JP2002084234A - Optical wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple optical wireless communication system where a wireless mobile station put in a bag or a pocket can receive an incoming call while minimizing the use of a radio wave. SOLUTION: A base station has radio wave transmission/reception sections (11a, 11b) for each of optical wave transmission/reception sections (8a, 8b) and the radio wave transmission/reception sections simultaneously transmit a calling radio wave on which wireless mobile station identification code information is superimposed. After calling, the communication between the base station and a mobile station is made by light via the optical wave transmission/ reception sections.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical radio communication system using light waves as a communication medium between a radio base station and a radio mobile station, and radio waves as a medium for a signal calling the radio mobile station.

The present invention is suitable for a radio communication system for use in a limited area such as a station building or a floor, particularly in a hospital or the like, and uses radio waves only for calling mobile stations.
Light waves are used for subsequent communication between the mobile station and the base station.

[0003]

2. Description of the Related Art In recent years, wireless mobile communication such as a personal handy phone system (PHS) and a portable telephone system has been rapidly increasing. While these wireless mobile communication systems have the convenience of being able to communicate anywhere by carrying a wireless mobile station, on the other hand, medical radio equipment malfunctions due to radio waves emitted by the wireless mobile station.

As a means for solving the above problem, an "optical wireless communication system" (JP-A-2000-49709) has been proposed.

This will be described with reference to FIG.

FIG. 2 is a configuration diagram of a conventional optical wireless communication system, wherein reference numerals 1a, 1b, and 1c denote wireless mobile stations, 2a, and 2a.
b, 2c are the lightwave transmitting / receiving units of the wireless mobile stations 1a, 1b, 1c, respectively, and 3a, 3b, 3c are the wireless mobile stations 1 respectively.
a, 1b, and 1c pager units, 4 is a pager base station, 5 is a pager calling radio wave from the pager base station 4, 6 is a public network, 7 is a wireless base station, and 8a and 8b are lightwave transmission and reception of the wireless base station 7, respectively. Unit 9 is a lightwave transmitting / receiving unit 8
a and the interlink lightwave between the lightwave transmitting and receiving unit 2a.

The light wave transmitting / receiving units 8a and 8b
In the wireless communication cover area.

When there is an incoming call at the radio mobile station 1a, the radio base station 7 sends a paging signal of the pager section 1a to the pager base station 4 via the public network 6, and the pager base station 4 transmits a pager paging radio wave 5. I do. When receiving the pager calling radio wave 5, the pager units 3a, 3b and 3c use the pager function to operate the pager unit 3a.
Sounds. The user of the wireless mobile station 1a notified of the incoming call by this ringing moves the lightwave transmission / reception unit 2a to one of the transmission / reception ranges of the lightwave transmission / reception units 8a and 8b, and establishes a mutual link by the mutual link lightwave 9. The radio mobile station 1a with which the mutual link has been established makes the main ring, and the user confirming the main ring goes off-hook to the radio mobile station 1a to start communication.

[0009]

In a conventional optical wireless communication system, a pager is used to call a wireless mobile station. Therefore, it is necessary to construct an interconnection system between the optical wireless communication system and the pager system, and the configuration of the apparatus becomes complicated, which is inconvenient.

As a means for solving this problem, an optical wireless communication system using only a light wave without using a pager at all can be considered. In this method, a wireless mobile station is put in a bag, a pocket, or the like. In such a case, there is a problem that the wireless mobile station cannot receive the call signal and cannot perform communication.

An object of the present invention is to provide an optical wireless communication system capable of receiving an incoming call even if the wireless mobile station is placed in a bag or a pocket while minimizing the use of radio waves in order to solve these problems. It is to provide by simple equipment.

[0012]

A feature of the present invention to achieve the above object is an optical wireless communication system for performing bidirectional communication using light between a wireless base station and a wireless mobile station. The base station carries at least one lightwave transmission / reception unit for performing bidirectional communication with light with the radio mobile station, and carries identification code information of the radio mobile station provided for each lightwave transmission / reception unit. A radio wave transmitting unit for transmitting a calling radio wave, wherein a plurality of the light wave transmitting and receiving units are dispersed in the coverage area of the radio base station, and all radio waves are transmitted when the base station transmits the calling radio wave. A transmitting unit simultaneously transmits radio waves, the radio mobile station transmits a lightwave transmitting / receiving unit for communication using light with the base station, and identification code information from the radiowave transmitting unit of the base station. A light having a discriminating unit In the communication system.

The main feature of the present invention is that the base station has a function of transmitting a paging radio wave carrying radio mobile station identification code information as paging means of the radio mobile station. or,
Another feature of the present invention is that a pager base station is not required.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described using a PHS as an example.

FIG. 1 is a block diagram of an optical wireless communication system according to the present invention.
a, 2b, and 2c are wireless mobile stations 1a, 1b, and 1c, respectively.
7 is a radio base station, 8a and 8b are lightwave transmission and reception units of the radio base station 7, 9 is a cross link lightwave between the lightwave transmission and reception unit 8a and the lightwave transmission and reception unit 2a, 10a, 10b, and 10
c is a radio mobile station identification code information discriminating unit of the radio mobile stations 1a, 1b and 1c, 11a and 11b are radio wave transmission units of the radio base station 7, and 12 is radio mobile station identification code information from the radio transmission units 11a and 11b. Is a paging radio wave for a mobile station.

A plurality of lightwave transmitting / receiving sections 8a and 8b and a plurality of radio wave transmitting sections 11a and 11b of the radio base station 7 are dispersedly provided in a radio communication cover area of the radio base station 7.

A pulse signal wave, a continuous wave (sine wave) or a weak radio wave can be used as the radio mobile station calling radio wave 12 carrying the radio mobile station identification code information.

In the case of a pulse signal wave, information is transmitted by intermittently transmitting an electromagnetic wave in the form of a pulse and making the pulse transmission interval variable. The shorter the use time of the electromagnetic wave, the smaller the effect on medical equipment and the like. By using this pulse signal wave, the total time during which the electromagnetic wave is transmitted can be minimized, and the possibility of affecting medical devices and the like can be reduced.

In the case of a sine wave, an electromagnetic wave of a sine wave is intermittently transmitted, and this (1) off time, (2) on time, or (3) both off time and on time are made variable. By sending information. Alternatively, information is transmitted by applying a weak FM modulation to an electromagnetic wave of a sine wave. The smaller the high-frequency component contained in the electromagnetic wave transmitting information, the smaller the effect on medical equipment and the like. By using a sine wave, high-frequency components contained in radio waves can be reduced as much as possible, and the possibility of affecting medical devices and the like can be reduced.

Weak radio waves are defined in Article 6 of the Ordinance for Enforcement of the Radio Law.
It is a radio wave having an electric field strength of 35 dBμV / m or less at a distance of m. This is the unnecessary radio wave allowable value class A50dBμ of electronic information equipment specified by the standard such as VCCI.
V / m (30 MHz to 230 MHz) or 57 dBμV
/ M (230 MHz to 1 GHz). Therefore, the electromagnetic interference caused by the incoming signal wave due to the weak radio wave does not pose a problem as an electromagnetic interference source. In a frequency band of less than 322 MHz, the electric field strength at a point 3 m away from the above-mentioned area is 50%.
It is a radio wave of 0 dBμV / m or less. In order to reduce the influence on medical equipment and the like, the weaker the radio wave to be used, the more secure the radio wave. In the case of a weak radio wave, the modulation method based on the information is arbitrary, and any method other than the above-described pulse signal wave, on / off wave, and FM modulation can be used.

When there is an incoming call at the radio mobile station 1a, radio radio station calling radio waves 12 carrying radio mobile station identification code information are simultaneously transmitted from the radio transmission units 11a and 11b of the radio base station 7. When the radio mobile stations 1a, 1b and 1c receive the radio mobile station calling radio wave 12, the radio mobile station identification code information discriminating sections 10a, 10b and 10c discriminate the radio mobile station identification code information, and the radio mobile station has The radio mobile station 1a having the unique code and the radio mobile station identification code information that tentatively rings, and the non-matching radio mobile stations 1b and 1c do not tentatively ring. The user of the wireless mobile station 1a notified of the incoming call by the provisional ringing moves the lightwave transmission / reception unit 2a to one of the transmission / reception ranges of the lightwave transmission / reception units 8a and 8b, and establishes a mutual link by the mutual link lightwave 9. The radio mobile station 1a with which the mutual link has been established makes the main ring, and the user confirming the main ring goes off-hook to the radio mobile station 1a to start communication.

[0022]

As described above, by using the calling radio wave carrying the radio mobile station identification code information for calling the radio mobile station of the optical radio communication system using the light wave as the communication medium, the radio wave can be provided by simple equipment. Even when the mobile station is in a bag or pocket, it can be called. Further, the present invention can minimize the effect on medical equipment and the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical wireless communication system of the present invention.

FIG. 2 is a configuration diagram of a conventional optical wireless communication system.

[Explanation of symbols]

1a, 1b, 1c Radio mobile stations 2a, 2b, 2c Radio mobile stations 1a, 1b, 1c
c lightwave transmitting and receiving units 3a, 3b, 3c
c pager section 4 pager base station 5 pager calling radio wave from pager base station 4 6 public network 7 wireless base stations 8a and 8b lightwave transmitting / receiving section of wireless base station 7 9 mutual transmission between lightwave transmitting / receiving section 8a and lightwave transmitting / receiving section 2a Link light waves 10a, 10b, 10c Radio mobile stations 1a, 1
b, 1c wireless mobile station identification code information discriminator 11a, 11b Radio transmitter 12 of radio base station 7 Radio mobile station calling radio wave carrying radio mobile station identification code information by pulse signal waves from radio transmitters 11a, 11b

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Ito 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-Term in Nippon Telegraph and Telephone Corporation (reference) 5K002 DA04 DA05 FA03 GA05 GA07 5K033 AA03 AA04 DA02 DA17 5K067 AA06 BB04 BB22 CC14 DD13 DD17 EE02 EE10 EE35 EE37

Claims (6)

[Claims] 1. An optical wireless communication system for performing communication bidirectionally using light between a wireless base station and a wireless mobile station, wherein the wireless base station bidirectionally communicates light with the wireless mobile station. At least one lightwave transmitting and receiving unit for performing communication using the lightwave transmitting and receiving unit, and a radio wave transmitting unit that is provided for each of the lightwave transmitting and receiving units and transmits a calling wave carrying identification code information of the wireless mobile station. The plurality of units are distributed and provided in the coverage area of the wireless base station, and when the base station emits a calling radio wave, all the radio wave transmitting units simultaneously transmit a radio wave, and the wireless mobile station includes: An optical wireless communication system, comprising: a lightwave transmission / reception unit for communication with a base station using light; and a determination unit for determining identification code information from the radio wave transmission unit of the base station. . 2. The calling radio wave is a pulse signal wave that is intermittently pulsed, and is a pulse signal wave on which identification code information is mounted by changing a pulse transmission interval.
The optical wireless communication system according to claim 1. 3. The optical wireless communication system according to claim 1, wherein the calling radio wave is a sine wave, and identification code information is loaded by making at least one of an on time and an off time variable. 4. The optical wireless communication system according to claim 1, wherein the calling radio wave is a sine wave, and identification code information is mounted by FM modulation. 5. The calling radio wave is a weak radio wave,
The optical wireless communication system according to claim 1. 6. The paging radio wave is at least 322 MHz and the electric field strength at a point 3 m away from the base station is 35
The optical wireless communication system according to claim 5, wherein the optical wireless communication system is not more than dBμV / m.