JP2523857B2 - Transmission mobile communication system - Google Patents

Abstract

PURPOSE:To realize a low cost system, to miniaturize the mobile terminal equipment and to save power consumption by using optical transmission for an outgoing line from a fixed equipment to a mobile equipment and adopting radio wave transmission for an incoming line. CONSTITUTION:An incoming signal from a mobile equipment 1 is sent to a fixed equipment 2 by means of a radio wave and connects to a wired network 20. Moreover, an outgoing signal is sent from the fixed equipment 2 to the mobile equipment 1 by utilizing the means of light space transmission. Thus, the size of the mobile equipment 1 is made small, the power consumption is reduced and low cost is attained. That is, since an optical receiver is used for the reception system, direct detection is attained and handled as a base band signal, then the circuit integration and power saving of the circuit are far easily implemented in comparison with the radio system. Moreover, since the transmission system utilizes the radio, the transmission indoor is attained with minute power less than the optical transmission.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission mobile communication system such as a cordless telephone, a remote control device or a portable information device, which is used at home or in a room such as an office. .

2. Description of the Related Art In recent years, cordless telephones have been put into practical use, and their use is rapidly spreading in homes and offices. Mobile communication terminals in homes and offices are becoming smaller and smaller, as seen in cordless telephones, and some communication functions are required for mobile information processing terminals such as those found in electronic organizers. It seems that the communication device and the information processing device will be integrated. For this reason, it is expected that the mobile communication system in the room or in the office will first be low in cost, and then the miniaturization and low power consumption of the mobile terminal will become more important in the future.

Problems to be Solved by the Invention However, currently practically used systems have various limitations.

 First, the problem of the conventional example will be considered with reference to FIG.

FIG. 5 is a system conceptual diagram of a cordless telephone currently on the market. In the figure, 1 is a mobile mobile terminal. 2 is a fixed machine, which is usually connected to a wired telephone network. The mobile unit 1 and the fixed unit 2 are provided with two uplink / downlink radio channels, and the mobile unit 1 and the fixed unit 2 are connected via the two radio channels.
The wired network of is connected. A plurality of mobile devices 1 can be used, and a multi-channel access system can be adopted in which a different wireless channel can be set for each mobile device. Although this method has already been put to practical use and technically seems to be no problem, normally two frequencies are allocated (uplink (transmission from mobile station to fixed station)) and downward (transmission from fixed station to mobile station). The fact that a duplexer (or antenna duplexer) is required for two-way communication and a reception filter (RF, EF) for removing interference is essential, making it difficult to simplify the wireless circuit. Yes, there is a problem in cost reduction.

Also, an indoor transmission system using light instead of wireless has been put into practical use, and is used for a transmission system of a computer terminal. In this case, the device is usually fixed or semi-fixed, and while moving It is rarely used for communication. Also, because the downlink is a fixed device, it is possible to secure a high-output and high-quality transmission line, but the uplink cannot be increased because the transmission output of the mobile device is limited, and the transmission quality deteriorates compared to the downlink. It has the drawback of being easy.

An object of the present invention is to solve the problems that the existing system has and to reduce the cost of the transmission mobile communication system, downsize the mobile terminal device, and save power.

Means for Solving the Problems First, the present invention comprises a fixed device and a mobile device which is a portable mobile terminal device, wherein optical transmission is used for a downlink from the fixed device to the mobile device. In a transmission mobile communication system using radio wave transmission from the mobile unit to the fixed unit in the uplink, transmission of light in the downlink in a zone where radio waves are transmitted between the first fixed units but light does not propagate. A second stationary machine having a function is provided so as to be branched from the first stationary machine.

Secondly, the present invention secondly receives a signal by a radio wave from a mobile device, converts the signal as it is or after performing some processing, then converts the signal into an optical signal, and a personal computer or the like existing in a room. It has a fixed machine for sending data to the information processing device and for transmitting remote control signals for TV, audio, video devices and the like.

Effect The present invention utilizes the optical space transmission method for the downlink (transmission from the fixed device to the mobile device) and the transmission method by radio waves for the uplink (transmission from the mobile device to the fixed device) to transmit the light and the radio waves. It reduces reception interference and facilitates separation.

Examples Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a transmission mobile communication system according to a first embodiment of the present invention. This is an example of an indoor cordless telephone, where 1 is a mobile terminal (MT),
Reference numeral 2 indicates a fixed machine (BT: Base Terminal). In this system, an upstream signal from the mobile device 1 is transmitted to the fixed device 2 via radio waves and further connected to the wire network 20. Further, the down signal is configured to be transmitted from the fixed device 2 to the mobile device 1 by utilizing the means of spatial light transmission. The detailed techniques of the optical receiver and the wireless transmitter of the mobile device 1 and the optical transmitter and the wireless receiver of the stationary device 2 are well known and therefore omitted.

By adopting such a transmission system, the mobile device 1 can be reduced in size, weight, power consumption, and cost. That is, since the receiving system is an optical receiver, it can be directly detected and can be handled as a baseband signal, so circuit integration and power saving are much easier than wireless systems, and the transmitting system uses wireless. As a result, it becomes possible to transmit indoors with a small amount of electric power as compared with light. Also, as a circuit, the transmission system can be easily made into a one-chip IC and the filter can be simplified, so that there is little problem in terms of cost. In addition, since different propagation paths are used, transmission and reception can be separated very easily, a transmitting / receiving demultiplexer is not required, and there is almost no interference between transmitting and receiving. However, the fixed machine 2 requires a high output and an omnidirectional light emitting source, and since the wireless system (reception system) is almost the same as the conventional one, considering only the fixed machine 2 is disadvantageous in cost. Considering that a large number of mobile units 1 can be accommodated because the transmission system is multi-channel access, the cost can be sufficiently reduced as a total system.

 FIG. 2 shows a second embodiment of the present invention.

Like a wooden house, radio waves can propagate between rooms and transmit signals, but light cannot propagate when there are obstacles such as thinning, and the uplink and downlink circuit qualities are extremely different. In such a case, as shown in FIG. 2, only the optical transmission section 3 is branched from the fixed machine 1 and provided as a branch of the fixed machine 2, so that the communication in the two zones A and B can be covered.

FIG. 3 is an example of a cordless communication system used in an office or the like in the third embodiment of the present invention. 1 in the figure
Is a mobile station, 2 is a fixed station (BT), 4 is a radio network controller (RCU), and 5 is a private branch exchange (PBX). In this case, the transmission zone is provided for each room, and each has a fixed machine (BT) 2a,
… 2x is installed and can be connected to a wired network. The RCU 4 has a position registration function and provides a system that enables communication anywhere as long as the mobile device 1 moves to any zone as long as the position registration is possible. At this time, if the position registration is performed by an optical transmission system, there is no overreach between zones in radio waves, so that the position registration can be performed accurately.

FIG. 4 shows a fourth embodiment of the present invention. In the figure,
1 is a mobile device, 2 is a fixed device, 6 is a personal computer, 7 is a TV, and 8 is an AV (audio visual) device.

In this case, send information from the mobile device 1 to the personal computer 6,
The mobile device 1 controls the TV 7 and the AV device 8. Data is transmitted from the mobile device 1 to the stationary device 2 by radio waves and from the stationary device 2 to each terminal 6, 7, 8 by light. .
Therefore, the stationary device 2 has the function of a transponder that receives radio waves and sends them out as light.

By adopting such a system, it becomes possible to perform data transmission between a mobile terminal (mobile device) and an information processing device such as a stationary personal computer, and remote control of many devices can be performed by one remote control. It becomes possible to do it with a functional mobile device.

As described above, the present invention performs downlink transmission from a fixed device to a mobile device by optical space transmission, and adopts a transmission method by radio waves for uplink transmission from the mobile device to the fixed device.
Achieved drastic downsizing and power saving of mobile terminal devices,
In addition, it reduces interference between transmission and reception, facilitates separation, and simplifies the circuit and realizes IC, and its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is a conceptual diagram illustrating a first embodiment of a transmission mobile communication system of the present invention, FIG. 2 is a conceptual diagram showing a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. 4 is a conceptual diagram showing a fourth embodiment of the present invention, and FIG. 5 is a conceptual diagram showing an example of conventional indoor mobile communication (cordless telephone). 1 ... mobile unit, 2 ... fixed unit, 3 ... fixed unit having only transmission function, 4 ... wireless line controller, 5 ... private converter, 6 ... personal computer, 7 ... TV, 8 ......
AV (audio / visual) device.

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Claims (2)

(57) [Claims] 1. A fixed device and a mobile device which is a portable mobile terminal device, wherein optical transmission is used for a downlink from the fixed device to the mobile device, and an uplink from the mobile device to the fixed device. In a transmission mobile communication system that uses radio wave transmission, a second fixed machine having a downlink optical transmission function is provided in a zone that transmits radio waves but does not propagate light between the first fixed stations. A transmission mobile communication system provided by branching from the first fixed machine. 2. An information processing apparatus such as a personal computer existing in a room, which receives a signal from a mobile device by radio waves and converts the signal as it is or after performing some processing, to an optical signal. A transmission mobile communication system comprising a fixed machine for transmitting data and transmitting a remote control signal for TV, audio, video equipment and the like.