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3GPP Time Line and Evolution

LTE Requirement (3GPP TR 25.913)

• Peak data rate 100 Mbps (DL) and 50 Mbps (UL) to 20 MHz

• Throughput increased by 3-4 times and 2-3 times for the downlink to uplink from HSDPA Rel 6 ( DL =

14.4 Mbps , to use transmitter sites that have been used in UTRA / GERAN

• Throughput increased by 3-4 times and 2-3 time UL = 5.7 Mbps )

• Spectrum efficiency by continuing as for the downlink to uplink from HSDPA Rel-

6 (DL = 14.4 Mbps, UL = 5.7 Mbps)

• Flexible use of spectrum (1.4, 3, 5, 10, 15, 20 MHz)

• Lower latency :

– Radio access network latency ( user plane UE – RNC- UE ) below 10 ms

• The ability of the use mobility up to 350 km / hour

• Coverage up to a radius of approximately 5 km

• Enhance MBMS ( Multimedia Broadcast / Multicast Service ) efficiency ( 1 bit/s/Hz)

• Retaining 3GPP RAT ( Radio Access Technology ) which already exist and support internetworking with

him.

• Architecture simplification , minimization and packet – based interface , full IP

LTE Architecture

In the LTE network is divided into

2 basic network, namely:

1. E UTRAN (Evolved Universal

Terrestrial Radio Access Network)

2. EPC (Evolved Packet Core)

SERVICE

The IP Multimedia Sub-System (IMS) is a good example of servicemachinery that can be used in the Services Connectivity Layer toprovide services on top of the IP connectivity provided by the lowerlayers.

For example, to support the voice service, IMS can provide Voice overIP (VoIP) and interconnectivity to legacy circuit switched networksPSTN and ISDN through Media Gateways it controls.

EPC

• Functionally the EPC is equivalent to the packet switched domain of theexisting 3GPP networks.

• EPC consist of :

– MME ( Mobility Management Entity )

– SAE GW represents the combination of the two gateways, ServingGateway (S-GW) and Packet Data Network Gateway (P-GW)

– Home Subscriber Server (HSS)

– Policy and Charging Rules Function (PCRF)

( Evolved Universal Terrestrial Radio Access Network)

Mobility Management Entity (MME)

– MME is a controller at each node on the LTE access network. At UEin idle state (idle mode), MME is responsible for tracking andpaging procedure which includes retransmission therein.

– MME is responsible for selecting SGW (Serving SAE Gateway)which will be used during initial attach EU and the EU time to dointra - LTE handover.

– Used for bearer control, a different view R99 / 4 which is stillcontrolled by the gateway

Policy and Charging Rules Function (PCRF)In order to handle QoS as well as control rating and charging, and billing

EPC Con’t

Home Subscriber Server (HSS)For management and security subscriber, combination AUC and HLR

Serving SAE Gateway (SGW)

- Set the path and forwards the data in the form of packets of each user- As an anchor / liaison between the UE and the eNB at the time of the inter handover

- As a liaison link between the 3GPP LTE technology with the technology(in this case the 2G and 3G)

Gateway Packet Data Network (PDN GW)

- Provides for the UE 's relationship to the network packet- Provide a link relationship between LTE technology with technology non 3GPP (WiMAX) and 3GPP2 (CDMA 20001X and EVDO)

EPC Con’t

E-UTRAN

Role of Radio Access Network (RAN), namely Node B and RNC is

replaced with ENB, so as to reduce operational and maintenance cost

of the device other than the simpler network architecture

E-nodeB functions : all radio protocols, mobility management, header

compression and all packet retransmissions

As a network, E-UTRAN is simply a mesh of eNodeBs connected to

neighboring eNodeBs with the X2 interface.

(Evolved Universal Terrestrial Radio Access Network)

User Equipment

Functionally the UE is a platform for communicationapplications, which signal with the network for settingup, maintaining and removing the communication linksthe end user needs.

This includes mobility management functions such ashandovers and reporting the terminals location, and inthese the UE performs as instructed by the network

FREQUENCY & BANDWIDTH IN LTE

Key Consideration to Spectrum Selection

* Band Selection Source: 3GPP TS 36.101

Illustration for Spectrum Selection

Channel Bandwidth Flexibility

LTE provides channel bandwidth flexibility for operation in differently-sized

LTE supports paired and unpaired spectrum on the same hardware spectrum

Channel Bandwidth Impact

OFDM

OFDM vs Single Carrier

Spectral efficiency of OFDM compared to classicalmulticarrier modulation: (a) classical multicarriersystem spectrum; (b) OFDM system spectrum.

Motivation for OFDM Approaches• Advantages

– Efficient in the use of frequencies

– Highly scalable

– Overcome delay spread, multipath & frequency selective fading, and ISI

• Weaknesses– Frequency Offset

– Nonlinear Distortion (PAPR)

PAPR illustration

OFDM Concept

• Multicarrier modulation/multiplexing technique• Available bandwidth is divided into several sub-channels• Data is serial-to-parallel converted• Symbols are transmitted on different sub-channels

OFDM Block Diagram (Tx)

Diagram Block Contents:

• S/P Serial to Parallel Converter

• Sub-Carrier Modulator

• IFFT Inverse Fast Fourier Transform

• P/S Parallel to Serial Converter

• DAC Digital to Analog Converter

OFDM Block Diagram (Rx)

Diagram Block Contents:

• S/P Serial to Parallel Converter

• Sub-Carrier Modulator

• IFFT Inverse Fast Fourier Transform

• P/S Parallel to Serial Converter

• DAC Digital to Analog Converter

Cyclic Prefix• Useful for multipath delay spread• Guard Interval (cyclic prefix) : short & long

Type of Cyclic Prefix

OFDMA & SC-FDMA

OFDMA vs. SCFDMA Definition

OFDMA is a multiple access technique based on OFDM as the modulation technique. It is used for DL transmission in LTE

SC-FDMA is a hybrid UL transmission scheme in LTE which has single-carrier transmission systems with the long symbol time and flexible frequency allocation of OFDM.

SC-FDMA Diagram Block

SC-FDMA frequency-domain transmit processing (DFT-S-OFDM) showing localized and distributed subcarrier mappings.

Type of OFDMA Sub-Carrier

Data sub-carrier

– Carry QPSK, 16 QAM, 64 QAM symbol

Pilot sub-carrier

– It is used to facilitate channel estimation and coherent demodulation at the receiver

Null sub-carrier

– Guard sub-carrier

– DC sub-carrier

Subcarrier Mapping

(Npilot -2)/2 Nsubcarrier data / 2

PIL

OT

Nsubcarrier data / 2 Npilot /2

BW

Nsubcarrier data See slide #19 or 3GPP TS 36.104Npilot NFFT-Point - Nsubcarrier data

MULTI ANTENNA TECHNIQUE

Multiple Antenna Technique

Existing Tech Smart Antenna MIMO Antenna

Multiple Antenna Technique Two popular techniques in MIMO wireless systems:

Spatial Diversity: Increased SNR• Receive and transmit diversity

mitigates fading and improves link quality

Spatial Multiplexing: Increased rate• Spatial multiplexing yields

substantial increase spectral efficiency

Spatial DiversityTransmit Diversity

• Space-time Code (STC): Redundant data sent over time and space domains (antennas).

• Receive SNR increase about linearity with diversity order NrNt

• Provide diversity gain to combat fading

• Optional in 802.16d (2x2 Alamouti STBC), used in 3G CDMA

Spatial Multiplexing

MIMO Multiplexing

• Data is not redundant – less diversity but less repetition

• Provides multiplexing gain to increase data-rate

• Low (No) diversity compared with STC

LTE SUPPORTING TECHNOLOGIES

HARQ

AMC

HARQ

HARQ or retransmission scheme in LTE use stop-and-wait retransmission system.

Adaptive Modulation

SNR-CQI Mapping for BLER 10%

Adaptive Modulation Illustration

Constellation DiagramQPSK

16 QAM

64 QAM

Adaptive Modulation and Coding

Standard for CQI mapping

Scheduling

Control PlaneControl Plane (C-Plane) is use to describe the protocols that convey information from the DTE to the end user (the control) of a node, or between nodes in the network to conveying required information to set, control and clearing the connection protocol.

User plane (U-plane) is a protocol used directly in the transfer of user data from the DTE (Data Terminal Equipment) to the other end-users. U-plane provides the function of delivery or transfer user information, and include all relevant mechanisms of information transfer such as flow control and error recovery. In the user plane used approach layer .

User Plane

CONTROL PLANE

USER PLANE

LTE CHANNELS

LTE Layer Mapping

Layer Function• Radio Link Control Layer (RLC)

> Retransmission

> Segmentation

• Medium Access Control Layer (MAC)

> Uplink and downlink scheduling at the eNodeB

> HARQ

• Physical Layer (PHY)

> Modulation/demodulation

> Coding/decoding

LTE Downlink Channel Mapping

LTE Downlink Logical Channels

• Paging Control Channel ( PCCH)> A downlink channel that transfers paging information and system

information change notifications.> This channel is used for paging when the network does not know

the location cell of the UE

• Broadcast Control Channel (BCCH)> Provides system information to all mobile terminals connected to

the eNodeB.> A downlink channel for broadcasting system control information

• Common Control Channel (CCCH)

> Channel for transmitting control information between UEs andnetwork.

> This channel is used for UEs having no RRC connection with thenetwork.

• Multicast Control Channel (MCCH)> A point-to-multipoint downlink channel used for transmitting MBMS

> Control information from the network to the UE, for one or severalMTCHs.

> This channel is only used by UEs that receive MBMS

• Dedicated Control Channel (DCCH)> A point-to-point bi-directional channel that transmits dedicated

control information between a UE and the network.

> Used by UEs having an RRC connection

> This control channel is used for carrying user-specific controlinformation, e.g. for controlling actions including power control,handover, etc..

LTE Downlink Logical Channel Con’t

LTE Downlink Logical Channel Con’t

• Multicast Traffic Channel (MTCH)

> A point-to-multipoint downlink channel for transmitting traffic data

from the network to the UE.

> This channel is only used by UEs that receive MBMS

• Dedicated Traffic Channel (DTCH )

> A point-to-point channel, dedicated to one UE, for the transfer of

user information.

> A DTCH can exist in both uplink and downlink

LTE Downlink Transport Channel

• Paging Channel ( PCH)> Supports UE discontinuous reception (DRX) to enable UE power

saving

> Broadcasts in the entire coverage area of the cell;

> Mapped to physical resources which can be used dynamically alsofor traffic/other control channels.

• Broadcast Channel ( BCH )

> The LTE transport channel maps to Broadcast Control Channel

(BCCH)

> Fixed, pre-defined transport format

> Broadcast in the entire coverage area of the cell

• Multicast Channel ( MCH)

> Broadcasts in the entire coverage area of the cell;

> Supports MBSFN combining of MBMS transmission on multiple cells;

> Supports semi-static resource allocation e.g. with a time frame of a longcyclic prefix

• Downlink Shared Channel ( DL-SCH )

> Main channel for downlink data transfer. It is used by many logical channels.

> Supports Hybrid ARQ

> Supports dynamic link adaptation by varying the modulation, coding and transmit power

> Optionally supports broadcast in the entire cell;

> Optionally supports beam forming

> Supports both dynamic and semi-static resource allocation

> Supports UE discontinuous reception (DRX) to enable UE power saving

> Supports MBMS transmission

LTE Downlink Transport Channel Con’t

LTE Downlink Physical Channel

• Physical Downlink Shared Channel ( PDSCH)

> This channel is used for unicast and paging functions

> Carries the DL-SCH and PCH

> QPSK, 16-QAM, and 64-QAM Modulation

• Physical Downlink Control Channel ( PCSCH)> Informs the UE about the resource allocation of PCH and DL-SCH,

and Hybrid ARQ information related to DL-SCH

> Carries the uplink scheduling grant

> QPSK Modulation

Uplink Physical Channels

• Physical HARQ Indicator Channel (PHICH)

> Used to report the Hybrid ARQ status

> Carries Hybrid ARQ ACK/NAKs in response to uplink transmissions.

> QPSK Modulation

• Physical Braodcast Channel (PBCH)

> This physical channel carries system information for UEs

requiring to access the network.

> QPSK Modulation

LTE Uplink Channels

Uplink Physical Channels

• Physical Radio Access Channel ( PRACH)> for random access functions

• Physical Uplink Shared Channel ( PUSCH)> Carries the UL-SCH> QPSK, 16-QAM, and 64-QAM Modulation

• Packet Uplink Control Channel ( PUCCH)

> Sends Hybrid ARQ ACK/NAKs

> Carries Scheduling Request (SR)> Carries CQI reports> BPSK and QPSK Modulation

Uplink Transport Channels

• Random Access Channel (RACH)

> Channel carries minimal information

> Transmissions on the channel may be loss due to collisons

• Uplink Shared Channel ( UL–SCH )

> Optional support for beam forming

> Support HARQ

Uplink Logical Channels

• Common Control Channel ( CCCH)> Channel for transmitting control information between Ue and

network.> This channel is used for UEs having no RRC connection with the

network.

• Dedicated Control Channel ( DCCH)> A point-to-point bi-directional channel that transmits dedicated control

information between a UE and the network.> Used by UEs having an RRC connection.

• Dedicated Traffic Channel ( DTCH)

> A point-to-point channel, dedicated to one UE, for the transfer of userinformation.

> A DTCH can exist in both uplink and downlink.

LTE FRAME STRUCTUR> Functions

System can maintain synchronization and manage the different type of information that need to be carried between the eNodeB and UE

> LTE frame structure consist of 1. FDD ( Frequency division duplex)2. TDD ( Time division duplex )

> A radio frame has duration of 10 ms> A resource block spans 12 subcarriers over a slot duration of 0.5 ms> BW RB = 180 KHz> BW Subcarrier = 15 kHz

FDD Frame structure

TDD Frame Structure

DwPTS : Downlink Pilot Time SlotGP : Guard PeriodUpPTS : Uplink Pilot Time Slot.

LTE TDD Sub Frame Allocations

D : sub frame for downlink transmissionS :"special" sub frame used for a guard timeU : sub frame for uplink transmission

Planning Coverage

Downlink Link Budget LTE Unit Value Info

Data Rate kbps 1000

Transmitter - eNodeBa. Tx Power dBm 46 a

b. Tx Antenna Gain dB 18 b

c. Loss System dB 3 cd. EIRP dBm 61 a+b+c

Receiver - UE

e. Ue Noise Figure dB 7 ef. Thermal Noise dBm -102.7 k*T*B

g. SINR dB -5 g

h. Receiver Sensitivity dBm -100.7 e+f+gi. Interference Margin dB 3 i

j. Control Channel Overhead dB 1 j

k. Rx antenna gain dBi 0 kl. Body Loss dB 0 l

MAPL dB 157.7 d-h-i-j+k-l

MAPL Calculation

Propagation Model• LTE – 700 MHz

– Okumura-Hatta

• LTE – 2100 MHz

– Cost 231-Hatta

• LTE – 2600 MHz

– SUI

MTRTcp C)logd6,55logh(44,9)a(hlogh13,82)(logf33,946,3L

(d/100) log 47.9 109.78 Lp

d log hB] log 6,55– [44,9 CH - hB log 13,82– f log 26,16 69,55 Lp

Pathloss SUI

Lp = 109.78 + 47.9 log (d/100)

78.109)100/log(9.47 Lpd

9.47/)78.109()100/log( Lpd9.47/)78.109(10)100/( Lpd

9.47/)78.109(10100 Lpxd9.47/)78.1097.157(10100 xd

00042.110100xd

966.1000d meters

Radius Calculation

L = 2,6 d2

L = 1,95 . 2,6 . d2

L = 1,3 . 2,6 . d2

Radius Calculation

L = 2,6 d2L = 1,95 . 2,6 . d2

2(1) x 2.6 L

2.6 L

2(1) x 2.6 x 1.95 L

5.07 L 2km 2km

For Omni directional For trisectoral

Number of eNodeB

• Urban Area (Trisector)

– total area 242.928

–

–

2km

07.5/928.242eNodeBN

48eNodeBN

PLANNING CAPACITY

Calculation steps:

1. Number of user

2. User density

3. Services and Type

4. Penetration : building, vehicular, pedestrian

5. BHCA and call duration

6. OBQ

7. Site calculation

Number of User

Where:

• Un : num of user on year ‘n’• Uo : initial num of user (based on urban/sub-urban)• a : percent of cellular user (%)• b : penetration of operator A (%)• d : Percent of LTE user • N : num of civilian in the object area• gf : num of user growth factor• n : planned year• u/sub : urban or sub-urban penetration (%)

Uo is Uou or UosubUosub = sub x UoN

Uou = u x UoN

Un = Uo (1 + gf)n

UoN = a x b x d x N

Customer Prediction ParameterEx :

• Population = 1445892 people

• Cellular penetration = assumption 80%

• LTE penetration = assumption 10 %

• LTE provider A penetration = assumption 50 %

User prediction in 5th years

• U5 = 57835 ( 1 + 0.05 )5 assumption fp=5%

= 73814 user

Population 1445892 people

Customer cellular (80%) 1156713 user

Customer LTE (10%) 115671 user

Customer LTE provider A (50%) 57835 user

Example User Calculation

Ex :• urban penetration = assumption 60 %

• suburban penetration = assumption 40 %

• Urban user = 73814 x 60 % = 44288 user

• Suburban user = 73814 x 40 % = 29525 user

User Density

• Lu : urban area wide

• Lsub : sub-urban area wide

• L : object area wide

• Cu : Urban area density

• Csub : sub-urban area density

Lu = L x u Lsub = L x sub

Cu = Un/ Lu Csub = Un/Lsub

Example User Density Calculation

Ex :• urban area penetration = assumption 40 %

• suburban area penetration = assumption 40 %

• Openarea = assumption 20 %=>

Urban area wide (Lu) : 242,928 km2

Sub-urban area wide (Lsub) : 242,928 km2

=>Cu = 44288 / 242,928 = 182,31232 user/km2

Csub = 29525 / 242,928 = 121,54155 user/km2

Services and Type

• Services (Rb)– VoIP : 64 kbps

– FTP : 1000 kbps

– Video : 384 kbps

• Type (c)– Building : 50 %

– Vehicular : 30 %

– Pedestrian : 20 %

• Penetration (p) per type per servicee.g: BUILDING VoIP usage penetration = 0.5

BUILDING FTP usage penetration = 0.4PEDESTRIAN Video usage penetration = 0.3

• BHCA (B) per type per servicee.g: BUILDING VoIP usage penetration = 0.008

BUILDING FTP usage penetration = 0.009PEDESTRIAN Video usage penetration = 0.008

• Call duration (h) per type per service (ms)e.g: BUILDING VoIP usage penetration = 60

BUILDING FTP usage penetration = 50PEDESTRIAN Video usage penetration = 50

service net user bit rate (Rb)

VoIP 64000

FTP 1000000

Video 384000

typecall duration (h)

voip video ftp

building 60 40 50

pedestrian 60 50 70

vehicular 60 40 80

BHCA (B)

Service Building Pedestrian Vehicular

Voip 0,008 0,008 0,009

Video 0,007 0,008 0,009

FTP 0,009 0,008 0,008

Penetrasi User (p)

Building Pedestrian Vehicular

Voip 0,5 0,5 0,2

Video 0,3 0,3 0,2

FTP 0,4 0,4 0,3

OBQ (Offered Bit Quantity)• VoIP

OBQT = cT x Cu; T x pT x RbVoIP x BT x hT

• FTP OBQT = cT x Cu; T x pT x RbFTP x BT x hT

• VideoOBQT = cT x Cu; T x pT x RbVid x BT x hT

Note: if T= pedestrian, then “OBQT “ is pedestrian OBQ, “BT “ is pedestrian BHCA, etc.

T : Type (Building; Vehicular; Pedestrian)

OBQ cont’d

Where:

OBQVoIP = OBQvehicular + OBQbuilding + OBQ pedestrian

OBQFTP = OBQvehicular + OBQbuilding + OBQ pedestrian

OBQVideo = OBQvehicular + OBQbuilding + OBQ pedestrian

OBQ total = OBQVoIP + OBQFTP + OBQVideo

OBQtotal= 20,74860049 + 13,97825 + 8,260936 = 42,98779

OBQ

Service Building Pedestrian Vehicular

Voip 1,400158616 0,5600634 0,252029

Video 2,940333094 5,2505948 1,008114

FTP 16,40810878 8,1675919 7,000793

∑ 20,74860049 13,97825 8,260936

OBQ cont’d

eNodeB Capacity

ms

NxxN

Hz

bitMbpsePeakBitRat

subframepersymbol

ssubcarrier1

][

Bandwidth (MHz)Modulation

QPSK 16 QAM 64 QAM

1.4 2.016 Mbps 4.032 Mbps 6.048 Mbps

3 5.04 Mbps 10.08 Mbps 15.12 Mbps

5 8.4 Mbps 16.8 Mbps 25.2 Mbps

10 16.8 Mbps 33.6 Mbps 50.4 Mbps

15 25.2 Mbps 50.4 Mbps 75.6 Mbps

20 33.6 Mbps 67.2 Mbps 100.8 Mbps

Site Calculation• Site (L)

L = (50.4 x 3) / OBQtotal

= (50.4 x 3) / 42,98779 = 3,5172778 km2

• Radius (d)

d = (L / 2.6 / 1.95) ^ 0.5

= (3,5172778 / 2.6 / 1.95) ^ 0.5 = 0,832912489 km

50.4 Mbps ---> (asumption: using 64 QAM 1/1, BW = 10 MHz)

Site Calculation Con’t

• Number of eNodeB (M)

M = Lu / L

= 242,928 km2 / 3,5172778 km2

= 69,06704366

We use “Lu” JUST IN CASE we count urban capacity only

LTE Simulation Using Atoll

Getting Started with Atoll

New -> From a

Document

Template

Choose LTE

workspace

Setting Project Area

It is used to display the project area from the map raster.

To set the coordinate type and the area displayed on the worksheet.

Import Raster Map

raster is a contour map based on the topography of the area. Raster consist of clutter map, height map and vector map

Import Raster Map Con’t

Clutter index -> Clutter Classes

Height index ->Altitude

Vector index ->Vectors

Frequency Band

frequency bands and can beseen in the LTE specification3GPP.org

Antenna Polarization Model

add the appropriate antenna used

Antenna Polarization Model

Setting Feeder

To setting feeder & connector loss at eNode B equipment

Setting Transmitter Frequency Bandafter determining the frequency band, set the transmitter frequency as the frequency and morpho class used

Setting Transmitter Frequency Band Con’t

EnvirontmentDelete user

Delete environtment

Delete User ProfileDelete service thensetting service type

ServicesDelete service then setting service type Edit Service

Service

VoIP Video FTP

Add User Profile

Assumption throughput user = 50 kbps

Add User Profile

Pedestrian

Vehicular

Add Environtment

Plotting eNode B

eNode B can be in place based on planning calculation or the use of existing nodeB or BTS

Make a Prediction

make predictions based on measured

fill of the receiver sensitivity specification

Click calculate

Coverage by Signal Level

Result Histogram and CDF Chart

Reference

[1] Abdul Basit, Syed. Dimensioning of LTE Network Description ofModels and Tool, Coverage and Capacity Estimation of 3GPPLong Term Evolution radio interface. 2009.

[2] Coverage and Capacity Dimensioning Recommendation:Ericsson. 2009.

[3] Holma, Harri and Antti Toskala. WCDMA for UMTS – HSPAEvolution and LTE. John Willey and Son: 2007.

[4] 3GGP. TS 36.XXX “LTE TS Group Series”. 2009.