JP7384773B2 - Communication system, transmitting station, mobile station, communication method and computer program - Google Patents

Description

The present invention relates to a communication system, a transmitting station , a mobile station, a communication method, and a computer program.

BACKGROUND ART Conventionally, in order to ensure the reliability of communication, communication systems are known that include a working system and a backup system, and when communication becomes impossible in the working system, the system switches to the backup system to continue communication. For example, Patent Document 1 describes a wireless communication system in which a partner device that performs wireless communication with a working or standby wireless device determines whether system switching is necessary based on failure information received from the wireless device. has been done.

Furthermore, in Non-Patent Document 1, a handover method called "Multihomed Make-Before-Break" method is used to establish a link to another base station when it is confirmed that the communication quality of the link in use has deteriorated. A technique is described that performs handover processing when further deterioration in the communication quality of the link in use is confirmed.

Japanese Patent Application Publication No. 2014-147055

Mitsushiro Miya et al., “Realization of smooth handover system between different media using IEEE802.21”, Journal of Information Processing Society of Japan, Vol. 49, No. 1, pp. 335-349, January 2008.

However, in the technique of Patent Document 1 mentioned above, system switching is performed after a failure occurs in the wireless device, so there is a possibility that communication will be temporarily interrupted. Therefore, it is desirable to improve communication quality so as to prevent communication interruptions as much as possible.

In addition, although the technology in Non-Patent Document 1 mentioned above can theoretically reduce packet loss to zero during handover by establishing links with multiple base stations in advance, it is also possible to reduce local wireless communication quality. When handovers occur repeatedly due to fluctuations or deterioration, it is difficult to select an appropriate link at any time and perform handovers. When a communication terminal performs wireless communication while moving, a situation may occur in which local wireless communication quality fluctuates or deteriorates as the communication terminal moves. Therefore, it is desirable to adapt to local fluctuations or deterioration of wireless communication quality in communication terminals that perform wireless communication while moving.

The present invention has been made in consideration of such circumstances, and an object thereof is to improve communication between the transmitting station and the receiving station in a communication system in which at least one of the transmitting station and the receiving station is a mobile station. To be able to adapt to local fluctuations or deterioration of wireless communication quality in a mobile station when using a plurality of communication lines, and to improve communication quality so as to prevent communication interruptions as much as possible.

(1) One aspect of the present invention is a communication system including a transmitting station and a receiving station, in which at least one of the transmitting station and the receiving station is a mobile station, and the mobile station The transmitting station includes a communication quality prediction unit that predicts wireless communication quality on a first communication line with a receiving station, and the transmitting station includes a first transmitting unit that transmits data using the first communication line; a second transmitting unit that transmits data using a second communication line between a transmitting station and the receiving station; and a second transmitting unit that transmits data using a second communication line between the transmitting station and the receiving station; a transmission line selection unit that selects whether or not to perform data transmission using the second communication line by the second transmission unit; a second receiving section that receives data using the second communication line; quality of received data on the first communication line of the first receiving section ; and presence or absence of received data on the second communication line; a receiving line selection unit that selects which of the first communication line and the second communication line is to be used as a receiving line for receiving data from the transmitting station, based on It is a communication system.
(2) In one aspect of the present invention, when the transmitting station transmits data only through the first communication line and the predicted result of the wireless communication quality of the first communication line is deterioration, the transmitting station transmits data to the first communication line. In the case where data transmission using the second communication line is started in addition to data transmission on the first communication line, and data transmission is performed on both the first communication line and the second communication line, the first communication The communication system according to (1) above, wherein data transmission on the second communication line is terminated when a predicted result of wireless communication quality of the line is good, and data transmission is performed only on the first communication line.
( 3 ) One aspect of the present invention is that the transmission line selection unit starts data transmission using the second communication line when the predicted result of the wireless communication quality of the first communication line is poor; The communication system according to any one of (1) or (2) above, wherein data transmission using the second communication line is stopped when a predicted result of wireless communication quality of the first communication line is good.
( 4 ) In one aspect of the present invention, when the second communication line is a more stable line than the first communication line, the transmitting station and the receiving station transmit signals that require stable transmission. The communication system according to any one of (1) to (3) above always uses the second communication line .
( 5 ) In one aspect of the present invention, when the received data quality of the first communication line of the first receiving unit does not satisfy a predetermined received data quality standard, the receiving station may The communication system according to any one of (1) to ( 4 ) above requests the transmitting station to start data transmission using the second communication line when the data has not arrived at the second receiving unit.
( 6 ) One aspect of the present invention is that the communication quality prediction unit calculates an evaluation value of wireless communication quality based on the wireless quality measurement value of the first communication line, and the evaluation value is a predetermined wireless communication quality evaluation. If the standard is no longer satisfied, it is predicted that the wireless communication quality of the first communication line will deteriorate, and if the evaluation value satisfies a predetermined wireless communication quality evaluation standard, the wireless communication quality of the first communication line is good. The communication system according to any one of (1) to ( 5 ) above, which is predicted to be.
( 7 ) In one aspect of the present invention, the communication quality prediction unit acquires a distance between the mobile station and a base station of the first communication line to which the mobile station connects, and when the distance is a predetermined wireless The wireless communication quality of the first communication line is predicted to deteriorate when the communication quality evaluation standard is no longer satisfied, and the wireless communication quality of the first communication line is predicted to deteriorate when the distance satisfies the predetermined wireless communication quality evaluation standard. A communication system according to any one of (1) to ( 5 ) above, which is predicted to be good.
( 8 ) In one aspect of the present invention, the communication quality prediction unit is configured to use a communication quality map in which the wireless communication quality of a wireless communication network used for the first communication line is recorded for each point, and a scheduled travel of the mobile station. based on the route information, calculate the distance between the current location of the mobile station and a point on the planned travel route of the mobile station that does not satisfy a predetermined wireless communication quality evaluation standard, and the distance is within a predetermined threshold. If the distance exceeds a predetermined threshold, predict that the wireless communication quality of the first communication line is good; The communication system is any one of (1) to ( 5 ) above.
( 9 ) One aspect of the present invention is based on (1) above, wherein the received data quality is any one or more of the following: normal reception of data, packet loss rate, jitter, and image quality evaluation value of image data. ( 8 ) Any of the communication systems.

( 10 ) One aspect of the present invention is the transmitting station of a communication system in which at least one of a transmitting station and a receiving station is a mobile station, wherein a first communication line between the transmitting station and the receiving station is provided. a first transmitting unit that transmits data using a second communication line between the transmitting station and the receiving station; a second transmitting unit that transmits data using a second communication line between the transmitting station and the receiving station; a transmission line selection unit that selects whether or not the second transmission unit should perform data transmission using the second communication line based on a prediction result of wireless communication quality of the communication line, the transmission station , when data is being transmitted only through the first communication line and the predicted wireless communication quality of the first communication line is poor, the second communication is performed in addition to the data transmission through the first communication line. When data transmission using a line is started and data is being transmitted on both the first communication line and the second communication line, and the prediction result of the wireless communication quality of the first communication line is good; A transmitting station that terminates data transmission on the second communication line and transmits data only on the first communication line .

(11) In a mobile station, one aspect of the present invention includes a communication quality prediction unit that predicts wireless communication quality for a first communication line between the mobile station and a communication partner of the mobile station; Regarding a first transmitting unit that transmits data using a line, a second transmitting unit that transmits data using a second communication line between the mobile station and the communication partner, and the first communication line a transmission line selection unit that selects whether or not to perform data transmission using the second communication line by the second transmission unit based on a prediction result of wireless communication quality; a first receiving section that receives data; a second receiving section that receives data using the second communication line; and the quality of received data of the first communication line of the first receiving section and the second communication line. a receiving line selection unit that selects which of the first communication line and the second communication line is to be used as a receiving line for receiving data from the communication partner, based on the presence or absence of received data; This is a mobile station equipped with the following.

(12) One aspect of the present invention is a communication method for a communication system including a transmitting station and a receiving station, wherein at least one of the transmitting station and the receiving station is a mobile station, and the transmitting station a first transmission step of transmitting data using a first communication line between a station and the receiving station; and a communication quality prediction step of the mobile station predicting wireless communication quality for the first communication line. , whether or not the transmitting station performs data transmission using a second communication line between the transmitting station and the receiving station based on a prediction result of the wireless communication quality of the first communication line of the mobile station. a second transmission step in which the transmitting station performs data transmission using the second communication line based on the selection result of the transmission line selection step; and a second transmitting step in which the receiving station , a first receiving step in which the receiving station receives data using the first communication line; a second receiving step in which the receiving station receives data using the second communication line; Based on the received data quality of the first communication line and the presence or absence of the received data of the second communication line in the first receiving step, which communication line is selected between the first communication line and the second communication line, This communication method includes a receiving line selection step of selecting a receiving line to be used for receiving data from a transmitting station.

(13) In one aspect of the present invention, in a communication system in which at least one of a transmitting station and a receiving station is a mobile station, a first communication line between the transmitting station and the receiving station is connected to a computer of the transmitting station. a first transmitting step of transmitting data using a second communication line between the transmitting station and the receiving station; a second transmitting step of transmitting data using a second communication line between the transmitting station and the receiving station; a transmission line selection step of selecting whether or not to perform data transmission using the second communication line in the second transmission step, based on a prediction result of wireless communication quality of the communication line; The transmitting station transmits data on the first communication line when the predicted wireless communication quality of the first communication line is poor when data is transmitted only on the first communication line. In addition to transmission, data transmission using the second communication line is started, and when data transmission is performed on both the first communication line and the second communication line, the wireless communication quality of the first communication line is The computer program terminates data transmission on the second communication line when the prediction result is good, and performs data transmission only on the first communication line.

( 14 ) One aspect of the present invention includes a communication quality prediction step of causing a computer of a mobile station to predict a wireless communication quality for a first communication line between the mobile station and a communication partner of the mobile station; a first transmission step of transmitting data using one communication line, a second transmission step of transmitting data using a second communication line between the mobile station and the communication partner, and the first communication a transmission line selection step of selecting whether or not to perform data transmission using the second communication line in the second transmission step, based on a prediction result of wireless communication quality for the line; a first receiving step of receiving data using the second communication line; a second receiving step of receiving data using the second communication line; and a first receiving step of receiving data using the second communication line; A receiving line that selects which of the first communication line and the second communication line is to be used as a receiving line for receiving data from the communication partner, based on the presence or absence of received data on the communication line. A computer program for executing a selection step.

According to the present invention, in a communication system in which at least one of a transmitting station and a receiving station is a mobile station, when using a plurality of communication lines between the transmitting station and the receiving station, local It is possible to adapt to fluctuations or deterioration of wireless communication quality, and to improve communication quality so as to prevent communication interruptions as much as possible.

FIG. 1 is a block diagram illustrating a configuration example of a communication system according to a first embodiment. 2 is a flowchart illustrating an example of a procedure of transmission processing on a transmitting side (transmitting station) according to the first embodiment. 2 is a flowchart illustrating an example of a procedure of reception processing on a receiving side (receiving station) according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration example of a communication system according to a second embodiment. It is a block diagram showing an example of composition of a communications system concerning a 3rd embodiment.

Embodiments of the present invention will be described below with reference to the drawings.

[First embodiment]
FIG. 1 is a block diagram showing a configuration example of a communication system according to a first embodiment. In the communication system 1 according to the first embodiment shown in FIG. 1, communication is performed between a mobile station 100 and a fixed station 200. In the communication system 1, the mobile station 100 serves as a transmitting station and transmits data to a fixed station 200 (receiving station), and the mobile station 100 serves as a receiving station and receives data from the fixed station 200 (transmitting station). There are cases and cases.

In the communication system 1, for example, a mobile station 100, which is an autonomous vehicle, and a fixed station 200, which is a remote monitoring console, communicate with each other, and the autonomous vehicle is remotely monitored by the remote monitoring console. be. In this remote monitoring, stable communication between the mobile station 100 and the fixed station 200 is required because the behavior of the autonomous vehicle is constantly monitored.

Mobile station 100 includes a first communication terminal 101 , a second communication terminal 102 , a control section 103 , a line selection section 104 , and a communication quality prediction section 110 . Fixed station 200 includes a first communication terminal 201, a second communication terminal 202, a control section 203, and a line selection section 204.

(mobile station)
The mobile station 100 shown in FIG. 1 will be explained.

The first communication terminal 101 communicates using the first wireless communication network NW1. The first communication terminal 101 connects to a base station of the first wireless communication network NW1 and performs wireless communication with the base station. The first communication terminal 101 of the mobile station 100 establishes a communication line L1 with the first communication terminal 201 of the fixed station 200. Communication line L1 corresponds to the first communication line.

The second communication terminal 102 communicates using the second wireless communication network NW2. The second communication terminal 102 connects to a base station of the second wireless communication network NW2 and performs wireless communication with the base station. The second communication terminal 102 of the mobile station 100 establishes a communication line L2 with the second communication terminal 202 of the fixed station 200. Communication line L2 corresponds to the second communication line.

The communication line L1 is a communication line that is mainly used. The communication line L2 is a communication line used on a preliminary basis. The first wireless communication network NW1 used for the communication line L1 is, for example, a wireless communication network that is excellent in terms of communication performance and cost. On the other hand, since the communication line L2 is used on a preliminary basis, it is preferable that the second wireless communication network NW2 used for the communication line L2 has communication stability equal to or higher than that of the first wireless communication network NW1. For example, it is preferable that the second wireless communication network NW2 has a wider mobile communication area than the first wireless communication network NW1, or that communication interruptions are less likely to occur than the first wireless communication network NW1.

For example, when the first wireless communication network NW1 is a 5G (fifth generation mobile communication system) that has excellent communication performance, the second wireless communication network NW2 is an LTE (Long Term Evolution) system that has excellent communication stability. For example, when the first wireless communication network NW1 is a WiMAX system which is superior in terms of cost, the second wireless communication network NW2 is an LTE system which is superior in terms of communication stability. For example, in use at sea, when the first wireless communication network NW1 is an LTE system that is superior in terms of cost, the second wireless communication network NW2 is a satellite line system that is superior in terms of communication stability.

The first communication terminal 101 measures wireless communication quality when communicating using the first wireless communication network NW1. The wireless communication quality includes, for example, RSRP (Reference Signal Received Power), SINR (Signal to Interference and Noise power Ratio), and throughput. The first communication terminal 101 also acquires a base station identifier (base station ID) that identifies the base station of the first wireless communication network NW1 to which the terminal connects, and the current location (latitude and longitude) of the terminal. Further, the first communication terminal 101 measures the received data quality of data received from the first communication terminal 201 of the fixed station 200 via the communication line L1. The received data quality includes, for example, whether or not data is normally received, a packet loss rate, jitter, and an image quality evaluation value of image data.

The second communication terminal 102 determines whether data has arrived from the second communication terminal 202 of the fixed station 200 via the communication line L2.

The control unit 103 controls the mobile station 100. The control unit 103 controls the start and end of communication of the mobile station 100 according to instructions for starting and ending communication from the operator of the mobile station 100, the mobile station side system 10, and the like. The mobile station side system 10 is, for example, an automatic driving control system for an automatic driving car.

The control unit 103 transmits the transmission data received from the mobile station side system 10 to the fixed station 200 through at least one of the communication line L1 and the communication line L2. The communication line mainly used as a transmission line for transmitting data to the fixed station 200 is the communication line L1. When the control unit 103 receives the transmission line selection result from the line selection unit 104, it determines the transmission line for transmitting data to the fixed station 200 from the communication lines L1 and L2 based on the transmission line selection result.

Control unit 103 transmits the transmission line selection result received from line selection unit 104 to fixed station 200 through at least one of communication line L1 and communication line L2.

The control unit 103 transmits the received data received from the fixed station 200 to the mobile station side system 10. The communication line mainly used as a reception line for receiving data from the fixed station 200 is the communication line L1. When the control unit 103 receives the reception line selection result from the line selection unit 104, it determines the reception line for receiving data from the fixed station 200 from the communication lines L1 and L2 based on the reception line selection result.

Note that if data is normally received from the fixed station 200 only from one of the communication lines L1 and L2, the control unit 103 determines whether the data is received normally from the fixed station 200, regardless of the reception line selection result of the line selection unit 104. The communication line for receiving data is determined to be the receiving line for receiving data from the fixed station 200.

When the mobile station 100 transmits data to the fixed station 200, the control unit 103 adjusts the amount of data to be transmitted by changing the transmission bit rate etc. according to the performance of the first communication terminal 101 and the second communication terminal 102. It may also have a function.

The communication quality prediction unit 110 predicts the wireless communication quality of the communication line L1 between the mobile station 100 and the fixed station 200. In this wireless communication quality prediction, it is predicted that the wireless communication quality of the communication line L1 will deteriorate or be good in the future. Some examples of wireless communication quality prediction methods will be described below.

(Example 1 of wireless communication quality prediction method)
The communication quality prediction unit 110 predicts the wireless communication quality of the communication line L1 based on the measurement result of the wireless communication quality measured by the first communication terminal 101. The measurement result of the wireless communication quality of the first communication terminal 101 is the measurement result of the wireless communication quality when the first communication terminal 101 performs communication using the first wireless communication network NW1, and is the measurement result of the wireless communication quality of the communication line L1. Correspond to quality measurements. The measurement result of the wireless communication quality of the first communication terminal 101 is notified from the first communication terminal 101 to the communication quality prediction unit 110 via the control unit 103. The wireless communication quality is, for example, RSRP, SINR, throughput, etc.

The communication quality prediction unit 110 calculates a wireless communication quality score (evaluation value) using a predetermined score calculation method, for example, from the measurement results of RSRP and SINR. In this score calculation, RSRP and SINR may be weighted individually. The communication quality prediction unit 110 predicts that the future wireless communication quality of the communication line L1 will deteriorate when the wireless communication quality score no longer satisfies a predetermined score threshold (wireless communication quality evaluation standard). For example, if the wireless communication quality score changes from a good state in which it is above a predetermined score threshold for a certain period of time or more to a state in which the wireless communication quality score is lower than a predetermined score threshold for a certain period of time or more, future communication It may be predicted that the wireless communication quality of line L1 will deteriorate.

On the other hand, if the wireless communication quality score satisfies a predetermined score threshold, the communication quality prediction unit 110 predicts that the future wireless communication quality of the communication line L1 will be good. For example, if the wireless communication quality score exceeds a predetermined score threshold for a certain period of time or more, it may be predicted that the future wireless communication quality of the communication line L1 will be good.

(Example 2 of wireless communication quality prediction method)
The communication quality prediction unit 110 predicts the wireless communication quality of the communication line L1 based on the distance between the first communication terminal 101 and the base station of the first wireless communication network NW1 to which the first communication terminal 101 connects. . The communication quality prediction unit 110 acquires the position (latitude and longitude) of the base station of the first wireless communication network NW1 to which the first communication terminal 101 connects based on the base station ID of the base station. The base station ID of the base station of the first wireless communication network NW1 to which the first communication terminal 101 connects is notified from the first communication terminal 101 to the communication quality prediction unit 110 via the control unit 103. Further, the current position (latitude and longitude) of the first communication terminal 101 is notified from the first communication terminal 101 to the communication quality prediction unit 110 via the control unit 103.

The communication quality prediction unit 110 determines the current location (latitude and longitude) of the first communication terminal 101 based on the location (latitude and longitude) of the base station of the first wireless communication network NW1 to which the first communication terminal 101 connects, and the current location (latitude and longitude) of the first communication terminal 101. The distance between the base station and the first communication terminal 101 (terminal-to-base station distance) is calculated. The communication quality prediction unit 110 predicts that the future wireless communication quality of the communication line L1 will deteriorate when the distance between the terminal and the base station no longer satisfies a predetermined distance between the terminal and the base station threshold (wireless communication quality evaluation standard). do. For example, from a good condition in which the distance between the terminal and base station is below a predetermined terminal-to-base station distance threshold for a certain period of time or more, to a good state in which the distance between the terminal and base station is less than a predetermined terminal-to-base station distance threshold for a certain period of time or more, It may be predicted that the wireless communication quality of the communication line L1 will deteriorate in the future when the state changes to a state exceeding .

On the other hand, the communication quality prediction unit 110 predicts that the future wireless communication quality of the communication line L1 will be good if the distance between the terminal and the base station satisfies a predetermined distance threshold between the terminal and the base station. For example, if the distance between the terminal and the base station is less than a predetermined distance between the terminal and the base station for a certain period of time or more, it may be predicted that the wireless communication quality of the future communication line L1 will be good.

(Example 3 of wireless communication quality prediction method)
The communication quality prediction unit 110 predicts the wireless communication quality of the communication line L1 based on the record of the past wireless communication quality on the route that the mobile station 100 is scheduled to travel (planned travel route). The communication quality prediction unit 110 is based on the communication quality map in which the past wireless communication quality of the first wireless communication network NW1 used for the communication line L1 is recorded for each point and the planned travel route information of the mobile station 100. The distance between the current location of the mobile station 100 (for example, the current location (latitude and longitude) of the first communication terminal 101) and a point on the planned travel route of the mobile station 100 that does not satisfy a predetermined wireless communication quality evaluation standard ( Judgment target distance) is calculated. The planned travel route of mobile station 100 is set in advance in control unit 103. Regarding the communication quality map, for example, communication quality map data of an area including the planned travel route of the mobile station 100 is downloaded to the mobile station 100 in advance from a communication quality map storage server (not shown).

The communication quality prediction unit 110 predicts that the future wireless communication quality of the communication line L1 will deteriorate when the determination target distance no longer satisfies a predetermined determination target distance threshold (wireless communication quality evaluation standard). For example, from a good state where the determination target distance exceeds a predetermined determination target distance threshold (a state where the distance is far from a point that does not satisfy the wireless communication quality evaluation criteria), to a state where the determination target distance is below the predetermined determination target distance threshold ( It may be predicted that the future wireless communication quality of the communication line L1 will deteriorate if the wireless communication quality of the communication line L1 approaches a point where the wireless communication quality evaluation criteria are not satisfied.

On the other hand, when the determination target distance satisfies a predetermined determination target distance threshold, the communication quality prediction unit 110 predicts that the future wireless communication quality of the communication line L1 will be good. For example, if the determination target distance exceeds a predetermined determination target distance threshold, it may be predicted that the future wireless communication quality of the communication line L1 will be good. Note that if there is no point on the planned travel route of the mobile station 100 that does not meet the predetermined wireless communication quality evaluation criteria, the determination target distance is set to infinity "∞", so that the determination target distance does not meet the predetermined value. The result is that the distance exceeds the determination target distance threshold, and the future wireless communication quality of the communication line L1 is predicted to be good.

The above is an explanation of an example of the wireless communication quality prediction method. Note that the control unit 103 may acquire information such as the current position (latitude and longitude) of the mobile station 100 and the planned travel route from the mobile station side system 10.

The line selection unit 104 includes a transmission line selection function and a reception line selection function.

The transmission line selection function of the line selection unit 104 selects whether or not to perform data transmission using the communication line L2 by the second communication terminal 102 based on the prediction result of the wireless communication quality of the communication line L1 of the mobile station 100. do. The prediction result of the wireless communication quality of the communication line L1 of the mobile station 100 is notified from the communication quality prediction unit 110 to the line selection unit 104 via the control unit 103. The transmission line selection function of the line selection unit 104 notifies the control unit 103 of the transmission line selection result “start transmission on communication line L2” when the predicted result of the wireless communication quality of the communication line L1 is poor, and selects the communication line. In addition to the data transmission using L1, the control unit 103 starts data transmission using the communication line L2. On the other hand, when the prediction result of the wireless communication quality of the communication line L1 is good, the line selection unit 104 notifies the control unit 103 of the transmission line selection result "transmission completed on the communication line L2", and selects the communication line L2. The data transmission to be used is stopped by the control unit 103.

When the fixed station 200 requests to start data transmission using the communication line L2, the transmission line selection function of the line selection unit 104 sends the transmission line selection result “Start transmission on the communication line L2” to the control unit 103. The control unit 103 causes the control unit 103 to start data transmission using the communication line L2. A communication start request requesting to start data transmission using communication line L2 is received from fixed station 200 through either communication line L1 or L2 and sent to line selection unit 104 via control unit 103. Be notified.

The reception line selection function of the line selection unit 104 selects which of the communication lines L1 and L2 to select data from the fixed station 200 based on the quality of the received data on the communication line L1 of the first communication terminal 101. Select which line to use for reception. The received data quality includes, for example, whether or not data is normally received, a packet loss rate, jitter, and an image quality evaluation value of image data. The received data quality is notified from the first communication terminal 101 to the line selection section 104 via the control section 103.

The reception line selection function of the line selection unit 104 determines that the reception data quality of the communication line L1 is good when the reception data quality of the communication line L1 satisfies a predetermined reception data quality standard. The reception line selection function of the line selection unit 104 selects the communication line L1 as a reception line for receiving data from the fixed station 200 when the quality of received data on the communication line L1 is good.

On the other hand, the reception line selection function of the line selection unit 104 determines that the reception data quality of the communication line L1 is not good when the reception data quality of the communication line L1 does not satisfy a predetermined reception data quality standard. The reception line selection function of the line selection unit 104 selects the communication line L2 as the reception line for receiving data from the fixed station 200 when the quality of received data on the communication line L1 is not good.

In addition, when the received data quality of the communication line L1 is not good and data is not received from the fixed station 200 via the communication line L2, the reception line selection function of the line selection unit 104 selects the communication line Request to start data transmission using L2. The second communication terminal 102 notifies the line selection unit 104 via the control unit 103 whether data has arrived from the fixed station 200 via the communication line L2. A communication start request requesting to start data transmission using communication line L2 is transmitted from line selection unit 104 to fixed station 200 via control unit 103 via either communication line L1 or L2. Ru.

Based on the reception line selection result of the line selection unit 104, the control unit 103 determines whether the reception line for receiving data from the fixed station 200 is the communication line L1 or the communication line L2. The control unit 103 transmits the received data received from the fixed station 200 via the reception line to the mobile station side system 10.

When the reception line selection result of the line selection unit 104 is the communication line L1, the control unit 103 determines the communication line L1 as the reception line for receiving data from the fixed station 200.

When the reception line selection result of the line selection unit 104 is the communication line L2, when data is received from the fixed station 200 via the communication line L2, the control unit 103 selects the reception line for receiving data from the fixed station 200 as the communication line. The line L2 is determined.

On the other hand, when the reception line selection result of the line selection unit 104 is the communication line L2, and the data has not arrived from the fixed station 200 via the communication line L2, the control unit 103 selects the communication line L1 to receive the data from the fixed station 200. Let this be the receiving line that receives.

When the reception line selection result of the line selection unit 104 is the communication line L2, the control unit 103 selects the fixed station when the state changes from the state in which no data is received from the fixed station 200 to the state in which data is received through the communication line L2. 200 is determined to be the communication line L2.

(Fixed station)
Fixed station 200 shown in FIG. 1 will be explained.

The first communication terminal 201 and the second communication terminal 202 communicate using the communication network NW3. The communication network NW3 may be a wireless communication network or a wired communication network. Since the fixed station 200 does not communicate while moving, even if the communication network NW3 is a wireless communication network, the wireless communication quality is stable and good. In this embodiment, the first communication terminal 201 and the second communication terminal 202 use the same communication network NW3, but the first communication terminal 201 and the second communication terminal 202 may use different communication networks. good.

The first communication terminal 201 of the fixed station 200 establishes a communication line L1 with the first communication terminal 101 of the mobile station 100. The second communication terminal 202 of the fixed station 200 establishes a communication line L2 with the second communication terminal 102 of the mobile station 100.

The first communication terminal 201 measures the received data quality of data received from the first communication terminal 101 of the mobile station 100 via the communication line L1. The received data quality includes, for example, whether or not data is normally received, a packet loss rate, jitter, and an image quality evaluation value of image data.

The second communication terminal 202 determines whether data has arrived from the second communication terminal 102 of the mobile station 100 via the communication line L2.

The control unit 203 controls the fixed station 200. The control unit 203 controls the start and end of communication of the fixed station 200 in accordance with instructions to start and end communication from the operator of the fixed station 200, the fixed station side system 20, and the like. The fixed station side system 20 is, for example, a remote monitoring system for remotely monitoring an autonomous vehicle.

The control unit 203 transmits the transmission data received from the fixed station system 20 to the mobile station 100 through at least one of the communication line L1 and the communication line L2. The communication line mainly used as a transmission line for transmitting data to the mobile station 100 is the communication line L1. When the control unit 203 receives the transmission line selection result from the mobile station 100, it determines the transmission line for transmitting data to the mobile station 100 from the communication lines L1 and L2 based on the transmission line selection result.

The control unit 203 transmits the received data received from the mobile station 100 to the fixed station side system 20. The communication line mainly used as a reception line for receiving data from the mobile station 100 is the communication line L1. When the control unit 203 receives the reception line selection result from the line selection unit 204, the control unit 203 determines the reception line for receiving data from the mobile station 100 from the communication lines L1 and L2 based on the reception line selection result.

Note that if data is normally received from the mobile station 100 only from one of the communication lines L1 and L2, the control unit 203 determines whether the data is normally received from the mobile station 100, regardless of the reception line selection result of the line selection unit 204. The receiving communication line is determined to be the receiving line that receives data from the mobile station 100.

When the fixed station 200 transmits data to the mobile station 100, the control unit 203 adjusts the amount of data to be transmitted by changing the transmission bit rate etc. according to the performance of the first communication terminal 201 and the second communication terminal 202. It may also have a function.

The line selection unit 204 has a reception line selection function.
In this embodiment, the line selection unit 104 of the mobile station 100 has a transmission line selection function, the mobile station 100 notifies the fixed station 200 of the transmission line selection result, and the control unit 203 of the fixed station 200 selects the transmission line from the mobile station 100. Based on the notified transmission line selection result, a transmission line for transmitting data to the mobile station 100 from the communication lines L1 and L2 is determined. Therefore, in this embodiment, the line selection section 204 of the fixed station 200 does not need to have a transmission line selection function.
Note that the line selection unit 204 of the fixed station 200 also has a transmission line selection function, and the mobile station 100 notifies the fixed station 200 of the prediction result of the wireless communication quality of the communication line L1 by the communication quality prediction unit 110. The transmission line selection function of the line selection unit 204 may select whether or not to perform data transmission using the communication line L2 based on the prediction result of the wireless communication quality of the communication line L1. In this case, the control unit 203 of the fixed station 200 determines the transmission line for transmitting data to the mobile station 100 from the communication lines L1 and L2 based on the transmission line selection result of the line selection unit 204.

The reception line selection function of the line selection unit 204 selects which of the communication lines L1 and L2 to receive data from the mobile station 100 based on the received data quality of the communication line L1 of the first communication terminal 201. Select which line to use for reception. The received data quality includes, for example, whether or not data is normally received, a packet loss rate, jitter, and an image quality evaluation value of image data. The received data quality is notified from the first communication terminal 201 to the line selection section 204 via the control section 203.

The reception line selection function of the line selection unit 204 determines that the reception data quality of the communication line L1 is good when the reception data quality of the communication line L1 satisfies a predetermined reception data quality standard. The reception line selection function of the line selection unit 204 selects the communication line L1 as a reception line for receiving data from the mobile station 100 when the quality of received data on the communication line L1 is good.

On the other hand, the reception line selection function of the line selection unit 204 determines that the reception data quality of the communication line L1 is not good when the reception data quality of the communication line L1 does not satisfy a predetermined reception data quality standard. The reception line selection function of the line selection unit 204 selects the communication line L2 as the reception line for receiving data from the mobile station 100 when the quality of received data on the communication line L1 is not good.

In addition, the reception line selection function of the line selection unit 204 selects a communication line for the mobile station 100 when the received data quality of the communication line L1 is not good and data is not received from the mobile station 100 via the communication line L2. Request to start data transmission using L2. The second communication terminal 202 notifies the line selection unit 204 via the control unit 203 whether data has arrived from the mobile station 100 via the communication line L2. A communication start request requesting to start data transmission using communication line L2 is transmitted from line selection unit 204 to mobile station 100 via control unit 203 via either communication line L1 or L2. Ru.

Based on the reception line selection result of the line selection unit 204, the control unit 203 determines whether the reception line for receiving data from the mobile station 100 is the communication line L1 or the communication line L2. The control unit 203 transmits the received data received from the mobile station 100 via the reception line to the fixed station side system 20.

When the reception line selection result of the line selection unit 204 is the communication line L1, the control unit 203 determines the communication line L1 as the reception line for receiving data from the mobile station 100.

When the reception line selection result of the line selection unit 204 is the communication line L2, when data is received from the mobile station 100 via the communication line L2, the control unit 203 selects the reception line for receiving data from the mobile station 100 as the communication line. The line L2 is determined.

On the other hand, when the reception line selection result of the line selection unit 204 is the communication line L2, and the data has not arrived from the mobile station 100 via the communication line L2, the control unit 203 selects the communication line L1 to receive the data from the mobile station 100. Let this be the receiving line that receives.

When the reception line selection result of the line selection unit 204 is the communication line L2, the control unit 203 selects the mobile station when the state changes from a state in which no data is received from the mobile station 100 to a state in which data is received through the communication line L2. 100 is determined to be the communication line L2.

Next, the communication method according to this embodiment will be explained with reference to FIGS. 2 and 3.

(Transmission processing on the transmitting side (transmitting station))
The procedure of transmission processing on the transmitting side (transmitting station) will be explained with reference to FIG. FIG. 2 is a flowchart illustrating an example of a procedure of transmission processing on the transmitting side (transmitting station) according to the present embodiment. Here, the explanation will be given using the mobile station 100 as an example of the transmitting side (transmitting station).

The mobile station 100 starts communication with the fixed station 200 in accordance with an instruction to start communication from the operator of the mobile station 100, the mobile station system 10, or the like. The mobile station 100 transmits the transmission data received from the mobile station side system 10 to the fixed station 200.

(Step S1) The mobile station 100 transmits data to the fixed station 200 using the communication line L1 (first communication line) using the first communication terminal 101 (first transmission unit).

(Step S2) The mobile station 100 uses the communication quality prediction unit 110 to periodically predict the future wireless communication quality for the communication line L1. If the prediction result of the future wireless communication quality for the communication line L1 is "deterioration", the process advances to step S4. On the other hand, if the wireless communication quality prediction result is "good", the process advances to step S3.

(Step S3) The mobile station 100 determines whether there is a request from the fixed station 200 to start communication on the communication line L2 (second communication line). As a result, if there is a request to start communication on the communication line L2, the process advances to step S4. On the other hand, if there is no request to start communication on the communication line L2, the process returns to step S1.

(Step S4) In addition to transmitting data to the fixed station 200 using the communication line L1, the mobile station 100 also transmits data to the fixed station 200 using the communication line L2 using the second communication terminal 102 (second transmitter). Transmission will also start.

(Step S5) The mobile station 100 checks the prediction result of the future wireless communication quality for the communication line L1 by the communication quality prediction unit 110. If the prediction result of future wireless communication quality for the communication line L1 is "good", the process advances to step S6; otherwise, step S5 is repeated.

(Step S6) The mobile station 100 ends data transmission by the second communication terminal 102 to the fixed station 200 using the communication line L2. After this, the process returns to step S1.

When the mobile station 100 receives an instruction to terminate communication from the operator of the mobile station 100, the mobile station system 10, etc., the mobile station 100 terminates the transmission process shown in FIG. 2.

Note that in the above description of the transmission process, the mobile station 100 was used as an example of the transmission side (transmission station), but the transmission process of FIG. 2 may be applied to the fixed station 200 as the transmission station. In this embodiment, the line selection unit 104 of the mobile station 100 has a transmission line selection function, and the mobile station 100 notifies the fixed station 200 of the transmission line selection result, but the present invention is not limited to this. The line selection unit 204 of the fixed station 200 has a transmission line selection function, and the mobile station 100 notifies the fixed station 200 of the prediction result of the wireless communication quality of the communication line L1 by the communication quality prediction unit 110, and selects the line of the fixed station 200. The transmission line selection function of the unit 204 may select whether to perform data transmission using the communication line L2 based on the predicted result of the wireless communication quality of the communication line L1.

(Reception processing on the receiving side (receiving station))
The procedure of reception processing on the receiving side (receiving station) will be explained with reference to FIG. FIG. 3 is a flowchart illustrating an example of a procedure for receiving processing on the receiving side (receiving station) according to the present embodiment. Here, the fixed station 200 will be described as an example of the receiving side (receiving station).

The fixed station 200 starts communication with the mobile station 100 in accordance with an instruction to start communication from the operator of the fixed station 200, the fixed station system 20, or the like. The fixed station 200 transmits the received data received from the mobile station 100 to the fixed station side system 20.

(Step S11) The fixed station 200 receives data from the mobile station 100 using the communication line L1 (first communication line) using the first communication terminal 201 (first reception unit).

(Step S12) The fixed station 200 measures the received data quality of the data received from the mobile station 100 via the communication line L1. If the received data quality of the communication line L1 is good, the process returns to step S11. On the other hand, if the received data quality of the communication line L1 is not good, the process advances to step S13.

(Step S13) The fixed station 200 determines whether data has arrived from the mobile station 100 via the communication line L2 (second communication line). If data has arrived from the mobile station 100 via the communication line L2, the process advances to step S15. On the other hand, if data has not arrived from the mobile station 100 via the communication line L2, the process advances to step S14.

(Step S14) The fixed station 200 requests the mobile station 100 to start data transmission using the communication line L2. After this, the process returns to step S11. Then, the fixed station 200 continues to receive data from the mobile station 100 using the communication line L1, and when the received data quality of the communication line L1 is not good (step S12, NO), the fixed station 200 continues to receive data from the mobile station 100 using the communication line L2. When data has arrived from 100 (step S13, YES), the process advances to step S15.

(Step S15) The fixed station 200 switches the receiving line for receiving data from the mobile station 100 from the communication line L1 to the communication line L2. After this, the process returns to step S12. Then, the fixed station 200 receives data from the mobile station 100 using the communication line L2 using the second communication terminal 202 (second receiving unit) until the quality of the received data on the communication line L1 becomes good. When the quality of the received data on the communication line L1 becomes good (step S12, YES), the fixed station 200 returns the reception line for receiving data from the mobile station 100 from the communication line L2 to the communication line L1 (step S11).

When the fixed station 200 receives an instruction to terminate communication from the operator of the fixed station 200, the fixed station side system 20, etc., the fixed station 200 terminates the reception process shown in FIG. 3.

In the above description of the reception process, the fixed station 200 is taken as an example of the reception side (reception station), but the reception process of the mobile station 100 as a reception station is also similar.

According to the first embodiment described above, in the communication system 1 in which at least one of the transmitting station and the receiving station is the mobile station 100, the transmitting station uses the prediction result of the wireless communication quality of the communication line L1 of the mobile station 100. Based on this, it is selected whether to perform data transmission using the communication line L2. Thereby, it is possible to adapt to local fluctuations or deterioration of wireless communication quality in the mobile station 100. On the other hand, the receiving station receives data from the transmitting station through either communication line L1 or L2, independently of the transmitting station, based on the received data quality of the communication line L1 of the own receiving station. Select whether to use the receiving line. Thereby, communication quality can be improved so that communication interruptions do not occur at the receiving station as much as possible.

Note that the transmitting station and the receiving station may decide whether to use the communication line L2 depending on the type of data. For example, if the communication line L1 has a higher speed and larger capacity than the communication line L2, but the communication line L2 is a more stable line than the communication line L1, the above-described embodiment may be used for remote monitoring video with a large amount of data. Although such communication methods (FIGS. 2 and 3) are applied, vehicle control signals and vehicle monitoring signals that require more stable transmission may be always sent via the communication line L2.

[Second embodiment]
FIG. 4 is a block diagram showing a configuration example of a communication system according to the second embodiment. In FIG. 4, parts corresponding to those in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

In the communication system 1 according to the first embodiment described above, the fixed station 200 shown in FIG. 1 includes the first communication terminal 201 for establishing the communication line L1 and the second communication terminal 202 for establishing the communication line L2. In the communication system 1a according to the second embodiment, a fixed station 200a shown in FIG. 4 establishes a communication line L1 and a communication line L2 with the mobile station 100 using one communication terminal 201a. Other than this point, this embodiment is the same as the first embodiment described above.

[Third embodiment]
FIG. 5 is a block diagram showing a configuration example of a communication system according to the third embodiment. In FIG. 5, parts corresponding to those in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

In the communication system 1b according to the third embodiment shown in FIG. 5, mobile stations (mobile station 100 and mobile station 300) communicate with each other. In the communication system 1b, the mobile station 100 serves as a transmitting station and transmits data to the mobile station 300 (receiving station), and the mobile station 100 serves as a receiving station and receives data from the mobile station 300 (transmitting station). There are cases and cases.

Mobile station 300 has a similar configuration to mobile station 100. Mobile station 100 and mobile station 300 each include a communication quality prediction unit 110. The communication quality prediction unit 110 of the mobile station 100 predicts the wireless communication quality of the communication line L1 in the mobile station 100. The communication quality prediction unit 110 of the mobile station 300 predicts the wireless communication quality of the communication line L1 in the mobile station 300.

In the transmission process of the transmitting station in the communication system 1b according to the third embodiment, the prediction result of the wireless communication quality of the communication line L1 by the communication quality prediction unit 110 of the mobile station 100 and the communication quality prediction result of the communication quality prediction unit 110 of the mobile station 300 are used. If at least one of the prediction results of the wireless communication quality of line L1 is "deteriorated" (step S2 in FIG. 2, YES), in addition to transmitting data to the receiving station using communication line L1, Data transmission to the receiving station using L2 is also started (step S4).

The reception processing of the receiving station in the communication system 1b according to the third embodiment is the same as in the first embodiment described above.

According to each of the embodiments described above, in a communication system in which at least one of a transmitting station and a receiving station is a mobile station, when using a plurality of communication lines between the transmitting station and the receiving station, It is possible to adapt to local fluctuations or deterioration of wireless communication quality, and it is possible to improve communication quality so as to prevent communication interruptions as much as possible.

Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like may be made without departing from the gist of the present invention.

Further, a computer program for realizing the functions of each device described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Note that the "computer system" here may include hardware such as an OS and peripheral devices.
Furthermore, "computer-readable recording media" refers to flexible disks, magneto-optical disks, ROMs, writable non-volatile memories such as flash memory, portable media such as DVDs (Digital Versatile Discs), and media built into computer systems. A storage device such as a hard disk.

Furthermore, "computer-readable recording medium" refers to volatile memory (for example, DRAM (Dynamic It also includes those that retain programs for a certain period of time, such as Random Access Memory).
Further, the program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in a transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Moreover, the above-mentioned program may be for realizing a part of the above-mentioned functions. Furthermore, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

1, 1a, 1b...communication system, 100,300...mobile station, 200,200a...fixed station, 101,201...first communication terminal, 102,202...second communication terminal, 103,203...control unit, 104, 204... Line selection unit, 110... Communication quality prediction unit, 201a... Communication terminal

Claims (14)

In a communication system comprising a transmitting station and a receiving station,
At least one of the transmitting station and the receiving station is a mobile station,
The mobile station includes a communication quality prediction unit that predicts wireless communication quality for a first communication line between the transmitting station and the receiving station,
The transmitting station is
a first transmitter that transmits data using the first communication line;
a second transmitting unit that transmits data using a second communication line between the transmitting station and the receiving station;
a transmission line selection unit that selects whether or not to perform data transmission using the second communication line by the second transmission unit based on a prediction result of wireless communication quality of the first communication line of the mobile station; Equipped with
The receiving station is
a first receiving unit that receives data using the first communication line;
a second receiving unit that receives data using the second communication line;
Based on the received data quality of the first communication line of the first receiving unit and the presence or absence of the received data of the second communication line , which communication line is selected between the first communication line and the second communication line, a receiving line selection unit that selects whether to use a receiving line for receiving data from the transmitting station;
Communications system. The transmitting station is
In the case where data is being transmitted only through the first communication line and the predicted result of the wireless communication quality of the first communication line is poor, in addition to the data transmission through the first communication line, the second communication line may be used. Start sending data using
When data transmission is being performed on both the first communication line and the second communication line, data transmission on the second communication line is terminated when a prediction result of wireless communication quality on the first communication line is good. and transmitting data only through the first communication line,
The communication system according to claim 1. The transmission line selection section includes:
If the predicted result of the wireless communication quality of the first communication line is poor, start data transmission using the second communication line,
stopping data transmission using the second communication line when the prediction result of the wireless communication quality of the first communication line is good;
The communication system according to claim 1 or 2 . When the second communication line is a more stable line than the first communication line, the transmitting station and the receiving station always use the second communication line for signals that require stable transmission. ,
The communication system according to any one of claims 1 to 3 . In the receiving station, when the received data quality of the first communication line of the first receiving unit does not satisfy a predetermined received data quality standard, the data does not reach the second receiving unit via the second communication line. Sometimes, requesting the transmitting station to start data transmission using the second communication line;
The communication system according to any one of claims 1 to 4 . The communication quality prediction unit includes:
Calculating a wireless communication quality evaluation value based on the wireless quality measurement value of the first communication line,
predicting that the wireless communication quality of the first communication line will deteriorate if the evaluation value no longer satisfies a predetermined wireless communication quality evaluation standard;
predicting that the wireless communication quality of the first communication line is good if the evaluation value satisfies a predetermined wireless communication quality evaluation standard;
A communication system according to any one of claims 1 to 5 . The communication quality prediction unit includes:
obtaining a distance between the mobile station and a base station of the first communication line to which the mobile station connects;
predicting that the wireless communication quality of the first communication line will deteriorate if the distance no longer satisfies a predetermined wireless communication quality evaluation standard;
predicting that the wireless communication quality of the first communication line is good if the distance satisfies a predetermined wireless communication quality evaluation standard;
A communication system according to any one of claims 1 to 5 . The communication quality prediction unit includes:
The current position of the mobile station and the mobile station are determined based on the communication quality map in which the wireless communication quality of the wireless communication network used for the first communication line is recorded for each point and the planned travel route information of the mobile station. Calculate the distance between points on the planned travel route that do not meet the predetermined wireless communication quality evaluation criteria,
predicting that the wireless communication quality of the first communication line will deteriorate when the distance falls within a predetermined threshold;
predicting that the wireless communication quality of the first communication line is good if the distance exceeds a predetermined threshold;
A communication system according to any one of claims 1 to 5 . The received data quality is one or more of the following: normal reception of data, packet loss rate, jitter, and image quality evaluation value of image data;
A communication system according to any one of claims 1 to 8 . The transmitting station of a communication system in which at least one of the transmitting station and the receiving station is a mobile station,
a first transmitting unit that transmits data using a first communication line between the transmitting station and the receiving station;
a second transmitting unit that transmits data using a second communication line between the transmitting station and the receiving station;
a transmission line selection unit that selects whether or not to perform data transmission using the second communication line by the second transmission unit based on a prediction result of wireless communication quality of the first communication line of the mobile station;
Equipped with
The transmitting station is
In the case where data is being transmitted only through the first communication line and the predicted result of the wireless communication quality of the first communication line is poor, in addition to the data transmission through the first communication line, the second communication line may be used. Start sending data using
When data transmission is being performed on both the first communication line and the second communication line, data transmission on the second communication line is terminated when a prediction result of wireless communication quality on the first communication line is good. and transmitting data only through the first communication line,
transmitting station. At the mobile station,
a communication quality prediction unit that predicts wireless communication quality for a first communication line between the mobile station and a communication partner of the mobile station;
a first transmitter that transmits data using the first communication line;
a second transmitter that transmits data using a second communication line between the mobile station and the communication partner;
a transmission line selection unit that selects whether or not the second transmission unit should perform data transmission using the second communication line based on a prediction result of wireless communication quality for the first communication line;
a first receiving unit that receives data using the first communication line;
a second receiving unit that receives data using the second communication line;
Based on the received data quality of the first communication line of the first receiving unit and the presence or absence of the received data of the second communication line , which communication line is selected between the first communication line and the second communication line, a receiving line selection unit for selecting a receiving line to be used for receiving data from the communication partner;
A mobile station equipped with In a communication method for a communication system comprising a transmitting station and a receiving station,
At least one of the transmitting station and the receiving station is a mobile station,
a first transmission step in which the transmitting station performs data transmission using a first communication line between the transmitting station and the receiving station;
a communication quality prediction step in which the mobile station predicts wireless communication quality for the first communication line;
Whether or not the transmitting station performs data transmission using a second communication line between the transmitting station and the receiving station based on a prediction result of the wireless communication quality of the first communication line of the mobile station. a transmission line selection step for selecting the
a second transmission step in which the transmitting station performs data transmission using the second communication line based on the selection result of the transmission line selection step;
a first receiving step in which the receiving station receives data using the first communication line;
a second receiving step in which the receiving station receives data using the second communication line;
The receiving station determines which of the first communication line and the second communication line is selected based on the quality of the received data on the first communication line and the presence or absence of the received data on the second communication line in the first receiving step. a receiving line selection step of selecting whether to use the communication line as a receiving line for receiving data from the transmitting station;
communication methods, including A computer in a transmitting station of a communication system in which at least one of a transmitting station and a receiving station is a mobile station,
a first transmitting step of transmitting data using a first communication line between the transmitting station and the receiving station;
a second transmitting step of transmitting data using a second communication line between the transmitting station and the receiving station;
a transmission line selection step of selecting whether to perform data transmission using the second communication line in the second transmission step, based on a prediction result of wireless communication quality of the first communication line of the mobile station;
A computer program for executing
The transmitting station is
In the case where data is being transmitted only through the first communication line and the predicted result of the wireless communication quality of the first communication line is poor, in addition to the data transmission through the first communication line, the second communication line may be used. Start sending data using
When data transmission is being performed on both the first communication line and the second communication line, data transmission on the second communication line is terminated when a prediction result of wireless communication quality on the first communication line is good. and transmitting data only through the first communication line,
computer program. to the mobile station computer,
a communication quality prediction step of predicting wireless communication quality on a first communication line between the mobile station and a communication partner of the mobile station;
a first transmission step of transmitting data using the first communication line;
a second transmission step of transmitting data using a second communication line between the mobile station and the communication partner;
a transmission line selection step of selecting whether or not to perform data transmission using the second communication line in the second transmission step, based on a prediction result of wireless communication quality for the first communication line;
a first receiving step of receiving data using the first communication line;
a second receiving step of receiving data using the second communication line;
Based on the quality of the received data on the first communication line in the first receiving step and the presence or absence of the received data on the second communication line , which communication line is selected between the first communication line and the second communication line, a receiving line selection step of selecting a receiving line to be used for receiving data from the communication partner;
A computer program for running.

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