There are two broad categories of ICCs. Memory cards contain only non-volatile memory storage components, and perhaps dedicated security logic. Microprocessor cards contain volatile memory and microprocessor components. A smart card, chip card, or integrated circuit card (ICC) is any pocket-sized card with embedded integrated circuits. Smart cards can provide identification, authentication, data storage, strong security authentication for single sign-on (SSO) and application processing. Physical, electrical and other characteristic of Smart cards are described by the ISO / IEC 7810 and ISO / IEC 7816 series of standards. Smart Card (SIM Card) pinout Pin Name Description C1 VCC +5 VDC power supply input (optional use by the card) C2 RESET Reset signal, used to reset the card’s communications.
Sim world roaming free sim cards
Scheme of connecting a SIM-chip to a GSM-module Due to the identity of SIM-chips and SIM-cards, it is possible to connect a SIM-chip to one GSM-module in combination with a SIM-card. In this case, the developer of the device must ensure proper multiplexing between identification modules. If the developer almost does not have to edit the electrical circuit, the drawing of the printed circuit board will change significantly - a lot of space will be freed up on it.
The SIM-chip is made in the VQFN-8 form factor and occupies only 30 mm2 on the printed circuit board (Fig. 4). The pinout of the microcircuit is standard, it is shown in Fig. 5. Fig. 4. Overall dimensions of the VQFN-8 SIM-chip Fig. 5. Pinout of the SIM-chip Quick start Since SIM-chips can now be classified as electronic components, it became possible to purchase them from the official partner of the cellular operator.
Smart card (sim card) interface pinout
GSM devices in the operator's cellular GSM / UMTS network for accessing voice, SMS and digital data transmission via GPRS or CSD technologies. Historically, to identify a GSM device in the network, plastic-based SIM cards the size of a credit card (86 × 54 mm) were initially used, which had to be manually inserted into a mobile phone. In the process of popularization of cellular communication and with the advent of more and more compact mobile phones, the SIM card only decreased in size (25 × 15 mm), still remaining plastic (Fig.
2). Figure: 1. External view of the SIM-chip (5 × 6 mm) Fig. 2. The appearance of the SIM card To this day, the SIM card is a separate device and is distributed by mobile operators as a service that is primarily focused on the mass consumer market.
Phone sim card: device
Attention
This process has not spared the SIM cards (Subscriber Identification Module) used in all GSM devices. Familiar SIM cards have recently become available in a new form factor - in the form of microcircuits in a miniature VQFN-8 package. Such SIM-cards are more correctly called SIM-chips. The emergence of SIM chips on the market of electronic components for free sale has opened up new opportunities for the industry of GSM devices, such as transport monitoring and security systems, telecommunications and retail cash equipment, medical devices and telemetry complexes.
SIM chip - choice M2M SIM chips (Fig. 1) comply with the ETSI TS 102.671 standard and are designed to be mounted directly onto a PCB by soldering. Functionally, a SIM chip is no different from a regular SIM card (Fig.
Sim cards. problems and solutions
Then the workpiece is clad with a film from the bottom side and this film covers the adapter cavity, preventing the card from falling through. Problem # 2. The adapter clings to the contacts This design has very sharp and non-creasing corners in the area of \u200b\u200bcontact with the connector contacts. The zeal of the connector to ensure reliable contact can be easily traced on old types of "soft" SIM-cards.
Info
And the adapter very confidently and cocky clings to the contacts. Usually it is still possible to insert the unit into the connector, albeit with a dangerously excessive force (it is pushed in "along the grain"), but when pulled out ("against the grain") both parts "go to principle", and the procedure is possible only with tearing out one or two contacts connector. The adapter diagram is shown in the figure. The most dangerous is the internal "rib" indicated in the figure on the narrow crossbar of the adapter - it is this that tears out the connector pins.
SIM card
Russian mobile operators for their subscribers (legal entities) allow electronic document flow to simplify and speed up the process of connecting newly purchased devices with SIM-chips. Integration of the SIM-chip into the device It will not take a long time for the developer of the GSM-device to figure out how to connect the SIM-chip to the GSM-module. A chip, like a SIM card, has VCC, I / O, RST, CLK and GND contacts, and its connection scheme is almost the same as the SIM card connection scheme (Fig.
3), with one exception: there is no need for a protective diode in the case of SIM-chips, since the probability of damage to the lines by static electricity is excluded. Protective diodes are recommended for devices with SIM cards, where the user can touch the holder's electrical contacts and "discharge" to the device. Figure: 3.
Communication Secrets: Part 1 - Opening the SIM Card
A SIM card is a device that is a subscriber identification module. It is an integrated circuit designed to securely store the International Mobile Subscriber Identity (IMSI) number and associated key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). In addition, you can store contact information on many SIM cards.
SIM cards are always used on GSM phones, for CDMA devices they are only needed for new LTE-compatible devices. They can also be used in satellite phones. The SIM card is part of the Universal Integrated Circuit (UICC) feature, which is usually made of PVC with embedded contacts and semiconductors.
Simcard special connector at the card card pin Description 1 Vcc 2 Reset 3 CLK 4 GND 5 Vpp 6 I / O This information should be correct, but errors are quite possible. You can help! You can confirm the correctness of the document (only if you are really sure), or report an error in the document (the error can be described further on the link). Your opinion will be taken into account when calculating the status of the document.
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SIM card pinout
Important
MT-System, one of the largest suppliers of radio electronic components in Russia and the CIS, is the only company that officially supplies SIM-chips to the Russian electronics market. For quick testing of SIM-chips, MT-System offers developers SIM-chip-adapter adapter cards, similar in shape and size to SIM-cards (Fig. 6). The riser board with a SIM-chip soldered onto it fits into most SIM-card holders and does not touch the holder's elements.
Since the dimensions and pinout of SIM-chips are standardized, the "SIM-chip-adapter" can be used together with the SIM-chip of any mobile operator. Figure: 6.
Pinout of the gsm SIM card
In addition, there is no hole for a SIM-card holder in the case, which means that the device is moisture-proof and, which is important, it is vandal-resistant - it is impossible to remove the SIM-chip from it in order to insert it into a standard slot of a mobile phone, which excludes the possibility of inappropriate traffic consumption. SIM-chip access to cellular services The process of replacing SIM-cards with SIM-chips is a new direction in the Russian market of M2M electronics, which came from the West. As of today, all major Russian cellular operators have already mastered working with them and are ready to connect SIM chips embedded in any GSM device.
The life cycle of a device that uses a SIM chip can be divided into two parts - before and after the device is sold to the end user.
SIM card connector pinout
C7 I / O Input or Output for serial data (half-duplex) to the integrated circuit inside the card. C8 RESERVED AUX2, optionally used for USB interfaces and other uses. Please note that there are great variations in connector shape: Image from Wikipedia: The dialogue between the interface device and the card shall be conducted through the consecutive operations:
- connection and activation of the contacts by the interface device
- reset of the card
- answer to reset by the card
- subsequent information exchange between the card and the interface device
- deactivation of the contacts by the interface device
Interfacing smart card isn’t a simple task. Here is the Smart card to PC interface adapter cable scheme.
SIM card slot pinout
In the ROM memory, the mobile operator writes the operating system, the IMSI code, which is unique and provides identification of the SIM card in the network, the individual Ki key intended for encryption (to be more precise, using the Ki key and a random number generated using the algorithm A8 a 64-bit key Kc is created. The Ki key is stored on a specific SIM card and in the operator's database, is kept secret and is never transferred between the operator and the subscriber, and the Kc key is used to encrypt data transmitted between the cell phone and the base station of the network ). Also, encryption algorithms and some other codes are entered in ROM, including a list of allowed networks (TMSI codes - Temporary Mobile Subscriber Identity, LAI - Location Area Identification), PUK - Personal Unblocking Key to unblock the SIM card in case of three incorrect PIN entries -code.
Once upon a time, more than 20 years ago, which by the standards of the modern IT industry can even be considered untrue, mobile phones for self-identification in the network of a cellular provider used special numbers written in them at the factory. However, this approach was not very convenient for both users and manufacturers. They were interested in "decoupling" the caller ID from the equipment. This is how the idea of \u200b\u200busing additional individual cards with embedded microcircuits arose. This approach is used today in networks of various standards - GSM, CDMA, UMTS, LTE, but we will talk mainly about the most massive version - GSM / 3G.
The telephone set, as a physical device, is left with the IMEI (International Mobile Equipment Identity) number, which can be considered unique on a global scale. It participates in the logs of operations of a cellular operator and, in principle, can be used to block access to the network, search for stolen phones and other similar actions. It is illegal in some countries to counterfeit and alter this number. The IMEI number can usually be found on a sticker under the battery and on the box. From a technical point of view, it is recorded electronically in one of the microcircuits and, of course, can also be read programmatically. If the phone has the ability to install several SIM-cards, then there are also several IMEI numbers. This number is available not only for phones, but also for modems, tablets and other devices designed to work in mobile networks. Formally, manufacturers could do just that number and not use traditional serial numbers for their products, but today such a "separate" approach is more convenient for them.
A similar SIM card number is called ICCID (Integrated Circuit Card Identifier). It is often engraved on the cards themselves. It is similar to the serial number of the device - the only difference is that it is unique and is not repeated on any other card in the world. Although if you add the manufacturer and the model name to the serial number of the phone, then this combination will also be unique.
The subscriber is directly identified in the cellular network by the IMSI (International Mobile Subscriber Identity) number, which is recorded in the SIM card. This number identifies the identity of the card to the operator and allows you to link the card user to his account with the provider, including the phone number, permitted services, and so on. The map also stores other unique information, the description of which is beyond the scope of this article.
A few words should be said about card protection. The first line is a four-digit PIN. If you do not know it, you will not be able to use the card to access the cellular network or to read the address book. The user can change or cancel this code (it is usually disabled on newly purchased cards). If the PIN-code was dialed incorrectly several times, you need to use the PUK code, which is also provided by the operator along with the SIM-card, to unblock. Even less commonly, PIN2 and PUK2 codes are used, which allow the user to restrict the list of allowed subscribers for outgoing calls.
But even if you know all these codes, you will not be able to copy the card using household methods. Inside it is another special code, known to the operator, which is used in the identification algorithm. This process is arranged in such a way that the pure code is not transferred from the card to the phone. Instead, the machine sends a key encryption task to the SIM card processor, and sends the answer to the operator. The latter compares the result with that obtained in his data center, and if they match, the subscriber gets access to the network.
One of the popular options for "full-size" smart cards today
Technically, a SIM card is one of the variants of smart cards - microcomputers with their own processor and memory that communicate with the outside world through an interface of several electrical contacts. Smart cards are found today in the banking sector, are used to control access and in various payment systems. Usually the card has several kilobytes of permanent memory, a couple of kilobytes of RAM and some flash. In the case of telephones, the latter was previously used to store a notebook, but the limitation on the number of entries (250) and support for only two fields (name and phone) have practically deprived him of this role today.
The electronic filling takes up very little space
Formally, the card has eight contacts for connecting to a reader (if you try very hard, you can try to count even more). However, in reality only six are used. And given the modern progress in microelectronics, the filling takes literally a few square millimeters.
But if we talk about external dimensions, it all started with a credit card format - 85.6 x 53.98 x 0.76 mm. This smart card format is still in use today, but it has long ceased to satisfy the wishes of cell phone manufacturers. Much more practical is the Mini-SIM version, which measures 25 × 15 mm with a beveled corner (to determine the required orientation of the card in the slot). The thickness did not change. It is this format that is the most widespread today and is found in most cell phones.
Mini-SIM and Micro-SIM cards use much less plastic
It is clear that such a reduction did not bring any losses in terms of functionality. But you have to understand that Mini-SIM is good for placing in a telephone case. Using a card of this size, for example, for payphones is obviously inconvenient.
After the massive transition to the Mini-SIM format, for a very long time it remained practically the only option for use in the field of mobile communications. Even the successes in reducing the external size of telephone sets did not require further reduction of the subscriber card. But still, he was not allowed to gain a foothold for centuries.
To install Micro-SIM (sometimes Mini-SIM), special frames can be used
Two and a half years ago, one of the most active market players in his new smartphone model implemented work with the Micro-SIM format, the size of cards of which is 15 × 12 mm (the thickness has not changed again). For cards of this format, almost the entire front surface was already occupied by contact pads. But even for him there were no technical difficulties in placing the chip, especially with the development of technologies for manufacturing microcircuits. Note that in terms of consumer device design, the market did not require this step. So, rather, the company played in the field of marketing, once again repeating "we are not like everyone else."
The electronic "filling" takes up very little space even in Mini- and Micro-SIM
Interestingly, the same manufacturer played this card again this year. The latest model of their smartphone works exclusively with Nano-SIM, in which the thickness has already been reduced - 12.3 × 8.8 × 0.67 mm. Eight standard contacts no longer fit into this format, so only six truly working ones remain. None of the technical features of the card were affected this time, but the dimensions of the new phone are not as small as one might think (and some even increased).
Almost the entire front surface of the Nano-SIM is occupied by contact pads
A very reasonable question arises: how does this miniaturization story affect consumers? If we talk about those who buy a new phone with a contract and a new card, they usually don't care which version of the SIM card is installed in it. And if a person has only one phone or he does not plan to rearrange the cards, then not even “usually”, but “completely”.
To install Micro-SIM into the Mini-SIM compartment, you can use adapter adapters
But for those users who are used to using several devices and / or SIM-cards, the situation is less pleasant. In the case of a Mini / Micro pair, you can try to get by with so-called adapters / adapters (of course, after changing all Mini format cards to Micro format cards). There are no pluses in this story, only minuses - you need to carry additional parts with you, and besides, the adapter can damage the connector pins during replacement (or the assembled structure may even get stuck in the slot).
As for changing cards, the official way is to visit your operator's salon, write a statement, wait and all that. In addition, if you suddenly have any records on the map, you will need to take care of saving them. A more affordable option in terms of time consumption is to contact numerous workshops, where your card will be cut with a special tool in a couple of seconds (by the way, large salons and even the operators themselves do this). If you really don't want to go anywhere, then a sharp knife and a strong hand are also capable of successfully solving the problem. For the first time, a printout from the Internet with a "cutting" scheme may be useful (see for example).
With Nano-SIM, the situation is more complicated, since both the linear dimensions and the thickness of the card are smaller. The methods remain the same. But the first of them should be recognized as the most correct at present. However, given the prevalence and cost of the device, for which you may need a Nano-SIM, this should not be a problem.
Today, every mobile owner has at least one SIM card. We are so used to these little pieces of plastic with gold-plated contacts that we don’t even think about what miracle of technology we are using.Picture on the theme "Secrets of SIM-cards"
How SIM cards appeared
SIM stands for Subscriber Identification Module or Subscriber Identity Module. As the name suggests, a SIM card is used to identify a subscriber in a cellular network.
SIM card
At first, the identification of the user in the network was carried out, guided only by the serial number of the cell phone -. When there were few subscribers and equipment manufacturers, this approach justified itself. As a result, the equipment, that is, the cell phone and the subscriber, were identified by a single code. Among other things, this approach gave rise to the complete dependence of, say, a package of services and a phone number on the device. That is, having changed your cell phone, you had to go to the operator's office in order for the serial numbers of your phone to be entered into the database. If the mobile phone broke, it took some time for you to use the communication services again.
It would be much more convenient to identify the subscriber independent of the telephone. This idea was guided by the developers of the GSM standard, who proposed to separate the identification of subscribers and equipment. The Finnish company Radiolinija was the first to apply this idea in 1991.
The proposed identification scheme is valid to this day. In particular, as we have already said, a SIM card is used to identify a subscriber in GSM cellular networks (as well as in many others). For completeness, we note that modern cell phones are identified by the system using a 15-digit number - International Mobile Equipment Identifier).
Having talked about the history of SIM-cards, let's try to take a closer look at these interesting devices.
What is a SIM card: purpose and development
In short, a SIM card is a computer. The SIM contains a microprocessor, buses for input and output of information, a set of types of memory typical for computers: ROM (permanent), RAM (operative), EEPROM (rewritable). The card stores various data, some of which it handles with extreme care in order to ensure the safety of the subscriber.
In particular, the following information is stored on the card:
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Posted by: bourbon
hello!
but even so tell me how to break it so that it looks almost as it was, before the breakdown
Posted by: Clever Anonymous
Listen to the last obzats talking about pin and pack codes. But think about it, the more protection, the worse you are. If your phone is blocked, anyone can open it, but if someone is not blocked, maybe they will call you.
Posted by: Andrey
I have such a question whether it is possible to find my sim card, which is working at the moment, but I don’t know where the phone is
Written by: evgen
please tell me how you can break COMP128v2 anyway, otherwise I will not copy SIM cards of the new generation of the International Federation of Journalists who knows what ????
Posted by: sexmachine
USE HERE Id 9503140707
Posted by: LOH
do not store imsy and kai on your computer
A smart card, chip card, or integrated circuit card, is a pocket-sized card with embedded integrated circuits. Described by ISO7816 standard. Used in cellular phones, pay TVs, ATM cards, etc.
There are two broad categories of ICCs. Memory cards contain only non-volatile memory storage components, and perhaps dedicated security logic. Microprocessor cards contain volatile memory and microprocessor components. A smart card, chip card, or integrated circuit card (ICC) is any pocket-sized card with embedded integrated circuits.
Smart cards can provide identification, authentication, data storage, strong security authentication for single sign-on (SSO) and application processing.
Physical, electrical and other characteristic of Smart cards are described by the ISO / IEC 7810 and ISO / IEC 7816 series of standards.
Smart Card (SIM Card) pinout
| Pin | Name | Description |
|---|---|---|
| C1 | VCC | +5 VDC power supply input (optional use by the card) |
| C2 | RESET | Reset signal, used to reset the card "s communications. Either used itself (reset signal supplied from the interface device) or in combination with an interal reset control circuit (optional use by the card). If internal reset is implemented, the voltage supply on Vcc is mandatory |
| C3 | CLOCK | Provides the card with a clock signal, from which data communications timing is derived |
| C4 | RESERVED | AUX1, optionally used for USB interfaces and other uses. |
| C5 | GND | Ground (reference voltage) |
| C6 | Vpp | Programing voltage input (optional). This contact may be used to supply the voltage required to program or to erase the internal non-volatile memory. ISO / IEC 7816-3: 1997 designated this as a programming voltage: an input for a higher voltage to program persistent memory (e.g., EEPROM). ISO / IEC 7816-3: 2006 designates it SPU, for either standard or proprietary use, as input and / or output. |
| C7 | I / O | Input or Output for serial data (half-duplex) to the integrated circuit inside the card. |
| C8 | RESERVED | AUX2, optionally used for USB interfaces and other uses. |
Please note that there are great variations in connector shape:
Image from Wikipedia:
The dialogue between the interface device and the card shall be conducted through the consecutive operations:
- connection and activation of the contacts by the interface device
- reset of the card
- answer to reset by the card
- subsequent information exchange between the card and the interface device
- deactivation of the contacts by the interface device
A SIM card is a device that is a subscriber identification module. It is an integrated circuit designed to securely store the International Mobile Subscriber Identity (IMSI) number and associated key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). It is also possible to store contact information on many SIM cards.
SIM cards are always used on GSM phones, for CDMA devices they are only needed for new LTE-compatible phones. They can also be used in satellite phones.
The SIM card is part of the universal function (UICC), which is usually made of PVC with embedded contacts and semiconductors. A SIM card, the device of which is based on digital technology, can transfer data between different mobile devices.
The SIM card contains:
- unique (ICCID);
- international Mobile Identifier (IMSI);
- authentication and encryption;
- temporary information about the local network;
- a list of services to which the user has access;
- the phone's SIM card device also has two passwords: a Personal Identification Number (PIN) for normal use and a Personal Unlock Code (PUK) for unblocking a PIN.
History and market entry
The SIM format was originally defined by the European Telecommunications Standards Institute in a specification with the number TS 11.11, which describes the physical and logical properties of a SIM card. With the development of UMTS, the specification work has been partly moved to 3GPP.
The first SIM card was developed in 1991 by Munich-based smart card manufacturer Giesecke & Devrient, which sold its first 300 copies to the Finnish wireless operator Radiolinja.
Inactivation
In many pay-on-the-go contractual agreements, you must periodically use prepay to avoid account expiration. This period depends on the network operators, but is usually defined as a period of three months. This is sometimes due to the SIM card becoming inactive on the network.
registration
Most countries and operators require identification to activate the service, but there are some exceptions such as the Hong Kong SAR.
How does a phone SIM card work?
There are three operating voltages for SIM cards: 5 V, 3 V and 1.8 V. The operating voltage of most SIM cards launched before 1998 was 5 V. Subsequently, the cards are compatible with 3 V and 5 V. Modern copies support voltage 5 V, 3 V and 1.8 V.
Data
SIM cards store network information used to authenticate and identify subscribers on the network. The most important ones are ICCID, IMSI, Authentication Key (Ki), Local Area Identifier (LAI), and Operator Number.
The SIM card whose device is based on schemas also stores other carrier-dependent data such as the Short Message Service Center number (SMS ServiceServiceName), Service Provider Name (SPN), Service Number Numbers (SDN), Advanceofcharge parameters and applications with value added (VAS).
SIM cards can be supplied in various data sizes from 8 to at least 256 KB. All of them allow for a maximum of 250 contacts, but if the 32K version has room for 33 mobile network codes (MNCs) or "network identifiers", the 64K version has room for 80 MNCs. This metric is used by network operators to store information about preferred networks and is mainly used when the SIM is not in its home network, but in roaming. What does this phone sim card device mean?
The operator who issued the SIM card can use this to connect the phone to their preferred network in order to use the best business deal for the original network company. This does not mean that a phone containing this SIM can connect to a maximum of 33 or 80 networks, but only that the issuer of the SIM card can only indicate up to this number of preferred networks. If the SIM is outside of these preferred networks, it will use the first or best available.
ICCID
Each SIM is identified internationally by an Integrated Circuit Identifier (ICCID). ICCIDs are stored on SIM cards and are also engraved or printed on the case during the personalization process.
ICCID is identified by ITU-T E.118 as the Primary Number. Its layout is based on ISO / IEC 7812. According to E.118, the number can be up to 22 digits, including one check digit calculated using the Luna algorithm. However, GSM Phase 1 has defined the ICCID length as 10 octets (20 digits) with a specific operator structure.
International Mobile Subscriber Identity (IMSI)
SIM cards are identified in individual operators' networks using a unique international mobile subscriber identification (IMSI). Operators connect to mobile phone calls and exchange their SIM cards in the marketplace using their IMSIs. Their format is as follows.
The first three digits represent the Mobile Country Code (MCC).
The next two or three digits represent the Mobile Network Code (MNC). Three-digit MNCs are permitted by E.212, but are primarily used in the United States and Canada.
The following digits represent the Mobile Subscriber Identification Number (MSIN). This is usually 10 digits, but the value will be less in the case of a three-digit MNC or if national regulations specify that the total length of the IMSI should be less than 15 digits. All these numbers differ from country to country, so there may be differences in how the SIM card works. The scheme is standard and factory, the difference is observed only in the recorded information.
Authentication Key (Ki)
Kni is a 128-bit value used to authenticate SIM cards to the GSM mobile network (for the USIM network you still need Ki, but different parameters are required). Each SIM has a unique Ki assigned to it by the operator during the personalization process. This parameter is also stored in a database (called an Authentication Center, or AuC) on the carrier's network.
How is the SIM card arranged taking into account the above? It is designed to prevent Ki from being received via the smart card interface. Instead, the SIM card provides a "Launch GSM Algorithm" function that allows the phone to transfer data to a SIM card that must be signed with Ki. This, in theory, makes the use of a SIM card mandatory if Ki cannot be extracted from the SIM card or the operator wishes to disclose this parameter. In practice, the GSM cryptographic algorithm for computing SRES_2 (see step 4 below) from Ki has certain vulnerabilities that can allow extracting this value from the SIM card and creating a duplicate SIM card.
Authentication process
When the mobile equipment starts up, it obtains the International Mobile Subscriber Identity (IMSI) from the SIM card and sends it to the mobile operator, requesting access and authentication. Mobile equipment can transfer the PIN to the SIM card before it reveals this information.
Location area identification
The SIM stores information about the state of the network, which is received from the location area identifier (LAI). Operator networks are divided into locations, each with a unique LAI number. When the device changes location, it saves the new LAI on the SIM card and sends it back to the carrier's network with the new location. If the device works cyclically, it will retrieve data from the SIM card and search for the previous LAI. Some eavesdropping devices with a SIM card also work on this feature.
SMS messages and contacts
Most SIM cards will store some number of SMS messages and phonebook contacts by default. Contacts are stored in simple name and number pairs: entries containing multiple phone numbers and additional phone numbers are usually not stored on it. Such conditions are provided by a SIM card device. Contacts can be saved to a very limited extent. For example, when a user tries to copy such entries to a SIM card, the phone software splits them into multiple entries, discarding any information that is not a phone number.
The number of contacts and messages stored depends on the SIM card. Early models will only store five messages and 20 contacts, while modern SIM cards can usually store over 250 positions.
SIM card: device and formats
Over the years, SIM cards have become smaller, and their functionality does not depend on the format. The full-size SIM was followed by mini-SIM, micro-SIM and nano-SIM. Today they are even built into devices.
Full size SIM
The full-size SIM card (or 1FF, 1st form factor) was the first form factor. It has the size of a credit card (85.60 x 53.98 x 0.76 mm). Later, smaller SIM cards were often sold embedded in a full-size card from which they could be pushed out.
Mini-SIM
A mini-SIM (or 2FF) card has the same contact device as a full-size SIM card, and usually comes in a full-size adapter with connectors attached to it. This scheme allows it to be used both in a device that requires a full-size card and in a device that requires a mini-SIM card (after breaking the connectors). Since the full-size SIM is no longer used, some vendors refer to this form factor as a standard or regular SIM.
Micro-SIM
The micro-SIM (or 3FF) card has a similar thickness and contact arrangement, but is characterized by a reduced length and width.
The micro-SIM format was introduced by the European Telecommunications Standards Institute (ETSI) for installation in devices too small for a mini-SIM card. The form factor was mentioned in the 3GPP SMG9 UMTS Working Group, which is the standard setting body for GSM SIM cards, in December 1998, and subsequently agreed at the end of 2003.
Micro-SIM was developed for the main problem was the contact area of \u200b\u200bthe chip. Keeping the same contact area allows the micro-SIM to be compatible with previous, larger SIM card readers by using plastic cutouts. The device was also designed to operate at the same speed (5 MHz) as the previous version. The same size and position of contacts has resulted in numerous tutorials and YouTube videos with detailed instructions on how to trim a mini SIM to the size of a micro SIM. However, such actions at home sometimes lead to the fact that, as a result, the SIM card does not match the device or even becomes unusable.
Nano-SIM
The nano-SIM (or 4FF) card was introduced on October 11, 2012, when mobile service providers in various countries began shipping it for phones that support this format. The nano-SIM measures 12.3 x 8.8 x 0.67 mm and reduces the previous format to the contact area while maintaining existing functions. A small bead of insulating material remains around the contact area to avoid short circuits. The nano-SIM is 0.67mm thick compared to its predecessors' 0.76mm. 4FF cards can be placed in adapters for use with devices designed for 2FF or 3FF SIM cards and made thinner for this, but many telephone companies do not recommend this.
The iPhone 5, released in September 2012, was the first device to use activated nano sim cards, followed by other phones.
The upcoming new generation of SIM cards is called e-SIM or eSIM (embeddedSIM), which is a non-replaceable embedded chip in a SON-8 package - soldered directly onto the circuit board. It will have M2M and remote SIM capabilities.
