JP2002152309A - Bluetooth apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Bluetooth (R) apparatus which is capable of saving electric power when data communication is not maintained, establishing a link in a shorter time, and protecting a logic link against disconnection near a critical communication range in which communication can be maintained. SOLUTION: A Bluetooth (R) apparatus 11 is composed of a radio communication unit 12 which makes radio communication, a link control unit 13 which controls the connection/cutoff of a physical link for the radio communication unit 12, and an application unit 14 which includes the upper layer of a Bluetooth (R) protocol stack and a man-machine interface. The link control unit 13 makes the radio communication unit 12 cut off the physical link and the application unit 14 hold a logic link when the data communication is not maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable information terminal, a portable telephone, and a personal computer.
Bluetooth that performs wireless communication in accordance with the th protocol
th device.

[0002]

2. Description of the Related Art Conventionally, a multi-channel access system (M
In wireless devices having the (CA system), an intermittent reception system in which a reception side is set to a reception mode intermittently at a constant cycle is often used for power saving. That is, power for operation is supplied to the receiving unit at a certain time interval, and the receiving operation is performed intermittently with a predetermined pause. Further, JP-A-8-2
In Japanese Patent No. 65823, the channel scanned by the receiving side during intermittent reception is limited to a channel group determined by the transmitting side and the receiving side, thereby shortening the time of the receiving mode of the receiving side and promoting power saving. I have. On the other hand, Bluetooth also has a park mode for performing power saving operations. When the physical link is established, the master and the slave synchronize at a predetermined timing even if data transmission and reception are not performed. Then, when synchronization cannot be established, the physical link is disconnected.

[0003]

In the park mode, since the master and the slave maintain the physical link in synchronization with each other at a predetermined timing, the master and the slave can quickly return to the active state in which data communication is possible. However, even though it is in the power saving mode, as long as synchronization is performed periodically, power is consumed more than in a state where no link is connected. On the other hand, when connecting the link between the master and the slave from the beginning, in addition to the connection of the physical link, Bluetooth
Establishing a logical link of each layer of the "oth" protocol is necessary, and it takes time to start data communication. On the other hand, there is a limit to the distance over which a Bluetooth device can communicate, and a physical link is liable to be disconnected near the limit distance, and is interrupted even during data communication.

[0004] The present invention eliminates the above-mentioned problems, and can reduce power consumption when data communication is not performed, and can shorten the time required for link establishment.
It is an object of the present invention to provide a Bluetooth device in which a logical link is hardly disconnected near a limit of a communicable distance.

[0005]

A first aspect of the present invention is a Bluetooth device having an application capable of communicating with each other.
h device, a wireless communication unit for wirelessly transmitting and receiving data, and link control for controlling the wireless communication unit to establish a physical link and provide a logical link to an upper layer on a protocol stack And an application unit including a user interface and an upper layer of the Bluetooth protocol. When data communication is not performed after a logical link is connected between the application units, the link control unit transmits a request from the application unit. , The physical link is automatically disconnected and the logical link is maintained.

According to a second aspect of the present invention, in the Bluetooth device, the link control unit includes a partner Bluetooth device.
If there is a response from the th device, the partner Bl
Continue to contact the Bluetooth device, Bluetooth partner
When there is no response from the tooth device, the logical link is disconnected.

According to a third aspect of the present invention, in the Bluetooth device, the link control section includes a partner Bluetooth device.
When detecting that the th device has deviated from the communicable distance, an inquiry is further made a predetermined number of times, the logical link is kept held when there is a response, and the logical link is disconnected when there is no response. And

According to a fourth aspect of the present invention, in the Bluetooth device, the link control unit holds the logical link when receiving a link disconnection notification due to the other Bluetooth device being out of the communicable distance during the asynchronous data communication. Asynchronous data communication is temporarily interrupted by applying flow control to the application section while the communication is being performed, and an inquiry is made a predetermined number of times. When a response is received from the partner Bluetooth device, the physical link is connected again to resume the asynchronous data communication. When there is no response, the logical link is disconnected.

A fifth aspect of the present invention relates to a Bluetooth device in which applications capable of communicating with each other are mounted.
A wireless communication unit for transmitting and receiving data wirelessly, a link control unit for controlling the wireless communication unit to construct a physical link and provide a logical link to an upper layer on a protocol stack, User interface and Blue
An application unit including an upper layer of the tooth protocol, a microphone for inputting audio, a speaker for outputting audio, a PCM codec unit having an audio codec and a function of outputting arbitrary sound, The link control unit controls the other party's Bluetooth during voice communication.
When a link disconnection notification is received due to the device being out of the communicable distance, an inquiry is made a predetermined number of times, and during that time, a sound is generated in the PCM codec unit and generated by the speaker, and the physical link is being reconnected. When a response is received from the partner Bluetooth device, the physical link is connected again to resume voice communication, and when there is no response, the logical link is disconnected.

In the present invention, first, in power saving, the presence or absence of data communication is checked, and when data communication is not performed, the physical link is disconnected while the logical link is maintained. During this time, an inquiry is periodically made in order to confirm whether or not the other device is within the communicable distance. In this case, the period for making an inquiry is longer than the period for synchronizing the master and the slave in the park mode. If there is no response to the inquiry, the logical link is disconnected. If data communication is started in that state, it is detected and a physical link is connected.

In this way, by cutting off the physical link when data communication is not being performed, there is no need to perform wireless communication, and power is not consumed accordingly. Further, by maintaining the logical link, only the connection of the physical link may be performed when data communication is started again,
Since the exchange of a link establishment request and a negotiation message in establishing a logical link can be omitted, the reconnection time can be reduced.

On the other hand, when the physical link is disconnected while maintaining the logical link, periodic inquiry is made to the partner device, so that it is possible to early detect that the communication distance has been deviated.

By continuing inquiry for a predetermined time when it is detected that the communication distance is out of the communicable distance, it is possible to keep the logical link even when entering or leaving the communicable distance.

[0014] Further, when it is detected that the communication distance is out of the communicable distance during the asynchronous data communication, the application section is subjected to flow control to temporarily suspend data transmission. Communication can be resumed.

Further, when it is detected that the communication distance is out of the communicable range during the voice communication, the PCM codec generates a reconnecting sound and generates the sound at the speaker, whereby the physical link is interrupted and the voice communication is interrupted. And that the physical link is being reconnected.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a Bluetooth device according to the present invention.
FIG. 3 is a block diagram illustrating an embodiment of an oth device. Bl
The Bluetooth device 11 includes a wireless communication unit 12 that performs wireless communication, a link control unit 13 that controls connection / disconnection of a physical link to the wireless communication unit, an upper layer of a Bluetooth protocol stack, a man-machine interface, and the like. It consists of an application section.

FIGS. 2 to 5 are flowcharts showing the processing of the link control unit 13 in the Bluetooth device. Normally, the physical link is connected under the control of the link control unit 13, and then the logical link of the application unit is established, and the link control unit 13 holds information on the correspondence between the physical link and the logical link. On the other hand, Bl
The ethno link includes an asynchronous connectionless ACL link and a synchronous connection-oriented link S.
There is a CO link. Asynchronous data communication is performed through the ACL link, and synchronous data communication is performed through the SCO link. Of these, the SCO link is used for transmitting voice due to its characteristics, and connection / disconnection control is performed by the link control unit 13, but actual data is directly converted to hardware by PCM.
Since the codec is passed from the codec to the wireless communication unit 12, the link control unit 13 cannot determine whether data communication is being performed.

Therefore, as shown in FIG. 2, first, the link control unit 13 determines whether or not an ACL link for performing data communication through the link control unit 13 is performing data communication (S21). At this time, since each data is divided into packets and transmitted / received, the timer is started each time each packet is transmitted / received (if necessary, the previously started timer is canceled), and the timer has expired. It is necessary to determine that data communication is not in progress.

Next, regarding the SCO link, as described above, the SC
The link control unit 1 determines whether data communication is being performed on the O link.
3, the link control unit 13 identifies whether the link is in a connected state or a disconnected state (S2).
2). After passing S21 and S22, the link control unit 1
3 transmits a link disconnection request to the wireless communication unit 12 (S23). At this time, the link control unit 13 does not discard the information for managing the correspondence between the physical link and the logical link, and changes only the flag indicating the connection state of the physical link.

In this way, by disconnecting the physical link, there is no need to perform wireless communication from the wireless communication unit 12,
It does not need to consume power. In addition, by continuing to hold the logical link, when data communication is started again, the link control unit 13 only needs to connect the physical link, and transmits a link establishment request or a negotiation message in establishing the logical link. Since the exchange can be omitted, the reconnection time can be reduced.

Next, as shown in FIG.
3 starts a timer when the physical link is disconnected while maintaining the logical link (S4).
1). When the timer has expired (S42), the Bluetooth device that was the master when the physical link was connected makes an Inquiry request, and the Bluetooth device that was the slave
Inquiry scan is performed in the Bluetooth device (S43). By setting the time for each operation to be longer, the error of the timer between the Bluetooth devices can be absorbed. The result is identified (S44). If there is a response, the timer is started again (S41). If there is no response, a disconnection notification is sent to the application unit 14 in the same manner as when a link disconnection request is received from the partner. Then, the logical link is disconnected (S45).

In this way, the link control unit 13 sets the timer for a predetermined time as long as there is a response while disconnecting the physical link while holding the logical link. Perform a query or query scan. In this manner, by repeatedly inquiring periodically and determining whether there is a response, it is possible to immediately detect that the partner Bluetooth device has deviated from the communicable distance.

FIG. 4 shows another example in which the physical link is disconnected while the logical link is maintained. The counter is reset (S51), and when the inquiry is made as described above (S52 to S55), if there is no response, the counter is incremented (S5).
6). Next, the value of the counter is checked, and if it exceeds a certain value (S57), a disconnection notification is sent to the application unit 14 to perform a logical link disconnection process as in the case where a link disconnection request is received from the partner (S58). . If the value of the counter does not exceed the certain value, an inquiry is made again (S52).
To S55). If there is a response when the inquiry is made again, the counter is reset (S51), and the inquiry process is continued (S52 to S55).

In this way, the link establishment control unit 13 does not disconnect the logical link when detecting that the other device has deviated from the communicable distance, and continues to inquire for a predetermined time, thereby entering and exiting the communicable distance. In such a case, the logical link can be maintained. Thus, when the partner device comes within the communicable distance, a link can be immediately established, and the reconnection time can be reduced.

Next, processing when a link disconnection notification is received during asynchronous data communication will be described. As shown in FIG. 5, when the link disconnection notification is received due to the excessive separation of two Bluetooth devices during the asynchronous data communication (S61), a flow OFF message is notified to the application unit 14 to perform the asynchronous data communication. Is interrupted (S62). The counter is reset (S63),
An inquiry is attempted a fixed number of times (S64 to S67). If there is no response to all inquiries, the logical link is disconnected (S68). If there is a response, a physical link connection process is performed (S69), a flow ON message is notified to the application unit 14 (S70), and the asynchronous data communication is resumed.

As described above, when it is detected that the communication distance is deviated from the communicable distance during the asynchronous data communication, the data transmission is temporarily suspended by applying the flow control to the application unit without completely disconnecting the logical link. As a result, when the physical link is connected again, the logical link is in the connected state, so that the data communication can be immediately resumed.

FIG. 6 is a block diagram showing another embodiment of the Bluetooth device according to the present invention. This Blu
The Bluetooth device includes, in addition to the Bluetooth device of FIG. 1, a PCM codec unit 15 having a voice codec and a function of outputting an arbitrary voice, a microphone 16 for inputting voice, and a speaker 17 for outputting voice. It has.

FIG. 7 is a flowchart showing the processing of the link control unit 13 in the Bluetooth device. Two Bluetooth during voice communication on SCO link
If the link disconnection notification is received due to excessive separation of the other device (S71), the PCM codec unit 15
Is controlled to emit a sound generated during the reconnection arbitrarily determined (S72), the counter is reset (S73),
An inquiry is attempted a certain number of times (S74 to S77). If there is no response to all the inquiries, the reconnection sound is stopped (S78), and the logical link is disconnected (S79).
If there is a response, a physical link connection process is performed (S8).
0), the sound during reconnection is stopped (S81), and voice communication is resumed.

In this way, the PCM codec unit 15 generates a reconnecting sound and generates the sound at the speaker 17 when it is detected that the communication distance is out of the communicable distance during the voice communication, so that the physical link is broken and the voice communication is interrupted. And that the physical link is being reconnected. As described above, by notifying the operator of the link connection status by the sound, the status can be easily grasped, and an accurate judgment can be made.

[0030]

As described above, according to the first aspect, it is not necessary to perform wireless communication by disconnecting a physical link when data communication is not being performed, so that power consumption is not required. . Further, by maintaining the logical link, only the physical link needs to be connected when data communication is started again, and the exchange of a link establishment request and a negotiation message in establishing the logical link can be omitted. Connection time can be reduced.

According to the second aspect of the present invention, when the physical link is disconnected while the logical link is held, the other device is periodically inquired to prevent the device from being out of the communicable distance. Can be detected early.

According to the third aspect of the present invention, the inquiry is continued for a predetermined time when it is detected that the communication distance is out of the communicable distance. You can keep holding.

Further, according to the fourth aspect, when it is detected that the communication distance is deviated from the communicable distance during the asynchronous data communication, the application section is subjected to flow control to temporarily suspend the data transmission, thereby re-establishing the physical link again. Can be resumed when is connected.

Further, according to the fifth invention, when it is detected that the communication distance is out of the communicable distance during the voice communication, the PCM codec generates a sound during reconnection and generates the sound at the speaker, thereby disconnecting the physical link. Thus, it can be shown that the voice communication is interrupted and the physical link is being reconnected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a Bluetooth device according to the present invention.

FIG. 2 is a flowchart illustrating processing of a link control unit.

FIG. 3 is a flowchart illustrating another process of the link control unit.

FIG. 4 is a flowchart illustrating another process of the link control unit.

FIG. 5 is a flowchart illustrating another process of the link control unit.

FIG. 6 is a block diagram showing another embodiment of a Bluetooth device according to the present invention.

FIG. 7 is a flowchart illustrating another process of the link control unit.

[Explanation of symbols]

 11 Bluetooth device 12 Wireless communication unit 13 Link control unit 14 Application unit 15 PCM codec unit 16 Microphone 17 Speaker

Claims (5)

[Claims] 1. A Bluetooth device equipped with an application capable of communicating with each other, comprising: a wireless communication unit for transmitting and receiving data wirelessly; and a physical link constructed by controlling the wireless communication unit to form a higher-level protocol stack. A link control unit for providing a logical link to a layer; and an application unit including an upper layer of a user interface and a Bluetooth protocol, wherein data communication is not performed between the application units after a logical link is connected. A Bluetooth device, wherein the link control unit automatically disconnects a physical link without depending on a request from the application unit, and retains a logical link. 2. The link control unit according to claim 1, further comprising:
If there is a response from the other device, the partner B
Continue to contact the Bluetooth device, Bluetooth partner
2. The Bluetooth according to claim 1, wherein the logical link is disconnected when there is no response from the Bluetooth device.
oot equipment. 3. The link control unit according to claim 1, wherein
When the other device detects that the device is out of the communicable distance, it makes an inquiry a predetermined number of times, keeps holding the logical link when there is a response, and disconnects the logical link when there is no response. Claim 1
The Bluetooth device as described. 4. When the link control unit receives a link disconnection notification due to the fact that the partner Bluetooth device is out of the communicable distance during asynchronous data communication, the link control unit performs flow control on the application unit while maintaining the logical link. , The asynchronous data communication is temporarily interrupted, an inquiry is made a predetermined number of times, and when a response is received from the partner Bluetooth device, the physical link is connected again to resume the asynchronous data communication, and when there is no response, the logical link is 2. The Bl according to claim 1, wherein
Bluetooth equipment. 5. A Bluetooth device equipped with an application capable of communicating with each other, a wireless communication unit for wirelessly transmitting and receiving data, and a physical link controlled by controlling the wireless communication unit to form a physical link on a protocol stack. A link control unit for providing a logical link to an upper layer, an application unit including an upper layer of a user interface or a Bluetooth protocol, a microphone for inputting audio, and a speaker for outputting audio. PCM with audio codec and function to emit any sound
A codec unit, wherein the link control unit is configured to communicate with the partner Bluetooth during voice communication.
When a link disconnection notification is received that the th device is out of the communicable distance, an inquiry is made a predetermined number of times,
In the meantime, a sound is generated in the PCM codec unit and generated by the speaker to indicate that the physical link is being reconnected, and when a response is received from the partner Bluetooth device, the physical link is connected again to resume voice communication. A Bluetooth device that disconnects a logical link when there is no response.