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apprehensiveheehawNetworking and Communications

Oct 26, 2013 (3 years and 10 months ago)

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Facts


Number of wireless (mobile) phone
subscribers now exceeds number of
wired phone (landlines) subscribers!


US, Bangladesh or anywhere around the
globe


Laptops, palmtops, PDAs, internet
-
enabled phones promise
anytime

untethered

Internet access

6/10/2010

1

Wireless Networks and
Applications

Shamim

Begum

Ph.D.

University of Southern California
2009

6/10/2010

2

Outline


Introduction


Computer networks


Network Classification


Wireless Network


History


Fundamentals


Applications


6/10/2010

3

Introduction


Two or more computers are connected


Why: to share resources


Reliability, performance, cost, information access


Example: playing a DVD movie from a
desktop while watching it from a laptop
that lacks it

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4

Computer Networks

Introduction


Resource sharing


Client/server (centralized resource sharing by
client)


Peer
-
to
-
peer (distributed sharing)


Transmission technology


Broadcast


Point
-
to
-
point


Coverage of geographical area


Local Area network (LAN)


single office or building


Metropolitan area network (MAN)


around a town
or city


Wide area network (WAN)


between different
buildings, towns or even countries


6/10/2010

Network classification

5

Introduction


Transmission media


Guided/wired


data signals guided by
cables/wires


Open cables (0
-
5 MHz)


Twisted pair (0
-
100 MHz)


Coaxial cable (0
-
600 MHz)


Optical fiber (0
-
1 GHz)


Unguided/wireless


Transmission and reception by antennas
(transmitters and receivers)


Types of antenna


Directional (point to point)


Omnidirectional

(broadcast)

6/10/2010

Network classification

6

Introduction


Wireless examples


Broadcast radio or Radio


Pros


installation, cost, flexibility and maintenance


Omni
-
directional


Frequency range 3 KHz
-
300 GHz


Example: all communication with general term
“Radio”, e.g., Mobile telephony, wireless sensors etc.


Microwave


Pros


penetrates wall, very long dist.
c
omm.


Cons


expensive, requires
unobst
. LOS


Terrestrial microwave


long dist. telephone


Satellite microwave


television distr., long dist.
telephone


Infrared

6/10/2010

Network classification

7

Introduction


6/10/2010

Electromagnetic spectrum of medium

8

Outline


Introduction


History


From Telegraph to Radio


Evolution of modern Radio


Fundamentals


Applications

6/10/2010

9

History


From “Telegraph” to “Radio”


1867: Maxwell’s prediction of EM waves
existence


1896: Marconi’s demo on wireless
telegraph, patent award on 1897


1898: wireless telegraph between
England and France


Transoceanic Communication


1901: first wireless communication by
Marconi over Atlantic


6/10/2010

Wireless radio

10

History


Voice over Radio


1914: first voice over radio


1935: Armstrong’s demo on FM


1920
-
40: US police systems converted to mobile
Tx
/Rx


Mobile Telephony to Cellular Mobile Telephony (voice)


1946: First
conn

of mobile user to public switched
telephone net (PSTN)


1940’s to 60’s: mobile uses from 50K to 1.4M


1979: Japan deploys first cellular system


1983: AMPS in US


FDMA cellular
(1G


800 MHz)


1993: CDMA in US
(2G)


Digital, increased capacity (speech compression)


1994: GSM in US


TDMA cellular
(2G


1800 MHz)


2000: CDMA2000

(3G)


3G Vision:
universal global roaming, multimedia (voice, data
and video), increased DR and spectral efficiency


6/10/2010

Wireless radio

11

History


Wireless LAN (packet based data)


1997
-
2009:
WiFi

(Wireless Fidelity)


Connectivity inside buildings (typical WLAN)


1997: IEEE 802.11b


2.4 GHz, DSSS tech





2009: IEEE 802.11n


2.4 and 5 GHz, OFDM,


2004 and 2005:
WiMAX

(Worldwide Interoperability
for Microwave Access)


Wireless Wide area network (WWAN)


Wireless broadband (cable, DSL), full mobility


towards
4G


IEEE 802.16 series


from 2004
upto

2010


OFDM



6/10/2010

Wireless radio

12

Outline


Introduction


History


Fundamentals of wireless networks
1


Taxonomy


Elements


Architectures


Fundamentals


Applications


6/10/2010

13

1 Courtesy: Professor Ahmed
Helmy
, UFL

Wireless network taxonomy


Infrastructure


Hosts connects to base station that connect
to larger Internet


Example: cellular,
WiFi
,
WiMAX


No infrastructure


No base station or central controller


Hosts maintain the connectivity among
themselves


Example: ad hoc networks, Bluetooth


Very useful in emergency, crisis response
and hazardous terrain

6/10/2010

14

Wireless hosts

15

Elements of a wireless network

Network

infrastructure

Wireless
hosts


Laptop
, PDA, IP
phone


Run
applications


Stationary
or
mobile


Research challenges


Mobility


Application
reqs

6/10/2010

Base station

16

Elements of a wireless network

network

infrastructure


Base
station


Typically
connected
to wired network


Relay
-

responsible
for sending packets
between wired
network and
wireless host(s) in
its
“coverage area



e.g., cell towers,

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17

Elements of a wireless network

network

infrastructure


Wireless
link


Connect
mobile(s)
to base station


Multiple
access
protocol coordinates
link access


Research challenges


Environment,
surrounding


antennas

6/10/2010

Wireless link

Infrastructure mode

18

Elements of a wireless network

network

infrastructure


Infrastructure
mode


Base
station
connects mobiles
into wired network


Handoff
: mobile
changes base
station providing
connection into
wired
network


Smooth h/o


6/10/2010

A

B

Ad hoc mode

19

Elements of a wireless network

Ad
hoc mode


No
base stations


Nodes
can only
transmit to other
nodes within link
coverage


Nodes
organize
themselves into a
network: route
among
themselves


Research challenge


Network
dynamics and
stability


Efficient routing

6/10/2010

Cellular telephony network

20

Mobile

Switching

Center

Public telephone

network, and

Internet

Mobile

Switching

Center



Connects
cells to wide area net



Manages
call setup



Handles mobility

MSC



Covers
geographical
region



Mobile
users

attach to network
through BS



Air
-
interface
:

physical and link
layer protocol
between mobile and
BS

Cell

wired network

6/10/2010

Architecture

WiFi
: IEEE 802.11 WLAN

21

Architecture


Wireless
host
communicates with base
station (BS or AP)


Basic
Service Set (BSS)
(aka “cell”) in
infrastructure mode
contains:


Wireless
hosts


Access
point (AP):
base station


Ad
hoc mode: hosts only

BSS 1

BSS 2

Internet

hub, switch

or router

AP

AP

6/10/2010

IEEE 802.15 Personal area network

22

M

radius of

coverage

S

S

S

P

P

P

P

M

S

Master device

Slave device

Parked device (inactive)

P


Less
than 10 m diameter


Replacement
for cables
(mouse, keyboard,
headphones)


Ad hoc mode


Master/slaves
:


S
laves
request permission
to send (to master)


M
aster
grants requests


802.15: evolved from
Bluetooth

spec


2.4
-
2.5 GHz radio
band


6/10/2010

Architecture

IEEE 802.16
WiMAX

23


Infrastructure
mode (like 802.11
and cellular)


Hosts
with
omnidirectional

antenna


BS
-
to
-
BS
backhaul
with point
-
to
-
point
antenna


Unlike
802.11:


range ~ 6 miles
(“city rather than
coffee shop”)


~14 Mbps


point
-
to
-
multipoint

point
-
to
-
point

6/10/2010

Architecture

Outline


Introduction


History


Fundamentals


Applications


Cellular, WLAN, WWAN


Wireless sensor networks

6/10/2010

24

Wireless Sensor Network

6/10/2010

Architecture (Habitat monitoring)

25

Transit Network

Data Service

Courtesy: MainwaringWSNA02



Embedded device



Capability


Sensing


Communication


Storage



Small and cheap

Sensors



Collects data
to BS

Gateway



Send data to
Internet

Base station

Internet



Process


Report

Client Data
processing

WSN Applications

6/10/2010

Environmental monitoring

26

Courtesy: LundquistIPSN03


Yosemite national
park in 2002


Over half of CA’s
water supply



Sensors deployed
4000
-
12,000 ft


Accessibility


Sensors


Water level and temp
(circle)


Stream chemistry
(crosses)


Air pressure (square)


Temp and humidity
(diamond)


Air temp. only
(triangle)

WSN Applications



Coal mine in
Singapore


Automated, 2
nd

largest
production


14 Km long
tunnel, goes
upto

200m in depth


Sensors


Rapidly detect
collapse hole due
to mine quakes


Report safe
location ref for
workers

6/10/2010

Structural monitoring: Coal mine

27

Courtesy: LiIPSN07

WSN Application


TT apps


Vehicle in highways,
battlefields


Human in secure areas


Passing objects affect signals
recvd

by sensor


Event is produces


False alarms possible


Sensors act locally and report
centrally

6/10/2010

Target tracking

28

Courtesy: McErleanACSSC02

WSN Applications


Mercury


wearable
wireless sensor


Motion analysis


Harvard medical hospital
(Code blue project)


Patient care


Parkinson’s disease
monitoring


Epilepsy seizure
detection


6/10/2010

Medical and patient care

29

Courtesy: LorinczSensys09

Summary


Background of Computer network, its
classification to wireless networks


History from the birth to modern
Radio technologies


Fundamentals of wireless networks
and its architecture from Cellular to
WiMAX


Applications of wireless sensor
networks

6/10/2010

30

References



MainwaringWSNA02: A. Mainwaring, J.
Polastre
, R.
Szewczyk
, D.
Culler, and J. Anderson,
Wireless Sensor Networks for Habitat
Monitoring
,
WSNA'02
, September 2002


LundquistIPSN03: J. Lundquist, D.
Cayan
, and M.
Dettinger
.,
Meteorology and Hydrology in Yosemite National Park: A Sensor
Network Application.
,
Information Processing in Sensor Networks
(IPSN)
, April 2003


LiIPSN07: M. Li and Y. Liu,
Underground Structure Monitoring with
Wireless Sensor Networks
,
IPSN
, April 2007


McErleanACSSC02: D.
McErlean

and S. Narayanan,
Distributed
Detection and Tracking in Sensor Networks
,
36th
Asilomar

Conference on Signals, Systems and Computers
, November 2002


LorinczSensys09:
Mercury: A Wearable Sensor Network Platform
for High
-
fidelity Motion Analysis
,
Konrad

Lorincz
,
Bor
-
rong

Chen
,
Geoffrey

Werner
Challen
,
Atanu

Roy
Chowdhury
,
Shyamal

Patel
,
Paolo
Bonato
,
Matt Welsh
, Proceedings of the 7th ACM
Conference on Embedded Networked Sensor Systems
(SenSys'09), November, Berkeley, CA, 2009

6/10/2010

31

Thank you!

Questions or Comments?


Email: shamim.begum3@gmail.com

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