SIM is an acronym for “subscriber
identity module” which is an integrated circuit. Sim is a most popular
technology which is used in mobiles and tablets to communicate with others and
server system. It is embedded into plastic frame called as sim card that can be
removed and inserted into different mobiles .the first sim card was made in 1991
by Giesecke and Deviant of Sagem communications in France.it has a small memory
which securely stores international mobile subscriber identity number(IMSI) and its related keys such as integrated
circuit card identifier (ICCID),Authentication key or Ki, local area
identification(LAI),temporary information of network, some of the services the
user can access to, a personal identification number(PIN),personal unblocking
code(PUK).it also holds contact details and messages.
International mobile subscriber identity (IMSI): The IMSI is used to identify the user of cellular
network .it is a primary key associated with all cellular network.IMSI is
usually presented as a 15 digit number but can be shorter which is sent by
phone to the network.it is also used for acquiring more details of the mobile
in home location register (HLR) which is a central database that contains each
mobile phone subscriber that is authorized to use mobile communication network.
The HLRs store every sim card details issued by the mobile phone operator.
Integrated
circuit card identifier (ICCID): The ICCID number is stored in
sim and also printed on sim card. Generally IMEI is used to identify your cell phone whereas
ICCID is used to identify your sim internationally.it is a unique serial number
that represents the sim that a user has subscribed. An ICCID number will
consists of 19 to 20 characters.
For example, this ICCID number=8991101200003204510
provides details as follows
·
The first two
digits (89) represent Major industry identifier.
·
The next two
digits (91) represent county code.
·
The next two
digits (10) represent issuer identifier number.
·
The next four
digits (1200) represent month and year of manufacturing.
·
The next two
digits (00) represent the switch configuration code.
·
The next six
digits (320451) represent sim number.
·
The last digit (0)
is a check sum digit used to error detection. This digit was calculated using
luhn algorithm.
The ICCID is also used to track your phone if you lost.
Your network operator can help by tracing your mobile number that is linked to
ICCID number. This is because ICCID is linked to your phone that you have lost.
If the sim card is removed, then the further option to trace mobile is IMEI (international
mobile equipment identity) which is linked to mobile.
Authentication
key or Ki: it is 128 bit used to authenticate a sim on mobile network.
Each sim has unique authentication key assigned by the opearator.The
authentication key is also stored in database of carrier’s network. When mobile
is activated using sim card, the IMSI code is transferred from mobile to
network operator for authentication. The operator data base generates signed response
SRES_1 to the mobile phone and SIM then produces SRES_2 which passed into
network opearator.the network operator compared the SRES_1 and SRES_2 .if they match,
the SIM is authenticated.
Local area
identity (LAI): Operation network for mobile devices are divided as small
location areas. Each location area has a unique identification number. A phone
will store the unique number in the SIM so that knows what location the mobile
is in and able to receive service.
Personal identification
number (PIN): The pin is a code keep the information on your mobile
safe by locking your sim. The default pin code is 1234.if you set up a pin; you
will have to enter the pin every time when you turn the mobile on.
Personal unblocking
key (PUK): if you enter pin code incorrectly three times in a row,
you will have to enter puk code for unblocking your sim.
You can get puk code on the sim card.
NOTE: if you enter puk code incorrectly 10 times in a row,
it will be permanently blocked and cannot be reactivated.
Depending on the size, there are five types of sim
cards:
1.
Full size sim
2.
Mini sim
3.
Micro sim
4.
Nano sim
5.
Embedded sim
1. Full
size sim (1FF, 1st form factor):
This is the first type sim card and in fact
size of credit card.it is huge and outdated.it has the size of 85.60mm x
53.98mm x 0.76mm and it was used to fit into much larger phones.
2. Mini sim
(2FF, 2nd form factor): this is also outdated.it is smaller than Full size sim
but it is also larger compared to today’s standards.it has the size of 25mm x
15mm x 0.76mm.
Some of the phones used with Mini sim cards are listed
below:
Apple iPhone 3GS, Blackberry 9720, HTC Desire 310, LG
L70, Samsung Galaxy Ace, etc.
3. Micro sim
(3FF, 3rd form factor): The Micro sim was introduced by European Telecommunication
standard Institute. Now days these are used in most of the smart phones and
tablets.
Some of the phones used with Micro sim card are listed
below:
Apple iPhone 4, HTC desire 500, Black Berry Q10,
Motorola Moto E, etc.
Some of the phones used with Nano sim card are listed
below:
Apple iPhone 5, Apple iPhone 6, Motorola Moto X, Nokia
Lumia 930,etc.
5.
Embedded sim (Electronic sim): upcoming new generation of sim is called e-sim (embedded
SIM) which is non-removable chip .it is soldered onto the board as part of the manufacturing
process. Present only one device has the embedded sim feature that is Apple
ipad pro 9.7. You can use Nano sim slot, if you need it.
