Why does a cell tower need to be massive to transmit data to a smartphone but the phone’s extremely small antenna can transmit data back over the same distance?
In: 52
It is exactly because the phone has a small antenna and low powered. So if you think of a receiver and transmitter. The smaller the receiver ie the phone, the larger the signal it needs to “hear” things therefore the cell tower has to be large and powerful. And as the phone has a small transmitter, it emits a weak signal and the receiver (cell tower) needs to be large to “hear” it.
Also your phone is only dealing with one communication – that between your phone and the transmitter.
The transmitter on the other hand is dealing hundreds or even thousands of transmissions to and from hundreds or thousands of devices simultaneously. It needs to be big and powerful to be able to do that.
Think of a cell tower as a big, loudspeaker that needs to talk to many people who are far away. It needs to be big and powerful to send its message far and wide to reach all the people it needs to talk to.
A smartphone, on the other hand, is like a small microphone that needs to talk back to the loudspeaker. It doesn’t need to be as big or as loud because it only needs to send its message back to the loudspeaker which is closer. It’s also really good at listening to quiet sounds, so even if the loudspeaker is far away, the smartphone can still hear it and talk back.
Size of an antenna is correlated to how loudly it can transmit and how quiet of a signal it can receive.
Imagine a cellphone is your hearing-impaired grandma with laryngitis. If you want to have a conversation, with her, you have two options: get close enough for you two to hear each other, or get a loud enough voice and big enough ears to converse at your current distance.
A cell tower obviously can’t move and so has to just have a loud “mouth” and big “ears.”
The cell tower’s massive equipment can pick up even weak signal, while the phone’s small antenna needs to get a fairly strong signal to receive it reliably.