JPH02193425A - Mobile communication system - Google Patents

Abstract

PURPOSE:To form the mobile communication system which uses a microzone in cities and a small zone in suburbs by allowing an on-vehicle repeater and a portable terminal to receive a control signal sent from a radio base station over the same radio channel with the on-vehicle repeater and portable terminal are at least in the small zone. CONSTITUTION:The portable terminal 14 in the microzone 3 makes a direct communication with a microzone radio base station 13. Then the signal that the portable terminal 23 in the small zone 5 sends to a small-zone radio base station 22 is sent through the on-vehicle repeater 24. When the base station 22 sends a control signal to the portable terminal 23 and on-vehicle repeater 24, the signal is sent by using a radio channel f1. The portable terminal 23 and on-vehicle repeater 24 receives the control signal and perform necessary operation. Further, when the portable terminal 23 sends the signal to the base station 22, the terminal sends the signal to the on-vehicle repeater 24 by using the radio channel f2. Once receiving this signal, the on-vehicle repeater 24 sends the signal which is received from the portable terminal 23 to the base station 22 by using a radio channel f3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mobile communication system using a zone system, and in particular, in urban areas, the service area is covered by micro zones, and in the suburbs, the service area is covered by small zones. related to mobile communication systems.

[Conventional technology]

Conventional mobile communication systems have been improved in various ways, primarily with the problem of how to handle a large number of calls within a limited frequency band. As a result, a small zone system car telephone system called a cellular one-way system has now been put into practical use. However, this small zone system car phone system has shown remarkable growth since its launch, and many countries around the world are complaining of a shortage of frequencies. This trend is particularly noticeable in urban areas where traffic is concentrated. For example, when looking at the distribution of car phone traffic in Tokyo, a heavy concentration of traffic is observed in Chiyoda Ward and Aoshiro. For this reason, it takes three to four times the normal time (20 to 30 seconds) from the time a call is made to the time the call is received. This is due to a lack of call channels, and to address this, telecommunications carriers are subdividing zones within the Tokyo area to increase subscriber capacity. These circumstances are detailed in Nikkei Electronics No. 401, pages 91 to 104.

Furthermore, as a new trend in car telephone systems, the introduction of mobile terminals that can be carried by subscribers has been realized. Since such mobile terminals are strongly required to be small and lightweight, the transmission power of the radio cannot be increased very much. For this reason, zone subdivision, that is, microzonation, is also required from this point of view. Therefore, in future mobile communication systems, at least in urban areas where the number of subscribers is large, a micro zone system with an extremely small zone radius will be required.

However, in this microzone system, the number of wireless base stations increases significantly, resulting in an increase in system cost. In urban areas where the number of subscribers is large, the system cost may be slightly higher, but in suburban areas where the number of subscribers is not so large, such a micro-zone system is not economically viable, so the current small-zone system is used to provide services. will continue.

In other words, by using a system that uses both micro zones in urban areas and small zones in suburban areas,
An efficient system can be constructed for service areas where the areal density of subscribers varies.

[Problem to be solved by the invention]

In the conventional mobile communication system described above, when a micro zone and a small zone are used together and a mobile terminal is introduced, the transmission distance between the mobile terminal and the wireless base station within the micro zone area is limited for the mobile terminal with low transmission power. However, in a small zone area in the suburbs, the zone area is large and the transmission distance between the mobile device and the wireless base station may be long, so if the mobile device is located within the small zone area, Service is only available in extremely limited areas, that is, near wireless base stations. Therefore, in order to solve the problem of low transmission power of mobile terminals in small zone areas, it is necessary to provide a vehicle-mounted repeater that relays and amplifies the signal from the mobile terminal and transmits it to the wireless base station.

However, if the in-vehicle repeater relays the signal received from the wireless base station to the mobile terminal, the in-vehicle repeater must also have a transmission function to transmit the signal received from the wireless base station to the mobile terminal. Yes, the cost will be high. In addition, if multiple in-vehicle repeaters transmit received signals from a wireless base station to a mobile terminal using the same wireless channel, even if there is no interference between the wireless base station and the in-vehicle repeater, the in-vehicle repeater and the mobile terminal There will be interference between them.

Furthermore, if the wireless base station sends signals to the in-vehicle repeater or mobile terminal on separate radio channels, the wireless base station must be aware of the difference between the in-vehicle repeater and the mobile terminal when transmitting signals. There is also the problem of not being able to do so.

An object of the present invention is to provide a mobile communication system that solves the above-mentioned problems when providing services within a small zone.

[Means to solve the problem]

The present invention provides a mobile communication system that includes at least a wireless base station that covers a service area where traffic is concentrated in a micro zone and a service area where traffic is not concentrated in a small zone, an on-vehicle repeater, and a mobile terminal. , within the small zone, the in-vehicle repeater is a mobile communication system that, when receiving a signal from the mobile terminal, amplifies the received signal and transmits it to a wireless base station, the in-vehicle repeater and the mobile terminal The vehicle-mounted repeater and the mobile terminal receive control signals transmitted from the wireless base station using the same wireless channel while the mobile terminal is located within at least a small zone.

[Effect]

As mentioned above, in a system that uses both a micro zone and a small zone, in order to accommodate mobile terminals with low transmission power, the zone area must be wide and the transmission distance between the mobile terminal and the wireless base station must be long. In small zones with high traffic density, it is necessary to install a repeater in the car and use a mobile communication system that can provide service if the subscriber's movement range is within a certain distance from the car.

In the present invention, while the in-vehicle repeater and the mobile terminal are located within at least a small zone, the in-vehicle repeater and the mobile terminal receive control signals transmitted from the wireless base station using the same radio channel. By doing this, the in-vehicle repeater and mobile terminal can receive commands instructed from the wireless base station almost simultaneously, so the in-vehicle repeater and mobile terminal can synchronize and receive commands instructed from the wireless base station. can be executed.

By doing so, it is possible to provide a high-quality service that allows mobile terminals to communicate with the wireless base station anywhere within the small zone area as long as it is within a certain distance from the vehicle.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an example of the use of wireless channels in the present invention, and FIG. 2 is a block diagram showing an example of a mobile communication system to which the present invention is applied.

This mobile communication system is configured as follows. Microzone 1. 2. Micro zone wireless base stations 11, 12, and 13 are installed in small zone 4, respectively.
, 5 are provided with small zone wireless base stations 21 and 22. Reference numeral 14.23 indicates a mobile device, reference numeral 15
．． Reference numeral 25 indicates a vehicle-mounted terminal, and reference numeral 24 indicates a vehicle-mounted repeater.

In the mobile communication system as described above, the in-vehicle terminal 15 existing in the micro zone 1 directly communicates with the micro zone wireless base station 11, and the in-vehicle terminal 25 existing in the small zone 4 directly communicates with the small zone wireless base station 21. . Also,
A mobile terminal 14 existing within the micro zone 3 directly communicates with the micro zone wireless base station 13. however,
Unlike the mobile terminal 14, the mobile terminal 23 exists within the small zone 5, so the in-vehicle repeater 24 and the mobile terminal 23 directly receive the control signal transmitted by the small zone wireless base station 22 using the same radio channel. , the signal transmitted from the mobile terminal 23 to the small zone wireless base station 22 is sent via the on-vehicle repeater 24.

When the small zone wireless base station 22 transmits a control signal to the mobile terminal 23, the in-vehicle repeater 24, or both the mobile terminal 23 and the in-vehicle repeater 24, the small zone wireless base station 22 uses the wireless channel f1. Send control signals.

The mobile terminal 23 and the vehicle-mounted repeater 24 each receive a control signal transmitted from the wireless base station 22 using the wireless channel fl, and execute operations as necessary.

Furthermore, when the mobile terminal 23 transmits a signal to the small zone wireless base station 22, the mobile terminal 23 transmits the signal to the vehicle-mounted repeater 24 using the wireless channel r2. When the in-vehicle relay 824 receives the signal from the wireless channel f2, it transmits the signal received from the mobile terminal 23 to the small zone wireless base station 22 using the wireless channel f3.

〔Effect of the invention〕

As described in detail above, according to the present invention, the in-vehicle repeater and the mobile terminal receive control signals transmitted from the wireless base station using the same wireless channel.

For this reason, the in-vehicle repeater and mobile terminal can each perform operations according to their needs, so the wireless base station is aware of the control signal sent to the in-vehicle repeater or the control signal sent to the mobile terminal. There's no need. In other words, the communication procedure when a wireless base station is installed in a small zone can be the same as the communication procedure when a wireless base station is installed in a microzone, so in urban areas, microzones can be used to This has the advantage that a mobile communication system using small zones can be easily provided.

[Brief explanation of the drawing]

FIG. 1 is a sequence diagram showing an example of the use of wireless channels in the present invention, and FIG. 2 is a configuration diagram showing an example of a mobile communication system to which the present invention is applied. 1, 2. 3...Micro zone 4.5...Small zone 11, 12.13...Micro zone wireless base station 14
, 23...Mobile terminals 15, 25...In-vehicle terminals 21, 22...Small zone wireless base station 24...
・・・Vehicle repeater

Claims (1)

[Claims] (1) In a mobile communication system consisting of at least a wireless base station that covers a service area where traffic is concentrated in a micro zone and a service area where traffic is not concentrated in a small zone, an in-vehicle repeater, and a mobile terminal, Within the small zone, the vehicle-mounted repeater:
When a signal is received from the mobile terminal, the received signal is amplified and transmitted to a wireless base station. A mobile communication system characterized in that the repeater and the mobile terminal receive control signals transmitted from the wireless base station using the same wireless channel.