Wireless Communication
Instructor: Dr. İlhan BAŞTÜRK
E-mail: ilhan.basturk@adu.edu.tr
Course Information
Instructor
Dr. İlhan BAŞTÜRK
 Schedule
Wednesdays 13:30-16:15 (MA204)
 Office Hours
Tuesdays 13:30 – 15:30

(Office: C-211, Faculty of Eng., Block C, 1st floor)
!!!!! No office hours in exam weeks.
Course Information

Source Book:
“Wireless Communications”, Theodore S. Rappaport, 2nd Ed.
Prentice Hall, 2002.
Supplementary Books:

“Wireless Communications”, Andrea Goldsmith, Cambridge
University Press, 2005

“Wireless Communications”, Andres F. Molish, Wiley – IEEE, 2010
Course Information
Grading


Project : 50%
Final : 50%
Grade
Letter
95 - 100
A1
90 - 94
A2
85 – 89
A3
80 - 84
B1
75 – 79
B2
70 – 74
B3
65 – 69
C1
60 - 64
C2
55 – 59
C3
50 - 54
D1
0 – 49
F1
* Cell phones are not allowed to be used in class. Students using cell phone for
any purpose in class (other than an emergency) will be asked to leave the
class.
Announcements:
E-mail will be used to send important announcements, it is therefore important
for you to check your email regularly.
Definition of Wireless Communication

What is Wireless Communication?
Communication through wireless physical media where transmitter and/or receiver do
not connected with each other by a wired or corded circuitry.
Wireless History
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The first wireless networks were developed in the Pre-industrial age.
These systems transmitted information over line of sight distances
using smoke signals, torch signalling, flashing mirrors, carrier
pigeons etc...
Observation stations were built on hilltops and along roads to relay
these messages over large distances.
Wireless History

These early communication networks were replaced first by the
telegraph network (invented by Samuel Morse,1838) and later by
telephone (Alexander Graham Bell ,1876).
Wireless History

In 1895, after the invention of telephone, Marconi demonstrated the
first radio tranmission from the Isle of Wight to 18 miles away, so the
radio communication was born.

Radio owes its development to two other inventions: the telegraph
and the telephone. All three technologies are closely related, and
radio technology actually began as «wireless telegraphy»

Many sophisticated military radio systems were developed during
and after WW2
Wireless History

Radio technology advanced rapidly
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Public and private radio communication
Television
Wireless networking

Early radio systems transmitted analog signals.
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Today most radio systems transmit digital signals.

A digital radio can transmit a continuous bit stream or it can group
the bits into packets known as packet radio.
Wireless History

The first network based on packet radio is ALOHANET (University of
Hawai, 1971).

In this network, a star topology is used and seven campuses
communicated over a central computer.

ALOHANET incorporated the first set of protocols for channel
access and routing in packet radio systems and many of the
underlying principles in these protocols are still in use today.
Wireless History

Later on US military invested significant resources for developing
networks to use in the battlefield and Ad-hoc wireless networks have
been built.
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
They can configure themselves without any established infrastructure.
Speed and performance was not satisfied in early usage but these networks
continue to be developed for military use.
Wireless History

Packet radio networks also found commercial application
in supporting wide area wireless data services


First, introduced in early 1990s. Enable wireless data access with
low speeds 20Kbps (email,file transfer,web browsing)
The introduction of wired Ethernet technology in the
1970s steered many commercial companies away from
radio-based networking.
Wireless History

In 1985, the Federal Communications Commission (FCC) enabled
the commercial development of wireless LAN’s by authorizing the
public use of the Industrial, Scientific and Medical (ISM) frequency
bands for wireless LAN products.
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Good news they do not need to get permission from FCC
Interference problem so low power profile and inefficienct signalling scheme
Poor data rate and coverage problems
Low security and high cost
The result is weak sale.
Wireless History

Most successful application of wireless networking has been the
cellular telephone system.

In 1946, public mobile telephone service was introduced in 25 cities
around the USA

These initial systems used a central transmitter to cover an entire
metropolitan area (Large tower to cover of over 50 km)
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
It has limited capacity.
In 1976, the introduction of mobile telephone service.
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Although 10 million people for New-York city market only 543 paying users can be
served.
Wireless History

During the 1950s and 1960s, AT&T Bell Laboratories developed the
theory and techniques of cellular concept.

The concept of breaking a coverage zone into small cells, each of which reuse
partions of the spectrum to increase spectrum usage at the expense of greater
system infrastructure.

The first analog cellular system deployed in Chicago in 1983.

In 1989, FCC granted additional channels to US cellular service
providers to accommodate the rapid growth and demand.

The second generation of cellular systems, first deployed in the
early 1990s were based on the digital communications.
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
The shift from analog to digital was driven by its higher capacity and improved
cost, speed and power efficiency of digital hardware.
The second generation cellular systems initially provided mainly
voice. Then they gradually evolved to support data services such as
email, internet access and short messaging.
Wireless History

Satellite systems are typically characterized by the height of the
satellite orbit
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The GEOs are seen as stationary from the earth, whereas the
satellites with other orbits have their coverage area change over
time.
The concept of using GEO satellites for communication was first
suggested by the science fiction writer Arthur Clarke in 1945.
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low earth orbit (LEO, roughlt 2000km altitude)
medium earth orbit (MEO, roughlt 9000km altitude)
geosynchronous earth orbit (GEO, roughlt 40000km altitude)
The first deployed satellites Soviet Union’s Sputnik, 1957
NASA Echo-1 in 1960
They are not successful in difficulty of lifting a satellite into such a high orbit.
The first GEO satellite was launched by Hughes and NASA in 1963.
GEO’s then dominated both commercial and government satellite
systems several decades.
Wireless History

GEO satellites have large coverage areas, so fewer satellites are
necessary to provide wide area or global coverage.

However, it takes a great deal of power to reach the satellite and
propagation delay is typically too large for delay constrained
applications like voice.

These disadvantages caused a shift in the 1990s toward lower orbit
satellites.

The goal was to provide voice and data service competitice with
cellular systems. However, the satellite mobile terminals were much
bigger, consumed much power and cost much more than cellular
phones.
Wireless Communication System Definitions
Simplex
Systems
Communication systems which provide only one-way
communication
Communication systems which allow simultaneously two-way
communication.
Full Duplex
Transmission and reception:
Systems
 On two different channels (FDD=Frequency Division Duplexing)
 On two different time slots (TDD=Time Division Duplexing)
(new cordless systems use TDD) using same radio channel
Communication systems which allow two-way communication using
Half Duplex
same radio channel for both transmission and reception. At any given
Systems
time, the user can only be either transmit or receive the information
 A fixed station in a mobile radio system used for radio
communication with mobile stations.
Base Station  Located at the center or on the edge of a coverage region
 Consist of radio channels and transmitter and receiver Antennas
mounted on a tower
 A station intended for use in motion at unspecified locations.
Mobile Station
 May be portable or installed in vehicles
Wireless Communication System Definitions
Forward Channel
Reverse Channel
Control Channel
Subscriber
Transceiver
Handoff
Page
Roamer
Mobile Switching
Center (MSC)
Radio channel used for transmission of information from base station to mobile
Radio channel used for transmission of information from mobile to base station
Radio channel used for transmission of call setup, call request, call initiation
and other control parameters
A user who pays subscription charges for using a mobile communication system
A device capable of simultaneously transmitting and receiving radio signals
The process of transferring a mobile station from one channel to another from
base station to another
A brief message broadcast over the entire service area
A mobile station operates in a service area (market) other than that from which
service has been subscribed
Coordinates the routing of calls. MSC connects the cellular base stations and
the mobiles.
Ex: Mobile Radio Telephony in the U:S:
50 MHz Total Bandwidth in 800 MHz band –
60 kHz for each duplex channel One way bandwidth 30 kHz
Current/Next-Gen Wireless Systems
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Current:
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4G Cellular Systems (LTE-Advanced)
4G Wireless LANs/WiFi (802.11ac)
mmWave massive MIMO systems
Satellite Systems
Bluetooth
Zigbee
Emerging
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5G Cellular and WiFi Systems
Ad/hoc and Cognitive Radio Networks
Energy-Harvesting Systems
Chemical/Molecular
Much room
For innovation
Paging Systems
• Communication systems that broadcast a page from every base station in the
network and send brief messages to a subscriber.
• In modern paging systems, news headlines, stock quotations, and faxes may be
sent.
• Though paging receivers are simple and inexpensive, the transmission system
required is quite sophisticated.
Cordless Telephone Systems
Cordless Telephone Systems
full duplex communication systems
Connects portable hand set to a dedicated base station which is connected
to a telephone line on public switched telephone network PSTN
Range
only over distances of a few tens of meters
Cellular Systems
Base Stations:
Handle full duplex communication
Transmitter and Receiver Antennas
Base Station
Common Air Interface (CAI):
Specifies four channels for
voice transmission
•Forward Voice Channel:
From base station to mobile
•Reverse Voice Channel:
From mobiles to base
Mobile Stations
•Forward Control Channel
•Reverse Control Channel
Moves the call to an unused
Voice channel
MSC=Mobile Switching Center connects all mobiles to PSTN
PSTN=Public Switched Telephone Network
Cellular Systems:
Reuse channels to maximize capacity
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Geographic region divided into cells
Freq./timeslots/codes/space reused in different cells (reuse 1 common).
Interference between cells using same channel: interference mitigation
key
Base stations/MTSOs coordinate handoff and control functions
Shrinking cell size increases capacity, as well as complexity, handoff, …
BASE
STATION
MTSO
Evolution of Cellular Systems
4G/LTE Cellular
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Much higher data rates than 3G (50-100 Mbps)
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Greater spectral efficiency (bits/s/Hz)
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More bandwidth, adaptive OFDM-MIMO, reduced
interference
Flexible use of up to 100 MHz of spectrum
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3G systems has 384 Kbps peak rates
10-20 MHz spectrum allocation common
Low packet latency (<5ms).
Reduced cost-per-bit (not clear to customers)
All IP network
5G Upgrades from 4G
Future Cellular Phones
Burden
for this
performance
is on the backbone network
Everything
wireless
in one device
San Francisco
BS
BS
LTE backbone is the Internet
Internet
Nth-Gen
Cellular
Phone
System
Nth-Gen
Cellular
Paris
BS
Much better performance and reliability than today
- Gbps rates, low latency, 99% coverage, energy efficiency
Wifi Networks
Multimedia Everywhere, Without Wires
802.11ac
• Streaming video
• Gbps data rates
• High reliability
• Coverage inside and out
Wireless HDTV
and Gaming
Wireless LAN
• WLAN which combines data connectivity with
user mobility is designed as an alternative to
the wired LAN to minimize the need for wired
connections.
• WLAN functions are similar to a cellular system
that each AP is a BS that transmits data
between the WLAN and the wired network
infrastructure as illustrated in Figure 5.3.
• Users in the WLAN can seamlessly roam
between APs without dropping their
connections.
• WLAN operates in unlicensed frequency bands
and have gained strong popularity in a number
of vertical markets, including health-care,
academia, hotels and manufacturing.
Wireless LAN Standards

802.11b (Old – 1990s)
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802.11a/g (Middle Age– mid-late 1990s)
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Standard for 2.4GHz ISM band (80 MHz)
Direct sequence spread spectrum (DSSS)
Speeds of 11 Mbps, approx. 100 m range
Standard for 5GHz band (300 MHz)/also 2.4GHz
OFDM in 20 MHz with adaptive rate/codes
Speeds of 54 Mbps, approx. less than 100 m
Many
WLAN
cards
have
(a/b/g/n)
802.11n/ac/ax (current/next gen)
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Standard in 2.4 GHz and 5 GHz band
Adaptive OFDM /MIMO in 20/40/80/160 MHz
Antennas: 2-4, up to 8
Speeds up to 1 Gbps (10 Gbps for ax), approx. 200 ft range
Other advances in packetization, antenna use, multiuser MIMO
Satellite Systems
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Cover very large areas

Different orbit heights
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Optimized for one-way transmission
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GEOs (39000 Km) versus LEOs (2000 Km)
Radio (XM, Sirius) and movie (SatTV, DVB/S)
broadcasts
Most two-way systems went bankrupt
Global Positioning System (GPS) ubiquitous

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Satellite signals used to pinpoint location
Popular in cell phones, PDAs, and navigation devices
Bluetooth

Cable replacement RF technology (low cost)

Short range (10m, extendable to 100m)

2.4 GHz band (crowded)

1 Data (700 Kbps) and 3 voice channels, up
to 3 Mbps

Widely supported by telecommunications,
PC, and consumer electronics companies

Few applications beyond cable replacement
32810.61-Cimini-7/98
IEEE 802.15.4/ZigBee Radios
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Low-rate low-power low-cost secure radio
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Complementary to WiFi and Bluetooth
Frequency bands: 784, 868, 915 MHz, 2.4 GHz
Data rates: 20Kbps, 40Kbps, 250 Kbps
Range: 10-100m line-of-sight
Support for large mesh networking or star clusters
Support for low latency devices
CSMA-CA channel access
Applications: light switches, electricity meters, traffic
management, and other low-power sensors.
Ad-Hoc Networks
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Peer-to-peer communications
 No backbone infrastructure or centralized control
Routing can be multihop.
Topology is dynamic.
Fully connected with different link SINRs
Open questions
 Fundamental capacity region
 Resource allocation (power, rate, spectrum, etc.)
 Routing
Standards

Interacting systems require standardization

Companies want their systems adopted as
standard
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Standards determined by TIA/CTIA in US
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Alternatively try for de-facto standards
IEEE standards often adopted
Process fraught with inefficiencies and conflicts
Worldwide standards determined by ITU-T

In Europe, ETSI is equivalent of IEEE
Evolution of Wireless Standards
4.5G
* Zarrinkoub H., Understanding LTE with Matlab, 2014
HSPA : High Speed Packet Access
HSDPA:High Speed Downlink Packet Access
HSUPA: High Speed Uplink Packet Access
Evolution of Wireless Standards
Peak Data Rates of Various Wireless Standards
Future Wireless Networks
Ubiquitous Communication Among People and Devices
Next-Gen Cellular/WiFi
Smart Homes/Spaces
Autonomous Cars
Smart Cities
Body-Area Networks
Internet of Things
All this and more …
What is the Internet of Things:

Enabling every electronic device to be
connected to each other and the Internet

Includes smartphones, consumer
electronics, cars, lights, clothes, sensors,
medical devices,…

Value in IoT is data processing in the cloud
Different requirements than smartphones: low rates/energy consumption
Body Area Networks
Body-Area
Networks