JPH0479619A - Communication control method for mobile communication system - Google Patents

Abstract

PURPOSE:To realize a wide mobile communication network with a small number of fixed stations by making the fixed stations to transmit reception packets in a short-wave frequency range having a possibility of reaching an aimed mobile station in order of fixed stations having higher possibilities of reaching the aimed mobile station. CONSTITUTION:Upon starting communication with a mobile station 3n, a mobile station 3a puts information including its own identification code, the identification code of the aimed station 3n, and the content to be transmitted in a packet and transmits the packet by using one or plural frequencies in a previously designated short-wave band which is expected to be received by many stations of fixed stations 1a-1n. Each fixed station 1a-1n, upon receiving the packet from the station 3a, sends the decoded result of the packet to a switching exchange 4 which transmits the decoded result received by the fixed station having the best radio channel quality to all other fixed stations through a connected network At the time of the transmission, the decoded result is successively transmitted to the fixed stations in order of, for example, the possibility of being received by the aimed mobile station on the basis of the information regarding the mobile station.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a communication control method in a mobile communication system for vehicles, ships, aircraft, etc.

(Prior art) In mobile radio systems, the service area is divided into zones (wireless zones), and each zone is provided with a base station that is a fixed transmitting/receiving station, and each base station is located within its own wireless zone. The base station sends and receives various signals to and from the mobile station, which is a mobile transmitting and receiving station, and monitors the quality of the wireless line for switching wireless lines.The base station controls and commands the wireless line, manages the wireless quality, and , connected to the switching center via a radio network control station that monitors and controls the base station,
A configuration is adopted in which this switching center connects to the general telephone network and connects mobile stations to each other. In such mobile radio systems, mobile stations are able to talk and communicate with telephone network subscriber telephones and other mobile stations via base stations that serve the zone in which they are located. Examples include car phones, ship phones, train public phones, and mobile phones.

By the way, conventional systems of this type require a large number of base stations to service a wide area, which increases system cost and requires maintenance.

(Problem to be Solved by the Invention) In this way, in a mobile radio system, a mobile station can make calls to a subscriber telephone of the telephone network or another mobile station via a base station that serves the zone in which the mobile station is located. Communication is now possible. However, in conventional systems of this type, it is necessary to install a large number of wireless zones in order to be able to service a wide area, and each wireless zone requires a base station, which increases system costs and increases costs. However, there is a problem that maintenance is difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a communication control method for a mobile communication system that can cover a wide area and reduce system costs and maintenance. be.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention is carried out as follows. In other words, multiple wireless zones are provided, and each wireless zone is provided with a fixed transceiver station that serves as a base station.The fixed transceiver station and the mobile transceiver station exchange information by wireless communication, and each fixed transceiver station communicates with each other. In addition to being connected via a network, each fixed transmitting/receiving station uses multiple shortwave bands to send and receive communication information with a mobile transmitting/receiving station. Forming information including each piece of content information into a packet format,
This is transmitted at one or more predetermined frequencies in the optimal shortwave band that takes into account the current radio wave propagation situation, and the fixed transceiver station receives it and transmits it to each of the fixed transceiver stations. The fixed transmitting/receiving station uses a shortwave band that has a high probability of reaching the destination mobile transmitting/receiving station, and sequentially transmits the packet from each fixed transmitting/receiving station until there is a reception response from the destination mobile transmitting/receiving station within a predetermined number of times. It is characterized by transmitting in the form of a packet, and when there is a reception response, communication is carried out in the form of a packet through the station used for transmission and reception. Second, the packets transmitted from the mobile station have information including the identification codes of the own station and the other mobile station, communication contents, and the approximate locations of the own station and the other mobile station, and the fixed station that receives the packet The present invention is characterized in that, based on the approximate position information of the mobile station to which the packet is to be transmitted, which is included in the packet, control is performed so that the packet is transmitted in order from the fixed station that is most likely to receive the packet at that position.

(Function) The system of the present invention as described above is composed of a plurality of fixed shortwave receiving stations (fixed stations) and a plurality of mobile stations that are distributed over a wide area and connected by a wired communication network or a microwave multiplexed line network. The frequency used for communication is the shortwave band.

In the present invention, a mobile station transmits and receives information including the identification code of its own station and the other mobile station, and communication contents in a packet format, and the shortwave band is specified in consideration of the propagation situation between the fixed station group. The fixed stations exchange reception information with each other through the above-mentioned highly stable communication network, and transmit on one or more designated frequencies in the shortwave band that are likely to reach the destination mobile station. Moreover, the above-mentioned received packets are processed according to the season, time, etc. according to the best reception conditions, up to the specified number of times, until a reception response is received from the destination mobile station, starting from the fixed station that is most likely to reach the destination mobile station. Transmit in the shortwave band. Therefore, the mobile station can access a plurality of more distant fixed stations without necessarily accessing the geographically nearest fixed station, due to ionospheric reflections that are less affected by nearby topography and features.

In general, fixed stations can use high-gain transmitting/receiving antennas and high-power transmitters, and these are useful to complement the performance of mobile stations, which are limited by transmitting/receiving antennas and transmitting power. Because it is used, it is possible to transmit and receive radio waves over long distances.

Furthermore, in the present invention, the mobile station configures information including the identification codes of its own station and the other mobile station, communication contents, and the approximate positions of the own station and the other mobile station in a packet format.・Sends and receives short waves at the optimal frequency that is easily received by many stations according to conditions such as time of day, and the fixed station that receives the packet from this mobile station transmits this transmitted packet to all fixed stations. At the same time, each fixed station refers to the approximate location information of the other party and repeatedly transmits this packet a plurality of predetermined times, starting from the fixed station that is easiest to receive it, until a reception response is obtained.

In this way, packets from each station are transmitted using the shortwave band, and packets from mobile stations are transmitted in order from the fixed station that is easiest to receive by referring to the rough location information of the other party, so that the transmitted and received information is The possibility of reaching the other party's mobile station is extremely high, and since a short wave band is used, the area where transmission and reception can be performed is also extremely wide. Therefore, it is possible to cover a wide area with communication services using a small number of fixed stations.
In addition, by using the packet transmission method for sending and receiving information, it is possible to limit the amount of information generated by mobile stations, which reduces the line capacity of the communication network that connects fixed stations. By time-divisionally using a small number of shortwave band frequencies between mobile stations and fixed stations, frequency utilization efficiency can also be improved.

Therefore, according to this method, it is possible to obtain a wide coverage mobile communication network with a small number of fixed stations, and a mobile communication network can be realized with low system cost. It is possible to provide a communication control method for a mobile communication system that provides advantages such as ease of communication control.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of the present invention, in which 1a to 1n are base radio stations (base stations), which are fixed transmitting and receiving stations, respectively, 2a to 2n are base stations (fixed transmitting and receiving stations), and 2a to 2n are base stations (fixed transmitting and receiving station) wireless zone which is the service zone of 1a=in,
3a to 3n are mobile transceiver stations equipped with mobile radio equipment, 4 is a mobile radio exchange, and 5 is a switching network. Reference numeral 6 indicates a communication network having stable propagation characteristics, such as a wire such as an optical cable or a microwave multiplex line, which connects fixed transmitting/receiving stations (base radio stations).

Fixed transmitting/receiving stations (hereinafter referred to as fixed stations) la~In are basically mobile transmitting/receiving stations 3a~3m within the own wireless zone.
It is equipped with functions such as transmitting and receiving various signals with the terminal, and monitoring the quality of the radio line to control the switching of the radio line (shortwave frequency band) during a call to ensure good communication conditions.

In addition, mobile transmitting/receiving stations (hereinafter referred to as mobile stations) 3a to 31
In order to send and receive various signals to and from the fixed stations 1a-1n, which are base stations, and to maintain good communication conditions, the system performs radio line quality control to switch communication frequencies depending on the situation, and also performs radio line quality control in order to maintain good communication conditions. It has a function that allows the reception frequency to be switched in a time-division manner.

Multiple shortwave bands are assigned to each fixed station 1a-In, and mobile stations 3a to 3m that enter the wireless zone can communicate with the fixed station's radio using the shortwave band within the wireless zone. becomes. Furthermore, each of the fixed stations 1a-1n is connected to a switching network 5 via an exchange 4, so that calls can be made between the mobile stations 3a-3- or between the mobile stations and a regular telephone.

In this system, a plurality of shortwave frequencies are used as communication frequencies, and the mobile stations 3a to 3W on standby monitor reception while switching each frequency in a time-division manner. Each of the fixed stations 1a to 1n has a transmitting/receiving device whose transmitting/receiving frequency is each of a plurality of shortwave frequencies used in the system, and these transmitting/receiving devices are used to communicate with the mobile station. To avoid interference with each station, fixed stations 1a-1n and mobile stations 3a-
The communication information between the mobile stations 3m and 3m is in packet format, and this packet is sent to the mobile station 3n (n-1, 2, 3, . . .
), the content to be communicated, and the approximate locations of the own station and the other station. Furthermore, the mobile stations 3a to 3m continuously transmit packets containing error correction/detection codes a predetermined number of times.

The fixed stations 1a to 1n constantly receive signals at each shortwave frequency, and when receiving packets from the mobile stations 3a to 311, they perform error correction and detection at the time of decoding using error correction and detection codes included in the received packets. and transmits only correct received packets to other fixed stations. Each fixed station!
As mentioned above, each of the fixed stations a to 1n is configured to be able to exchange received packets with each fixed station via the existing communication network, and each of the fixed stations 1a to 1n receives packets transmitted from other fixed stations. When receiving a received packet, it has a function of wirelessly transmitting the received packet to its own service zone using an optimal number of shortwave frequencies used in the system.

In addition, the mobile stations 3a to 3m transmit information including identification codes of their own station and the called party's mobile station 3n, content to be communicated, approximate location information of their own station and the called party's station, error correction/detection code, etc. In addition to the function of forming the formed packet into a packet format, it is assumed that the formed packet can be received by more than one of the fixed stations 1a-1n if possible, taking into account the season, time, and topography around the own station at the time of communication. It has a function of transmitting in one or more pre-specified frequency bands of the predetermined shortwave bands. These functions can be achieved by equipping the communication device with a clock and calendar function, as well as a control circuit that sets the optimum frequency that can be selected in advance, taking into account the season, time of day, and topography around the transmitting location. For example, the transmission position and the other party's mobile station position information are determined by the user selecting and specifying the position information from a plurality of selectable position information on the mobile station side, and the mobile station transmits this information and clock and calendar function information. The system is configured to automatically select one or more shortwave frequencies that are most suitable for the season, time, and transmission location, and to transmit packets at these frequencies.

In addition, the mobile station in standby mode is capable of transmitting and receiving multiple shortwave frequencies used in the system, and one or more of these frequency bands is always selected depending on the season, time of day, and reception location. (It is also possible to divide it into two parts) and configure it for monitoring. At the mobile station, the receiving frequency is switched in a time-division manner so that it can receive packets no matter which frequency the packet is sent on.
Check the identification code of the other mobile station in the packet, and if there is an identification code of the own station, receive this packet, perform reception control to establish a reception system using this frequency, and perform predetermined reception response control. It is. Reception response control includes incoming call control at own station and fixed station (fixed transmitting/receiving station 1a).
-In) transmission control of response information.

Next, the operation of this system having such a configuration will be explained.

Among the mobile stations, a mobile station (hereinafter referred to as a calling mobile station) that attempts to make a call (hereinafter referred to as a calling mobile station) 3a inputs the identification codes of its own station and the called mobile station 3n, which is the called partner station, when starting communication with the other mobile station 3n. , information including the contents to be communicated and the approximate locations of the own station and the other station is formed into a packet format, and this is sent to the fixed stations 1a to 1 in consideration of the season, time, and topography around the own station.
The transmitter transmits using one or more frequencies in a pre-designated shortwave band that are expected to be received by as many stations as possible among n.

At this time, the transmitted packet is transmitted multiple times in succession at the fixed station in order to detect and correct errors in the received information, or it is transmitted with an error correction and detection code included, and this is transmitted on the receiving side. Process it so that it can be received without errors.

Each fixed station 1a = in constantly receives all pre-specified frequencies that may be transmitted by the mobile station 3a, and when receiving a packet from the mobile station 3a, if there is no error in the received data, the The results of decoding the received packets are sent to the exchange 4 along with the wireless line quality monitoring information, and the exchange 4 receives this information and concatenates the decoding results of the packets received by the fixed station with the best wireless line quality. It is transmitted to all other fixed stations through the communication network 6.

At this time, for example, based on the partner mobile station information, the decoding result is sent to the fixed station that is most likely to be received by the partner mobile station, and the fixed station transmits a packet based on the decoded information using a short wave band. If this station does not receive a reception response from the other mobile station even after repeating the transmission a predetermined number of times, the decoding result is sent to the next optimal fixed station and the same transmission as described above is performed. By doing so, it is possible to avoid the inconvenience of having multiple fixed stations call the other mobile station at the same time on the same frequency.

When a mobile station transmits a packet containing an error correction/detection code that is transmitted many times in succession, the fixed station 1a-In that receives this packet corrects the error during decoding using these error correction/detection codes. - Detects and transmits only correct received packets to other fixed stations.

In this way, the plurality of fixed stations 1a to 1n use the information on the approximate location of the partner mobile station 3n included in this received packet to determine the probability of reaching the location in consideration of the season and time. Using a predetermined frequency in a predetermined shortwave band, the received packet is transmitted a predetermined number of times from a fixed station that has a high probability of reaching the partner mobile station 3n.

The partner mobile station 3n always receives a pre-designated shortwave frequency that may be transmitted by a fixed station, and when it receives a packet containing its own identification code, it shifts to response control.
Sends a response signal indicating correct reception. The fixed station repeats the above transmission operation within a specified number of times until it receives this response signal, and if it still cannot receive the response signal, another fixed station takes over and causes the received packet to be transmitted a predetermined number of times.

In order to simplify the control, the mobile station 3a from the partner mobile station 3n
Transmission packets to the network are also processed in the same manner as described above.

However, in terms of efficiency, once mobile stations to communicate with each other are captured, it is better to use the captured fixed station to exchange packets, unless the communication condition deteriorates.

In this case, upon receiving a response signal indicating correct reception,
The receiving fixed station immediately notifies other fixed stations of the reception of the response signal, and connects the fixed station that received the packet from the calling mobile station with the fixed station that received the response signal from the other mobile station. A transmission/reception control system is established so that packets can be exchanged between the calling mobile station and the called mobile station.

Note that if a response signal cannot be obtained from the other mobile station, each fixed station will end the transmission operation after completing the specified number of transmission operations, and the calling mobile station will The fixed station that receives the packet performs control such as sending a connection failure sign to the calling mobile station and disconnecting the line.

As explained above, this system uses multiple frequencies in the shortwave band for communication between mobile stations and fixed stations, and when making a call, it selects the frequency that can transmit the farthest distance according to conditions such as the season and time of day. In addition to transmitting information such as outgoing calls, incoming call responses, and telephone calls, the transmitted information is structured into packets that include own station and other party identification codes, and error correction/detection codes, and the stationary station that received this transmitted packet The station checks this transmitted packet using an error correction/detection code, and if there is no error, forwards it to all fixed stations, and each fixed station sequentially receives this packet in a predetermined manner until a reception response is received. It is designed to be transmitted repeatedly multiple times, and is transmitted and received using a shortwave band and at the optimal frequency that can be received by a large number of fixed stations, depending on the conditions such as the season and time of day during communication. As a result, there is an extremely high possibility that the transmitted/received information will reach the partner mobile station, and since a short wave band is used, the area where transmission and reception can be performed is also extremely wide. Therefore, it is possible to cover a wide area with a small number of fixed stations, and
By using the packet transmission method for sending and receiving information,
Since it is possible to limit the amount of information generated by mobile stations, it is possible to reduce the bandwidth of the communication network that connects fixed stations.Moreover, it is possible to limit the amount of information generated by mobile stations and to reduce the bandwidth of the communication network that connects fixed stations. By using time division, frequency utilization efficiency can also be improved.

Therefore, according to this method, it is possible to obtain a mobile communication network that is covered by the law with a small number of fixed stations, and a mobile communication network can be realized at low system cost. In particular, a specific user can realize a private network for mobile communication in a legally covered area by using a relatively small number of fixed stations and a communication network connecting them.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope of the gist thereof. For example, in the above embodiments, the information in the packet may be Although we have shown an example of checking using an error correction/detection code, it is also possible to repeat the packet, send it a certain number of times, and have the receiving side accept the matching packet as the correct packet. Information may be omitted.

In addition, when a specific user realizes a private network for mobile communication in a legally covered area using a relatively small number of fixed stations and a communication network connecting these, fixed stations 1a to 1n, as shown in FIG. It consists of a reliable communication network 6 such as a wired or microwave multiplex communication network that connects these fixed stations 1a to 1n with each other, and mobile stations 3a to 3w similar to those described above. The fixed stations 1a to In are provided with the same. For example, the fixed stations 1a to 1In constantly receive signals on all pre-specified frequencies that may be transmitted by the mobile station, and when receiving a packet from the mobile station, the result of decoding the received packet and the wireless channel quality The monitoring information is sent to another fixed station, and the other fixed station receives this information and sends the decoding result of the received packet of the fixed station indicating the best radio link quality to all other fixed stations via the interconnection communication network 6. to a fixed station. At this time, for example, based on the partner mobile station information, the decoding result is sent to the fixed station that is most likely to be received by the partner mobile station, and the fixed station creates a packet based on the decoding information. The packet is transmitted using a shortwave band that is easy to use, and if a reception response is not obtained from the other mobile station even after repeating transmission a predetermined number of times, the decoding result is sent to the next optimal fixed station, and the same process as above is performed. It is good to have a function that allows the user to send the information. By configuring the fixed stations in this way, a relatively small number of fixed stations and a communication network connecting them can realize a mobile communication network that covers a wide range of areas at low cost, and covers a wide service area.
This is extremely effective when the number of mobile stations is small.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to obtain a legally covered mobile communication network with a small number of fixed stations, and a mobile communication network can be realized at a low system cost. Since the number of devices is small, it is possible to provide a communication control method for a mobile communication system that is easy to maintain and manage.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the invention, and FIG. 2 is a diagram for explaining another embodiment of the invention. 1a=1n...Fixed transmitting/receiving station (fixed station), 2a to 2n
...Wireless zone, 3a, ~3+a, 3n...Mobile transmitting/receiving station (mobile station)
, 4... Mobile radio exchange, 5... Switching network, 6...
・Stable communication network. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) Multiple wireless zones are provided, and each wireless zone is provided with a fixed transceiver station that serves as a base station.The fixed transceiver station and the mobile transceiver station exchange information by wireless communication, and each fixed transceiver station communicates with each other. In addition to connecting through communication networks,
Each fixed transmitting/receiving station uses multiple shortwave bands to transmit and receive communication information with a mobile transmitting/receiving station, and the mobile transmitting/receiving station contains identification codes of its own station and the communication partner's mobile station, as well as information on communication content. The information is formed into a packet format and sent to one of the most suitable shortwave bands considering the current radio wave propagation conditions.
It transmits on one or more frequencies specified in advance, and the fixed transceiver station receives it and transmits it to each fixed transceiver station, and each fixed transceiver station calculates the possibility of reaching the destination mobile transceiver station. Using a high shortwave band, each fixed transmitting/receiving station transmits the packet in turn up to a predetermined number of times until there is a reception response from the destination mobile transmitting/receiving station, and when there is a reception response, the station used for transmission/reception A communication control method for a mobile communication system, characterized in that communication is carried out by packets through a mobile communication system. (2) Packets transmitted from a mobile transmitting/receiving station have information including the identification codes of the own station and the other mobile transmitting/receiving station, communication contents, and the approximate positions of the own station and the other mobile transmitting/receiving station, and the fixed transmitting/receiving station that received the packet The present invention is characterized in that, based on the approximate location information of the mobile station to which the packet is to be transmitted, which is included in the packet, the packet is controlled to be transmitted in order from the fixed transmitting/receiving station that is easiest to receive at that location. A communication control method for a mobile communication system according to claim (1).