Method and system for encoding and decoding typographic characters

• US 6,396,921 B1
• Filed: 11/07/1997
• Issued: 05/28/2002
• Est. Priority Date: 11/07/1997
• Status: Expired due to Fees

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Longster, Gary
• Primary Examiner(s): WOO, STELLA L
• Application Number:
  US08/966,387
• Time in Patent Office: 1,663 Days
• Field of Search: 379/386,93.27,93.26,93.18
• US Class Current: 379/386
• CPC Class Codes: G06F 40/126 Character encoding

Abstract

A system suitable for encoding typographic characters into two digit base ten values and to decode such values to typographic characters are disclosed. The system maps typographic characters, such as letters in the English language and puctuation symbols into two decimal digit numeric codes. The mapped numeric codes allow all upper and lower case English letters to be identified by a unique two digit code, that may be encoded using conventional DTMF tones. The system similarly decodes two digit numeric codes, so encoded. The system optionally include a DTMF generator and decoder. Methods used by the system are also disclosed.

Claims

1. A method of numerically encoding a typographic character using a computing device, comprising the steps of:

a. determining a value of a numeric standard ASCII code representing said character; and

b. for said determined value greater than ninety-nine, mapping said character using said ASCII code to a two decimal digit numeric code having a value between zero and ninety-nine, using a defined mapping so that said numeric code uniquely identifies said character,

c. for said determined value less than or equal to ninety-nine, mapping said ASCII code to a two decimal digit numeric code having a value between zero and ninety-nine, said numeric code having a value different than said ASCII code, using said defined mapping so that said numeric code uniquely identifies said character,

wherein steps b. and c. further comprise subtracting an offset from said determined value to form said numeric code.

2. The method of claim 1, wherein said offset exceeds twenty-two.

3. The method of claim 2, wherein said offset is less than forty-nine.

4. The method of claim 3, wherein said offset equals thirty-two.

5. A system for encoding a typographic symbol comprising:

a. an input port for receiving a digital representatiol L of a numeric standard ASCII code representing said character; and

b. a mapper in communication with said input port, for mapping said ASCII code to a numeric code having a value between zero and ninety-nine, said numeric code uniquely identifying said character;

c. an output port for outputting a digital representation of said numeric code,

wherein said mapper produces a value different than said ASCII code, for all ASCII codes,

wherein said mapper is adapted to subtract an offset from said ASCII code to form said numeric code.

6. The system of claim 5, wherein said offset exceeds twenty-two.

7. The system of claim 6, wherein said offset equals thirty-two.

8. A method of decoding a two decimal digit numeric code to form a character, comprising:

a. receiving said two decimal digit numeric code;

c. mapping said two decimal digit numeric code to an ASCII code representing said character, using a defined relationship between said numeric code and said ASCII code,

wherein step b. further comprises adding a value of thirty-two to a value of said numeric code to form said ASCII code.