JP2005033296A - Protocol conversion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protocol conversion apparatus capable of converting a plurality of communication protocols. <P>SOLUTION: This protocol conversion apparatus is provided with two or more interfaces for accommodating communication protocols different depending on devices, a communication protocol specifying means for specifying the communication protocol of a communication destination on the basis of communication destination identifying information contained in a reception signal received from any one of the communication interfaces, and a protocol adjusting means for matching the communication protocol of the reception signal with the specified communication protocol and delivering the matched communication protocol to a communication interface making communication by that communication protocol. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a protocol conversion device, and is suitable for application to an access point (AP) device that relays communication between, for example, a wireless LAN and a wired LAN or infrared rays.
[0002]
[Prior art]
In Patent Document 1, a wireless LAN device connected to a computer via a wireless LAN port has a protocol conversion unit that mutually converts a protocol between an optical signal and a USB signal, and receives an optical signal from an optical signal input device. In the case of wireless communication, the protocol conversion unit first applies a USB signal whose protocol has been converted to a computer, then gives a signal from the computer to the wireless LAN device, and wirelessly communicates with the wireless LAN device to which the opposite computer is connected, A technique for transferring data is described.
[0003]
[Patent Document 1]
JP 2000-200122 A
[0004]
[Problems to be solved by the invention]
However, the conventional wireless LAN device including Patent Document 1 always requires a personal computer when a device that communicates by wire and infrared uses a wireless LAN. Therefore, the number of devices and parts for performing protocol conversion increases. There is a problem that the failure rate and the cost increase from the whole system.
[0005]
Therefore, even a device that does not have a wireless communication function can perform wireless communication without using a personal computer, and can convert a plurality of different wired or infrared communication protocols and convert them to a wireless communication protocol. A device is sought.
[0006]
[Means for Solving the Problems]
In order to solve such a problem, the protocol conversion device of the present invention is included in two or more communication interface units having different communication protocols of the devices accommodated therein and a received signal received from one of the communication interface units. Based on the communication destination identification information, the communication protocol specifying means for specifying the communication protocol of the communication destination and the communication protocol of the received signal are matched with the specified communication protocol and delivered to the communication interface unit that communicates with the communication protocol. And a protocol adjustment means.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
(A) Embodiment
Hereinafter, an embodiment of a protocol conversion apparatus of the present invention will be described with reference to the drawings.
[0008]
In the present embodiment, a case will be described in which a case where a device that does not have a wireless communication function is connected to a protocol conversion device and connection to a wireless LAN system is realized using the protocol conversion device is described.
[0009]
(A-1) Configuration of the embodiment
FIG. 1 is a block diagram showing the internal configuration of the protocol conversion apparatus according to this embodiment. FIG. 2 shows a system configuration for performing wireless communication using the protocol conversion apparatus of the present embodiment.
[0010]
First, the internal configuration of the protocol conversion apparatus according to the present embodiment will be described with reference to FIG.
[0011]
As shown in FIG. 1, the protocol conversion device 2 according to this embodiment includes a connection port 20A to 20D that connects devices A to D that communicate with a plurality of different communication protocol standards, and a device A that connects to each connection port 20A to 20D. Port control units 21A to 21D for controlling communication with D, a protocol conversion unit 22, a wireless LAN control unit 23, and a wireless LAN device 24.
[0012]
The protocol conversion device 2 has a role as an access point in the wireless LAN system, and executes wireless LAN communication (for example, IEEE802.11b communication protocol) with the access point 3 in FIG. 2 as will be described later. Thus, connection to a LAN network is made possible.
[0013]
In FIG. 1, the protocol conversion device 2 is connected to devices A to D via connection ports 20A to D.
[0014]
The devices A to D are devices that communicate with different communication protocol standards, the device A is a wired LAN standard communication protocol (for example, IEEE 802.3), the device B is a RS232-C standard communication protocol, and the device C is a The communication protocol for enabling USB communication and the device D execute communication with a communication protocol for enabling infrared communication, respectively.
[0015]
Further, the devices A to D correspond to personal computer peripheral devices such as a data input device such as a mouse and a keyboard, a data output device such as a printer, a speaker, and a display, and an image input device such as a scanner and a digital camera.
[0016]
The connection ports 20A to 20D are connection ports that connect to devices A to D that communicate with different communication protocol standards. In the present embodiment, the connection ports 20A to 20D are a LAN port 20A, an RS232-C port 20B, a USB port 20C, and an infrared port 20D that are connected to a device A that can communicate with a wired LAN communication protocol. Of course, you may make it connect with the apparatus which communicates with another communication protocol.
[0017]
The port control units 21A to 21D are communication drivers (which may be configured by hardware, for example) that process communication using communication protocols connected to the connection ports 20A to 20D, and mainly correspond to the physical layer of the OSI reference model. It has a function. In addition, when the devices A to D are connected via the connection ports 20A to 20D, the port controllers 21A to 21D allocate and manage the port numbers of the connected devices A to D, respectively.
[0018]
For example, when the devices A to D are connected to the port controllers 21A to 21D, attribute information for recognizing which device is the device A to D (for example, connection form, communication speed, etc.) ) Are transmitted to the devices A to D, and the attribute information and the port number received from the devices A to D are associated with each other and managed accordingly.
[0019]
The port control units 21A to 21D identify the port number included in the header portion of the signal received from the protocol conversion unit 22 when the reception signals received by the wireless LAN communication are given to the devices A to D, and the ports This is given to the devices A to D corresponding to the numbers.
[0020]
Of course, the number of devices A to D that can be connected to each connection port 20A to 20D may be such that a plurality of devices are connected to one connection port.
[0021]
In the present embodiment, as the port control units 21A to 21D, a LAN port control unit 21A, an RS232-C control unit 21B, a USB control unit 21C, and an infrared port control unit 21D are shown.
[0022]
The LAN port control unit 21 is connected to the device A via the wired LAN port 20A. The LAN port control unit 21 gives the received signal received from the device A to the protocol conversion unit 25. The LAN port control unit 21 provides a signal from the protocol control unit 25 to the device A via the wired LAN port 20A.
[0023]
The RS232-C port control unit 22 is connected to the device B via the RS232-C port 20B. The RS232-C port control unit 22 gives a reception signal received from the device B to the protocol conversion unit 25, and gives a signal from the protocol conversion unit 25 to the device B via the RS232-C port 20B.
[0024]
The USB port control unit 23 is connected to the device C via the USB port 20C. The USB port control unit 23 gives a reception signal received from the device C to the protocol conversion unit 25, and gives a signal from the protocol conversion unit 25 to the device C through the USB port 20C.
[0025]
The infrared port control unit 24 is connected to the device D via the infrared port 20D. The infrared port control unit 24 gives a reception signal received from the device D to the protocol conversion unit 25, and gives a signal from the protocol conversion unit 25 to the device D via the infrared port 20D.
[0026]
The protocol conversion unit 22 performs protocol conversion between the wireless LAN control unit 23 and any one of the port control units 21A to 21D. The protocol conversion unit 22 is mainly a data link of the OSI reference model. In addition to having a function corresponding to the layer, relay processing is also performed in an upper layer corresponding to the vicinity of the application layer of the OSI reference model.
[0027]
The relay processing in the upper layer near the application layer by the protocol conversion unit 22 is performed, for example, when determining a difference in USB transfer mode or the like. The USB transfer mode includes, for example, an isochronous transfer mode, a bulk transfer mode, and the like, and is a mode that regulates the amount of communication transferred per unit time for USB communication. Of course, the present invention is not limited to this, and the protocol conversion unit 22 determines information related to the devices A to D included in the vicinity of the application layer related to transfer, and controls to transfer according to the information.
[0028]
The protocol conversion unit 22 has a destination management table for managing destinations included in the header of the converted signal, and controls the destinations with reference to the destination management table.
[0029]
The protocol conversion unit 22 includes a function for mutual conversion between the wireless LAN communication protocol and the wired LAN communication protocol, a function for mutual conversion between the wireless LAN communication protocol and the RA232-C communication protocol, a wireless LAN communication protocol, and a USB communication protocol. It has a function for mutual conversion and a function for mutual conversion between the wireless LAN communication protocol and the infrared communication protocol. These functions are preset in the protocol conversion unit 22, and may be executed by, for example, a control unit (not shown) included in the protocol conversion device 2 itself.
[0030]
For example, the protocol conversion unit 22 needs to perform a switch operation for distributing a reception signal received from the wireless LAN device 24 to an appropriate port control unit (for example, 20A).
[0031]
The received signal to be distributed (referred to as frame FR1) includes four fields F1 to F4 shown in FIG.
[0032]
Of the fields F1 to F4, the physical layer header F1 is a header that contains identification information (such as ESS-ID) for designating the protocol converter 2, and is specific to the wireless LAN.
[0033]
The MAC header F2 is a MAC header unique to the wireless LAN. The MAC header F2 includes the MAC address of the protocol converter 2 in addition to the destination MAC address that specifies the same destination device as the normal MAC header used on the wired LAN network 6 and the source MAC address that specifies the source device. The address is described.
[0034]
The protocol header F3 is a header corresponding to the communication protocol of the network to which the final destination devices A to D belong. For example, if IP is used in the network layer of the OSI reference model in the network to which the device A belongs (corresponding to the left side of the connection port 21A in FIG. 1), the protocol header F3 becomes an IP header. If necessary, a header (for example, a TCP header or a UDP header) may be arranged on the right side of the protocol header F3.
[0035]
User data F4 is data that a predetermined communication application intends to transmit. Assuming e-mail, for example, as the communication application, the contents of e-mail (e-mail header, e-mail body, attached file, etc.) correspond to this user data F4.
[0036]
The physical layer header F1 is used only on the wireless LAN network 6, and the MAC header F2 is replaced when the protocol conversion device 2 performs relay processing. Therefore, the protocol conversion device 2 among the fields F1 to F4. The fields that are unchanged before and after the relay processing in FIG. 5 are a protocol header F3 and user data F4.
[0037]
When the protocol converter 22 receives such a frame FR1, it is necessary to specify a communication protocol corresponding to the frame FR1 in order to perform the above-described sorting.
[0038]
When the protocol conversion unit 22 can identify the communication protocol by analyzing the MAC header F2 and the protocol header F3, the protocol conversion unit 22 can use the normal frame as it is as the frame FR1.
[0039]
However, if this is impossible or difficult, the physical layer header F1 and the MAC header F2 are expanded or a new header is inserted into the frame FR1 (for example, the MAC header F2 and the protocol header F3). For example, it is necessary to be able to describe information for specifying the distribution destination. As described above, when the headers F1 and F2 are expanded or a new header is inserted, the access point 3 facing the protocol conversion device 2 is also equipped with functions corresponding to such expansion and new header. Of course you need to do.
[0040]
The frame configuration transferred from the protocol conversion device 2 to the access point 3 is the same as described above.
[0041]
The protocol conversion unit 22 divides the signal received from the wireless LAN control unit 23 into a header part and data, and based on the destination information included in the header part, the port numbers of the destination devices A to D Are given to the port control units 21A to 21D corresponding to the devices A to D. The protocol conversion unit 22 identifies the port number included in the header portion of the signal received from the protocol conversion unit 22 when the signal received by the wireless LAN communication is given to each of the devices A to D, and corresponds to the port number. To the port control units 21A to 21D. Further, after determining the port number, the protocol conversion unit 22 extracts the attribute information corresponding to the port number and converts the protocol so that communication according to the attribute information is performed.
[0042]
Conversely, the protocol conversion unit 22 receives signals from the devices A to D via the port control units 21A to 21D when transferring signals from the devices A to D using the wireless LAN system. The IP address of the destination device is assigned to the user data of the signals of the devices A to D, and is given to the wireless LAN control unit 23.
[0043]
The wireless LAN control unit 23 is a wireless communication driver, for example, and mainly processes the physical layer of the OSI reference model. The wireless LAN control unit 23 receives a protocol-converted signal from the protocol conversion unit 22 and provides the signal to the wireless LAN device 24. The wireless LAN control unit 23 receives a signal from the wireless LAN device 24 and supplies it to the protocol conversion unit 22.
[0044]
In addition, when the wireless LAN control unit 23 detects detection data included in the received data portion received from the protocol conversion unit 22, the wireless LAN control unit 23 sends the received data back to the protocol conversion unit 22 without giving it to the wireless LAN device 24. It is. Thereby, communication between the apparatuses A to D connected to the protocol conversion apparatus 2 can also be enabled.
[0045]
The wireless LAN device 24 is a portion corresponding to, for example, a LAN card for wireless LAN, and mainly processes the physical layer of the OSI reference model in order to perform wireless LAN communication.
[0046]
Next, a wireless LAN system using the protocol conversion device 2 of this embodiment will be described with reference to FIG. FIG. 2 is a system configuration diagram showing a wireless LAN system using the protocol conversion device 2.
[0047]
In FIG. 2, the data output device 4 and the signal processing device 5 indicate elements constituting the LAN network 6.
[0048]
In addition, the protocol conversion device 2 of the present embodiment can perform communication between the devices A to D and each element of the LAN network 6 by performing wireless communication with the access point 3 that can be connected to the LAN network 6. it can.
[0049]
In the present embodiment, the LAN network 6 is a network that uses a wireless LAN, but is not limited thereto, and may be a network that uses, for example, a wired LAN or the Internet.
[0050]
The access point 3 is an existing service point connected to the LAN network 6, and performs wireless communication with the protocol conversion device 2 to exchange data. An existing access point 3 can be applied, and is generally a kind of bridge, and performs relay processing in the data link layer of the OSI reference model. In this relay process, the access point 3 absorbs physical layer differences (for example, wired and wireless differences) of the OSI reference model and does not process any lower layers above the network layer, and passes them transparently. Only. Therefore, the access point 3 does not perform processing using the control information in the IP header even if the IP address corresponding to the network layer of the OSI reference model is included.
[0051]
The data output device 4 communicates with the devices A to D, and corresponds to, for example, a display or a printer.
[0052]
The signal processing device 5 communicates with the devices A to D, and corresponds to, for example, a personal computer.
[0053]
(A-2) Operation of the embodiment
Next, the operation of the protocol conversion apparatus 2 according to the present embodiment will be described with reference to FIG.
[0054]
First, the protocol conversion device 2 converts the protocol of the wired LAN signal from the device A (here, a signal input device), and provides the signal processing device 5 with the wireless LAN communication by TCP to the signal processing device 5. FIG. The description will be given with reference.
[0055]
The protocol conversion device 2 establishes a TCP connection with the signal processing device 5 via the access point 3 in advance.
[0056]
The wired LAN signal input in the device A is output from the device A and given to the LAN port control unit 21A via the wired LAN port 20A. The wired LAN signal given to the LAN port controller 21A is given to the protocol converter 22 (S31).
[0057]
In the protocol conversion unit 22, the wired LAN signal received from the LAN port control unit 21A is divided into a header portion and user data (S32).
[0058]
In the protocol conversion unit 22, the communication partner is determined based on the destination information included in the divided header portion, and a TCP header including the IP address of the communication partner is added to the user data (S33).
[0059]
The user data provided with the TCP header is given to the wireless LAN control unit 23 and transmitted from the wireless LAN device 24 to the access point 3 by wireless LAN communication (S34).
[0060]
The wireless LAN signal transferred from the protocol conversion device 2 in this way is given to the access point 3 and given to the signal processing device 5 on the LAN network 6.
[0061]
Next, a case where the protocol conversion device 2 receives the wireless LAN signal from the data output device 4 by performing the wireless LAN communication by UDP and gives it to the device C through the USB port 21C will be described with reference to FIG.
[0062]
In the data output device 4, a signal to which the port number assigned to each of the devices A to D in advance by the protocol conversion device 2 is output.
[0063]
An output signal from the data output device 4 is given to the access point 3 through the LAN network 6, and is given from the access point 3 to the protocol converter 2 by wireless LAN communication (S41).
[0064]
The wireless LAN signal received from the access point 3 is given to the protocol conversion device 2, subjected to signal processing by the wireless LAN device 24, and given from the wireless LAN control unit 23 to the protocol conversion unit 22.
[0065]
In the protocol converter 22, the wireless LAN signal is divided into a UDP header and user data (S42).
[0066]
The protocol conversion unit 22 determines the transfer destination connection port based on the port number included in the header portion (S43).
[0067]
Further, the protocol conversion unit 22 determines attribute information corresponding to the port number, and controls the USB port control unit 21C to perform communication according to the attribute information (S44).
[0068]
Here, for example, the protocol conversion unit 22 has a correspondence table between the port number and the device attribute information of the port number in advance, and refers to the correspondence table and follows the attribute information of the received signal. Convert to protocol.
[0069]
When the port number is determined, the protocol conversion unit 22 creates a USB header including the port number and attaches the USB header to the user data (S45).
[0070]
The USB signal shaped by the protocol conversion unit 22 is given to the USB control unit 21C, and is given to the device C by communication control of the USB control unit 21C (S46).
[0071]
The protocol conversion unit 22 has a correspondence table between the port number and the device attribute information of the port number in advance, and transfers the data according to the received signal attribute information with reference to the correspondence table.
[0072]
The device C displays based on the signal received from the USB port control unit 21C.
[0073]
Next, a case where the protocol conversion device 2 converts a wired LAN signal from the device A (for example, a signal input device) into an RS232-C signal and transmits it to the device B will be described with reference to FIG.
[0074]
That is, this is a case where signals from the devices A to D connected to the protocol conversion device 2 are transferred to other devices connected to the protocol conversion device 2 instead of performing wireless LAN communication.
[0075]
In this case, for example, the wireless LAN control unit 23 sets and manages a plurality of pieces of device information to be communicated in advance as management data (the management unit 231 in FIG. 1), and the wireless LAN control unit 23 starts from the corresponding device. Is possible based on the transmission destination information and / or transmission source information, and sent back to the protocol conversion unit 22 again without controlling the wireless LAN communication. To do.
[0076]
In FIG. 2, the wired LAN signal output from the device A (signal input device) is input to the protocol conversion device 2 and given to the LAN port control unit 21A (S51).
[0077]
The wired LAN signal given to the LAN port control unit 21A is given to the protocol conversion unit 22, and the protocol conversion unit 22 divides it into a header part and user data (S52).
[0078]
In the protocol conversion unit 22, the wired LAN signal is shaped into a protocol that enables wireless LAN communication, and is provided to the wireless LAN control unit 23 (S53).
[0079]
When the wireless LAN control unit 23 determines that the communication is a preset device-to-device communication, the wireless LAN signal is sent back to the protocol conversion unit 22 (S54).
[0080]
At this time, the wireless LAN control unit 23 assigns data to be transmitted to the RS232-C port without performing the communication control operation related to wireless communication, and the data received from the protocol conversion unit 22 is used as it is. Send back.
[0081]
The protocol conversion unit 22 that has received the data confirms that the transmission destination is the RS232-C port, shapes the data according to a format that allows the RS232-C port control unit 21B to transmit data, and RS232-C port control unit 21B. (S58). At this time, the protocol conversion unit 22 performs communication according to the above-described port number and attribute information (S55 to S57).
RS232-C port control part 21B which received data transmits data with respect to the detection signal display apparatus of the apparatus B. FIG.
[0082]
(A-3) Effects of the embodiment
As described above, according to this embodiment, an apparatus that does not have a wireless LAN communication function can perform wireless LAN communication without using a personal computer by connecting to a protocol conversion apparatus.
[0083]
Further, according to the present embodiment, communication can be performed by performing communication protocol conversion between devices that communicate with each other via wired and infrared communication, even between different communication protocols.
[0084]
(B) Other embodiments
Below, the modification of embodiment mentioned above is demonstrated.
[0085]
(B-1) In the above-described embodiment, as a communication protocol, a communication protocol for wired LAN (for example, IEEE802.3), RS232-C, USB, a communication protocol for infrared communication (for example, IrDA), and wireless LAN However, in the present invention, it is not always necessary to use these communication protocols, and other communication protocols may be used. As an example, a protocol that can communicate with the communication protocol Bluetooth (registered trademark) corresponding to the IEEE 1394 standard may be used.
[0086]
(B-2) In the above-described embodiment, the case has been described in which the protocol conversion device 2 converts the protocol and enables communication between the two devices. The protocol converter 2 may be provided with a broadcast communication function to enable broadcast communication.
[0087]
For example, the protocol conversion device 2 receives a wireless LAN communication signal, divides the wireless LAN signal into a header portion and user data, and copies user data by the number of broadcast destination devices, Broadcast communication may be made possible by giving a header portion including a port number of a report destination to each user data for communication.
[0088]
In this case, it is desirable to perform broadcast communication to devices connected to the same connection port, but broadcast communication between devices connected to different connection ports may be used.
[0089]
(B-3) Regardless of the embodiment described above, the network configuration is not limited to that shown in FIG. The LAN network 6 may be a wired LAN network or a network that can be connected by another wireless LAN network.
[0090]
In the above embodiment, the four connection ports 21A to 21D mounted on the protocol conversion device 2 all correspond to different communication protocols. However, a plurality of ports corresponding to the same communication protocol are mounted. May be. Further, the number of ports mounted on the AP device 14 may be less or more than four.
[0091]
【The invention's effect】
According to the protocol conversion device of the present invention, it is possible to mutually convert communication protocols used by devices accommodated by two or more communication interfaces.
[0092]
Further, according to the protocol conversion device of the present invention, wireless communication can be performed without being connected to a personal computer by being incorporated in a device that does not have a wireless communication function. As a result, the number of necessary devices and parts is reduced as compared with the use of a conventional personal computer, and the failure rate and cost of the entire system are also reduced.
[0093]
In addition, according to the protocol conversion apparatus of the present invention, power consumption is suppressed as compared with the case of using a personal computer, and it can be used even in an environment where a sufficient power source cannot be obtained continuously.
[Brief description of the drawings]
FIG. 1 shows an internal configuration of a protocol conversion apparatus 2 according to an embodiment.
FIG. 2 shows an overall configuration of a communication system according to an embodiment.
FIG. 3 shows a frame configuration of a received signal received by the protocol conversion unit 22 of the present embodiment.
FIG. 4 illustrates an operation of the protocol conversion unit 22 according to the embodiment.
FIG. 5 shows an operation of the protocol conversion unit 22 of the embodiment.
FIG. 6 shows an operation of the protocol conversion unit 22 of the embodiment.
[Explanation of symbols]
2 ... Protocol converter, 20A ... LAN port,
20B ... RS232-C port, 20C ... USB port,
20D: Infrared port, 21A: LAN port control unit,
21B: RS232-C port controller, 21C: USB port controller,
21D: Infrared port control unit, 22: Protocol conversion unit,
23 ... Wireless LAN control unit, 24 ... Wireless LAN device.

Claims (3)

Two or more communication interface units each having a different communication protocol of the device accommodated therein;
Communication protocol specifying means for specifying the communication protocol of the communication destination based on the communication destination identification information included in the received signal received from any of the communication interface units;
A protocol conversion device comprising: a protocol adjustment unit that matches a communication protocol of the received signal with the specified communication protocol and delivers the communication signal to the communication interface unit that communicates with the communication protocol. The protocol conversion apparatus according to claim 1, wherein at least one of the communication protocols of the two or more communication interface units is a wireless communication protocol. A communication rule for performing communication between devices connected to a communication interface that communicates with a communication protocol other than the wireless communication protocol is set in advance.
Communication rule detecting means for detecting the communication rule information included in the received signal;
The protocol adjustment unit converts the communication protocol of the received signal into a communication protocol that communicates with a communication interface other than the wireless communication interface according to detection by the communication rule detection unit. The protocol converter described.

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