Cellular Mobile Telephone Environment

Cellular mobile telephone systems are rapidly going into service throughout the Continental United States. They are being installed in a large variety of vehicles both of domestic and of foreign manufacture. In this paper we discuss the physical, climatic, and electronic environments which cellular telephones may expect to encounter in nationwide service. We also discuss procedures used to evaluate the ability of a cellular phone to operate without failure in these environments and to avoid interfering with the increasingly complex vehicular electronic systems.

A cellular mobile telephone system is usually divided into service areas that are employed for different mobility management needs. For instance, sites in the system are grouped into location areas that are used to find mobiles and terminate incoming calls. In this way, the system only needs to track the movement of users when they cross from one service area to another. Still, since the tracking is done using radio bandwidth that is needed for telephone calls, it is important to carefully design the service areas to minimize the mobility management load. The authors define the characteristics that are needed in the service areas for digital cellular systems and state the service area design problem as a graph partitioning optimization problem where the goal is to minimize the diameter of the resulting subgraphs. A heuristic technique is then proposed to design service areas in a systematic and efficient way. This technique achieves better utilization of system resources and produces service areas whose characteristics are close to optimal. >

Optimal Paging in Cellular Mobile Telephone Systems

Digital cellular telephone interaction with implantable cardioverter-defibrillators.

SUMMARYLong‐distance trips are generally under‐reported in typical household surveys, because of relative low frequency of these trips. This paper proposes to utilize location data from cellular phone systems in order to study long‐distance travel patterns. The proposed approach allows passive data collection on many travelers over a long period of time at low costs. The paper presents the results of a study that applies cellular phone technology to assess trips at the national level. The method was specifically designed to capture long distance trips, as part of the development of a national demand model conducted for the Economics and Planning Department of the Israel Ministry of Transport. The method allows the construction of origin–destination tables directly from the cellular phone positions. The paper presents selected results to illustrate the potential of the method for transportation planning and analysis. Copyright © 2011 John Wiley & Sons, Ltd.

The authors describe an integrated mobile communications traffic analysis of voice, data and image by a cellular mobile telephone system. They report the results of lost-call and simulation analysis under various traffic conditions. A newly developed universal protocol, an ARQ-based protocol adapted for land data transmission, is considered, along with an forward error correction (FEC)-based protocol which is the adaptive error control protocol adopted for mobile high-speed data transmission. It is found that the integrated mobile communications service can be provided by the present analog cellular system. When used with a 4800 bit/s CCITT V.27 ter modem, this newly developed protocol increases the throughput to 120%. This new protocol can handle data transmission on burst error-prone radio channels if the bit error rate (BER) is less than about 5*10/sup -2/. >

The noise exists in almost all environments such as cellular mobile telephone systems. Various types of noise can be introduced such as speech additive noise which is the main factor of degradation in perceived speech quality. At some applications for example at the receiver of a telecommunication system, the direct value of interfering noise is not available and there is just access to noisy speech. In these cases the noise cannot be cancelled totally but it may be possible to reduce the noise in a sensible way by utilizing the statistics of the noise and speech signal. In this paper the proposed method for noise reduction is Bayesian recursive state-space Kalman filter, which is a method for estimation of a speech signal from its noisy version. It utilizes the prior probability distributions of the signal and noise processes, which are assumed to be zero-mean Gaussian processes, to implement the noise reduction. The function of Kalman filter is assessed for SNR values of -5 dB and 5 dB respectively. Evaluation results indicate that this method of noise reduction yields better speech perceived quality and efficient results.

One of the goals of digital cellular radio communication systems is described as reducing frequency spectrum congestion, for which the implementation of cellular packet switched data is considered. Due to the bursty nature of many data applications, one solution for conserving RF spectrum is to multiplex packet data from multiple mobile stations into RF channels. In essence, the packet-switched RF channels become an additional traffic concentration point. The author proposes such an adaptation to digital cellular mobile telephone systems and points to necessary extensions of the existing US cellular signaling standard to make such an implementation possible. >

The article following, written by one of the lead engineers in the project, describes the development of AMPS, the first cellular telephone system in the United States. As noted, the project ran for over 12 years and required the services of a vast number of engineers at AT&T's Bell Labs. The hundreds of millions of people currently using cellphones, smart phones, and all the other mobile wireless equipment available in the United States, as well as everywhere else in the world, often take these devices and the infrastructure behind them for granted. Until the cellular concept was recognized, it wasn 't clear that many mobile phones could simultaneously share the same channels in a local area. With the cellular concept agreed on, problems such as tracking of cell phones and handoff from cell to cell had to be resolved. Computerized base stations had to be designed and tested. A myriad other important development and design issues and problems had to be resolved. Dick Frenkiel very clearly describes the various engineering problems that had to be solved, step by step, sometimes quite painstakingly. He gives credit to the many teams of Bell engineers who worked on this project. He also points out policy issues involving the FCC that had to be resolved. Competition for scarce radio spectral space was fierce. Competing engineering companies and telephone operators had to be assuaged. In the meantime, I urge you to read on through this exciting description of the genesis of cellular telephony in the United States.

Superstorm Sandy, and similar disasters, have demonstrated the vulnerability of the nation's cellular telephone systems. Difficulties include overloads when usage suddenly increases; physical destruction of tower sites; and lack of sustained backup power. In contrast, US terrestrial broadcasters have a proven track-record to supply emergency information reliably, over large geographical areas and for as long as needed, as witnessed in the New York and New Jersey areas as well as in New Orleans (Katrina). Furthermore, digital television service to the home is now extended to mobile digital television (mobile DTV) serving portable and handheld devices including those in high speed vehicles. Mobile DTV is currently deployed in 50 major US cities by more than 140 stations with many more in the planning stages. Recently, the ATSC (Advanced Television Systems Committee) has also standardized the Mobile Emergency Alert System (M-EAS). M-EAS can provide both the familiar text "crawl" emergency alerts, and more complex and useful rich media information such as maps and video. M-EAS can be implemented in stand-alone devices, in cellular telephones, and/or in accessory hardware for existing devices.

The FCC has opened a new area of mobile telephone service with the allocation of the 800 MHz band for cellular mobile phone service. A joint effort by General Electric and Northern Telecom has resulted in a unique cellular mobile phone system. This paper discusses the land station and mobile portion of the system developed by General Electric.

The mobile phone industry has experienced an explosive growth in recent years. Mobile phone subscriber numbers have passed the 1.6 billion mark at the end of 2004. The emerging markets such as China, India, and Brazil contribute this growth. In China, the number of mobile subscribers has already surpassed the number of fixed landline phone subscribers. In Korea, the number of mobile phone Internet subscribers is 34.53 million people or 72% of the population in June 2004 (APEC, 2005). Mobile e-commerce (m-commerce) makes business mobility a reality. Mobile users can access the Internet at anytime and anywhere with ubiquitous, inexpensive computing infrastructure. Mobile wireless services are ranging from mobile phone networks to wireless local area networks. The service provided by mobile phone systems has achieved huge success. Mobile phone users originate from all walks of life and include almost all age groups—from teenagers to retired people. It creates a new method of personal communication without location constraints. As telecommunication technologies are converging at fast speed. We will study mobile phone and personal digital assistant (PDA) related to mobile and wireless telecommunication. Hence, m-commerce is defined as electronic commerce carried out in handheld devices such as mobile phone and PDA through mobile and wireless telecommunication networks.

PURPOSE: While designing new products, engineers look to standards to develop the envelope of the project. While these specifications help in determining design goals, the real world often has more strenuous requirements than any specification can foresee. METHODS: Evaluations were made of systems that a typical patient might encounter that emit EMI, RFI as well as ESD. The VAD system was exposed to these systems and the levels of EMI, RFI, and ESD were measured and the effects on the device analyzed. The system was exposed to the EMI/RFI of a fully responding fire station and the inside of an ambulance. The VAD system passed through different types of anti-theft systems, was exposed to household appliances and cellular telephone systems. Finally, the VAD systems received electrostatic shocks applied to various parts of the VAD system and were passed through current and next generation security systems as used in airports. RESULTS: Development of the MicroMed DeBakey VAD system began with close adherence to international specifications as well as systems that the patient might encounter in his/her everyday world. The MicroMed VAD system functioned properly throughout the testing performed. CONCLUSION: With the rise of complex electronic control systems for VAD products, close attention must be paid not only to medical device standards, but to devices and systems that a patient might encounter that were designed to different standards or to no standards at all. The design of a successful device requires that the control electronics be designed for these environments, rather than attempting to shield susceptible electronics from these EMI/RFI/ESD sources.

This paper surveys frequency assignment problems coming up in planning wireless communication services. It particularly focuses on cellular mobile phone systems such as GSM, a technology that revolutionizes communication. Traditional vertex coloring provides a conceptual framework for the mathematical modeling of many frequency planning problems. This basic form, however, needs various extensions to cover technical and organizational side constraints. Among these ramifications are $T$-coloring and list coloring. To model all the subtleties, the techniques of integer programming have proven to be very useful. The ability to produce good frequency plans in practice is essential for the quality of mobile phone networks. The present algorithmic solution methods employ variants of some of the traditional coloring heuristics as well as more sophisticated machinery from mathematical programming. This paper will also address this issue. Finally, this paper discusses several practical frequency assignment problems in detail, states the associated mathematical models, and also points to public electronic libraries of frequency assignment problems from practice. The associated graphs have up to several thousand nodes and range from rather sparse to almost complete.

Wireless teleradiology and fax using cellular phones and notebook PCs for instant access to consultants.