Personal Handy-phone System Research Articles

Tracking Individual Travel Behavior Using Mobile Phone

Tracking type data collection methods using mobile phone have been developed for monitoring and analyzing individual travel behavior. Previous methods using PHS (Personal Handy phone System) assumed that the location data of base stations were known. This paper shows a location positioning method of a mobile object when the location data of base stations are not available. Instead of base stations, signal strength vectors (reference vectors) are observed at many places in a target area. A mobile object also observes a signal strength vector (target vector). The similarity index of a reference vector and a target vector is used for calculating the location position of a mobile object. This method is applied to tracking travel behavior of tourists in Kobe Kitano area.

ハイテクとローテクの二つの入り口を設けたものづくり導入教育の試み

Basic teaching materials in monozukuri ("creating things") are not very effective at instilling motivation to study engineering among students today, who have grown up in the modern world surrounded by high-tech products. In order to stimulate interest in the study of engineering to such students, we propose teaching of monozukuri that incorporates both high-tech and low-tech approaches. In this paper, we report the results from educational trials of two sets of teaching materials, one high-tech and one low-tech. The high-tech materials project involved the creation of a digital terminal for the Personal Handy-phone System (PHS), and the low-tech materials project involved the creation of a crystal radio made from everyday items found in the home.

A method for expressing mobile propagation loss characteristics in a street microcell system

Data from the received signal-level in the personal handy-phone system commercial communication service are used to evaluate a method for expressing mobile propagation loss characteristics. The standard deviation of the difference between the measured signal level and the signal level given by empirical equations is calculated on the basis of a macrocell mode (loss versus direct distance from base station) and a street microcell mode (classified as base-station road and crossed road). The results show that the expression of street microcell mode is better than that of the macrocell mode.

A system employing high‐quality speech compression technology to produce voice on demand for visually handicapped persons

AbstractWe have developed a voice‐on‐demand system in which a voice reading the latest information such as newspapers and public bulletins or regional information is information‐compressed by a voice coding technique and stored on the disks of a PC server, and then distributed to receivers at the homes of visually handicapped persons via ISDN networks. In the compression of read speech, the low‐rate speech coding technique DualSpeech is developed and introduced. The information content is reduced to about 1/18 with almost no degradation of the quality of the read speech, so that it can be distributed at high speed. Moreover, the one‐megabyte memory embedded in the receiver can store about 60 minutes of the read speech compactly and the stored information content can be retrieved instantly by an index retrieval function. With these merits, the time required in distribution and communication charges are reduced, and a voice‐on‐demand service is realized which has the appeal of allowing repeated listening at any time to information which the visually handicapped persons would like to acquire. Evaluation of the performance of this voice‐on‐demand system indicates that the read speech data can be received in a short time, about 1/8 of the regeneration time, and regenerated speech can be obtained with a high quality equal to that of the personal handy‐phone system (PHS). Moreover, we have performed service experiments using the voice‐on‐demand system employing speech compression for about 50 visually handicapped persons. The following desirable features have become clear from the questionnaire results: enrichment of close‐at‐home information which the visually handicapped persons can select by themselves, increase of the update frequency of the information content, and further enhancement of the operability of the receiver. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(11): 56–70, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10095

Experimental results on indoor electromagnetic wave absorber using magnetic wood

The purpose of this paper is to propose a new type of indoor electromagnetic wave absorber using magnetic wood. This magnetic wood has good electromagnetic wave absorbing characteristics, a low specific gravity, a wood texture and other wood characteristics and can be easily processed. Electromagnetic wave absorbing characteristics were measured for four types of magnetic wood. The sandwich-type magnetic wood demonstrated the best wave absorbing characteristics among the four types of magnetic wood that were studied. The experimental results showed that the proposed indoor electromagnetic wave absorber can be used to suppress the transmission and reception of cellular phone and Personal Handy Phone System (PHS) signals and can be used as a cross protection for indoor wireless Local Area Networks (LAN). This wood can be processed for use in furniture, building materials, and other applications.

The Searching System for Wandering Demented Aged Person using GPS

We proposed a searching system for wandering demented aged person using GPS (Global Positioning System), PHS (Personal Handyphone System) and mobile PC (Personal Computer). There were three subsystems: one base station and two mobile terminals carried by the aged and his family. We focused our system on reducing the mental stress of the family in the sense that, in using our system, the family does not need further assistance from others. The independence of the family is very important. In order to construct this user-friendly system, the mobile terminal for the family consisted of only the necessary input keys and the static station included a touch panel. Furthermore, to clarify intuitively the geometrical relationship between the aged and 'carer-person' in the family, the mobile terminal was able to show their loci on the same digital map in real time, and was automatically able to change the scale of the map using a GIS (Geographic Information System). We were encouraged by the results of the application of our system to a search for the wandering demented aged person.

A practical procedure to prevent electromagnetic interference with electronic medical equipment.

Problems involving electromagnetic interference (EMI) with electronic medical equipment are well-documented. However, no systematic investigation of EMI has been done. We have systematically investigated the causes of EMI. The factors involved in EMI were determined as follows: 1) Electric-field intensity induced by invasive radio waves from outside a hospital. 2) Residual magnetic-flux density at welding points in a building. 3) Electric-field intensity induced by conveyance systems with a linear motor. 4) The shielding capacity of hospital walls. 5) The shielding capacity of commercial shields against a wide range frequency radio waves. 6) The immunity of electronic medical equipment. 7) EMI by cellular telephone and personal handy-phone system handsets. From the results of our investigation, we developed a following practical procedure to prevent EMI. 1) Measurement of electric-field intensity induced by invasive radio waves from outside the hospital and industrial systems in the hospital. 2) Measurement of residual magnetic-flux density at electric welding points of hospital buildings with steel frame structures. 3) Control of the electromagnetic environment by utilizing the shielding capacity of walls. 4) Measurement of the immunity of electronic medical equipment. And 5) Installation of electronic gate equipment at the building entrance to screen for handsets.

A regional Medical Information Sharing System at a Medical Association Hospital Using Personal Handyphone System Data Communication

A regional Medical Information Sharing System at a Medical Association Hospital Using Personal Handyphone System Data Communication

Feasibility of a remote monitoring system for patients with an implantable left ventricular assist device using Personal Handy-Phone System telecommunication technology

We have been developing a remote monitoring system for patients with implanted artificial hearts. The remote monitoring system consists of two digital data links: an electromagnetic transcutaneous digital-data transmission (TDT) system between an artificial heart controller inside the body and a mobile computer outside the body, and a public high-speed data transmission service using PHS (Personal Handy-Phone System) between the mobile computer and a host computer in a hospital. The TDT system mainly consists of an ASK (Amplitude Shift Keying) circuit with carrier electromagnetic wave frequencies of 4MHz and 10 MHz and corresponding demodulation circuit, thin loop coil antennas for transmission and receiving, and a one-chip microcomputer for the alarm system for indicating misalignment of antennas outside the transmittable range to ensure error-free data transmission. In our remote monitoring system, motor current and motor rotational angle data from the implanted controller are framed together by a control code for data error checking and correcting at the receiving site, and the data are sent through the PHS connected to the mobile computer. GPS (Global Positioning System) positioning data are also sent to the host computer with control codes. The host computer calculates pump outflow and arterial pressure and displays the data in real-time waveforms. The host computer also displays the patient's position on the map and the condition of the batteries. The results of this study showed that the driving condition of the artificial heart and the subject's position could be remotely monitored on the host computer. It could be concluded that this monitoring system is useful for remote monitoring of patients with an implanted artificial heart.

Experiment of a Practical Automatic Snowplow

In this study, two kinds of automatic snowplow are experimentally investigated. One is a remote-controlled snowplow that works around residence. Another is an autonomous snowplow that works in wide and simple space such as a car parking lot for a large-scale retail store. The original merchandized snowplow was improved for remote-control that utilizes communication line of P.H.S. (personal Handy-phone System). The autonomous controller utilizes a vision sensor that is composed of CCD video camera and a computer for image processing. In addition, design of practical landmark is examined.

An HTS 21-pole microstrip filter for IMT-2000 base stations with steep attenuation

We developed a 21-pole high-temperature superconductor thin-film microstrip filter with steep attenuation. This filter is applicable in the International Mobile Telecommunications-2000 (IMT-2000) base station receiver system, where high selectivity is needed to avoid interference from signals in the personal handyphone system (PHS) band just below the IMT-2000 band. The out-of-band rejection of this filter 1 MHz below the passband edge is more than 40 dB. Owing to the improvements of the design and the fabrication processes, we also eliminated the need for a tuning process in the fabrication processes in order to reduce the production costs and the turnaround time.

Electromagnetic interference on medical equipment by low-power mobile telecommunication systems

There have been a number of reports of electromagnetic interference (EMI) on electronic medical equipment caused by mobile telecommunication systems. In Japan, the use of the personal handy-phone system (PHS) has greatly expanded within urban areas, PHS handsets transmit EM signals at a frequency of 1.9 GHz and have a peak radiated power of 80 mW. This power level is lower than that of other mobile telecommunication systems. Two studies were carried out. One was to determine whether or not PHS interferes with electronic medical equipment in hospitals. We observed no EMI on electronic medical equipment when the PHS handset was in either the speaking mode or on standby. The second study was to observe EMI from 1.9-GHz signals at several radiation power levels. Although EMI was not observed at the radiated peak power of the PHS handset, EMI on some of the tested equipment was observed when the radiated power was ten or more times higher than that of the PHS handset.

Advantages of low output mobile communication systems in hospitals.

Mobile telephone systems using radio waves with very low power outputs rarely interfere with electronic medical equipment, which allows them to be safely installed in hospitals. The Personal Handy-phone System, PHS, which was developed and is widely used in Japan, is one such system. It has many useful functions including voice communication, string message transfer, e-mail, an answering system limited to selected persons or groups, paging, automatic call transfer, and handset positioning. In this paper we discuss the benefits of these functions confer to hospital communication systems.

Multiple paths protocol for a cluster type network

Nowadays we can access the Internet by carrying a portable computer and using wireless communication. The wireless network with personal handy phone system (PHS) and portable cellular telephone has only rates of tens of Kbps to a few Mbps. Compared with the cable network, the transfer rate cannot generally satisfy a highly developed communication service such as large file transfer and real-time communications. This paper proposes a protocol, SHAKE, for sharing multiple paths in a cluster type network that is a kind of LAN in which some mobile hosts temporarily connect mutually. SHAKE provides the functions for composing a cluster type network, and dispersing traffic efficiently by measuring transfer rate and round-trip time. As a mobile host has only a low transfer capacity for individuals to communicate with the outside, if whole capacities of other hosts which compose a cluster type network are shared, we can get larger transfer capacity and satisfy the required communication services. Copyright © 1999 John Wiley & Sons, Ltd.

Cell size extending effect of the personal handy phone system by means of delay spread control techniques

Cell size extending effect of the personal handy phone system by means of delay spread control techniques

A remote monitoring system for patients with implantable ventricular assist devices with a personal handy phone system.

The usefulness of a remote monitoring system that uses a personal handy phone for artificial heart implanted patients was investigated. The type of handy phone used in this study was a personal handy phone system (PHS), which is a system developed in Japan that uses the NTT (Nippon Telephone and Telegraph, Inc.) telephone network service. The PHS has several advantages: high-speed data transmission, low power output, little electromagnetic interference with medical devices, and easy locating of patients. In our system, patients have a mobile computer (Toshiba, Libretto 50, Kawasaki, Japan) for data transmission control between an implanted controller and a host computer (NEC, PC-9821V16) in the hospital. Information on the motor rotational angle (8 bits) and motor current (8 bits) of the implanted motor driven heart is fed into the mobile computer from the implanted controller (Hitachi, H8/532, Yokohama, Japan) according to 32-bit command codes from the host computer. Motor current and motor rotational angle data from inside the body are framed together by a control code (frame number and parity) for data error checking and correcting at the receiving site, and the data are sent through the PHS connection to the mobile computer. The host computer calculates pump outflow and arterial pressure from the motor rotational angle and motor current values and displays the data in real-time waveforms. The results of this study showed that accurate data on motor rotational angle and current could be transmitted from the subjects while they were walking or driving a car to the host computer at a data transmission rate of 9600 bps. This system is useful for remote monitoring of patients with an implanted artificial heart.

Cell size extending effect of the personal handy phone system by means of delay spread control techniques

Cell size extending effect of the personal handy phone system by means of delay spread control techniques

High-Quality and High-Speed Wireless Multimedia Transmission Technologyfor Personal Handy Phone System

The Personal Handy-phone System (PHS), developed as a PCS, has been very widely accepted. This system offers many benefits as the infrastructure of the mobile data communication services that are expected to be available soon with the popularity of nomadic computing. Data communication systems based on PHS and some applications are proposed in this paper. One of the key technologies, an error control scheme, is also introduced. Three kinds of possible system configurations are discussed as a data communication platform for PHS. One of them has an ARQ function which corrects all errors that occur in the propagation path. Conventional application software on nomadic computers can be used in the mobile environment because this ARQ function is installed as a lower layer protocol. The introduced system connects all mobile computers to all servers that are on the networks which include ISDN, the conventional analog PSTN, cellular networks and PHS networks.

移動体通信網の応用による小児行動モニタ用マーカの研究

A Communication between aged and child is effective to prevent an appearance and a progress of senile dementia. However, it is not effective if the child grow up under poor condition. Nowadays, connection between parents and child is not enough, since many parents are working together for living. So, most of parents do not know a location of their child. A new convenient method to monitor child behavior is developed. Parents are able to know the location of the child using the method. Crimes about the children are going to decrease, since the children are watched by the parents using the method. Personal Handyphone System(PHS)can be applied as an information-network to monitor the location. However, it is important to miniaturize a marker to be utilized for children. It is effective that a reduction of output power of the marker and a time control of oscillation. In this paper, a case of 1mW is simulated and analyzed. If the relay station detect a signal from a marker, the child can be watched. In the result, signal can be detected at zoo and residential area. The location of the child is displayed by the system. The child enjoy oneself or with friends under the monitor with love of one's parents.

Low-power and high-quality signal transmission baseband LSIC for personal communications

This paper presents a very low power consumption one-chip baseband large-scale integrated circuit (LSIC) for personal communication terminals. It comprises a /spl pi//4-shift QPSK modem, an adaptive differential pulse code modulation (ADPCM) codec, a time division multiple access time division duplex (TDMA-TDD) controller and a link access procedure for a digital cordless (LAPDC: Layer-2 protocol) controller. The developed LSIC meets all the specifications of the personal handy-phone system (PHS) standard. By employing a novel coherent demodulator and an ADPCM codec with a click noise suppressor, a higher quality voice transmission has been achieved in a fading environment. In addition, it has 61-kb/s data transmission capability to achieve wireless multimedia services based on PHS. Moreover, the novel circuit configurations of the modem, the ADPCM codec, the TDMA-TDD controller, and the LAPDC controller achieve significant power reduction of the baseband circuits (57.4 mW) of personal communication terminals. It enables very low power consumption wireless multimedia terminals to be achieved based on the PHS common air interface.