JP2006025130A - Communication device and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radio communication technology which makes shortening of a connection time compatible with reduction of power consumption. <P>SOLUTION: A radio device which realizes communication with a host device by responding to at least one of a device retrieval signal and a device connection request signal sent from the host device is equipped with a low-speed responding means 311 of responding at low speed to the device retrieval signal, a high-speed responding means 312 of responding at high speed to the device retrieval signal, and a control means 301 of switching the low-speed responding and high-speed responding according to specified conditions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

Conventionally, in wireless information communication, a technique is known in which a device search signal or a device connection request signal is issued from the master side in order to search for a responding device, and the slave side responds thereto. As an example, Bluetooth has proposed a method of switching operations such as an inquiry scan for waiting for an inquiry signal for searching for peripheral devices and a page scan for waiting for a page signal for calling. And as the latest of such wireless communication technology, Patent Document 1 discloses a method for shortening the connection time. In this method, the device that has received the inquiry signal continuously executes page scans, thereby speeding up the response to the page signal after completion of the inquiry.
JP 2003-32737 A

  However, in the above conventional technique, there is a problem that power consumption increases when a signal from the master is scanned at high speed in order to shorten the connection time. In other words, there has been no technology that achieves both reduction in connection time and reduction in power consumption.

  In order to solve the above-described problems, an object of the present invention is to provide a technique that achieves both a reduction in connection time and a reduction in power consumption in a communication technique.

A device that realizes communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from the host device,
Low-speed response means for making a low-speed response to the device search signal;
High-speed response means for making a high-speed response to the device search signal;
Control means for switching between the low-speed response and the high-speed response according to a predetermined condition;
It is characterized by providing.

A device that realizes communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from the host device,
Low-speed response means for making a low-speed response to the device connection request signal;
High-speed response means for making a high-speed response to the device connection request signal;
Control means for switching between the low-speed response and the high-speed response according to a predetermined condition;
It is characterized by providing.

In order to achieve the above object, the method according to the present invention comprises:
A device control method for realizing communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from a host device, wherein the device is slower than the device search signal. It can be driven in either a slow response mode that responds or a fast response mode that responds quickly to the device search signal,
The low-speed response and the high-speed response are switched according to a predetermined condition.

A device control method for realizing communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from a host device,
The device can be driven in either a low-speed response mode that responds to the device connection request signal at a low speed or a high-speed response mode that responds at a high speed to the device connection request signal.
The low-speed response and the high-speed response are switched according to a predetermined condition.

  In order to achieve the above object, a program according to the present invention is a program for causing the device to execute the control method.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which makes compatible shortening of connection time and reduction of power consumption can be provided in a communication technique.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the constituent elements described in this embodiment are merely examples, and are not intended to limit the scope of the present invention only to them.

  FIG. 2 shows the overall configuration of a Bluetooth communication system according to an embodiment of the present invention. The master 201 is a side that executes a peripheral device search, and transmits an inquiry signal that is a device search signal. In addition, it is a side that calls and connects the slave, and transmits a page signal that is a device connection request signal. The slave 202 is a side that searches for peripheral devices, and executes an inquiry scan at a cycle of 2.56 seconds. The page receiving side executes page scans at a cycle of 1.28 seconds.

  FIG. 3A is a diagram showing the internal configuration of both the master 201 and the slave 202. The host CPU 301 controls the entire device and is connected to the controller 302 through an HCI (Host Control Interface), and issues commands to the controller 302, transmits data, receives events, and receives data. The controller 302 plays a role of link control in the wireless connection section and an interface with the host CPU 301. A baseband (BB) unit 303 creates a wireless packet, calculates a hop channel used in the wireless section, creates a transmission timing in accordance with an instruction from the controller 302, and transmits the packet to an RF (Radio Frequency) unit. In addition, a frequency channel and timing received by the RF unit are created, and a wireless packet received from the RF unit is analyzed. The RF unit 304 modulates the packet received from the BB unit 303 with a 2.4 GHz carrier wave, and transmits it to the space via the antenna 304 at the timing and frequency channel specified by the BB unit 303. Further, after synchronizing the packet of the RF signal received by the antenna 305, it is demodulated into a baseband signal and passed to the BB unit 303. Transmission and reception are switched in a time division manner. The antenna 305 radiates and receives an RF signal to space.

  FIG. 4 shows a timing relationship between an inquiry scan, which is one of the reception operations performed by the slave 202, and an inquiry signal transmitted by the master 201. In 2.56 seconds, the master repeatedly transmits up to f (a16) 256 times while changing the inquiry signal in order of frequencies f (a1), f (a2), and f (a3) in a short cycle. In the next 2.56 seconds, transmission in sequence from the frequency f (b1) to f (b16) is repeated 256 times. After a total of 5.12 seconds, the inquiry signal transmission is stopped.

  The slave performs a reception waiting operation (scan) for 11.25 ms while changing the frequency channel every other f (a2) and f (a4) every 2.56 seconds. When scanning to f (a16), every other scanning from f (b2) to f (b16) is performed, and the processing returns to f (a2) again.

  Therefore, in the case of this figure, the inquiry signal transmitted by the master at the two locations indicated by the coincidence matches the inquiry scan frequency of the slave, and the slave can receive the inquiry signal from the master once in 5.12 seconds. It is. In this case, the slave 202 shows a case where the interlace scan is OFF. In the case of a page signal and page scan, the transmission and reception periods are halved to 1.26 seconds.

  FIG. 5 shows a timing relationship between an inquiry interlace scan which is one of the reception operations performed by the slave 202 and which responds to the device search signal at a high speed, and an inquiry signal transmitted by the master 201. The contents transmitted by the master are the same as in FIG.

  The slave scans f (b2) for 11.25 ms every 2.56 seconds after scanning f (a2) for 11.25 ms. Next, scan f (a4) and f (b4) at a period of 2.56 seconds. In this way, the slave scan in FIG. 4 is different in that another series of channels is scanned within a scan period of 2.56 seconds.

  Therefore, in the case of this figure, the inquiry signal transmitted by the master at the two locations indicated by the coincidence matches the inquiry scan frequency of the slave, and the slave can receive the inquiry signal from the master once in 2.56 seconds. It is. In this case, the slave 202 shows a case where the interlace scan is ON. In the case of a page signal and page interlace scan, the transmission and reception periods are halved to 1.26 seconds.

  Next, functional configurations of the controller 302 and the CPU 303 of this system will be described with reference to FIG. 3B.

  FIG. 3B shows the module that is called in the flowchart description. Reference numeral 311 denotes a low-speed inquiry scan module as a low-speed response means for scanning an inquiry signal as a device search signal at a low speed. Reference numeral 312 denotes a high-speed inquiry scan module as a high-speed response means for scanning an inquiry signal by interlace. Reference numeral 313 denotes a low-speed page scan module as low-speed response means for scanning a page signal as a device connection request signal at low speed. Further, reference numeral 314 denotes a high-speed page scan module as high-speed response means for scanning a page signal by interlace. Each scan module is selectively executed by an instruction from the CPU 301 as a control unit that switches between a low-speed response and the high-speed response.

  Next, the operation of this system will be described using the flowchart of FIG. 1A.

  The power of the slave 202 is turned on (S101). After the power is turned on, the CPU 301 of the slave 202 notifies the controller 302 of an inquiry interlace scan start command and a page interlace scan start command which is a scan process for responding to a device connection request at high speed. The controller 302 receives the start command and instructs the BB unit to start scanning. The BB unit 303 calculates a frequency hopping channel from the address of the slave 202 and the clock information, and notifies the RF unit 304 of the reception timing and reception frequency. The RF unit 304 starts an inquiry interlaced scan and a page interlaced scan as shown in the slave (RX) in FIG. 5 (S102).

  When the BB unit 303 receives the inquiry signal from the master 201 via the RF unit 304, the BB unit 303 creates an FHS packet to which the address notified from the controller 302 and clock information are added, and the RF unit 304, the inquiry response is transmitted to the master via the antenna 305 (S103). At the same time, the controller 302 of the slave 202 receives the FHS packet transmission and instructs the BB unit 303 to stop the inquiry interlace scan and the page interlace scan. In response to the instruction, the BB unit 303 stops interlace scanning with respect to the RF unit 304, and switches between normal inquiry scan and page scan as shown in FIG. 4 (S105). This is because there is a high possibility that a connection request such as a name request or a service request will come after the inquiry signal from the master, and the slave address and clock information are notified to the master 201 as an inquiry response. This is because even if a race page scan is performed, the effect of shortening the connection time cannot be expected. At this time, by stopping the interlaced scan, the scan time is halved, thereby reducing power consumption.

  If no inquiry signal is received in step S103, confirmation of page signal reception is performed (S104). If the page signal is not received by the BB unit 304, the process returns to step S103, and an inquiry signal confirmation operation is performed.

  When the BB unit 304 confirms reception of the page signal, the controller 302 starts a series of connection procedures. After the connection, when the controller 302 receives a name request from the master 201, the controller 302 creates a packet including the slave name at the BB 303, notifies the master 201 via the RF 304 and the antenna 305, and performs a disconnection process. . When the controller 302 receives a service request from the master 201, the controller 302 notifies the CPU 301 of the service request and obtains a service information packet from the CPU 301. The obtained service information packet is converted into a wireless packet at the BB 303 and notified to the master 201 via the RF unit 304 and the antenna 305, and then the disconnection process is performed. In addition, in the case of a connection request, the connection state is maintained, and in any case, the interlace scan is stopped in step S105.

  Next, the controller 302 of the slave 202 determines whether or not a predetermined time has elapsed since the time stopped in step S105 (S106). After a predetermined time has elapsed, the controller 302 determines whether it is connected to the master 201 (S107). If there is a connected device, the interlace scan stop is continued to secure a communication band with the connected device. If there is no connected device, the process returns to step S102, and the interlace scan is started again.

  According to the operation as described above, when an inquiry or page signal is received, it is possible to suppress unnecessary power consumption by stopping the interlace scan and to secure a communication band with the connected device. Become.

  Other operations that can be executed in this system will be described with reference to FIG. 1B.

  As shown in FIG. 1B, after receiving the inquiry signal in step S103, the inquiry interlace scan is stopped, and a normal low-speed inquiry scan is started (S105a). In addition, after receiving the page signal in step S104, it is possible to stop the page interlace scan and start a normal low-speed page scan (S105b).

  In these embodiments, after the power is turned on after the start, both the inquiry scan and the page scan are interlaced. However, only one of them may be interlaced.

  Further, in the configuration of FIG. 1B, after the inquiry signal is received, the inquiry scan is set to a low speed. However, only the page scan may be set to a low speed scan here. Similarly, after the page signal is received, only the inquiry scan is set to a low speed. May be.

  In this embodiment, the controller 302 determines that the interlace scan is stopped, but the CPU 301 may determine it. Further, the controller 302 can substitute the function of the CPU 301 in a small device. It is also possible to select the interlace scan to be stopped as appropriate. For example, after receiving an inquiry signal when searching for a device, the interlace operation of only the interlaced page scan is stopped to maintain a high-speed response to the inquiry signal from another device. It is also conceivable to configure so as to stop. Alternatively, the interlace scan is stopped when the traffic monitoring function (not shown) detects that the communication traffic exceeds a certain level, and the interlace scan is started when the traffic decreases. It is also possible. Further, the power supply monitoring function (not shown) may be configured to stop the interlace scan when the slave 302 is driven by the battery and start the interlace scan when the slave 302 is driven by the AC power supply. Furthermore, when the remaining battery level falls below a certain level, the interlace scan can be stopped and the normal scan can be performed by the power supply monitoring function. As the processing related to the power source, it is included in the present invention that both the inquiry scan and the page scan can be slowed down or only one of them can be slowed down.

  As described above, response to peripheral device search and connection time from the pairing device are shortened after power-on, reducing power consumption during device acquisition and service acquisition operations after peripheral device search, and communication When there is a lot of traffic or when there is a lot of traffic, the throughput can be improved by shortening the scan time. Furthermore, when the battery is used or when the remaining battery level is low, it is possible to suppress battery consumption.

(Other embodiments)
Although the embodiments of the present invention have been described in detail above, the present invention may be applied to a system constituted by a plurality of devices or may be applied to an apparatus constituted by one device.

  The present invention can also be achieved by supplying a program that realizes the functions of the above-described embodiments directly or remotely to a system or apparatus, and the system or apparatus reads and executes the supplied program code. The Accordingly, the program code itself installed in the computer in order to realize the functional processing of the present invention by the computer is also included in the technical scope of the present invention.

  In this case, the program may be in any form as long as it has a program function, such as an object code, a program executed by an interpreter, or script data supplied to the OS.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program itself of the present invention or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the claims of the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on an instruction of the program is a part of the actual processing. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a flowchart which shows the operation | movement in the radio | wireless system as embodiment of this invention. It is a flowchart regarding the other operation | movement in the radio | wireless system as embodiment of this invention. It is a block diagram of the radio | wireless system as embodiment of this invention. It is an internal block diagram of a master and a slave as an embodiment of the present invention. It is a functional block diagram of the radio | wireless system as embodiment of invention. It is a figure which shows the normal scan timing in the radio | wireless system as embodiment of this invention. It is a figure which shows the high-speed scan timing in the radio | wireless system as embodiment of this invention.

Explanation of symbols

201 ... Master 202 ... Slave 301 ... CPU
302 ... Controller 303 ... BB unit 304 ... RF unit

Claims (10)

A device that realizes communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from the host device,
Low-speed response means for making a low-speed response to the device search signal;
High-speed response means for making a high-speed response to the device search signal;
Control means for switching between the low-speed response and the high-speed response according to a predetermined condition;
A device comprising: A device that realizes communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from the host device,
Low-speed response means for making a low-speed response to the device connection request signal;
High-speed response means for making a high-speed response to the device connection request signal;
Control means for switching between the low-speed response and the high-speed response according to a predetermined condition;
A device comprising:   The device according to claim 1, wherein the control unit performs the low-speed response after responding to either the device search signal or the device connection request signal.   The device according to claim 1, wherein the control unit performs the low-speed response when the device is connected to another device.   The said control means performs the said low-speed response, when the said device is connecting with another device and the communication load between the devices is more than predetermined value, The said low speed response is characterized by the above-mentioned. The device described.   6. The device according to claim 1, wherein the control means performs the low-speed response when the device is battery-powered.   The device according to claim 1, wherein the control unit performs the low-speed response when a remaining battery level of the device is equal to or less than a predetermined value. A device control method for realizing communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from a host device, wherein the device is slower than the device search signal. It can be driven in either a slow response mode that responds or a fast response mode that responds quickly to the device search signal,
A device control method, wherein the low-speed response and the high-speed response are switched according to a predetermined condition. A device control method for realizing communication with a host device by responding to at least one of a device search signal and a device connection request signal transmitted from a host device,
The device can be driven in either a low-speed response mode that responds to the device connection request signal at a low speed or a high-speed response mode that responds at a high speed to the device connection request signal.
A device control method, wherein the low-speed response and the high-speed response are switched according to a predetermined condition.   A program for causing the device to execute the control method according to claim 8 or 9.

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