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TELECOM ITALIA GROUP

| Alessandro Vaillant | TILAB – Wireless Access Innovation

Telecom Italia strictly confidential and proprietary

3GPP Long Term Evolution(LTE)

2

| Alessandro VaillantTELECOM ITALIA GROUP


LTE workshopStandardization aspects and active fora

System overview

Key enabling technologies for Long Term Evolution

LTE-SAE Architecture

LTE numerology

LTE numerology, peak data rates, UE categories

LTE DL and UL physical layer

OFDM, SC-FDMA, frame structure, PRB, channels

MIMO in LTE

MIMO techniques for LTE

QoS in LTE

QoS model in E-UTRAN, QCI and QoS attributes

Deployment strategy for EPS introduction

Trials results:

LSTI: LTE / SAE Trial Initiative

TI’s trials

LTE trial with Huawei

LTE advanced

Beyond LTE: standardization process

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Acknowledgements

The colleagues Andrea Barbaresi, Giuseppe Catalano, Valeria D’Amico, Gian Michele

Dell'Aera, Roberto Fantini, Maurizio Fodrini, Daniele Franceschini, Bruno Melis, are gratefully

acknowledged for the support provided in realizing this presentation

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Standardization aspects and active fora

5



LTE (Long Term Evolution): it is the evolution of the 3G radio access network. In standard, it is named Evolved-UTRAN (E-UTRAN)

SAE (System Architecture Evolution): it is the evolution of the 3G system architecture. It consist of a new core network full-IP named in standard Evolved Packet Core (EPC)

On the whole, the system is named Evolved Packet System (EPS = E-UTRAN + EPC)

Terminology

6



3GPP Organization

7



Release '99 (March 2000) : UMTS/W-CDMA

Release 5 (March 2002) : HSDPA, IMS

Release 6 (March 2005) : HSUPA, MBMS, IMS, Advanced receivers

Release 7 (June 2007) : HSPA+

Release 8 (Dec 2008) : HSPA+ enh, DC-HSDPA, CSoHSPA

• 3GPP work on 3G evolution started in November 2004

• Release 8 was frozen in March 2009 (even if latest spec in Sept 2009)

• Currently, LTE standardization work is in progress under Release 9

• Freeze of R9 specifications expected by March 2010

• Field trials held in 2009 (LSTI)

• Target Deployment in 2011

Long Term Evolution (LTE)

3GPP Evolution

LTE-Advanced in 3GPP R10 (2010)

8



Requirements of LTE (R8): “initial” targets [TR 25.913]

9



Requirements of LTE: R8 and beyond

Data plane : <10 ms (round trip delay)

Control plane : 50 ms (idle to active state)

Data plane : 10 ms (round trip delay)

Control plane : 100 ms (idle to active state)Latency

Up to 100 MHz Up to 100 MHz Up to 20 MHzUp to 20 MHzBandwidth

1.2 (1x2 SIMO)

2.0 (2x4 MIMO)

2.4 (2x2 MIMO)

2.6 (4x2 MIMO)

3.7 (4x4 MIMO)0.74 (1x2 SIMO)

1.69 (2x2 MIMO)

1.87 (4x2 MIMO)

2.67 (4x4 MIMO)

Average Spectrum efficiency

[bit/s/Hz/cell]

15 bit/s/Hz30 bit/s/Hz≈ 4.3 bit/s/Hz (1x2 SIMO)

≈ 8.6 bit/s/Hz (Virtual MIMO)≈ 16.3 bit/s/Hz

Peak Spectrum efficiency

500 Mbps (4x4 MIMO, low mobility)

1 Gbps (8x8 MIMO, low mobility)

86.4 Mbps (1x2 SIMO)

172 Mbps (Virtual MIMO)

326.4 Mbps (4x4 MIMO)

172.8 Mbps (2x2 MIMO) Peak data rate

UplinkUplink DownlinkDownlink

Next Releases LTE-A (3GPP targets in TR 36.913) Release 8 LTE performance

10



NGMN collaborates with several standardization body (like 3GPP, WiMAXForum, 3GPP2, IEEE) and try to address their activities so that the different standards follow the requirements shared among NGMN operators

In the NGMN alliance, TI is involved in the following groups:The Operating Committee, that coordinates all the NGMN activities;

The Steering Committee, that coordinates several technical project

The IPR group, where the guideline for the IPR treatment has been shared.

The Spectrum group.

The Trial group, that ensure the collaboration between NGMN and the trial initiatives: LTE/SAE Trial Initiative (LSTI) and WiMax Trial Initiative.

NGMN: Next Generation Mobile network

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System overview

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Key enabling technologies for Long Term EvolutionThis section presents the technical solutions for the evolved radio access and radio access network. These are the ingredients of the Long Term Evolution recipe!

x1

x2

x3

y1

y2

y3

MIMOMIMO Network EvolutionNetwork Evolution

eNB eNB

eNB

MME/UPE MME/UPE

S1

X2

X2

X2

Evolved Packet Core

E-UTRAN

OFDMOFDMScalable BandwidthScalable Bandwidth

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Scalable BandwidthThe UMTS spectrum allocation did not allow a larger carrier bandwidth than 5

MHz: using equaliser receivers WCDMA/HSPA provides attractive performance at 5 MHz, and at the same time the receiver complexity remains reasonably low.

Higher bit rates can generally be obtained by using larger bandwidth, as a consequence LTE allows larger bandwidth than UMTS, reaching up to 20 MHZ.

At the same time smaller bandwidth were needed to allow simpler spectrumrefarming.

1.4 MHz

3.0 MHz

5.0 MHz

10 MHz

20 MHz High Data Rates

LTE was defined with a scalable bandwidth: 1.4 MHz, 3.0 MHz, 5 MHz, 10 MHz and 20 MHz are possible.

W-CDMA is not suitable to support flexible bandwith, moreover the equalization for large bandwidth may be too complex.

OFDMAOFDMA

Scalable BandwidthScalable Bandwidth

14



Orthogonal Frequency Division Multiplexing (OFDM) is a particular form of multi-carrier modulation (MCM).

MCM is a parallel transmission method which divides a high bandwidth signal into several narrower bandwidth subcarriers and transmits data simultaneously on each subcarrier.

Orthogonal Frequency Division Multiplexing

…

Sub-carriersFFT

Time

Symbols

5 MHz Bandwidth

Guard Intervals

…Frequency

OFDMOFDM

15



In OFDM the frequencies of the individual sub-carriers are chosen in a way that they do not interfere with each other since they are orthogonal. The demodulator of one subcarrier does not “see” the modulation of the others, so there is no cross talk between subcarrier even if their spectra overlap.

This allow to “pack” the subcarriers more densely than with traditional FDM thus increasing the spectrum efficiency.

Orthogonal Frequency Division MultiplexingOFDMOFDM

16



Fortunately, the apparently very complex processes of modulating (and demodulating) thousands of subcarriers simultaneously are equivalent to DFT operations for which efficient FFT algorithms exist.

Orthogonal Frequency Division Multiplexing

OFDM is well suited for high data rate systems which operate in multi-path environments because of its robustness to delay spread. The introduction of a guard interval enables an OFDM system to operate in multi-path channels without the need for a complex equalizer. A Cyclic Prefix is created simply by selecting the last part of an OFDM symbol, make a copy of it and place the copy in front of the symbol (hence the term “prefix”)

| α0 | | α1 | | α2 |

Δ1 Δ2

α0

α1

α2

| α0 | | α1 | | α2 |

Δ1 Δ2

| α0 | | α1 | | α2 |

Δ1 Δ2

α0

α1

α2

α0

α1

α2

OFDMOFDM

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Multi-Antenna techniques

x1

x2

x3

y1

y2

y3

Multiple input multiple output (MIMO) antenna technologies are required to achieve the higher LTE bit-rate targets.

MIMO is simpler to implement with OFDMA than with CDMA, and it is more effective, since OFDMA is more robust to multipath and MIMO can exploit rich scattering environment without being negatively affected by multipath.

For this reason, MIMO schemes up to 4x4 are defined in the standard.

MIMO can be used to provide both spatial multiplexing and space-time coding.

Spatial MultiplexingSpatial Multiplexing Space Time CodingSpace Time Coding

x1x2x3

y1y2y3

MIMOMIMO

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Network Architecture EvolutionBased on the requirements of reduced latency and cost for Long Term Evolution,

it is natural to consider system architectures that contain a reduced number of network nodes along the data path. This would reduce both the overall protocol-related processing as well as the number of interfaces, which in turn reduces the cost of implementation and interoperability testing.

E-UTRAN

The E-UTRAN consists of eNBs, providing the E-UTRA user plane and control plane protocol terminations towards the UE. A new interface (X2) has been defined between eNodeB, working in a meshed way (meaning that all NodeBs may possibly be linked together).

The main purpose of this interface is to minimize packet loss due to user mobility. As the terminal moves across the access network, unsent or unacknowledged packets stored in the old eNodeB queues can be forwarded or tunnelled to the new eNodeB thanks to the X2 interface.

S1 S1X2X2

Network EvolutionNetwork Evolution

eNB eNB

eNB

MME/UPE MME/UPE

S1

X2

X2

X2

Evolved Packet Core

E-UTRAN

19



Network Architecture EvolutionFrom a high-level perspective, the new E-UTRAN architecture is actually moving

towards WLAN network structures and WiMAX Base Stations functional definition.

eNodeB – as WLAN access points – support all Layer 1 and Layer 2 features associated to the E-UTRAN OFDM physical interface, and they are directly connected to network routers. There is no more intermediate controlling node (as the 2G/BSC or 3G/ RNC was).

This has the merit of a simpler network architecture (fewer nodes of different types, which means simplified network operation) and allows better performance over the radio interface.

Such architecture design has the Such architecture design has the approach in functional distribution as approach in functional distribution as that used in the evolution to HSPA that used in the evolution to HSPA ““oneone--tunneltunnel”” PS core network PS core network architecture.architecture.

Network EvolutionNetwork Evolution

eNB eNB

eNB

MME/UPE MME/UPE

S1

X2

X2

X2

Evolved Packet Core

E-UTRAN

20



LTE-SAE Architecture

21



The E-UTRAN consists of eNBs, providing the E-UTRA user plane (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE.

The eNBs are also connected by means of the S1 interface to the EPC (Evolved Packet Core), more specifically to the MME (Mobility Management Entity) by means of the S1-MME and to the Serving Gateway (S-GW) by means of the S1-U.

eNB

MME / S-GW MME / S-GW

eNB

eNB

S1 S1

S1 S1

X2

X2

X2

E-UTRAN

E-UTRAN Architecture

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From a functional perspective, the eNodeB supports a set of legacy features, all related to physical layer procedures for transmission and reception over the radio interface:

Modulation and de-modulation.

Channel coding and de-coding.

Besides, the eNodeB includes additional features, coming from the fact that there are no more Base Station controllers in the E-UTRAN architecture:

Radio Resource Control

Radio Mobility management

Radio interface full Layer 2 protocol

The eNodeB also implements Distributed RRM funct. e.g.:Set-up/Management/Release of the signaling and the transport bearers

Admission Control

Load Balancing, Inter Cell Interference Coordination (ICIC)

Subscriber Type

auto-configuration/auto-optimization

E-UTRAN Architecture: eNodeB

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A new concept characterizing LTE is the auto-configuration/auto-optimization of the network (SON, Self Organizing Networks) in order to reduce the cost and the effort related to the network management

Self-configuration: auto-configuration of the eNBs by means of automatic procedures (mostly performed in the pre-operational phase)

Basic set up (authentication, downloading of the eNB sw, IP address, S1 set up, ….)

Initial Radio configuration (Neighbour list setup, coverage/capacity related parameter configuration)

ANR: Automatic Neighbour Relation (R8). When the eNB detects (from the terminal report) a cell not included within its own Neighbour List, it includes this cell in the list and sets up the X2 intf toward the related eNB

Self-optimization: utilization of the performance measurement/parameters found by the UE and eNB for the auto-tuning of the network. These procedures are performed in the operational state, that is when the RF interface is “switched on”

Coverage and Capacity Optimisation, Load Balancing, Mobility Robustness,….

E-UTRAN Architecture: eNodeB & SON

24



E-UTRAN Architecture: Radio protocols

User plane: the protocol stack comprises PDCP, RLC, MAC and PHY sublayers(terminated in eNB on the network side) The PDCP, RLC and MAC perform the functions of header compression, ciphering, ARQ, scheduling and HARQ.

Control plane: the protocol stack comprises NAS, (terminated in MME), RRC, PDCP, RLC, MAC and PHY sublayers (terminated in eNB).

eNB

PHY

UE

PHY

MAC

RLC

MAC

PDCPPDCP

RLC

eNB

PHY

UE

PHY

MAC

RLC

MAC

MME

RLC

NAS NAS

RRC RRC

PDCP PDCP

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E-UTRAN Architecture: L3 radio protocolsLayer 3 is composed by the RRC (Radio Resource Control) that is terminated in the eNB on the network side

Broadcast of System Information related to the non-access stratum (NAS) and to the the access stratum (AS)

Paging

Establishment, maintenance and release of an RRC connections

Security functions including key management

Establishment, configuration, maintenance and release of point to point Radio Bearers (RB)

Mobility functions including: Inter-cell handover, UE cell selection and reselection

QoS management functions

UE measurement reporting and control of the reporting

The main layer 3 functions are:

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E-UTRAN Architecture: L2 radio protocols

Layer 2 is split into Medium Access Control (MAC), Radio Link Control (RLC) and Packet Data Convergence Protocol (PDCP).

The multiplexing of several logical channels (i.e. radio bearers) on the same transport channel (i.e. transport block) is performed by the MAC sublayer.

In uplink and downlink, only one transport block is generated per TTI in the non-MIMO case.

Layer 2 Structure for DL(user plane)

Segm.ARQ

Multiplexing UE1

Segm.ARQ...

HARQ

Multiplexing UEn

HARQ

BCCH PCCH

Scheduling / Priority Handling

Logical Channels

Transport Channels

MAC

RLC Segm.ARQ

Segm.ARQ

PDCPROHC ROHC ROHC ROHC

Radio Bearers

Security Security Security Security

...

ROHC = robust header compression

Ciphering

27



E-UTRAN Architecture: L1 radio protocols

Layer 1 model for DL-SCH

The physical-layer model for Downlink Shared Channel (DL-SCH) is described in the Figure.

Processing steps that are configurable by higher layers, are highlighted in blue colour.

CRC

RB mapping

Coding + RM

Data modulation

Interl.

CRC

Resource mapping

Coding + RM

QPSK, 16QAM, 64QAMData modulation

Interleaving

HARQ

MA

C s

ched

uler

N Transport blocks(dynamic size S1..., SN)

Node B

Redundancy fordata detection

Redundancy forerror detection

Multi-antennaprocessing

Resource/powerassignment

Modulationscheme

Redundancyversion

Antennamapping

HARQ info

ACK/NACK

Channel-stateinformation, etc.

Antenna mapping

CRC

RB mapping

Coding + RM

Data modulation

Interl.

CRC

Resource demapping

Decoding + RM

Data demodulation

Deinterleaving

HARQ

UE

HARQ info

ACK/NACK

Antenna demapping

Errorindications

CRC

RB mapping

Coding + RM

Data modulation

Interl.

CRC

Resource mapping

Coding + RM

QPSK, 16QAM, 64QAMData modulation

Interleaving

HARQ

MA

C s

ched

uler

N Transport blocks(dynamic size S1..., SN)

Node B

Redundancy fordata detection

Redundancy forerror detection

Multi-antennaprocessing

Resource/powerassignment

Modulationscheme

Redundancyversion

Antennamapping

HARQ info

ACK/NACK

Channel-stateinformation, etc.

Antenna mapping

CRC

RB mapping

Coding + RM

Data modulation

Interl.

CRC

Resource demapping

Decoding + RM

Data demodulation

Deinterleaving

HARQ

UE

HARQ info

ACK/NACK

Antenna demapping

Errorindications

28



E-UTRAN/SAE Architecture

GERAN

GxRx

SGiS5

X2

eNB

S10S11

S1-U

S1-MME

S3

S6a

S12

S4

UTRAN

ServingGateway

PDNGateway

PCRF

2G/3GSGSN

MME

Operator IP Services(e.g. IMS)eNB

HSS

E-UTRAN

eNB: evolved NodeBMME: Mobility Management Entity (similar to the control part of a SGSN)Serving GW: local anchor point for intra-LTE and inter-3GPP mobility (similar to the UP part of a SGSN)PDN GW: access gateway to a Packet Data Network (similar to a GGSN)SGi: access point to the Internet/Intranet (equivalent to the Gi interface of the GPRS)PCRF: Policy Control and Charging (PCC) Rules Function

This architecture allows for independent scaling and growth of throughput traffic and control signal processing and operators can also choose optimized topological locations of nodes within the network in order to optimize the network in different aspects.

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E-UTRAN/SAE Architectural issues

System optimized for broadband data transmission

PS domain onlyAlways on approach: at the Attach UE receive an IP address and one (or some) default bearer

Logical split between Mobility Management Entity (MME) and User Plane nodes (Serving Gateway and PDN Gateway)

Different implementation options in the co-location of logical entities are feasible

E-UTRAN is characterized by a flat architecture. Only two logical interfaces are defined (S1 and X2)

QoS is still based on the concept of EPS bearer but a label based approach is defined and Network Initiated sessions have a predominant role

Procedures for interworking with non 3GPP access technologies

30



LTE numerology

31



An Orthogonal Frequency Division Multiple Access (OFDMA) scheme is

employed for downlink (DL) transmission.

Scalable-OFDM (S-OFDM) technology is employed: the sub-carrier spacing Δf

is fixed and equal to 15 KHz, independently from the transmission

bandwidth so that the number of subcarriers is proportional to the

transmission bandwidth.

(16.67/512)(16.67/384)(16.67/256)(16.67/128)(16.67/64)(16.67/32)Extended

(4.69/144) × 6,(5.21/160) ×1

(4.69/108) × 6,(5.21/120) × 1

(4.69/72) × 6,(5.21/80) × 1

(4.69/36) × 6,(5.21/40) × 1

(4.69/18) × 6,(5.21/20) × 1

(4.69/9) × 6,(5.21/10) × 1*NormalCP length

(μs/samples)

7/6

Number of OFDM symbols per sub frame

(Normal/Extended CP)

132190160130115176Number of occupied sub-carriers

204815361024512256128FFT size

30.72 MHz(8 × 3.84 MHz)

23.04 MHz(6 × 3.84 MHz)

15.36 MHz(4 × 3.84 MHz)

7.68 MHz(2 × 3.84 MHz)3.84 MHz

1.92 MHz(1/2 × 3.84

MHz)Sampling frequency

15 kHzSub-carrier spacing1.0 msSubframe duration

20 MHz15 MHz 10 MHz5 MHz2.5 MHz1.25 MHzTransmission BW

LTE Numerology

32



An important characteristic of the LTE radio interface is that the frame

duration and Transmission Time Interval (TTI) are harmonized with those of

UMTS/HSDPA system.

In particular the frame duration is equal to 10 ms while the sub-frame period,

which corresponds to the Transmission Time Interval (TTI), is equal to 1 ms

(compared to the 2 ms of HSPA).

Also the sampling frequency of the baseband (BB) signals are harmonized: for

UMTS/HSPA the baseband signal is sampled at 3.84 MHz, while for LTE the

baseband sampling frequency is equal to (n/m)x3.84 where n and m are

integer factors that depend on the LTE channel bandwidth.

These features reduce the complexity and the cost of dual mode terminals

that will support both radio interfaces.

LTE Numerology

33



The useful part of the OFDMA symbol (e.g. not considering the cyclic prefix) has a duration, equal to the inverse of the subcarrier spacing:

The duration of the complete OFDMA symbol including the cyclic prefix (CP), which is introduced to avoid intersymbol interference (ISI) among consecutive OFDMA symbols, is equal to:

where Tcp is the duration of the cyclic prefix. In the LTE standard two CP lengths (normal and extended) have been standardized in order tofacilitate the deployment in environments characterized by different values of delay spread. The normal CP has a duration of 4.69 μs that corresponds to a transmission overhead %, while the extended CP has a duration of 16.67 μs that corresponds to an overhead of about %.

LTE Numerology

s 7.6615000

11 μ==Δ

=f

Tb

cpbs TTT +=

7100 =⋅= bcp TTη

25=η

34



LTE peak data rates

Downlink (20 MHz, code rate 1.0, 64-QAM) • 153.1 Mbit/s with 2×2 MIMO

• 306.2 Mbit/s with 4×4 MIMO

Uplink (20 MHz, code rate 1.0, Single transmit antenna) • 52.8 Mbit/s with 16-QAM

• 79.2 Mbit/s with 64-QAM

LTE bandwidth [MHz] 1.25 2.5 5 10 15 20Number of PRB 6 12 25 50 75 110

Number of control symbols per PRB 2 2 2 2 2 2Number of data subcarriers per PRB 58 58 58 58 58 58

Modulation 6 6 6 6 6 6Number of TX antennas 4 4 4 4 4 4

DL Peak Throughut [Mbit/s] 16.7 33.4 69.6 139.2 208.8 306.2

LTE bandwidth [MHz] 1.25 2.5 5 10 15 20Number of PRB 6 12 25 50 75 110

Number of control symbols per PRB 1 1 1 1 1 1Number of data subcarriers per PRB 60 60 60 60 60 60

Modulation 6 6 6 6 6 6Number of TX antennas 1 1 1 1 1 1

UL Peak Throughut [Mbit/s] 4.3 8.6 18.0 36.0 54.0 79.2

BUT with 2x2 MIMO in the 5MHz bandwidth the DL peak throughput would be similar to HSPA+

35



Details in 3GPP TS 36.306

Downlink capabilities

Uplink capabilities

UE Category

Maximum number of bits of an UL-SCH

transport block transmitted within a

TTI

Peak Throughput supported by the

UE [Mbit/s]

Category 1 5032 5.032 Category 2 25008 25.008 Category 3 50000 50 Category 4 50000 50 Category 5 75056 75.056

16-QAM only

Support of 64-QAM

4 Rx antennas

UE categories

UE Category

Maximum numberof DL-SCH transportblock bits received

within a TTI

Peak Throughputsupported by the

UE [Mbit/s]

Maximum numberof supported layers

for spatialmultiplexing in DL

Category 1 10040 10.04 1Category 2 50000 50 2Category3 100000 100 2Category4 150112 150.112Category5 300064 300.064 4

2

36



In 3GPP Long Term Evolution:

Orthogonal Frequency Division Multiple Access (OFDMA) is to be used in downlink direction

Single Carrier Frequency Division Multiple Access (SC-FDMA) is to be used in the uplink direction

OFDM in 3GPP Long Term Evolution

DownlinkDownlink Multiple access is achieved in OFDMAOFDMA by assigning subsets of subcarriers to individual users. The subcarrier spacing in the OFDM downlink is 15 kHz and there is a maximum of 2048 subcarriers available. The transmission is divided in time into time slots of duration 0.5 ms and subframes of duration 1.0 ms. A radio frame is 10 ms long. Supported modulation formats on the downlink data channels are QPSK, 16QAM and 64QAM.

UplinkUplink SCSC--FDMAFDMA was chosen in order to reduce Peak to Average RatioPeak to Average Ratio (PAR), which has been identified as a critical issue for use of OFDMA in the uplink where power efficient user-terminal amplifiers are required. Another important requirement was to maximize the coverage. For each time interval, the base station scheduler assigns a unique time-frequency interval to a terminal for the transmission of user data, thereby ensuring intra-cell orthogonality.

37



LTE downlink physical layer

38



High resistance to multipath propagation

Low implementation complexity (IFFT/FFT)

Sharp power spectrum decrease at the band edges

Inter-Symbol Interference (ISI) is eliminated at the receiver by removing the

cyclic prefix (i.e. no need for channel equalizers or Rake receivers)

Space-time processing operations performed independently for each sub-

carrier (lower receiver complexity that single carrier transmission)

High Peak to Average Power Ratio (PAPR)

Power amplifiers with high linearity are required (critical issue on the terminal side)

Sensitivity to frequency offset and phase noise

Advantages

Disadvantages

frequency

sub-carriersfΔ

Power spectrum)( fX

Orthogonal Frequency Division Multiplexing (OFDM)

39



LTE frame structures

Downlink and uplink transmission are organized into radio frames with duration Tf = 10 ms. Two radio frames structures are supported

Type 1 frame structure → Applicable to FDD or Half Duplex FDD

Type 2 frame structure → Applicable to TDD

Type 1 frame structure

The alternative frame structure has been defined to facilitate the coexistence with the 1.28 Mchip/s UTRA TDD system (i.e. the TD-SCDMA standard primarily adopted in China).

0.5 ms

One radio frame = 10 ms

Half-frame = 5 ms

Subframe = 1 ms

#0 #2 #3 #4

DwPTSGP

UpPTS


40



Each Type 1 radio frame consists of 20 slots each of length Tslot = 0.5 ms.

A subframe is defined as two consecutive slots where subframe j consists of slots 2j and 2j+1

For FDD duplexing, downlink and uplink transmission are separated in the frequency domain and both the downlink and uplink frame is composed by 10 subframes of 1 ms each.

Slot period equal to 0.5 ms

Two cyclic prefix lengths : normal and extended

Number of OFDM symbols per slot : 7 (normal CP) or 6 (extended CP)


41



Slot structure in a Type 1 frame:

20481

2048 ⋅Δ==

fT

T symbs

sampling time = 32.6 ns

fΔ = subcarrier spacing = 15 KHz

symbT = OFDM symbol duration = 66.6 μs

=sT


Symb 0 Symb 1 Symb 2 Symb 3 Symb 4 Symb 5

Tslot = 0.5 ms

Tsymb = 66.7 μsTCP = 16.6 μs

Extended CP

Symb 6 Normal CPSymb 5Symb 4Symb 3Symb 2Symb 1Symb 0

TCP = 4.69 μsTCP = 5.21 μs

Symb 0 Symb 1 Symb 2 Symb 3 Symb 4 Symb 5

Tslot = 0.5 ms

Tsymb = 66.7 μsTCP = 16.6 μs

Extended CP

Symb 6 Normal CPSymb 5Symb 4Symb 3Symb 2Symb 1Symb 0

TCP = 4.69 μsTCP = 5.21 μs

42



Physical Resource Block (PRB): is the smallest unit of bandwidth assigned by the scheduler at physical level. One PRB is composed by a set of 12 adjacent subcarriers (180 KHz) allocated on a slot-by-slot basis (0.5 ms).

Resource element (RE): each subcarrier in the resource grid

84 REs are contained in one “PRB FDD frame type 1 normal cyclic prefix”

Physical Resource Block (PRB)Resource Element (k,l)

RBSCN subcarriers

RBSC

DLRB NN ⋅ subcarriers

DLsymbN

OFDMsymbols

l=0

l = 1−DLsymbN

k=0 k= 1−⋅ RBSC

DLRB NN

Slot

freq

time

Physical Resource elements and blocks (PRB)

43



In the following table is represented the number of PRB per slot as a function of E-UTRA channel bandwidths:

The minimum size of the physical resources that can be allocated corresponds to the minimum TTI, i.e. one subframe of 1 ms.

Therefore, the quantum of resources that can be allocated corresponds to two PRBs, e.g. 14 OFDM symbols (in case of normal CP, or 12 for the extended CP) of 12 subcarriers (180 kHz).

Physical Resource elements and blocks (PRB)

Channel bandwidthBW [MHz] 1.4 3 5 10 15 20

Number of active PRBsper slot (NRB) 6 15 25 50 75 100

44



Resource allocation for DL Control Channels

The main DL control channels are formed by aggregation of Control Channel Elements (CCE).

Each CCE is, in turn, an aggregation of 9 RE Group (REG) distributed over 1,2 or 3 consecutive OFDM symbols in the beginning of each subframe.

Each REG consists of 4 consecutive REs that are “not used for other purposes”.

This means that 4 REs in a REG need not be strictly consecutive, since some REs are “consumed” by antenna Reference Signals.

45



DL Control ChannelsDL control signalling is located in the first n OFDM symbols (n ≤ 3) of a subframe and consists of:

• Control Format Indicator (CFI), which indicates the amount of resources devoted to control channel use. CFI is mapped to the Physical Control Format Indicator Channel (PCFICH).

• HARQ Indication (HI), which informs of the success of the uplink packets received. The HI is mapped on the Physical HARQ Indicator Channel (PHICH).

• Downlink Control Information (DCI), which controls with different formats basically all the physical layer resource allocation in both uplink and downlink direction and has multiple formats for different needs. The DCI is mapped on the Physical Downlink Control Channel (PDCCH)

Time

Freq

uenc

y 180

kHz

Control Data

46



PDCCH resource allocation from PCFICH

47



LTE Physical Channels (DL)Physical broadcast channel (PBCH)

Mapped to four subframes within a 40 ms interval

It carries the system information needed to access the system, such as RACH parameters.

• Physical control format indicator channel (PCFICH)

• Informs the UE about the number of OFDM symbols (1-3) used for the PDCCHs(i.e. for control information that can vary between 1 and 3 for each 1 ms subframe). It is transmitted in every subframe in the first symbol of the subframe and occupies 4 REGs (16 REs). It exact allocation is cell specific and calculated by the UE using the Physical Cell Identity (PCI).

• Physical downlink control channel (PDCCH)

• Informs the UE about the resource allocation and H-ARQ information related to DL-SCH and PCH. Carries the uplink scheduling grant. The DCI mapped on the PDCCH has different formats and depending on the size DCI istransmitted using one or more Control Channel Elements (CCEs). It is mapped in the first n OFDM symbols (n ≤ 3) of a subframe.

eNB

UE

PBCHPCFICHPDCCH

48



LTE Physical Channels (DL)

Physical downlink shared channel (PDSCH)

Carries the DL-SCH. It uses the remaining REs after the allocation of PCFICH, PDCCH, PHICH and DL RSs. Thus not all the 84 REs in a PRB can be used for actual data transmission.

Physical multicast channel (PMCH)

Carries the MCH

Physical Hybrid ARQ Indicator Channel (PHICH)

• Carriers ACK/NACKs in response to uplink transmissions. It is located in the first symbol of the subframe and occupies 3 REGs (12 REs). The resources for the PHICH are configured on semi-static basis, i.e. the UE knows where to look for it (in terms of Res)

eNB

UE

PDSCHPMCHPHICH

49



LTE Physical Channels (UL)

Physical uplink shared channel (PUSCH)

Carries the UL-SCH

Physical uplink control channel (PUCCH)

Carries ACK/NAKs in response to downlink transmission

Carries Scheduling Request (SR)

Carries CQI reports

Physical random access channel (PRACH)

Carries the random access preamble

eNB

UE

PUSCHPUCCHPRACH

50



LTE Channels Architecture

RRC

PDCP

RLC

MAC

SRB SRB SRB SRB SRB DRB DRB

CONTROL PLANE USER PLANE

SCHEDULING PRIORITY

MUX/DEMUX

HARQ HARQ

BCCH PCCH CCCH DCCH MCCH MTCH DTCH

BCH RACH PCH DL-SCH MCH UL-SCH

PBCH PRACH PHICH PCFICH PDCCH PDSCH PMCH PUSCH PUCCH

LogicalChannels

TransportChannels

PhysicalChannels

IETF

51



DL Reference Signals

The Reference Signal (RS) consist of known reference symbols inserted in the first and third last OFDM symbol of each slot.

Time

Freq

uenc

y

1 ms

180

kHz

Normal CP

RS sequence is a pseudo random

sequence that is a function of the slot

number and cell ID

504 unique cell IDs (PCI)

WCDMA has 512 P-SC

52



DL Reference Signals for one or two antennas case

0=l0R

0R

0R

0R

6=l 0=l0R

0R

0R

0R

6=l

One

ant

enna

por

tTw

o an

tenn

a po

rts

Resource element (k,l)

Not used for transmission on this antenna port

Reference symbols on this antenna port

0R

0R

0R

0R

0R

0R

0R

0R 1R

1R

1R

1R

1R

1R

1R

1R

53



UE measurements

For the UE the following measurements are to be performed inside the LTE system:

Reference Signal Received Power (RSRP), which for a particular cell is the average of the power measured (and the average between receiver branches) of the resource elements that contain cell-specific reference signals.

E-UTRA Received Signal Strength Indicator (RSSI), which is the total received wideband power on a given frequency. E-UTRA RSSI is not reported by the UE as an individual measurement (as indicated in the early versions of specs until June 2008), but it is only used in calculating the RSRQ value inside the UE.

Reference Signal Received Quality (RSRQ) is the ratio of the RSRP and the E-UTRA (RSSI), for the reference signals.

54



LTE uplink physical layer

55



Single Carrier FDMA

Single carrier FDMA (SC-FDMA) accommodates multiple-user access

It was chosen in order to reduce Peak to Average Ratio (PAR), which has

been identified as a critical issue for use of OFDMA in the uplink where

power efficient amplifiers are required.

Another important requirement was to maximize the coverage. For each

time interval, the base station scheduler assigns a unique time-frequency

interval to a terminal for the transmission of user data, thereby ensuring

intra-cell orthogonality.

Slow power control, for compensating path loss and shadow fading, is

sufficient as no near-far problem is present due to the orthogonal uplink

transmissions.

DFTSub-

carrierMapping

IFFTCP

insertion

(size M) (size N≥M)

56



Subcarrier mapping

Two subcarrier mapping schemes analyzed during the standardization

• Distributed

• Localized

3GPP decided to use only the localized mapping for LTE uplink in order to better exploit Adaptive Modulation and Coding rather than to increase the frequency diversity.

Distributed Mapping Localized Mapping

57



Uplink Transmission SchemeBased on single-carrier FDMA, UL sub-carrier spacing Δf = 15 kHz.

While the maximum transmission bandwidth is up to 20 MHz, the minimum transmission bandwidth is down to 180 kHz, equal to the 12 x 15 kHz sub-carriers in the downlink direction or, rather, one resource block.

One PRB corresponds to 12 adjacent sub-carriers during one slot period (0.5 ms). The number of resource blocks can range from 6 (1.25 MHz) to 100 (20 MHz)

58



MIMO in LTE

59



Multiple antenna techniques in LTE

Support for multi-antenna techniques is an integral part of LTE still from the Release 8

Performance requirements set assuming all terminals support at least two receiving antennas

LTE terminals are expected to support all the MIMO techniques present in the 3GPP standard

An important aspect is the selection of the proper MIMO technique that the network must perform for each user depending on its channel conditions (e.g. SINR value, user speed, channel correlation) Adaptive MIMO

The following MIMO techniques have been standardized in the Release 8 of 3GPP LTE :

• Transmit Diversity (SFBC)• Cyclic Delay Diversity (CDD)• Spatial Multiplexing with a single user (SU-

MIMO)• Spatial Multiplexing with two users (MU-MIMO)• Linear Precoding• Beamforming

LTE downlink (Release 8)

• UE antenna selection (optional)• Receiver diversity at the eNode B• Multi-User MIMO (MU-MIMO)

LTE uplink (Release 8)

60



Transmit Diversity (SFBC, space frequency block coding)

Increases the robustness of the radio link -> suitable for cell edge users; enhance coverage

Open loop technique (no feedback from the UE) -> suitable for high mobility users

Based on the application of a space-time code (Alamouti) over two adjacent OFDM subcarriers

Provides spatial diversity for transmissions for which channel dependent scheduling is not possible or convenient

Primarily intended for common downlink channels. Can also be applied to user-data transmission (e.g. VoIP), where the low data rates may not justify the overhead associated with channel-dependent scheduling

t

f

*2S−

2S1S

*1S

A1

A2

MIMO 2×n

Alamouti codeon two adjacentOFDM subcarriers

MIMO 4×n

Alamouti codeapplied on each

couple of antennas

61



CDD is an open-loop transmit diversity technique (also applicable together with SM

technique)

Introduces virtual echoes that increase the frequency selectivity of the channel and thus

it is particularly useful in flat channels characterized by low frequency diversity (e.g.

small delay spread channels)

Open loop technique -> suitable for high speed users

Consists in the application of a linear phase shift (as a function of frequency) on the data

subcarriers transmitted from the various antennas. The linear phase shift is applied at

the transmitter before the IFFT operation and has different slopes for the transmit

antennas

Cyclic Delay Diversity (CDD)

Channel response seen by the UE without CDD Channel response seen by the UE with CDD

62



Spatial Multiplexing

Increases the peak data rate -> suitable for users in good channel conditions (high

SINR, near eNodeB)

Based on the simultaneous transmission of multiple parallel data streams over the

same time-frequency resources -> the stream separation is performed a the UE

receiver

The data streams can be directed to a single UE (SU-MIMO) or multiple UEs (MU-MIMO)

63



Linear precoding

Increases the robustness of the radio link -> suitable for both cell edge users (single

stream transmission) and users in good channel conditions (multiple stream transmission)

Closed loop technique -> suitable for low mobility users

Consists in the multiplication of the streams to be transmitted by a precoding vector or

matrix

The optimum precoding vector/matrix is selected by the UE from a finite set, called the

“codebook”, known to both the receiver and the transmitter

The UE receiver sends as feedback to the eNode B the index of the selected matrix (PMI)

Codebook index

Number of layers υ

1

0 ⎥⎦

⎤⎢⎣

⎡11

21

1 ⎥⎦

⎤⎢⎣

⎡−11

21

2 ⎥⎦

⎤⎢⎣

⎡j1

21

3 ⎥⎦

⎤⎢⎣

⎡− j1

21

Codebook for 2 Tx antennas

eNodeB

Traffic channel

Estimate CSI1Select matrix

Estimate CSI2Select matrix

PMI

Traffic channel

PMI

UE1UE2

Note: the PMI index may change with frequencyPMI

64



Beamforming

Exploits antenna arrays with element spacing of half wavelength (λ/2) or less

The signal weighting is performed at baseband level by means of suitable complex

weights that permit the maximization of the array gain in the direction of the useful signal and, at the same time, to place a minimum of the radiation diagram in the direction of the interfering signals

For FDD duplexing the Direction of Arrival (DoA) can be estimated from the uplink sounding signals (i.e. long-term DoA based beamforming is one candidate for FDD)

BaseStation 1

BaseStation 2

Mobile Phone 1

Mobile Phone 2 Increase coverage and capacity by means

of spatial filtering of the co-channel

interference

65



Effect of channel correlation on MIMO performance

The main idea behind MIMO is to establish independent parallel channels (at the same frequency) between multiple transmit and receive antennas

Due to fading correlation, the number of independent parallel channels is reduced

Fading correlation is determined by antenna distance, Angle Spread (AS) of electromagnetic waves, number of received echoes and presence of LoS (Line of Sight)

SU-MIMO (Spatial Multiplexing) is the technique most affected by channel correlation

Fading correlation vs. antenna distance SU-MIMO 4x4 theoretical capacity vs.correlation

66



Adaptive MIMO in LTE

The different MIMO techniques standardized in LTE are optimal in different channel conditions

In particular the selection of the optimum MIMO technique should be performed by the E-UTRAN network taking into account the SINR value (derived from the CSI), channel correlation (derived from the Rank Indicator) and mobile speed (derived from uplink reference signals)

SINR

Fadingcorrelation

low

high

highUser speed

highlow low

medium

mediummedium

Open loop spatial multiplexing

(SU-MIMO, SU-MIMO with CDD)

Transmit diversity (SFBC) Single layer precoding

Closed loop spatial multiplexing

(SU-MIMO with precoding)

Open Loop

MIMO techniques

Closed Loop

MIMO techniques

MU-MIMOSINR

Fadingcorrelation

low

high

highUser speed

highlow low

medium

mediummedium

Open loop spatial multiplexing

(SU-MIMO, SU-MIMO with CDD)

Transmit diversity (SFBC) Single layer precoding

Closed loop spatial multiplexing

(SU-MIMO with precoding)

Open Loop

MIMO techniques

Closed Loop

MIMO techniques

MU-MIMO

67



Adaptive MIMO

An important feature of an LTE network is the selection of the proper MIMO technique for each user depending on its channel conditions (e.g. SINR value, user speed, channel correlation)

• Extended Pedestrian A – v = 3 km/h

• High channel correlation

68



Adaptive MIMO

Impact of user speed on open and closed loop MIMO

techniques

Impact of channel correlation on SU-MIMO performance

69



Impacts of MIMO techniques on network performanceSeveral antenna techniques supported; each antenna technique is suitable for a particular channel condition:

Open loop or closed loop

Single data stream/multiple data streams

Network performance are affected by channel conditions:

SINR cell edge or close to eNodeB

User speed

Channel correlation

An important aspect is the selection of the proper MIMO technique that the network must perform for each user depending on its channel conditions Adaptive MIMO

70



QoS in LTE

71



QoS model in E-UTRAN

72



The EPS QoS architecture (TS 23.401) has been substantially simplified as compared to legacy network. The bearer model itself is very similar to the GPRS bearer model, but it has fewer layers. EPS supports the always-on concept. There are two types of bearer: default and dedicated bearer.


With a default bearer is meant basic IP-connectivity between UE and some external Packet Data Network (PDN). Such bearer does not guarantee any level of QoS and is typically used for signalling purposes only (or service with very low requirements). The EPS QoS architecture has been substantially simplified as compared to legacy network.

With a dedicated bearer is meant any other bearer, besides the default one, that is established between the UE and the same PDN. There may be zero, one or more dedicated bearer active for each PDN (but only one default bearer).

73



In E-UTRAN, a bearer can be GBR (Guaranteed Bit Rate) or non-GBRIn case of GBR bearer, the transmission resources needed to supply a minimum guaranteed bit rate in the access network are permanently assignedThe non-GBR bearers do not have any resource permanently assignedA default bearer is always non-GBR.

Subscription data in the HSS sets a maximum limit, for each PDN, on the bit rate that the network should provide for a non-GBR bearer. This parameter is called the Aggregate Maximum Bit Rate (AMBR). It limits the aggregate bit rate that can be expected to be provided across all non-GBR bearers and across all PDN connections of the same APN. Each of those non-GBR bearers could potentially utilize the entire APN AMBR, e.g. when the other non-GBR bearers do not carry any traffic

The UE-Aggregate Maximum Bit Rate (UE-AMBR) is subscription parameter stored in the HSS that limits the aggregate bit rate that can be expected to be provided across all non-GBRbearers of a UE. Each of those Non GBR bearers could potentially utilize the entire UE AMBR, e.g. when the other Non GBR bearers do not carry any traffic. GBR bearers are outside the scope of UE AMBR.

The GBR and MBR denote bit rates of traffic per bearer while UE-AMBR/APN-AMBR denote bit rates of traffic per group of bearers.


74



AMBRNote: A default bearer is always non-GBR

75



Both default and dedicated bearer are also associated with Uplink and Downlink TFT (Traffic Flow Template) and a set of QoS parameters.

The TFT identifies the traffic flows (SDF, Service Data Flow) mapped on the EPS bearer. It is a specification of a packet filter to be applied to all IP packets sent over a given bearer. A TFT could, for example, only allow TCP/IP packets or UDP/IP packets or only packets with a certain port or destination address (or any specific combination of port, address and protocol)

The set of QoS parameters is composed by:QCI (QoS Class Identifier), a scalar that identifies the type of traffic forwarding in the access network (related to the scheduling mechanisms)

ARP (Allocation and Retention Priority), a value of priority that can be used by the eNB in order to decide which bearer to release in case of lack of resources

GBR (Guaranteed Bit Rate) e MBR (Maximum Bit Rate), only defined for the GBR bearers. Note that a Release 8 network is not required to support differentiation between the MBR and GBR, and the MBR value is always set to equal to the GBR.

The QoS parameters are translated, in a implementation dependent way, into radio interface parameters that are passed to the eNB packet scheduler (MAC) in order to fullfill the requirement of the established QoS context.


76




77



Each EPS bearer is associated to a QCI, a scalar valueThe QCI is a pointer to a set of parameters that control the type of traffic

forwarding on the eNBsThese parameters, that can be access-specific, are pre-configured by the operator on the access nodes (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration)

Some values of QCI are standardized and are related to a set of characteristics specifying the expected behavior in the link between the UE and the gateway

The QCI Characteristics consist of Bearer Type (GBR/non-GBR, implicit in the QCI value), Packet Delay Budget (PDB) e Packet Loss Rate (PLR)

The QCI Characteristics are not signaled on the S1 interface

It is up to the operator/manufacturer to choose how to configure the eNBs in order to guarantee that the SDF associated to a specific QCI are used in a way respectful of the related QCI Characteristics

The concept of QCI

78



QCI definition (TS 23.203)

79



QCI mapping (TS 23.401)

80



QCI and QoS attributes

81



Rx Signalling(service

infomation)

E2e QoS in case of an IMS/PCC based service

In the EPS bearer establishmentThe eNB sets up the Radio Bearer based on QCI and GBRUL packet filters are set up at the UE and DL packet filters on the PDN GW,

S-GW/P-GW(PCEF)

eNode B

MME

UE PCRFS1-u

S1-c S10S7

ApplicationFunction

1

PCRF defines PCC rules and enforces them on P-GW

The PCC rule is linked to a QCI

2PCC Rule

QCI, GBR, MBR, ARP

The PDN GW derives QCI, GBR, MBR and ARP

from PCC rule

3

44

SAE Bearer establishment 4

82



Deployment strategies

83


Telecom Italia strictly confidential and proprietary83

LTE traffic steering (VoIP): SR-VCC

In LTE many services, such as the legacy based on CS domain (e.g. voice, videocall) or the new ones (presence, chat, gaming, ecc.) will be based on IMS architecture (PS domain).

Within IMS a new functionality called Single Radio Voice Call Continuity (SR-VCC) provides the ability to transition a voice call from the VoIP/IMS packet domain to the legacy circuit domain. The solution does not require UE capability to simultaneously signal on two different radio access technologies, therefore it is called a Single Radio Solution and it is specified in 3GPP TS 23.216.

The selection of the domain or radio access is under the network control in SR-VCC and SR-VCC enhanced MSC Server (called ‘S-IWF’) deployed into the CS core network. This architecture has been defined to enable re-use of already deployed CS core network assets to provide the necessary functionality to assist in SR-VCC.

By the way during the initial phases of LTE deployment, IMS is likely not to beavailable and it will be necessary to introduce proper traffic management policiesin order to provide continuity for voice services towards UTRAN and GERAN domains.

84



LTE traffic steering (VoIP): CSFB

In order to support the steering of voice service from LTE to UTRAN/GERAN in an early network without IMS a functionality called “CS fallback” (CSFB) has beenintroduced in core network in order to support the change from PS to CS domain and the change of RAT.

CS fallback requires interworking between RAN (for HO management) and corenodes (e.g. MME and MSC) introducing an impact on signalling and call setupdelay.

Two options exist for CSFB to UTRAN

Based on PS handover (included in 3GPP rel 8): Normal PS HO to UTRAN must be supported (pre 3GPP rel-8).

Based on RRC Connection Release with Redirect (recently added in 23.272, CR in S2-094200): In case PS HO is not supported. No upgrade of UTRAN or SGSN needed.

This issue does not apply for LTE data cards but only for voice capablehandheld. For this reason within 3GPP R8 new features for interRAT management were introduced, such as dedicated priority, subscriber type, RAT indicator, thatguarantee a greater flexibility to the operator for traffic steering based on service type and user profile.

85



Dedicated priority information for camping

The possibility to implement selective camping based on terminal basisis possible thanks to the feature of dedicated RAT/Frequency priority, introduced in 3GPP Rel-8 for GERAN, UTRAN and E-UTRAN [3GPP TS 25.304, 36.304].

With this functionality is possible to signal to the terminal the camping priorities that overwrite the ones broadcasted by the serving cell.

Moreover thank to the Subscriber Profile ID (SPID) for RAT/FrequencySelection Priority (RFSP) is possible to set a parameter on the UE profilethat allow a customization of camping priorities for each RAT.

It is important to note that the SPID functionality is optional for the core network and the commercial availability shall be verified with the vendors.

86



Dedicated priority: example

87



An example of EPS introduction guidelines

Mobile Broadband selected areas Progressive coverage extension

2010-2012 2012-2014 > 2014

Low mobility LTE data cards

LTE

2G/3G/HSPA

Overlay E-UTRAN network

Non ToIP LTE handsets

2G/3G/HSPA

ToIP LTE handsets

LTE

2G/3G/HSPA

Converged core network

Progressive migration towards a converged core network.

LTE LTELTELTE

88




The initial deployment of LTE will target data services

In an early phase no IMS/VoIP will be provided on EPS; voice services will be ensured by CS domain and GERAN/UTRAN accesses

UTRAN coverage will further improve and network stability will be better than LTE for a long time

Best LTE/UTRAN usage for voice-capable handset could be as follows:

UTRAN layer is used as reference layer

Access to LTE is subject to the requested service (3G->LTE PS redirection)

89




The introduction of EPS may be divided in three phases

Phase 1 (2010-2012)

The EPS scenario will be focused on data services on data cards. Mobility Management will consider a scenario of low mobility and bidirectional PS handover with 2G/3G coverage. The LTE network will be in overlay with the 2G/3G PS network

Phase 2 (2012-2014)

Handsets without ToIP. In such a scenario CS fallback for Voice CS + SMS is required to support such services on UTRAN. Specific camping strategies could be envisaged to reduce CSFB occurrences of voice-centric users to limit impacts on call setup delay. Progressive migration towards an EPC-GPRS integrated core network is expected together with first availability of interworking functions with non-3GPP accesses

Phase 3 (>2014)

Handsets with ToIP. In such a scenario SR-VCC or PS HO may be deployed to support voice service continuity. Core network complete migration is expected

90



A possible strategy for EPS introduction (LTE-SAE)

2014: handset 2G/3G/LTE with ToIPSR-VCC supportCore network complete migration

2010-2012: data card 2G/3G/LTEData servicesNetwork architecture with dedicated EPC nodes deployed in addition to the already in use GPRS core networkService continuity with 2G/3G coverageLow MobilityFrequencies 2.5 GHz and BW 10-20 MHz

2012-2014: handset 2G/3G/LTE without ToIPCS fallback for Voice CS + SMSProgressive migration towards an integrated core network 2G/3G/LTE with combined nodes MME/SGSN and PGW/SGW/GGSNFirst network availability of interworking functions with non-3GPP accesses

2010-2012 2012-2014 > 2014

Type of deployment

Mob

ile B

road

band

sel

ecte

d ar

eas

Prog

ress

ive

cove

rage

ex

tens

ion

LTE: Long Term EvolutionEPC: Evolved Packet CoreCS: circuit switchingMME: Mobility Management EntityPGW: Packet GatewaySGW: Serving GatewaySR-VCC: Single Radio Voice Call Continuity

LTE phase 1

LTE phase 2

LTE phase 3

91



LTE trials

92



The LTE/SAE Trial Initiative (LSTI) is an open initiative driven by vendors and operators launched in May 2007. Its objectives are mainly to: drive industrialization of 3GPP LTE/SAE technology, demonstrate LTE/SAE capabilities against 3GPP and NGMN requirements and stimulate development of the LTE/SAE ecosystem.

Representatives of LSTI are from all across LTE’s global ecosystem counting, for the time being, 42 members


The information on NGMN/LSTI activities are confidential and under NDA

93




IOTIODT TrialsProof of Conceptpartially

compliantCompliant

over key subset Compliant Compliant+form factor UE

Vendor + test UE

or UE partner Vendor +

UE partner pairsMultiple Partners Vendors and UE

Operator + Vendor +UE partner

Applications

Towards standards compliancy and commercial conditions

The LSTI work activities are based on three different phases namely: Proof of Concept (PoC), Interoperability Development Testing (IODT) and Interoperability Testing (IOT) and, finally, Friendly Customer Trials (FCT).

94




LSTI Activity Timing

2007 2008 2009 2010

Proof of Concept

IODT

IOT

Friendly Customer Trials

PR/Marketing

preparation

preparation

preparation

95



PoC (examples of proof points):Peak data rates: LSTI measured results from lab and field align with 3GPP LTE design targets, easily surpassing the requirements (100/50Mbps for DL/UL)

Latency: measured reaction times of unloaded Base stations all meet 3GPP/NGMN target of 10ms (cell loading and weak signal conditions result in slight increases)

Power control: initial LSTI results demonstrate power control is working to maintain desired received power at the eNodeB

Speeds: the LSTI’s initial results demonstrate support of up to 350km/h (little impact to throughput is seen at 120km/h compared to 30km/h)


Multi UEMIMOSingle CellSingle UE

Multi cell

FieldLab

96



Friendly Customer Trials:In particular Friendly Customer Trials represent the final stage in testing the technology before it is commercially rolled out. Operators will be running field trials, based on bilateral agreements with selected vendors, testing mobile broadband applications, using pre-commercial form factor terminals, connected to a cluster of pre-commercial eNodeBs and EPC.

During January 2010 LSTI members will share their first results on

Latency and State transitionThroughput and Capacity

The next delivery are expected in March and June. The LTE/SAE Trial Initiative shall complete its mission by H1 2010


- Run Friendly Customer Trials

Q1 Q2 Q3 Q4

M.10M.11- Negotiate agreements

- Define test strategy & tests plans

- Define Trial technical framework

2009Q1 Q2 Q3 Q4

2008Q1 Q2 Q3 Q4

Friendly Customer Trial Milestones

M.12a M.12b

2010

97



TI’s LTE trials

98



“Prototypal” trial with Ericsson (Nov 2008)

Tests with “Berta” terminal provided by Ericsson

Using 20 MHz bandwidth it was possible toreach 10 Mbps as maximum throughput mainly due to processing constraints

Tests with “Big UE” terminal provided by Ericsson

Using 20 MHz bandwidth it was possible toreach 158 Mbps as maximum throughput

99



“Prototypal” trial with Huawei (Sept 08-Feb 09) Phase 1Lab testing only

Tests were focused on LTE/EPC aspects and X2/S1 procedures

Max # of sim. users = 3

System instability affected dramatically the investigation on the radio technology. It was not possible to get a full picture of the system from the point of view of radio part.

Control Plane procedures on interfaces showed a good level of compliancy with the standard. Because of the prototypal status of the solution, UE were kept always in active mode and Attach/Detach were executed manually.

LTE UE

Prototype

Multimedia client

Internet

eNodeB

Prototype

SAE Prototype

S1 SGi

R R

VOD Server

FTP/HTTP Server

IMS CSCF

100



Second phase of lab testing held at Huawei’s premises in Shanghai.

Test were focused on radio aspects, such as SIMO, MIMO and capacity

The system was more stable with respect to the previous phase. However some feature were still unavailable/unstable:

Uplink scheduling;

MIMO SM.

During the trial an in-field demo was held:

Only one eNodeB was used

One route close to the eNodeB was considered (75% of time in LOS)

Services: videostreaming, video call & UDP traffic.

“Prototypal” trial with Huawei (May 09) Phase 1bis

101



For phase 2 lab (July) and in field testing (from August) was carried out on the same topics of phase 1 (i.e. LTE & EPC, X2 & S1)

This trial is currently on going with another handset vendor

A press release was held in October 2009

Trial with pre commercial equipment Huawei (July’09-Dec’09) –Phase 2

…and for the future?

102



Next trial plans

NSN: starting from Q1 2010

Ericsson: to be confirmed.

ALU lab and in field Q1-Q2 2010

103



LTE trial with Huawei

104



Trial Architecture

TITOLO PRESENTAZIONE, ALLINEATO IN BASSO E A DESTRA, MASSIMO 2 RIGHE

105Telecom Italia strictly confidential and proprietary

During performance tests and demo activities up to four UEs were connected over the air to the eNodeBs installed in different places in Turin The setup of the trial was made of six sites: four macro sites equipped with three sectors each and two micro sites in via Garibaldi and piazza Statutoequipped with one sector each. An additional indoor site was also installed inside the Auditorium of via Reiss’ site for demo purpose. Finally the core network was hosted inside the test plant of via Borgaro’s premiseDuring performance tests and demo activities up to four UEs (provided by Huawei ) were connected over the air to the eNodeBs.

Trial Architecture

01

2 34

5

9

1011

6

78

1

2

34

512

613

1 Site number

2 Azimuth and PCI

01

2 34

5

9

1011

6

78

1

2

34

512

613

1 Site number

2 Azimuth and PCI



In field measurements



A Test Object List (TOL) was agreed with the vendor. The tests were grouped into 4 categories:Preliminary drive test.

The purpose of these tests was to characterize according to LSTI requirements the coverage of the cell used for test.

Stationary testLatency. The purpose of these tests was to evaluate the end to end round trip delay in the considered trial configuration. Taking into account the trial architecture, these tests could be used to evaluate the radio interface latency. Moreover, tests on C-plane latency (idle to active time) were also performed. These tests were carried out with different packet sizes and in different interference conditions.Throughput. The purpose of these tests was to evaluate the throughput achieved in different interference conditions and with different services.

Mobility testThroughput. The purpose of these tests was to evaluate the LTE performance in mobility (e.g. FTP/UDP throughput, handover KPIs, etc). The UE was moving under the LTE coverage considering different interference conditions (e.g. loaded/unloaded system).

Demo activities. The purpose of these activities was to show LTE performances when up to three UEs were downloading data from an indoor cell end a fourth UE was moving inside a van under an outdoor cell coverage.

Test object list



The purpose of these activities was to show LTE performances when up to three UEs were downloading data from an indoor cell and a fourth UE was connected to an outdoor cellThe scenario considered during the demo was the following:

The core network and the demo eNodeB BBU were hosted in Telecom Italia’s test plant;The demo eNodeB RRU was hosted in Via Reiss Romoli premise. The connection BBU-RRU was made using a commercial naked optical fibre;Site 1 was equipped with cells having PCI=1 and PCI=2;FTP server, Video On Demand (VoD) server and VideoConferencing (VC) server were connected to core network. The VoD streaming were coded at 30Mbps (UDP traffic), while the VC required 5Mbps both in uplink and downlink. The FTP service was used on all UEs to load the downlink in order to fill the sector capacity of the demo site;Three UEs camped under the demo cell were loaded with the following services:

UE2: FTP download + VoD download;UE3: FTP download + VoD download;UE4: FTP download + VC.

One UE was moving within the coverage area of Site 1 (see Figure 5-47, Figure 5-48 and Figure 5-49) with the following services:

UE1: VC;

Demo results



Mobility tests with unloaded system UDP downlink (throughput distribution)



Mobility tests with unloaded system UDP downlink (RSRP distribution).



In the configuration considered for the demo, the number of PDCCH symbols was reduced in favour of the PDSCH that could have more symbol to transmit data. With this setting, more radio resources were available for user traffic and a cell throughput capacity of about 140Mbps was reached (45-46Mbps for each of the three UEs). Anyway, this configuration had some stability issues since a script potentially risky for the system had to be used for fixing the number of RBs to 32 for each UEs and for reducing the output power of RRU in order to improve the quality of the RF signal. Without this script a maximum throughput of about 100Mbps was reached (34mbps for each UEs)

Demo results

113



LTE advanced

114



4G: IMT advanced

The ITU-R process towards IMT-Advanced

IMT-Advanced Systems & Key features of IMT-Advanced

IMT-Advanced Minimum Requirements

Evaluation methodology & External Evaluation Groups

The 3GPP candidate: LTE-Advanced

LTE-Advanced Timeline

LTE-Advanced Requirements

New features of LTE-Advanced

115



IMT-Advanced Systems

ITU coordinates efforts of government and industry and private sector in the development of a global broadband multimedia International Mobile Telecommunication system, known as IMT.

Since 2000, the world has seen the introduction of the first family of standards derived from the IMT concept: IMT-2000.

IMT-Advanced systems are mobile systems that include the new capabilities of IMT that go beyond those of IMT-2000. Such systems provide access to a wide range of telecommunication services including advanced mobile services, supported by mobile and fixed networks, which are increasingly packet-based.

IMT-Advanced systems support low to high mobility applications and a wide range of data rates in accordance with user and service demands in multiple user environments, providing a global platform on which to build the next generations of mobile services.

http://www.itu.int/ITUhttp://www.itu.int/ITU--RR

ITUITU--R M.1645R M.1645: “Framework and overall objectives of the future development of IMT-2000 and systems beyond IMT-2000”

116



Key features of IMT-Advanced

The following key features enable IMT-Advanced to address evolving user needs (in

line with user trends and technology developments).

A high degree of commonality of functionality worldwidecommonality of functionality worldwide while retaining the flexibility to support a wide range of services and applications in a cost efficient manner.

Compatibility of services within IMTCompatibility of services within IMT and with fixed networks.

Capability of interworking with other radio access systemsinterworking with other radio access systems.

High qualityHigh quality mobile services.

User equipment suitable for worldwide useworldwide use.

User-friendly applications, services and equipment.

Worldwide roamingWorldwide roaming capability.

Enhanced peak data ratesEnhanced peak data rates to support advanced services and applications.

Source: ITU-R M.1645

117



Steps in radio interface development process:

Step1 and 2

No.1 No.2 No.3 No.4 No.5 No.6 No.7 No.8 No.9

Step 3(0)

(1)

(20 months)

Step 4(8 months)

(16 months) (2)Steps 5,6 and 7

(3)Steps 8

(4)(12 months)

(20 months)

WP 5D meetings

Step 1: Issuance of the circular letterStep 2: Development of candidate RITs and SRITsStep 3: Submission/Reception of the RIT and SRIT proposals

and acknowledgement of receiptStep 4: Evaluation of candidate RITs and SRITs

by evaluation groups

Step 5: Review and coordination of outside evaluation activitiesStep 6: Review to assess compliance with minimum requirementsStep 7: Consideration of evaluation results, consensus building

and decision Step 8: Development of radio interface Recommendation(s)

Critical milestones in radio interface development process:(0): Issue an invitation to propose RITs March 2008(1): ITU proposed cut off for submission October 2009

of candidate RIT and SRIT proposals

(2): Cut off for evaluation report to ITU June 2010(3): WP 5D decides framework and key October 2010

characteristics of IMT-Advanced RITs and SRITs(4): WP 5D completes development of radio February 2011

interface specification Recommendations

2008 2009 2010No.10

2011

IMT-Advanced A2-01

Evaluations(ExternalExternalevaluationsevaluations)

SubmissionsNOTE: Submissionsare accompaniedwith self evaluationsself evaluations

The IMT-A timeline

The ITU-R schedule spans over the 2008-2011 timeframe.

118



ITUITU--R M.2133R M.2133: “Requirements, evaluation criteria and submission templates for the development of IMT-Advanced”

ITU-R minimum requirementsThe minimum requirements for IMTminimum requirements for IMT--AdvancedAdvanced Radio Interface Technologies (RITs) were

concluded in ITU-R WP5D meeting in July 2008.

Several of the requirements have different values for different test environmentstest environments.

An RIT can enter the process to become an IMT-Advanced technology if it fulfils the minimum requirements for at least one test environment. However, it cannot be accepted as an IMT-Advanced technology unless it fulfils the minimum requirements in at least three of the test environments.

The test environments have been chosen to model and investigate different typical deployments.

Evaluation of candidate IMT-Advanced RIT/SRITs will be performed in selected scenarios of the following test environments:

Base coverage urban: an urban macro-cellular environment targeting continuous coverage for pedestrian up to fast vehicular users.

Microcellular: an urban micro-cellular environment with higher user density focusing on pedestrian and slow vehicular users.

Indoor: an indoor environment targeting isolated cells at offices and/or in hotspot based on stationary and pedestrian users.

High speed: macro cells environment with high speed vehicular and trains.

119



All the requirements in just one glance…

120



The 3GPP candidate: LTE-Advanced

The ITU has coined the term IMT Advanced to identify mobile systems whose capabilities go beyond those of IMT 2000. In order to meet this new challenge, 3GPPs Organizational Partners have agreed to widen 3GPP’s scope to include systems beyond 3G.

In 2008, 3GPP held two ““3GPP IMT3GPP IMT--Advanced WorkshopsAdvanced Workshops””:

Shenzhen, April 2008Shenzhen, April 2008 (www.3gpp.org/ftp/workshop/2008-04-07_RAN_IMT_Advanced/)

Prague, May 2008Prague, May 2008 (www.3gpp.org/ftp/tsg_ran/tsg_ran/TSGR_40/LTE-Advanced%20workshop/)

The goal of these workshops was to investigate what are the main changes that could be brought forward to evolve the eUTRA Radio Interface as well as the eUTRAN in the context of IMT-Advanced.

In particular, the LTELTE--Advanced Study Item (SI)Advanced Study Item (SI) was initialized in order to study the evolution of LTE, based on a new set of requirements. This initiative has been collecting operator's and manufacturer's views in order to develop and test innovative concepts that will satisfy the needs of the next-generation communications.

The requirements were gathered in “Requirements for Further Advancements for E-UTRA”. The resulting Technical Report 36.913Technical Report 36.913 was published in June 2008 and a liaison was sent to ITU-R covering the work in 3GPP RAN on LTE-Advanced towards IMT-Advanced.

3GPP will be contributing to the ITU-R towards IMT-Advanced via its proposal for LTE-Advanced.

121



3/08 6/08 12/08 3/09 5/09 9/09 12/09 3/109/08

LTE-Advanced SI Approved

3GPP LTE-Advanced

Early Submission to

ITU-R

Steps 1 & 2Circular Letter & Development of Candidate RITs

3/08 to 10/09

IMT-AdvancedEvaluation Group(s) Formed

(notify ITU-R)

3GPP

Initiate 3GPP LTE-Advanced

Self-Evaluation

3GPP LTE-Advanced Final Submission to

ITU-R including Updated Technical

Submission & Required Self-

Evaluation

LTE-Advanced Specifications

3GPP LTE-Advanced Complete Technical

Submission to ITU-R

Step 3Submission3/09 to 10/09

Step 4Evaluations1/09 to 6/10

3/08 6/08

10/09

10/09

6/103/09

ITU-R

3/09


to ITU-R~ Jan 2011

Evaluation of ITU-R

Submissions

EvalReports

ITU-R Circular Letter 5/LCCE/2

Process & Timelines

ITU-R Circular Letter Addendum

5/LCCE/2 + Requirements& Submission

Templates Cutoff for Evaluation Reports

to ITU-RJune 2010

INDUSTRY

RAN #41 RAN #42 RAN #43RAN #39 RAN #44RAN #40 RAN #45

WP 5D #1 WP 5D #2

WP 5D #4

WP 5D #8

WP 5D #6

WP 5D #4 WP 5D #6

RAN #47RAN #46

[~Release 10 ][~RAN #50 12/10]

6/09WP 5D #5

10/08WP 5D #3

ITU-REvaluation

Criteria

3GPP work on ITU-R Step 2Technology Development

3GPP work on ITU-R Step 3Technology Submission

3GPP Q&A with evaluation

groups (as required)

3/08 6/08 12/08 3/09 5/09 9/09 12/09 3/109/08

LTE-Advanced SI Approved

3GPP LTE-Advanced

Early Submission to

ITU-R

Steps 1 & 2Circular Letter & Development of Candidate RITs

3/08 to 10/09


(notify ITU-R)


(notify ITU-R)

3GPP

Initiate 3GPP LTE-Advanced

Self-Evaluation

3GPP LTE-Advanced Final Submission to

ITU-R including Updated Technical

Submission & Required Self-

Evaluation


3GPP LTE-Advanced Complete Technical

Submission to ITU-R

Step 3Submission3/09 to 10/09

Step 4Evaluations1/09 to 6/10

3/08 6/08

10/09

10/09

6/103/09

ITU-R

3/09


to ITU-R~ Jan 2011


to ITU-R~ Jan 2011

Evaluation of ITU-R

Submissions

EvalReports

ITU-R Circular Letter 5/LCCE/2

Process & Timelines

ITU-R Circular Letter Addendum

5/LCCE/2 + Requirements& Submission

Templates Cutoff for Evaluation Reports

to ITU-RJune 2010

INDUSTRY

RAN #41 RAN #42 RAN #43RAN #39 RAN #44RAN #40 RAN #45

WP 5D #1 WP 5D #2

WP 5D #4

WP 5D #8

WP 5D #6

WP 5D #4 WP 5D #6

RAN #47RAN #46

[~Release 10 ][~RAN #50 12/10]

6/09WP 5D #5

10/08WP 5D #3

ITU-REvaluation

Criteria

3GPP work on ITU-R Step 2Technology Development

3GPP work on ITU-R Step 3Technology Submission





3GPP LTE-Advanced timeline w.r.t. ITU-R

Source: 3GPP RP-080651

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Data plane : <10 ms (round trip delay)

Control plane : 50 ms (idle to active state)

Data plane : 10 ms (round trip delay)

Control plane : 100 ms (idle to active state)Latency

Up to 100 MHz (2)Up to 100 MHz (2)Up to 20 MHzUp to 20 MHzBandwidth

1.2 (1x2 SIMO) (1)

2.0 (2x4 MIMO)

2.4 (2x2 MIMO) (1)

2.6 (4x2 MIMO)

3.7 (4x4 MIMO)

0.74 (1x2 SIMO) (4)

1.69 (2x2 MIMO) (3)

1.87 (4x2 MIMO)

2.67 (4x4 MIMO)

Average Spectrum efficiency

[bit/s/Hz/cell]

15 bit/s/Hz30 bit/s/Hz≈ 4.3 bit/s/Hz (1x2 SIMO)

≈ 8.6 bit/s/Hz (Virtual MIMO)≈ 16.3 bit/s/Hz

Peak Spectrum efficiency

500 Mbps (4x4 MIMO, low mobility)

1 Gbps (8x8 MIMO, low mobility)

86.4 Mbps (1x2 SIMO)

172 Mbps (Virtual MIMO)

326.4 Mbps (4x4 MIMO)

172.8 Mbps (2x2 MIMO) Peak data rate

UplinkUplink DownlinkDownlink

Next Releases LTE-A (3GPP targets in TR 36.913) Release 8 LTE

The Table summarizes some requirements of the Release 8 LTE system and of the LTE-Advanced

(LTE-A) that is targeted for the next releases of the 3GPP specifications(1).

(1) 3GPP TR 36.913 , “Requirements for LTE-Advanced”

(2) Achievable also by means of Carrier Aggregation

(3) R1-072444, “Summary of Downlink Performance Evaluation”. Ericsson, TSG-RAN WG1 #49

(4) R1-072261, “LTE Performance Evaluation - Uplink Summary”. Vodafone, TSG-RAN WG1 #49

Requirements: R8 and beyond

123



New features of LTE-AdvancedMain technical features under discussion:

Support of wider bandwidth

Carrier aggregation, where two or more component carriers, each with a bandwidth up to 20 MHz, are aggregated, is considered for LTE-Advanced in order to support downlink transmission bandwidths larger than 20 MHz, e.g. 100 MHz.

Extended Multi-Antenna configurations

Extension of LTE downlink spatial multiplexing to up to eight layers is considered. For the uplink spatial multiplying to up to four layers is considered.

Coordinated Multiple Point transmission and reception

This feature is considered as a tool to improve the coverage of high data rates, the cell-edge throughput and/or to increase system throughput

Relaying functionality

Relaying is considered for LTE-Advanced as a tool to improve e.g. the coverage of high data rates, group mobility, temporary network deployment, the cell-edge throughput and/or to provide coverage in new areas.

3GPP TR 36.8143GPP TR 36.814, “Further Advancements for E-UTRA Physical Layer Aspects”, R9

124



Obrigado pela sua atenção

125



References

126



References(available at http://www.3gpp.org/ftp/specs/latest/../)TS 36.101 Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception .

TS 36.104 Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station (BS) radio transmission and reception .

TS 36.201 Evolved Universal Terrestrial Radio Access (E-UTRA); Long Term Evolution (LTE) physical layer; General description .

TS 36.211 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation .

TS 36.212 Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding

TS 36.213 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures .

TS 36.214 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer - Measurements .

TS 36.300 Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 .

TS 36.302 Evolved Universal Terrestrial Radio Access (E-UTRA); Services provided by the physical layer .

TS 36.304 Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode .

TS 36.314 Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Layer 2 -Measurements .

TS 36.321 Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification .

TS 36.322 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Link Control (RLC) protocol specification.

TS 36.323 Evolved Universal Terrestrial Radio Access (E-UTRA); Packet Data Convergence Protocol (PDCP) specification .

TS 36.331 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification .

TS 36.401 Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Architecture description .

TS 36.410 Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 layer 1 general aspects and principles .

TS 36.424 Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 data transport .

TS 36.509 Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC); Special conformance testingfunctions for User Equipment (UE) .

TR 36.814 Evolved Universal Terrestrial Radio Access (E-UTRA); Further advancements for E-UTRA Physical layer aspects .

TR 36.902 Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Self-configuring and self-optimizing network (SON) usecases and solutions .

TR 36.913 Requirements for further advancements for Evolved Universal Terrestrial Radio Access (E-UTRA) (LTE-Advanced) .

127



mmmm…..Eu não

entendo…

For clarifications:

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aillant@

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italia.i

t

Mobile:

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