BY,

NAME: B.CHAITANYANAME: B.CHAITANYA

BRANCH: ECEBRANCH: ECE

YEAR: 2-2YEAR: 2-2

Abstract

Mobile computing has been undergoing a bit of a renaissance lately. A few years ago it was a simple matter of finding a data-compatible mobile phone, a PC card modem, and a matching cable and installing it as a modem. Then people started to use PDA’s as well. Cell phones started to come with infrared ports to allow communication with laptops. Then cell phones started to come with modems built in. The connecting methods of mobile computing, its introduction, connection types, factors affecting connections, mobile applications and its limitations are explained.

Introduction

What is mobile computing?

A view on portable devices.

  • Distinctionbetween "wireless" and "mobile."
  • MobileDevices
  • Challenges in mobile computing
  • Merits and Demerits
  • Applications
  • Conclusion
  • Bibliography

Introduction

Wireless networking technology has engendered a new era of computing, called mobile computing. Mobile Computing is an umbrella term used to describe technologies that enable people to access network services any place, anytime, and anywhere.

Ubiquitouscomputing and nomadiccomputing are synonymous with mobilecomputing. Mobile computing helps users to be productive immediately by reducing the training requirements associated with traditional automated data collection methods and provides a higher level of portability than keyboard-based systems.

Field-based users can access any information available from the system at any time to make critical business decisions. This information is available at the point of use, wherever and whenever they need it.

Portable devices like laptop and palm top computers give mobile users access to diverse sources of global information anywhere and at any time.

One of the most important and highly publicized recent developments in the PC world has been the introduction of the pen interface. By using a stylus to replace the keyboard, mobile computers are turning thousands of computer illiterate people especially those involved with field-based data collection into computer users. The market potential and breadth of application requirements for mobile computing has prompted numerous hardware and software companies to focus their efforts in providing solutions to the vertical, form-oriented marketplace.

Distinctionbetween "wireless" and "mobile."

Wireless refers to the method of transferring information between computing devices, such as a personal data assistant (PDA), and

a data source, such as an agency database server, without a physical connection. Not all wireless communications technologies are mobile. For example, lasers are used in wireless data transfer between buildings, but cannot be used in mobile communications at this time.

Mobile simply describes a computing device that is not restricted to a desktop. A mobile device may be a PDA, a "smart" cell phone or Web phone, a laptop computer, or any one of numerous other devices that allow the user to complete computing tasks without being tethered, or connected, to a network. Mobile computing does not necessarily require wireless communication. In fact, it may not require communication between devices at all.

Mobile devices

Here we have seven different types of mobile devices:

  • Laptop computers
  • PDA’s and handheld PCs
  • Pagers
  • Smart phones and cellular phones
  • Task devices, such as bar code scanners
  • Blue tooth
  • Bridge

Laptops are typically used and supported in the same way as desktop PCs. In fact, many organizations have replaced desktops with their portable cousins, as the workforce has grown increasingly mobile.

PDA’s, however, are the least planned for and supported devices. They are undergoing rapid evolution and are being brought into organizations in the same way the earliest PCs were. That is, adventurous early adopters buy the devices for their personal use and then ask IT departments to integrate the devices into the corporate IT environment.

Smart phones that allow users to access phone calls, two-way radio transmissions, and paging and data transmissions on one device are also finding applications in hospitals and other situations that have intense and constant need for time sensitive communications.

Pagers that support one- and two-way text messaging are also used in similar situations. Third party vendors most often provide support for these devices.

Task devices such as the parcel tracking devices used by Federal Express (FedEx) and the United Parcel Service (UPS) delivery personnel are most often bought as part of a complete system from a third-party vendor. Because they are frequently mission-critical, most corporations support task devices as rigorously as desktop computers.

Bluetooth:- A short-range wireless standard that specifies radio connections between devices within a 10-meter range of each other. Bluetooth is designed as a Personal Area Network (PAN, or WPAN for "Wireless Personal Area Network") technology with a wide variety of theoretical uses.

Bridge:- A device that connects two local-area networks (LANs), or two segments of the same LAN. Bridges simply forward packets from one segment to another without analyzing or routing messages. This allows them to connect dissimilar networks (e.g., a bridge can connect an Ethernet and Token-Ring network).

Challenges in mobile computing

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.

The major challenges in mobile computing are described including: low bandwidth, high error rate, power restrictions, security, limited capabilities, disconnection and problems due to client mobility.

LowBandwidth

Wireless networks deliver lower bandwidth than wired networks. As a result, mobile applications have to be carefully designed to control the bandwidth consumption. Software techniques required to improve effective bandwidth usage include data compression logging requests to combine multiple short ones, lazy write back, difference-based updates, caching, prefetching, usage of proxy, priority scheduling, etc.

HighErrorRate

The network quality varies as the mobile computer moves across the heterogeneous network connections. The wireless environment exhibits higher error rates, which results in retransmission and affects the Quality of Service. By minimizing the usage of wireless transmission, the data is less exposed to transmission errors. In addition, error correction schemes can be employed to improve performance. However, these schemes also add to the communication overhead and reduce the usable bandwidth.

PowerLimitations

Mobile computers are concerned with the limited power supply, an issue that does not appear in distributed wired environment. Hardware improvements on batteries can help to lengthen the life of a charge and reduce battery weight. In addition, efficient software operations can help to lower the power consumption. Examples include: shifting the processing to a fixed host, aggressively caching and prefetching data to reduce disk traffic, and transmitting less data while receiving more

Security

Security and privacy are of specific concerns in wireless communication because of the ease of connecting to the wireless link anonymously. Common problems are impersonation, denial of service and tapping. The main technique used is encryption. In personal profiles of users are used to restrict access to the mobile units.

Merits

The benefits of automating data collection applications with mobile computing are the reduction of hard and soft costs, enhancement of revenue potential, and a distinct competitive advantage through:

  • Improving the data collection process
  • Improving data accuracy
  • Reducing paperwork
  • Enforcing collection of more complete information
  • Facilitating collection of more useful information
  • Eliminating redundant data entry
  • Reducing administrative costs
  • Reducing billing errors
  • Reducing data backlog
  • Improving information flow
  • Allowing faster adaptation to changing business conditions
  • Increasing responsiveness and customer satisfaction
  • Providing access to previously unavailable information

Demerits

The demerits of the mobile computing are discussed as follows:

  • Information access via a mobile device is plagued by low available bandwidth, poor connection maintenance, poor security, and addressing problems. Unlike their wired counterparts, design of software for mobile devices must consider resource limitation, battery power and display size. Consequently, new hardware and software techniques must be developed. For example, applications need to be highly optimized for space, in order to fit in the limited memory on the mobile devices.
  • 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 dynamic infrastructure is an appropriate way to address this problem.

  • Day by day as the standard of the mobile computing is increasing the boons of mobile computing are changing to banes. Eg: The most deadly terrorist attack occurred on sept 11, 2001.

Applications
New technical and application developments have established that mobile systems can be a cost-effective, efficient, and productive solution in several different types of application environments. They are:- a new generation of satellites, especially Low-Earth Orbit systems (LEOS) are under development with the Internet in mind. Companies like Teledesic and Orbcomm are actively promoting Internet access.

Vertical industries where mobile technology has already been successfully adopted include Consumer Goods, Delivery and Route Sales, Government, Healthcare, Market Research, Pharmaceuticals, Transportation, and Utilities.
Consumer Goods. Typical applications include inventory, merchandising, order entry, and sales automation. Features found in these applications usually provide access to stock and pricing information, monitor promotions, and perform shelf space analysis including number of facings and product age. Customer detail helps reps to act more as consultants than order takers.

Delivery & Route Sales. With fierce competition and an increasing inventory, having timely and accurate information is more important than ever.

Government. Applications center around assessments, inspections, and work orders. Most of these applications involve auditing some sort of facility or process (food service, restaurant, nursing home, child care, schools, commercial and residential buildings).

Healthcare. The focus in this industry has been on automating patient records, medication dispension, and sample collection. A common goal is to leverage mobile computing in the implementation of positive patient identification.

Market Research. Automating the survey process has enabled these companies to get their data more accurately and quickly while being able to customize their queries at will.

Pharmaceuticals. In addition to the reps need to perform account management and call reporting functions, the FDA’s requirement for physician signatures for all drug samples dispensed was an added complication that was eliminated through the use of mobile technology.

Transportation. Transforming freight damage inspections from paper to mobile computing greatly expedites the process and reduces costs by providing on-line pre-shipment inspections. This technology also offers a more efficient means of storing and transmitting maintenance inspection reports. In conjunction with GPS (global positioning systems), mobile computing allows companies to provide better customer service by being continually aware of exactly where any given shipment is when in transit.

Utilities. Eliminating the rekeying of data and providing a means to perform on site analysis are instrumental to an industry that is required to perform inspections on a routine basis.

Conclusion

Mobile computing is rapidly becoming popular, and user demand for useful wireless applications is increasing.

Additionally, this paper shows how these behavioral extensions serve as a powerful abstraction for practical systems.

In this paper, we have looked at issues related to portable devices, merits, demerits and applications in mobile environment.

Because of the banes of mobile computing the security level should be improved.

Bibliography

Terri Watson. : Application design for wireless computing.

Application design for wireless computing : M-Mail: A Case Study of Dynamic Application Partitioning in Mobile Computing

Christine Julien and Gruia-Catalin Roman :Active Coordination in Ad Hoc Networks

Raymond J. Brunsting : Quality of Service Issues in Wireless Networks