The development of an embedded wireless modem conforming to advanced mobile phone system and cellular digital packet data standards

Introduced by AT&T Bell Labs in 1970s, today Advanced Mobile Phone Systems (AMPS) - a first generation analog cellular system serve millions of customers in the United States and 55 other countries, and the number of subscribers is still rapidly increasing. Although digital cellular systems are emerging in recent years, research efforts are still being made to the enhancement of AMPS systems because of their popularity. An example is the new Cellular Digital Packet Data (CDPD) standard announced in 1994. CDPD is an overlay of the existing AMPS, and has the capability of transmitting data packets over such an analog cellular network. This thesis intends to first introduce this new technology, and then discusses the design and implementation of an embedded wireless modem which conforms to the CDPD public standard. The emphasis is on software design, implementation, simulation, and test of the modem. The real-time test and demonstration shows that the newly developed modem and related software meet the requirements and specifications in terms of functionality, modularity, robustness, and low power consumption

Networking Support For Mobile Computing

With increasing use of small portable computers, wireless networks and satellites, a trend to support computing on the move has emerged. This trend is known as mobile computing or anytime and anywhere computing. Some people refer it as Nomadic computing. No matter which name is applied, all these terms really imply that a user may not maintain a fixed position in the network. The user is free to roam from one place to another. However the mobile user still expects uninterrupted network access and the ability to run some networked applications. To support such mobility, the user is typically provided a wireless interface to communicate with other fixed and mobile users. The mobile computing environment can be described by the following attributes (a) mobile users, (b) mobile support stations or base stations serving an area, (c) wireless interface, (d) wireless medium with varying channel characteristics (due to fading, noise, interference, etc.) and (e) various applications requiring specific support. A mobile computing environment raises such issues as how to route packets as the mobile user (hosts) moves from one place to the other and how to overcome limitations including limited bandwidth and storage. This tutorial presents an introduction to mobile computing, to the challenges introduced, and to emerging networking infrastructures for mobile computing

Demystifying Wireless Technologies: Navigating Through The Wireless Technology Maze

A significant part of the growth in consumer-to-business electronic commerce is likely to originate from the increasing numbers of mobile computing devices and smart telephone devices. Most of the data from mobile computers will be carried over by emerging wireless networks. Many wireless technologies and standards are now available. As a result, it is becoming increasingly difficult for non-domain experts like managers, to sort through the maze of wireless technologies and standards to make business decisions involving these technologies. This article surveys existing and emerging wireless technologies and uses the Open System Interconnect (OSI) framework to organize the wireless landscape. The survey provides a quick reference to the entire spectrum of wireless technologies in use today

Performance of the IEEE 802.16e sleep mode mechanism in the presence of bidirectional traffic

We refine existing performance studies of the WiMAX sleep mode operation to take into account uplink as well as downlink traffic. This as opposed to previous studies which neglected the influence of uplink traffic. We obtain numerically efficient procedures to compute both delay and energy efficiency characteristics. A test scenario with an Individual Subscriber Internet traffic model in both directions shows that even a small amount of uplink traffic has a profound effect on the system performance

Mobile computing & law enforcement: An Examination of its application in the field and its consequences

The following study has been conducted in the pursuit of a Masters Degree of Science in Information Technology. The functional purpose of this study was to examine three basic concepts (officer efficiency, safety, and arrest rates) within law enforcement and to attempt to determine if a specific type of information technology (wireless data computers) has had any positive impact on those concepts. To that end, the author has reviewed the history of technology in law enforcement and surveyed a group of patrol officers in the Wilmington Police Department. Difficulties associated with gathering research data from law enforcement agencies has also been noted and described. The results garnered from statistical analysis are covered in detail

A Field study to determine the feasibility of establishing remote data transmission of advertising for a local newspaper

In recent years, local newspaper\u27s advertising revenues have been seriously eroded by the presence of competing electronic media. Technological innovation in cable television (CATV), interactive multimedia, broadcast television and Compact Disc-Read-Only Memory (CD-ROM) have proven to be a double-edge sword for local newspaper advertising revenues. On one hand, these technologies provide lower cost, high quality advertisement which target larger, more diverse audiences. On the other hand, the same technological innovations (high speed digital transmission, high quality input and output devices, and the widespread use of portable computing) have created a means for local newspapers to protect their advertising base and realize increased customer satisfaction through on-site interaction in early phases of ad development through remote data transmission. In this context remote data transmission involves the use of high speed transmission facilities capable of transmitting data of rates in excess of 56,000 bits per second. Adobe Acrobat 2.0 was used as a means of maintaining the integrity of the advertisement\u27s elements as part of the transmission process. The author conducted a field experiment to determine the feasibility of remote data transmission of advertising between Advertising Services at Syracuse Newspapers in Syracuse, New York and a well known retailer - Kaufmann\u27s Department Stores. A Kaufmann\u27s ad was converted from PostScript to a Portable Document File (PDF) using Adobe Acrobat 2.0 Pro Distiller. The ad was transmitted to Advertising Services using switched 56 telecommunication line and a modem. Advertising Services transferred the ad into Adobe Acrobat 2.0. The ad was calibrated using -5 Calibration Curve in the AdSEND Calibration based on GammaTrol measurements, press data and evaluations of the press proofs Based on the evaluation of the press proofs, -5 Calibration Curve was the best calibration for Goss press and newsprint paper. The shadow was set at 95%, midtone at 45% and highlight at 0% in AdSEND Calibration. The shadow measured 78%, midtone at 58% and highlight at 0% on the press proof. The shadow measured 65%, midtone at 43% and highlight at 4% on the actual newspaper ad. The author concluded remote data transmission was feasible using a switched 56 telecommunication line, a digital modem and Adobe Acrobat 2.0 for electronic delivery of advertising for newspapers

The Progress in Wireless Data Transport and its Role in the Evolving Internet

The progress of wireless technology through the past 105 years is quantitatively reviewed in this paper. Spectral efficiency and coverage density are both found to increase in a relatively continuous exponential fashion over the entire period with spectral efficiency increasing at about 15% per year and coverage density at about 33% per year. Throughput by wireless technology was not found to follow a single exponential but instead followed an exponential with annual increase of only 5% up to the late 70s and since then (and the introduction of the cellular concept) has followed an exponential with annual increases of greater than 50%. These high rates of progress in the functional performance of wireless technology are an essential enabler for wireless interfaces to become the dominant mode for connecting to the Internet