Practical SIM cards in practice
(sorry for my earlier post..)
From a (finnish) users point of view it
works somewhat like this
- when signing up for a contract one gets the
SIM card, earlier programmed in the store, now
just from a box. (The SIM card has a serial number
which is sent to the operator, I believe, with the
details of the contract)
- one snip-snaps out the small size card form the
credit card size plastic, removes the handset
battery and puts,drops the card in its place.
- turns on the power to the phone, SIM card not
yet activated, tries again in some hours, and
then it is up and running (a matter of how
the information on this new contract has reached
the operator, some stores need to fax the operator,
some do it faster with a "machine", delay between
1-2 hours to one day, also depending on time of
purchase, internal procedures)
- the idea is to totally unbundle the contract and the
phone, one can move the "subscriber" to any phone.
- as a result one must also move user data from phone to
phone (compare computer-hard disk).
- That is, in addition to actual Subscriber Identification
the card also stores name-number lists, text messages
and some settings of the phone. However, the phone
have its own memory, so it is sometimes a little
confusing to know what is where when switching cards between
two or more phones. The size of the memory
vary between phones, also at least two types of
SIM cards around, old and new, more or less memory.
(the phone-SIM memory can be additionally password
protected, etc, something for Dr IJ)
- one service for which there is more and more demnd is
to copy name-number lists, archived messages, both
between cards (having two phones, need same data on
both) as well as making backups, down and uploading
to a PC,etc. (Girls collect messages like memorabilia
of first love,etc,etc, no one wants to reenter
even 20-50 names and numbers manually, but still few
desktops come supplied with IR ports, handsets
target people without computers,etc)
- one particular case is when a customer's SIM card
has been lost, damaged or is upgraded, the store
should destroy the old card immediatly but can
keep it intact, archive it, to make another copy
later if necessary or fill up the new card from
the old or a floppy.
- however, if two "same cards" are detected by the
network, both are disabled, and there is some hazzle
in turning one on again.
- prepaid, also anonymous cards are good for tourists,
to use local tariffs when traveling, but even better
for more shady individuals, alternatively shady
governments and honest individuals.
(shadier businessmen use many prepaid SIM cards, numbers
to avoid beeing tracked easily, when in action)
- traveling abroad one actually need two cards, one
"from home" and one to use locally. This until portable numbers,
switching to a local prepaid, lower tariff contract can
be done. (depends on roaming agreements between operators,
nations, but in general it is expensive to call locally
outside scandinavia with ones regular SIM card, some also
has one card for business use and one for private pleasure..)
- in general it is the computer generation kids
who do the SIM card swapping for their parents,
additionally one can actually make one mistake when
inserting the card.(one side must be inserted under
a small thingy, not just dropped in place, and one
should maybe not have too greasy fingers and touch the
contacts on the back side)
Ilmarinen.
P.S. Hmm, how many AMPS-TDMA-CDMA grandmas does it take
to swap one SIM card?? |
