Apparatus and method for conveying TTY signals over wireless telecommunication systems

• US 6,351,495 B1
• Filed: 08/28/1998
• Issued: 02/26/2002
• Est. Priority Date: 08/28/1998
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Tarraf, Ahmed A.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Tran, Khai
• Application Number:
  US09/143,416
• Time in Patent Office: 1,278 Days
• Field of Search: 375/259, 375/219, 379/52, 379/88, 379/93.17, 379/93.18, 320/342, 704/221, 455/553, 455/556, 455/557
• US Class Current: 375/259
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04M 11/066 Telephone sets adapted for data transmision

Abstract

An apparatus and method for conveying teletype signals over a wireless telecommunication system. When the apparatus receives a teletype signal, it derives information carried by said signal and represents said information as at least one message. The at least one message and/or the teletype signal is transmitted over the wireless telecommunication system. When the apparatus receives a signal from the wireless telecommunication system that it determines to be a teletype signal, the apparatus of the present invention decodes the teletype information from part of the received signal determined as not having been adversely affected by the telecommunication system.

Claims

1. A teletype signal processor for teletype signals comprising one or more teletype information bits and one or more teletype start or stop bits over a wireless telecommunication system, the teletype signal processor comprising:

a transmitter configured to derive the teletype information bits from the teletype signals, represent the derived teletype information bits as at least one message in accordance with a format, and transmit said at least one message over the wireless telecommunication system or transmit said at least one message and the teletype signals over the wireless telecommunication system; and

a receiver configured to receive signals from the wireless telecommunication system, determine whether such received signals are teletype signals carrying teletype information in accordance with the format, and decode the teletype information from part of the received signals determined as not having been adversely affected by the wireless telecommunication system.

2. The teletype signal processor of claim 1 wherein the transmitter comprises a RX Teletype Interface Unit coupled to a Message Generator which is coupled to a Formatting Unit where the RX Teletype Interface Unit is configured to receive analog signals, determine whether the received signals are teletype signals, derive the teletype information bits from the teletype signals, and transfer the derived teletype information bits to the Message Generator.

3. The teletype signal processor of claim 1 wherein the receiver comprises an Information Processing Unit coupled to a Decoding Unit which is coupled to a TX Teletype Interface Unit where the Information Processing unit is configured to receive signals from the wireless telecommunication system, determine whether such signals are teletype signals, arrange the received signals in accordance with a format being followed by the wireless telecommunication system, and transfer the arranged received signals to the Decoding Unit.

4. The teletype signal processor of claim 2 wherein the Message Generator is configured to generate at least one message in accordance with a message format that represents the teletype information bits derived from the teletype signals and transfer the at least one message and the received signals to the Formatting Unit.

5. The teletype signal processor of claim 4 wherein the Formatting Unit is configured to arrange the teletype signals and the at least one message in accordance with a format being followed by the wireless telecommunication system.

6. The teletype signal processor of claim 3 wherein the Decoding Unit is configured to perform an analysis of the arranged received signals received from the Information Processing Unit, decode the teletype information from the part of the received signals determined as not having been adversely affected by the wireless telecommunication system, and transfer the decoded teletype information to the TX teletype interface unit.

7. The teletype signal processor of claim 6 wherein the TX teletype interface unit converts the decoded teletype information received from the Decoding Unit to a teletype signal.

8. A method for conveying teletype signals comprising one or more teletype information bits and one or more teletype start or stop bits over a wireless telecommunication system, the method comprising the steps of:

receiving a first signal;

deriving one or more teletype information bits from the received first signal, representing said one or more teletype information bits as at least one message in accordance with a format, and transmitting said at least one message with or without the received first signal over the wireless telecommunication system when it is determined that the received first signal is a teletype signal; and

receiving a second signal from the wireless telecommunication system, decoding teletype information from part of the received second signal determined as not having been adversely affected by the wireless telecommunication system when it has been determined that the received second signal comprises either at least one message representing teletype information or a teletype signal along with at least one message representing teletype information.