JP2000196652A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network system capable of housing an information terminal to a line concentrator in a non-contact manner without being involved in the change, etc., of communication protocols. SOLUTION: In this network system, a newly provided repeater 20 is intervened between a portable information terminal 10 and a hub which are directly connected by a cable in the conventional practice, and the terminal 10 and the repeater 20 are respectively provided with optical space transmitting devices 14 and 21 for performing optical communication. And, it is possible to show to the CPU 11 of the terminal 10 and the hub 30 as if they are connected by a cable as in the conventional practice by converting an electric signal into an optical signal between the terminal 10 and the repeater 20, transferring it by a radio channel and then, converting an optical signal into an electric signal again after once converting. It is possible to make the terminal 10 to be housed in the hub 30 in a non-contact manner without being involved in the change, etc., of a communication protocols at all.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system for accommodating a plurality of information terminals by concentrators scattered on a computer network, and more particularly, to a non-contact information terminal without changing a communication protocol. The present invention relates to a network system that can be accommodated in a line concentrator.

[0002]

2. Description of the Related Art In recent years, for example, PDA (Persona)
Various types of portable information terminals, such as l Digital Assistants terminals, which can be driven by a battery and are easy to carry, have been developed. In addition, the improvement of network technology is remarkable, and the local area network (LA)
N: Local Area Network has been laid.

In such offices, while in the office, a portable information terminal is connected to a local area network to enable data communication with other portable information terminals and use of shared system resources such as a printer. When you do
It is common to take necessary data or the like and then carry the portable information terminal away from the local area network.

[0004]

By the way, the connection of the portable information terminal to the local area network is performed by a line concentrator called a hub or the like scattered on the local area network to accommodate the information terminal in the local area network. And a portable information terminal by a cable.

[0005] Therefore, the user must connect the cable to the connector of his / her portable information terminal when returning from the place where the user is going. On the other hand, when carrying the user when going out, the user must remove the cable from the connector. Had to be done.

[0006] Frequent connection / removal of a cable to / from such a connector significantly shortens the life of the connector.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a network system that can accommodate an information terminal in a concentrator without contact without changing a communication protocol. Aim.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, according to the present invention, instead of directly connecting a concentrator and an information terminal with a cable, a newly provided relay device and concentrator are provided. A connection is made by a cable, and the relay device and the information terminal are connected by a wireless line by optical communication. Then, in order to make the information terminal appear to be connected to the concentrator by a cable as in the conventional case, the information terminal outputs the data from the network controller (which controls data transfer between the CPU and the computer network). A first optical space transmission device for converting the converted electrical signal into an optical signal and transferring the converted optical signal to the relay device, converting the optical signal transferred from the relay device into an electrical signal, and inputting the converted electrical signal to a network controller; A second optical space that converts an optical signal transferred from the information terminal into an electric signal and transfers the signal to the concentrator, and converts an electric signal transferred from the computer network into an optical signal and transfers the signal to the information terminal; A transmission device is provided.

According to the present invention, since the information terminal can be accommodated in the concentrator without contact without changing the communication protocol, the user connects / disconnects the cable to / from the connector. This eliminates the need to do so, which also prevents the life of the connector from being shortened.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a connection form between devices in a network system according to an embodiment of the present invention.

As shown in FIG. 1, this network system accommodates a portable information terminal 10 in a hub 30 via a relay device 20.
By connecting with 0, for example, data communication between the portable information terminals 10 and the like are enabled. The feature of the present invention is that the conventional portable information terminal 10
Where the cable and the hub 30 were directly connected,
By connecting the newly installed relay device 20 and the hub 30 with a cable and connecting the relay device 20 and the portable information terminal 10 by a wireless line, the portable information terminal 10 can be accommodated in the hub 30 without contact. It is in the point. Further, by making the portable information terminal 10 appear to be connected to the hub 30 by a cable as in the related art, there is no change in the communication protocol. Hereinafter, this point will be described in detail with reference to FIG.

FIG. 2 is a diagram showing the configuration of the portable information terminal 10 and the relay device 20 of this network system.

As shown in FIG. 2, a portable information terminal 10 of this network system includes a CPU 11, a system bus 12, a LAN controller 13, and an optical space transmission device 1.
4, while the relay device 20 includes an optical space transmission device 21 and a repeater 22.

(Portable Information Terminal 10) The CPU 11 controls the entire portable information terminal 10. The system bus 12 is a data transfer path used for communication between the CPU 11 and various I / O devices including the LAN controller 13. The LAN controller 13 is connected to the system bus 12
Is one of I / O devices connected to the CPU 11
This is for controlling data transfer between the LAN and the LAN 100. The LAN controller 13 has a data link controller (DTE) 131 and a transceiver (MAU) 132.

The data link controller 131 has a CP
U11 has a function of taking in transmission data output on the system bus 12 and a function of outputting reception data to the CPU 11 on the system bus 12. On the other hand, the transceiver 132 has a transmission control function for transmitting transmission data fetched by the data link controller 131 to the LAN 100 and a reception control function for transferring reception data transferred via the LAN 100 to the data link controller 131. . Note that this LAN controller 13
Describes the data exchange with the LAN 100 as “System
Considation for Multis
element 10 Mb / s Baseband N
etworks (Section 13) Twist
ed Pair Medium Attachment
Unit (MAU) and Baseband Me
, type 10 Base-T (Secti
on 14) ", the data link controller 131 and the transceiver 132 communicate with signal lines (DO +, DO) for transmitting and receiving transmission data.
−), A signal line (DI +, D
I-) and a signal line (CI +, CI-) for notifying that transmission of transmission data and reception of reception data have collided.
Connected by From the transceiver 132, a signal line (TD) for outputting transmission data and a signal line (RD +, RD-) for inputting reception data are led out to the optical free space transmission device 14.

The optical free space transmission device 14 converts the transmission data output from the transceiver 132 of the LAN controller 13 from an electric signal to an optical signal and transfers it to the relay device 20, and also converts the reception data transferred from the relay device 20. The LAN controller 13 converts the optical signal into an electric signal and converts the signal into an electric signal.
To the LED drive circuit 141,
It has an LED 142, a PD 143, a photoelectric conversion unit 144, and a voltage comparison unit 145.

The transmission data (electric signal) from the LAN controller 13 is supplied to an LED driving circuit 141, and the LED driving circuit 141
The transmission data is transferred to the relay device 20 by light by controlling the driving of the transmission device 2. On the other hand, the received data (optical signal) from the relay device 20 is taken in by the PD 143 as a light receiving element, and the photoelectric conversion unit 144 and the voltage comparison unit 14
5 is converted into an electric signal by the LAN controller 13
Is input to

(Relay device 20) The optical space transmission device 21
The transmission data transferred from the portable information terminal 10 is converted from an optical signal to an electric signal and input to the repeater 22, and the received data output from the repeater 22 is converted from an electric signal to an optical signal and transmitted to the portable information terminal 10. It is for transferring, and includes a PD 211, a photoelectric conversion unit 212, a voltage comparison unit 213, and an LED drive circuit 214.

Transmission data (optical signal) from the portable information terminal 10 is captured by a PD 211 as a light receiving element.
The signal is converted into an electric signal by the photoelectric conversion unit 212 and the voltage comparison unit 213 and input to the repeater 22. On the other hand, the reception data (electric signal) from the repeater 22 is supplied to the LED driving circuit 214, and the LED driving circuit 214
By controlling the driving of the LED 215, which is a light emitting element, the received data is transferred to the portable information terminal 10 by light.

The repeater IC 22 is a circuit for shaping transmission data and reception data signals.

As described above, there is a configuration for once converting an electric signal into an optical signal between the portable information terminal 10 and the relay device 20, transferring the signal through a wireless line, and then converting the optical signal into an electric signal again. Accordingly, in this network system, the CPU 11 of the portable information terminal 10 and the hub 3
0 can be made to appear as if they were connected by a cable as in the past, and the portable information terminal 10 can be contactlessly connected to the hub 3 without any change in the communication protocol.
0, which can prevent the connector from being shortened.

Next, a modification of the network system will be described with reference to FIG. FIG. 3 is a diagram illustrating the configurations of the portable information terminal 10 and the relay device 20 of the network system according to the modification.

The difference between the configuration of the portable information terminal 10 and the relay device 20 shown in FIG. 3 and the configuration of the portable information terminal 10 and the relay device 20 shown in FIG.
And a transmission control function for transmitting the received data to the data link controller 13.
In this embodiment, a transceiver 23 having a reception control function for delivering the data to the LAN controller 13 is provided in the relay device 20 instead of the LAN controller 13. In such a configuration, the format of the data that should be input / output by the portable information terminal 10 and the format of the data that is actually input / output are different, but the difference is visible to the CPU 11 and the hub 30 of the portable information terminal 10. There is no problem at all, and the number of members of the portable information terminal 10 to be carried can be reduced. Therefore, the size and weight of the casing of the portable information terminal 10 can be reduced, and the ease of carrying can be further improved. It is possible to increase.

[0025]

As described above in detail, according to the present invention, the information terminal side appears to be connected to the line concentrator by a cable as in the prior art, and the line concentrator and the information terminal are connected by the cable. Instead of connecting directly, connect the newly installed relay device and concentrator with a cable,
By connecting this relay device and the information terminal via a wireless line by optical communication, it is possible to accommodate the information terminal in the concentrator without contact without changing the communication protocol, etc. By eliminating the need to connect or disconnect the cable, it is possible to prevent the life of the connector from being shortened.

[Brief description of the drawings]

FIG. 1 is an exemplary view showing a connection form between devices in a network system according to an embodiment of the present invention.

FIG. 2 is an exemplary view showing a configuration of a portable information terminal and a relay device of the network system according to the embodiment.

FIG. 3 is an exemplary view showing a configuration of a portable information terminal 10 and a relay device 20 of a network system according to a modification of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Portable information terminal 11 ... CPU 12 ... System bus 13 ... LAN controller 14 ... Optical space transmission device 20 ... Relay device 21 ... Optical space transmission device 22 ... Repeater 23 ... Transceiver 30 ... Hub 100 ... LAN 131 ... Data link controller ( DTE) 132 Transceiver 141 LED drive circuit 142 LED 143 PD 144 Photoelectric conversion unit 145 Voltage comparison unit 211 PD 212 Photoelectric conversion unit 213 Voltage comparison unit 214 LED drive circuit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04B 10/22

Claims (3)

[Claims] 1. A network system in which a plurality of information terminals are accommodated by concentrators scattered on a computer network, wherein a relay device is interposed between the concentrator and the information terminal, the information terminal comprising: a CPU; A network controller that controls data transfer between the CPU and the computer network, and converts an electric signal output from the network controller into an optical signal and transfers the optical signal to the relay device;
A first optical space transmission device that converts an optical signal transferred from the relay device into an electric signal and inputs the converted signal to the network controller, wherein the relay device converts the optical signal transferred from the information terminal into an electric signal. And a second optical space transmission device for converting the electrical signal transferred from the computer network into an optical signal and transferring the converted signal to the information terminal, while converting the communication protocol into a signal. A network system in which the information terminal can be accommodated in the line concentrator without contact without any other factors. 2. A network controller comprising: a data link controller for controlling data transfer with the CPU; a transmission control for transmitting transmission data output from the data link controller to the computer network; and the computer network. 2. The network system according to claim 1, further comprising a transceiver for performing reception control for inputting received data transferred via the data link controller to the data link controller. 3. The network controller is provided with a data link controller for controlling data transfer with the CPU, and the relay device transmits transmission data output from the data link controller to the computer network. A transceiver for performing control and receiving control for inputting received data transferred via the computer network to the data link controller is provided between the second optical space transmission device and the concentrator. The network system according to claim 1, wherein the network system is provided.