Patent ID: 8605889
Filing Date: 2013-12-10
Classification: H04M

Abstract:
1. A dual-tone generating telecommunication device comprising: a frequency generating element that produces at least 9 individual tones, each having a distinct frequency between 300 Hz and 3,000 Hz; at least 17 dial buttons, with actuation of each dial button causes an encoding of at least one distinct character; and the encoding of each character directs the frequency generating element to produce a distinct dual tone, with each distinct dual tone being generated by the combination of two different individual tones and at least 95 characters are each encoded with a distinct dual tone combination of less than 20 individual tones; the distinct dual tones generated for characters A, B, C, and D are at frequencies of 1633 Hz & 697 Hz; 1633 Hz & 770 Hz; 1633 Hz & 852 Hz; and 1633 Hz & 941 Hz, respectively.