GRANDMETRIC GUIDEPAPER

LTE-Advanced Pro A Short Excursion

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Everybody is currently talking about the upcoming 5G era but during this race to get to 5G, we should not forget

about the evolution of LTE that’s taking place. One of the main reasons for this is the potential 5G requirement to

have tight integration with the evolved LTE. With Rel-13 of 3GPP standards getting frozen a new step has been taken

in the evolution of LTE, under the name of “LTE-Advanced Pro”. We provide an overview of this new “LTE creature”

herein. This Guidepaper starts with the features covered under the umbrella of LTE-Advanced Pro and is divided into

the ones standardized within Rel-13 and Rel-14. Further enhancements are also shortlisted and outlined in taking

LTE-Advanced Pro to Rel-15. Next chapters elaborate some of the features in more details

including: the integration of LTE-Advanced Pro with WiFi at the RAN level, LTE interface version for unlicensed spec-

trum access (Licensed Assisted Access), and LTE feature for massive MTC, namely Narrowband-IoT. Finally, the

Guidepaper is summarized by showing the evolution of the system features, starting from LTE through LTE-Advan-

ced Pro along with the changes in the theoretical peak throughput values.

Executive summary

2

3

2 Executive summary

4 LTE-Advanced Pro – What is it?

4 LTE-Advanced Pro Rel-13 features

5 LTE-Advanced Pro v.2 – enhancements within Rel-14

6 Rel-15 enhancements to LTE-Advanced Pro

7 LTE-Advanced Pro RAN level integration with WiFi

8 LTE access to unlicensed spectrum

10 Narrowband IoT (NB-IoT) for massive MTC

11 The evolution of LTE: from LTE Rel-8 through LTE-Advanced to LTE-Advanced Pro

11 Timeline

11 Main features

13 Magic throughput values

15 Summary

17 Glossary

19 References

20 About the author

Contents

LTE-Advanced ProWhat is it?

4

LTE-Advanced Pro is a new marker for LTE starting with Rel-13

onwards. According to 3GPP, “the new term is intended to mark the

point in time where the LTE platform has been dramatically enhanced

to address new markets as well as adding functionality to improve

efficiency” [1]. Some of the main features for initial LTE-Advanced Pro

release are summarized below followed by enhancements from the

Rel-14 and Rel-15 Work Items.

LTE-Advanced Pro Rel-13 features The first release of LTE-Advanced Pro was frozen in March 2016. It was brought to reality with quite extensive set

of new functionalities as compared to LTE-Advanced. They are summarized below.

Massive CA - extends carrier aggregation towards higher number of aggregated bands and towards the use of

unlicensed spectrum for mobile networking. Massive CA enables up to 32CCs and thus theoretically provides up to

640MHz of aggregated bandwidth for a single device, while still fulfilling backwards compatibility with LTE Rel-8

channel bandwidths.

Dual Connectivity (DC) – spectrum aggregation in inter-site scenario, where a macro-cell serves as a mobility

anchor, whereas the additional radio link provided by Small Cell acts as a local capacity booster. DC enables to

switch User Plane links among available SCs, whereas the user’s context is maintained by the overlay macro-cell. In

contrary to CA, DC scheme, instead of aggregating MAC layer transport blocks, the PDCP Packet Data Units are

combined, thus omitting the requirement for low latency and allowing non-ideal backhaul for Small Cell

connectivity.

Indoor positioning – improvements for location performance (especially for emergency calls) using WiFi, collabo-

rative positioning and beacon systems.

LTE-WLAN Aggregation (LWA) - the Carrier Wi-Fi serves as a capacity booster, using radio level integration for

uniform user experience provisioning over the Wi-Fi radio. In LWA, UE is configured by the eNB to utilize radio resour-

ces of both, LTE and WLAN.

5

Licensed Assisted Access (LAA) - aggregates the licensed LTE carrier (serving as a mobility and signaling anchor

- PCell) with SCell using the new LTE frame format over the unlicensed 5GHz ISM band.

Device-to-device (D2D) - direct communication between devices assisted by network utilizing sidelink using new

transport and physical channels.

MTC enhancements – addressing low complexity MTC with focus to define a low complexity UE category type that

supports reduced bandwidth (operation with 1.4MHz), reduced transmit power, reduced support for downlink

transmission modes, ultra-long battery life via power consumption reduction techniques and extended coverage

operation (up to 15dB). Additionally, NB-IoT has been specified as a modified LTE interface for even lower channel

bandwidth for the operation in 180kHz spectrum chunks.

3D/Full Dimension-MIMO - allows to use elevation beamforming enhancing the horizontal beam steering, and

using up to 64 antenna ports with further outlook towards high frequencies for 5G.

LTE-Advanced Pro v.2 – enhancements within Rel-14

The work for Rel-14 has just been completed, with the new SI/WI targeting improvements and new features for

LTE-Advanced Pro. Some of the interesting functionalities are summarized below.

enhanced LAA (eLAA) - extends LAA scheme with UL consideration and forward compatibility to enable full

DC-like capabilities for unlicensed spectrum.

enhanced LWA (eLWA) - As LWA standardized within Rel-13, considered DL-only operation, an enhanced LWA

(eLWA) is proposed within Rel-14 to overcome this limitation. The new features in this enhancement include:

addition of UL transmission via WLAN, PDCP optimizations for increased data rates, and SON-related features for

WLANs under eNB coverage.

Vehicluar-to-Vehicular (V2V) – specifies RAN support for V2V operation integrated with Uu interface within or

without network coverage using sidelink including: PHY layer structure, RRM requirements, and L2/L3 protocol

operation.

CP and UP latency enhancements - Shortening TTI down to a single OFDMA symbol and more resource efficient

UL scheduling timing are some examples of the proposed improvements targeting latency reduction.

Light connection – discussion on new intermediate RRC state for keeping UE context alive during short

active/inactive transitions (applicable for massive MTC use case with small data transmission);

Multi-connectivity - is expected to enhance DC, by providing multiple links for a UE in two options. First option

considers configuration of multiple radio links per UE, where only limited, selected set of radio links is active at any

given moment. Alternatively, all of the configured multiple radio links can be active.

6

Rel-15 enhancements to LTE-Advanced ProFurther enhancements for the LTE-Advanced Pro covered within the recently started Rel-15 include the following

Work Items:

1024 QAM for LTE – targets improving the spectral efficiency for LTE small cell deployments using 10 bits per

Resource Element. Some scenarios that can benefit from this high capacity links can be nomadic laptops or indoor

/ outdoor CPEs further delivering connectivity to end-devices via other links.

LAA/eLAA for CBRS at 3.5GHz – the original LAA/eLAA has been standardized within Rel-13 and Rel-14

respectively for purely unlicensed spectrum at 5GHz to ensure coexistence with (mostly) WiFi networks. As the

CBRS (Citizens Broadband Radio Service), specified by FCC for USA, allows for 3-tier spectrum usage model (with

incumbent, licensees and unlicensed uses), the Rel-15 aims at adjusting the frame structure 3 to operate in 3500-

-3700MHz band using the LAA and eLAA framework.

Enhancing LTE Operation in Unlicensed Spectrum – following the LAA feature specified within Rel-13 for DL

operation in unlicensed spectrum and eLAA feature from Rel-14 to cover both DL and UL, Rel-15 is aiming at impro-

ving the performance of LTE in the unlicensed spectrum specifying e.g., the support of autonomous uplink access

within frame structure 3 absorbing the knowledge from the latency reduction Work Item.

Enhancements to V2X – cover the support of advanced V2X services (like vehicle platooning, advanced/remote

driving, extended sensors) still being backward compatible with Rel-14 V2X (for the delivery of safety messages).

Some of the objectives include improvements for PC5 link, like: aggregation of up to 8 PC5 carriers under CA featu-

re; 64QAM; transmit diversity; or short TTI.

Further Enhancements to NB-IoT – the NB-IoT baseline has been specified with the first release of LTE-Advanced

Pro within Rel-13. Rel-14 defined the enhancements to the baseline including the NB-IoT support for positioning,

multi-cast and non-anchor carrier operation. The interesting improvements within Rel-15 include: small-cell support

for NB-IoT, and TDD support for in-band, guard-band and standalone operation modes.

7

WiFi was considered as an offload mechanism for LTE from its

introduction, within Rel-8. However, the initial interworking was very

loose, with the WiFi connected to the EPC add on functions and a

“deeply hidden” CN “suggests” to the UE for moving the traffic to the

WLAN. As we progress with the standardization, the integration of the

carrier-WiFi to the cellular is more and more tight, the Rel-13 specifies

a RAN-level interworking within LTE-Advanced Pro.

The following mechanisms have been standardized within Rel-13 under the LTE-WiFi RAN-level integration

framework [2]:

LTE-WLAN Aggregation (LWA): is basically an evolution of Dual Connectivity (as specified within Rel-12), where the

secondary link is provided by the WiFi AP. This is very tight resource aggregation, where a single DRB can be either

switched very fast between LTE and WiFi link or split and provided simultaneously by the two RATs. However, in

order to be able to do that, the WiFi network needs to be upgraded with the WT logical entity and support Xw

interface. Additionally, the UE needs to be upgraded with LWAAP protocol, to be able to properly route the PDCP

PDUs coming from WiFi link.

RAN-Controlled LTE-WLAN Interworking (RCLWI): is also based on WT and Xw interface upgrade of the WiFi

network for control signaling, however, the UP bearers are not going through the LTE eNB, but rather through a CN

with WiFi legacy link. This is rather a bearer handover (or an offload) than an aggregation compared to LWA,

however still the UE is controlled by the network to receive the data from WiFi link, instead of taking this decision by

itself. Compared to LWA, this solution doesn’t require the UE upgrade with LWAAP.

LTE-WLAN Radio Level Integration with IPsec Tunnel (LWIP): provides the possibility to aggregate resources from

WiFi and LTE simultaneously (similar to LWA), but without the need to upgrade the WiFi network (i.e., enables use of

the legacy WiFi networks). The WiFi link is managed by the LTE eNB, however instead of the LWA-like flow control

and use of LWAAP, the IPsec tunnel is established between UE and eNB. The split bearer is not possible as the

aggregation is done at IP level.

LTE-Advanced ProRAN level integration with WiFi

8

LTE operation in unlicensed spectrum is not limited to its aggre-

gation with WiFi (as mentioned in the previous chapter). The

other approach to utilize the unlicensed spectrum combined

with the MNO’s operated LTE networks is based on a speciali-

zed version of LTE system to cope with the unlicensed spec-

trum’s requirements. This is referred to as Licensed Assisted

Access (LAA) and has been addressed with the introduction of

LTE-Advanced Pro within Rel-13. There are however, two other

technologies to achieve that, not-standardized by 3GPP, namely

LTE-Unlicensed (LTE-U) and MuLTEfire. Those three “technolo-

gies” enabling the LTE system accessing unlicensed spectrum

are shortly presented below.

Licensed-Assisted Access (LAA) [2], is a 3GPP Rel-13 feature, where the resources from unlicensed spectrum,

handled by the modified version of the LTE radio interface, are aggregated utilizing Carrier Aggregation feature. For

this, the legacy licensed LTE carrier serves as a Primary Component Carrier (PCC), and up to four DL Secondary

Component Carriers (DL SCC) can be used from the 5GHz unlicensed band with the specialized Frame Type 3. The

Rel-14 talks about enhanced LAA (eLAA) that deals with the addition of the UL LAA carriers. To assure “fairness” of

using the unlicensed spectrum, LAA utilizes Listen Before Talk (LBT) mechanism, where the transmitter, prior to

transmission, senses the channel to verify if it’s occupied or free. With this, it can be applied globally, whilst it fulfills

the regulatory requirements.

LTE-Unlicensed (LTE-U) [3], is a proprietary technology (developed before the release of LTE-Advanced Pro), where

the unlicensed spectrum is also aggregated with the licensed spectrum PCC by means of CA. However, the

standard LTE frame type is used, not supporting the LBT scheme. Instead, it uses the Channel Selection and Carrier

Sensing Adaptive Transmission (CSAT), where once the specific channel is empty, the regular LTE transmission is

used. When there are no empty channels, the adaptive duty cycle is used, where the LTE is switched ON and OFF for

specific periods of time with the durations, adapted to the channel occupancy by the other systems. However, due

to no LBT support, it is not allowed in many countries.

LTE accessto unlicensed spectrum

9

MuLTEfire [4], is also a proprietary solution, but reusing LAA and eLAA design with LBT. However it is designed for

a standalone mode, i.e., no licensed PCell is needed. Of course, because of this, the additional aspects need to be

considered for the unlicensed access, like mobility, paging and system information. This allows for using the

unlicensed spectrum with neutral host concept, where multiple operators share the MuLTEfire resources.

10

Narrowband IoT (NB-IoT) for massive MTC

LTE-Advanced Pro has touched the needs of the massive MTC

use cases under the Narrowband Internet-of-Things (NB-IoT) [5]

feature. To address the IoT requirements in this segment

namely, support for: low throughput and sporadic transmission,

limited mobility, large number of devices, low device cost,

enhanced coverage – the PHY layer, protocol stack and signa-

ling procedures has been simplified with respect to the LTE

system design to support low-end devices and decrease

signaling load.

The key aspects of NB-IoT to support low-end IoT devices and services, while reusing LTE infrastructure

include [2]:

PHY layer has been modified for coverage enhancements and power consumption reduction by e.g., reducing

system BW to 180 kHz, reduction of transmission modes and number of antenna ports, reduced TB size,

improved DRX cycles for both connected and idle modes, and single HARQ process for both DL and UL. The

three operation modes have been specified: standalone 180 kHz carrier, LTE guard-band usage, in-band LTE –

using single LTE resource block. The DL supports multi-tone transmission with 12 subcarriers of 15kHz, while

for UL both multi-tone and single-tone operation is possible with both 15kHz and 3.75kHz subcarrier separa-

tion.

System aspects that have been modified with respect to LTE, include: lack of connected mobility support

(assuming the majority of the NB-IoT applications being used by stationary UEs) and system optimizations for

efficient data transmission (also called CP/UP CIoT EPS Optimization Solutions). The CP solution is based on

the concept of UP data transmission over NAS signaling, without establishing of the Data Radio Bearer (DRBs)

and is mandatory solution for NB-IoT UEs. The UP solution on the other end is built upon the idea of holding the

UE context at the eNB when the UE moves to RRC IDLE state, thus decreasing the

signaling overhead when the UE is switching between IDLE and CONNECTED mode with the use of

Resume/Suspend procedure.

¹ 3GPP Rel-13 has also specified the other 2 solutions for IoT, namely LTE-M (enhanced MTC) and EC-GSM

11

After the description of selected LTE-Advanced

Pro features, this chapter highlights an

evolution path of LTE, starting with its

introduction within 3GPP Release 8 back in early

2009, up to LTE-Advanced Pro finalized in March

2016 within Release 13.

TimelineLTE Rel-8 standard was frozen in March 2009. The goal for it was to prepare the system evolution for 4G

requirements imposed by IMT-Advanced. From the technical point of view, it was not a full 4G system.

LTE-Advanced was specified within 3GPP Rel-10. The corresponding standard was frozen in June 2011.

LTE-Advanced was defined to fulfill IMT-Advanced requirements, thus is a 4G technology.

LTE-Advanced Pro name was agreed by 3GPP in October 2015 as a marker for LTE from Rel-13 onwards. The Rel-13

was frozen March 2016. The new name is used to mark a point where significant improvements with regards to

LTE-Advanced are made.

Main featuresRel-8 LTE was initially standardized with the following main set of features:

OFDMA – to allow sharing and assigning resources in time and frequency domain;

MIMO – to natively use space dimension for capacity/coverage improvements;

eNB – a simplified RAN architecture with a single type of node encapsulating features from RNC and NodeB

(from the 3G world);

Operation with FDD and TDD duplex modes;

The evolution of LTE: from LTE Rel-8 through LTE-Advancedto LTE-Advanced Pro

12

Enhanced MIMO with up to 8 antennas at eNB – to improve spectral efficiency;

Heterogeneous Networks (HetNet) – a network with different types of nodes to allow home usage of LTE and

increasing capacity in hotspots. This includes such concepts as HeNB and enhanced ICIC.

SON – introducing automation to network operation in the means of Self-Configuration, Self-Optimization and

Self-Healing;

Multicast Broadcast Multimedia Services – with the Single Frequency Network (SFN) to allow broadcasting the

same service content within different cells using LTE radio;

Extending maximum combined spectrum bandwidth to up to 100MHz (i.e. the use of maximum of 5 CCs with

20MHz each).

LTE-Advanced Pro features set includes the following (similar to above reasoning, for the simplicity purposes,

LTE-Advanced Pro features cover Rel-11 to up to Rel-13):

Enhanced MIMO

Coordinated Multi-Point Transmission/Reception (CoMP) – transmission/reception using different

transmission points to address a single UE to improve cell edge users’ performance;

Full Dimension-MIMO – allow to use elevation beamforming enhancing the horizontal beam steering.

Enhanced PHY layer

Enhanced PDCCH – decreasing the dedicated PHY signaling resources by transmitting resource

allocation messages within data resources;

256QAM – further increasing spectral efficiency to allow transmission of 8 bits per symbol;

Combined operation of FDD and TDD by the means of CA.

Adaptive modulation and coding with QPSK/16QAM/64QAM and turbo codes with variable rates;

Use of flexible spectrum bandwidth with 1.4MHz to up to 20MHz.

LTE-Advanced is defined in 3GPP as Rel-10, but for simplicity, we assume it also incorporates Rel-9 characteristics.

Thus, the combined set of features includes the following:

Carrier Aggregation (CA) – possibility to aggregate multiple Rel-8 Component Carriers (CC) on MAC level to

increase system capacity or user throughput with the scheduling flexibility;

New connectivity methods

Dual Connectivity (DC) – possibility to combine different data links from macro cell and small cell.

It uses the PDCP level aggregation;

Device-to-device (D2D) – direct communication between devices assisted by network by using side-link.

Usage of unlicensed spectrum

Licensed-Assisted Access (LAA) – LTE radio usage within unlicensed 5GHz band with new frame type to

assure fair coexistence with WiFi;

LTE-WiFi Aggregation (LWA) – aggregation of links using both LTE and standard WiFi system where the

data is split on PDCP level.

Magic throughput valuesTo improve the attractiveness of each new system/release (but also to show the maximum capability of the techno-

logy) a maximum theoretical throughput in DL is provided as one of the Key Performance Indicators.

For LTE, the maximum throughput is ~320Mbps, for LTE-Advanced – 3Gbps, and LTE-Advanced Pro is expected to

extend it further to 4Gbps. An interesting question is: where do these magic numbers come from?

Let’s take each of them and try to answer this question with simplified calculations:

LTE maximum throughput

Maximum DL spectral efficiency = 16bits/s/Hz (with 4 spatial streams using 4 antennas and 64QAM – i.e.

6bits/symbol)

Maximum BW size = 20MHz

Maximum throughput = 16bit/s/Hz * 20MHz = 320Mbit/s

LTE-Advanced maximum throughput

Maximum DL spectral efficiency = 30bits/s/Hz (increase in number of antennas by 2, i.e. to 8. However

spectral efficiency is not improved exactly 2x, due to additional pilots needed)

Maximum BW size = 100MHz (5 x 20MHz - maximum of 5 component carriers)

Maximum throughput = 30bits/s/Hz * 100MHz = 3Gbps

13

14

LTE-Advanced Pro maximum throughput

Maximum DL spectral efficiency = 40bits/s/Hz (8/6 * 30bits/s/Hz, i.e. with the introduction of 256QAM,

a maximum of 8bits/symbol can be transmitted instead of 6)

Maximum BW size = 100MHz (Note: further spectrum enhancements are not included here, e.g. 32CC and

unlicensed spectrum usage)

Maximum throughput = 40bits/s/Hz * 100MHz = 4Gbps

LTE evolution is an exciting area where new features are added to improve current system’s performance and

operability, but also to enable new services to be introduced. On the other side, the overall system’s complexity is

increased with the new solutions.

What we can observe by looking at the presented features set, is that the initial macro-network-based LTE using

OFDMA waveform and multi-antenna is evolving towards Heterogeneous Networks increasing used spectrum with

the multi-point connectivity, unlicensed spectrum and automated network operation. In this Guidepaper we have

focused on the 3 areas: LTE integration with WiFi, LTE access to unlicensed spectrum and LTE specialized interface

for MTC application.

Rel-13 brought the different options for the very tight network controlled LTE-WiFi integration. This is to enable

different level of integration and depending on the required WiFi network upgrade and / or UE side upgrade:

LWA is the tightest and most flexible resource aggregation, whereas requires highest level of upgrade.

LWIP allows to use legacy network, still enabling the resource aggregation on the RAN level.

RCLWI on the other hand requires similar upgrade at the network side, but doesn’t require UE upgrade, but

doesn’t allow very tight resource aggregation as the WiFi link is anchored at the CN side.

Speaking of enhancing the LTE framework with the access to the unlicensed 5GHz spectrum there are

3 technologies to do that with slight differences:

LAA is standardized, globally usable technology with LBT scheme, requiring the anchor licensed carrier,

supporting DL (and Rel-14 eLAA considering UL);

LTE-U is non-standardized, non-globally usable technology, but introduced earlier than LAA, and supporting

only DL direction, requiring the anchor licensed carrier;

MuLTEfire is non-standardized, globally usable technology with LBT scheme, operating in standalone mode for

both DL and UL.

Some of the 5G use case requirements are also heavily addressed with the use of legacy system support and

infrastructure. In these considerations, mMTC edge of the “5G service triangle” is addressed by NB-IoT with:

15

Summary

Air interface simplifications for coverage improvements, device simplification, battery consumption

reduction etc.,

System enhancements for (mostly) signaling reduction, UE operation simplification.

If we collect the individual enhancements from this Guidepaper, the evolved LTE moves towards a system with the

following properties:

Use of licensed and unlicensed access;

Aggregation of large portions of spectrum;

Support for multiple links aggregation;

Truly heterogeneous networks with multi-RAT support with a RAN level integration;

Addressing IoT market and D2D support with initial works on V2V;

Enhancing legacy LTE with latency and “connection lightness” improvements

High spectral efficiency with the use of large number of antennas.

And if we take a closer look on these, and compare with some “5G” design concepts, we can notice they look very

close to each other. In our opinion, the main difference comes from the fact that the evolution of LTE towards 5G

design goals is achieved by improvements and enhancements and adding more features, whereas 5G targets a

flexible design where all of the above should be brought together in a native manner.

Note: This guidepaper is based on our entries at Grandmetric blog.

16

3GPP Third Generation Partnership Project

AP Access Point

BW Bandwidth

CA Carrier Aggregation

CBRS Citizens Broadband Radio Service

CC Component Carrier

CIoT ellular Internet-of-Things

CN Core Network

CoMP Coordinated Multi-Point Transmission/Reception

CP Control Plane

CPE Customer Premises Equipment

CSAT Carrier Sensing Adaptive Transmission

D2D Device-to-Device

DC Dual Connectivity

DL Downlink

DRB Data Radio Bearer

DRX Discontinuous Reception

EC-GSM Extended Coverage GSM

eICIC enhanced Inter-Cell Interference Coordination

eLAA enhanced LAA

eLWA enhanced LWA

eNB evolved NodeB

ePDCCH enhanced Physical Downlink Control Channel

EPS Evolved Packet Core

FCC Federal Communications Commission

FDD Frequency Division Duplex

HeNB Home eNB

HetNet Heterogeneous Network

IMT International Mobile Telecommunications

IP Internet Protocol

ISM Industrial, Scientific, Medical

L2/L3 Layer2 / Layer

LAA Licensed Assisted Acces

LBT Listen Before Talk

LTE Long Term Evolution

17

Glossary

LWA LTE-WLAN Aggregation

LWAAP LWA Adaptation Protocol

LWIP LTE-WLAN Radio Level Integration with IPsec Tunnel

MAC Medium Access Control

MIMO Multiple Input Multiple Output

MNO Mobile Network Operator

MTC Machine Type Communications

NAS Non-Access Stratum

NB-IoT Narrowband IoT

OFDMA Orthogonal Frequency Division Multiple Access

PCC Primary Component Carrier

PCell Primary Cell

PDCP Packet Data Convergence Protocol

PDU Packet Data Unit

QAM Quadrature Amplitude Modulation

QPSK Quadrature Phase Shift Keying

RAN Radio Access Network

RAT Radio Access Technology

RCLWI RAN-Controlled LTE-WLAN Interworking

RNC Radio Network Controller

RRC Radio Resource Control

RRM Radio Resource Management

SC Small Cell

SCC Secondary Component Carrier

SFN Single Frequency Network

SI Study Item

SON Self-Organizing Network

TB Transport Block

TDD Time Division Duplex

TTI Transmission Time Interval

UE User Equimpent

UL Uplink

UP User Plane

V2V Vehicular-to-Vehicular

L2/L3 Layer2 / Layer3

LAA Licensed Assisted Access

LBT Listen Before Talk

V2X Vehicular-to-Anything

WI Work Item

WLAN Wireless Local Area Network

18

Air interface simplifications for coverage improvements, device simplification, battery consumption

reduction etc.,

System enhancements for (mostly) signaling reduction, UE operation simplification.

If we collect the individual enhancements from this Guidepaper, the evolved LTE moves towards a system with the

following properties:

Use of licensed and unlicensed access;

Aggregation of large portions of spectrum;

Support for multiple links aggregation;

Truly heterogeneous networks with multi-RAT support with a RAN level integration;

Addressing IoT market and D2D support with initial works on V2V;

Enhancing legacy LTE with latency and “connection lightness” improvements

High spectral efficiency with the use of large number of antennas.

And if we take a closer look on these, and compare with some “5G” design concepts, we can notice they look very

close to each other. In our opinion, the main difference comes from the fact that the evolution of LTE towards 5G

design goals is achieved by improvements and enhancements and adding more features, whereas 5G targets a

flexible design where all of the above should be brought together in a native manner.

Note: This guidepaper is based on our entries at Grandmetric blog.

[1] www.3gpp.org

[2] 3GPP TS 36.300

[3] www.lteuforum.org

[4] www.multefire.org

[5] http://www.3gpp.org/news-events/3gpp-news/1785-nb_iot_complete

19

References

Marcin Dryjanski received his M.Sc. degree in telecommunications from the

Poznan University of Technology in Poland in June 2008. During the past 10

years, Marcin has served as R&D Engineer, Lead Researcher, R&D Consultant,

Technical Trainer and Technical Leader. He has been providing expert level

courses in the area of LTE/LTE-Advanced for leading mobile operators and

vendors. In addition to that, Marcin was a work-package leader in EU-funded

research projects aiming at radio interface design for 5G including FP-7 5GNOW

and FP-7 SOLDER. He co-authored a number of research papers targeting

LTE-Advanced Pro and 5G radio interface design. Marcin is a co-founder of

Grandmetric, heading the field of mobile wireless systems. In this role, Marcin

provides consulting services and training courses in the area of 5G related topics.

Marcin is a co-author of a book entitled "From LTE to LTE-Advanced Pro and 5G",

(by M. Rahnema, M. Dryjanski, published by Artech House), where you can find

more detailed info about the contents provided in this Guidepaper. The book is to

be soon available for purchase at the publisher page: www.artechhouse.com.

To contact Marcin, please write to: marcin.dryjanski@grandmetric.com

20

About the author

Grandmetric is an R&D and training company specializing in Next Generation Networks along with Wireless

Systems based in Poznan, Poland. Our latest research is focused on 5G, Internet-of-Things (IoT) and Network

Security. We actively conduct technology trainings, are engaged in developing latest systems, and consulting

network designs.

Shall you have any enquiries or to schedule a meeting with us, please write at: info@grandmetric.com

Note: ETSI is the copyright holder of LTE, LTE-Advanced and LTE-Advanced Pro Logos. LTE is a trade mark of ETSI. Grandmetric Ltd is authorized to use the LTE,

LTE-Advanced or LTE-Advanced Pro logos and the acronym LTE.

info@grandmetric.com

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