June 2, 1875 is a fateful day in the annals of telephone communication history as this was the day when Alexander Graham Bell while experimenting with his technique called “harmonic telegraph” discovered for the first time he could hear sound over a wire. The initial sound resembled the twanging clock spring. Bell’s greatest success was achieved – in less than a year thereafter – on March 10, 1876 – when telephone system came into existence. Since then, the telephone system has revolutionized the way we socialize and do business.
Graham Bell’s notebook entry of 10 March 1876 reveals his successful experiment with the telephone. Speaking over the telephone instrument to his assistant, Thomas A. Watson, in the adjacent room, Bell spoke those historic first words, “Mr. Watson — come here — I want to see you.”
During the year 1877, the first regular telephone line from Boston to Somerville, Massachusetts was completed. The first regular telephone exchange was established in New Haven in 1878. By the end of 1880, there were 47,900 telephones operating in the United States. The first exchange using the Strowger switch was opened in La Porte, Indiana in 1892. Telephone service between New York and Chicago also became operational in 1892 and between New York and Boston in 1894. Transcontinental service by overhead wire however came into being only in 1915.
In 1889, the first coin-operated telephone – or what we now call payphone – was patented and a payphone was first installed and used in the Hartford Bank. This Boston Limo Car Service was followed in 1941 by the touch-tone system that used tones in the voice frequency range instead of pulses generated by the earlier rotary dials. Then telephony witnessed the giant stride in the 1970s when the very first cordless phones surfaced. In the year 1986, the Federal Communications Commission (FCC) granted the frequency range of 47-49 MHz for cordless phones and increased the frequency range to 900 MHz in 1990.
Four years hence, in 1994 we saw the emergence of digital cordless phones and that was quickly followed by digital spread spectrum (DSS). Both these developments were intended to strengthen the security aspect of cordless phones. In 1998, the FCC granted the frequency range of 2.4 GHz for cordless phones and again in 2003 the upward range became 5.8 gigahertz.
In the year 1947, research into cell phones technology began with an examination of the limited mobile (car) phones. Later on, research scientists realized that by using small cells (range of service area) with frequency reuse, it will be possible to increase the traffic capacity of mobile phones substantially.