Introduction to Mobile Computing
CE – TE(C)
Suvarna Chaure
Assistant Professor
Dept. of Computer Engineering,
SIES Graduate School of Technology
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Suvarna Chaure
Mobile Computing
Course Objectives
1. To introduce the basic concepts and principles in mobile computing.
This includes major techniques involved, and networks & systems
issues for the design and implementation of mobile computing
systems and applications.
2. To explore both theoretical and practical issues of mobile
computing.
3. To provide an opportunity for students to understand the key
components and technologies involved and to gain hands-on
experiences in building mobile applications.
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Mobile Computing
Course Outcomes
At the end of the course, the students should be able to
1. To identify basic concepts and principles in computing, cellular architecture.
2. To describe the components and functioning of mobile networking.
3. To classify variety of security techniques in mobile network.
4. To apply the concepts of WLAN for local as well as remote applications.
5. To describe Long Term Evolution (LTE) architecture and its interfaces.
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Mobile Computing Lab
Course Outcomes
At the end of the course, the students should be able to
1. Develop and demonstrate mobile applications using various tools
2. Articulate the knowledge of GSM, CDMA & Bluetooth technologies
and demonstrate it.
3. Carry out simulation of frequency reuse, hidden/exposed terminal
problem.
4. Implement security algorithms for mobile communication network
5. Demonstrate simulation and compare the performance of Wireless
LAN
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Modules
1. Introduction to Mobile Computing
2. GSM Mobile services
3. Mobile Networking
4. Wireless Local Area Networks
5. Mobility Management
6. Long-Term Evolution (LTE) of 3GPP
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Mobile Computing Basics
Mobile Computing is a technology that allows transmission of
data, voice and video via a computer or any other wireless
enabled device without having to be connected to a fixed
physical link. The main concept involves −
•Mobile communication
•Mobile hardware
•Mobile software
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Why Mobile Computing?
• Mobile refers to access in motion, no restriction on geographic location.
• With mobility comes lot of issues, techniques and solutions.
• 80% of the world’s workforce is mobile.
• The demand for mobile communication creates the need for
integration of wireless networks into existing fixed networks
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Two Aspects of Mobility
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Effects of device Portability
Power consumption
– limited computing power, low quality displays, small disks due to limited battery
capacity
– CPU: power consumption ~ CV2f
• C: internal capacity, reduced by integration
• V: supply voltage, can be reduced to a certain limit
• f: clock frequency, can be reduced temporally
Loss of data
– higher probability, has to be included in advance into the design (e.g., defects,
theft)
Limited user interfaces
– compromise between size of fingers and portability
– integration of character/voice recognition, abstract symbols
Limited memory
– limited value of mass memories with moving parts
– flash-memory or ? as alternative
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Importance of Mobile Communication
• Location Flexibility
This has enabled users to work from anywhere as long as there is a connection
established. A user can work without being in a fixed position.
• Saves Time
The time consumed or wasted while travelling from different locations or to the
office and back, has been slashed
• Enhanced Productivity
Users can work efficiently and effectively from whichever location they find
comfortable. This in turn enhances their productivity level.
• Ease of Research
Research has been made easier, since users earlier were required to go to the field
and search for facts and feed them back into the system.
• Entertainment
• Business processes are now easily available
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Applications
Vehicles
– 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
Emergencies
– early transmission of patient data to the hospital, current status, first diagnosis
– replacement of a fixed infrastructure in case of earthquakes, hurricanes, fire
etc.
– Disaster Management like crisis, floods,pandemic, ...
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Applications
Travelling salesmen
– direct access to customer files stored in a central location
– consistent databases for all agents
– mobile office
Replacement of fixed networks
– remote sensors, e.g., weather, earth activities
– flexibility for trade shows
– LANs in historic buildings
Entertainment, education, ...
– outdoor Internet access
– intelligent travel guide with up-to-date
location dependent information
– ad-hoc networks for
multi user games
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Example:Road Traffic Monitoring
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Services Provided
Location aware services
what services, e.g., printer, fax, phone, server etc. exist in the local environment
Follow-on services
automatic call-forwarding, transmission of the actual workspace to the current location
Information services
„push“: e.g., current special offers in the supermarket
„pull“: e.g., where is the Black Forrest Cherry Cake?
Support services
caches, intermediate results, state information etc. „follow“ the mobile device through the
fixed network
Privacy
– who should gain knowledge about the location
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Features of Mobile Communication
High capacity load balancing:.
Scalability:
Network management system:
Role based access control:
Indoor as well as outdoor coverage options:
Network access control: NAC can allow your users to register themselves to the
network.
Mobile device management: Mobile device management can provide control of
how you will manage access to programs and applications.
Roaming: Roaming allows your end-users to successfully move from one access
point to another without ever noticing a dip in a performance.
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Types of Mobile Network
• Designed to connect virtually everyone and
everything together including machines,
objects, and devices.
• Deliver higher multi-Gbps peak data speeds
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Mobile and Wireless Services
http://www.jochenschiller.de/ MC SS05 1.1 Department of Computer Engineering
Wireless Networks in comparison with
Fixed Networks
1. Higher loss-rates due to interference
1. emissions of, e.g., engines, lightning
2. Restrictive regulations of frequencies
1. frequencies have to be coordinated, useful frequencies are almost all occupied
3. Low transmission rates
1. local some Mbit/s, regional currently, e.g., 53kbit/s with GSM/GPRS
4. Higher delays, higher jitter
1. connection setup time with GSM in the second range, several hundred milliseconds for
other wireless systems
5. Lower security, simpler active attacking
1. radio interface accessible for everyone, base station can be simulated, thus attracting calls
from mobile phones
6. Always shared medium
1. secure access mechanisms important
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History of Telecommunication
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Cellular Subscribers World Wide
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Common Services in
Communication: PSTN
Public Switched Telephone Network (Telephone line):
• A PSTN phone number is equivalent to one phone line.
• USE of Analog Signals only
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ISDN
Integrated Services Digital Network
• Digital network to transmit voice, image, video and text over circuit
switched PSTN
• It gives you the options of having more than one Channel (line).
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ADSL: Asymmetric Digital Subscriber
line
• Type of Broadband internet
connection.
• ADSL uses analog sinusoidal carrier
waves for data transmission. The waves
are modulated and demodulated at the
customer premises with ADSL modems.
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Circuit Switched V/S Packet switched
Circuit Switched Network Packet Switched Network
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Simple Reference Model
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Try
Assume that source S and destination D are connected through two
intermediate routers labeled R. Determine how many times each packet
has to visit the network layer and the data link layer during a transmission
from S to D.
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Answer
Figure will give you the clear explanation of the answer. Note that, a router is
considered a Layer 3 device because its primary forwarding decision is
based on the information in the Layer 3 IP packet, specifically the
destination IP address.
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Research Areas in Mobile
Communication
Wireless Communication
– transmission quality (bandwidth, error rate, delay)
– modulation, coding, interference
– media access, regulations
– ...
Mobility
– location dependent services
– location transparency
– quality of service support (delay, jitter, security)
– ...
Portability
– power consumption
– limited computing power, sizes of display, ...
– usability
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Overlay Networks: Global Goal
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Thank You!
(suvarnac@sies.edu.in)
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