Mobile service in FM technology
The American telephone company IT & T started providing mobile telephone services using FM technology in 1947. The American telephone company started using FM technology to provide IT & T mobile telephone services in 1947. The mobile phone of that time is not like the mobile phone of today. Inside the car was a large 20-25 pound two-way radio (transmitter-receiver). There was an antenna outside.
These communicated with transmitters and receivers connected to a tall tower in the middle of the city. They were again connected to the telephone office – where the necessary communication was completed. In New York City, where about 20 million people lived in 1946, only 543 received this service! Only 15 FM channels were allocated for this service. A channel is a set of frequencies that are needed to carry messages over the air. The customer had no channel of their own in this technology. When he wanted to talk, he was given one of the 15 channels to talk to.
As soon as he finished speaking, it was given to the other customer who wanted to speak. In other words, this service could not talk to more than 15 customers at the same time. The sixteenth customer would not get the line if he wanted to speak. In the language of telephone, it is called ‘blocking’. This also happens on ordinary telephones at one and a half times – the dial-tone is not available as all the circuits are being used. But in a city like New York, if more than 15 people can’t talk to each other, that’s a problem. It is not difficult to understand why this mobile technology has not become popular.
The question may arise as to what was the problem if 1500 channels were given instead of only 15 channels. The disadvantage is that different frequencies are allowed for different tasks. There is no way to use the desired frequency. So what has been allocated has to be better utilized with better technology.