This handbook was created to provide individuals responsible for managing and implementing Traffic Signal, and Freeway Management programs with an understand of the basic technologies of telecommunications. The handbook provides a brief look at the history of telecommunications so that its readers may gain an understanding of why various processes exist, and how the technologies evolved. The handbook is not designed to be used as a specification for telecommunication systems. The technologies associated with telecommunications are in a constant state of change. This handbook was written over a two year period between August, 2002 and June 2004. During this time, a number of emerging technologies began to reach maturity. The most significant of these, wireless internet access, and voice over IP have caused the major carriers (telephone companies) to announce the construction of new facilities to provide "Internet Telephony" services. Readers of this handbook should gain an understanding of the basic technologies underlying most telecommunications systems designed to transmit both voice and data information.