JP2010178217A - Communication equipment, communicating method, and control program of communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a connection time until a communication start if communication equipment to be a communication counterpart corresponds to communication equipment while holding compatibility with communication equipment following the existing communication system. <P>SOLUTION: The communication equipment 10 is provided with: a low speed encoder 131 for converting data to be outputted to a secondary station into a communication pattern following a modulation system of a first communication speed; a high speed encoder 132 for converting the data to be outputted to the secondary station into a communication frame following a modulation system of a second communication speed and having a frame length corresponding to the pulse width of one pulse upon receiving one pulse of the communication pattern converted by the low speed encoder 131; and a transmitting part 141 for outputting second communication data converted by the high speed encoder 132 to the secondary station in place of the one pulse of the first communication data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention maintains compatibility with a communication device conforming to an existing communication method, maintains compatibility with a communication device conforming to an existing communication method, and a communication device serving as a communication partner corresponds to the communication device of the present invention. If so, the present invention relates to a communication device, a communication method, and a communication device control program that can shorten the connection time until the start of communication.

  In recent years, communication devices can handle so-called multimedia data such as still images, moving images, and voices, and the data size that communication devices can possess has increased dramatically. In order to share such data between communication devices, a short-range communication method using a wired communication technique, a wireless communication technique, or the like is used.

  As one of the wireless communication technologies, there is a communication system (hereinafter referred to as IrDA (registered trademark) system) defined by an Infrared Data Association, which is disclosed in Non-Patent Documents 1 and 2, for example. Hereinafter, the IrDA method disclosed in Non-Patent Documents 1 and 2 will be described with reference to FIGS.

[IrDA system]
First, a connection procedure when data communication by the IrDA method is performed between communication devices will be described with reference to FIG. FIG. 8 is a diagram illustrating a connection procedure when data communication by the IrDA method is performed between communication devices.

  In the IrDA system, the first communication speed used when a communication device (primary station) recognizes (searches) a communication device (secondary station) as a communication partner and exchanges communication capability is 9600 bps (bit per bit). second). That is, the primary station is a station that first searches for a communication partner (a station that requests establishment of a data transfer state), and a command that requests connection (for example, a station discovery command (XID (Exchange Station Identification) command)) Is the station that sends the message. On the other hand, the secondary station is a station that accepts the request. In FIG. 8, the primary station is the client and the secondary station is the server.

  The primary station outputs the XID command (XIDC0 to XIDC5 in FIG. 8) in order to search for a secondary station to be a communication partner. The XID command is a command for searching for a station that can be a secondary station within a communicable distance from the primary station, and any of 1, 6, 8, and 16 slots can be connected to one or a plurality of communication devices. It is stipulated that the number of slots (number that can search for the partner station at the same time) can be specified. The primary station outputs XID commands for the designated number of slots. The output time of the XID command is about 28 ms, and the output interval of the XID command is about 70 to 80 ms.

  The secondary station that has received the XID returns an XID response (XIDR in FIG. 8), which is a station discovery response, at random between any slot (between XIDC and XIDC or between XIDC and XIDE (described later)), Performs processing to inform the primary station of the existence of its own station. In FIG. 8, the secondary station transmits the XID command (XIDC1) of slot 1 to the primary station after receiving it. Since information such as a nickname is included in the XID response, the output time of the XID response is 28 to 60 ms.

  The primary station outputs XID commands corresponding to the number of slots (six slots in FIG. 8), and then outputs the last XID command XID-END (XIDE in FIG. 8). As a result, the primary station ends the secondary station recognition (search) phase. The output time of XID-END is the same as the XID response and is 28 to 60 ms.

  When the secondary station recognition (search) phase is completed, the primary station exchanges communication capabilities, so parameters necessary for communication such as the maximum transfer speed and maximum receivable data length of the local station (the local station's A parameter indicating communication capability) is notified to the secondary station using a SNRM (Set Normal Response Mode) command. The SNRM command is output so that the transmission is completed within 500 ms after the interval of 10 ms or more from the output of XID-END. The output time of the SNRM command is about 50 ms.

  The secondary station that has received the SNRM command output from the primary station uses the parameters to compare the negotiated value with the set value of its own station or the set value of its own station using the UA (Unnumbered acknowledgment) response. Tell the station. The UA response is output so that the transmission is completed within 500 ms after an interval of 10 ms or more from the input of the SNRM command.

  In this way, the primary station and the secondary station end the communication capability exchange phase for exchanging communication capabilities with each other by inputting and outputting the SNRM command and the UA response.

  When the communication capability exchange phase is completed, the primary station and the secondary station switch the communication speed from the first communication speed (9600 bps) to the second communication speed used when performing upper layer connection processing and data exchange. Thus, the data exchange phase is entered. When shifting to the data exchange phase, the primary station first outputs an RR (Receive Ready) frame for informing that it is ready to receive an I (information) frame. The output timing of the RR frame is not particularly defined, and may be output immediately after receiving the UA response.

  Depending on the secondary station, the RR frame may not be recognized. In this case, the primary station outputs the RR frame again after the elapse of 500 ms or more and within the connection holding time after outputting the first (previous) RR frame. Then, the primary station performs subsequent connection processing at the second communication speed.

  In the IrDA system, 11 types of 2400 bps, 9600 bps, 19.2 kbps, 38.4 kbps, 57.6 kbps, 115.2 kbps, 0.576 Mbps, 1.152 Mbps, 4 Mbps, 16 Mbps, and 100 Mbps are the second in 2008. It is specified as a communication speed, and a higher communication speed will be established in the future.

  As modulation methods, modulation methods with a communication speed of 2400 to 115.2 kbps (commonly known as SIR (Serial IR) method), 0.576 Mbps and 1.152 Mbps modulation methods (bit stuffing NRZ method: commonly known as MIR (Medium IR)). ) Method) 4 Mbps modulation method (4-value PPM method: commonly called FIR (Fast IR) method), 16 Mbps modulation method (HHH method: commonly called VFIR (Very Fast IR) method), and 100 Mbps modulation method (8B10B method) : Nicknamed UFIR system). Hereinafter, the SIR method, which is a modulation method directly related to the present invention, will be described with reference to FIG. 9, and description of other modulation methods will be omitted.

  FIG. 9 is a diagram illustrating how data is converted by the SIR method, which is a modulation method with a communication speed of 2400 to 115.2 kbps.

  As shown in the figure, the communication device adds a start bit (value is 0) and a stop bit (value is 1) to 8-bit data (Data in FIG. 9), thereby providing a UART (Universal Asynchronous Receiver / Transmitter). A frame (UART-Data in FIG. 9) is created. That is, the communication device transmits data as a UART frame when performing communication by the SIR method.

  Thereafter, the communication device generates a pulse when the value of the bit of the UART frame is 0, but does not generate a pulse when the value of the bit is 1, thereby converting the UART frame into the IR frame (FIG. 9). IR-data). In FIG. 9, the generated pulse is indicated by a light-colored rectangle. In addition, since whether or not a pulse is generated for each 8-bit data changes, the IR frame corresponding to the 8-bit data is indicated by a dark rectangle. That is, this dark rectangle means that a light rectangle is shown when a pulse is generated, and nothing is shown when a pulse is not generated.

  Since the first communication speed is 9600 bps, the 1-bit time (time corresponding to 1 bit) of the UART frame is 1/9600 = about 104 μs. In the SIR system, the allowable pulse width output from the communication device is 3/16 + α of the 1-bit time from 1.41 μs, and 1.41 μs to 22.13 μs when the communication speed is 9600 bps. Become.

[Issue with IrDA method]
As described above, in the IrDA system, the communication device switches from the first communication speed to the second communication speed when shifting from the communication capability exchange phase to the data exchange phase. In particular, when the difference between the first communication speed and the second communication speed is several thousand to several tens of thousands of times, the time required for the secondary station recognition (search) phase and communication capacity exchange phase is the data exchange. It takes a lot of time compared to the time required to exchange data in the phase. For this reason, the longer the time required for the secondary station recognition (search) phase and the communication capability exchange phase is, the longer the communication time becomes, resulting in an overhead in communication between communication devices.

  For example, in the case of the IrDA system, when communication is started between communication devices at the first communication speed and then switched to the second communication speed and the time until communication is possible is calculated, the shortest best case is about 740 ms. It takes about 2200 ms in the longest worst case.

  For example, when the second communication speed is 100 Mbps, this time is a time in which data exchange of 74 Mbit (9.25 Mbyte) to 220 Mbit (27.5 MByte) can be performed between the communication devices. Further, for example, when the second communication speed is 500 Mbps, data exchange of 370 Mbit (46.25 MByte) to 1100 Mbit (137.5 MByte) is possible, and when the second communication speed is 1000 Mbps, 740 Mbit (92 .5 Mbyte) to 2200 Mbit (275 MByte) can be exchanged.

  In order to solve the above problem (reduce the overhead), for example, the first communication speed and the second communication speed may be substantially the same, or a difference of several to several tens of times may be considered. . However, in this case, the primary station cannot be compatible with a communication device that can cope with a communication speed having a small difference from the first communication speed. Therefore, an existing communication device according to the current IrDA system is used. It becomes impossible to communicate with. That is, it is difficult to reduce overhead by reducing the difference between the first communication speed and the second communication speed.

  Here, another technique for solving the above problem is disclosed in Patent Documents 2 to 5, for example.

  Patent Document 2 discloses a communication that can multiplex multiplexed data by superimposing a plurality of information on one short pulse by multiplexing the spread data on one pulse and performing pulse compression. A device is disclosed.

  In Patent Document 3, a data area other than FAS (Frame Alignment Signal) and BAS (Bit-rate Allocation Signal) of the H221 frame is used as an area for storing unique control information between communication devices, and is necessary for the connection processing procedure. A communication device for exchanging various information is disclosed. Patent Document 4 discloses a communication device that realizes a unique control procedure by outputting a special frame different from the frame while not outputting a frame defined in a normal method (for example, recommendation H223). Is disclosed. According to these technologies, it is possible to shorten the connection time for exchanging communication capability between communication devices that adopt the same method.

  In Patent Document 5, by comparing the pulse width of the digital signal with the pulse width value for determination and determining the communication speed of the digital signal, the communication speed at the start of communication is analyzed and confirmed at a high speed, and the confirmation time is set. A communication device that can be shortened is disclosed.

  Although not related to the technique for reducing the overhead, for example, Patent Document 1 discloses a technique that realizes a higher communication speed in IrDA communication and enables large-capacity communication. .

  Patent Document 1 discloses that 100 Mbps (high-speed) encoded by a 100 Mbps controller within one bit time after transmitting a 9600 bps (low-speed) information signal pulse (IR-Data in FIG. 9) encoded by an encoder. ) Is provided with a multiplexing circuit for multiplexing the information signal. In this technique, after switching from the communication capability exchange phase to the data exchange phase, communication is performed by superimposing an information signal having a communication speed higher than the communication speed of 9600 bps.

  However, the secondary station according to the current IrDA system does not have a function of separating high-speed optical signals. For this reason, this secondary station uses a DC light (that is, a frequency band that greatly exceeds a frequency band in which a light receiving element (photodiode (PD), phototransistor (PT), etc.) of the secondary station can receive a high-speed optical signal (that is, One pulse). That is, in Patent Document 1, the secondary station receives an unintelligible pulse as a high-speed optical signal after the original pulse (pulse at a communication speed of 9600 bps) cannot be recognized. Will be.

  As a result, in the technique of Patent Document 1, the primary station cannot communicate with a secondary station that does not support the technique, and cannot be compatible with a secondary station that complies with the current IrDA system. Problem arises. Due to this problem, the technique disclosed in Patent Document 1 enables communication between communication devices having a communication function at a high communication speed. For this reason, in Patent Document 1, it is not necessary to superimpose a high-speed communication speed information signal on a low-speed communication speed information signal for compatibility with a secondary station that does not have the technique of Patent Document 1.

JP 2007-129637 A (published May 24, 2007) JP 2004-343388 A (released on December 2, 2004) JP 2000-13465 A (published January 14, 2000) JP 2000-174842 (June 23, 2000) JP 2006-303731 A (released on November 2, 2006)

Infrared Data Association Serial Infrared Link Access Protocol (IrLAP) Version 1.1 (June 16, 1996) Infrared Data Association Serial Infrared Physical Layer Specification Version 1.4 (May 30, 2003)

  However, with the technology of Patent Document 2, communication cannot be performed unless communication devices have the same communication processing capability. For this reason, in the technology of Patent Document 2, when communication devices exchange data, it is necessary to separately perform processing such as exchanging communication capabilities of each other's communication devices, and this processing time is required before starting communication. Problem arises.

  In the technique disclosed in Patent Document 2, the communication device needs to detect a received signal as a wave. However, in the current technology, there is no communication device that can detect an ultrahigh frequency signal such as light as a wave. For this reason, although the technique of patent document 2 can be applied when a radio wave of several GHz to several tens of GHz is received, there arises a problem that it cannot be applied to a communication method using light that is an ultrahigh frequency signal.

  Furthermore, in the technique of Patent Document 3, it is necessary to store control information that can be discriminated between communication devices in a data area that is not used in the H221 frame. For this reason, when there is no unused data area in the frame used by the communication device, there is a problem that the technology of Patent Document 3 cannot be applied to the communication device, and the connection time may not be shortened. .

  The technique of Patent Document 4 is a communication method that cannot be applied to a network having a period during which a special frame is not output from any communication device. For this reason, in the technique of patent document 4, the problem that there exists a possibility that connection time cannot be shortened will arise.

  Furthermore, the technique of Patent Document 5 has a problem in that compatibility with existing communication devices according to the current IrDA method cannot be achieved.

  The present invention has been made in view of the above-described problems, and the object thereof is to maintain compatibility with a communication device according to an existing communication method, and a communication device serving as a communication partner is a communication device of the present invention. If it is compatible, it is possible to provide a communication device, a communication method, and a communication device control program capable of reducing the connection time until communication is started (reducing overhead).

  In order to solve the above problems, a communication device as a primary station according to the present invention searches and recognizes a secondary station to be a communication partner and communicates with the secondary station according to a modulation scheme of the first communication speed. Is a communication device as a primary station that performs upper-layer connection and data exchange with a secondary station in accordance with a second communication speed higher than the first communication speed, and outputs data to the secondary station. Is converted into first communication data in accordance with the first communication speed modulation method, and one pulse of the first communication data converted by the first data conversion unit is received. A second data conversion unit for converting data to be output to the secondary station into second communication data according to the second communication speed modulation method having a data length corresponding to the pulse width of the one pulse; Changed by the second data converter The second communication data, is characterized by comprising an output unit for outputting to the secondary station as an alternative to the one pulse of the first communication data.

  Further, in order to solve the above problems, the communication method as a primary station according to the present invention searches and recognizes a secondary station to be a communication partner according to a modulation scheme of the first communication speed, and communicates with the secondary station. A communication method of a communication device as a primary station for performing communication capacity exchange and performing upper layer connection and data exchange with a secondary station according to a second communication speed higher than the first communication speed, A first data conversion step for converting data to be output to the station into first communication data in accordance with the modulation method of the first communication speed, and one pulse of the first communication data converted by the first data conversion step The second data for converting the data to be output to the secondary station to the second communication data according to the modulation method of the second communication speed having the data length corresponding to the pulse width of the one pulse Conversion step , The second data conversion the second communication data converted by the step, is characterized in that it comprises an output step of outputting to the secondary station as an alternative one pulse of the first communication data.

  According to the above configuration, the communication device (communication method) as the primary station replaces the first communication data according to the modulation method of the first communication speed converted by the first data conversion unit (first data conversion step). The second communication data according to the second communication speed modulation method having a data length corresponding to the pulse width of one pulse of the first communication data, converted by the second data conversion unit (second data conversion step). Is output.

  Therefore, the communication device according to the present invention recognizes (searches for) the secondary station according to the modulation method of the first communication speed, for example, if the communication device as the secondary station is a communication device that can receive the second communication data. ), It is possible to perform connection processing according to the second communication speed modulation method.

  On the other hand, when the communication device as the secondary station is a communication device that can receive only the first communication data (communication device according to the existing communication method), the second communication data includes the second communication speed, the first communication speed, If the speed difference is 100 times or more, it greatly exceeds the receivable frequency of the communication device. For this reason, the communication apparatus according to the existing communication system recognizes the second communication data as one pulse of the first communication data.

  That is, the communication device according to the existing communication method cannot recognize the second communication data output from the communication device according to the present invention, but can recognize it as one pulse of the first communication data. It is possible to perform processing in accordance with the communication speed modulation method. For this reason, the communication device according to the present invention can communicate with the communication device in accordance with the existing communication method even when the second communication data is output instead of the first communication data.

  Therefore, the communication device according to the present invention maintains compatibility with the communication device according to the existing communication method, and if the secondary station is a communication device corresponding to the communication device according to the present invention, the communication device is started. Connection time can be shortened.

  Further, the communication device as the primary station according to the present invention, the reception state of the own device, the first reception state capable of receiving the first communication data according to the modulation method of the first communication speed from the secondary station, Receiving state switching means for switching to a second receiving state capable of receiving second communication data in accordance with a second communication speed modulation method from the secondary station, wherein the receiving state switching means Until the time corresponding to one bit of the first communication data elapses after the output of the communication data instead of one pulse of the first communication data is started, or after the first communication data It is preferable to maintain the second reception state until pulse output is started.

  The reception state switching means is configured to start the output of the second communication data as a substitute for one pulse of the first communication data until a time corresponding to one bit of the first communication data elapses, or Until the output of the next pulse of one communication data is started, the reception state of the own device is maintained in the second reception state.

  Therefore, if the communication device as the secondary station is a device that corresponds to the communication device according to the present invention, the communication device according to the present invention can receive a response to the second communication data from the corresponding device. Become.

  Furthermore, a communication device as a primary station according to the present invention includes first communication control means for controlling connection processing with the secondary station, wherein the first communication control means is configured such that the reception state switching means is the second communication station. When a response to the second communication data is received from the secondary station while in the reception state, it is preferable to perform connection processing according to the modulation method of the second communication speed.

  According to the above configuration, when the first communication control unit receives a response to the second communication data while the reception state switching unit is in the second reception state, the communication device serving as the secondary station becomes the main communication device. It is determined that the device is compatible with the communication device according to the invention, and connection processing according to the modulation method of the second communication speed can be performed.

  Therefore, the communication device according to the present invention can connect the response to the second communication data with the communication device that is the secondary station within a time corresponding to one bit of the first communication data in the shortest time.

  Furthermore, in the communication device as the primary station according to the present invention, the reception state switching unit outputs one pulse of the first communication data after the final pulse of the first communication data including the second communication data is output. It is preferable to switch to the first reception state when a time corresponding to the pulse width of elapses.

  According to the above configuration, even if the communication device according to the present invention is a secondary station (existing communication device) that does not support the communication device, a response to the first communication data is received from the existing communication device. Can be received. Therefore, the communication device according to the present invention can communicate with an existing communication device with compatibility.

  In order to solve the above problems, the communication device as a secondary station according to the present invention searches and recognizes its own device by the primary station and exchanges the communication capability with the primary station according to the modulation method of the first communication speed. And a communication device as a secondary station that performs upper layer connection and data exchange with the primary station according to a second communication speed higher than the first communication speed, according to the modulation method of the first communication speed. When the first communication data is received, connection processing with the primary station is performed according to the modulation method of the first communication speed, and the second communication having a data length corresponding to the pulse width of one pulse of the first communication data. When data is received, second communication control means for performing connection processing with the primary station according to the modulation scheme of the second communication speed is provided.

  Further, in order to solve the above-described problem, the communication method of the communication device as the secondary station according to the present invention searches and recognizes the own device by the primary station according to the modulation method of the first communication speed, and the primary station A communication device as a secondary station that performs data exchange with a higher-layer connection and a primary station according to a second communication speed higher than the first communication speed. When receiving the first communication data according to the modulation scheme of one communication speed, the connection processing with the primary station is performed according to the modulation scheme of the first communication speed, and the pulse width of one pulse of the first communication data is set. When the second communication data having the corresponding data length is received, the connection process with the primary station is performed according to the modulation scheme of the second communication speed.

  According to the above configuration, the communication device (communication method) according to the present invention has the first communication data from the communication device according to the existing communication method and the data length corresponding to the pulse width of one pulse of the first communication data. The second communication data from the communication device that can output the second communication data (communication device as the primary station according to the present invention) can be simultaneously awaited.

  Therefore, the communication device (communication method) according to the present invention can receive the second communication data from the communication device as the primary station according to the present invention and perform the connection process. It is also possible to perform connection processing by receiving first communication data from. That is, the communication device according to the present invention maintains compatibility with the communication device according to the existing communication method, and if the primary station is a communication device as the primary station according to the present invention, the connection time until the start of communication is reduced. It can be shortened.

  Furthermore, it is preferable that the communication device as the primary station according to the present invention communicates with the secondary station existing at a short distance by infrared rays.

  According to the said structure, when communicating with the secondary station which exists in a short distance by infrared rays, there can exist an effect similar to the communication apparatus (communication method) as said primary station.

  Furthermore, it is preferable that the communication device as the secondary station according to the present invention communicates with the primary station existing at a short distance by infrared rays.

  According to the said structure, when performing communication with the primary station which exists in a short distance by infrared rays, there can exist an effect similar to the communication apparatus (communication method) as said secondary station.

  Note that the communication device as the primary station and the communication device as the secondary station may be realized by a computer. In this case, the computer is caused to execute processing of the communication device. Thus, a control program for realizing the communication device as the primary station and the communication device as the secondary station by a computer also falls within the scope of the present invention.

  As described above, the communication device as the primary station according to the present invention, the first data conversion unit that converts the data output to the secondary station into the first communication data according to the modulation scheme of the first communication speed And when one pulse of the first communication data converted by the first data converter is received, the data to be output to the secondary station is the data length corresponding to the pulse width of the one pulse. A second data conversion unit that converts the second communication data in accordance with a modulation method of the second communication speed; and the second communication data converted by the second data conversion unit is converted into one pulse of the first communication data. Instead, the output unit outputs to the secondary station.

  The communication method of the communication device as the primary station according to the present invention includes a first data conversion step of converting data output to the secondary station into first communication data according to the modulation method of the first communication speed. And when one pulse of the first communication data converted by the first data conversion step is received, the data to be output to the secondary station is the data length corresponding to the pulse width of the one pulse. A second data conversion step for converting to second communication data in accordance with a modulation method of the second communication speed; and the second communication data converted by the second data conversion step is converted into one pulse of the first communication data. An output step of outputting to the secondary station instead.

  Further, when the communication device as the secondary station according to the present invention receives the first communication data according to the modulation method of the first communication speed, the communication device is connected to the primary station according to the modulation method of the first communication speed. When the second communication data having a data length corresponding to the pulse width of one pulse of the first communication data is received, a connection process with the primary station is performed according to the second communication speed modulation method. It is the structure provided with the communication control means.

  Further, the communication method of the communication device as the secondary station according to the present invention, when receiving the first communication data according to the modulation method of the first communication speed, the primary station according to the modulation method of the first communication speed. When the second communication data having a data length corresponding to the pulse width of one pulse of the first communication data is received, the connection process with the primary station is performed according to the second communication speed modulation method. How to do it.

  Therefore, the communication device and the communication method according to the present invention maintain compatibility with the communication device according to the existing communication method, and if the communication device serving as the communication partner is compatible with the communication device of the present invention, There is an effect that the connection time until the start can be shortened.

It is a block diagram which shows the principal part structure of the communication apparatus as a primary station which concerns on this embodiment. It is a block diagram which shows an example of schematic structure of the communication apparatus which concerns on this embodiment. It is a figure for demonstrating the data processing of the communication controller in the communication apparatus shown in FIG. It is a figure for demonstrating the switching timing of the reception state in the communication apparatus shown in FIG. It is a figure which shows the frame format at the time of the connection start in IrDA system (at the time of SIR communication; communication at the time of the modulation system whose 1st communication speed is 9600 bps). It is a block diagram which shows the principal part structure of the communication apparatus as a secondary station which concerns on this embodiment. It is a figure for demonstrating the input / output signal of the physical layer device in the communication apparatus shown in FIG. It is a figure which shows a prior art and shows the connection procedure when the data communication by an IrDA system is performed between communication apparatuses. It is a figure which shows a prior art and shows a mode that data are converted by the SIR system which is a modulation system with a communication speed of 2400-115.2 kbps.

  The embodiment of the present invention will be described with reference to FIGS. 1 to 7 as follows.

[Outline of communication equipment]
First, the configuration of the communication device 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 2 is a block diagram illustrating an example of a schematic configuration of the communication device according to the present embodiment.

  The communication device 1 conforms to, for example, the IrDA system, and outputs data to the outside by wireless communication using infrared rays. The communication device 1 can transmit and receive multimedia data such as still images, moving images, and voices, and notebook PCs. (Personal Computer), a display device, a printing device, a recording device, and the like. The communication device 1 includes a control unit 11, a memory 12, a communication controller 13, a physical layer device 14, and a bus 15.

  In this embodiment, a case where the communication method conforms to the IrDA method of short-distance wireless communication will be described as an example. Good.

  The control unit 11 performs control of the communication device 1 and program processing such as an application. For example, the control unit 11 reads and writes data from the memory 12 and controls the communication controller 13 and the physical layer device 14. The configuration of the control unit 11 will be described later.

  The memory 12 stores various information such as a program necessary for the control unit 11 to perform processing and data necessary for communication with the secondary station. The memory 12 may be realized by a rewritable nonvolatile memory such as an EEPROM (electrically erasable programmable read only memory) or a flash memory, or may be realized by a RAM (random access memory) which is a volatile memory. Good.

  The communication controller 13 performs packetization (framing) and encoding of data, which is a process necessary when data is output, for example, in accordance with instructions from the control unit 11. Further, the communication controller 13 performs processing for extracting data from an externally received signal (that is, a packetized and encoded signal) in accordance with an instruction from the control unit 11. The configuration of the communication controller 13 will be described later.

  The physical layer device 14 modulates the data packetized and encoded by the communication controller 13 into a signal that can actually communicate with the secondary station, such as light, voltage, and RF (Radio frequency) signal. , Output to the outside. The physical layer device 14 receives data from the outside and demodulates the data into a signal that can be received by the communication controller 13.

  For this reason, as shown in FIG. 1, the physical layer device 14 includes a transmission unit 141 (output unit) and a reception unit 142 for performing communication with the outside. The transmission unit 141 is, for example, a light emitting module (light emitting element) for performing infrared communication, and includes an LED (Light emitting diode) for transmitting data, an LD (Laser Diode), and the like. On the other hand, the receiving unit 142 is, for example, a light receiving module (light receiving element) for performing infrared communication, and includes a data receiving PD, PT, and the like.

  The bus 15 is a path for exchanging data between the control unit 11, the memory 12, and the communication controller 13, and is an address line used for designating a data transfer location and data used for data transfer. Lines, including control lines used to measure transfer timing.

  In the following description, the communication device 1 as the primary station will be described as the communication device 10, and the communication device 1 as the secondary station will be described as the communication device 20.

[Control by communication equipment as primary station]
Next, the communication device 10 as a primary station according to the present embodiment will be described with reference to FIGS. 1 and 3. FIG. 1 is a block diagram showing a main configuration of a communication device as a primary station. Since the memory 12, the physical layer device 14, and the bus 15 have been described above, description thereof will be omitted.

  As illustrated in FIG. 1, the communication controller 13 of the communication device 10 includes a low-speed encoder 131 (first data conversion unit), a high-speed encoder 132 (second data conversion unit), a multiplexer 133, and a decoder 134.

  The low-speed encoder 131 converts data to be output to the secondary station in accordance with a first communication speed modulation method capable of performing low-speed communication, that is, converts the data into a frame and generates a pulse. In the present embodiment, the low-speed encoder 131 converts data in accordance with, for example, an SIR method with a first communication speed of 9600 bps.

  Note that the low-speed encoder 131 may be configured to only generate pulses. In this case, the low-speed encoder 131 has a configuration having only a pulse conversion function of data framed using the control unit 11 (that is, by software).

  The high-speed encoder 132 converts (frames) data to be output to the secondary station in accordance with a second communication speed modulation method capable of performing high-speed communication. In the present embodiment, the high-speed encoder 132 converts data in accordance with, for example, the UFIR method with a second communication speed of 100 Mbps or a higher-speed method scheduled to be established in the future.

  When the high-speed encoder 132 receives one pulse of data (first communication speed communication pattern; first communication data) according to the first communication speed modulation method converted by the low-speed encoder 131, A function of converting data to be output to the station into data (second communication speed communication frame; second communication data) according to the second communication speed modulation method having a frame length corresponding to the pulse width of the one pulse. It is what you have.

  The multiplexer 133 (output unit) outputs either the data converted by the low-speed encoder 131 or the data converted by the high-speed encoder 132 to the physical layer device 14 at the subsequent stage. Based on a selection signal (first selection signal, second selection signal) output from the unit 111, output switching of the two data is performed.

  That is, the multiplexer 133 outputs the communication frame of the second communication speed converted by the high speed encoder 132 during the connection operation to the physical layer device 14 instead of one pulse of the communication pattern of the first communication speed. Then, the physical layer device 14 outputs the received communication frame at the second communication speed to the secondary station.

  The decoder 134 decodes the data encoded by the secondary station received by the physical layer device 14 based on the reception state signal output from the reception state switching unit 112 described later, and the secondary station encodes it. This is to restore the original data before conversion.

  As shown in FIG. 1, the control unit 11 includes a selection control unit 111, a reception state switching unit 112 (reception state switching unit), a reception state monitoring unit 113, and a communication control unit 114 (first communication control unit). ing. Each functional block provided in the control unit 11 can be realized by, for example, a CPU (Control Processing Unit) serving as the control unit 11 reading and executing a program stored in the ROM or the like to the RAM or the like.

  The selection control unit 111 controls the multiplexer 133 to output the data from the low speed encoder 131 or the data from the high speed encoder 132 to the physical layer device 14. Therefore, the selection control unit 111 outputs a first selection signal for causing the physical layer device 14 to output data from the low speed encoder 131 or a second for causing the physical layer device 14 to output data from the high speed encoder 132. The selection signal is transmitted to the multiplexer 133.

  The reception state switching unit 112 switches the reception state of the communication device 10 (particularly, the communication controller 13 and the physical layer device 14) according to the timing at which data is output from the physical layer device 14. Here, the reception state includes a first reception state in which a communication pattern at a first communication speed can be received, or a second reception state in which a communication frame at a second communication speed can be received.

  That is, the reception state switching unit 112 transmits the second reception state signal to the physical layer device 14 and the decoder 134 as a reception state signal in the state of receiving the communication frame at the second communication speed. The second reception state signal is a signal for performing reception processing and conversion processing of a communication frame at the second communication speed. As a result, the physical layer device 14 and the decoder 134 enter a second reception state in which data according to the modulation scheme of the second communication speed can be received.

  On the other hand, in the state of receiving the communication pattern of the first communication speed, the reception state switching unit 112 transmits the first reception state signal to the communication controller 13 and the physical layer device 14 as a reception state signal. The first reception state signal is a signal for performing reception processing and conversion processing of the communication pattern at the first communication speed. As a result, the communication controller 13 and the physical layer device 14 enter a first reception state in which data according to the modulation method of the first communication speed can be received.

  The reception state monitoring unit 113 monitors whether or not the reception unit 142 has received a response corresponding to the communication pattern of the first communication speed or the communication frame of the second communication speed during the first or second reception state. Is.

  The communication control unit 114 performs station discovery processing (processing in the secondary station recognition (search) phase), communication capability exchange processing (processing in the communication capability exchange phase), and higher layer connection processing and data exchange processing ( It controls connection processing for communication with the secondary station, such as control of data exchange phase) and communication speed.

  That is, the communication control unit 114 searches and recognizes a secondary station that is a communication partner and exchanges communication capability with the secondary station according to the modulation method of the first communication speed, and is higher than the first communication speed. According to the second communication speed, each unit of the communication device 10 is controlled so as to connect the upper layer and exchange data with the secondary station. Note that the communication capability is a capability possessed by the own device such as a communication speed in data communication with a secondary station, a time interval between communication patterns (communication frames), a timeout at the time of communication interruption, for example, SNRM. Refers to the parameter included in the command.

  In particular, when the communication control unit 114 receives a response to the communication frame at the second communication speed from the secondary station while the reception state switching unit 112 is in the second reception state, the communication control unit 114 modulates the second communication speed. Perform connection processing according to the method.

  Next, data processing of the communication controller 13 will be described with reference to FIG. FIG. 3 is a diagram for explaining data processing of the communication controller 13.

  First, the communication control unit 114 controls the communication controller 13 and the physical layer device 14 in order to output a station discovery command to the outside in order to recognize (search) a communication partner. Specifically, for example, when receiving a data transmission instruction from the user via an operation unit (not shown), the communication control unit 114 generates a station discovery command and transmits it to the low-speed encoder 131 of the communication controller 13.

  At this time, the selection control unit 111 transmits the second selection signal to the multiplexer 133. That is, while receiving the second selection signal, the multiplexer 133 can output only the data from the high-speed encoder 132 to the physical layer device 14.

  When the low-speed encoder 131 receives the station discovery command, the low-speed encoder 131 converts the station discovery command into a frame according to the SIR method that is the modulation method of the first communication speed, and converts it into an SIR communication pattern (a communication pattern of the first modulation method).

  That is, as shown in FIG. 3, the low-speed encoder 131 adds a start bit (value is 0) and a stop bit (value is 1) to the station discovery command (Data in FIG. 3) to add a UART frame ( UART-Data in FIG. 3 is created. FIG. 3 shows one byte of the station discovery command input to the low-speed encoder 131.

  Next, the low-speed encoder 131 generates a pulse when the bit value of the UART frame is 0, but does not generate a pulse when the bit value is 1, so that the UART frame is transmitted to the first communication speed. The communication pattern (modulated signal of the first communication speed) ((a) of FIG. 3) is converted.

  That is, the low-speed encoder 131 always generates a pulse because the value of the start bit is 0 in the first 1-bit time, and generates a pulse according to the data in the 8-bit time of the next data portion, and the last 1-bit. In time, since the value of the stop bit is 1, no pulse is generated.

  When the low-speed encoder 131 generates a communication pattern of the first communication speed, the low-speed encoder 131 sequentially outputs the generated communication pattern pulses to the high-speed encoder 132 and the multiplexer 133. Note that the low-speed encoder 131 may output the enable signal for a time corresponding to the pulse width instead of outputting the generated pulse to the high-speed encoder 132.

  When detecting the rising edge of the pulse from the low-speed encoder 131, the high-speed encoder 132 notifies the communication control unit 114 of the detection. Upon receiving this notification, the communication control unit 114 reads data (for example, data corresponding to the station discovery command and SNRM command) according to the modulation method of the second communication speed from the memory 12 and transmits the data to the high-speed encoder 132.

  When the high-speed encoder 132 receives the data read by the communication control unit 114, the high-speed encoder 132 frames the data according to the modulation method of the second communication speed. Specifically, as shown in FIG. 3B, the high-speed encoder 132 adds a preamble (“PA”), a start flag (“STA”), a cyclic code (“Data”) to the received data body (“Data”). "CRC") and a stop flag ("STO").

  The high-speed encoder 132 converts the data into a communication frame at the second communication speed, and then outputs the communication frame to the multiplexer 133 within a time corresponding to the pulse width permitted by the modulation method at the first communication speed. In the present embodiment, since the first communication speed is 9600 bps, the high-speed encoder 132 needs to transmit a communication frame at the second communication speed between 1.41 μs and 22.13 μs.

  The reason why the high speed encoder 132 can transmit the communication frame at the second communication speed within the time corresponding to the pulse width is that the speed difference between the first communication speed and the second communication speed is sufficiently large. The reason for this will be described below.

  Since the multiplexer 133 receives the second selection signal, the multiplexer 133 transmits only the communication frame from the high-speed encoder 132 to the physical layer device 14. That is, the multiplexer 133 ignores the pulse of the communication pattern of the first communication speed generated by the low speed encoder 131. Then, the physical layer device 14 modulates the communication frame of the second communication speed from the high-speed encoder 132 selected by the multiplexer 133 into light, voltage, RF signal, etc., and outputs it to the outside.

  As described above, when the communication device 10 recognizes (searches) the secondary station, the communication device 10 uses the second communication pattern generated by the high-speed encoder 132 instead of the communication pattern of the first communication speed generated by the low-speed encoder 131. It is the structure which outputs the communication frame of communication speed. For this reason, when the communication device 10 is a communication device that can receive a communication frame of the second communication speed (opposite device) as a secondary station, It is possible to perform connection processing according to the second communication speed modulation method.

  On the other hand, when the communication device that is the secondary station is a communication device that can receive only the communication pattern of the first communication speed (existing communication device according to the current IrDA system), the communication frame of the second communication speed is the second If the speed difference between the communication speed and the first communication speed is 100 times or more, the receivable frequency of the communication device is greatly exceeded. For this reason, this existing communication apparatus recognizes the communication frame of the second communication speed as one DC pulse, that is, one pulse of the communication pattern of the first communication speed.

  That is, the existing communication device cannot recognize the communication pattern of the second communication speed output from the communication device 10, but can recognize it as one pulse of the communication pattern of the first communication speed. It is possible to perform processing according to the modulation method. Therefore, the communication device 10 can communicate with the existing communication device even when the communication frame of the second communication speed is output instead of the communication pattern of the first communication speed.

  Accordingly, the communication device 10 maintains compatibility with the communication device according to the existing communication method, and shortens the connection time until the communication starts if the secondary station is a communication device compatible with the communication device 10. be able to.

  Here, the frame structure of the communication frame of the second communication speed shown in FIG. As described above, the communication frame at the second communication speed includes “PA”, “STA”, “Data”, “CRC”, and “STO”.

  “PA” is a field for stabilizing the physical layer device 14 of a communication device that is a communication partner, whereby the communication device can stably receive data. Further, “PA” is a field necessary for a CDR (Clock & Data Recovery) circuit (not shown) included in a communication device to be a communication partner to generate a clock and reproduce data. Normally, in wireless communication, a communication device as a primary station modulates data so that a clock component can be easily detected and outputs the data on a transmission line. Therefore, when a communication partner of the communication device receives data by the CDR circuit, it is necessary to generate a clock serving as a base of the data and reproduce the data.

  “STA” is a field for indicating the start of data in a frame. Note that “STA” normally stores a special value that does not occur even when data is circulated.

  “Data” is a field for storing a data body (IrLAP layer payload data).

  “CRC” is a field for error detection (to confirm data integrity).

  “STO” stores a special value that does not occur even if it circulates when data indicating that “Data” and “CRC” have ended is modulated.

  Here, “it does not occur even if it circulates” means that there is no corresponding pattern even when all combinations of codes in the modulated data are shifted one bit at a time. For example, in the case of the 4-level PPM method, one frame has four codes “0001”, “0010”, “0100”, and “1000”. In this case, a pattern such as “11000110” does not occur. This is because “11” is a combination of “0001” and “1000”, and there is no pattern connected to “11” immediately after “11000”. That is, in the quaternary PPM method, a value that does not occur even if it circulates indicates a pattern such as “11000110”.

  Storing “special value that does not occur even if it circulates” in “STA” and “STO” is because the communication device does not synchronize the bits (it does not know which bit is the first bit of the modulated data). This is to prevent an error that recognizes the modulated data as “STA” or “STO” even if the data is received occasionally.

  The high-speed encoder 132 performs framing and compression processing on the received data at the timing when the rising edge of the pulse output from the low-speed encoder 131 is detected, but is not limited to this. That is, the high speed encoder 132 may perform processing at a preset timing or may perform processing at a timing instructed by the control unit 11.

  When the communication capability exchange phase is started after recognizing the secondary station, for example, the selection control unit 111 transmits the first selection signal to the multiplexer 133, so that the multiplexer 133 is converted by the low-speed encoder 131. The communication pattern of the first communication speed is output.

  When the communication capability exchange phase shifts to the data exchange phase, the selection control unit 111 transmits the second selection signal to the multiplexer 133, so that the multiplexer 133 converts the second communication speed converted by the high-speed encoder 132. The communication frame is output. At this time, it is preferable that the high speed encoder 132 frames the data received from the communication control unit 114 without waiting for the pulse of the communication pattern of the first communication speed output from the low speed encoder 131.

  Furthermore, the communication device 10 according to the present embodiment includes two encoders, a low-speed encoder 131 and a high-speed encoder 132, but is not limited thereto, and includes a plurality of encoders corresponding to a plurality of modulation schemes. A configuration in which outputs from a plurality of encoders are switched may be employed. In this case, it is preferable that the selection control unit 111 performs control so that the output of the encoder is appropriately switched after the communication capability exchange phase ends.

  Further, the high-speed encoder 132 may be configured to output a communication frame at the second communication speed instead of at least one pulse of the communication pattern at the first communication speed converted by the low-speed encoder 131. In this case, for example, the selection control unit 111 transmits a pulse corresponding to the start bit of the communication frame at the first communication speed, and then transmits a first selection signal to the multiplexer 133. The multiplexer 133 outputs the pulse from the low-speed encoder 131 (the remaining pulse of the communication pattern of the first communication speed (8-bit data stored next to the start bit)) to the physical layer device 14.

[Reception state switching at the primary station]
Next, the reception state switching timing in the communication device 10 will be described with reference to FIG. FIG. 4 is a diagram for explaining the switching timing of the reception state in the communication device 10.

  First, as described above, the communication device 10 outputs a communication frame of the second communication speed from the physical layer device 14 instead of the communication pattern of the first communication speed. The time for which the communication frame at the second communication speed is output from the physical layer device 14 corresponds to T1 in FIG.

  When the output of the communication frame (one pulse of the communication pattern of the first communication speed) is completed, the physical layer device 14 transmits an output completion signal indicating that the output is completed to the reception state switching unit 112.

  When receiving the output completion signal, the reception state switching unit 112 transmits a second reception state signal to the communication controller 13 and the physical layer device 14. As a result, the communication controller 13 and the physical layer device 14 enter the second reception state.

  When the reception state monitoring unit 113 confirms that the reception state switching unit 112 has entered the second reception state, the response corresponding to the communication frame of the second communication speed output from the transmission unit 141 (second communication speed data). Is monitored by the reception unit 142 during the second reception state. When the reception state monitoring unit 113 determines that the data of the second communication speed is received by the reception unit 142 during the second reception state, the communication control unit 114 performs communication according to the modulation method of the second communication speed. After processing in the capability exchange phase, the process proceeds to the data exchange phase, and connection processing such as data exchange according to the modulation method of the second communication speed is performed. Note that the communication control unit 114 may switch to a modulation method with a communication speed different from the second communication speed during the communication capability exchange phase.

The second reception state is shown in FIG.
T1 = communication frame output time of second communication speed T2 = 1 bit time of pulse of communication pattern of first communication speed−T1
Then, the time T2 after the communication frame of the second communication speed is output, or the next pulse of the communication pattern of the first communication speed after the communication frame of the second communication speed is output (the next second communication (Speed communication frame) until the start of output (T2 + 1 bit time of pulse of communication pattern of the first communication speed × n: n is an integer). The reception state monitoring unit 113 recognizes the start of output of a communication frame at the next second communication speed by receiving, for example, a notification (output start signal) from the physical layer device 14.

  In other words, the reception state switching unit 112 outputs the communication frame at the second communication speed instead of one pulse of the communication pattern at the first communication speed until the time corresponding to T2 elapses (that is, the second communication speed). Until the time corresponding to one bit of the communication pattern of the first communication speed elapses after the output of the communication frame of the speed as a substitute for one pulse of the communication pattern of the first communication speed starts. Maintain communication state. Alternatively, the reception state switching unit 112 starts the output of the communication frame at the second communication speed instead of one pulse of the communication pattern at the first communication speed, and then continues to the communication pattern next to the communication pattern at the first communication speed. The second reception state is maintained until a pulse is output.

  On the other hand, when the reception state monitoring unit 113 determines that the data of the second communication speed has not been received by the reception unit 142 during the second reception state, the reception state switching unit 112 cancels the second reception state. . Thereafter, when the output of the communication frame of the next second communication speed is completed from the physical layer device 14 and the output completion signal is received from the physical layer device 14, the reception state switching unit 112 switches the communication controller 13 and the physical layer device 14 to each other. Return to the second reception state.

  The reception state switching unit 112 determines whether the communication frame of the second communication speed output from the physical layer device 14 corresponds to the last pulse (final pulse) in the communication pattern of the first communication speed. It is confirmed whether or not. For example, the reception state switching unit 112 sends a notification indicating that a communication frame having a second communication speed corresponding to a pulse corresponding to the last bit among bits having a UART frame value of 0 is transmitted to the multiplexer 133. The confirmation is performed by receiving from the communication controller 13.

  When the reception state switching unit 112 confirms that the communication frame has the second communication speed corresponding to the last pulse and then receives an output completion signal indicating completion of output of the communication frame, the communication controller 13 and the physical layer device 14 is set to the second reception state. When the reception state monitoring unit 113 determines that the data of the second communication speed has not been received by the reception unit 142 during the second reception state, the reception state switching unit 112 communicates the first reception state signal. Transmit to the controller 13 and the physical layer device 14. That is, the reception state switching unit 112 outputs the pulse width of one pulse of the communication pattern of the first communication speed after the last pulse of the communication pattern of the first communication speed including the communication frame of the second communication speed is output. When the corresponding time has elapsed, the mode is switched to the first reception state.

  As a result, the communication controller 13 and the physical layer device 14 are switched from the second reception state to the first reception state. The communication controller 13 and the physical layer device 14 are maintained in the first reception state until the next data (for example, the next station discovery command) is output (T3 in FIG. 4).

  When the reception state monitoring unit 113 confirms that the reception state switching unit 112 has entered the first reception state, the response corresponding to the communication pattern of the first communication speed output by the transmission unit 141 (first communication speed data). Is monitored by the reception unit 142 during the first reception state.

  In the case of a secondary station that performs connection processing according to the modulation method of the first communication speed, even if the secondary station receives the communication frame of the second communication speed output from the transmission unit 141, the secondary station Recognized as one pulse of a communication pattern of one communication speed. For this reason, when the communication device 10 outputs all the pulses for the data according to the modulation method of the first communication speed, the secondary station recognizes the communication pattern of the first communication speed and sends a response corresponding to the communication pattern. Transmit to the communication device 10.

  When the reception state monitoring unit 113 determines that the data of the first communication speed is received by the reception unit 142 during the first reception state, the communication control unit 114 performs communication according to the modulation method of the first communication speed. After performing the capability exchange phase, the process proceeds to the data exchange phase according to the second communication speed modulation method. That is, when the communication device 10 receives a response to the communication pattern at the first communication speed from the secondary station, the communication device 10 performs an existing connection process according to the IrDA method.

  As described above, the reception state switching unit 112 outputs the 1-bit time of the communication pattern of the first communication speed after the communication frame of the second communication speed is output or the communication frame of the second communication speed is output. The communication controller 13 and the physical layer device 14 are set to the second reception state for the time until the output of the communication frame at the second communication speed corresponding to the next communication frame pulse at the first communication speed. In addition, when the last pulse of the communication pattern having the first communication speed including the communication frame having the second communication speed is output, the reception state switching unit 112 switches the second reception state to the first reception state.

  Therefore, if the communication device serving as the secondary station is a device compatible with the communication device 10, the communication device 10 can receive a response to the communication frame at the second communication speed from the secondary station.

  When the communication control unit 114 receives the response during the second reception state, the communication control unit 114 determines that the secondary station is a device corresponding to the communication device 10 and follows the modulation method of the second modulation speed. Perform connection processing.

  For this reason, the communication device 10 sends the response of the first communication speed output next after the end of the communication pattern output of the first communication speed at the longest within 1 bit time of the communication pattern of the first communication speed at the shortest. Connection to a communication device as a secondary station can be made within the first bit time of the communication pattern.

  In this case, the time until the communication device 10 becomes communicable with the secondary station corresponding to the communication device 10 is about 100 μs to 80 ms, which is much larger than that in the case of the current IrDA system (about 740 ms to 2200 ms). Can be shortened.

  On the other hand, even if the communication device 10 is a secondary station (existing communication device) that is not compatible with the communication device 10, the communication device 10 receives a response to the pulse of the communication pattern of the first communication speed from the existing communication device. can do. For this reason, the communication device 10 can communicate with the existing communication device with compatibility.

[Frames with the first communication speed (9600 bps) in IrDA]
Here, the frame format at the start of connection in the IrDA system (at the time of SIR communication; at the time of communication in the modulation system with the first communication speed of 9600 bps) will be described with reference to FIG. FIG. 5 is a diagram showing a frame format at the start of connection in the IrDA system (at the time of SIR communication; at the time of communication in a modulation system with a first communication speed of 9600 bps).

  “Additional BOF (Additional Beginning Of Frame)” is a field added to the head as necessary, and is composed of 10 bytes before connection is made. The stored value is either “0xFF” (value recommended in the current IrDA standard; Non-Patent Document 1) or “0xC0” (value used in the initial IrDA system). It is.

  “BOF (Beginning Of Frame”) is a field composed of 1 byte representing the head of the frame, and the value during SIR communication is “0xC0”.

  “Data” is a field for storing a data body (IrLAP layer payload data).

  “FCS (Frame Check Sequence)” is a field for error detection (to check data integrity), and is a 2-byte CRC (Cyclic Redundancy Check) during SIR communication.

  “EOF (End Of Frame)” is a field indicating the end of the frame, and the value at the time of SIR communication is “0xC1”.

  Since “BOF” uses “0xC0” and “EOF” uses “0xC1” as special codes, “Data” and “FCS” are “0xC0”, “0xC1” and “0x7D”. Each code is converted into a 2-byte code starting with “0x7D”.

  Here, “Additional BOF” is a field for enabling a communication device to maintain a transmission interval between frames without using a timer (not shown). That is, even when the communication device starts transmitting a frame after a meaningful BOF at the start of the first connection immediately after a frame received or transmitted before that frame, it is 10 ms or more from the previous frame. It is a field that exists only for opening and sending.

  In other words, “Additional BOF” does not store a meaningful value such as the stabilization of the physical layer device of the communication partner (in the SIR method, since it is asynchronous like UART, it is in units of 1 byte. (In other words, “Additional BOF” is not a field for stabilization.)

  Therefore, the value stored in “Additional BOF” may be any value other than “0xC0”, “0xC1”, and “0x7D”. For this reason, instead of outputting the communication frame of the second communication speed at the time corresponding to one pulse width of the communication pattern of the first communication speed (T1 in FIG. 4), the communication device 10 uses this “Additional BOF”. It may be configured to output at the output time.

  However, the last “Additional BOF” should have only the start bit in order to synchronize the start bit of “BOF”. Therefore, the communication device 10 may not be configured to output the communication frame at the second communication speed for the last “Additional BOF” at the time when the “Additional BOF” is output.

[Difference in communication speed]
In addition, a speed difference between the first communication speed and the second communication speed used in the communication device 10 will be described.

  The high-speed encoder 132 of the communication device 10 needs to output the communication frame at the second communication speed to the multiplexer 133 with a frame length corresponding to one pulse width of the communication pattern at the first communication speed. Therefore, the speed difference needs to be a large difference to some extent as follows. The reason for this will be specifically described by taking the case of the IrDA system as an example.

  For example, in the communication frame at the second communication speed shown in FIG. 3, the data amount from “STA” to “STO” is 40 bytes. The amount of data stored in “PA” for stabilizing the physical layer device of the secondary station and generating the clock and reproducing the data by the CDR circuit is set as large as possible (for example, 200 bytes). Increasing the amount of data stored in “PA” can increase the lock time of the CDR circuit. By extending the lock time, the allowable value of the CDR circuit is increased, the eye pattern is small, and even if the reception state is poor such that the SN ratio (Signal to Noise ratio) is small, the secondary station performs the second communication. Speed communication frames can be received.

Accordingly, the total frame length of the communication frame at the second communication speed is 240 bytes. In order for the high speed encoder 132 to output a communication frame having this frame length within 22.13 μs which is the upper limit value of the pulse width of the first communication speed, the second communication speed is set to
240 × 8 ÷ 22.13 μs = 86.76 Mbps
It is necessary to do it above. That is, in the case of the IrDA method, in order for the high-speed encoder 132 to transmit a communication frame of the second communication speed instead of one pulse of the communication pattern of the first communication speed, the speed difference needs to be about 9000 times or more. There is.

[Control with communication equipment as secondary station]
Next, the communication device 20 as a secondary station according to the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a block diagram showing a main configuration of a communication device as a secondary station. Since the memory 12 and the bus 15 have been described above, description thereof will be omitted.

  As shown in FIG. 6, the communication controller 13 of the communication device 20 includes a low speed decoder 231, a high speed decoder 232, and an encoder 233.

  The low-speed decoder 231 converts the data output from the primary station in accordance with the modulation method of the first communication speed capable of performing low-speed communication. Specifically, the low-speed decoder 231 decodes data according to the modulation scheme of the first communication speed based on an output signal O1 (described later) from the physical layer device 14, and the original data before the primary station encodes it. Return to.

  The high-speed decoder 232 converts data output from the primary station in accordance with a second communication speed modulation method capable of performing high-speed communication. Specifically, the high-speed decoder 232 decodes data according to the modulation scheme of the second communication speed based on an output signal O2 (described later) from the physical layer device 14, and the original data before being encoded by the primary station Return to.

  The encoder 233 converts a response to the data in accordance with the modulation method of the data received by the physical layer device 14, that is, the response is framed to generate a pulse.

  The physical layer device 14 includes a transmission unit 241, a reception unit 242, and an AC / DC extraction unit 243. Note that the transmission unit 241 has a function similar to that of the transmission unit 141 described above, and a description thereof is omitted here.

  The receiving unit 242 is capable of receiving data according to the second communication speed modulation method when receiving data according to the first communication speed modulation method (for example, when receiving a station discovery command). The receiving unit 242 is, for example, a light receiving module (light receiving element) for performing infrared communication, and includes a data receiving PD, PT, and the like.

  The AC / DC extraction unit 243 extracts a DC (Direct Current) component and an AC (Alternate Current) component from the data received by the reception unit 242. The AC / DC extraction unit 243 outputs the extracted DC component to the low-speed decoder 231 and the extracted AC component to the high-speed decoder 232, respectively.

  Furthermore, the control unit 11 includes a data analysis unit 211 and a communication control unit 212 (second communication control means).

  The data analysis unit 211 analyzes data output from the low speed decoder 231 and the high speed decoder 232.

  The communication control unit 212 performs station discovery processing (processing in the secondary station recognition (search) phase in the primary station), communication capability exchange processing (processing in the communication capability exchange phase), and upper layer connection processing and data. It controls connection processing for communication with the primary station, such as control of exchange processing (processing in the data exchange phase) and control of communication speed.

  That is, the communication control unit 212 searches and recognizes the communication device 20 by the primary station and exchanges the communication capability with the primary station according to the modulation method of the first communication speed, and the second higher than the first communication speed. According to the communication speed, each unit of the communication device 20 is controlled so as to connect the upper layer and exchange data with the primary station. The communication capability is, for example, the capability possessed by the own device such as a communication speed in data communication with the primary station, a time interval between communication patterns (communication frames), a timeout at the time of communication interruption, for example, an SNRM response Refers to the parameters included in.

  In addition, when the communication control unit 212 receives the communication pattern of the first communication speed, the communication control unit 212 performs connection processing with the primary station according to the modulation method of the first communication speed, and one pulse of the communication pattern of the first communication speed. When a communication frame having a frame length corresponding to the pulse width and having a second communication speed is received, it has a function of performing a connection process with the primary station in accordance with the second communication speed modulation method.

  Therefore, the communication control unit 212 causes the encoder 233 and the physical layer device 14 to transmit a response according to the first communication speed or the second communication speed to the primary station based on the analysis result of the data analysis unit 211. Control.

  Next, input / output signals of the physical layer device 14 will be described with reference to FIG. FIG. 7 is a diagram for explaining input / output signals of the physical layer device 14. In FIG. 7, the data received by the receiving unit 242 is input signal I, the signal output from the AC / DC extracting unit 243 to the low-speed decoder 231 is output, and the data output from the AC / DC extracting unit 243 is output to the high-speed decoder 232. This signal is referred to as an output signal O2. FIG. 7A shows input / output signals in the AC / DC extraction unit 243 when data (pulses) in accordance with the modulation scheme of the first communication speed is received, and FIG. ) Shows input / output signals in the AC / DC extraction unit 243 when data according to the modulation method of the second communication speed is received.

  The receiving unit 242 outputs the input signal I from the primary station to the AC / DC extracting unit 243. As shown in FIG. 7A, the AC / DC extraction unit 243 detects a variation in the DC component when the input signal I is data in accordance with the modulation scheme of the first communication speed, A pulse having the same pulse width is output as the output signal O1. In addition, the AC / DC extraction unit 243 outputs, as an output signal O2, a pulse in a frequency band that can be received by the high-speed decoder 232 at the timing when the fluctuation of the DC component is detected.

  In this case, since the high-speed decoder 232 only receives a pulse at the timing when the fluctuation of the DC component is detected as the output signal O2, only the low-speed decoder 231 decodes the data. Therefore, the data analysis unit 211 receives the data decoded by the low-speed decoder 231 and analyzes the data according to the first communication speed.

  The communication control unit 212 analyzes the data as the data according to the first communication speed by the data analysis unit 211 so that the response according to the first communication speed is transmitted to the primary station. Control the device 14. Accordingly, when the communication device 20 receives data according to the modulation method of the first communication speed, the communication device 20 can reliably transmit a response to the data.

  On the other hand, as shown in FIG. 7B, when the input signal I is data in accordance with the modulation scheme of the second communication speed, the AC / DC extraction unit 243 determines the signal amount (AC component) together with the fluctuation of the DC component. Detect fluctuations. Therefore, the AC / DC extraction unit 243 outputs a pulse having the same length as the input signal I and the frame length as the output signal O1 in accordance with the fluctuation of the DC component. Further, the AC / DC extraction unit 243 outputs, as an output signal O2, a pulse modulated at the second communication speed in accordance with the fluctuation of the AC component. Note that the output signal O2 outputs a noise-like pulse until the physical layer device 14 is stabilized after the receiving unit 242 receives the data.

  In this case, the high speed decoder 232 can decode the data of the output signal O2. Therefore, the data analysis unit 211 receives the data decoded by the high-speed decoder 232 and analyzes the data according to the second communication speed.

  Then, the communication control unit 212 analyzes the data as the data according to the second communication speed by the data analysis unit 211 so that the response according to the second communication speed is transmitted to the primary station. Control the device 14. Accordingly, when the communication device 20 receives data according to the modulation method of the second communication speed, the communication device 20 can reliably transmit a response to the data.

  That is, the communication device 20 receives a communication frame composed of “PA”, “STA”, “Data”, “CRC”, and “STO” as data according to the modulation scheme of the second communication speed from the primary station. In addition, the high-speed decoder 232 can decode the communication frame. Therefore, the data analysis unit 211 can analyze the pulse as the output signal O2 as a communication frame including “PA”, “STA”, “Data”, “CRC”, and “STO”.

  As described above, the data analysis unit 211 extracts data by the AC / DC extraction unit 243 even when the reception unit 242 receives data according to any modulation method of the first communication speed and the second communication speed. Based on the DC component and AC component, it is possible to determine which modulation method is used for the data. For this reason, when the communication device 20 recognizes (searches) the secondary station at the primary station, the communication pattern of the first communication speed from the existing communication device according to the current IrDA system, The communication frame of the second communication speed from the communication device 10 can be waited simultaneously.

  Accordingly, the communication device 20 receives the communication frame of the second communication speed from the communication device 10 and performs connection processing, or receives the communication pattern of the first communication speed from the existing communication device and connects. It is also possible to perform processing. That is, the communication device 20 can maintain compatibility with a communication device in accordance with an existing communication method, and if the primary station is the communication device 10, the connection time until the start of communication can be shortened.

  Note that when the communication device 20 receives a communication frame at the second communication speed from the communication device 10, it is preferable to transmit a response to the communication frame within a time corresponding to T2 in FIG. As a result, the communication device 10 can reliably receive the response from the communication device 20 and shift to a connection process (communication capability exchange phase or data exchange phase) with the communication device 20.

  Note that the AC / DC extraction unit 243 performs output corresponding to the modulation schemes of the first communication speed and the second communication speed, but is not limited thereto, and performs output corresponding to other modulation schemes of the communication speed. May be.

  In this case, it is assumed that the communication device 20 includes a decoder and an encoder that can correspond to the other communication speed modulation methods, and the data analysis unit 211 and the communication control unit 212 can also be supported. Further, when it is not necessary to perform the simultaneous standby as described above (for example, in the data exchange phase), the communication control unit 212 controls the communication speed in accordance with the received data.

  In the above description, the communication device 10 as the primary station and the communication device 20 as the secondary station have been described. However, the present invention is not limited to this, and the communication device 1 has both the communication devices 10 and 20. Also good. That is, the communication device 10 as the primary station may have the configuration of the communication device 20, and the communication device 20 as the secondary station may have the configuration of the communication device 10.

[Supplement]
Finally, each block of the communication devices 1, 10, and 20 according to the present embodiment, particularly the control unit 11 (selection control unit 111, reception state switching unit 112, reception state monitoring unit 113, communication control unit 114, data analysis unit 211. The communication control unit 212) may be configured by hardware logic, or may be realized by software using a CPU as follows.

  That is, the communication devices 1, 10, and 20 according to this embodiment include a CPU (Central Processing Unit) that executes instructions of a control program that realizes each function, a ROM (Read Only Memory) that stores the program, and the program. A RAM (Random Access Memory) to be developed, a storage device (recording medium) such as a memory for storing the program and various data, and the like are provided. The object of the present invention is to record the program code (execution format program, intermediate code program, source program) of the control program of the communication devices 1, 10, and 20, which is software that realizes the above-described functions, in a computer-readable manner This can also be achieved by supplying a recording medium to the communication devices 1, 10, and 20, and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).

  Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and disks including optical disks such as CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  The communication devices 1, 10, and 20 according to the present embodiment may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

[Another expression of the present invention]
The present invention can also be expressed as follows.

  That is, the communication method according to the present invention is a communication device having two or more types of communication speeds at which communication is possible. Exchange the communication capabilities of devices such as speed, time interval between communication frames, timeout in case of communication interruption, etc., and connect the upper layer at the best (high) second communication speed from the communication speed of the exchanged communication capacity In a communication method for exchanging data, a communication frame modulated at a second communication speed is output instead of a pulse signal at the timing of a pulse signal modulated and output at a first communication speed.

  The communication method according to the present invention outputs a communication frame modulated at the second communication speed instead of the pulse signal at the timing of the pulse signal modulated and output at the first communication speed, and then outputs the next frame. It is preferable to transit to a state in which a frame modulated at the second communication speed is received from an output timing or a time from the start of communication of the communication frame to the end of one bit time of the first communication speed.

  In the communication method according to the present invention, when the frame modulated at the second communication speed is received in the state of receiving the frame modulated at the second communication speed, the second communication speed is set. It is preferable to use it to perform connection processing.

  The communication method according to the present invention preferably transitions to a state in which a communication frame having the first communication speed is received after outputting the communication frame having the first communication speed, including the second communication frame.

  In addition, the communication method according to the present invention is a communication device having two or more types of communication speeds capable of communication, and communication in communication (communication between a partner device and data of the partner device at the first communication speed). Exchange the communication capabilities of devices such as speed, time interval between communication frames, timeout in case of communication interruption, etc., and connect the upper layer at the best (high) second communication speed from the communication speed of the exchanged communication capacity Or in a communication method for exchanging data, when a communication pulse modulated at the first communication speed and a communication frame modulated at the second communication speed are received simultaneously and a communication frame at the second communication speed is received. Performs the connection process at the second communication speed, and performs the connection process at the first communication speed when receiving the communication frame at the first communication speed without receiving the communication frame at the second communication speed. .

  The communication method according to the present invention is a short-distance communication device having two or more types of communication speeds at which communication is possible. At the first communication speed, the partner device is recognized (searched), and the partner device and the data Exchange the communication capabilities of devices such as communication speed, time interval between communication frames, timeout when communication is interrupted, etc., and the highest (high) second communication speed is the highest from the communication speed of the exchanged communication capacity In a communication method for connecting layers and exchanging data, a communication frame modulated at a second communication speed is output instead of a pulse signal at the timing of a pulse signal modulated and output at a first communication speed.

  The communication method according to the present invention is a short-distance communication device having two or more types of communication speeds at which communication is possible. At the first communication speed, the partner device is recognized (searched), and the partner device and the data Exchange the communication capabilities of devices such as communication speed, time interval between communication frames, timeout when communication is interrupted, etc., and the highest (high) second communication speed is the highest from the communication speed of the exchanged communication capacity In a communication method for connecting layers and exchanging data, a communication pulse modulated at the first communication speed and a communication frame modulated at the second communication speed are received simultaneously, and a communication frame at the second communication speed is received. If a communication frame of the first communication speed is received without receiving the communication frame of the second communication speed, the connection processing is performed at the first communication speed. Processing Masui.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The present invention can be suitably used particularly for communication devices having an optical space communication function, for example, portable wireless communication devices such as notebook PCs, PDAs, mobile phones, and digital cameras.

1, 10, 20 Communication device 112 Reception state switching unit (reception state switching means)
114 Communication control unit (first communication control means)
131 Low speed encoder (first data converter)
132 High-speed encoder (second data converter)
133 Multiplexer (output unit)
141 Transmitter (output unit)
212 Communication control unit (second communication control means)

Claims (11)

According to the modulation method of the first communication speed, search and recognition of the secondary station that is the communication partner and exchange of the communication capability with the secondary station, the upper layer according to the second communication speed higher than the first communication speed Communication equipment as a primary station that performs connection and data exchange with a secondary station,
A first data converter that converts the data to be output to the secondary station into first communication data according to the modulation method of the first communication speed;
When one pulse of the first communication data converted by the first data converter is received, the data to be output to the secondary station is the second data having a data length corresponding to the pulse width of the one pulse. A second data conversion unit for converting into second communication data according to a modulation method of communication speed;
An output unit that outputs the second communication data converted by the second data conversion unit to the secondary station instead of one pulse of the first communication data. The reception state of the own device, the first reception state capable of receiving the first communication data according to the modulation method of the first communication speed from the secondary station, and the modulation method of the second communication speed from the secondary station Receiving state switching means for switching to a second receiving state capable of receiving the second communication data according to
The reception state switching means is configured to start outputting the second communication data instead of one pulse of the first communication data until a time corresponding to one bit of the first communication data elapses. Alternatively, the communication device according to claim 1, wherein the second reception state is maintained until output of a next pulse of the first communication data is started. Comprising first communication control means for controlling connection processing with the secondary station,
When the first communication control means receives a response to the second communication data from the secondary station while the reception state switching means is in the second reception state, the second communication speed modulation method The communication device according to claim 2, wherein connection processing is performed in accordance with the communication device.   When the time corresponding to the pulse width of one pulse of the first communication data has elapsed since the last pulse of the first communication data including the second communication data is output, The communication device according to claim 2, wherein the communication device is switched to a first reception state. According to the modulation method of the first communication speed, the primary station searches for and recognizes its own device, and exchanges the communication capability with the primary station. According to the second communication speed higher than the first communication speed, the upper layer connection and A communication device as a secondary station that exchanges data with the primary station,
When the first communication data according to the first communication speed modulation method is received, connection processing with the primary station is performed according to the first communication speed modulation method, and one pulse pulse of the first communication data A communication device comprising second communication control means for performing connection processing with the primary station in accordance with a second communication speed modulation method when receiving second communication data having a data length corresponding to a width. According to the modulation method of the first communication speed, search and recognition of the secondary station that is the communication partner and exchange of the communication capability with the secondary station, the upper layer according to the second communication speed higher than the first communication speed Communication method of a communication device as a primary station that performs connection and data exchange with a secondary station,
A first data conversion step of converting data to be output to the secondary station into first communication data in accordance with the modulation method of the first communication speed;
When one pulse of the first communication data converted by the first data conversion step is received, the data to be output to the secondary station is the second data having a data length corresponding to the pulse width of the one pulse. A second data conversion step for converting to second communication data according to a modulation method of communication speed;
An output step of outputting the second communication data converted by the second data conversion step to the secondary station in place of one pulse of the first communication data. According to the modulation method of the first communication speed, the primary station searches for and recognizes its own device, and exchanges the communication capability with the primary station. According to the second communication speed higher than the first communication speed, the upper layer connection and A communication method of a communication device as a secondary station for exchanging data with a primary station,
When the first communication data according to the first communication speed modulation method is received, connection processing with the primary station is performed according to the first communication speed modulation method, and one pulse pulse of the first communication data A communication method characterized in that when receiving second communication data having a data length corresponding to a width, connection processing with the primary station is performed according to a modulation method of a second communication speed.   The communication device according to any one of claims 1 to 4, wherein the communication device communicates with a secondary station existing at a short distance by infrared rays.   6. The communication apparatus according to claim 5, wherein communication is performed with a primary station existing at a short distance by infrared rays. According to the modulation method of the first communication speed, search and recognition of the secondary station that is the communication partner and exchange of the communication capability with the secondary station, the upper layer according to the second communication speed higher than the first communication speed A communication device control program as a primary station for performing connection and data exchange with a secondary station,
A first data conversion process for converting data to be output to the secondary station into first communication data according to the modulation method of the first communication speed;
When one pulse of the first communication data converted by the first data conversion process is received, the data to be output to the secondary station is the second data having a data length corresponding to the pulse width of the one pulse. A second data conversion process for converting to second communication data according to a modulation method of communication speed;
Control of communication equipment for causing a computer to execute output processing for outputting the second communication data converted by the second data conversion processing to the secondary station instead of one pulse of the first communication data program. According to the modulation method of the first communication speed, the primary station searches for and recognizes its own device, and exchanges the communication capability with the primary station. According to the second communication speed higher than the first communication speed, the upper layer connection and A communication device control program as a secondary station for exchanging data with the primary station,
When the first communication data according to the first communication speed modulation method is received, connection processing with the primary station is performed according to the first communication speed modulation method, and one pulse pulse of the first communication data A control program for a communication device for causing a computer to execute a process of performing a connection process with the primary station according to a modulation method of a second communication speed when receiving second communication data having a data length corresponding to a width.

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