Method for controlling data transmission in a wireless v.24 data transmission system operating between a data terminal and a data transmission device for data telecommunication

• US 6,823,396 B1
• Filed: 02/12/2001
• Issued: 11/23/2004
• Est. Priority Date: 08/12/1998
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Biedermann, Rolf, Alfaro, Diego Garcia
• Primary Examiner(s): VU, THONG H
• Application Number:
  US09/762,835
• Time in Patent Office: 1,380 Days
• Field of Search: 709/203, 709/246, 709/201, 709/207, 709/219, 709/228, 709/231, 709/236, 709/400, 709/239, 709/251, 709/233, 709/235, 370/330, 370/493, 370/347, 370/338, 370/349, 370/260, 380/29, 380/247, 705/39, 705/28, 455/517, 455/426, 455/63, 455/436, 375/267, 375/364, 375/149, 375/139, 345/600, 713/500, 708/204, 341/50
• US Class Current: 709/246
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A method for controlling data transmission in a wireless V.24 data transmission system operating between a data terminal and a data transmission device. The data transmission system has a first data transmission apparatus connected to a data terminal by means of a V.24 cable and a second data transmission apparatus also connected to a data transmission device by means of a V.24 cable. An air interface may be used for wireless telecommunications in order to control transmission of control commands or control information for the data transmission device from the data terminal to the data transmission device. Recognizability of control commands or control information for the data transmission device is ensured, once a time-critical control command is made known in the data transmission apparatuses. After transmission has been completed on the transmission path between the first data transmission apparatus and the data terminal, the time sequence of the transmission of the control command on the transmission path between the second data transmission apparatus and the data transmission device is identically reconstructed, despite any asynchronous data transmission caused by the air interface in the wireless V.24 data transmission system.

Claims

1. A method for controlling data transmission in a wireless V.24 data transmission system operating between a data terminal and a data transmission device, the V.24 data transmission system having a first V.24 data transmission apparatus and a second V.24 data transmission apparatus interconnected via an air interface, the first V.24 data transmission apparatus being connected to the data terminal, the second V.24 data transmission apparatus being connected to the data transmission device, the data transmission device being connected to a remote data transmission device having a downstream remote data terminal, the method comprising the steps of:

providing the V.24 data transmission apparatuses with time-critical control information known to the data terminal and to the data transmission device which can be changed by the user of the data terminal, wherein if the control information is unchanged, preconfiguring the control information in the V.24 data transmission apparatuses, or if the control information is changed, determining in at least one of the V.24 data transmission apparatuses the changed control information transmitted in a command data transmission mode of the data terminal, the data transmission device and the V.24 data transmission apparatuses in a command data stream from the data terminal to the data transmission device, and notifying the other V.24 data transmission apparatus of the changed control information;

determining in the first V.24 data transmission apparatus, in a user data transmission mode of the data terminal, the data transmission device and the V.24 data transmission apparatuses, from a user data stream sent from the data terminal to the data transmission device, a first actual pause time of a first transmission pause of the control information which immediately precedes the transmission of a first character of a character set of the control information, and a second actual pause time of a second transmission pause of the control information which immediately follows the transmission of the last character of the character set;

comparing in the first V.24 data transmission apparatus, the first actual pause time with a first nominal pause time and the second actual pause time with a second nominal pause time;

transmitting in the user data transmission mode via signaling, from the first V.24 data transmission apparatus special information to the second V.24 data transmission apparatus, notification of the results of the comparison if the comparison shows that the first actual pause time is greater than or equal to the first nominal pause time or the second actual pause time is greater than or equal to the second nominal pause time; and

transmitting from the second V.24 data transmission apparatus in the user data transmission mode, to the data transmission device the user data stream in which the first transmission pause, having a third actual pause time immediately precedes the transmission of the first character of the character set, and in which the third actual pause time is greater than or equal to the first nominal pause time, wherein the second transmission pause having a fourth actual pause time immediately follows transmission of the last character of a character set in which the fourth actual pause time is greater than or equal to the second nominal pause time.

2. The method of claim 1, wherein an ESCAPE data sequence is formed as a time-critical control command from the control information, with the character set and the transmission pauses have one of actual pause times or nominal pause times, respectively.

3. The method of claim 2, wherein the first actual pause time and the second actual pause time are identical, the third actual pause time and the fourth actual pause time are identical, and the first nominal pause time and the second nominal pause time are identical.

4. The method of claim 3, wherein the command data are Hayes-specific commands having the Hayes prefix “

AT (Attention)”

.

5. The method of claim 4, wherein a modem is used as the data transmission device and a personal computer is used as the data terminal.

6. The method of claim 5, wherein a DECT air interface is used as the air interface.