JP2021064816A - Communication device and communication method - Google Patents

Abstract

To reduce the packet loss in a specific communication operation to which real-time performance is required when a coexistence operation between a first communication operation and a second communication operation is executed.SOLUTION: A communication device includes a first communication circuit for executing a first communication operation according to a first wireless communication standard, a second communication circuit for executing a second communication operation according to a second wireless communication standard, and a control circuit for controlling the first communication operation and the second communication operation. The first communication circuit can execute a specific communication operation to which real-time performance is required. The control circuit can cause the first communication circuit and the second communication circuit to execute a coexistence operation of time-divisionally and alternately executing the first communication operation and the second communication operation, and changes the allocation of time for the first communication operation and the second communication operation based on the presence or absence of the specific communication operation in the first communication operation when the coexistence operation is executed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a communication device and a communication method.

In recent years, by alternately executing the first communication operation according to the first wireless communication standard and the second communication operation according to the second wireless communication standard different from the first wireless communication standard in a time division manner. A technique related to a communication operation in which two types of communication operations coexist (hereinafter, may be referred to as "coexistence operation") has been put into practical use. By using this technology, for example, real-time performance corresponding to stream distribution (data transmission / reception method for sequentially reproducing transmitted voice data and video data in real time) and voice calls according to the first wireless communication standard is required. Specific communication operation (hereinafter sometimes referred to as "real-time operation") and normal operation for transmitting and receiving normal data other than stream distribution and voice call according to the second wireless communication standard are executed at the same time. be able to.

Special Table 2010-535461A

However, in the conventional communication method, when the coexistence operation of the first communication operation and the second communication operation is executed, it is compared with the case where the first communication operation or the second communication operation is executed alone. Since the execution period of each communication operation is limited, sufficient time cannot be secured in each communication operation, and packet loss may occur. In particular, when the first communication operation is a real-time operation corresponding to stream distribution, voice call, etc., packet loss causes sound skipping, and the problem becomes more remarkable.

The present invention has been made in view of the above problems, and is a packet in a specific communication operation that requires real-time performance when executing a coexistence operation of the first communication operation and the second communication operation. The purpose is to reduce loss.

A communication device according to an embodiment has a first communication circuit that executes a first communication operation according to a first wireless communication standard, and a second communication device according to a second wireless communication standard different from the first wireless communication standard. A second communication circuit that executes a communication operation and a control circuit that controls the first communication operation and the second communication operation are provided, and the first communication circuit has real-time performance in the first communication operation. The first communication circuit performs a coexistence operation in which the first communication operation and the second communication operation are alternately executed in a time-divided manner. And the second communication circuit can be executed, and when the coexistence operation is executed, the first communication operation and the second communication operation are performed based on the presence or absence of the specific communication operation in the first communication operation. Change the time allocation with the communication operation of.

According to each embodiment of the present invention, when the coexistence operation of the first communication operation and the second communication operation is executed, the first communication operation is based on the presence or absence of a specific communication operation that requires real-time performance. By changing the time allocation between the communication operation and the second communication operation, the execution period of the first communication operation can be optimized for a specific communication operation, and the packet loss in the first communication operation can be reduced. Can be reduced.

The figure which shows an example of the hardware configuration of a communication device. A timing chart showing an example of normal operation of a communication device. The flowchart which shows an example of the normal operation for one cycle of a communication device. A timing chart showing an example of real-time operation of a communication device. The flowchart which shows an example of the operation at the time of operation switching of a communication device. The flowchart which shows an example of the operation at the time of operation switching of a communication device.

Hereinafter, each embodiment of the present invention will be described with reference to the accompanying drawings. Regarding the description of the specification and the drawings according to each embodiment, the components having substantially the same functional configuration are designated by the same reference numerals, and the superimposed description will be omitted.

<First Embodiment>
The communication device 1 according to the first embodiment will be described with reference to FIGS. 1 to 5. The communication device 1 according to the present embodiment is a communication device capable of alternately executing a communication operation according to a first wireless communication standard and a communication operation according to a second wireless communication standard in a time-division manner.

First, the hardware configuration of the communication device 1 will be described. FIG. 1 is a diagram showing an example of a hardware configuration of the communication device 1. The communication device 1 of FIG. 1 includes a first communication circuit 11, a second communication circuit 12, a control circuit 13, an antenna 14, and a switch circuit 15.

The first communication circuit 11 is a circuit that executes a communication operation with an opposite terminal 2 which is a communication partner according to the first wireless communication standard. The communication operation executed by the first communication circuit 11 is referred to as a first communication operation. The first wireless communication standard can be any wireless communication standard capable of performing real-time operation (a specific communication operation that requires real-time performance corresponding to stream distribution, voice call, etc.). The first wireless communication standard is, for example, Bluetooth®, Wi-Fi®, WiMAX®, or LTE, but is not limited to this. Further, the opposite terminal 2 can be any communication device capable of communicating according to the first wireless communication standard.

The second communication circuit 12 is a circuit that executes a communication operation with the opposite terminal 3 as a communication partner according to a second wireless communication standard different from the first wireless communication standard. The communication operation executed by the second communication circuit 12 is referred to as a second communication operation. The second wireless communication standard can be any wireless LAN (Local Area Network) standard. The second wireless communication standard is, for example, Wi-Fi or WiMAX, but is not limited to this. Further, the opposite terminal 3 can be any communication device capable of communicating according to the second wireless communication standard. In the present embodiment, it is assumed that the second communication circuit 12 operates as an AP (Access Point) capable of executing a scanning operation using a beacon signal in the second communication operation. When the scanning operation using the beacon signal is not executed in the communication operation of the above, the second wireless communication standard may be Bluetooth.

The control circuit 13 is a circuit that controls the first communication operation by the first communication circuit 11 and the second communication operation by the second communication circuit 12, respectively. The control circuit 13 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a connection interface for connecting to the first communication circuit 11 and the second communication circuit 12, a flash memory, and the like. Equipped with an auxiliary storage device. The function of the control circuit 13 is realized by the CPU executing the program stored in the ROM or the like on the RAM. The operation of the control circuit 13 will be described later.

The antenna 14 is connected to the first communication circuit 11 or the second communication circuit 12 via the switch circuit 15 to transmit and receive radio signals. That is, the antenna 14 is shared by the first communication circuit 11 and the second communication circuit 12.

The switch circuit 15 connects the antenna 14 to the first communication circuit 11 or the second communication circuit 12. The switching of the connection by the switch circuit 15 is controlled by the control circuit 13.

The hardware configuration of the communication device 1 is not limited to the example of FIG. For example, in the example of FIG. 1, it is assumed that the first communication circuit 11 and the second communication circuit 12 are independent communication modules, but the first communication circuit 11 and the second communication circuit 12 are integrated. It may be a communication module. Further, the first communication circuit 11 and the second communication circuit 12 may be communication circuits such as cognitive radio whose functions are defined by software. Further, in the example of FIG. 1, it is assumed that the first communication circuit 11 and the second communication circuit 12 are controlled by one control circuit 13, but the first communication circuit 11 and the second communication circuit 12 are , The function of the control circuit 13 may be realized by being controlled by two independent control circuits and coordinating the two control circuits.

Next, the normal operation and the real-time operation of the communication device 1 will be described. In the following description, the real-time operation is a specific communication operation that is executed in the first communication operation and is required to have real-time performance corresponding to stream distribution or voice call. Further, in the following description, the normal operation is a communication operation other than the above-mentioned specific communication operation executed in the first communication operation, and is a normal data transmission / reception that does not require real-time performance or a beacon signal. It includes scanning operations using the data, transmission of an acknowledgment corresponding to the received data, and the like. Further, in the following description, it is assumed that the first wireless communication standard is Bluetooth and the second wireless communication standard is a wireless LAN standard such as Wi-Fi. Further, hereinafter, the first communication operation may be referred to as "BT", and the second communication operation may be referred to as "WLAN".

First, the normal operation of the communication device 1 will be described. FIG. 2 is a timing chart showing an example of the communication operation of the communication device 1 when the first communication operation is a normal operation.

As shown in FIG. 2, the communication device 1 is capable of coexistence operation in which the first communication operation (BT) and the second communication operation (WLAN) are alternately executed in a time division manner during the cycle T. .. In the example of FIG. 2, the first communication operation is executed before the second communication operation, but the order may be reversed.

The first communication operation and the second communication operation are executed during the execution periods T1 and T2 set by the control circuit 13, respectively. The default values for the execution periods T1 and T2 are set in advance, and are set to the default values in the initial state and the normal operation. In the example of FIG. 2, it is assumed that the default values of the execution periods T1 and T2 are equal, but the default values of the execution periods T1 and T2 are not limited to this.

Further, in the second communication operation, the beacon signal (thick line hatched portion in FIG. 2) is transmitted at a predetermined interval BI set by the control circuit 13. Hereinafter, the transmission interval BI of the beacon signal may be referred to as "beacon interval BI". The beacon interval BI is preset with a default value, and is set to the default value in the initial state or normal operation. In the example of FIG. 2, it is assumed that the default value of the beacon interval BI is equal to the period T, but the default value of the beacon interval BI is not limited to this.

FIG. 3 is a flowchart showing an example of a coexistence operation for one cycle of the communication device 1 when the first communication operation is a normal operation. It is assumed that the second communication operation is being executed at the start of FIG.

The control circuit 13 controls the second communication operation until the start time of the first communication operation arrives (step S101: NO). When the start time of the first communication operation arrives (YES in step S101), the control circuit 13 causes the second communication circuit 12 to stop the second communication operation (step S102), and controls the switch circuit 15. The antenna 14 is connected to the first communication circuit 11 (step S103), and the first communication circuit 11 starts the first communication operation (step S104). At this time, the control circuit 13 sets the execution period T1 (execution period of the first communication operation) to the default value. After that, the first communication circuit 11 executes the first communication operation during the execution period T1. Specifically, the first communication circuit 11 wirelessly transmits data and the like input from the control circuit 13 via the antenna 14, and inputs the data and the like wirelessly received via the antenna 14 to the control circuit 13. To do.

After that, the control circuit 13 controls the first communication operation until the start time of the second communication operation arrives (step S105: NO). When the start time of the second communication operation arrives (YES in step S105), the control circuit 13 causes the first communication circuit 11 to stop the first communication operation (step S106), controls the switch circuit 15, and controls the switch circuit 15. The antenna 14 is connected to the second communication circuit 12 (step S107), and the second communication circuit 12 starts the second communication operation (step S108). At this time, the control circuit 13 sets the execution period T2 (execution period of the second communication operation) and the beacon interval BI to the default values. After that, the second communication circuit 12 executes the second communication operation during the execution period T2. Specifically, the second communication circuit 12 wirelessly transmits the data or the like input from the control circuit 13 via the antenna 14, and inputs the data or the like wirelessly received via the antenna 14 to the control circuit 13. To do. Further, the second communication circuit 12 transmits a beacon for each beacon interval BI. When the coexistence operation is continued, a series of operations from step S101 to step S108 shall be repeated.

Next, the real-time operation of the communication device 1 will be described. FIG. 4 is a timing chart showing an example of the communication operation of the communication device 1 when the first communication operation is a real-time operation. Hereinafter, the real-time operation of the communication device 1 is assumed to be a communication operation corresponding to stream distribution or voice call.

As shown in FIG. 4, when the real-time operation is executed in the first communication operation, the execution period T1 is set longer than the default value. As a result, the execution period of the real-time operation in the first communication operation can be secured longer than in the case of the normal operation, so that packet loss is reduced and sound skipping in stream distribution or voice call by the first communication operation is suppressed. can do.

On the other hand, since the period T of the normal operation and the real-time operation is the same, the execution period T2 is set shorter than the default value in the real-time operation. That is, in the real-time operation, the ratio of the execution period T1 to the execution period T2 is larger than the initial state (the ratio when the execution periods T1 and T2 are the default values), and the ratio of the execution period T2 to the execution period T1 is smaller than the initial state. Therefore, the time allocation of the execution periods T1 and T2 (time allocation between the first communication operation and the second communication operation) is set. As a result, the throughput of data transmission / reception by the second communication operation tends to decrease. Therefore, in the real-time operation, as shown in FIG. 4, the beacon interval BI is set to be longer than the default value, that is, the initial state. As a result, the operation time of the scan operation in the cycle T (the average value of the time required for the scan operation such as transmission of the beacon signal) is shortened. In other words, the time available for transmitting and receiving data by the second communication operation becomes longer than in the case where the beacon interval BI remains in the initial state. As a result, the communication load in the second communication operation (particularly the communication load at the time of data transmission / reception) can be reduced, and the decrease in the throughput of data transmission / reception due to the second communication operation can be suppressed. Hereinafter, the operation of reducing the communication load (particularly the communication load at the time of transmitting / receiving data) in the second communication operation may be referred to as a “load reduction operation”.

Since the real-time operation of the communication device 1 is the same as the normal operation except for the set values of the execution periods T1 and T2 and the beacon interval BI, the description thereof will be omitted.

Subsequently, the operation at the time of switching the operation of the communication device 1 (when switching between the normal operation and the real-time operation) will be described. FIG. 5 is a flowchart showing an example of the operation when the operation of the communication device 1 is switched. It is assumed that the normal operation is being executed at the start of FIG.

When the real-time operation starts in the first communication operation (step S201: YES), the control circuit 13 makes the execution period T1 longer than the default value (step S202), makes the execution period T2 shorter than the default value, and sets the beacon interval BI. Is longer than the default value (step S203). That is, the control circuit 13 changes the time allocation of the execution periods T1 and T2 and changes the time allocation so that the ratio of the execution period T1 to the execution period T2 becomes longer than the initial state in accordance with the start of the real-time operation. The conditions of the scan operation are changed so that the operation time of the scan operation is shorter than the initial state according to the change. Then, stream distribution or voice call is started. After that, the communication device 1 continues the communication operation under the above-mentioned setting conditions until the stream distribution or the voice call is completed (step S204: NO).

When the real-time operation is completed in the first communication operation (step S204: YES), the control circuit 13 returns the setting to the initial state (step S205). That is, the control circuit 13 sets the time allocation and the beacon interval BI of the execution periods T1 and T2 to the default values. Then, the normal operation is started. After that, the communication device 1 continues the normal operation until the real-time operation starts again.

As described above, according to the present embodiment, the control circuit 13 performs the coexistence operation of alternately executing the first communication operation and the second communication operation in a time-division manner in the first communication circuit and the second communication circuit. Can be executed. Then, in the coexistence operation, the control circuit 13 allocates time (first communication) of execution periods T1 and T2 based on the presence or absence of a real-time operation (a specific communication operation that requires real-time performance) in the first communication operation. The time allocation between the operation and the second communication operation) is changed. As a result, the execution period T1 can be optimized for the real-time operation, and the packet loss in the first communication operation can be reduced.

Specifically, according to the present embodiment, the execution period T1 is such that the ratio of the execution period T1 to the execution period T2 becomes longer than the initial state in accordance with the start of the real-time operation in the coexistence operation. , T2 time allocation is changed. As a result, it becomes easy to secure the time required for the real-time operation, and the packet loss in the first communication operation can be easily reduced. Moreover, the control circuit 13 returns the time allocation of the execution periods T1 and T2 to the desired state in accordance with the end of the real-time operation. As a result, the period during which the throughput of the second communication operation decreases can be limited to the period during which the real-time operation is executed in the first communication operation, and communication can be performed efficiently.

Further, according to the present embodiment, the control circuit 13 performs a load reducing operation for reducing the communication load in the second communication operation in accordance with the change in the time allocation of the execution periods T1 and T2 in the coexistence operation. To execute. As a result, the communication load in the second communication operation can be optimized according to the decrease in the execution period T2 due to the change in the time allocation of the execution periods T1 and T2, and the packet loss in the first communication operation is reduced. At the same time, it is possible to suppress a decrease in throughput in the second communication operation.

Further, according to the present embodiment, the real-time operation that is a specific communication operation is a communication operation corresponding to stream distribution or voice call. In stream distribution or voice call, packet loss causes sound skipping, so real-time performance is particularly strictly required from the viewpoint of sound skipping prevention and the like. Therefore, when the real-time operation is a communication operation corresponding to stream distribution or voice call, the above-mentioned effect becomes particularly remarkable.

Further, according to the present embodiment, the second communication circuit 12 can execute a scan operation using the beacon signal in the second communication operation, and the load reduction operation is the beacon interval BI in the second communication operation. Includes an operation of making (the transmission interval of the beacon signal transmitted in the scanning operation) longer than the initial state. As a result, even if the execution period T2 decreases due to the change in the time allocation of the execution periods T1 and T2, it becomes easy to secure the time for transmitting and receiving data in the second communication operation, and the second communication operation The decrease in throughput can be easily suppressed.

<Second Embodiment>
The communication device 1 according to the second embodiment will be described with reference to FIG. In the present embodiment, when the first communication operation is the above-mentioned real-time operation, the communication device 1 lengthens the beacon interval BI and second communication in accordance with the change in the time distribution of the execution periods T1 and T2. It also changes other settings in operation. That is, the load reduction operation in the second communication operation is not limited to the change in the beacon interval BI. Since the hardware configuration, normal operation, and real-time operation of the communication device 1 are the same as those in the first embodiment, the description thereof will be omitted.

Hereinafter, the operation at the time of switching the operation of the communication device 1 in the present embodiment will be described. FIG. 6 is a flowchart showing an example of the operation when the operation of the communication device 1 is switched. The flowchart of FIG. 6 corresponds to the addition of steps S206 and S207 between steps S203 and S204 in the flowchart of FIG. It is assumed that the normal operation is being executed at the start of FIG.

If the real-time operation starts in the first communication operation during the execution of the normal operation (step S201: YES), the control circuit 13 makes the execution period T1 longer than the default value (step S202) and sets the execution period T2 to the default value. It is made shorter and the beacon interval BI is made longer than the default value (step S203). That is, the control circuit 13 changes the time allocation of the execution periods T1 and T2 and changes the time allocation so that the ratio of the execution period T1 to the execution period T2 becomes longer than the initial state in accordance with the start of the real-time operation. In line with this, the beacon interval BI is made longer than the expected state so that the operation time of the scanning operation is shorter than the initial state.

Further, the control circuit 13 further changes the channel scanning method in the second communication operation according to the change in the time allocation of the execution periods T1 and T2 (step S206). Specifically, the control circuit 13 reduces the number of channels scanned by the second communication circuit 12 in one scan operation in the second communication operation from the initial state (default value). As a result, the operation time of the scan operation in one scan operation is shortened. In other words, the time available for sending and receiving data by the second communication operation becomes longer. As a result, it is possible to further suppress a decrease in the throughput of data transmission / reception due to the second communication operation. That is, in the present embodiment, the change in the number of channels to be scanned in one scanning operation is also included in the load reducing operation in the second communication operation. When reducing the number of channels to be scanned, it is desirable to shift the channels to be scanned for each scanning operation. By repeating such a scanning operation a plurality of times, all channels can be scanned as a result.

Further, the control circuit 13 reduces the transmission frequency of the ACK (affirmative response) transmitted by the second communication circuit 12 (step S207). That is, the control circuit 13 sets the transmission frequency of ACK to a frequency lower than the initial state (default value). Specifically, the control circuit 13 enables the setting of the block ACK. As a result, the second communication circuit 12 returns one block ACK to the plurality of data, so that the transmission frequency of the ACK decreases, and the ACK transmission time in the cycle T (the time required to transmit the ACK). ) Becomes shorter. In other words, the time available for sending and receiving data by the second communication operation becomes longer. As a result, it is possible to further suppress a decrease in the throughput of data transmission / reception due to the second communication operation. That is, in the present embodiment, the change in the transmission frequency of the ACK is also included in the load reduction operation in the second communication operation.

After that, the communication device 1 continues the communication operation under the above-mentioned conditions until the real-time operation is completed (step S204: NO).

When the real-time operation is completed (step S204: YES), the control circuit 13 returns the setting to the initial state (step S205). That is, the control circuit 13 sets the time allocation of the execution periods T1 and T2, the beacon interval BI, the number of scan channels, and the transmission frequency of ACK to default values. Then, the normal operation is started. After that, the communication device 1 continues the normal operation until the real-time operation starts again.

As described above, according to the present embodiment, when the first communication operation is a real-time operation, the control circuit 13 scans in one scanning operation according to the change in the time allocation of the execution periods T1 and T2. Change the number of channels to be used. As a result, it is possible to further suppress a decrease in the throughput of the second communication operation.

Further, according to the present embodiment, when the first communication operation is a real-time operation, the control circuit 13 changes the transmission frequency of the ACK according to the change in the time allocation of the execution periods T1 and T2. As a result, it is possible to further suppress a decrease in the throughput of the second communication operation.

In the present embodiment, the control circuit 13 can change only one of the beacon interval BI, the number of scan channels, and the transmission frequency of ACK at the start of real-time operation.

Further, the control circuit 13 may select a parameter to be changed at the start of the real-time operation according to the type of the first communication operation and the type of the second communication operation.

The present invention is not limited to the configurations shown here, such as combinations with other elements in the configurations and the like described in the above embodiments. These points can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

1: Communication device 2: Opposite terminal 3: Opposite terminal 11: First communication circuit 12: Second communication circuit 13: Control circuit 14: Antenna 15: Switch circuit

Claims (10)

A first communication circuit that executes the first communication operation according to the first wireless communication standard, and
A second communication circuit that executes a second communication operation according to a second wireless communication standard different from the first wireless communication standard, and
A control circuit that controls the first communication operation and the second communication operation,
With
The first communication circuit can execute a specific communication operation that requires real-time performance in the first communication operation.
The control circuit
The first communication circuit and the second communication circuit can be made to execute a coexistence operation in which the first communication operation and the second communication operation are alternately executed in a time division manner.
A communication device that changes the time allocation between the first communication operation and the second communication operation based on the presence or absence of the specific communication operation in the first communication operation when the coexistence operation is executed. The control circuit
The time allocation is changed so that the ratio of the execution period of the first communication operation to the execution period of the second communication operation becomes longer than the initial state in accordance with the start of the specific communication operation.
The communication device according to claim 1, wherein the time allocation is returned to the initial state at the end of the specific communication operation. The control circuit
The time allocation is changed and the time allocation is changed according to the start of the specific communication operation.
In accordance with the change in the time allocation, the load reduction operation for reducing the communication load in the second communication operation is executed.
The communication device according to claim 2, wherein the load reduction operation is stopped at the end of the specific communication operation. The communication device according to claim 3, wherein the specific communication operation is a communication operation corresponding to stream distribution or voice call. The second communication circuit can execute a scanning operation using a beacon signal in the second communication operation.
The communication device according to claim 3 or 4, wherein the load reducing operation includes an operation of making the transmission interval of the beacon signal transmitted in the scanning operation longer than the initial state. The second communication circuit can execute a scanning operation using a beacon signal in the second communication operation.
The communication device according to any one of claims 3 to 5, wherein the load reducing operation includes an operation of reducing the number of channels to be scanned in one scanning operation from the initial state. The second communication circuit can transmit an acknowledgment corresponding to the received data in the second communication operation.
The communication device according to any one of claims 3 to 6, wherein the load reduction operation includes an operation of lowering the transmission frequency of an acknowledgment from the initial state. A first communication circuit that executes the first communication operation according to the first wireless communication standard, and
A second communication circuit that executes a second communication operation according to a second wireless communication standard different from the first wireless communication standard, and
A control circuit that controls the first communication operation and the second communication operation,
It is a communication method of a communication device equipped with
The first communication circuit can execute a specific communication operation that requires real-time performance in the first communication operation.
The control circuit
The first communication circuit and the second communication circuit can be made to execute a coexistence operation in which the first communication operation and the second communication operation are alternately executed in a time division manner.
A communication method that changes the time allocation between the first communication operation and the second communication operation based on the presence or absence of the specific communication operation in the first communication operation when the coexistence operation is executed. The control circuit
The time allocation is changed so that the ratio of the execution period of the first communication operation to the execution period of the second communication operation becomes longer than the initial state in accordance with the start of the specific communication operation.
The communication method according to claim 8, wherein the time allocation is returned to the initial state at the end of the specific communication operation. The control circuit
The time allocation is changed and the time allocation is changed according to the start of the specific communication operation.
In accordance with the change in the time allocation, the load reduction operation for reducing the communication load in the second communication operation is executed.
The communication method according to claim 9, wherein the load reduction operation is stopped at the end of the specific communication operation.

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