LTE Planning

MARKET

3GPP Time Line and Evolution 2006

2007

2009

2008

Common IMS

MMTel

R9 2010

R10 2011 LTE Adv

2005

LTE

2004

R8

EPC

2003

R7

HSPA +

2002

HSPA UL

2001

R6

R5

HSPA DL

UMTS

2000

R4

IMS

R99

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

•

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

•

Lower latency : –

as

for

the

downlink

to

uplink

from

HSDPA

Rel-

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 service machinery that can be used in the Services Connectivity Layer to provide services on top of the IP connectivity provided by the lower layers.  For example, to support the voice service, IMS can provide Voice over IP (VoIP) and interconnectivity to legacy circuit switched networks PSTN and ISDN through Media Gateways it controls.

EPC

( Evolved Universal Terrestrial Radio Access Network)

• Functionally the EPC is equivalent to the packet switched domain of the existing 3GPP networks. • EPC consist of : – MME ( Mobility Management Entity ) – SAE GW represents the combination of the two gateways, Serving Gateway (S-GW) and Packet Data Network Gateway (P-GW) – Home Subscriber Server (HSS) – Policy and Charging Rules Function (PCRF)

EPC Con’t  Mobility Management Entity (MME)

– MME is a controller at each node on the LTE access network. At UE in idle state (idle mode), MME is responsible for tracking and paging 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 do intra - LTE handover. – Used for bearer control, a different view R99 / 4 which is still controlled 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)

E-UTRAN (Evolved Universal Terrestrial Radio Access Network)

 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.

User Equipment  Functionally the UE is a platform for communication applications, which signal with the network for setting up, maintaining and removing the communication links the end user needs.  This includes mobility management functions such as handovers and reporting the terminals location, and in these 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 classical multicarrier modulation: (a) classical multicarrier system 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 singlecarrier 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

PILOT

Subcarrier Mapping

(Npilot -2)/2

Nsubcarrier data / 2

Nsubcarrier data / 2 BW

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

Npilot /2

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 Diversity Transmit 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-andwait retransmission system.

Adaptive Modulation

SNR-CQI Mapping for BLER 10%

Adaptive Modulation Illustration

Constellation Diagram QPSK

16 QAM 64 QAM

Adaptive Modulation and Coding

Standard for CQI mapping

Scheduling

Control Plane Control 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 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. Uplane 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 .

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

LTE Downlink Logical Channel Con’t • 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 several MTCHs. 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 control information, e.g. for controlling actions including power control, handover, etc..

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 also for traffic/other control channels.

• Broadcast Channel ( BCH ) > The LTE transport channel maps to Broadcast Control (BCCH)

> >

Fixed, pre-defined transport format Broadcast in the entire coverage area of the cell

Channel

LTE Downlink Transport Channel Con’t •

•

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 long cyclic 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 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 user information. 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 Slot GP : Guard Period UpPTS : Uplink Pilot Time Slot.

LTE TDD Sub Frame Allocations

D : sub frame for downlink transmission S :"special" sub frame used for a guard time U : sub frame for uplink transmission

Planning Coverage

MAPL Calculation Data Rate Transmitter - eNodeB a. Tx Power b. Tx Antenna Gain c. Loss System d. EIRP

Downlink Link Budget LTE Unit Value kbps 1000

Info

dBm dB dB dBm

46 18 3 61

a b c a+b+c

Receiver - UE e. Ue Noise Figure f. Thermal Noise g. SINR h. Receiver Sensitivity i. Interference Margin

dB dBm dB dBm dB

7 -102.7 -5 -100.7 3

e k*T*B g e+f+g i

j. Control Channel Overhead k. Rx antenna gain l. Body Loss

dB dBi dB

1 0 0

j k l

MAPL

dB

157.7

d-h-i-j+k-l

Propagation Model • LTE – 700 MHz – Okumura-Hatta Lp  69,55  26,16 log f – 13,82 log hB - CH  [44,9 – 6,55 log hB] log d

• LTE – 2100 MHz – Cost 231-Hatta Lp  46,3  33,9 (logfc )  13,82 loghT  a(hR )  (44,9  6,55loghT )logd  CM

• LTE – 2600 MHz – SUI Lp  109.78  47.9 log (d/100)

Pathloss SUI Lp = 109.78 + 47.9 log (d/100)

47.9 log( d / 100)  Lp 109.78 log( d / 100)  ( Lp 109.78) / 47.9 (d / 100)  10( Lp109.78) / 47.9 d  100 x10( Lp109.78) / 47.9 (157.7 109.78) / 47.9 d  100 x10 1.00042 d  100x10 d  1000.966 meters

Radius Calculation

L = 2,6 d2

L = 1,3 . 2,6 . d2

L = 1,95 . 2,6 . d2

Radius Calculation For Omni directional

For trisectoral

L = 2,6 d2

L = 1,95 . 2,6 . d2

L  2.6 x (1)2 L  2.6 km2

L  1.95 x 2.6 x (1) L  5.07 km2

2

Number of eNodeB • Urban Area (Trisector) – total area 242.928 km2 – NeNodeB  242.928 / 5.07 – N eNodeB  48

PLANNING CAPACITY

Calculation steps: 1. 2. 3. 4. 5. 6. 7.

Number of user User density Services and Type Penetration : building, vehicular, pedestrian BHCA and call duration OBQ Site calculation

Number of User Un = Uo (1 + gf)n

Uo is Uou or Uosub Where:

UoN = a x b x d x N • • • • • • • • •

Un Uo a b d N gf n u/sub

: num of user on year ‘n’ : initial num of user (based on urban/sub-urban) : percent of cellular user (%) : penetration of operator A (%) : Percent of LTE user : num of civilian in the object area : num of user growth factor : planned year : urban or sub-urban penetration (%)

Uou = u x UoN Uosub = sub x UoN

Customer Prediction Parameter Ex : • Population • Cellular penetration • LTE penetration • LTE provider A penetration

= 1445892 people = assumption 80% = assumption 10 % = assumption 50 %

Population

1445892

people

Customer cellular (80%)

1156713

user

Customer LTE (10%)

115671

user

Customer LTE provider A (50%)

57835

user

User prediction in 5th years • U5 = 57835 ( 1 + 0.05 )5 assumption fp=5% = 73814 user

Example User Calculation Ex : • • • •

urban penetration suburban penetration Urban user = 73814 x 60 % Suburban user = 73814 x 40 %

= assumption 60 % = assumption 40 % = 44288 user = 29525 user

User Density Lu = L x u

Lsub = L x sub

• Lu : urban area wide • Lsub : sub-urban area wide • L : object area wide

Cu = Un/ Lu

• Cu : Urban area density • Csub : sub-urban area density

Csub = Un/Lsub

Example User Density Calculation Ex : • urban area penetration • suburban area penetration • Openarea

= assumption 40 % = assumption 40 % = assumption 20 %

=> Urban area wide (Lu) Sub-urban area wide (Lsub)

: 242,928 km2 : 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 – Vehicular – Pedestrian

: 50 % : 30 % : 20 %

• Penetration (p) per type per service e.g: BUILDING VoIP usage penetration = 0.5 BUILDING FTP usage penetration = 0.4 PEDESTRIAN Video usage penetration = 0.3 • BHCA (B) per type per service e.g: BUILDING VoIP usage penetration = 0.008 BUILDING FTP usage penetration = 0.009 PEDESTRIAN Video usage penetration = 0.008 • Call duration (h) per type per service (ms) e.g: BUILDING VoIP usage penetration = 60 BUILDING FTP usage penetration = 50 PEDESTRIAN Video usage penetration = 50

Penetrasi User (p) Building Pedestrian Vehicular 0,5 0,5 0,2 0,3 0,3 0,2

Voip Video FTP type

0,4

0,4

call duration (h)

0,3

service

net user bit rate (Rb)

VoIP

64000

voip

video

ftp

building

60

40

50

pedestrian

60

50

70

FTP

1000000

vehicular

60

40

80

Video

384000

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

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

• Video OBQT = cT x Cu; T x pT x RbVid x BT x hT T : Type (Building; Vehicular; Pedestrian)

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

OBQ cont’d OBQ total = OBQVoIP + OBQFTP + OBQVideo

Where: OBQVoIP = OBQvehicular + OBQbuilding + OBQ pedestrian OBQFTP = OBQvehicular + OBQbuilding + OBQ pedestrian OBQVideo = OBQvehicular + OBQbuilding + OBQ pedestrian

OBQ cont’d 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

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

eNodeB Capacity N symbol per subframe bit PeakBitRat e[ Mbps]  xN subcarriers x Hz 1ms 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 (L) L

Site Calculation

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

km2

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

• Radius (d) d

= (L / 2.6 / 1.95) ^ 0.5

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

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 be seen in the LTE specification 3GPP.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 Band after determining the frequency band, set the transmitter frequency as the frequency and morpho class used

Setting Transmitter Frequency Band Con’t

Environtment Delete user

Delete environtment

Delete User Profile Delete service then setting service type

Services Delete 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 of Models and Tool, Coverage and Capacity Estimation of 3GPP Long Term Evolution radio interface. 2009. [2] Coverage and Capacity Dimensioning Recommendation: Ericsson. 2009. [3] Holma, Harri and Antti Toskala. WCDMA for UMTS – HSPA Evolution and LTE. John Willey and Son: 2007. [4] 3GGP. TS 36.XXX “LTE TS Group Series”. 2009.