE 3 4 UE 4 UE 55


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Multiple Access

1 2 3 4 5

2

12345

4 2

1

23

45

31

15

53

3

24

1

P o w e r

Frequency

TDMATime Division

MultipleAccess,

2G e.g. GSM,PDC

FDMAFrequency

DivisionMultipleAccess

1G e.g. AMPS,NMT, TACS

CDM

Code DivisionMultiple Access3G e.g. UMTS,

CDMA2000

1 2 3UE 1 UE 2 UE 3 4 UE 4 UE 55

OFDMAOrthogonalFrequency

DivisionMultiple Access

e.g. LTE

OFDM Technology


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OFDM TechnologyOFDM stands for Orthogonal Frequency Division Multiplexing

OFDM is a multicarrier transmission technique which is based on FDM. The maindifference between single carriers system and OFDM relates to how the informationis mapped onto many separately modulated carriers

FDM System: FDM system utilizes multiple frequencies to simultaneously transmit multiple signals inparallel

OFDM System: OFDM uses the similar concept as FDM but increases the spectral efficiency by enablingthe spacing between subcarriers to be reduced untill they are effectively overlapping. This can be done sinceOFDM utilizes subcarrier frequencies which are orthogonal

OFDM


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OFDM[+] Advantages: The cancellation of inter-symbol interference makes more complex the

hardware design of the receivers. In WCDMA for instance the RAKE receiverrequires a huge amount of DSP capacity with high data rate. OFDM makes theISI cancellation more easy.

OFDM makes the radio interface more robust Easy for system design with IFFT/FFT, low cost Flexible for resource selection on Frequency domain

[-] Disadvantage: OFDM system has high requirement on time

and frequency synchronization High PAPR

Multicarrier Transmission and Reception


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Multicarrier Transmission and Reception

Use of IFFT and FFT in generating OFDM Signal


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Use of IFFT and FFT in generating OFDM Signal

OFDM Basics (I)


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OFDM Basics (I)

Transmits hundreds or even thousands of separately modulated radio signals

using orthogonal subcarriers spread across a wideband channel

Orthogonality:

The peak (centrefrequency) of onesubcarrier

intercepts thenulls of theneighbouringsubcarriers

15 kHz in LTE: fixed

Total transmission bandwidth

OFDM Basics (II)


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OFDM Basics (II)

Data is sent in parallel across the set of subcarriers, each subcarrier onlytransports a part of the whole transmission

The throughput is the sum of the data rates of each individual (or used) subcarrierswhile the power is distributed to all subcarriers

FFT (Fast Fourier Transform) is used to create the orthogonal subcarriers. Thenumber of subcarriers is determined by the FFT size (by the bandwidth)

Power

frequency

bandwidth

Challenges for the Air Interface Design


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The usage of the pulse leads to other challenges to be solved:

1. ISI = Intersymbol InterferenceDue to multipath propagation

2. ACI = Adjacent Carrier InterferenceDue to the fact that FDM = frequency division multiplexing willbe used

3. ICI = Intercarrier Interference

Losing orthogonality between subcarriers because of effectslike e.g. Doppler

What should be the solutions to these challenges? (see next slides)

OFDM and Multipath


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OFDM and Multipath

Multipath causes Inter Symbol Interference (ISI) which affects the subcarrierorthogonality due to phase distortion

Solution to avoid ISI is to introduce a Guard Period (Tg) after the pulse Tg needs to be long enough to capture all the delayed multipath signals To make use of that Tg (no transmission) Cyclic Prefix is transmitted

4

time

TsTime Domain

time

time

Tg

1

2

3

time

When the delayspread of the multi-path is greater thanthe guard periodduration (Tg) there isinter-symbolinterference (ISI) 4

12

3

Cyclic Prefix (CP) and Guard Time


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Cyclic Prefix (CP) and Guard Time

Note: CP represents anoverhead resulting in symbolrate reduction.

Having a CP reduces thebandwidth efficiency but thebenefits in terms of minimisingthe ISI compensate for it

t

total symbol time T(s)

Guard Time

T(g)

CPT(g)

Useful symboltime T(b)

Consists in copying the last part of a symbol shape for a duration of guard-timeand attaching it in front of the symbol

CP needs to be longer than the channel multipath delay spread. A receiver typically uses the high correlation between the Cyclic Prefix (CP) and

the last part of the following symbol to locate the start of the symbol and beginthen with decoding

2 CP options in LTE: Normal CP: for small cells or with short multipath delay spread Extended CP: designed for use with large cells or those with long delay profiles

OFDM: Orthogonal Frequency Division Multi-Carrier


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O D : O t ogo a eque cy D v s o u t Ca e

OFDM allows a tight packing of small carrier - called thesubcarriers - into a given frequency band.

No ACI (Adjacent Carrier Interference) in OFDM

due to the orthogonal subcarriers !

P o w e r

D e n

s i t y

P o w e r

D e n s

i t y

Frequency (f/fs) Frequency (f/fs)

SavedBandwidth



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g g

The usage of the pulse leads to other challenges to be solved:

1. ISI = Intersymbol InterferenceDue to multipath propagation solution: use cyclic prefix

2. ACI = Adjacent Carrier Interference

Due to the fact that FDM = frequency division multiplexingwill be used

solution: orthogonal subcarriers

3. ICI = Intercarrier InterferenceLosing orthogonality between subcarriers because of effectslike e.g. Doppler solution: use reference signals will be explained later

Different Methods for OFDM Multiple Access


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.

.

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Plain OFDM

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Time Division Multiple Accesson OFDM

time

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OFDMA is registered trademark of Runcom Technologies Ltd.

1 1 1

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.

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2

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2...

3 33 3 3

.

.

.

.

.

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Plain Orthogonal FrequencyMultiple Access

OFDMA

time

...

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1 1

1 1 1 1

2 22

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13 33 3 3

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Orthogonal FrequencyMultiple Access

OFDMA

time

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s u

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3 3 3

33 3 3 3

3

Resource Block (RB)1 2 3 common info(may be addressed via HL)UE 1 UE 2 UE 3

p

OFDMA Parameters


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Frame duration: 10ms created from slots and subframes Subframe duration (TTI): 1 ms (composed of 2x0.5ms slots)

Subcarrier spacing: Fixed to 15kHz Sampling Rate: Varies with the bandwidth but always factor ormultiple of 3.84 to ensure compatibility withWCDMA by using common clocking

Frame Duration

Subcarrier Spacing

Sampling Rate (MHz)

Data Subcarriers

Symbols/slot

CP length

1.4MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

10 ms

15 kHz

Normal CP=7, extended CP=6

Normal CP=4.69/5.12 sec, extended CP= 16.67sec

1.92 3.84 7.68 15.36 23.04 30.72

72 180 300 600 900 1200

10ms

Peak-to-Average Power Ratio in OFDMA


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g

The transmitted power is the sum of thepowers of all the subcarriers

Due to large number of subcarriers, thepeak to average power ratio (PAPR)tends to have a large range

The higher the peaks, the greater therange of power levels over which thepower amplifier is required to work

Having a UE with such a PA that worksover a big range of powers would beexpensive

Not best suited for use with mobile(battery-powered) devices

SC-FDMA and OFDMA


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OFDMA transmits data in parallel across multiple subcarriers SC-FDMA transmits data in series employing multiple subcarriers

In the example: OFDMA: 6 modulation symbols (01,10,11,01,10 and 10) are transmitted per OFDMA

symbol, one on each subcarrier SC-FDMA: 6 modulation symbols are transmitted per SC-FDMA symbol using all

subcarriers per modulation symbol. The duration of each modulation symbol is 1/6 th of themodulation symbol in OFDMA

OFDMA SC-FDMA

SC-FDMA and OFDMA


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LTE Air InterfaceFrame Structure

LTE Physical Layer Structure Frame Structure


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(FDD) FDD Frame structure ( also called Type 1 Frame ) is common to both uplink and

downlink. Divided into 20 x 0.5ms slots

Structure has been designed to facilitate short round trip time

10 ms frame

0.5 ms slot

s0

s1

s2

s3

s4

s5

s6

s7

s 18 s 19..

1 ms sub-frame

SF 0 SF 1 SF 2 SF 9..

sy 4sy 0 sy 1 sy 2 sy 3 sy 5 sy 6

0.5 ms slot

SF 3

- Frame length =10 ms- FDD: 10 ms sub-frame for UL

and 10 ms sub-frame for DL

- 1 Frame = 20 slots of 0.5ms each- 1 slot = 7 ( normal CP) or 6

symbols ( extended CP)

SF: SubFrame

s: slot

Sy: symbol

LTE Physical Layer Structure Frame Structure


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Presentation / Author / Date

(TDD) Frame Type 2 : similar in time-domain to FDD but with some specific fields to

enable also TD-SCDMA co-existence (China)

A radio frame (10ms) contains 2 half frames of 5ms each Two switching point periodicities: 5m or 10 ms Each half frame carries 5 subframes Subframes 1 and 6 are special subframes and consist of three specialised fields

inherited from TD-SCDMA with configurable lengths subject to a total of 1ms

Subframes 0, 5 and DwPTS are always reserved for downlink Subframes 2, 7 and UpPTS are reserved for uplink in case 5 ms switch-pointperiodicity

Remaining fields are dynamically assigned between UL and DL

DwPTS: Downlink Pilot time Slot

UpPTS: Uplink Pilot Time SlotGP: Guard Period to separate between UL/DL

UL/DL Configurations ( TDD)


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78

TDD allows for flexible bandwidth allocation between uplink and downlink tosupport asymmetric traffic The number of subframes dedicated to uplink and downlink within the 10ms frame can be

adjusted7 different frame configurations

Chosen UL/DL Configuration should be the same across all cells of a network to avoidinterference between transmission directions

NSNs first TD release (RL15TD) supports Configuration 1 and 2 only. Configuration1 provides almost 1:1 UL-to-DL ratio

Special Subframe Configuration (TDD)


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79

Total length of special subframe is 1ms but the length of the each field may vary 9 different formats supported NSNs first TD release supports formats 5 and 7

Fields : Downlink Pilot time Slot

A regular shortened downlink subframe Contains reference signals and control information It may carry data at discretion of the scheduler

Contains PSS (note: SSS is transmitted on the last symbol of subframe 0) Uplink Pilot Time Slot

Mainly used for RACH transmission Guard Period

Switching point between downlink and uplink transmission

Compensates for the delay when switching between transmission directions Its length determines the maximum supportable cell size

SUBFRAME 1

Subframe structure and CP length


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80


80

Normal cyclic prefix:

Extended cyclic prefix:

Copy= Cyclic prefix

= Data

5.21 s

16.67 s

Subframe length is 1 ms for all bandwidths A Subframe contains 2 slots. The slot length is 0.5 ms Slot carries 7 symbols with normal CP or 6 symbols with extended CP. The

length of the CP depends on the symbol position within the slot: Normal CP: symbol 0 in each slot has a CP length of = 160 x Ts (5.21 s) and

remaining symbols have a CP length of = 144 x Ts (4.7 s) Extended CP: CP length for all symbols in the slot is 512 x Ts (16.67s)

Ts: sampling time of theoverall channel. Basic TimeUnit

Ts =1 sec

Subcarrier spacing X max FFT size

Ts = 32.5nsec

Normal and Extended Cyclic Prefix


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81


81

Normal Cyclic Prefix

160 Ts 144 Ts

2048 Ts

Ts = 1/30720 msCyclic Prefix

144 Ts 144 Ts 144 Ts 144 Ts 144 Ts

2048 Ts 2048 Ts 2048 Ts 2048 Ts 2048 Ts 2048 Ts

7 2048 Ts+ 6 144 Ts+ 1 160 Ts

15360 Ts = 0.5 ms

Main Body

512 Ts 512 Ts

2048 Ts

Ts = 1/30720 ms

Cyclic Prefix

512 Ts 512 Ts 512 Ts 512 Ts

2048 Ts 2048 Ts 2048 Ts 2048 Ts 2048 Ts

6 2048 Ts+ 6 512 Ts

15360 Ts = 0.5 ms

Main Body

Extended Cyclic Prefix


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Resource Element


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83


83

Theoretical minimum capacity allocation unit

Equivalent to one subcarrier x one symbol period 72 or 84 Resource Elements per Resource Block Each Resource Element can accommodate 1 modulation symbol, e.g. 2

bits for QPSK, 4 bits for 16QAM and 6 bits for64 QAM Modulation symbol rate per Resource Block is 144 ksps or 168 ksps

Case 1: Normal Cyclic Prefix Case 2: Extended Cyclic Prefix

7 symbols = 0.5 ms 6 symbols = 0.5 ms

F r e q u e

n c y

D o m a

i n

1 2 s u

b c a r r i e r s =

1 8 0 k H z

Resource Element

1 2 s u

b c a r r

i e r s =

1 8 0 k H z

Time Domain Time Domain

Modulation Schemes


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84


84

b 0 b 1

QPSK

Im

Re10

11

00

01

b 0 b 1b 2b 3

16QAM

Im

Re

0000

1111

Im

Re

64QAM

b 0 b 1b 2b 3 b 4 b 5

3GPP standard defines the following options: QPSK,16QAM, 64QAM in both directions (UL and DL) UL 64QAM not supported in RL15TD

Not every physical channel is allowed to use anymodulation scheme:

Scheduler decides which form to use depending on carrierquality feedback information from the UE

QPSK:

2 bits/symbol

16QAM:

4 bits/symbol

64QAM:

6 bits/symbol

Physicalchannel

Modulation

PDSCH QPSK,16QAM,64QAM

PMCH QPSK,16QAM,64QAM

PBCH QPSKPDCCH

(PCFICH,)

QPSK

PUSCH QPSK,16QAM,64QAM

PUCCH BPSKand/orQPSK

PHICH BPSK

Modulation and TB Size


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85


85

DL MCSsMCS I TBS MCS_index Mod order

0-QPSK 0 0 21-QPSK 1 1 22-QPSK 2 2 2

3-QPSK 3 3 24-QPSK 4 4 25-QPSK 5 5 26-QPSK 6 6 27-QPSK 7 7 28-QPSK 8 8 29-QPSK 9 9 2

10-16QAM 9 10 411-16QAM 10 11 4

12-16QAM 11 12 413-16QAM 12 13 414-16QAM 13 14 415-16QAM 14 15 416-16QAM 15 16 417-64QAM 15 17 618-64QAM 16 18 619-64QAM 17 19 620-64QAM 18 20 6

21-64QAM 19 21 622-64QAM 20 22 623-64QAM 21 23 624-64QAM 22 24 625-64QAM 23 25 626-64QAM 24 26 627-64QAM 25 27 628-64QAM 26 28 6

From TS 36.213 (DL example shown here)

MCS index -> from 0 to 28 -> it is decided bythe scheduler which should translate a specificCQI in an MCS index

Modulation Order -> indicates the modulationtype (QPSK, ) by indicating the number of bitsper symbolQPSK = 216QAM = 464QAM = 6

ITBS = TBS indexThe TBS Index is mapped to a specific TBS sizefor a specific #RBsUses a different table


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86


86

LTE Air InterfaceMIMO

Multiple-Input Multiple-Output MIMO Principle


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87


Tm

T2

T1

Rn

R2

R1

Input

M x NMIMOsystem

Output

MIMO: Multiple-Input Multiple Output M transmit antennas, N receive antennas form MxN MIMO system huge data stream (input) distributed toward m spatial distributed

antennas; m parallel bit streams (Input 1..m) Spatial Multiplexing generate parallel virtual data pipes using Multipath effects instead of mitigating them

Signal from j th Tx antenna

S j

MIMOProcessor

MIMO Principle (2/2)


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88


Tm

T2

T1

Rn

R2

R1

MIMOProcessor

Input

M x NMIMO

Output

h 1,1h 2,1h n,1

h n,2

h n,m

h 2,2h 2,m

h1,mh 1,2

Receiver learns Channel Matrix H inverted Matrix H -1 used forrecalculation

of original input data streams 1..mm

ji j jii n sh y

1,

Signal at i th Rx antenna

YiSignal from j th Tx antenna

S j

n i: Noise at receiver

H =h 1,1h 2,1

h n,1

h 1,2h 2,2

h n,2

h 1,mh 2,m

h n,m

Transmit diversity for two antennas


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89


Benefit: Diversity gain, enhanced cell coverage

Each Tx antenna transmits the same stream of data with different coding and

different subcarriers -> Receiver gets replicas of the same signal which increasesthe SINR. Synchronization signals are transmitted only via the 1 st antenna eNode B sends different cell-specific reference signals per antenna It can be enabled on cell basis by O&M configuration

Processing is completed in 2 phases: Layer Mapping: distributing a stream of data into two streams Pre-coding: generation of signals for each antenna port

Spatial multiplexing (MIMO) for two antennas


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90


90

S1

S2

Benefit: Double the peak rate compared to a 1Tx antenna

Spatial multiplexing with two code words Supported physical channel: PDSCH

Two code words(S1+S2) are

transmitted inparallel to oneUE whichdoubles thepeak rate

LayerMapping

L1

L2

Precoding

Map ontoResourceElements

Map ontoResourceElements

OFDMA

OFDMA

Modulation

Modulation

Code word1

Code word2

Scale

W2

W1

2 code wordstransferred whenchannelconditions aregood

Signal generation is similar to TransmitDiversity: i.e. Layer Mapping & Precoding

Can be open loop or closed loop dependingif the UE provides feedback

DL adaptive open loop MIMO for two antennas


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91


91

Benefit: High peak rates (two code words) and good celledge performance (single code word)

2 TX antennas Dynamic selection between

Transmit diversity Open loop spatial multiplexing with

two code words Supported physical channel: PDSCH Dynamic switch considers the UE specific

link qualityTwo code words (A+B) aretransmitted in parallel to one UEwhich doubles the peak rate

One code word A istransmitted via twoantennas to one UEwhich improves the LiBu

AB

A

Downlink Adaptive Closed Loop MIMO


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92


92

2 TX antennas

Transmission mode 4 Dynamic selection for between

Rank 1 Rank 2

based on filtered CQI, PMI and rank

information Operator configurable thresholds for the

MIMO switch

same codewords

differentcodewords

Contents


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93


93

Day 1 LTE Overview





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94


94

Air Interface Protocols

Radio Protocols Architecture


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95


95

MAC

RLC

PDCP

Physical Layer

RRC

L1

L2

L3

Radio Bearer

Logical Channel

Transport Channels

Control Plane User Plane

Physical Channels

LTE Protocol Layers


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9696

RRC:

Broadcast of system information Radio connection management & Radio bearers Paging, handovers, QoS management, Radio Measurement Control

PDCP:

Ciphering, Header Compression (RoCH) Integrity protection for C-plane data Transfer of U-plane and RRC Data

LTE Protocol Layers


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9797

MAC:

Mapping & multiplexing of logical channels to transport channels Hybrid-ARQ error correction Priority handling, Scheduling Random access management Transport format selection (part of LA)

RLC: Transfer of upper-layer PDUs Managing different transfer modes Error correction (ARQ) Concatenation, Segmentation and reassembly of RLC SDUs

IP / TCP | UDP |

Application LayerNAS Protocol(s)(Attach/TA Update/)


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98

FDD | TDD - Layer 1( DL: OFDMA, UL: SC-FDMA )

Medium Access Control (MAC)

Physical Channels

Transport Channels

RLC(Radio Link

Control)

PDCP (Packet Data

ConvergenceProtocol)

RLC(Radio Link

Control)

PDCP (Packet Data


RLC(Radio Link

Control)

PDCP(Packet Data


RLC(Radio Link

Control)

PDCP(Packet Data


RLC(Radio Link

Control)

PDCP(Packet Data


Logical Channel

(E-)RRC(Radio Resource Control)

IP / TCP | UDP |

Radio Bearer

ROHC (RFC 3095)

Security

Segment./Reassembly

ARQ

Scheduling /Priority Handling

HARQ

De/Multiplexing

CRC

Coding/Rate Matching

Interleaving

Modulation

Resource Mapping/MIMO

NAS Protocols Transfer


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99


99

MME

eNBUE MME

NAS NAS

RRC RRC

PDCP PDCP

RLC RLC

MAC MAC

PHY PHY

Data Flow ExampleE-Mail (IP packet) FTP Download (IP packet)


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100


100

Header HeaderPayload Payload

PDCPHeader

PDCPHeader

PDCP PDU PDCP PDU

PDCP SDU PDCP SDU

RLCHeader

RLCHeader

RLCHeaderRLC SDU RLC SDU RLC SDU

MACHeader

MACHeader

RLC PDU RLC PDU

Transport block Transport blockCRC CRC

( p ) ( p )

H HPayload PayloadPDCP

RLC

MAC

PHY

PDU = Protocol Data UnitSDU = Service Data Unit


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101


101

LTE Channels

LTE Channels


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102


102

Upper Layers

RLC

MAC

PHY

Logicalchannels

Transportchannels

B C C H

C C C H

P C C H

MT

C H

M C C H

B C H

P C H

DL - S

C H

RA

C H

UL - S

C H

P B

C H

P D

S C H

P HI C H

P D

C C H

P C F I C H

P M

C H

P U C C H

P RA

C H

P U S C H

M C H

C C C H

D C C H

DT

C H

ULDL

Air interface

D C C H

DT

C H


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Downlink Physical Channels


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104


104

PDSCH: Carries user dataPBCH: For system info (cell IDs, cell status, allowed

services, RACH parameters)

PMCH: For multicast traffic as MBMS servicesPHICH: Carries H-ARQ Ack/Nack messages from eNB

to UE in response to UL transmission

There are no dedicated channels in LTE, neither in UL nor DL

PCFICH: Carries details of PDCCHs format (e.g.# of symbols)PDCCH: Carries resource assignment messages for downlink capacity allocations and scheduling

grants for uplink allocations

Downlink Physical Channels Allocation PBCH


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105

PBCH: Occupies the central 72 subcarriers across 4 symbols Transmitted during second slot of each 10 ms radio frame on

all antennas PCFICH: Can be transmitted during the first 3 symbols of

each TTI Occupies up to 16 RE per TTI

PHICH:

Normal CP: Tx during 1 st symbol of each TTI Extended CP: Tx during first 3 symbols of each TTI Each PHCIH group occupies 12 RE

PDCCH: Occupies the RE left from PCFICH and PHICH within the first 3

symbols of each TTI Minimum number of symbols are occupied. If PDCCH data is

small then it only occupies the 1 st symbol PDSCH:

Is allocated the RE not used by signals or other physicalchannels

Uplink Channels


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106


106

MAC layer provides the logical channels to RLC layer Transport channels in LTE have been reduced (also for DL direction) by using

in shared channel operation ( no dedicated channels like in WCDMA )

Uplink Physical Channelsh l l k h d h l


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107


107

PUSCH : Physical Uplink Shared Channel Intended for the user data (carries traffic for

multiple UEs)

PUCCH: Physical Uplink Control Channel Carries H-ARQ Ack/Nack indications, uplink

scheduling request, CQIs and MIMO feedback If control data is sent when traffic data is being

transmitted, UE multiplexes both streamstogether

If there is only control data to be sent the UEuses Resources Element at the edges of thechannel with higher power

PRACH: Physical Random Access Channel For Random Access attempts. PDCCH

indicates the Resource elements for PRACHuse PBCH contains a list of allowed preambles

(max. 64 per cell in Type 1 frame) and therequired length of the preamble

RACH

CCCH DCCH DTCH

UL-SCH

PRACH PUSCH PUCCH

Logical

Transport

PHYS.

RLC

MAC


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108


108

Physical Resource Mapping

DL Cell-Specific Reference Signals Mapping

Channel estimation in LTE is based on reference signals


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109


109

0l 0 R

0 R

0 R

0 R

6l 0l 0 R

0 R

0 R

0 R

6l

O n e a n

t e n n a p o r t

T w o a n

t e n n a p o r t s

Resource element ( k,l )

Not used for transmission on this antenna port

Reference symbols on this antenna port

0l 0 R

0 R

0 R

0 R

6l 0l 0 R

0 R

0 R

0 R

6l 0l

1 R

1 R

1 R

1 R

6l 0l

1 R

1 R

1 R

1 R

6l

0l 0 R

0 R

0 R

0 R

6l 0l 0 R

0 R

0 R

0 R

6l 0l

1 R

1 R

1 R

1 R

6l 0l

1 R

1 R

1 R

1 R

6l

F o u r a n

t e n n

a p o r t s

0l 6l 0l

2 R

6l 0l 6l 0l 6l 2 R

2 R

2 R

3 R

3 R

3 R

3 R

even-numbered slots odd-numbered slots

Antenna port 0


Antenna port 1


Antenna port 2


Antenna port 3

Cell-specific reference signals shall be transmitted in all downlink Slots Reference signals position in time domain is fixed whereas in frequency

domain it depends on the Cell ID and slot number parity In case more than one antenna is used (e.g. MIMO) the Resource

elements allocated to reference signals on one antenna are DTX on theother antennas

MIMO and the OFDMA Reference SymbolsANTENNA 1 ANTENNA 2f

UnusedResourceElement


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110


OFDM Symbols/ Time Domain

S u

b - c a r r

i e r s

/ F r e q u e n c y

D o m a i n

ANTENNA 1

OFDM Symbols/ Time Domain

S u

b - c a r r

i e r s

/ F r e q u e n c y

D o m a i n

ANTENNA 2 ReferenceSymbol

DL Physical Channels Allocation PBCH:


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111


111

PBCH: Occupies the central 72 subcarriers across 4 symbols Transmitted during second slot of each 10 ms frame

on all antennas PCFICH:

Transmitted during the first symbol of each TTI Occupies up to 16 RE per TTI

PHICH: Tx during 1 st symbol of each TTI or alternativ during

symbols 1 to 3 of each TTI PhichDur Each PHCIH group occupies 12 RE

PDCCH: Occupies the REs not used by PCFICH and PHICH

within the first 1, 2 or 3 symbols of each TTI (case 1.4MHz: within the first 2, 3 or 4 symbols)

In RL15TD: configuration static bymaxNrSymPdcch

PDSCH: Is allocated the RE not used by signals or other

physical channels

RB

Uplink Physical Signals and Channels


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112


112

Uplink Reference Signals Demodulation Signals:

Used for channel estimation in theeNodeB receiverLocated in the 4 th symbol of each slotand spans the same bandwidth as theallocated uplink data

Sounding Reference Signals:Provides uplink channel qualityestimation as basis for the ULscheduling decisions -> similar in use asthe CQI in DLSent in different parts of the bandwidthwhere no uplink data transmission isavailable.

Uplink Physical Channels Physical Uplink Shared Channel (PUSCH) Physical Uplink Control Channel (PUCCH) Physical Random Access Channel

(PRACH)


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Mobility and Connection States (1/2)


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114


114

2 sets of states for the UE are defined based on the information held in the MME : EMM: EPS Mobility Management States

ECM: EPS Connection Management States EMM:

EMM- DEREGISTEREDMME holds no valid location information about the UE (location unknown)

EMM- REGISTEREDUE performs Tracking Area Update procedures to notify availabilityUE responds to paging messagesUE performs service request procedure to establish the radio bearers whenuplink data is to be sent

EMMderegistered

EMMregistered

AttachDetach

EPS: EvolvedPacket System

Mobility and Connection States (2/2)


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115


115

ECM: UE and MME enter ECM-CONNECTED state when the signaling connection is

established between UE and MME UE and E-UTRAN enter RRC-CONNECTED state when the signaling

connection is established between UE and the E-UTRAN

ECM idle ECMconnected

S1 connection establishment

S1 connection release

RRC idle RRC

connected

RRC connectionestablishment

RRC connectionrelease

UEE-UTRAN MME

MMES1 connectionRRC connection

LTE Radio Resource Control (RRC) States

dl d


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116116

RRC Idle state No signalling connection between UE

and network exists

UE performs cell reselections Paging needed when the there is data in

downlink direction RACH procedure used on RRC

connection establishment No RRC context stored in the eNB (No

C-RNTI).

UEs RRC connection can be maintained even if UE is inactive RRC connection may be released due to the following reasons:

RRC Connected State A signalling connection exists between

UE and network

UE location is known in MME with anaccuracy of a cell ID

The mobility of UE is handled by thehandover procedure

The UE performs the tracking areaupdate procedure

inactive > x min1. UE is inactive for a long time

2. Max number of RRC connected UEs reached.Then, longest inactive UE is released

EMM & ECM States TransitionsPower On


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117


117

EMM_Deregistered

ECM_Idle

Power On

Registration (Attach)

EMM_Registered

ECM_Connected

Allocate C-RNTI, S_TMSI Allocate IP addresses Authentication Establish security context

Release RRC connection Release C-RNTI Configure DRX for paging

EMM_Registered

ECM_Idle

Release due toInactivity

Establish RRC Connection Allocate C-RNTI

New TrafficDeregistration (Detach)Change PLMN

Release C-RNTI, S-TMSI Release IP addresses

Timeout of Periodic TAUpdate

Release S-TMSI Release IP addresses


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118


LTE Bearers


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The Default Bearer Concept


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120


120

Each UE that is attached to the LTE network has at least one beareravailable, that is called the default bearer .

Its goal is to provide continuous IP connectivity towards the EPC ( always-on concept) From the QoS point of view, the default bearer is normally a quite basic

bearer If an specific service requires more stringent QoS attributes, then a

dedicated bearer should be established.

cell

S1-U

UE

S5PDN

Sgi

eNB

ServingGateway

PDNGateway

Default EPS Bearer

MME

S1-MMES11

EPS Bearer QoS Attributes


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121


EPS Bearer QoS Parameters(To be defined per Bearer )

Default Bearer/Dedicated Bearer

GBR/N-GBR

MBR

UL/DL-TFT

QCI

ARP

EPS Bearer QoS Parameters(To be defined per User) AMBR


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Contents

Day 1


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123


123




LTE/EPS Mobility Areas

T d fi d f h dli f bili i LTE/EPS


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124


124

Two areas are defined for handling of mobility in LTE/EPS:

Tracking Area (TA) It is the successor of location and routing areas from 2G/3G. When a UE is attached to the network, the MME will know the UEs

position on tracking area level. In case the UE has to be paged, this will be done in the full tracking

area. Tracking areas are identified by a Tracking Area Identity (TAI).

The Cell Smallest entity regarding mobility When the UE is connected to the network, the MME will know the

UEs position on cell level Cells are identified by the Cell Identification (CI) and by the Physical

Cell Identification (PCI)

Tracking Areas


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125


125

S-eNBTAI3TAI3

TAI3

TAI3

TAI3TAI3

TAI3

MME

eNB

TAI2

TAI2TAI2

TAI2

TAI2

TAI2TAI2

TAI2

TAI1

TAI1TAI1

TAI1

TAI1 eNB 1 2

MME

3

Cell Identity

Tracking Area

Tracking Area Identity (TAI) vs. Tracking Area Code (TAC)TAI= MCC + MNC + TAC

Tracking Area Update(TAU)Procedure triggered by theLTE-UE moving to a newTA.TAU are performed by theLTE-UE in both idle andconnected mode.(GSM/UMTS difference)For further info refer to TS23.401 chapter 5.3.3.0

LTE Handover Principles


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126


126

Lossless Packets are forwarded from the source to the target

Network-controlled Target cell is selected by the network, not by the UE Handover control in E-UTRAN (not in packet core)

UE-assisted Measurements are made and reported by the UE to the network

Late path switch Only once the handover is successful, the packet core is involved

Handover Procedure

Handover Late path


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127


127

S-GW + P-GW

MME

SourceeNB

TargeteNB

MME MME MME

= Data in radio= Signalling in radio= GTP tunnel= GTP signalling

= S1 signalling= X2 signalling

Before handover Handoverpreparation Radio handoverLate pathswitching

S-GW + P-GW

S-GW + P-GW S-GW + P-GW

X2

Intra frequency handover via X2


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128


128

Basic Mobility Feature Event triggered handover based

on DL measurements (ref.signals)

Network evaluated HO decision Operator configurable

thresholds for

coverage based and best cell based handover

Data forwarding via X2 Admission Control gives priority

to HO related access over otherscenarios

S1

S1 X2

MMES-GW

P-GW

Feature ID(s): LTE53

A reliable and lossless mobility

Intra LTE Handover via S1


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129


129

Extended mobility option

Handover in case of no X2 interface between eNode B,

e.g. multi-vendor scenarios

eNode Bs connected to different CN

elements, e.g. MME relocation Same measurements and triggers as for X2

based handover

DL Data forwarding via S1S1

S1MMESAE-GW

UE Identifications


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130


130

IMSI International Mobile Subscriber Identity

GUTI Global Unique Temporary Identity

C-RNTI Cell Radio Network Temporary Identity

S-TMSI S Temporary mobile subscriber IdentityRA-RNTI

Random Access Radio Network Temporary IdentitySI-RNTI

System Information Network Temporary IdentityP-RNTI

Paging Radio Network Temporary Identity

Contents

Day 1


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131


131

y LTE Overview LTE Architecture LTE Interfaces and Protocols LTE Air Interface



Radio Planning Process Overview

DIMENSIONING C t ti f b f it t


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132


132

DIMENSIONING: Computation of number of sites to servecertain area to fulfil customer requirements (Dim Tool)

NOMINAL PLANNING: Creation of a nominal Plan Coverage planning with planning tool (i.e. Atoll, NetAct

Planner)Based on coverage thresholds

Capacity analysis Site surveys and site pre-validation

DETAILED PLANNING: Capacity analysis with planning tool Site validation eNodeB Parameter planning (i.e. frequency, paging groups,

site data built with default parameters)

PRE-LAUNCH OPTIMISATION: Cluster acceptance Drive test measurements, analysis and changes

implementation Data build assessment/ consistency

DIMENSIONING

NominalPlanning

DetailedPlanning

Pre-launchOptimisation


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Link Budget Example


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134


134

DL ULOperating Band (MHz) 2300

Channel Bandwidth (MHz) 20Tx Power per Antenna (dBm) 40.0 23.0

Antenna Gain (dBi) 18.0 0.0Feeder Loss (dB) 2.0 -Body Loss (dB) - 1.0

Total Tx Power Increase (dB) 3.0 -User EIRP (dBm) 59.0 22.0Feeder Loss (dB) - 2.0

Antenna Gain (dBi) 0.0 18.0Noise Figure (dB) 8.0 3.0

Body Loss (dB) 1.0 -

Total Number of PRBs per TTI 100Cyclic Prefix Normal Normal

Number of OFDM Symbols per Subframe 14 14DL-to-UL configuration DL-to-UL Conf 2

Special Subframe Format "S" Subframe Format 7Number of Regural DL/UL Subframes 6.0 2.0

Number of Special Subframes 2.0DwPTS/UpPTS Length (OFDM symbols) 10.0 2.0

GP Length (OFDM symbols) 2.0

DL/UL Ratio 74.29% 20.00%

Modulation and Coding Scheme 5-QPSK 4-QPSKService Type Data

Cell Edge User Throughput (kbps 1024 512Number of PRBs per User 87 40

Channel ModelEnhanced Pedestrian A 5 Hz Antenna Configuration 4Tx-4Rx 1Tx-4Rx

Required SINR at Cell Edge (dB) -0.89 -5.29Maximum SINR at Cell Edge (dB) -0.03 -

Cell Load (%) 30% 30%Interference Margin [Formula/Simulation] (dB) 1.23 1.00

Number of Received Subcarriers (dB) 30.8 26.8Thermal Noise Density (dBm/Hz) -174

Subcarrier Bandwidth (kHz) 15Noise Power per Subcarrier (dBm) -132.17

Receiver Sensitivity (dBm) -94.27 -107.65

Maximum Allowable Path Loss (dB)(c lu t ter not considered)

154.05 144.65

Link Budget Example


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Clutter Type High Dense Urban Dense Urban Urban Suburban Rural (open)Maximum Allowable Path Loss (dB)

(clutter not considered) 144.65

BTS Antenna Height (m) 20.0 20.0 20.0 22.0 24.0MS Antenna Height (m) 1.0 1.0 1.0 1.0 1.0

Average Penetration Loss (dB) 27.0 24.0 20.0 18.0 12.0Standard Deviation Outdoor (dB) 10.0 10.0 8.0 8.0 8.0

Cell Area Probability 95.0% 95.0% 95.0% 95.0% 95.0%Log Normal Fading Margin (dB) 11.5 11.5 8.6 8.6 8.6Gain Against Shadowing (dB) 3.3 3.3 2.4 2.4 2.4

Maximum Allowable Path Loss (dB)(clut ter con sidered)

109.41 112.41 118.46 120.48 126.46

Cell Range (km) 0.142 0.166 0.277 0.383 0.655

Cell Radius Comparison


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0.000.501.001.502.002.503.003.504.00

2600 FDD-LTE 2300 TDD - LTE 1800 FDD-LTE 750 FDD-LTE

Dense Urban Urban Sub Urban Rural

Clutter 2600 FDD-LTE 2300 TDD - LTE 1800 FDD-LTE 750 FDD-LTE Dense Urban 0.14 0.16 0.23 0.62

Urban 0.22 0.25 0.37 1.00

Sub Urban 0.40 0.43 0.58 1.88

Rural 0.82 0.89 1.33 3.49

Peak data rates LTE FDDDirectly linked to available spectrum bandwidth


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1.4 3 5 10 15 20

Peak data rate

[Mbps]

Downlink

Uplink

Bandwidth [MHz]

150

125

100

75

50

258.8 / 2.8

22.2 / 7.0

36.7 / 11.4

73.7 / 22.9

110.1 / 35.2

149.8 / 46.9100Mbpsservicerequires

2x15MHzbandwid th

Peak data ratesDriven by LTE terminal capabilities


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Class 1 Class 2 Class 5Class 3 Class 4

Peak rate DL/UL

RF bandwidth

Modulation DL

Modulation UL

Rx diversity

MIMO DL

10/5Mbps

50/25Mbps

100/50Mbps

150/50Mbps

300/75Mbps

20 MHz* 20 MHz* 20 MHz* 20 MHz* 20 MHz*

64 QAM 64 QAM 64 QAM 64 QAM 64 QAM

16 QAM 16 QAM 16 QAM 16 QAM 64 QAM

yes yes yes yes yes

optional 2 x 2 2 x 2 2 x 2 4 x 4

All LTE deviceswhich have beensold today

All 3GPP Rel.8 LTE terminals can receive 20 MHz bandwidth, but (baseband) processingpower is variable

LTE Radio Planning toolsThe recommended Radio Planning tools provided by 3rd Party are:


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Atoll from FORSK NetAct MultiRadio Planner (NAP) from AIRCOM Planet from MENTUM

Input Data for planning an LTE network


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General (technology independent) inputsDigital maps

Areas to be servedSite data if not green field case along with site limitationsPropagation model data

LTE specific partPower budgetUE and BTS Equipment details (NF, Link Adaptation etc.)Grade of Service Expected (e.g. location probability and maximum outage as% of customers)

Number of customersServices usedTraffic profiles

PCI PlanningIntroduction


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There are 504 unique Physical Cell IDs (PCI)Physical Layer Cell Identity = (3 N ID1) + N ID2

NID1: Physical Layer Cell Identity group. Range 0 to 167 Defines SSS sequence

NID2: Identity within the group. Range 0 to 2 Defines PSS sequence

Resource elementallocation to theReference Signal

PCI impacts the allocation ofresource elements to thereference signal and the setof physical channels

Allocation pattern repeats every 6 th Physical Layer Cell Identity

PCI PlanningRecommendations

Id = 6Id = 0


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In priority order (All four should be fulfilled, ideally)1. Avoid assigning the same PCI to neighbour

cells2. Avoid assigning mod 3 PCI to neighbour

cells3. Avoid assigning mod 6 PCI to neighbour

cells

4. Avoid assigning mod 30 PCI to neighbourcells

PCI is also used to calculate the PCFICH offset A term of the calculation is: 'pyhCellId

modulo {2 * (number of PRBs in DL)}

PCI of neighbour cells should have differentPCI modulo {2 * (number of PRBs in DL)} toavoid the same frequency (location) of thePCFICH

Id = 5

Id = 4

Id = 3Id =11

Id =10

Id = 9

Id = 8

Id = 7

Id = 2

Id = 1

Example 1 PCI Identity Plan

Example 2 PCI Identity Plan

Trusted solutionby top telecom


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lte overview 110913 day1 v3

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