Information Technology Reference
In-Depth Information
Figure 3.9 The.original.dial.telephones.were.an.engineering.marvel.
at.the.time,.and.still.are.
to.a.base.station,.will.not.work.at.all.if.you.do.not.have.that.
outside.power.source..This.is.important.to.things.we.discuss.
later,.so.keep.this.in.mind.
There.are.a.few.other.electronics.in.modern.phones,.such.
as.special.speakers.that.create.ring.tones,.and.coils.that.keep.
you.from.hearing.your.own.voice.or.other.interference..But.
in.general,.that.is.really.all.there.is.to.this.simple.but.hugely.
important.piece.of.technology.
So,.you.picked.up.your.phone..If.you.are.lucky.enough.to.
own.one.of.those.wonderful.old.POTS.phones,.just.by.pick-
ing. up. the. receiver,. you. connected. to. the. system,. because.
the.switch.is.in.the.“hook.”.You.could.even.dial.using.pulse.
dialing.by.simply.tapping.the.hook.switch.quickly.the.number.
of.times.you.want.to.input.as.a.number..But.instead.of.doing.
that,.you.tap.out.grandma's.number.on.the.keypad.
When.you.picked.up.the.phone.and.connected.to.the.sys-
tem,.a.switch.opened.up.at.the.switching.station.we.talked.
about. earlier,. and. in. our. day. and. age,. a. computer. started.
listening.for.what.you.would.do.next.
But.let's.not.get.ahead.of.ourselves..As.noted.before,.this.is.
best.understood.if.we.consider.how.it.was.done.in.the.begin-
ning.and.then.work.our.way.up.to.the.way.things.are.done.
