One of the greatest inventions of mankind is the telephone. Over the years, it has evolved into something that provides utmost convenience to its users. It does not only have the function of transmitting your voice from one end to another but it does that in a clear, wireless way.
How Does It Really Work?
Basically, it functions using what they call a PSTN or a Public Switch Telephone Network. This is a particular network that houses the use of numeric switches that allow signal transmission through fiber optic cables and wires. Fiber optic cables are the most flawless form of transmission and also the fastest which enables it to transmit signal even when there are information traffics.
A typical phone system has a receiver. This receiver can pick up signals. It also has a microphone-that mouthpiece with holes in it, that allows data to be converted. It will pass in the communication pathway to be delivered to the person you are calling. This is much the same process of wireless phones too. Only in wireless, they can utilize a satellite dish.
The Evolution Of PSTN
It has slowly evolved over the past few years. The first major change was pushed in the early 1960s. The then analog phone systems were adjusted into T1 carrier structures. Unlike the previous analog systems, this allows the use of 3 KHz of voice transmission signal. It is a wider voice channel but somehow it did not make it quite as big as what the inventors expected it to.
Digital transmission then progressed to the use of fiber optic cables. This kind of transmission cost much less than the analog ones which is why they were immediately embroced by the public.
Telephone Over IP
Now, there is also what we call the Voice over Internet Protocol or VoIP. This allows users to call using the telephone but channeling through IP networks. This internet telephone system is now widely used due to its affordability and reliability. Even businesses now employ the use of VoIP.
There is a marked disadvantage despite. In comparison to the usual phones, if there is a power interruption, VoIP functions cease without you use UPS or Uninterruptible power supply. Also, with this type of phone system, you do not have a stationary and fixed address. This can be a problem if you want to call fire department or 911. However, the advantages still do outweigh the disadvantages.
Source by Alan Cassidy