JP2006180421A - Wireless communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit digital data from slave modules to a master module in the middle of communication of audio signal only using all available SCO links between the master module and a plurality of the slave modules. <P>SOLUTION: While only audio signals are communicated between the master modules and the plurality of slave modules using all the available SCO links, the master module transmits a DV packet indicating that the DV packet is the alternative packet of a Null or Poll packet, in a fixed cycle. A slave module that receives the DV packet, executes transmission of digital data to be executed when the Null packet or the Poll packet is received, namely, executes transmission processing of the DV packet containing audio and data. Thus, digital data can be transmitted from the slave modules to the master module. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication method, and in particular, one of Bluetooth modules that communicate with each other is a master module, and the other module is a slave module, so that only real-time data such as audio signals can be communicated between them. The present invention relates to a communication method that makes it possible to perform digital data communication in the middle of performing.

  Bluetooth modules generally process RF transceiver ICs, baseband ICs, digital data, etc., and also control DSPs for the entire module, real-time properties such as HCI, which is a communication interface to protocols for managing wireless links, and voice It is configured to include a synchronization channel called SCO used for an application that requires the. The Bluetooth module can perform audio signal communication, digital data communication, and communication in which these are mixed with one or more other Bluetooth modules.

  When one of the Bluetooth modules that communicate with each other is a master module and the other Bluetooth module is a slave module and digital data communication (ACL communication) is performed between the master module and the slave module, Data transmission can be performed at any timing, but data transmission from the slave module to the master module can be performed only when the slave module receives a null packet or a poll packet transmitted from the master module. Can be done as a response.

  In addition, when trying to perform only voice communication (SCO communication) between the master module and the slave module, communication is performed by establishing a link called an SCO link between the master module and the slave module. A maximum of three SCO links can be installed at the same time. In this case, voice communication can be performed between one master module and one slave module using three SCO links. It is also possible to perform voice communication using the SCO link. When three SCO links are established from the master module, all communication bands between the Bluetooth modules are occupied.

  2 is a diagram for explaining the outline of communication using the SCO link between the master module and the slave module, and FIG. 3 is a diagram for explaining the use of the slots of the three SCO links. A voice signal communication method using the SCO link in the case of the prior art will be described with reference to FIG.

  The example shown in FIG. 2A is an example in which communication is performed using three SCO links between one master module (denoted as M) and one slave module (denoted as S). Since two SCO links are used simultaneously between the two parties, it is possible to transmit a wideband audio signal that cannot be transmitted with only one SCO link, music, etc. It is suitable for the case where it is desired to transmit a wide-band signal with high fidelity.

  For example, a technique described in Patent Document 1 is known as a conventional technique that enables transmission of a wideband audio signal using such three SCO links.

  In the example shown in FIG. 2B, communication is performed using one SCO link between one master module (denoted as M) and three slave modules (denoted as S). An example is shown. In this example, the master module can perform voice communication with three slave modules at the same time. However, since the band of the signal that can be transmitted by one SCO link is narrow, it is not a broadband signal such as music. This is suitable when it is desired to transmit voice or the like.

The signal transmission period T in one SCO link is determined by the Bluetooth standard. The example shown in FIG. 3 shows transmission / reception of signals when communication is performed using one SCO link between one master module and one slave module. As described above, , A maximum of three SCO links can be configured during the transmission period T, and these three SCO links can be used for all communication with one slave module, Can be used one by one for communication.
JP 2002-185559 A

  In the above-described voice signal communication method using the SCO link according to the prior art, when communication is performed using all three SCO links, all communication bands between the modules are occupied. In general, packets called HV1, HV2, and HV3 are defined as packets used in communication using the SCO link. As a state in which all communication bands between modules are occupied, (1) If there is one SCO link and the packet to be used is HV1, (2) two SCO links and the packet to be used is HV2, (3) three SCO links and the packet to be used is There are three cases of HV3. In the case of (1) described above, voice and data can be transmitted and received between modules using a DV packet capable of mixing data and voice. Also in the cases (2) and (3) described above, voice and data can be transmitted and received between modules using DV packets. However, since the data amount of DV packets is small, the voice quality deteriorates. Resulting in.

  When all the communication bandwidth between modules is occupied, digital data transmission from the master module to the slave module is a DV packet that can mix data and voice defined in the Bluetooth specification. It is possible to carry out by using. However, in such a case, the communication method according to the conventional technique cannot transmit a null packet or a poll packet from the master module, and as a result, cannot transmit digital data from the slave module to the master module. Cause problems.

  The object of the present invention is to solve the above-mentioned problems of the prior art, and during the communication of only the audio signal between all of the usable SCO links between the master module and the plurality of slave modules. Another object of the present invention is to provide a wireless communication method capable of transmitting digital data from a slave module to a master module.

  According to the present invention, in the wireless communication method between the master module and the plurality of slave modules, when the communication of only the audio signal is performed between the master module and the plurality of slave modules, It is determined that the master module transmits a DV packet at a constant cycle, and a slave module that receives the DV packet can execute a digital data transmission process that is executed when a null packet or a poll packet is received. Is achieved.

  Further, the object is that the master module and the slave module are Bluetooth modules, the communication of only the audio signal is communication by an SCO packet, and the digital data transmission processing can mix data and audio. This is achieved by communication using a simple DV packet.

  The object is achieved by indicating that the DV packet transmitted from the master module is a substitute packet for a Null or a Poll packet.

  Furthermore, the object is achieved by performing communication for transmitting DV packets at the fixed period when three SCO links for transmitting the SCO packet are established.

  According to the present invention, digital data from a slave module to a master module is communicated between a master module and a plurality of slave modules while only audio signals are being communicated using all available SCO links. You can send.

  Embodiments of a wireless communication method according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a wireless communication method according to an embodiment of the present invention, and the wireless communication method according to an embodiment of the present invention will be described with reference to FIG. The example shown in FIG. 1 shows the state of communication between one master module and three slave modules.

  As shown in FIG. 1, in the transmission cycle T defined by the Bluetooth standard, the master module establishes three SCO links and establishes SCO with each of the slave modules 1 to 3. It is assumed that communication of only an audio signal is started using a packet. The SCO packet used here is a packet called HV3 that can support three SCO links defined by the Bluetooth standard as described above. And in embodiment of this invention, when the master module starts communication only of an audio | voice signal, the packet called DV packet which can carry data and an audio | voice together is transmitted regularly. Then, the master module sets a code indicating that the packet is an alternative packet to the Null or Poll packet in the DV packet to be transmitted.

  On the other hand, it is indicated that the slave module is a substitute packet for the above-described Null or Poll packet even in a state where the Null packet or the Poll packet cannot be received by communication of only the audio signal using the SCO packet. When receiving a DV packet, it is determined that transmission of digital data executed when a Null packet or a Poll packet is received, that is, transmission processing of a DV packet including voice and data, can be executed. A DV packet is transmitted to the master module.

  The embodiment of the present invention shown in the example shown in FIG. 1 uses four periods T1 to T4 having a transmission period T defined by the above-described Bluetooth standard for communication of only an audio signal using an SCO packet, The next period T5 is used for DV packet transmission. Then, DV packets are transmitted at regular intervals such that four cycles are used for communication of only audio signals using SCO packets, and the next one cycle is used for transmission of DV packets.

  In the example shown in FIG. 1, the master module communicates with each other by using three SCO links, and therefore, the master module is different in the above-described cycle T5 and once every five cycles thereafter. Transmits a DV packet to each of the slave modules 1 to 3. Each of the slave modules 1 to 3 that has received this information can transmit a DV packet including voice and data to the master module as a response to the DV packet if there is digital data to be transmitted from the own module to the master module. it can. Each of the slave modules 1 to 3 responds with a normal SCO packet if there is no digital data to be transmitted from the own module to the master module.

  In the above-described embodiment of the present invention, since the slave modules with which the master module communicates using three SCO links are different from each other, the master module sends a DV packet to each of the slave modules 1 to 3. If the master module performs voice communication with only one slave module using SCO packets using three SCO links, the master module sends DV packets to only one SCO link. That's fine.

  In the above-described embodiment of the present invention, the master module transmits a DV packet to the slave module at a cycle of once every five times of the cycle T. Whether the DV packet is transmitted to the slave module in a cycle may be arbitrarily set. Further, in the above-described embodiment of the present invention, when the master module communicates with each other using three SCO links, each slave module transmits a DV packet to each different slave module in the same cycle. As described above, the cycle of transmitting the DV packet to each of the different slave modules can be arbitrarily set.

  According to the above-described embodiment of the present invention, when the master module performs communication of only the audio signal using all the available SCO links between the master module and one or more slave modules, Since a DV packet indicated to be a substitute packet for a Null or Poll packet is transmitted at a certain period, the slave module that has received this packet executes digital data that is executed when the Null packet or the Poll packet is received. Transmission, that is, ACL data transmission processing, and digital data can be transmitted from the slave module to the master module.

It is a figure explaining the radio | wireless communication method by one Embodiment of this invention. It is a figure explaining the outline of communication using the SCO link between a master module and a slave module. It is a figure explaining utilization of the slot of three SCO links.

Explanation of symbols

M Master module S Slave module

Claims (4)

  In the wireless communication method between a master module and a plurality of slave modules, when only the audio signal is communicated between the master module and the plurality of slave modules, the master module is A wireless communication method comprising: transmitting a DV packet, and determining that a slave module that has received the DV packet can execute a digital data transmission process that is executed when a null packet or a poll packet is received.   The master module and the slave module are Bluetooth modules, the communication of only the audio signal is communication using an SCO packet, and the digital data transmission process uses a DV packet capable of mixing data and audio. The wireless communication method according to claim 1, wherein communication is performed.   The radio communication method according to claim 1 or 2, wherein the DV packet transmitted from the master module indicates that the packet is a substitute packet of a Null or a Poll packet.   4. The wireless communication method according to claim 2, wherein the communication for transmitting a DV packet at the predetermined period is performed when three SCO links for transmitting the SCO packet are established.

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