Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
2001-06-21
2002-02-19
Le, Thanh Cong (Department: 2684)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
Reexamination Certificate
active
06349211
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a position display system of a mobile terminal, a center station therefor, and a mobile terminal thereof. Particularly, the present invention relates to a position display apparatus of a mobile terminal employing a small zone communication system, a system therefor, and a mobile terminal thereof.
2. Description of the Background Art
A method of detecting the position of a mobile of interest to the present invention is disclosed in Japanese Patent Publication No. 6-93650, for example. According to the present publication, waves from a plurality of repeaters are received at respective mobiles in a mobile communication system for carrying out communication between a repeater and a mobile via a wave. By using a coverage contour of a reception electric field level from each repeater obtained in advance, the range in which a mobile can be located corresponding to each reception level is obtained to detect the current position of a mobile from the overlap of each range.
However, it is difficult to draw the coverage contour in the frequency range used for a general mobile wireless telephone system and, therefore, it is not practical. The reason is that when an intensity of the electric field is to be measured, the fixed value is seldom obtained due to the fact that the electric field value changes depending on the time elapsed and holding attitude or holding direction of the detector owing to a multipath or fading caused by a geography which is affected by building, rows and moving vehicles. As a result, the detected values constantly vary within the range of some dB to some ten dB (microvolts). Therefore, such a system can be applicable only to locate rough position of vehicles moving high speed. However, such a system cannot be applied to the system wherein the location of a man or a vehicle is detected with a precision of some 10 meters.
There are various conventional methods to detect the position of a mobile vehicle or object. Means generally used for detecting the position on the ground and in the streets includes MCA (Multi-Channel Access), AVM (Automatic Vehicle Monitoring System), and GPS (Global Positioning System). Each will be described hereinafter.
(1) MCA
Today, a great number of vehicles for various delivery and transportation such as those of a delivery service company are seen all over the streets. When the dispatch center of a delivery service company wants to inform delivery or reception of an object to one of the delivery vehicles running in town upon receiving a call from a customer, it is common to send the instruction to the vehicle located closest to that customer from the standpoint of time and efficiency. In general, most of the delivery vehicles have a wireless such as of a MCA mounted. Conventionally, the dispatch center contacts the delivery vehicle considered to be running closest to that client by wireless. If the contacted vehicle is actually located near that client, a relevant instruction is provided to that vehicle. If the vehicle is located far away in contrary to the dispatch center's expectation, other vehicles are contacted sequentially until an appropriately located vehicle is identified. It was common to carry out such confirmation procedures.
(2) AVM
AVM is a practical system that can grasp the current position and state of activity of a running vehicle. This system includes a fixed station (operation control center), a repeater (user operation center), a sign post, and a mobile station. This system is already employed to dispatch taxis and the like efficiently.
(3) GPS
This system is generally employed to identify the position of a mobile vehicle. It is already commercially available as a navigation system for vehicles.
The above-described systems are known as conventional methods for detecting the position of mobile vehicles and objects.
A problem encountered in a MCA will be set forth in the following. If the driver of a vehicle also has to handle the delivery (simply referred to as “driver” hereinafter), the driver must leave the vehicle near the customer's destination to deliver or receive an item to or from the customer in an apartment or a building of an enterprise. Since the driver is remote from the vehicle during the door delivery or reception, there is a possibility that an inquiry of the position of the vehicle from a wireless of the dispatch center is not responded.
The dispatch center may not easily catch a delivery vehicle near the client even though the client has urgent needs. There was a problem that a complaint was filed of delayed service from customers.
Furthermore, the dispatch center must take the trouble to contact the driver of the mobile vehicle to have the driver's current location described orally in this MCA method. The driver must be frequently contacted through a wireless to accurately grasp the current position of the vehicle. This is not only tedious, but also places a considerable burden on the driver. In practice, the center side will contact a vehicle arbitrarily by a wireless to reach an appropriate vehicle after repeating contact to several vehicles. There was a problem that confirmation of the position information is troublesome.
In the AVM, a sign post provides the position information. However, such sign posts are installed only in the coverage area of the service vehicle. Naturally, there is a limit in using this system over a wide area range. There is also a problem that the sign post zone is so large that specification of the position of a mobile station becomes too rough to result in low precision of the position. There is also a limit in reducing the size and weight of the mobile station since the output power of the transmitter is 1 W. There is also a problem that the position information of a mobile station must be transmitted to the center station through a taxi wireless and the like, which is rather tedious. Furthermore, extension of the sign posts causes increase in the facility cost.
As to the GPS system, the mobile vehicle per se can confirm its own position. However, additional communication means is required to transmit the position information to the center side. Reduction in size, weight, and cost as a terminal system cannot be achieved.
There are also position confirmation devices that emits a weak wave and that can be carried by children, the aged, and handicapped individuals. However, the coverage area is extremely limited with such a weak wave that is allowed according to the current Wireless Telegraphy Act. Such position confirmation devices are not practical.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide a position display system of a mobile terminal that can have its position detected at a low cost and with high accuracy.
Another object of the present invention is to provide a mobile terminal that allows position detection at a low cost and at high accuracy.
A further object of the present invention is to provide a center apparatus that is employed in a position detection system of a mobile terminal at a low cost and at high accuracy.
Still another object of the present invention is to provide a system that allows automatic transmission of position information of a mobile terminal carried by a driver and the like to a center apparatus even when the driver is remote from a vehicle.
A still further object of the present invention is to automatically provide the position of a mobile terminal carried by an individual to a center side apparatus without manual operation.
Yet a further object of the present invention is to provide a positioning system that can easily determine a propagation pattern of a wave.
A position display system of a mobile terminal according to an aspect of the present invention employs a small zone communication system. A repeater is provided in respective regions of a plurality of small zones. The position display system of a mobile terminal includes a mobile terminal carrying out communication with a repeat
Iwagami Ryuichi
Koshima Hiroaki
Kumamoto Katsuhiko
Kurokawa Hiroyuki
Muya Kimio
Ace K Computer Co., Ltd.
Cong Le Thanh
McDermott & Will & Emery
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