JPH0621997A - Modem selection system - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency of a communication equipment by providing a selection means selecting the MODEM matched with the capability of an opposite MODEM based on the analysis result of the MODEM capability of an opposite device by means of an analysis means. CONSTITUTION:MODEMs 100 and 200 having different capacities are connected to a line through a switching means 300. The MODEMs 100 and 200 are connected with an analysis means 400 analyzing the MODEM capacity of the opposite device. Further, the analysis means is connected to a selection means 500 selecting one of the MODEM suitable for the capacity of the opposite MODEM based on the analysis result from the analysis means 400. The selection means 500 controls the switching means 300 and switches the MODEM and the line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a modem selection system,
In particular, the present invention relates to a modem selection system capable of effectively utilizing a high-performance modem in a modem selection system of a communication device having a plurality of modems having different capabilities.

[0002]

2. Description of the Related Art Heretofore, no technique has been disclosed regarding a selection method of a modem in a communication device capable of accommodating a plurality of lines and having at least two modems.

As a prior art technique, there is a technique of using two modems at the same time and performing high-speed communication as disclosed in Japanese Patent Laid-Open No. 3-62767. However, this technique is intended only to use two modems at the same time, and does not relate to a modem selection method.

In the future, it will have a plurality of modems with different capabilities,
A communication device capable of accommodating a plurality of lines, such as a facsimile device, is considered. In this device, operation with high transmission efficiency can be performed depending on the configuration of the modem selection system.
On the contrary, there is also the possibility of inefficient operation.

As a modem selection method for a communication device having a plurality of modems having different capabilities and capable of accommodating a plurality of lines, it is generally the most empty mode among the available modems at the start of communication. It is conceivable to select a high-capacity one and use the modem and line fixedly connected during use.

FIG. 8 is a flow chart showing an outline of a transmission operation of a facsimile which can accommodate such a plurality of lines. In the figure, except for step S40, CCITT
Recommendation T. This is the same as the conventionally known one-line facsimile standardized by 30.

When there is a transmission request from the facsimile apparatus, first in step S40, the facsimile control unit selects the modem having the highest transmission capacity from the modems that are not currently used. In step S41, the facsimile machine makes a call using the selected modem. In step S42, the capability, that is, the transmission mode, of the modem on the other end is determined by the digital identification signal (DIS: indicating the receiving capability of the called terminal) sent from the facsimile machine on the receiving side. To analyze.

In step S43, the V.V. 29, V.I. 33
Then, the transmission mode and the transmission speed are transmitted to the facsimile machine on the called side by a digital command signal (DCS: a command signal for setting the receiving capability of the called terminal) to set the transmission mode.

In step S44, a training signal is transmitted to test whether transmission is possible in this mode. In step S45, the training result is checked. If the training result is good, the process proceeds to message transmission in step S46, but if it is poor, the mode setting in step S43 is performed again. This procedure is known as fallback. In step S46, message transmission is performed, and when the delivery of the message is confirmed in step S47, the line is disconnected in step S48.

[0010]

In a facsimile having a plurality of modems having different capabilities as described above,
If a modem is selected once before starting communication, that modem will be used until the communication ends. Therefore, for example, in the case of a facsimile machine having a high-capacity modem and a low-capacity modem, there are the following problems. (1) When communication is started with a high-capacity modem and the partner device is a low-capacity modem, communication is performed in the low-capacity mode according to the capabilities of the partner. When another communication is activated during the communication, even if the other party is a high-capacity modem, the remaining low-capacity modem communicates in the low-capacity mode. Therefore, both communications will be performed in the low-capacity mode. (2) When communication is started by a high-capacity modem and the line condition is poor, the transmission speed may fall back to the same as the low-capacity mode. When another communication is activated during the communication, even if the other party is a high-capacity modem, the remaining low-capacity modem communicates in the low-capacity mode. Therefore, both of the communications are performed in the low capacity mode or at the same transmission rate. An object of the present invention is to solve the above-mentioned problems of the prior art, to effectively utilize a high-performance modem, and to obtain a modem selection method that further enhances the transmission efficiency of a communication device.

[0011]

FIG. 1 is a block diagram showing the outline of the present invention. In the figure, modems 100 and 2
00 have different capacities, and are connected to the line via the switching means 300. Further, the modem is an analyzing unit 400 in the communication control unit for analyzing the capability of the modem of the partner device.
Further, the analysis unit 400 is connected to the modem based on the analysis result from the analysis unit.
It is connected to a selection means 500 for selecting a modem suitable for the capability of the partner modem. The selection means 500 is the switching means 3
00 to switch the line between the modem and the line.

As described above, according to the present invention, in the modem selection system of the communication device having the plurality of modems having different capabilities and the means for switching and connecting the modem and the line, the analysis for analyzing the capability of the modem of the partner device is performed. Means, and based on the analysis result from the analysis means, from among the plurality of modems,
It is characterized in that selection means is provided for selecting a modem suitable for the capability of the partner modem.

[0013]

By such means, the modem can be used efficiently and the transmission efficiency of the communication device can be further enhanced.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 2 is a block diagram of a facsimile apparatus to which the present invention is applied. The system control unit 1 controls the entire facsimile apparatus and also controls the modem selection. The scanner 2 is for reading a transmission document, and the panel 3 is a circuit for inputting a telephone number and various instructions and displaying the number, the state of the apparatus, and the like.

The memory 4 is for storing document information read by the scanner 2 and messages received from the line, and also stores programs and various data. The printer 5 is for printing the received message.

Each of the plurality of communication control units 6 has a built-in control device for executing a facsimile transmission control procedure, controls a connected modem, and can perform message transmission / reception independently of other circuits. it can. In addition, by the digital identification signal (DIS: indicating the receiving capability of the called terminal) sent from the facsimile machine on the receiving side,
It also analyzes the capability of the counterpart modem, that is, the transmission mode, and notifies the system control unit.

Under the control of the system controller 1, the first switch 7 includes an optional communication controller 6 and an optional modem 8,
9, and switches such as a crossbar switch and a time division bus type switch can be used.
If all the internal data of the communication control unit 6 is exchanged at the time of switching the modem, the first switch can be omitted and the modem and the communication control unit 6 can be fixedly connected.

The first modem 8 is, for example, a V.V. It is a modem that can transmit in 17 modes. The second modem 9 is, for example, V.V.
It is a modem capable of transmitting in 29 modes. The second switch 10 connects the arbitrary modems 8 and 9 and the arbitrary line control unit (NCU) 11 under the control of the system control unit 1, and the same switch as the first switch can be used. .

A plurality of line control units (NCU) 11 are controlled by the system control unit 1 to control incoming and outgoing lines. The bus 12 connects each circuit in the device. The communication control unit 6, the modems 8 and 9, and the line control unit (NCU) 11 are usually provided in the same number as the number of lines, but a backup device may be provided. FIG. 3 shows an example of three lines.

FIG. 3 is a flow chart showing an outline of the transmission operation of the facsimile having a plurality of modems according to the embodiment of the present invention.

A description will be given below with reference to the drawings. First, the user performs a transmission operation in the facsimile machine. Then,
In step S1, the facsimile control unit 1 selects the modem with the highest transmission capacity from the modems that are not currently used. This is the same as the conventional one. The call origination in step S2 and the capability confirmation of the partner modem in step S3 are the same as in the conventional case.

In step S4, as will be described in detail later, the facsimile controller 1 determines the capability of the partner modem,
Compare the capabilities of the currently selected and in-use modems, and if the capabilities of the other modem are lower, select the lowest available modem that is not less than the capabilities of the other modem. Look for it, select it if you find one, and switch to your current modem.

Alternatively, in the case of fallback, a free modem having the lowest transmission speed with a fallback transmission speed is searched for, and if found, it is selected and switched to the currently used modem. . The subsequent steps S5 to S10 are the same as the conventional one. In step S5, V.V. 29, V.I. A transmission mode such as 33 is determined, and the transmission mode and the transmission speed are sent to the facsimile apparatus on the called side by a digital command signal (DCS: a command signal for setting the receiving capability of the called terminal) to set the transmission mode.

In step S6, a training signal is sent to test whether transmission is possible in this mode.
In step S7, the training result is checked. If the training result is good, the process proceeds to step S8 for message transmission. In step S8, message transmission is performed, and when the delivery of the message is confirmed in step S9, the line is disconnected in step S10.

By adopting such a modem selection system, it becomes possible to effectively utilize the high-performance modem.

FIG. 4 is required for the modem selection processing of the present invention.
It is explanatory drawing which shows an example of a modem capability ranking table and a mounted modem ranking table. (A) The modem capability ranking table is (1) maximum transmission rate (2) capability ranking (determined based on the maximum transmission rate, for a combination of transmission modes possessed by the modems; the smaller the value, the higher the ranking. .) Is stored, and is usually fixed unless a maintenance person or the like performs an external modification process.

The mounted modem order table in (b) is a combination of the transmission mode of the modem with (1) the modem number indicating the mounting position of the modem. (2) Priority used when selecting a modem at the start of communication. (Usually, in descending order of capability rank, if capability ranks are the same, for example, in order of modem number) (3) Capability ranking determined based on the modem capability ranking table. (4) Empty (0), in use (1), faulty, not mounted (-1)
Modem status such as. The registration of the modem is performed at the time of shipment or when the modem is additionally mounted, and the “state” in the table is changed at any time during use.

The priority order (2) among the modems having the same capability order may be replaced every time they are selected, so that they can be selected evenly. These tables are stored in the memory 4 and are retained even when the power is turned off.

Next, the operation of the above embodiment will be described. Incidentally, the state of the mounted modem order table of the own machine is as shown in FIG. 27ter and V.I. The case of having 29 modes will also be described.

FIG. 5 is a detailed flowchart of step S1 of FIG. 3, that is, the modem selection process. First,
In step S11, when there is a transmission request from the facsimile apparatus, the system control unit 1 refers to the mounted modem order table in the memory 4 of FIG. 4B and selects the highest priority order item.

In step S12, it is checked whether the status column of the mounted modem order table is "0" (not currently used). If it is not "0", the process proceeds to step S13, the next highest priority column is selected, and the process returns to step S12.

If the state column of the mounted modem order table is "0" in step S12, the state column of the modem is changed to 1 (in use) in step S14, and the communication control which is still available. Unit 6, line control unit (N
CU) 11 is selected and they are connected by the first switch 7 and the second switch 10. Therefore, for example, in FIG. 4B, the modem with the modem number 1 is selected.

Next, the modem switching process will be described. FIG. 6 is a detailed flowchart of step S4 in FIG. 3, that is, the modem switching process.

First, in step S20, the transmission mode of the partner modem received in step S3 of FIG. 3 is compared with the modem capability column of the modem capability ranking table, and the capability ranking is obtained from the matching column (this 3 in the example
Will be). Then, it is compared with the capability ranking of the modem selected in the modem selection processing of FIG. 5 (obtained from the mounted modem ranking table, 1 in this example).

In step S21, if the rank of the partner modem is higher than the rank of the modem being used by itself, then the modem switching is not performed and the process ends. This is because, in the selection process of the modem of FIG. 5, the one having the highest capability rank of its own device has already been selected, so that it is not possible to switch even if the partner modem has a higher capability rank.

In step S21, if the rank of the partner modem is lower than the rank of the modem being used by itself, in step S22, among the available modems from the mounted modem rank table, Select the one with the next highest capability ranking of the modem currently in use. In this example,
Since the rank 3 of the partner modem is lower than the rank 1 of the modem being used by itself, the modem with the modem number 3 is selected in FIG. 4B.

If there is no modem having a lower performance ranking than the currently selected modem, then as a dummy,
If a device having a rank lower than the existing capability rank is selected, the currently selected modem will be selected later (step S27). To this end, dummy modem data having a rank lower than the existing capability rank, such as the modem number 4, may be provided in the mounted modem rank table of FIG. 4B.

In step S23, step S2
The capability rank 3 of the partner modem obtained in 0 and step S22
Comparing with the capability rank of the modem selected in step (obtained from the mounted modem rank table, 3 in this example). Step S
In step 24, the rank order of capabilities of the partner modem is higher than that of step S2.
If it is higher than the capability rank of the own modem selected in step 2, the process proceeds to step S27. If not, step S
Move to 25.

In step S25, if the capability rank of the partner modem is the same as the capability rank of the own modem selected in step S22, the process proceeds to step S26, and if not, the process returns to step S22 to further capability. Select a lower-ranking modem. In the case of this example, since the capability rank 3 of the partner modem and the capability rank 3 of the modem selected in step S22 are equal, the process proceeds to step S26.

In step S26, the currently used modem and the selected modem are switched by the first switch 7 and the second switch 10, and the status column of the mounted modem order table is rewritten.

In step S24, if the capability rank of the partner modem is higher than the capability rank of the own modem selected in step S22, the process proceeds to step S27.
In step S27, the previously selected modem is reselected.

In step S28, step S2
It is checked whether or not the modem reselected in 7 is the first used modem, and if it is the first used modem, the process is terminated as it is. However, if the reselected modem is not the first used modem, the process proceeds to step S26 to switch the modem.

By the above processing, in this embodiment, communication is initially started with a high-capacity modem, but the capacity of the partner modem is analyzed, and communication is performed by switching to a low-capacity modem. Higher modems can be used for other communications. It should be noted that it is also possible to configure so that a modem having a low capability is selected in step S1 of FIG. 3 at the time of starting communication and a modem having a low capability is selected in step S4, the switching process of the modem. It is possible.

Next, another embodiment will be described. In the embodiment described so far, immediately after checking the capability of the other modem,
Although the modem was switched, the one described next is to switch the modem when the transmission rate falls back due to a bad line condition or the like.

FIG. 7 is a detailed flowchart of the switching process of the modem at the time of fallback in step S4 in FIG. Here, as an example, a case will be described in which communication is started by the modem with the modem number 1 in FIG. 4B, fallback is performed, and the speed is downshifted to 9.6 kbps.

In fallback, the transmission control unit 6 notifies the system control unit 1 of the downshifted transmission rate. In step S30, the system control unit 1 compares this transmission speed with the value in the speed column of the modem capability rank table, and selects the one with the lowest capability rank among the modems having a speed not lower than the downshifted transmission speed. select. Then, the capability ranking is compared with the capability ranking of the modem in use. In this example, the ability ranking is 4.

In step S31, if the capability rank obtained from the transmission speed is not lower than the capability rank of the modem in use, the modem switching process is terminated, and if not, the process proceeds to step S32. The following process
The process is the same as the process from step S22 to step S28 in the first embodiment except that the capability rank obtained from the downshifted speed is used instead of the capability rank of the partner modem.

In step S32, from among the installed modem order tables, the one having the next highest capability order is selected from the available modems next to the currently used modem. In this example, the capability rank 4 obtained from the downshifted speed is lower than the rank 1 of the modem being used by the own device, so that FIG.
In (b), the modem with the modem number 3 is selected. If there is no modem having a lower rank than the currently selected modem, as in the first embodiment,
Select a dummy that has a lower rank than the actual rank of abilities.

In step S33, the capability rank 4 obtained from the downshifted speed is compared with the capability rank of the modem selected in step S32 (3 in this example).
In step S34, if the capability rank of the partner modem is higher than the capability rank of the own modem selected in step S32, the process proceeds to step S37, and if not, the process proceeds to step S35.

In step S35, if the capability rank obtained from the downshifted speed is the same as the capability rank of the own modem selected in step S32, step S3
If not, the process returns to step S32 to select a modem with a lower capability rank.

In the case of this example, since the capability rank 4 obtained from the downshifted speed is lower than the capability rank 3 of the modem selected in step S32, the process proceeds to step S32, and the modem with the lower capability rank is selected. I do. But,
Since there is no corresponding modem, a modem having a capacity rank of 7 is selected as a dummy, and the capacity rank 4 obtained from the downshifted speed is higher than the capacity rank 7 of the selected modem in step S34, and therefore the process proceeds to step S37. .

In step S37, the previously selected modem is reselected. In the case of this example, the modem with the modem number 3 which was selected before the dummy modem is reselected.

In step S38, step S3
It is checked whether or not the modem reselected in 7 is the modem that was used at the beginning, and if it is the modem that was used from the beginning, the process is terminated. However, if the re-selected modem is not the initially used modem, the process proceeds to step S36 to switch the modem. In this example, the first one used is the modem with the modem number 1 and is different from the selected modem with the modem number 3, so the process proceeds to step S36.

In step S36, the currently used modem and the selected modem are switched by the first switch 7 and the second switch 10, and the status column of the mounted modem order table is rewritten.

According to the above processing, in this embodiment, communication with a modem having high capability is started at first, but by fallback, communication can be performed by switching to a modem with low capability, and transmission of this communication. A high-performance modem can be used for other communication without changing the speed.

Some models having an error correction mode may fall back even when a message is retransmitted, but the selection method of this embodiment can of course be applied to that case.

Although two embodiments have been described above, these two selection methods may be applied to one facsimile machine.

When selecting a modem, a modem having the same transmission mode as that of the partner modem must be selected. Generally, a modem having a higher capability mode also has a lower capability mode. In most cases, you can select only by ability ranking. However, in the case of a modem that does not have a lower mode, it may not be possible to communicate with a modem with a lower capability rank even if the capability rank is higher. In such a case, the capability rank and mode are set. It is necessary to select them together.

Although the facsimile apparatus has been described as the embodiment, the present invention can be applied to a general communication apparatus having a plurality of modems having different capabilities.

[0060]

According to the modem selection system of the present invention, there is an effect that the modem can be used efficiently and the transmission efficiency of the communication device can be further enhanced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of the present invention.

FIG. 2 is a block diagram of a facsimile apparatus to which the present invention is applied.

FIG. 3 is a flowchart showing an outline of a transmission operation of a facsimile having a plurality of modems.

FIG. 4 is an explanatory diagram showing an example of a modem capability rank table and a mounted modem rank table necessary for a modem selection process.

5 is a detailed flowchart of a modem selection process in FIG. 1. FIG.

FIG. 6 is a detailed flowchart of a modem switching process according to the present invention.

FIG. 7 is a detailed flowchart of a modem switching process at the time of fallback according to the present invention.

FIG. 8 is a flowchart showing an outline of a transmission operation of a conventional facsimile which can accommodate a plurality of lines.

[Explanation of symbols]

1 ... System control unit, 2 ... Scanner, 3 ... Panel, 4 ...
Memory, 5 ... Printer, 6 ... Communication control unit, 7 ... First switch, 8 ... First modem, 9 ... Second modem, 10 ...
Second switch, 11 ... Network control unit (NCU), 12 ...
bus,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Kinami 3-7-1 Fuchu, Iwatsuki City, Saitama Fuji Xerox Co., Ltd. Iwatsuki Office

Claims (1)

[Claims] 1. An analyzing unit for analyzing the capability of a modem of a partner device in a modem selection system of a communication device, comprising: a plurality of modems having different capabilities; and a unit for switching and connecting the modem and a line, and the analyzing unit. A modem selection system characterized in that selection means is provided for selecting a modem suitable for the capability of the partner modem from among the plurality of modems based on the analysis result from.