wireless mobile computing · 2016. 4. 1. · jini technology provides users access to resources...

International Journal of Science and Engineering Research (IJ0SER),

Vol 2 Issue 6 june-2014

Vanitha.,Tamilselvan.. . . (IJ0SER) june - 2014

Wireless Mobile Computing

S.Vanitha*1

, V.Tamilselvan*2

*1

Department of software engineering

Gnanamani College of Technology, Namakkl

*2 Department of software engineering,

Gnanamani College of Engineering,Namakkal, Tamil Nadu,India.

Abstract: Integrated Mobile Computing Environment and simulation test bed (MCE) is a software platform to

design, develop, and test algorithms and applications for a network of mobile and static computers. MCE is designed

with the idea of providing users with a transparent system so that an application may be tested on the simulation test

bed and then used directly on the network without any source code changes. MCE provides default functionalities

like routing, location tracking, and handoff along with service access points to add or change services resulting in a

unique integrated environment for development and testing. MCE may also be used as a platform to evaluate and

compare various mobile network algorithms.

INTRODUCTION:

Mobile data communications has become a hotly

debated issue. Interest surrounding paging, circuit-

switched and packet-switched networks has lit the fire for

the debate and the announcement of new-technology

networks is adding fuel to the fire. Voice

telecommunication has already been introduced by the

mobile phone and is spreading around all over the world

like a contagious virus. Data communication started in the

early 80's and has been improving ever since, but with a

great drawback. Using the PSDN (Public Switched Data

Network), it does not allow mobility at all.

MOBILE PHONES:

The fixed line PSTN (Public Switched Telephone

Network) severely limits communications by forcing

people to be present at a particular location for

connection to be established. For many years people have

longed for a truly mobile system that would allow them to

move where they pleased, and yet still be able to make

calls, and more challengingly, receive calls. The above

vision has become a reality and mobile phone is now

becoming a necessity rather than luxury. The need of new

networks that will provide the ability of mobile

communication is met by the introduction of cellular

networks.

CELLULAR NETWORK ARCHITECTURE:

Mobile telephony took off with the introduction

of cellular technology which allowed the efficient

utilization of frequencies enabling the connection of a

large number of users. During the 1980's analogue

technology was used. Among the most well known

systems were the NMT900 and 450 (Nordic Mobile

Telephone) and the AMPS (Advanced Mobile Phone

Service). In the 1990's the digital cellular technology was

introduced with GSM (Global System Mobile) being the

most widely accepted system around the world. Other

such systems are the DCS1800 (Digital Communication

System) and the PCS1900 (Personal Communication

System).A cellular network consists of mobile units




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linked together to switching equipment, which

interconnect the different parts of the network and allow

access to the fixed Public Switched Telephone Network

(PSTN). The technology is hidden from view; it's

incorporated in a number of transceivers called Base

Stations (BS). Every BS is located at a strategically

selected place and covers a given area or cell - hence the

name cellular communications. A number of adjacent

cells grouped together form an area and the corresponding

BSs communicate through a so called Mobile Switching

Centre (MSC). The MSC is the heart of a cellular radio

system. It is responsible for routing, or switching, calls

from the originator to the designators. It can be thought of

managing the cell, being responsible for set-up, routing

control and termination of the call, for management of

inter-MSC hand over and supplementary services, and for

collecting charging and accounting information. The MSC

may be connected to other MSCs on the same network or

to the PSTN.

Mobile Switching Centre

The frequencies used vary according to the

cellular network technology implemented. For GSM, 890

- 915 MHz range is used for transmission and 935 -960

MHz for reception. The DCS technology uses frequencies

in the 1800MHz range while PCS in the 1900MHz range.

Each cell has a number of channels associated with it.

These are assigned to subscribers on demand. When a

Mobile Station (MS) becomes 'active' it registers with the

nearest BS. The corresponding MSC stores the

information about that MS and its position. This

information is used to direct incoming calls to the MS.

If during a call the MS moves to an adjacent cell

then a change of frequency will necessarily occur - since

adjacent cells never use the same channels. This

procedure is called hand over and is the key to Mobile

communications.

As the MS is approaching the edge of a cell, the

BS monitors the decrease in signal power. The strength of

the signal is compared with adjacent cells and the call is

handed over to the cell with the strongest signal. During

the switch, the line is lost for about 400ms. When the MS

is going from one area to another it registers itself to the

new MSC. Its location information is updated, thus

allowing MSs to be used outside their 'home' areas.

MOBILE COMPUTING:

Mobile voice communication is widely

established throughout the world and has had a very rapid

increase in the number of subscribers to the various

cellular networks over the last few years. An extension of

this technology is the ability to send and receive data

across these cellular networks.

This is the principle of mobile computing.

Mobile data communication has become a very important

and rapidly evolving technology as it allows users to

transmit data from remote locations to other remote or

fixed locations. This proves to be the solution to the

biggest problem of business people on the move -

mobility.

In this article we give an overview of existing

cellular networks and describe in detail the CDPD

technology which allows data communications across

these networks. Finally, we look at the applications of

Mobile Computing in the real world.

WIRELESS WORLD:




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Wireless and mobile environments bring different

challenges to users and service providers when compared

to fixed, wired networks. Physical constraints become

much more important, such as device weight, battery

power, screen size, portability, quality of radio

transmission, error rates. Mobility brings additional

uncertainties, as well as opportunities to provide new

services and supplementary information to users in the

locations where they find themselves. In general, most

application software, operating systems, and network

infrastructures are intended for more conventional

environments, and so the mobile, wireless user has great

difficulty exploiting the computational infrastructure as

fully as he or she might. There is an emerging consensus

among researchers that a new architecture and

dynamicinfrastructure is an appropriate way to address

this problem.

As the Internet becomes ever more pervasive, and

wireless access to it becomes more common, there will be

a growing need for middleware that can mediate among

the several parties involved. Infrastructure providers can

provide location-based information to subscribers and

service providers; they can also exploit aggregate and

individual location information to better manage their own

communication infrastructure. Mobile ISPs can provide

value-added services that enhance the user’s awareness of

services in the environment, and provide means of

interacting with those services. Users perceive a rich,

adaptive electronic infrastructure that presents the entire

Internet to them in a convenient, controllable, dynamic

way.

In our research into making this future

environment a practical reality, we have found it useful to

“divide and conquer” the problem into five categories:

content;user services, and adaptive applications;user

services, and adaptive applications;profiles and control

interfaces; network and location services.

BLUETOOTH TECHNOLOGY:.

ORGANIZATION OF BLUETOOTH:

In May of 1998, Intel, Ericsson, Nokia, AIBM and

Toshiba were formed as a Special Interest Group, named

SIG, its goal is to set up a short range radio frequency

wireless technology. By June of 1999, members of SIG

had been increased to 751 members, which includes

Compaq ,Dell ,Motorola ,3Com ,HP, Lucent and

Samsung, and they have all come to a consensus of

royalty free standard in order to lower the technical cost

for making it being widely used.

WHAT IS BLUETOOTH?

Bluetooth is a wireless transferring technology

that enables short-range wireless connections between

desktop and laptop computers, personal digital assistants

(PDAs), cellular phones, printers, scanners, digital

cameras and even home appliances. The principle of

Bluetooth (a chipset) is to transfer information and voices

at the frequency of ISM Band.

Every Bluetooth technology devices do come

with a standard address for you to connect one-to-one or

one-to-seven (to form a Pico-net), with transferring range

up to 10 meters (100 meters to follow), using low power

radio.




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Bluetooth do not only possess high transfer rate

of 1MB/s, it also could be encrypted with pin code. With

hopping rate of 1600 hops per second, it is difficult to be

intercepted and are less interrupted by electromagnetic

wave.

What's the difference between Bluetooth and

other wireless solutions?

The comparison table below tells the difference between

these wireless solutions.

BLUETOOTH MODULE:

THE APPLICATION OF BLUETOOTH:

With Bluetooth technology integrated in an Open

motherboard, you can link your handheld device,

Bluetooth-enabled cellular phone and peripherals within

10-meter distance.

JINI TECHNOLOGY:

Jini is a simple set of Java

classes and services that has

the potential to create its own

revolution because it allows

technology to be exploited in

new ways. Created by Sun

Microsystems as software for networking in all sorts of

electronic devices, services, and applications, Jini lets

them join up easily, seamlessly and gracefully - it is a sort

of plug-and-play capability for spontaneously forming

networks of heterogeneous equipment to share code and

configurations transparently. And Jini has the potential to

radically alter our use of computer service networks, since

it allows and encourages new types of services and new

uses of existing networks.

JINI ADVANTAGES:

Jini developers intended Jini technology as a sophisticated

platform on which to develop network-aware applications.

Jini technology provides users access to resources located

anywhere on the network. Both user and resource

locations can change without affecting the application.

Users, devices, and resources can join and leave the

network without manual reconfiguration. Jini developers

used the Internet as a model for developing their product

and sought to take advantage of the Internet's advantages




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in terms of reliability, scalability, maintenance and

administration, and security.

JINI INFRASTRUCTURE:

Jini is a distributed computing

framework. Hence the participants

in the Jini network are called clients

and servers. A server has an

interface, which is the API that it

presents to the outside world. This

interface is called the service

interface or the service. A server is

hence an implementation of a service.

LOGICAL MOBILITY:

● The process of moving programme functionality from

one processing environment (host) to another.

– Can be anything from interpreted scripts, binary

code, code targeting virtual machines, migration of full

applications etc.

– Can include state information

● Popularised by the emergence of Java

● Categorization into various Paradigms [Fuggetta, Picco,

Vigna 98]

– Client/Server

– Code on Demand

– Remote Evaluation

-- Mobile Agents

ADVANTAGES OF LOGICAL MOBILITY:

● Transparent dynamic (and potentially secure)

Update of an application.

Allows devices to function in scenarios that

manufacturers have not anticipated.

Applications can drop code based on frequency

of use if resources are tight.

Logical Mobility (Mobile Agents) used to

● Decrease User Interaction.

● Decrease Cost of Network Access.

● Lends itself to Batch Processing

● Application can effectively appear to work faster.

APPLICATIONS OF MOBILE COMPUTING:

In many fields of work, the ability to keep on the move is

vital in order to utilize time efficiently. Efficient

utilization of resources (i.e.: staff) can mean substantial

savings in transportation costs and other non quantifiable




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costs such as increased customer attention, impact of on

site maintenance and improved intercommunication

within the business.

The importance of Mobile Computing has been

highlighted in many fields of which a few are described

below:

For Estate Agents

Estate agents can work either at home or out in the field.

With mobile computers they can be more productive.

They can obtain current real estate information by

accessing multiple listing services, which they can do

from home, office or car when out with clients. They can

provide clients with immediate feedback regarding

specific homes or neighborhoods, and with faster loan

approvals, since applications can be submitted on the spot.

Therefore, mobile computers allow them to devote more

time to clients.

Emergency Services

Ability to receive information on the move is vital where

the emergency services are involved. Information

regarding the address, type and other details of an incident

can be dispatched quickly, via a CDPD system using

mobile computers, to one or several appropriate mobile

units which are in the vicinity of the incident. Here the

reliability and security implemented in the CDPD system

would be of great advantage.

In courts

Defense counsels can take mobile computers in court.

When the opposing counsel references a case which they

are not familiar, they can use the computer to get direct,

real-time access to on-line legal database services, where

they can gather information on the case and related

precedents. Therefore mobile computers allow immediate

access to a wealth of information, making people better

informed and prepared.

In companies

Managers can use mobile computers in, say,

critical presentations to major customers. They can access

the latest market share information. At a small recess, they

can revise the presentation to take advantage of this

information. They can communicate with the office about

possible new offers and call meetings for discussing

responds to the new proposals. Therefore, mobile

computers can leverage competitive advantages.

Credit card verification

At Point of Sale (POS) terminals in shops and

supermarkets, when customers use credit cards for

transactions, the intercommunication required between the

bank central computer and the POS terminal, in order to

effect verification of the card usage, can take place

quickly and securely over cellular channels using a mobile

computer unit. This can speed up the transaction process

and relieve congestion at the POS terminals.

THE FUTURE:

With the rapid technological advancements in

Artificial Intelligence, Integrated Circuitry and increases

in Computer Processor speeds, the future of mobile

computing looks increasingly exciting.

With the emphasis increasingly on compact,

small mobile computers, it may also be possible to have

all the practicality of a mobile computer in the size of a

hand held organizer or even smaller.

Use of Artificial Intelligence may allow mobile

units to be the ultimate in personal secretaries, which can

receive emails and paging messages, understand what

they are about, and change the individual’s personal

schedule according to the message. This can then be

checked by the individual to plan his/her day.

The working lifestyle will change, with the

majority of people working from home, rather than

commuting. This may be beneficial to the environment as

less transportation will be utilized. This mobility aspect

may be carried further in that, even in social spheres,

people will interact via mobile stations, eliminating the

need to venture outside of the house.

This scary concept of a world full of inanimate

zombies sitting, locked to their mobile stations, accessing




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every sphere of their lives via the computer screen

becomes ever more real as technology, especially in the

field of mobile data communications, rapidly improves

and, as shown below, trends are very much towards

ubiquitous or mobile computing.

Indeed, technologies such as Interactive

television and Video Image Compression already imply a

certain degree of mobility in the home, i.e. home shopping

etc. Using the mobile data communication technologies

discussed, this mobility may be pushed to extreme. The

future of Mobile Computing is very promising indeed,

although technology may go too far, causing detriment to

society.

Major Trends in Computing

CONCLUSION

We believe that Logical Mobility can bring

innovative solutions to Mobile Computing

applications.

Lack of flexible Middleware exposing Logical

Mobility primitives’ application developers.

Lack of methodology to evaluate the

different approaches.

REFERENCES:

Interview with Mr. Eleftherios Koudounas,

Assistant Commercial Services Manager at

Cyprus Telecommunications Authority

Interview with Dr Leonidas Leonidou, Mobile

Services, Cyprus Telecommunications Authority

Interview with DrZinonasIoannou, Mobile

Services, Cyprus Telecommunications Authority.

wireless mobile computing · 2016. 4. 1. · jini technology provides users access to resources...

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