Week 2 - Short Answers

Class: NTC 360

Instructor: Stephen Omogbehin

Date: February 5, 2007

Rotary and Dual Tone Multi-frequency (DTMF) - the difference between rotary telephones and dual tone multi-frequency, or DTMF, telephones is in how the person dials the phone and how the phone responds when the dialing occurs. According to Dean (2003), "In rotary dialing, a user chooses a number and turns a wheel from that number to the finger stop (a small metal bar), then releases the wheel" (p. 197). A circuit opens in response to the wheel being moved and, when the user lets go of the wheel, a series of pulses are issued because the circuit alternately opens a closes as the wheel returns to its beginning state. The translation of the pulses into numbers occurs at the local central office's...