Transcript Mobile Computing Teknik Informatika-Semester

MOBILE COMPUTING
D10K-7D02
MC00: Pengantar Mata Kuliah
Dr. Setiawan Hadi, M.Sc.CS.
Program Studi S-1 Teknik Informatika
FMIPA Universitas Padjadjaran
Outline
• Introduction on mobile computing
• Past of mobile computing
• Present of mobile computing
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Wireless LAN
GSM/GPRS/CDMA
Bluetooth
Mobile IP
Mobile Ad Hoc Network (MANET)
PDA/SmartPhone/Laptop
Sensor/Zigbee Mesh
RFID
Security
• Future of mobile computing
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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
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Between different geographical locations
Between different networks
Between different communication devices
Between different applications
– Device portability
• Between different geographical locations
• Between different networks
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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.
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Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Applications of mobile computing
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Vehicles
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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
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Medical
– Nurses/Doctors in Medical offices are now using Wireless Tablet PCs/WLAN to collect
and share patient information.
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Sales
– Sales representatives are using Tablet PCs with Smart phones for presentation,
transmitting/access information among office, hotel, and customer location.
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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, ...
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Natural evolution of computing
More
Flexible
Resource
Usage
Mobile Computing
LANs + WorkStations
Networking
Timesharing
Batch
Single User
OS
Freedom from Collocation
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Challenges in mobile computing
• Mobility means changes
• Hardware
– Lighter, smaller, energy management, user interface
• Low bandwidth, high bandwidth variability
– Kbit/s to Mbit/s, bandwidth fluctuation
• Security risk
– Devices more vulnerable, endpoint authentication harder
• Heterogeneous network
– Different devices, interfaces and protocols
• Location awareness
– Locality adaptation
• Higher loss-rates, higher delays, more jitter
– Connection setup time, hand-off
• Restrictive regulations of frequencies
– Frequencies have to be coordinated
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
History of wireless communication
• 1896 Guglielmo Marconi,
– First demonstration of wireless telegraphy
– Based on long wave, requiring very large transmitters
• 1907 Commercial Trans-Atlantic Wireless Service
– Huge ground stations: 30 x 100m antenna masts
• 1920 Discovery of short waves by Marconi
– Cheaper, smaller, better quality transmitters by vacuum tube
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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 satellites
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Overview of mobile devices
Pager
• receive only
• tiny displays
• simple text
messages
Sensors,
embedded
controllers
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
Overview of development
cellular phones
1981:
NMT 450
1G
2G
1984:
CT1
1987:
CT1+
1988:
Inmarsat-C
1991:
CDMA
1991:
D-AMPS
1992:
Inmarsat-B
Inmarsat-M
1993:
PDC
1994:
DCS 1800
1989:
CT 2
1991:
DECT
1998:
Iridium
2000:
GPRS
2.5G
analogue
wireless
LAN
199x:
proprietary
1997:
IEEE 802.11
1999:
802.11b, Bluetooth
2000:
IEEE 802.11a
2003:
IEEE 802.11g
2007?:
IEEE 802.11N
2001:
IMT-2000
3G
4G?
1980:
CT0
1982:
Inmarsat-A
1983:
AMPS
1986:
NMT 900
1992:
GSM
cordless
phones
satellites
20??
Fourth Generation?
digital
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Overview of wireless services
Data Rates
10 Mbps
Wireless
LAN
IR
1 Mbps
Cellular: GSM,
GPRS, CDMA,
50 Kbps
Satellite
10 Kbps
Wide
Local
Coverage Area
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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 two wireless clients.
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802.11: up to 2 Mbps in the 2.4 GHz band.
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.
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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.
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Wireless Ad Hoc Network
• Wireless Ad Hoc Network (peer to peer)
– 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
• Mobile Ad Hoc Networks (MANET)
– Host movement frequent
– Topology change frequent
• Wireless Ad Hoc Sensor Networks
– A number of sensors spread across a geographical area.
– Limited resources on sensors
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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.
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Mobile IP: Basic Idea
Mobile Node (MN)
Home Agent (HA)
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home network
Internet
3
receiver
foreign
network
COA: ?
Foreign Agent (FA)
1
sender
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
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Mobile IP: Basic Idea
HA
1
home network
sender
Internet
FA
foreign
network
1. Sender sends to the IP address
of the receiver as usual,
FA works as default router
CN
receiver
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
MN
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
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
RFID: Radio Frequency Identification
• RFID is a method of remotely storing and retrieving data using
devices called RFID tags.
– 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.)
• Categories:
– 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
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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.
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
GSM Overview
OMC, EIR,
AUC
HLR
GMSC
fixed network
NSS
with OSS
VLR
MSC
VLR
MSC
BSC
BSC
RSS
MS
MS
BTS
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 )
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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.
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
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:
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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.
Yu Cai/MTU Talk
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
24
6/2/2005
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
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Future mobile and wireless networks
• Shift industrial paradigm from piecewise solutions to end-toend information systems
• Improved radio technology and antennas
– smart antennas, beam forming, multiple-input multiple-output (MIMO)
802.11N
– dynamic spectrum allocation
• Core network convergence
– IP-based, quality of service, mobile IP
• Ad-hoc technologies
– 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
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
Integrated mobile computing
Integration of heterogeneous fixed and
mobile networks with varying
transmission characteristics
regional
vertical
handover
metropolitan area
campus-based
horizontal
handover
in-car,
in-house,
personal area
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016
IP-based next generation network ?
SS7 signalling
server farm,
gateways, proxies
PSTN, CS core
broadcast
gateways
MSC
IP-based
core
SGSN
BSC
GSM
firewall, GGSN,
gateway
router
Internet
access
points private
private
WLAN
WPAN
RNC
UMTS
public
WLAN
Mobile Computing Teknik Informatika-Semester Ganjil 2015-2016