Automatically controlling the operation mode of data circuit terminating equipment in a communication system

• US 5,153,897 A
• Filed: 07/10/1990
• Issued: 10/06/1992
• Est. Priority Date: 09/27/1988
• Status: Expired due to Fees

• Current Assignee: NTT Data Communications Systems Corporation, Texas Instruments Japan Limited (Texas Instruments, Inc.), Ohkura Electric Co., Ltd. (Y.A.C. Holdings Co., Ltd.)
• Original Assignee: NTT Data Communications Systems Corporation, Texas Instruments Japan Limited (Texas Instruments, Inc.), Ohkura Electric Co., Ltd. (Y.A.C. Holdings Co., Ltd.)
• Inventors: Abe, Kenichi, Sumiyoshi, Kikuo, Kurashina, Kenji, Kaji, Kenzou, Kaneuchi, Masumi
• Primary Examiner(s): Safourek, Benedict V.
• Application Number:
  US07/476,450
• Time in Patent Office: 819 Days
• Field of Search: 375/8, 375/9, 375/121, 370/24, 370/31, 379/93, 379/97, 379/98, 379/102, 379/105
• US Class Current: 375/222
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors

Abstract

The operation modes of a plurality of modems in a communication system are matched with each other for connection of digital terminals to an analog telephone line on both the calling and answering sides of the analog telephone line. For example, operation modes of modems on both sides of the analog telephone line can automatically be matched with each other by transferring a mode instructing signal with DTMF, using multi-frequency DTMF symbols for a select signal employed in the telephone line, between digital terminals connected to both ends of the telephone line. More specifically, even in the case of the calling and answering sides being in different initial operation modes, the different operation modes are matched by setting a desired operation mode on the calling side and generating an off-hook signal on the answering side in response to a calling signal, followed by (1) transmitting an operation mode instructing signal in the form of a code with DTMF from the calling side to the answering side, setting the instructed operation mode on the answering side and returning if it can be set on that side, and then returning an answer tone to the calling side for completing the mode matching; or when the operation mode instructed from the calling side cannot be set on the answering side, transmitting an operable mode in the form of a code with DTMF from the answering side to the calling side, and transmitting again the code corresponding to that mode from the calling side to the answering side if that mode can be set on the calling side, thereby matching operation modes of both the calling and answering sides, or (2) transmitting an operation mode instructing signal in the form of a code with DTMF from the answering side to the calling side, and then carrying out a procedure similar to above (1).

Claims

1. A method for controlling a communications system by matching an operation mode of a first data circuit terminating equipment ("DCE") with an operation mode of at least a second DCE, said communications system including a first terminal coupled to a communications netwoork via said first DCE, and a second terminal coupled to said communications network via said second DCE, said first and second terminals respectively communicating with said first and second DCE'"'"'s in a synchronous mode, wherein said method comprises the steps of:

storing an initial operation mode of said second DCE in a memory of said first terminal;

sending from the first terminal to the first DCE an operation mode setting command corresponding to said initial operation mode before said first terminal issues to or receives from the communications network a call via said first DCE;

analyzing with the gfirst DCE said operation mode setting command; and

controlling said first DCE to have an operation mode which matches said initial operation mode of said second DCE in response to a result of said analyzing step.

2. A method for controlling a communications system by matching an operation mode a first modem with an operation mode of at least a second modem, said communications system including a first terminal coupled to an analog telephone line via said first modem, and a second terminal coupled to said analog telephone line via said second modem, said first and second modems respectively communicating with said first and second terminals in a synchronous mode, wherein said method comprises the steps of:

storing an initial operation mode of said second modem in a memory of said first terminal;

sending from the first terminal to the first modem an operation mode setting command corresponding to said inital operation mode before said first terminal issues to or receives from the analog telephone line a call via said first modem;

analyzing with the first modem said operation mode setting command; and

controlling said first modem to have an operation mode which matches said initial operation mode of said second modem in response to a result of said analyzing step.

3. A method for controlling a communications system by matching an operation mode of a first circuit terminating equipment ("DCE") with an operation mode of at least a second DCE, said communications system including a first terminal equipment ("DTE") coupled to a communications network via said first DCE, and second DTE coupled to said communications network via said second DCE, wherein said method comprises the steps of:

providing said first DCE with a first set of selected operation modes, and providing said second DCE with a second set of selected operation modes such that said first and second DCE'"'"'s can be set to operate in any one said first and second sets of selected operation modes, respectively;

storing operation mode command signals in said first DTE corresponding to said first set of selected operation modes, and storing in said second DTE operation mode command signals corresponding to said second set of selected operation modes;

transmitting from said first DTE to said first DCE one of said operation mode command signals corresponding to said first set of selected operation modes in accordance with a start-up operation triggered by said first DTE;

following receipt by the second DCE of a ringing tone signal, transmitting said one operation mode command signal from said first DCE to said second DCE after a connection has been completed therebetween via said communications network;

if said one operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second DCE to the operation mode corresponding to said one operation mode command signal;

transmitting an answer signal from the second DCE to the first DCE; and

transmitting a transmission/receipt ready signal from the first and second DCE'"'"'s respectively, the first and second DTE'"'"'s after said match has occurred.

4. The method for controlling a comminications system of claim 3, further comprising the steps of:

if said one operation mode command signal does not correspond to an operation mode included in the second set of selected operation modes, transmitting from said second DCE to said first DCE another operation mode command signal which corresponds to an operation mode in the second set of selected operation modes;

if said other operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first DCE to the operation mode corresponding to said other operation mode command signal;

transmitting said other operation mode command signal from the first DCE to said second DCE;

setting an operation mode of said second DCE to the peration mode corresponding to other operation mode signal received from said first DCE;

transmitting said answer signal from the second DCE to the first DCE; and

transmitting said transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

5. A method for controlling a communications system by matching an operation mode of a first modem with an operation mode of at least a second modem, said communications system including a first terminal coupled to an analog telephone line via said first modem, and a second terminal coupled to said analog telephone line via said second modem, wherein said method comprises the steps of:

providing said first modem with a first set of selected operation modes, and providing said second modem with a second set of selected operation modes such that said first and second modems can be set to operate in any one of said first and second sets of selected operation modes, respectively;

storing operation mode command signals in said first terminal corresponding to said first set of selected operation modes, and storing in said second terminal operation mode command signals corresponding to said second set of selected operation modes, said operation mode command signals being comprised of combined codes composed of mulyi-frequency DTMF codes;

transmitting from said first terminal to said first modem one of said operation mode command signals corresponding to said first set of selected operation modes in accordance with a start-up operation triggered by said first terminal;

following receipt by the second modem of a ringing tone signal, transmitting said one operation mode command signal from said first modem to said second modem after a connection has been completed therebetween via analog telephone line;

if said one operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second modem to the operation mode corresponding to said one operation mode command signal;

transmitting an answer signal from the second modem to the first modem; and

transmitting a transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

6. The method for controlling a communications system of claim 5, further comprising the steps of:

if said one operation mode command signal does not correspond to an operation mode included in the second set of selected operation modes, transmitting from said second modem to said first modem another operation mode command signal which corresponds to an operation mode included in the second set of selected operation modes;

if said other operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first modem to the operation mode corresponding to said other operation mode command signal;

transmitting said other operation mode command signal from the first modem to said second modem;

setting an operation mode of said second modem to the operation mode correspnding to said other operation mode signal received from said first modem;

transmitting said answer signal from the second modem to the first modem; and

transmitting said transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

7. A method for controlling a communications system by matching an operation mode of a first data circuit terminating equipment ("DCE") with an operation mode at least a second DCE, said communications system including a first terminal equipment ("DTE") coupled to a communications network via said first DCE, and a second DTE coupled to said communications network via said second DCE, wherein said method comprises the steps off:

providing said first DCE with a first set of selected operation modes, and providing said second DCE with a second set of selected operation modes such that said first and second DCE'"'"'s can be set to operate in any one of said first and second sets of selected operation modes, respectively;

storing operation mode command signals in said first DTE corresponding to said first set of selected operation modes, and storing in said second DTE operation mode command signals corresponding to said second set of selected operation modes;

transmitting from said second DTE to said second DCE one of said operation mode command signals corresponding to said first set of selected operation modes in accordance with a start-up operation triggered by said second DTE;

following receipt by the second DCE of a ringing tone signal, transmitting said one operation mode command signal from said second DCE to said first DCE after a connection has been completed therebetween via said said communications network;

if said one operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first DCE to the operation mode corresponding said one operation mode command signal;

transmitting an answer signal from the second DCE to the first DCE; and

transmitting a transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

8. The method for controlling a communications system of claim 7, further comprising the steps of:

if said one operation mode command signal does not correspond to an operation mode included in the first set of selected operation modes, transmitting from said first DCE to said second DCE another operation mode command signal which corresponds to an operation mode included in the first set of selected operation modes;

if said other operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second DCE to the operation mode corresponding to said other operation mode command signal;

transmitting said other operation mode command signal from the second DCE to said first DCE;

setting an operation mode of said first DCE to the operation mode corresponding said other operation mode signal received from said second DCE;

transmitting said answer signal from the second DCE to the first DCE; and

transmitting said transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

9. A method for controlling a communications system by matching an operation mode of a first modem with an operation mode of at least a second modem, said communications system including a first terminal coupled to an analog telephone line via said first modem, and a second terminal coupled to said analog telephone line via said second modem, wherein said method comprises the steps of:

providing said first modem with a first set of selected operation modes, and providing said second modem with a second set of selected operation modes such that said first and second modems can be set to operate in any one of said first and second sets of selected operation modes, respectively;

storing operation mode command signals in said first terminal corresponding to said first set of selected operation modes, and storing in said second terminal operation mode command signals corresponding to said second set of selected operation modes;

transmitting from said second terminal to said second modem one of said operation mode command signals corresponding to said second set of selected operation modes in accordance with a start-up operation triggered by said second terminal;

following receipt by the second modem of a ringing tone signal, transmitting said one operation mode command signal from said second modem to said first modem after a connection has been completed therebetween via said analog telephone line;

if said one operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first modem to the operation mode corresponding to said one operation mode command signal;

transmitting an answer signal from the second modem to the first modem; and

transmitting a transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

10. The method for controlling a communications system of claim 9, further comprising the steps of:

if said one operation mode command signal does not correspond to an operation mode included in the first set of selected operation modes, transmitting from said first modem to said second modem another operation mode command signal which corresponds to an operation mode included in the first set of selected operation modes;

if said other operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second modem to the operation mode corresponding to said other operation mode command signal;

transmitting said other operation mode command signal from the second modem to said first modem;

setting an operation mode of said first modem to the operation mode corresponding to said other operation mode signal received from said second modem;

transmitting said answer signal from the second modem to the first modem; and

transmitting said transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

11. A communications system, comprising:

a first terminal coupled to a communications network via a first data circuit terminating equipment ("DCE");

a second terminal coupled to said communications network via a second DCE;

means to control said first and second terminals for respectively communicating with said first and second DCE'"'"'s in a synchronous mode;

wherein said first terminal comprises

means for storing an initial operation mode of said second DCE; and

means for sending from the first terminal to the first DCE an operation mode setting command corresponding to said initial operation mode before said first terminal issues to or receives from the communications network a call via said first DCE; and

wherein said first DCE includes

means for analyzing said operation mode setting command; and

means for controlling said first DCE to have an operation mode which matches said initial operation mode of said second DCE in response to an output of said analyzing means.

12. A communications system, comprising:

a first terminal coupled to an analog telephone line via a first modem;

a second terminal coupled to said analog telephone line via a second modem;

means to control said first and second modems for respectively communicating with said first and second terminals in a synchronous mode;

wherein said first terminal includes

means for storing an initial operation mode of said second modem; and

means for sending from the first terminal to the first modem an operation mode setting command corresponding to said initial operation mode before said first terminal issues to or receives from the analog telephone line a call via said first modem; and

wherein said first modem includes

means for analyzing said operation mode setting command; and

means for controlling said first modem to have an operation mode which matches said initial operation mode of said second modem in response to an output of said analyzing means.

13. A communications system, comprising:

a first terminal equipment ("DTE") coupled to a communications network via a first data circuit terminating equipment ("DCE");

a second DTE coupled to said communications network via a second DCE;

means for providing said first DCE with a first set of selected operation modes, and for providing said second DCE with a second set of selected operation modes such that said first and second DCE'"'"'s can be set to operate in any one of said first and second sets of selected operation modes, respectively;

means for storing operation mode command signals in said first DTE corresponding to said first set of selected operation modes, and means for storing in said second DTE operation mode command signals corresponding to said second set of selected operation modes;

means for transmitting from said first DTE to said first DCE one of said operation mode command signals corresponding to said first set of selected operation modes in accordance with a start-up operation triggered by said first DTE;

means for, following receipt by the second DCE of a ringing tone signal, transmitting said one operation mode command signal from said first DCE to said second DCE after a connection has been completed therebetween via said communications network;

means for, if said one operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second DCE to the operation mode corresponding to said one operation mode command signal;

means for transmitting an answer signal from the second DCE to the first DCE; and

means for transmitting a transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

14. The communications system of claim 13, further comprising:

means for, if said one operation mode command signal does not correspond to an operation mode included in the second set of selected operation modes, transmitting from said second DCE to said first DCE another operation mode command signal which corresponds to an operation mode included in the second set of selected operation modes;

means for, if said other operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first DCE to the operation mode corresponding to said other operation mode command signal;

means for transmitting said other operation mode command signal from the first DCE to said second DCE;

means for setting an operation mode of said second DCE to the operation mode corresponding to said other operation mode signal received from said first DCE;

means for transmitting said answer signal from the second DCE to the first DCE; and

means for transmitting said transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

15. A communications system, comprising:

a first terminal coupled to an analog telephone line via a first modem;

a second terminal coupled to said analog telephone line via a second modem;

means for providing said first modem with a first set of selected operation modes, and for providing said second modem with a second set of selected operation modes such that said first and second modems can be set to operate in any one of said first and second sets of selected operation modes, respectively;

means for storing operation mode command signals in said first terminal corresponding to said first set of selected operation modes, and means for storing in said second terminal operation mode command signals corresponding to said second set of selected operation modes, said operation mode command signals being comprised of combined codes composed of multi-frequency DTMF codes;

means for transmitting from said first terminal to said first modem one of said operation mode command signals corresponding to said first set of selected operation modes in accordance with a start-up operation triggered by said first terminal;

means for, following receipt by the second modem of a ringing tone signal, transmitting said one operation mode command signal from said first modem to said second modem after a connection has been completed therebetween via said analog telephone line;

means for, if said one operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second modem to the operation mode corresponding to said one operation mode command signal;

means for transmitting an answer signal from the second modem to the first modem; and

means for transmitting a transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

16. The communications system of claim 15, further comprising:

means for, if said one operation mode command signal does not correspond to an operation mode included in the second set of selected operation modes, transmitting from said second modem to said first modem another operation mode command signal which corresponds to an operation mode included in the second set of selected operation modes;

means for, if said other operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first modem to the operation mode corresponding to said other operation mode command signal;

means for transmitting said other operation mode command signal from the first modem to said second modem;

means for setting an operation mode of said second modem to the operation mode corresponding to said other operation mode signal received from said first modem;

means for transmitting said answer signal from the second modem to the first modem; and

means for transmitting said transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

17. A communications system, comprising:

a first terminal equipment ("DTE") coupled to a communications network via a first data circuit terminating equipment ("DCE");

a second DTE coupled to said communications network via a second DCE;

means for providing said first DCE with a first set of selected operation modes, and for providing said second DCE with a second set of selected operation modes such that said first and second DCE'"'"'s can be set to operate in any one of said first and second sets of selected operation modes, respectively;

means for storing operation mode command signals in said first DTE corresponding to said first set of selected operation modes, and for means for storing in said second DTE operation mode command signals corresponding to said second set of selected operation modes;

means for transmitting from said second DTE to said second DCE one of said operation mode command signals corresponding to said first set of selected operation modes in accordance with a start-up operation triggered by said second DTE;

means for, following receipt by the second DCE of a ringing tone signal, transmitting said one operation mode command signal from said second DCE to said first DCE after a connection has been completed therebetween via said communications network;

means for, if said one operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first DCE to the operation mode corresponding to said one operation mode command signal;

means for transmitting an answer signal from the second DCE to the first DCE; and

means for transmitting a transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

18. The communications system of claim 17, further comprising:

means for, if said one operation mode command signal does not correspond to an operation mode included in the first set of selected operation modes, transmitting from said first DCE to said second DCE another operation mode command signal which corresponds to an operation mode included in the first set of selected operation modes;

means for, if said other operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second DCE to the operation mode corresponding to said other operation mode command signal;

means for transmitting said other operation mode command signal from the second DCE to said first DCE;

means for setting an operation mode of said first DCE to the operation mode corresponding to said other operation mode signal received from said second DCE;

means for transmitting said answer signal from the second DCE to the first DCE; and

means for transmitting said transmission/receipt ready signal from the first and second DCE'"'"'s to, respectively, the first and second DTE'"'"'s after said match has occurred.

19. A communications system, comprising:

a first terminal coupled to an analog telephone line via a first modem;

a second terminal coupled to said analog telephone line via a second modem;

means for providing said first modem with a first set of selected operation modes, and for providing said second modem with a second set of selected operation modes such that said first and second modems can be set to operate in any one of said first and second sets of selected operation modes, respectively;

means for storing operation mode command signals in said first terminal corresponding to said first set of selected operation modes, and means for storing in said second terminal operation mode command signals corresponding to said second set of selected operation modes;

means for transmitting from said second terminal to said second modem one of said operation mode command signals corresponding to said second set of selected operation modes in accordance with a start-up operation triggered by said second terminal;

means for, following receipt by the second modem of a ringing tone signal, transmitting said one operation mode command signal from said second modem to said first modem after a connection has been completed therebetween via said analog telephone line;

means for, if said one operation mode command signal corresponds to an operation mode included in the first set of selected operation modes, setting an operation mode of said first modem to the operation mode corresponding to said one operation mode command signal;

means for transmitting an answer signal from the second modem to the first modem; and

means for transmitting a transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.

20. The communications system of claim 19, further comprising:

means for, if said one operation mode command signal does not correspond to an operation mode included in the first set of selected operation modes, transmitting from said first modem to said second modem another operation mode command signal which correspond to an operation mode included in the first set of selected operation modes;

means for, if said other operation mode command signal corresponds to an operation mode included in the second set of selected operation modes, setting an operation mode of said second modem to the operation mode corresponding to said other operation mode command signal;

means for transmitting said other operation mode command signal from the second modem to said first modem;

means for setting an operation mode of said first modem to the operation mode corresponding to said other operation mode signal received from said second modem;

means for transmitting said answer signal from the second modem to the first modem; and

means for transmitting said transmission/receipt ready signal from the first and second modems to, respectively, the first and second terminals after said match has occurred.