The document provides an overview of past, present, and future mobile computing technologies. It discusses early technologies like wireless LANs and cellular networks. Current technologies covered include Bluetooth, mobile IP, wireless ad hoc networks, and RFID. The future of mobile computing is also addressed, with continued advances in areas such as increased bandwidth and integration of computing into everyday objects expected.
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Past, Present and Future of Mobile Computing
1. Past, Present, and
Future of Mobile Computing
Yu Cai
Department of Computer Science
University of Colorado at Colorado Springs
6/2/2005
Yu Cai/MTU Talk
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2. Presentation outline
Introduction
Past
on mobile computing
of mobile computing
Present
of mobile computing
* Wireless LAN
* GSM/GPRS/CDMA
*Bluetooth
* Mobile IP
* Mobile Ad Hoc Network (MANET)
* PDA/SmartPhone/Laptop * Sensor/Zigbee Mesh
* Security
Future
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of mobile computing
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* RFID
3. What is mobile computing?
Mobile computing is to describe technologies that
enable people to access network services anyplace, anytime,
and anywhere,
with portable and wireless computing and communication
devices. --- (where is this referenced? Provide citation!)
Aspects of mobility
User mobility
Between different geographical locations
Between different networks
Between different communication devices
Between different applications
Device portability
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Between different geographical locations
Between different networks
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4. Mobile Computing vs.
Ubiquitous Computing/Pervasive Computing
Mobile Computing is a generic term describing the application of
small, portable, and wireless computing and communication
devices. This includes devices like laptops with wireless LAN
technology, mobile phones, wearable computers and
Personal Digital Assistants (PDAs) with Bluetooth or IRDA
interfaces, and USB flash drives.
Ubiquitous computing (ubicomp, or sometimes ubiqcomp)
integrates computation into the environment, rather than having
computers which are distinct objects. Another term for ubiquitous
computing is pervasive computing. Promoters of this idea hope
that embedding computation into the environment would enable
people to move around and interact with computers more naturally
than they currently do.
-- http://en.wikipedia.org/wiki/
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5. Applications of mobile computing
Vehicles
Medical
Nurses/Doctors in Medical offices are now using Wireless Tablet PCs/WLAN to
collect and share patient information.
Sales
transmission of news, road condition, weather, music via DAB
personal communication using GSM
position via GPS
local ad-hoc network with vehicles close-by to prevent accidents, guidance
system, redundancy
vehicle data (e.g., from busses, high-speed trains) can be transmitted in advance
for maintenance
Sales representatives are using Tablet PCs with Smart phones for presentation,
transmitting/access information among office, hotel, and customer location.
Emergencies
Early transmission of patient data to the hospital, current status, first diagnosis
Provide mobile infrastructure in dealing with Natural Disaster (earthquake,
hurricane, fire), terrorist attacks, war, ...
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6. Natural evolution of computing
More
Flexible
Resource
Usage
Mobile Computing
LANs + WorkStations
Networking
Timesharing
Batch
Single User
OS
Freedom from Collocation
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7. Challenges in mobile computing
Mobility means changes
Hardware
Low bandwidth, high bandwidth variability
Locality adaptation
Higher loss-rates, higher delays, more jitter
Different devices, interfaces and protocols
Location awareness
Devices more vulnerable, endpoint authentication harder
Heterogeneous network
Kbit/s to Mbit/s, bandwidth fluctuation
Security risk
Lighter, smaller, energy management, user interface
Connection setup time, hand-off
Restrictive regulations of frequencies
Frequencies have to be coordinated
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8. History of wireless communication
1896 Guglielmo Marconi,
1907 Commercial Trans-Atlantic Wireless Service
Huge ground stations: 30 x 100m antenna masts
1920 Discovery of short waves by Marconi
First demonstration of wireless telegraphy
Based on long wave, requiring very large transmitters
Cheaper, smaller, better quality transmitters by vacuum tube
1982
1983
1992
1997
1998
Start of GSM in Europe (1G analog)
Start of AMPS in America (1G analog)
Start of GSM (2G digital)
Wireless LAN - IEEE802.11
Iridium satellite system
66
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9. History of wireless communication
1999 Standardization of additional wireless LANs
IEEE standard 802.11b
Bluetooth
WAP (Wireless Application Protocol): access to many
services via the mobile phone
2000 GSM with higher data rates (2.5G digital)
HSCSD offers up to 57,6kbit/s
First GPRS trials with up to 50 kbit/s
2001 Start of 3G systems
IMT - 2000, several “members” of a “family”,
CDMA2000 in Korea, UMTS tests in Europe
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6/2/2005
10. Overview of mobile devices
Pager
• receive only
• tiny displays
• simple text
messages
Sensors,
embedded
controllers
6/2/2005
Smart phone
• voice, data
• simple graphical displays
Wearable device
• human wearable
• non standard I/O
Laptop
• fully functional
• standard applications
PDA
• graphical displays
• character recognition
performance
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12. Overview of wireless services
Data Rates
10 Mbps
Wireless
LAN
IR
1 Mbps
Cellular: GSM,
GPRS, CDMA,
50 Kbps
Satellite
10 Kbps
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Local
Coverage Area
Yu Cai/MTU Talk
Wide
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13. Wireless LAN
IEEE 802.11 standard: a family of specifications for
wireless LAN technology. The IEEE accepted the
specification in 1997.
802.11 specifies an over-the-air interface between a
wireless client and a base station or between Point
AP: Access two
AP
wireless clients.
802.11: up AP 2 Mbps in the Network band.
to
Wired 2.4 GHz
AP
802.11b: up to 11 Mbps in the 2.4 GHz band.
802.11a/g: up to 54 Mbps in the 5/2.4 GHz band.
802.11n: up to 220+ Mbps in the 2.4/5 GHz band (two proposals
not approved yet). Vendors already selling 802.11pre-n devices.
802.11 promises true vendor interoperability. Every
vendor must have a viable 802.11 product strategy.
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14. Wireless LAN Security
WEP: Wired Equivalent Privacy.
A basic wireless LAN security mechanism.
Easy to set up, commonly used.
Don’t rely on WEP for wireless security. There are a number of
flaws in the WEP.
Many wireless home networks don’t even use WEP,
which makes bad situation worse.
MAC address based access control mechanism doesn’t
work.
Use other security mechanisms such as VPN, PEAP and
TTLS.
Research project on PEAP / TTLS in our research group in
University of Colorado.
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15. Wireless Ad Hoc Network
Wireless Ad Hoc Network (peer to peer)
Mobile Ad Hoc Networks (MANET)
A collection of autonomous nodes that communicate with each
other by forming a multi-hop radio network in a decentralized
manner.
No infrastructure, no default router available
“every” node needs to be a router
Host movement frequent
Topology change frequent
Wireless Ad Hoc Sensor Networks
A number of sensors spread across a geographical area.
Limited resources on sensors
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16. Mobile IP
Mobile IP is designed to allow mobile device users to
move from one network to another while maintaining
their permanent IP address.
Motivation:
Changing the IP address is not desired when host moves.
However, traditional scheme requires to change IP address
when host moves between networks.
Mobile IP provides an efficient, scalable mechanism for
node mobility within the Internet. Mobile IP allows
moving devices to maintain transport and higher-layer
connections while moving.
Applications:
Mobile IP is most often found in wireless WAN environments
where users need to carry their mobile devices across multiple
LANs with different IP addresses.
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17. Mobile IP: Basic Idea
Mobile Node (MN)
Home Agent (HA)
2
home network
receiver
3
Internet
foreign
network
COA: ?
Foreign Agent (FA)
1
sender
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1. Sender sends to the IP address of MN,
HA intercepts packet (proxy ARP)
2. HA tunnels packet to COA, here FA,
by encapsulation
3. FA forwards the packet to the MN
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18. Mobile IP: Basic Idea
HA
1
home network
MN
sender
Internet
FA
CN
receiver
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foreign
network
1. Sender sends to the IP address
of the receiver as usual,
FA works as default router
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19. Bluetooth
Bluetooth is used to connect and exchange information
between devices like PDAs, mobile phones, laptops, PCs,
printers and digital cameras wirelessly.
Named after a Denmark king Harold Bluetooth, who is
known for his unification of previously warring tribes.
Low-cost, short range (up to 10m), low power
consumption, license-free 2.45 GHz band.
Using the same frequency range, Bluetooth differs from
Wi-Fi in that
Different multiplexing schemes.
Wi-Fi with higher throughput, greater distances, more expensive
hardware, and higher power consumption.
Applications:
Wireless mouse, wireless headset
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20. RFID: Radio Frequency Identification
RFID is a method of remotely storing and retrieving data
using devices called RFID tags.
Categories:
An RFID tag is a small object, such as an adhesive sticker, that
can be attached to or incorporated into a product.
RFID tags contain antennas to enable them to receive and
respond to radio-frequency queries from an RFID transceiver.
No line-of sight required (compared to laser scanners)
Withstand difficult environmental conditions (cold, frost etc.)
Active RFID: battery powered, distances up to 100 m
Passive RFID: operating power comes from the reader over the
air, distances up to 6 m
Applications:
Automated toll collection: RFIDs mounted in windshields allow
commuters to drive through toll plazas without stopping
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21. GSM
One of the most popular standards for mobile phones in
the world.
Formerly: Groupe Spéciale Mobile (founded 1982)
Now: Global System for Mobile Communication
European standard, moving to North America
More than one billion people use GSM phones as of
2005, making GSM the dominant mobile phone system
worldwide with about 70% of the world's market.
GSM is a cellular network, which means that mobile
phones connect to it by searching for cells in the
immediate vicinity.
One of the key features of GSM is the Subscriber
Identity Module (SIM), commonly known as a SIM card.
The SIM is a detachable smartcard containing the user's
subscription information and phonebook.
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22. GSM Overview
OMC, EIR,
AUC
HLR
GMSC
fixed network
NSS
with OSS
VLR
MSC
VLR
MSC
BSC
BSC
RSS
MS
MS
BTS
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RSS (Radio Subsystem)
NSS (Network and switching subsystem)
OSS (Operation Subsystem)
MS (Mobile Station)
BTS (Base Transceiver Station)
BSC (Base Station Controller)
MSC (Mobile Services Switching Center)
GMSC (Gateway MSC)
HLR (Home Location Register)
VLR (Visitor Location Register)
EIR (Equipment Identity Register)
AUC (Authentication Center )
OMC (Operation and Maintenance Center )
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23. GPRS
GPRS: General Packet Radio Service
It is a mobile data service available to users of GSM
mobile phones. It is often described as "2.5G“.
GPRS is packet-switched which means that multiple
users share the same transmission channel, only
transmitting when they have data to send.
GPRS provides moderate speed data transfer, by
allocating unused cell bandwidth to transmit data.
Poor bit rate in busy cells
Usually, GPRS data is billed per kilobytes of information
transceived
In 3G mobile systems like UMTS (Universal Mobile
Telecommunication System), voice and data services
will be mixed in a normal communication.
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24. PDA
Personal digital assistants (PDAs or palmtops)
handheld devices that were originally designed as personal
organizers, but became much more versatile over the years.
A basic PDA usually includes a clock, date book, address book,
task list, memo pad and a simple calculator.
One major advantage of using PDAs is their ability to
synchronize data with desktop, notebook and desknote
computers.
The currently major PDA operating systems are:
Palm OS by PalmSource, Inc
Windows Mobile (Windows CE) by Microsoft
BlackBerry by Research In Motion
Symbian by a group of companies
According to a Gartner market study, the overall market
for PDAs shrunk by 5% in the first quarter (Q1) of 2004,
compared to Q1 2003.
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6/2/2005
25. Satellite Systems
Like cellular systems, except that the base stations (i.e.,
satellites) move as will as mobile devices
Satellite coverage attractive for areas of world not well
served by existing terrestrial infrastructure: ocean areas,
developing countries
IRIDIUM
Motorola
Voice, Data (2.4 kbps), Fax, Location Services
66 satellites in 6 polar orbits (780 km)
Failed project
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26. Future mobile and wireless networks
Shift industrial paradigm from piecewise solutions to
end-to-end information systems
Improved radio technology and antennas
Core network convergence
IP-based, quality of service, mobile IP
Ad-hoc technologies
smart antennas, beam forming, multiple-input multiple-output
(MIMO) 802.11N
dynamic spectrum allocation
spontaneous communication, power saving, redundancy
Simple and open service platform
intelligence at the edge, not in the network (as with IN)
more service providers, not network operators only
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27. Integrated mobile computing
Integration of heterogeneous fixed
and
mobile networks with varying
transmission characteristics
regional
vertical
handover
metropolitan area
campus-based
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in-car,
in-house,
personal area
Yu Cai/MTU Talk
horizontal
handover
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29. Literature
Jochen Schiller – Mobile Communications
Ivan Stojmeniovic – Handbook of Wireless Networks and Mobile Computing
Andrew Tanenbaum – Computer Networks
James D. Solomon – Mobile IP, the Internet unplugged
Charles E. Perkins – Ad-hoc networking
Papers, papers, papers, …
Mobile Computing Courses
MIT: http://nms.lcs.mit.edu/6.829-f01/
Stanford: http://www.stanford.edu/class/cs444n/
UC Berkley: http://www.cs.berkeley.edu/~adj/cs294-1.f00/
UT Austin: http://www.cs.utexas.edu/users/ygz/395T/
http://kunz-pc.sce.carleton.ca/sce536/
http://www.cs.unc.edu/~dewan/290/s02/lectures/lectures.htm
http://www.cs.arizona.edu/classes/cs630/fall01/630-1/contents.htm
http://www.cs.ucsb.edu/~cs290i_mc/index.html
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#11: Sensors can be mobile if they are mounted on robots. See CMU’s minibots http://www.contrib.andrew.cmu.edu/~rjg/millibots/millibot_project.html
Cotsbots at Berkeley http://www-bsac.eecs.berkeley.edu/projects/cotsbots/