MOBILE COMPUTING



MOBILE COMPUTING

Abstract:

In the last few years, the use of portablecomputers and wireless networks has beenwidespread. The combination of both opens the doorto a new technology:

mobile computing.

Mobilecomputing has become the most powerful tool bothfor personal and business use.Mobile computingtechnology has forced the Cellular technology tobring out their best services.This paper starts withgiving very basic idea of mobile computing and thenmoves on to mobile networks.Here we will stop for awhile checking out the cellular network in detailsince mobile computing is closely related to cellulartechnology.This paper also focuses on differentwireless technologies that support mobilecomputing.Though the facilities provided by thistechnology are tremendous ,this is still striving for itsfulfledged performance.The reasons that limit thismobile computing technology and what can be thesolutions to them are also discussed in thispaper.Even after mobile computing technologypenetrating into many fields ,many are not stillaware of its major applications.This paper focuses ondifferent application areas of mobile computing andconcludes by predicting its future.

 

I. I

NTRODUCTION

" 

Mobile Computing constitutes a new paradigm of computing which is expected to revolutionise the waycomputers are used." 

 

George H.Forman

 

Mobile computing 

can be traced back to its first use in the 1990s. Laptops have become the mainstream device which people use back then to keep connected to each other. Since then, countless number of devices has forayed into the market bringing a newer sense of wireless communication. To this date, this type of communication has become the most powerful tool both for business and personal use.

A

.

MOBILE

 

COMPUTING

Mobile computing refers to the technology which enables transmission of data (computing) through portable devices i.e. laptops, cellular phones etc. It refers to being able to use a computing device even when being mobile and therefore changing location These portable devices are known as Mobile devices. Portability is one aspect of mobile computing. Simply defined, mobile computing is the use of a wireless network infrastructure to provide anytime, anywhere communications and access to information.

Mobile computing has three aspects:

•

Mobile communication:

aspect addresses communication issues in ad-hoc and infrastructure networks as well as communication properties, protocols, data formats and concrete technologies

•

Mobile hardware:

i.e. mobile devices or device components.

•

Mobile software:

deals with the characteristics and requirements of mobile applications.

B. MOBILE DEVICES

Mobile devices allow the user to access the wireless world from any point. Many types of mobile devices have been introduced since the 1990.Some of them is:

•Full-featured mobile phones with personal computer-like functionality, or “smart phones”• Laptops and notebooks• Tablet computers• Portable digital assistants (PDAs)• Portable Universal Serial Bus (USB)devices for storage (such as “thumbdrives” and MP3 devices) and for connectivity (such as Wi-Fi, Bluetooth and HSDPA/UMTS/EDGE/GPRS modem cards)• Digital cameras

Radio frequency identification (RFID)and mobile RFID (M-RFID) devices fordata storage, identification and assetmanagement• Infrared-enabled (IrDA) devices suchas printers and smart cards

•

Wearable computer 

•

Carputer 

•

Ultra-Mobile PC

II.MOBILE SYSTEM NETWORKS

Mobile networks are networks of mobile devices,servers and distributed computing worksthat support mobile computing can be classified asfollows.

A. Wireless LAN and Wireless Access Points

WLAN

can be defined as a network inwhich a mobile user connects to a LAN through awireless or radio connection. The advantages of usinga WLAN are numerous, including the flexibilityoffered to overcome limitations of wired networksbecause of space constraints, easy, hassle-free andsimple computing. WLAN allows access to keyinformation and resources without having to “plug-in”, regardless of where the users are in the facility.Access points are stations within a WirelessLocal Area Network (WLAN) that transmit andreceive data. They connect users to the network andcan also serve as the point of interconnection betweenthe WLAN and a fixed wire network. The regioncovered by each of the access points is termed a “HotSpot”.

B.Satellite Networks

In satellite networks, a satellite acts as the centralpoint for the outgoing and incoming data. Thesubscriber needs a satellite dish antenna and atransceiver operating in microwave range. Satellitenetworks are usually a good option for rural areas,where DSL and cable networks are not available.

C. Cellular Networks

In cellular networks, the entire area is divided intocellular regions, each serving a different band of frequencies. The cellular regions are served by a basestation comprising of a transmitter, a receiver and acontrol unit. The base stations are connected to aMobile Telecommunications Switching Office, whichin turn is connected to the public telephone network.

D.Ad-hoc and Sensor Networks

An ad-hoc network is a network in which certaindevices are part of the network for a temporaryduration .i.e. either for a specific communicationsession or while in close proximity to the network.The ad hoc networks are deployed for routing, targetdetection, service discovery, and other needs in amobile environment.Sensor networks are formed by small nodes or “motes” tiny, self-contained, battery-poweredcomputers with radio links that enable the motes toself-organize into a network, communicate with eachother and exchange data. Sensor networks are mostlyregarded as a specialized area of ad-hoc networks.They are most popularly used in military applications,where the topology of the network can keep changingvery often and “currency” of information is of primemost importance.

III.CELLULAR NETWORK INDETAIL

Cellular telephone is a handy portable device, similar to two-way mobile radio.

A cellular network consistsof mobile units linked together to switchingequipment, which interconnect the different parts of the network and allow access to the fixed PublicSwitched Telephone Network 

(PSTN).

Thetechnology is hidden from view; it's incorporated ina number of tranceivers called Base Stations (BS).Every BS is located at a strategically selected placeand covers a given area or 

cell 

- hence the namecellular communications. A number of adjacentcells grouped together form an area

 

and thecorresponding BSs communicate through a socalled Mobile Switching Centre (MSC). The MSCis the heart of a cellular radio system. It isresponsible for 

routing

, or 

switching

, calls fromthe originator to the destinator. 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 andsupplementary services, and for collecting chargingand accounting information. The MSC may beconnected to other MSCs on the same network or tothe PSTN.

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