3. Evolution to cellular networks –
communication anytime, anywhere
• Radio communication was invented by Nikola Tesla and Guglielmo Marconi: in
1893, Nikola Tesla made the first public demonstration of wireless (radio)
telegraphy; Guglielmo Marconi conducted long distance (over see) telegraphy
1897
• In 1940 the first walkie-talkie was used by the US military
• In 1947, John Bardeen and Walter Brattain from AT&T’s Bell Labs invented the
transistor (semiconductor device used to amplify and switch electronic signals)
• AT&T introduced commercial radio comm.: car phone – two way radio link to
the local phone network
• In 1979 the first commercial cellular phone service was launched by the Nordic
Mobile Telephone (in Finland, Sweden, Norway, Denmark).
4. Cellular Network Basics
• There are many types of cellular services; before delving into details, focus on basics (helps
navigate the “acronym soup”)
• Cellular network/telephony is a radio-based technology; radio waves are electromagnetic
waves that antennas propagate
• Most signals are in the 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz frequency bands
Cell phones operate in this frequency
range (note the logarithmic scale)
5. Cellular Network
• Base stations transmit to and receive from mobiles at the assigned
spectrum
• Multiple base stations use the same spectrum (spectral reuse)
• The service area of each base station is called a cell
• Each mobile terminal is typically served by the ‘closest’ base stations
• Handoff when terminals move
6. NetworkCells
• the entire network coverage area is divided into cells based on the
principle of frequency reuse
• a cell = basic geographical unit of a cellular network; is the area around an
antenna where a specific frequency range is used; is represented
graphically as a hexagonal shape, but in reality it is irregular in shape
• when a subscriber moves to another cell, the antenna of the new cell
takes over the signal transmission
• a cluster is a group of adiacent cells, usually 7 cells; no frequency reuse is
done within a cluster
• the frequency spectrum is divided into subbands and each subband is
used within one cell of the cluster
• in heavy traffic zones cells are smaller, while in isolated zones cells are
larger
7. Frequencyreuse
• is a method used by service providers to improve the
efficiency of a cellular network and to serve millions
of subscribers using a limited radio spectrum
• is based on the fact that after a distance a radio wave
gets attenuated and the signal falls bellow a point
where it can no longer be used or cause any
interference
• a transmitter transmitting in a specific frequency
range will have only a limited coverage area
• beyond this coverage area, that frequency can be
reused by another transmitter
Neighboring cells operate on different
frequencies to avoid interference
8. The Multiple Access Problem
• The base stations need to serve many mobile
terminals at the same time (both downlink and
uplink)
• All mobiles in the cell need to transmit to the base
station
• Interference among different senders and receivers
• So we need multiple access scheme
10. Frequency Division Multiple
Access
• Each mobile is assigned a separate frequency channel for the duration of the call
• Sufficient guard band is required to prevent adjacent channel interference
• Usually, mobile terminals will have one downlink frequency band and one uplink
frequency band
• Different cellular network protocols use different frequencies
• Frequency is a precious and scare resource. We are running out of it
• Cognitive radio
frequency
11. Time Division Multiple Access
• Time is divided into slots and only one mobile terminal transmits
during each slot
• Like during the lecture, only one can talk, but others may take the floor in turn
• Each user is given a specific slot. No competition in cellular
network
• Unlike Carrier Sensing Multiple Access (CSMA) in WiFi
Guard time – signal transmitted by mobile
terminals at different locations do no arrive
at the base station at the same time
12. Code Division Multiple Access
• Use of orthogonal codes to separate different transmissions
• Each symbol of bit is transmitted as a larger number of bits using the user
specific code – Spreading
• Bandwidth occupied by the signal is much larger than the information transmission rate
• But all users use the same frequency band together
Orthogonal among users
13. Themobileexperienceis expanding
everywhere
2
1 Source:GSMA Intelligence, Apr. ‘14; 2 Source:MachinaResearch, ‘13;3 Source:Gartner, Sep. ‘13
Billionsof MobileConnections BillionsofMobileExperiences
“”
~7Billion
Mobile connections,
almost as many as
people on Earth1
~25Billion
Interconnected devices
forecast in 20202
>100Billion
App downloads
completed in 20133
~270Billion
App downloads
expected in 20173
14. 3
Mobile is anamazingtechnical
achievement
Mind-blowingPerformance
with processing powergreater
than the most advanced super computers
of the early1990s1
Jaw-droppingGraphics
with capability to processseveral
thousand megapixels per second2
ReliableConnectivity
overcoming signal loss resulting in
receiving signal 100 trillion times weaker
than when it originated3
BroadbandSpeeds
with blazing fast data ratescapable
of 300+ Mbps4
All inadevice
that fits in
yourpocket
1 Source: Charlie White,Sep.'13 &giffgaff.com,Sep’13; 2 Basedonlatest Qualcomm®SnapdragonTM 800 seriesprocessors;3 Basedon>140dBpath loss typical in mobile;
4 Basedonpeakdatarates for LTEAdvanced;5Basedon>2,000mAhsmartphone battery and>60W light-bulb
LongBatteryLife
with ability to power allthese amazing
experiences with less energy than it takes
to power a light bulb for 15minutes5
HighQualityMultimedia2
4K UltraHD video player/recorder
HD gamingconsole
5.1/7.1surround sound system
High resolution digitalcamera
15. 4
Connectivity is the foundation of a
great mobileexperience
Deliveringrichmobilebroadbandexperiences
ConnectReliably
Talk and browse without interruption
with more bars in moreplacesConnectReal-Time
Get instant access to content with
less delay for “always-on” experience
ConnectFast
Stream, surf, upload, and download
with fast, predictable data rates
ConnectOn-the-Go
Talk and browse with seamless
mobility anywhere you get asignal
ConnectLonger
Go longer without plugging in
with improved battery efficiency
16. Cellular Network Generations
• It is useful to think of cellular Network/telephony in
terms of generations:
• 0G: Briefcase-size mobile radio telephones
• 1G: Analog cellular telephony
• 2G: Digital cellular telephony
• 3G: High-speed digital cellular telephony (including
video telephony)
• 4G: IP-based “anytime, anywhere” voice, data, and
multimedia telephony at faster data rates than 3G
18. • Mobile radio telephones were used for military communications in
early 20th century
• Car-based telephones first introduced in mid 1940s
• Single large transmitter on top of a tall building
• Single channel used for sending and receiving
• To talk, user pushed a button, enabled transmission and disabled
reception
• Became known as “push-to-talk” in 1950s
• CB-radio, taxis, police cars use this technology
• IMTS (Improved Mobile Telephone System) introduced in 1960s
• Used two channels (one for sending, one for receiving)
• No need for push-to-talk
• Used 23 channels from 150 MHz to 450 MHz
0G Wireless
19. 5
Poweredbyevolvingmobiletechnologiesforbetter
experiences
N/A <0.5Mbps1 63+Mbps2 300+Mbps3
AnalogVoice DigitalVoice+ SimpleData MobileBroadband FasterandBetter
Mobile2G
D-AMPS, GSM/GPRS,
cdmaOne
Mobile3G
CDMA2000/EV-DO,
WCDMA/HSPA+, TD-SCDMA
Mobile4GLTE
LTE, LTE Advanced
Mobile1G
AMPS, NMT, TACS
Richer Content
(Video)
More
Connections
1Peakdatarate for GSM/GPRS,latest EvolvedEDGEhaspeakDLdataratescapable of up to 1.2Mbps; 2Peakdatarate for HSPA+DL3-carrier CA;HSPA+specification includesadditional potentialCA+ useof multiple antennas,but noannouncementsto
date; 3 Peakdatarate for LTEAdvancedCat 6 with 20+ 20 MHzDLCA;LTEspecification includesadditional potentialCA+ additional useof multiple antennas,but noannouncementsto date
20. 7
Cleared spectrum for exclusiveuse
by mobiletechnologies
Reusing frequencies without interference
through geographical separation
Operator-deployed basestations
provide access for subscribers
Neighboring cellsoperate on different
frequencies to avoid interference
Integrated, transparent backhaul
networkprovides seamlessaccess
Coordinated network for seamless
access and seamlessmobility
3
MobileNetwork
2
FrequencyReuse
1
LicensedSpectrum
PSTN
(landline)
Mobile1Gestablishedthe foundationofmobile
22. 9
A B
FrequencyDivisionMultiple Access(FDMA)*
Large frequency gap required between users to avoidinterference
* Exampleshown based onAMPS1G technology
Support for only 1user (analog phone call) per channel
30
kHz
30
kHz
30
kHz
30
kHz
30
kHz
30
kHz
A
30
kHz
B
30
kHz
LimitedCapacity
Analog transmissions are inefficient at
using limited spectrum
LimitedScalability
Analog devices are large/heavy, power
inefficient, and high cost
1G analogvoice wasamazing,but limited
23. 10
1980s 1990s
Mobile for the Masses
MoreVoiceCapacity
Mobile2G
D-AMPS, GSM/GPRS,
cdmaOne
Mobile1G
AMPS, NMT, TACS
Foundation of Mobile
SeamlessMobility
1010110100111000
Mobile 2G digital technologies
increasedvoicecapacity
Deliveringmobilevoiceservicesto themasses– morepeople,inmoreplaces
24. GSM
• Abbreviation for Global System for Mobile
Communications
• Concurrent development in USA and Europe in the
1980’s
• The European system was called GSM and deployed
in the early 1990’s
25. GSM Services
• Voice, 3.1 kHz
• Short Message Service (SMS)
• 1985 GSM standard that allows messages of at most 160 chars.
(incl. spaces) to be sent between handsets and other stations
• Over 2.4 billion people use it; multi-billion $ industry
• General Packet Radio Service (GPRS)
• GSM upgrade that provides IP-based packet data transmission up to
114 kbps
• Users can “simultaneously” make calls and send data
• GPRS provides “always on” Internet access and the Multimedia
Messaging Service (MMS) whereby users can send rich text, audio,
video messages to each other
• Performance degrades as number of users increase
• GPRS is an example of 2.5G telephony – 2G service similar to 3G
26. GSM Channels
• Physical Channel: Each timeslot on a carrier is referred to as a
physical channel
• Logical Channel: Variety of information is transmitted between
the MS and BTS. Different types of logical channels:
• Traffic channel
• Control Channel
Downlink
Uplink
Channels
27. GSM Frequencies
• Originally designed on 900MHz range, now also
available on 800MHz, 1800MHz and 1900 MHz
ranges.
• Separate Uplink and Downlink frequencies
• One example channel on the 1800 MHz frequency band,
where RF carriers are space every 200 MHz
1710 MHz 1880 MHz1805 MHz1785 MHz
UPLINK FREQUENCIES DOWNLINK FREQUENCIES
UPLINK AND DOWNLINK FREQUENCY SEPARATED BY 95MHZ
30. 12
Mobile2Gdigital wirelesstechnologiesenabledmoreusers
TimeDivisionMultiple Access(TDMA)
Allowsmultipleusersper radio channelwith eachusertalking oneat atime
VoiceEncoder
(Vocoder)
UncompressedVoiceSignal
64 kb persecond
CompressedVoiceSignal
8kb persecond
MoreVoiceCapacity
Digital transmissions enable compressed voice and
multiplexing multiple users per channel
Initial 2Gtechnologies (D-AMPS,GSM)basedonTDMA
ScalableTechnology
Digital components cost/weight far less plus deliver
more securesignal
(pocket-sized)>1userper radiochannel
A B C
Time30kHz
32. 15
Eachusers
information
codedwith
uniquecode
Frequency
CDMAutilizes all the available spectrum to
support moreusers
Ability to supportmany
moreusers(>10x1G)
withsamespectrum
Utilizeallavailable
spectrum
Norigid deliveryschedule–
deliverytruckcantake
advantageofwhenuserisnot
talkingto supportmorecallers
33. 16
CDMAenablesusersto sharethe samefrequency and
communicate at the same time
SpreadusingCodeA
SpreadusingCodeB
SpreadusingCodeC
UserA
UserB
UserA
+
UserB
+
UserC
UserC
CodeDivisionMultipleAccess(CDMA)
Multiple users can talk at same time using
different languages(“codes”)
At theTransmitter At theReceiver
Reconstructusing
CodeC
Reconstructusing
CodeB
Reconstructusing
CodeA
Other signals
look likenoise
1.25MHz
Voice Voice
Voice
Voice
Voice
Voice
Voice
Voice
Voice
Voice
Voice
Voice
Voice
Voice
34. CDMAdeliveredunprecedentedvoicecapacityandmuch more
CDMATimeline2
February1990
First CDMA field trial completedby
Qualcomm andNYNEX
March1992
Standards committee formed in
Telecommunications IndustryAssociation
May1995
IS-95 revision A (cdmaOne)released
December1995
First commercial deployment
December1999
cdmaOne subscribers pass 50 million
worldwide (>80 operators in >30countries)
CDMABenefits
Increased voice capacity by severaltimes
Provided more efficient use of spectrumresources
Increased battery life in mobiledevices
Better security with CDMAencoding
CDMAisthe foundationfor
Mobile3Gtechnologies
PotentialVoiceCapacityImprovements1
Reference
(1x)
~3x
~14x
Analog
1980s
GSM
1990s
cdmaOne
1990s
18
1 Approximatetotal numberof subscribersservicedwithin samespectrumbased onAMPS (1G),GSMandcdmaOnetechnology commercialdeployed in 1990s; 2 Source: CDG, www.cdg.org
36. 20
1980s 1990s 2000s
Mobile2G
D-AMPS, GSM/GPRS,
cdmaOne
Mobile for the Masses
MoreVoiceCapacity
Mobile3G
CDMA2000/EV-DO,
WCDMA/HSPA+, TD-SCDMA
Mobile Broadband
DataOptimizedMobile1G
AMPS, NMT, TACS
Foundation of Mobile
SeamlessMobility
1010110100111000
Mobile3Gevolvedmobilefordata
Introducing high-speedinternet accessfor the first time
38. 28
1980s 1990s 2010s2000s
Mobile Broadband
DataOptimized
Faster and Better Mobile Broadband
MoreDataCapacityMobile2G
D-AMPS, GSM/GPRS,
cdmaOne
Mobile for the Masses
MoreVoiceCapacity
Mobile3G
CDMA2000/EV-DO,
WCDMA/HSPA+, TD-SCDMA
LTE, LTE Advanced
Mobile1G
AMPS, NMT, TACS
Foundation of Mobile
SeamlessMobility
1010110100111000
Mobile4GLTEisevolvingto providemoredata capacity
Delivering faster andbetter mobilebroadband experiences
Mobile4GLTE
39. 4G (LTE)
• LTE stands for Long Term Evolution
• Next Generation mobile broadband technology
• Promises data transfer rates of 100 Mbps
• Based on UMTS 3G technology
• Optimized for All-IP traffic
42. 32
GlobalLTEnetwork launches
Largedeviceecosystem
279Launches
101Countries
1,563Devices
>100Vendors
Source: GSA, Mar. ‘14
Mobile4GLTEis the first global standard
for mobile broadband
LTEFDD<ETDD
Two modes, common standard, sameecosystem
Spectrum1
Spectrum2
Uplink(UL)
Downlink(DL)
FrequencyDivisionDuplex(FDD)
Paired spectrum enables
better coverage
Time
Spectrum
TimeDivisionDuplex(TDD)
Unpaired spectrum enables asymmetrical
DL/UL for more DLcapacity
Time
UL DL UL DL
45. Service Roadmap
Improved performance, decreasing cost of delivery
Typical
average bit
rates
(peak rates
higher)
WEB browsing
Corporate data access
Streaming audio/video
Voice & SMS Presence/location
xHTML browsing
Application downloading
E-mail
MMS picture / video
Multitasking
3G-specific services take
advantage of higher bandwidth
and/or real-time QoS
A number of mobile
services are bearer
independent in nature
HSDPA
1-10
Mbps
WCDMA
2
Mbps
EGPRS
473
kbps
GPRS
171
kbps
GSM
9.6
kbps
Push-to-talk
Broadband
in wide area
Video sharing
Video telephony
Real-time IP
multimedia and games
Multicasting
CDMA
2000-
EVDO
CDMA
2000-
EVDV
CDMA
20001x
47. 39
1Gestablished seamless mobile
connectivity introducing mobile
voiceservices
Evolvingmobiletechnologiesdelivergreatmobileexperiences
3
4
4GLTEdeliversmorecapacityfor
faster andbetter mobile
broadbandexperiences,andis also
expanding in to newfrontiers
2
1
2Gdigital wireless technologies
increasedvoice capacitydelivering
mobileto themasses
3Goptimized mobilefor data
enablingmobilebroadband
services,andis evolving for faster
andbetter connectivity
5
5Gnetworksystemhasmuch
higherspeedsandcapacity,and
muchlowerlatency,thanexisting
cellularsystems.
48. 5G – Wireless Technology
• 5G is a packet switched wireless system with wide
area coverage and high throughput.
• 5G wireless uses OFDM and millimeter wireless
that enables data rate of 20 Mbps and frequency
band of 2-8 GHz.
• 5G is going to be a packed based network.
49. About 5G
• Frequency bands are really high
• 28GHz, 37GHz, 39GHz, 42GHz, 60GHz.
• Typically called millimeter wave (1 – 10 millimeter).
• Advantage
• Can send and receive the data at very high speed with
huge payload.
• Disadvantages
• Shorter range
• With increase in frequencies the connection/signals
eventually drops.
• Due to weather conditions
50. 5G Technologies
• The size of antenna is too small in size.
• Approximate 1/4 of the wavelength.
• May use multiple antennas
• Like in pair of 2, 4, 8 pairs
• Can establish small towers
• Cell frequencies Reuse
• Directional Antennas
• For communication between the towers
NO standard has been set/defined for 5G technology
51. 5G Services
• 5G being developed to accommodate QoS rate
requirements set by further development of
existing 4G applications.
• Flexible channel bandwidth between 5 and 20MHz,
optionally up to 40MHz.
• Data rate of at least 1Gb/s between any two points
in the world.
52. Benefits of using 5G
• High speed, high capacity, and low cost per bit.
• Support interactive multimedia, voice, streaming video,
Internet, and other broadband services, more effective
and more attractive ,Bi directional, accurate traffic
statistics.
• Global access, service portability, and scalable mobile
services.
• The high quality services of 5G technology based on
Policy to avoid error.
• 5G technology is providing large broadcasting of data in
Gigabit which supporting almost 65,000 connections.
• Through remote management offered by 5G
technology a user can get better and fast solution.
53. Applications of 5G
Mobile Broadband Dense Crowd of users
IoT Sensor Network IoT Control Network
5G
Vey High
Data Rate
Very High
Capacity
Reliability,
Resilience,
security
Very Low
latency
Long
Battery
Lifetime
Massive
number of
devices
Mobility