an overview on current trends in mobile communications

Current trends in mobile communicationsAn overview

Francisco J. Escribano, Universidad de Alcala

[email protected]

July 7, 2015

Francisco J. Escribano Current trends in mobile communications July 7, 2015 1 / 81

mailto:[email protected]

Table of contents I

1 Motivation

2 Enabling technologies for XG evolution

3 Current and future MC cellular standards

4 Situation of XG worldwide

5 Business & opportunities

6 Final remarks

7 References


Motivation

Motivation


Motivation

An evolving world I

Figure 1: Source [1].


Motivation

An evolving world II



Motivation

An evolving world III



Motivation

An evolving world IV

Figure 4: The Internet of Things (IoT)! (source [3]).



Enabling technologies for XG evolution

Enabling Technologies for XG

Evolution


Enabling technologies for XG evolution Spread spectrum

Spread spectrum I

−1.5 −1 −0.5 0 0.5 1 1.5

x 106

−10

0

10

20

30

40

50

Normalized frequency

Pow

er S

pect

ral D

ensi

ty

Figure 6: Red: PSD of a binary polar data sequence. Blue:PSD of the spread data sequence with spreading factor 128.

Spread spectrum enabled CDMA (Code Divi-

sion Multiple Access) communications (IS-95,

UMTS).◮ It also enables secure comms.

A first door towards wireless global broadband

comms.◮ WCDMA, Wideband-CDMA.

Now it is used in co-operation and concurrentlywith other multiple access techniques.

d(t)

c(t)

s(t)

Figure 7: Spread spectrum modulator.

Delay

Demod.

c(t)

r(t) ∫Ts

0(·)dt

sn

Figure 8: Spread spectrum demodulator, r(t) = s(t − td ) +w(t), where w(t) is AWGN and interference.


Enabling technologies for XG evolution Spread spectrum

Spread spectrum II

α1 · s (t − t1)

α2 · s (t − t2)

α3 · s (t − t3)

Figure 9: Multipath in a wireless channel (source [5]).

0 500 1000 1500 2000 2500

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

τ

Cro

ssco

rrel

atio

n

Figure 10: Crosscorrelation of received signal with spread-ing sequence.

Spread spectrum helps in counteracting multipath effects, like frequency-selective fading.

◮ It makes an ally of an undesirable effect.

CDMA enables fully random access and asynchronous networks.

◮ It is though a system inherently limited by interference.


Enabling technologies for XG evolution Adaptive techniques

Adaptive techniques I

Figure 11: ACM and coverage capabilities (source [6]).

ACM (or AMC), Adaptive Coding &Modulation.

System dinamically adapts the channelcoding scheme and modulation spec-tral efficiency, given comm conditions.

Target: keep BER below a certain thresh-old, while maximizing data rate.

Algorithms are based on on-the-fly SNRmeasurements.

Figure 12: ACM and channel conditions (source [7]).


Enabling technologies for XG evolution Adaptive techniques

Adaptive techniques II

Figure 13: Improvements in arquitecture (source [8]).

Evolved architectures combine:ACM (PHY).

Incremental redundancy and fast retrans-missions (PHY).

Scheduling improvements in MAC sub-layer.

Adaptive techniques are scaling up to full and complex coordinated protocols, creating newarchitectures in PHY and MAC.

Examples in UMTS:

◮ HSDPA (High-Speed Downlink Packet Access).◮ HSUPA (for uplink).◮ HSPA+ (including OFDM, MIMO, allIP architecture).


Enabling technologies for XG evolution OFDM

OFDM I

S��+

subcarrier

mapping

P/S DACIDFT

modulated

symbols

OFDM

symbols

I channel

Q channel

output

frame

-

cos (2πfc t)

sin (2πfc t)Σv(t)

X0X1

X2

XN−1

v0

v1

v2

vN−1

Figure 14: OFDM transceiver.

−15 −10 −5 0 5 10 1510

−3

10−2

10−1

100

101

Normalized frequency

Pow

er s

pect

ral d

ensi

ty

Figure 15: OFDM spectrum.

OFDM (Orthogonal Frequency DivisionMultiplexing) decouples a wideband spec-trum into a set of discrete narrowband sub-carriers.

Core operations are FFT (Fast Fourier

Transform) based.◮ Algorithms and HW are highly efficient and op-

timized to build TX and RX.


Enabling technologies for XG evolution OFDM

OFDM II

PSD PSDchannel input

channel

channel output

replacements

fff

|Hc (f )|2

Figure 16: OFDM frequency decoupling against linear (amplitude) distortion.

time

frequency

subcarr

iers

modulated symbols

PilotsT

1T

Figure 17: OFDM resource mapping.

Subcarrier decoupling allows better spec-

trum management:◮ Channel undesirable effects are more easily coun-

teracted.◮ OFDM frame allows flexible resources manage-

ment.◮ It enables the possibility of handling together dis-

joint bands (carrier aggregation).◮ OFDM accomodates itself very well to other en-

abling technologies (e.g. ACM, MIMO).

Subcarrier packing is evolving fast to meet growing demand under more refined concepts [9]


http://webdemo.inue.uni-stuttgart.de/webdemos/08_research/waveform5G/index.php?id=0

Enabling technologies for XG evolution MIMO

MIMO I

Figure 18: MIMO wireless medium disentangling (source:[10]).

A MIMO system introduces and han-

dles interferences in the medium.◮ Interference as an ally.

Adequately managing TX and RX sig-nals to render the scheme useful re-quires refined and burdensome alge-braic methods.

Operations are easier if channel is nar-rowband decoupled (OFDM).

MIMO (Multiple Input-Multiple Output)concept characterizes multi-antenna TX(NT ) and/or RX (NR ) systems.

Figure 19: MIMO setup and channel model (source: [11]).


Enabling technologies for XG evolution MIMO

MIMO II

Figure 20: Spatial multiplexing concept (source: [12]).

By using pre-coding and de-coding, we can multiplex up tomin (NT , NR) parallel streams.

System rate is thus boosted.

Cost: high complexity, BERquality tradeoff.

The other flavor emphazisesdiversity exploitation for BERimprovement.

Maximal diversity gain up toNT × NR .

Figure 21: Diversity exploitation though space-time coding (source: [12]).

Diversity/multiplexing are excluding strategies


Enabling technologies for XG evolution Cognitive Radio

Finding and filling in the gaps I

Figure 22: Locating & managing white spaces in spectrum (source: [13]).

The idea is to take advantage of the time when a given band, though licensed, is not

effectively occupied by a communication.

◮ This raises the concepts of primary user, and secondary (opportunistic) user.


Enabling technologies for XG evolution Cognitive Radio

Finding and filling in the gaps II

Figure 23: SDR equipment schematics (source: [14]).

Figure 24: Cognitive radio functional blocks (source:[15]).

Cognitive radio requires:

◮ Spectrum sensing.◮ Flexible and reconfigurable

frontends.

Key enabler: SDR (software de-fined radio).

Cognitive radio poses challenges to effectively coordinate primary and secondaryusers/networks


http://www.websdr.org/

http://arstechnica.com/tech-policy/2012/07/how-software-defined-radio-could-revolutionize-wireless/

Enabling technologies for XG evolution Opening up new bands: an expanding frontier

Exploiting millimeter wave propagation I

Figure 25: US RF Spectrum allocation. 30 MHz-3 GHz bands are crowded with mobile, fixed and broadcast services(source: [16]).



Exploiting millimeter wave propagation II

Figure 26: Spectrum & bandwidth availability at the 60 GHZ band (source: [17]).



Exploiting millimeter wave propagation III

Figure 27: mmWave 5G setup (source: [18]).

60 GHz links are sensitive to obstacles and walls (non-penetrating waves).

mmWave may be thus used in indoor (small cells) and broadband PtP LOS links.

mmWave may be a good alternative to OF (Optical Fiber) expensive backhaul deployments.

The quest for spectrum beyond 3 GHz from the mobile comms industry poses possibleconflicts with services already being carried on related bands (e.g. satellite C-band).


http://www.intelsat.com/tools-resources/c-band/

Enabling technologies for XG evolution Massive MIMO

Massive MIMO I

Figure 28: MIMO scaling architecture (source: [19]).

The scale of the massive MIMO testbedsdesigned so far enables its usage for cen-tralized, macro cell base stations.

User terminals of appropriate size are notfit for massive MIMO (even low scaleMIMO itself), for usual wavelengths ofaround several cm.

At higher frequencies (smaller wave-lengths), it is possible to create bulkMIMO systems.

They enable the usage of smart an-tenna techniques: directional TX/RXto multiplex comms, diversity exploita-tion, and so on.

Figure 29: Massive MIMO testbed example (source: [20]).


Enabling technologies for XG evolution Massive MIMO

Massive MIMO II

Figure 30: IC with 2 mmWave antennas incorporated (source: [17]).

The exploitation of the 60 GHz (mm wavelength) spectrum opens the door to miniaturiza-tion and the possibility to include massive MIMO on user terminals.


Enabling technologies for XG evolution Small cells

Network improvements: scaling up & down I

Figure 31: Small cells HetNets setup, planned (source:[21]).

Figure 32: Small cells HetNets setup, unplanned, ad-hoc(source: [21]).

HetNets, a mesh of (somehow coordinated) heterogeneous networks, is the gamble for

boosting capacity, under two principles:◮ Simplification of the layer structure and protocols: flat architecture, allIP.◮ Creation and management of flexible high capacity small cells (pico-, femto-cells), that have to be fitted (con-

nected, coordinated) to backhaul and backbone network sections.


Enabling technologies for XG evolution Small cells

Network improvements: scaling up & down II

Figure 33: Small cells HetNets approach target capacity(source: [21]).

Reaching up to 1000× throughput in the

network requires:

◮ Putting together state-of-the-art en-abling technologies: OFDM, (mas-sive) MIMO, ACM, mmWave...

◮ Improvements in chipsets and RFsubsystems: fast switching to/fromLTE, WiFi, UMTS, WiMax...

◮ New deployment methods, able tocoordinate a loose hyerarchical meshof networks of different scales, anddifferent technologies (from OF ca-bles to LTE).

NGN (Next Generation Networking): bodyof network improvements aimed at guar-anteeing ubiquity, services independent ofthe underlying transport network(s).

Challenge: global roaming and seamless experience!


Enabling technologies for XG evolution LiFi

Solving the last few meters: LiFi I

Figure 34: Example of LiFi TX/RX setup (source: [22]).

In the visible spectrum, there are tons of spectrum for (ultra-)wideband transmission.

◮ Similar to OF usage, but employing non-guided wireless (visible) waves.

It is specially appealing to provide short range access to user terminals in indoor environ-ments (solves such bottlenecks).


Enabling technologies for XG evolution LiFi

Solving the last few meters: LiFi II

An enabling technology for small cells deployment.

In corporate environments, it can serve the explosive data rate demand for user access by

smartly managing the lighting installations.◮ It can handle indoor mobility minimizing collisions.◮ It naturally solves the interference issues from other wireless setups (WiFi), and eases the problem of an already

crowded spectrum (around the wall penetrating frequencies).

Figure 35: LiFi indoor mobility (source: [23]).


Enabling technologies for XG evolution Concluding remarks

Concluding remarks


Current and future MC cellular standards

Current and future MC cellular

standards


Current and future MC cellular standards What is a standard about?

What is a standard about?


https://courses.edx.org/courses/NotreDameX/EG240x/2T2015/courseware/4553a35b97744082bdc8d1ba553be2f4/7d4f3d4d22c747f8a8edf21cfd298b53/

Current and future MC cellular standards A non-stop evolution

A throughput race I

Figure 36: XG timeline (source: [24]).



A throughput race II

Figure 37: 1G-4G evolution main facts (source: [25]).



A throughput race III

XG Technology Peak rate Standard, access Timeline Features1G Analog 14.4 kbps AMPS, NMT, TACS 1970-1990 Voice only2G Digital narrowband

circuit data14.4 kpbs GSM (TDMA), IS-95

(CDMA)1990-2000 Voice & data by multiplexing over

single channels2.5G Packet data 171.2 kbps GPRS, EDGE 2001-2004 Mobile internet access popularizes,

phones start supporting web brows-ing

3G Packet data, broad-band

3.1 Mbps UMTS, CDMA2000 2000-2006 Multimedia services, universal ac-cess and portability, beyond phones

3.5G Packet data, broad-band

14.4 Mbps HSPA(+) 2006-2010 Higher throughput to meet growingdemand (explosive)

4G Packet data, broad-band, allIP

300 Mbps WiMax, LTE, WiFi 2010-2015 Higher throughput and portability,HD capabilities

5G Not yet defined X Gbps Not yet defined 2015-2020 1000× capacity and improvementsin roaming, seamless delivery andother features

Table 1: XG coarse characterization [26].


Current and future MC cellular standards 2G: from voice to data

2G: story of a success I

Figure 38: GSM architecture (source: [27]).


Current and future MC cellular standards 2G: from voice to data

2G: story of a success II

f ��

Amplitude

frame period frame period

slot duration

#� #�

t ��

PSD

B

modulated

symbols

Figure 39: TDMA frame.

By managing the TDMA frame,voice only GSM has expanded tooffer narrowband data:

◮ GPRS: General Packet Radio Ser-vice.

◮ EDGE: Enhanced Data Rates forGSM Evolution.

They involve also protocol andarchitecture improvements.

They could be applied with min-imum HW adjustments.

Challenges: to go further on data rates and service offering, we have to get rid of theTDMA frame on the medium access along with the burdensome and ad-hoc network

architecture, because they lack flexibility & scalability


Current and future MC cellular standards 3G: towards broadband access

3G: a first step forward I

Figure 40: UMTS architecture: note the similarities with GSM one (source: [28]).



3G: a first step forward II

Without fully re-managing the GSM net-

work, UMTS may offer more than 10×

rates.

◮ The improvements lie mainly on themedium access part.

◮ UMTS strongly relies on CDMA,cornerstone of UTRAN (UniversalTerrestrial Radio Access Network)interface.

◮ Voice is largely managed as in GSM.◮ Cost: spectrum allocation.

Portability expands: access for any kind ofdevice, not just phones.

From phones... to smartphones.

Figure 41: UMTS usage statistics, Spain and EU-27(source [29]).

Challenges: higher rates, higher flexibility and better evolution chances requiregetting rid of 2G legacy network architecture, and go well beyond improvements in

medium access techniques



3G: a first step forward III

Figure 42: HSPA+ deployments (source: [30]).

HSPA+ offers an expanding alternative for further evolution, adding higher-order modula-tions, sophisticated ACM, MIMO, allIP capabilities.


Current and future MC cellular standards 4G: first rival to fixed networks

4G: long term evolution? I

Figure 43: LTE (Long Term Evolution) network architecture, user plane (source: [31]).

The allIP architecture encompasses a big leap forward: a whole change of paradigm.


Current and future MC cellular standards 4G: first rival to fixed networks

4G: long term evolution? II

Figure 44: LTE roadmap (source: [32]).

LTE-4G makes an effort to stitch to-

gether many of the enabling technolo-

gies seen.◮ OFDM, carrier aggregation, MIMO...

3GPP 4G definition states 1 Gbps peakrate for low to no mobility.

4G access becomes thus a competi-tive alternative for broadband access,or backhaul networking.

Removing the need to resort to legacyvoice fallback mobile networks requireenabling voice over LTE (VoLTE/IP).

VoLTE, along with GSM/UMTS dis-continuation, would free vital spec-trum resources.

Challenges: making effective VoLTE, ubiquity, seamless experience, lower latency,UMTS evolved networks compete with LTE as 4G alternative, while 5G is already

on-the-go


Current and future MC cellular standards 5G: pushing further the challenge

5G: everywhere, everybody, everything I

Figure 45: 5G new paradigm (source: [25]).

NGMN Alliance (Next Generation MobileNetworks Alliance) requires for 5G:

◮ Data rates of tens of Mbps should be sup-ported for tens of thousands of users.

◮ 1 Gbps to be offered, simultaneously totens of workers on the same office floor(cloud computing requirements).

◮ Several hundreds of thousands of simul-taneous connections supported for mas-sive sensor deployments (IoT -Internet ofThings- requirements).

◮ Spectral efficiency, compared to 4G, hasto be significantly enhanced.

◮ Coverage should be improved (ubiquity).◮ Signalling efficiency enhanced (lower la-

tency).


Current and future MC cellular standards 5G: pushing further the challenge

5G: everywhere, everybody, everything II

mmW

MIMO i

adioWireless

n��

v �� ion

Small cells

HetNets

Interference

& mobility

management

ed

standards

Figure 46: 5G enabling technologies.

5G target performance requiresputting together advanced im-provements over all possible lay-ers (PHY, MAC, network).

New paradigm:◮ Pervasive.◮ User-centric.◮ Flexible.◮ Ad-hoc.◮ Reconfigurable.◮ Capabilities for M2M (machine-to-

machine) communications.

Challenges: making sense out of this “chaos”, controlling latency, efficientinterconnection & cooperation with cable/fiber backbone networks, beware of

densification [33]


Current and future MC cellular standards From the last mile to the last centimeters

Bridging along I

The IEEE brands WiMAX (IEEE 802.16, [34]) and WiFi (IEEE 802.11,[35]) contribute to complete the ecosystem.

Native 5G connections may pro-vide backhauling with high mobil-ity.

WiMAX and WiFi may bridge theneeds from the last mile downto the short-range home environ-ment, under more static condi-tions.

They may integrate in the HetNet,allIP 5G connectivity pool.

Figure 47: Rate vs mobility snapshot before 5G (source [36]).


Current and future MC cellular standards From the last mile to the last centimeters

Quite a mesh I

IEEE brand ZigBee (IEEE 802.14-5 [37]) and Bluetooth [38] come along to provide theshortest-range mobile mesh connection capabilities required by the IoT and M2M.

Figure 48: ZigBee module (source: [39]). Figure 49: Bluetooth module (source: [40]).

All this comes together with the possibilities opened by RFID technology!


Current and future MC cellular standards Concluding remarks

Concluding remarks


Situation of XG worldwide

Situation of XG worldwide


Situation of XG worldwide GSMA worldwide report

GSMA worldwide report [41] I



GSMA worldwide report [41] II



GSMA worldwide report [41] III


Situation of XG worldwide Spectrum dividend

Spectrum Dividend I

Figure 50: Situation of spectrum dividend for 800 MHz or 700 MHz bands, depending on countries (source: [42])a.

aDDS has been licesend to MNOs according to the regionally harmonised band plan. DDS has been licensed allocated for mobile - band plan yetTBA. DD regionally harmonised band plan has been announced - not yet licensed to MNOs. DD has been identified for mobile and US band planlicensed/committed for mobile service. DDS has not been allocated for mobile. No information available.



Spectrum Dividend II

Figure 51: Spectrum dividend in Spain (source: [43]).


http://www.televisiondigital.gob.es/DividendoDigital/Paginas/dividendo-digital.aspx


Spectrum Dividend III

Figure 52: New bands quest (source: [41]).


Situation of XG worldwide Deployments

Deployments I

Figure 53: Mobile internet broadband subscriptions in 2012, as a percentage of the country’s population (source: [44]).


Situation of XG worldwide Deployments

Deployments II

Figure 54: LTE deployments as of December 2014. Red: countries and regions with commercial LTE service. Blue: countriesand regions with commercial LTE network deployment on-going or planned. Grey: countries and regions with LTE trial systems(pre-commitment) (source: [45]).


Situation of XG worldwide GSMA North America report

GSMA North America report [41] I


Situation of XG worldwide GSMA Latin America report

GSMA Latin America report [41] I


Situation of XG worldwide GSMA Latin America report

GSMA Latin America report [41] II


Situation of XG worldwide GSMA Asia-Pacific report

GSMA Asia-Pacific report [41] I



GSMA Asia-Pacific report [41] II



GSMA Asia-Pacific report [41] III


Situation of XG worldwide GSMA Europe report

GSMA Europe report [41] I


Situation of XG worldwide GSMA Arab States report

GSMA Arab States report [41] I


Situation of XG worldwide GSMA Subsaharian Africa report

GSMA Subsaharian Africa report [41] I


Situation of XG worldwide Concluding remarks

Concluding remarks


Business & opportunities

Business & opportunities


Business & opportunities M2M, IoT

M2M, IoT I

Figure 55: Example of IoT strategy for a mobile consortium (source: [46]).

Many of the developments to come will be related to the M2M and IoT concepts.


https://www.youtube.com/watch?v=aJLM1mmgS8g

Business & opportunities Healthcare opportunities

Healthcare opportunities I

Figure 56: mHealth programs overview (source: [42]).

Pressure on healthcare systems pushes towards a more efficient use of resources.

Mobile communications can help by sharing and exploiting information at various

levels.

◮ Avoid unneded journeys, reduce delays in consultations...

Connectivity is not the only factor: availability of smart terminals & applicationsis key for exploitation of mHealth possibilities.

mHealth programs can be of capital interest in rural and undeveloped areas.


Business & opportunities Digital commerce

Digital commerce I

Figure 57: Digital commerce in retail example (source: [47]).

Payment management in commerce(online or in-store) is to benefit greatlyfrom ubiquity and mobility.

Technology advances enables bettermanagement and lower costs.


Business & opportunities Social networking opportunities

Social networking opportunities I

Figure 58: Waze app screenshot (source: [48]).

An example: the Waze app forsmartphones with geolocation capa-bilities.

◮ As other navigators, provides turn-by-turn information.

◮ Unlike other navigation SW, providesuser-submitted travel times and routedetails.

◮ Waze is community-driven, as opposedto commercial navigation SW encom-passing on-the-fly traffic information.

◮ The app is monetized through location-based advertising.


https://www.waze.com/

Business & opportunities Automotive opportunities

Automotive opportunities I

Figure 59: mAutomotive concepts (source: [49]).

Combination of satellite-based navigation and M2M capabilities in smart devicesmay allow cheaper and safer automotive experiences.


Business & opportunities Educational opportunities

Educational opportunities I

Figure 60: mEducation Philipines case study (source: [50]).

Many Philipinos have access to mobiletechnologies on a daily basis.

6M are OSYs (out-of-school youths)with hampered possibilities of employ-ment.

1M have accessed a PPP (public-private partnership) platform providingeducational resources.


Business & opportunities Banking the underbanked

Banking the underbanked I

Figure 61: Number of live mobile money services by region (source:[41]).

Lack of financial services availabilitymay hamper development in manyparts of the world, specially in ruralareas.

Mobile technology may help deliver fi-

nancial inclusion across the world.◮ MC: connection, mobility and identifica-

tion.

Mobile money services are now avail-

able in over 60% of the world’s devel-oping markets.

Providers are building a broader pay-ments ecosystem.

Mobile money users transacted a totalof US$16.3 billion through 717.2 mil-lion transactions (Dec 2014).


http://www.millicom.com/who-we-are/our-brands/tigo-money/

Business & opportunities Opportunities for development

Opportunities for development I

Figure 62: Outcome of an experience of agricultural information service in India (source: [51]).

Mobile communications offer huge possibilities to enhance living in developing areas by

◮ Enabling cooperation, information sharing, location, emergency response and man-agement...


Business & opportunities Concluding remarks

Concluding remarks


Final remarks

Final remarks


References

References


References

Bibliography I

[1] [Online]. Available: http://wearesocial.net/blog/2014/09/world-mobile-phone

[2] [Online]. Available: https://twitter.com/benoitaimond/status/583262867387998208

[3] [Online]. Available: http://iot.sys-con.com

[4] [Online]. Available: http://www.internet-of-things-research.eu

[5] [Online]. Available: http://www.slideshare.net/FranJEscribano/mat-block4

[6] [Online]. Available: http://www.conniq.com/InternetAccess WiMAX-04.htm

[7] [Online]. Available: http://www.comtechefdata.com/technologies/acm

[8] [Online]. Available: http://www.mobilecomms-technology.com/projects/hsdpa

[9] [Online]. Available: http://www.hindawi.com/journals/aee/2014/482805

[10] [Online]. Available: http://wcsp.eng.usf.edu/research.html

[11] [Online]. Available: http://www.gaussianwaves.com/2014/08/characterizing-a-mimo-channel

[12] [Online]. Available: http://users.ece.utexas.edu/∼jandrews/molabview.html

[13] [Online]. Available: http://www.eedailynews.com/2011/06/mindspeed-5g-networks-will-be-enabled.html

[14] [Online]. Available: http://www.ettus.com

[15] [Online]. Available: https://www.altera.co.jp/solutions/technology.html

[16] [Online]. Available: http://www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf


http://wearesocial.net/blog/2014/09/world-mobile-phone

https://twitter.com/benoitaimond/status/583262867387998208

http://iot.sys-con.com

http://www.internet-of-things-research.eu

http://www.slideshare.net/FranJEscribano/mat-block4

http://www.conniq.com/InternetAccess_WiMAX-04.htm

http://www.comtechefdata.com/technologies/acm

http://www.mobilecomms-technology.com/projects/hsdpa

http://www.hindawi.com/journals/aee/2014/482805

http://wcsp.eng.usf.edu/research.html

http://www.gaussianwaves.com/2014/08/characterizing-a-mimo-channel

http://users.ece.utexas.edu/~jandrews/molabview.html

http://www.eedailynews.com/2011/06/mindspeed-5g-networks-will-be-enabled.html

http://www.ettus.com

https://www.altera.co.jp/solutions/technology.html

http://www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf

References

Bibliography II

[17] [Online]. Available: http://nyuwireless.com/NYSWAX.pdf

[18] [Online]. Available: http://www.slideshare.net/ctrutaustin/heath-45522468

[19] [Online]. Available: http://itrl.chonnam.ac.kr/∼itrlhome s2/xe/?mid=research 11

[20] [Online]. Available: http://www.ni.com/white-paper/52382/en

[21] [Online]. Available: https://www.qualcomm.com/invention/technologies/1000x/small-cells

[22] [Online]. Available: http://micro.org/bldsomething

[23] [Online]. Available: http://purelifi.com/li-fire/how-purelifi-li-fire-works

[24] [Online]. Available: http://www.futuretimeline.net/blog/2015/01/22.htm#.VTpwG3WlAUQ

[25] [Online]. Available: http://europa.eu/rapid/press-release MEMO-14-129 en.htm

[26] [Online]. Available: http://www.bmedia4tech.com

[27] [Online]. Available: http://en.wikipedia.org/wiki/GSM

[28] [Online]. Available: http://en.wikipedia.org/wiki/Universal Mobile Telecommunications System

[29] [Online]. Available: http://www.ontsi.red.es/ontsi/en/indicador/individuals-using-mobile-phone-umts-3g-access- internet

[30] [Online]. Available: http://www.gsma.com

[31] [Online]. Available: http://www.mastertelecomfaster.com/index.php

[32] [Online]. Available: http://www.4gamericas.org


http://nyuwireless.com/NYSWAX.pdf

http://www.slideshare.net/ctrutaustin/heath-45522468

http://itrl.chonnam.ac.kr/~itrlhome_s2/xe/?mid=research_11

http://www.ni.com/white-paper/52382/en

https://www.qualcomm.com/invention/technologies/1000x/small-cells

http://micro.org/bldsomething

http://purelifi.com/li-fire/how-purelifi-li-fire-works

http://www.futuretimeline.net/blog/2015/01/22.htm#.VTpwG3WlAUQ

http://europa.eu/rapid/press-release_MEMO-14-129_en.htm

http://www.bmedia4tech.com

http://en.wikipedia.org/wiki/GSM

http://en.wikipedia.org/wiki/Universal_Mobile_Telecommunications_System

http://www.ontsi.red.es/ontsi/en/indicador/individuals-using-mobile-phone-umts-3g-access-internet

http://www.ontsi.red.es/ontsi/en/indicador/individuals-using-mobile-phone-umts-3g-access-internet

http://www.gsma.com

http://www.mastertelecomfaster.com/index.php

http://www.4gamericas.org

References

Bibliography III

[33] [Online]. Available: http://www.comsoc.org/ctn/will-densification-be-death-5g

[34] [Online]. Available: http://www.wimaxforum.org/index.htm

[35] [Online]. Available: http://www.wi-fi.org

[36] [Online]. Available: https://en.wikipedia.org/wiki/WiMAX

[37] [Online]. Available: http://www.zigbee.org

[38] [Online]. Available: http://www.bluetooth.com/Pages/Bluetooth-Home.aspx

[39] [Online]. Available: https://en.wikipedia.org/wiki/ZigBee

[40] [Online]. Available: https://en.wikipedia.org/wiki/Bluetooth

[41] [Online]. Available: http://www.gsma.com/me-reports

[42] [Online]. Available: http://mph.gsma.com/publicpolicy/handbook/business-environment

[43] [Online]. Available: http://www.televisiondigital.gob.es/DividendoDigital/Paginas/dividendo-digital.aspx

[44] [Online]. Available: http://en.wikipedia.org/wiki/Mobile broadband

[45] [Online]. Available: http://en.wikipedia.org/wiki/LTE (telecommunication)

[46] [Online]. Available: http://www.gsma.com/connectedliving/wp-content/uploads/2015/03/Etisalat.pdf

[47] [Online]. Available: http://www.gsma.com/digitalcommerce/digital-commerce-in-retail

[48] [Online]. Available: https://en.wikipedia.org/wiki/Waze


http://www.comsoc.org/ctn/will-densification-be-death-5g

http://www.wimaxforum.org/index.htm

http://www.wi-fi.org

https://en.wikipedia.org/wiki/WiMAX

http://www.zigbee.org

http://www.bluetooth.com/Pages/Bluetooth-Home.aspx

https://en.wikipedia.org/wiki/ZigBee

https://en.wikipedia.org/wiki/Bluetooth

http://www.gsma.com/me-reports

http://mph.gsma.com/publicpolicy/handbook/business-environment



http://en.wikipedia.org/wiki/Mobile_broadband

http://en.wikipedia.org/wiki/LTE_(telecommunication)

http://www.gsma.com/connectedliving/wp-content/uploads/2015/03/Etisalat.pdf

http://www.gsma.com/digitalcommerce/digital-commerce-in-retail

https://en.wikipedia.org/wiki/Waze

References

Bibliography IV

[49] [Online]. Available: http://www.gsma.com/connectedliving/automotive

[50] [Online]. Available: http://www.gsma.com/connectedliving/mobilelearning

[51] [Online]. Available: http://www.gsma.com/mobilefordevelopment/case-study-airtel-green-sim


http://www.gsma.com/connectedliving/automotive

http://www.gsma.com/connectedliving/mobilelearning

http://www.gsma.com/mobilefordevelopment/case-study-airtel-green-sim

an overview on current trends in mobile communications

Technology

mobile communications

escribano current trends

xg evolution francisco

crosscorrelation figure

spread spectrum demodulator

spread spectrum modulator

references francisco

overview francisco