Personal Handy-phone System Research Articles

Problem Based Learning Theory Oriented Portable Medical Training Platform

With the rapid development of information technology, many countries attached great importance on how to develop and maintain the quality of education of doctors and imported information technology to develop a new medical training platform. This study proposes a new portable medical training platform that integrates the structured text to present the result of doctor's diagnosis, the digital images, and the concept of Problem-Based Learning teaching method, and uses intelligent lecture assistance mechanism in clinical teaching. Furthermore, we built a set of Short Message Service transmission functions used on Personal Handyphone System to remind the instructor for further interaction after class with learners (interns or physicians). As for learners, they can use mobile device to practice remedial courses anytime. The proposed portable learning platform changes the traditional teaching method into an intelligent tutoring mechanism. As a result, the core competencies of medical profession can be cultivated to foster excellent medical personnel.

Diffusion of Mobile Telephony in China: Drivers and Forecasts

Analyzing mobile telephony diffusion involves identifying drivers and forecasting growth using a growth model. However, to our knowledge, no framework for model selection exists. To eliminate ad hoc model selection, this study presents a novel model-comparison method based on an analysis of mobile telephony diffusion in China, which accounts for one-fifth of global mobile telephony subscriptions. Determinants of the diffusion rate are then analyzed using the most appropriate model identified by the proposed model-comparison method in terms of minimum root-mean-square error. Empirical results identify the Gompertz model as the best model for diffusion forecasting. The three most significant determinants are low-cost mobile handsets, prepaid services, and personal handy-phone system (PHS) services. All of these determinants contribute to meeting the demand in China's low-end market. This study combines the proposed model-comparison method with estimates of determinants of diffusion rate to improve analysis and forecasting accuracy for mobile telephony diffusion. Moreover, model comparisons using data from eight representative countries (Brazil, China, France, Germany, India, Russia, the U.K., and the U.S.) provide a valuable reference for model selection for mobile telephony diffusion.

Reported functional impairments of electrohypersensitive Japanese: A questionnaire survey

An increasing number of people worldwide complain that they have become electromagnetic hypersensitive (EHS). We conducted a questionnaire survey of EHS persons in Japan. The aim was to identify electromagnetic fields (EMF) and plausible EMF sources that caused their symptoms. Postal questionnaires were distributed via a self-help group, and 75 participants (95% women) responded. Reported major complaints were “fatigue/tiredness” (85%), “headache”, “concentration, memory, and thinking” difficulty (81%, respectively). Seventy-two per cent used some form of complementary/alternative therapy. The most plausible trigger of EHS onset was a mobile phone base station or personal handy-phone system (37%). Sixty-five percent experienced health problems to be due to the radiation from other passengers’ mobile phones in trains or buses, and 12% reported that they could not use public transportation at all. Fifty-three percent had a job before the onset, but most had lost their work and/or experienced a decrease in income. Moreover, 85.3% had to take measures to protect themselves from EMF, such as moving to low EMF areas, or buying low EMF electric appliances. EHS persons were suffering not only from their symptoms, but also from economical and social problems.

Development of a Telecare System Based on ZigBee Mesh Network for Monitoring Blood Pressure of Patients with Hemodialysis in Health Care Centers

In Taiwan, the number of the patients needing dialysis increases rapidly in recent years. Because there is risk in every hemodialysis session, monitoring physiological status, such as blood pressure measurement every 30 min to 1 h is needed during about 4 h hemodialysis process. Therefore, an assisted measurement on blood pressure is needful in dialysis care centers. Telecare system (TCS) is regarded as one of important technique in the medical care. In this study, we utilized ZigBee wireless technique to establish a mesh network for monitoring blood pressure automatically and data storage in medical record system for display and further analysis. Moreover, while the blood pressure exceeds the normal range, the system could send a warning signal to remind, or inform the relatives and clinicians in health care center through the personal handy-phone system (PHS) immediately. The proposed system provides an assisted device for monitoring patients' blood pressure during hemodialysis process and saving medical manpower.

Electromagnetic environments in roadways of underground coal mines and a novel testing method

The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products, as well as a fundamental space for mine monitoring, surveillance, communications and control systems. An investigation of electromagnetic interference in coal mines is essential for the enhancement of performances of these systems. In this study, a new field method is provided in which radiated emission tests in coal mine laneways have been carried out. We conclude that: 1) the wiring motor vehicles can radiate interference with a bandwidth up to 1 GHz and with an amplitude 10 dBμV/m higher than the background noise; 2) the PHS (Personal Handy phone System) mobile communication system can cause interference 40 dBμV/m higher than the background noise; 3) an interference 25 dBμV/m higher than the background noise can be generated during the communication at a working bandwidth of 48.8 MHz; and 4) power cables, battery vehicles as well as mechanical and electrical dong rooms have little effect on the electromagnetic radiation environment in coal mine tunnels.

Precise Positioning Method for Logistics Tracking Systems Using Personal Handy-Phone System Based on Mahalanobis Distance

Focusing on the Personal Handy-phone System (PHS) positioning service used in physical distribution logistics, a positioning error offset method for improving positioning accuracy is invented. A disadvantage of PHS positioning is that measurement errors caused by the fluctuation of radio waves due to buildings around the terminal are large, ranging from several tens to several hundreds of meters. In this study, an error offset method is developed, which learns patterns of positioning results (latitude and longitude) containing errors and the highest signal strength at major logistic points in advance, and matches them with new data measured in actual distribution processes according to the Mahalanobis distance. Then the matching resolution is improved to 1/40 that of the conventional error offset method.

INNOVATION DIFFUSION: MOBILE TELEPHONY ADOPTION IN CHINA

The rapid diffusion of mobile telephony is an important subject in diffusion studies of innovation. This study attempts to learn how mobile telephony diffuses in China, which has the most mobile telephone subscribers worldwide, in terms of the appropriate growth model and forces driving the diffusion. To identify the appropriate growth model, this study compares the fitness and forecasting ability of three conventional models — the Logistic, Bass, and Gompertz models. The determinants of the diffusion rate are then analyzed based on the most appropriate model. Empirical results, based on data for mobile telephone subscribers in China for 1986–2007, indicate that the Gompertz model performs best. Moreover, the four determinants for the diffusion rate are: number of fixed-line telephone subscribers, the low cost of mobile handsets, pre-paid service and the personal handy-phone system (PHS) service.

A Fast RSSI using Novel Logarithmic Gain Amplifiers for Wireless Communication

This paper presents a fast received signal strength indicator (RSSI) circuit for wireless communication application. The proposed circuit is developed using power detectors and an analog-to-digital converter to achieve a fast settling time. The power detector is consisted of a novel logarithmic variable gain amplifier (VGA), a peak detector, and a comparator in a closed loop. The VGA achieved a wide logarithmic gain range in a closed loop form for stable operation. For the peak detector, a fast settling time and small ripple are obtained using the orthogonal characteristics of quadrature signals. In 0.18-㎛ CMOS process, the RSSI value settles down in 20 ㎲ with power consumption of 20 ㎽, and the maximum ripple of the RSSI is 30 ㎷. The proposed RSSI circuit is fabricated with a personal handy-phone system transceiver. The active area is 0.8 × 0.2 ㎟.

A New Signaling Architecture THREP with Autonomous Radio-Link Control for Wireless Communications Systems

This paper presents a new signaling architecture for radio-access control in wireless communications systems. Called THREP (for THREe-phase link set-up Process), it enables systems with low-cost configurations to provide tetherless access and wide-ranging mobility by using autonomous radio-link controls for fast cell searching and distributed call management. A signaling architecture generally consists of a radio-access part and a service-entity-access part. In THREP, the latter part is divided into two steps: preparing a communication channel, and sustaining it. Access control in THREP is thus composed of three separated parts, or protocol phases. The specifications of each phase are determined independently according to system requirements. In the proposed architecture, the first phase uses autonomous radio-link control because we want to construct low-power indoor wireless communications systems. Evaluation of channel usage efficiency and hand-over loss probability in the personal handy-phone system (PHS) shows that THREP makes the radio-access sub-system operations in a practical application model highly efficient, and the results of a field experiment show that THREP provides sufficient protection against severe fast CNR degradation in practical indoor propagation environments.

Regulating Wireless Communications Towers: Taiwan’s Experience in Comparative Perspective

As the number of people who own and use mobile telephones grows, more base stations are needed to carry the “traffic.” New features, enabled by the Third Generation Mobile Telecommunication System (“3G”) and Worldwide Interoperability for Microwave Access (“WiMAX”), such as internet access and multimedia services, require more and more information, or data, to be transmitted. The transmission of these large quantities of data increases the requirement for base stations.1 By mid-2007, there were over 50,000 wireless communication towers in Taiwan. Of these, about 26,000 were designed for the Second Generation Mobile Telecommunication System (“2G”), 6,000 for the 3G, and about 16,000 for the Personal Handy-phone System (“PHS”).2 Typically a wireless communication tower consists of an equipment cabinet, an antenna that sends and receives radio waves to and from mobile telephones, and a structure that supports the antenna.3 Each base station provides coverage for a given area. Base stations can be a few hundred meters apart in major cities or several kilometers apart in rural areas.4 The transmitting power of any particular base station is variable and depends on several factors, including the number of calls and the distance between the base station and the mobile telephone making the call. From a legal perspective, those “base stations,” “antenna” and “radio waves” are subject to substantive and procedural rules.5 This paper focuses on the conflict between operators and the community, common approaches used to regulate base stations and their associated problems, as well as the procedural issues of granting permission for cellular tower construction. After examining the regulatory framework for dealing with the construction of cellular towers, I propose some solutions. In particular, I analyze the issues from a procedural perspective, advocating a way forward that will help eliminate some of the problems caused by the conflict between the regulator, the telecommunications industry, and the local community. [1] In this article I use the terms “base station,” “cellular tower,” “wireless tower,” and “wireless communications tower” interchangeably. [2] The Public Statement of the Former Deputy Chief Commissioner of NCC, EPOCH TIMES, available at http://tw.epochtimes.com/bt/6/4/27/n 1300414.htm (last visited Oct. 20, 2008). [3] Office of Communications, Audit of Mobile Phone Base Stations – Information Sheet, http://www.ofcom.org.uk/sitefinder/audit-info (last visited Oct. 14, 2008). [4] Id. [5] See generally Jeffrey A. Berger, Efficient Wireless Tower Siting: An Alternative to Section 332(C)(7) of The Telecommunications Act of 1996, 23 TEMP. ENVTL. L. & TECH. J. 83 (2004). See also Robyn Durie, Challenges Faced in Providing Mobile Broadband Services, 11 COMPUTER AND TELECOMMUNICATION LAW REVIEW 66-72 (2005).

Novel Microstrip Antenna With Rotatable Patch Fed by Coaxial Line for Personal Handy-Phone System Units

An enhanced microstrip antenna is proposed that incorporates a patch that rotates around the inner conductor of the coaxial line or dielectric shaft and a novel coaxial line feeding technique that offers constant electromagnetic coupling. This proposal addresses the disadvantages in our previous patch antenna in which the resonant frequency diverges from the center frequency of the personal handy-phone system (PHS) band and the bandwidth decreases as the patch rotates because of the changing electromagnetic coupling between the patch and microstrip line due to the patch rotation. We verify that this enhanced patch antenna achieves the antenna gain of approximately 0 dBd, which is the same as that of the previously proposed antenna, while suffering no significant gain degradation due to unit inclination over inclination angles from plusmn45deg compared to a conventional quarter-wavelength whip antenna, which experiences a degradation of approximately 2.7 dB. We show that the maximum resonant frequency separation from the center frequency of the PHS band is reduced to 15 MHz from 31.4 MHz of the previous antenna using the novel coaxial line feeding technique. The effective bandwidth needed for PHS is achieved over the inclination angles of -20deg to +40deg. Approximately 93% of the total bandwidth needed for PHS is achieved while the previous microstrip line type achieved only 58% coverage; accordingly, an adequate bandwidth for PHS use is obtained.

A Mobile Network-based Multimedia Teleconference System for Homecare Services

Because most research and development for homecare services have focused on providing connections between home and service centers, the goal of the present work is to develop techniques and create realtime communications to connect service centers and homecare workers in mobile environments. A key technical issue for this research is how to overcome the limitation of bandwidth in mobile media and networks. An effort has been made to balance performance of communication and basic demands in telehealth through optimized system design and technical implementation. Implementations using third generation (3G) Freedom Of Mobile multimedia Access (FOMA) and Personal Handyphone System (PHS) were developed and evaluated. We conclude that the system we developed based on 3G FOMA provides sufficient and satisfactory functions for use in homecare services.

A Study of Radio Zone Length of Dual-Polarized Omnidirectional Antennas Mounted on Rooftop for Personal Handy-Phone System

This paper proposes a dual-polarized omnidirectional antenna for base-station antennas that are mounted on the rooftops of buildings. The antenna suppresses the degradation in the received-signal level due to the inclination of mobile antennas in the personal handy-phone system (PHS). The proposed polarization-diversity antenna is comprised of a dielectric-loaded slotted-cylinder antenna for horizontally polarized waves and a conventional collinear array antenna for vertically polarized waves in a height-diversity configuration. The structure of the proposed antenna and its fundamental characteristics, such as the input impedance and radiation pattern, are shown. The change in the radio zone length (RZL) due to the inclination angle of the mobile antenna is measured to estimate the improvement offered by the proposed antenna in an urban area. It is shown that the RZLs of the collinear antennas in line-of-sight (LOS) environments are decreased by 73% when the mobile antenna is inclined at 90 , whereas the proposed polarization-diversity antenna restrains the degradation to approximately 20%, regardless of the inclination angle without downtilt and from 20% to 40% for a 15 downtilt. The RZLs of the collinear tilt antennas in non-LOS (NLOS) environments are below approximately 20%, compared to those of the collinear tilt antennas for the LOS route. We show that the RZLs in the NLOS environments are short compared to those for the LOS environments in microcell systems such as PHS with a high-elevation base station, even when the polarization-diversity technique is applied to the base station.

Telemedicine System for Patients on Continuous Ambulatory Peritoneal Dialysis

Over recent decades, rapid progress in information and telecommunications technology has led to the application of these technologies in the medical field. In 1999, we reported on a telemedicine system (version 1.0) that used an automated peritoneal dialysis machine to collect data on patients with end-stage renal disease. After 2002, we focused on using cellular telephones in a new telemedicine system (version 2.0) to monitor patient data at home, including blood pressure (BP), heart rate, body weight, urine volume, and blood glucose. By 2003, we had developed a fully automatic system called I-converter (version 3.0) to collect data from a fully automatic device and send it via cellular telephone. After the fully automatic device measures a patient's BP, I-converter sends the data directly to the main server in our central data center. That server is directly connected to Web site by application service provider (ASP) technology. Recently, to make the system simpler, we developed a new version called D-converter (version 4.0). The telephone used in this new system is a Personal Handy-phone System (PHS). The PHS has several advantages: high-speed data transmission, low power output, little electromagnetic interference with medical devices, and easy locating of patients. The D-converter system uses a small computer and a PHS card called a Dopa card. Our telemedicine systems monitor continuous ambulatory peritoneal dialysis (CAPD) patients at home. For elderly and handicapped patients, these systems are very advantageous because they reduce visits to the outpatient clinic. In addition, data can be monitored at the patient's home in real time. The present paper reports our recent advances in telemedicine systems for CAPD patients.

A 0.25-$\mu$m CMOS 1.9-GHz PHS RF Transceiver With a 150-kHz Low-IF Architecture

We present a 1.9-GHz Personal Handy-phone System (PHS) transceiver, fully integrated and fabricated in 0.25-mum CMOS technology. The receiver is based on a 150-kHz low-IF architecture and meets the fast channel switching and DC-offset cancellation requirements of PHS. It includes a low-noise amplifier (LNA), a downconversion mixer, a complex filter, and a programmable gain amplifier. A fractional-N frequency synthesizer achieves seamless handover with a 25 mus channel switching time and a phase noise of -121 dBc/Hz at a 600-kHz offset frequency, with compliant ACS performance. The receiver provides -105 dBm sensitivity and 55 dBc ACS at a 600-kHz frequency offset. The transmitter is based on the direct modulation architecture and consists of an upconversion mixer and a pre-driver stage. The gain of the pre-driver is digitally controllable to suit any type of commercial power amplifier. The transmitter shows a 3% EVM and a 65 dBc ACPR at a 600-kHz offset frequency. The whole transceiver occupies 15.2 mm2 and dissipates 70 mA in RX and 44 mA in TX, with a 2.8-V supply

A Method of Utilising Lcation Data Obtained by Mobile Communication Devices for Evaluation of Individual Trip-Chaining Behaviors in a Commercial Institution

Urban activation demands policies which consider mutual relations among purchase activities and trip-chaining behaviors of individuals. Observation of individual trip-chaining behaviors, which gives basis of the consideration, can be achieved by applying mobile communication technology devices. We focus upon PHS (Personal Handyphone System) as one typical system of short-range radio communication. A methodology of observing individual trip-chaining in a large-scale commercial building is proposed. The method consists of 1) every-minute positioning of individual, and 2) discrimination of moving/stay. The paper describes the method and a result of field test conducted in an underground shopping center.

The Effectiveness of the Installation of a Mobile Voice Communication System in a University Hospital

In large hospitals, collaborative clinical practice is currently emphasized, with members of various departments expected to work as a team. The importance of accurate communication among the team members is of utmost importance. To improve such communication, the introduction of mobile voice communication systems has received much attention in Japan. Shimane University Hospital also introduced a Personal Handy-phone System (PHS) for doctors. In the traditional setting, much time was wasted searching for doctors through multiple calls on fixed-line telephones. In order to measure the effectiveness of our system, the change in the number of calls made on fixed-line telephones before and after PHS installation was compared. The total number of calls was reduced by more than 35%, and the number of calls to the wards on weekdays was reduced by half. Mobile telecommunication systems with small output power, such as PHS, are known to cause little interference with medical devices which makes it possible to use mobile voice communication safely in hospitals. The improvement in communication by this systems resulted in an improvement in labor efficiency.

IEEE 802.11 wireless LAN implemented on software defined radio with hybrid programmable architecture

This paper describes a prototype software defined radio (SDR) transceiver on a distributed and heterogeneous hybrid programmable architecture; it consists of a central processing unit (CPU), digital signal processors (DSPs), and pre/postprocessors (PPPs), and supports both Personal Handy Phone System (PHS), and IEEE 802.11 wireless local area network (WLAN). It also supports system switching between PHS and WLAN and over-the-air (OTA) software downloading. In this paper, we design an IEEE 802.11 WLAN around the SDR; we show the software architecture of the SDR prototype and describe how it handles the IEEE 802.11 WLAN protocol. The medium access control (MAC) sublayer functions are executed on the CPU, while the physical layer (PHY) functions such as modulation/demodulation are processed by the DSPs; higher speed digital signal processes are run on the PPP implemented on a field-programmable gate array (FPGA). The most difficult problem in implementing the WLAN in this way is meeting the short interframe space (SIFS) requirement of the IEEE 802.11 standard; we elucidate the potential weakness of the current configuration and specify a way of implementing the IEEE 802.11 protocol that avoids this problem. This paper also describes an experimental evaluation of the prototype for WLAN use, the results of which agree well with computer-simulation results.

Tracking individual travel behaviour using mobile phones without information from base stations

Data collection methods that use mobile phones have been developed for tracking, monitoring, and analyzing travel behaviour. Previous methods using a Personal Handy Phone System (PHS) assumed that the location data of base stations were known. This paper shows a positioning method for a mobile object when base station location data are unavailable. Instead of base stations, signal strength vectors (reference vectors) are observed at many places in a target area. Mobile objects also observe a signal strength vector (target vector). A similarity index of reference and target vectors is used to calculate the location of a mobile object. This method tracked the ambulatory behaviour of tourists in an urban setting.

Proposal and performance evaluation of wireless AO/DS system employing PHS

The Always On/Dynamic ISDN (AO/DI) system adaptively switches between packet switching and circuit switching in response to the traffic volume. In this paper, we propose a wireless AO/DI system based on the Personal Handyphone System (PHS), present an overview of this system, and perform an evaluation by a computer simulation of the channel occupation ratio and the call loss ratio of the system. The traffic model assumes an application such as WWW or electronic mail, and the performance is evaluated. The results show the effectiveness of the wireless AO/DI technology as the subscriber capacity of the entire system increases. Furthermore, the middleware for the wireless AO/DI and the terminal adapter for the wireless AO/DI are tested. The performance evaluation results of actual equipment are presented. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(5): 10–19, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20175