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1.
Imagine a call being initiated, just like a
goalie looking to pass the ball to his player.
2.
When the number is dialed, the phone sends the
request to the cell tower it’s currently connected to- much like the goalie
passing the ball to his defender to take forwards.
3.
The call request is forwarded to the base
transceiver station (BTS) from the tower. This is like Xavi making a pinpoint
pass through the midfield to another Barcelona player.
4.
From the BTS, the call is connected to the base
station controller (BSC), which allots the call a frequency channel to
communicate over. This is akin to a football team keeping their shape, and
making sure they stay in their positions (or their allotted “frequency”).
5.
The call is now switched to a mobile switching
centre (MSC). If the call is for another user in the same home network, the
steps are retraced to the base station of the other user. This is like reaching
the goal mouth of the opponents’ goal and back passing all the way back to your
own goal line.
6.
If the call is for a user on another network
(another operator) the call is passed from the MSC to a gateway MSC that
switched the call to the appropriate operator’s MSC. Think of it as losing
possession to the other team.
7.
Here’s where football stops making sense in the
equation. Instead of play turning around, imagine if both teams wanted to
attack the same goal… The call is carried forward from MSC to BSC to BTS and
all the way to base station of the called party’s location.
8.
There’s also a home location register (HLR) that
each operator maintains, which knows which phone is where (or latched on to
which base station). Also, an authentication center (AuC) checks whether the
subscriber being called has the required authorization and credentials to
receive calls. So if you haven’t paid your bill or furnished proper documents,
the AuC is the one who gives you the red card – like a referee does.
9.
When all goes well, the correct subscriber is
connected to, and you hear ringing at your end, as the networks finally connect
the two phones – it’s like a forward taking a shot at the goal.
10. The
called party hears his phone ring. Think of them as the opponent’s goalie. If
the call goes unanswered or is rejected, it’s like a goalkeeper’s save, and you
start from scratch all over again.
11. When
the call is answered, it’s like a goal being scored, and the celebration begins
with a “Hello!”
12. Of
course it usually turns out to be a tele-marketer, trying to sell you something
you don’t really want or need. So it’s usually the mobile operator and the marketing
companies that celebrate most of the calls that get through!