Mini SIM Cards: A Tiny Revolution in Mobile Connectivity

1. Introduction

In 1991, SIM cards – which are an abbreviation for Subscriber Identity Module – were first created. They were roughly the size of a credit card and are still widely used in the present day. Mini SIM cards were obtained from their full-size predecessor, they released the same technology much less bulky and with the dawn of the smartphone era, this was revolutionary. Since the arrival of smartphones, SIM cards have developed even further. However, the technology behind them remains relatively identical. The customary chip SIM card is precisely just that; a microchip that connects to a mobile network. The metal contacts allow the mobile to electrically connect to the chip, and the data on the chip itself contains all the knowledge required to authenticate and track a phone. There are multiple different forms, from Micro and Nano to the more timeless customary chip. Every different form of SIM card offers an identical function, just in a smaller, more space-saving form. Regardless of the size, each one has the same chip inside, which is programmed to supply a singular key and data about the mobile it’s in reference to.

1.1. Evolution of SIM Cards

Over the entire progress of mobile telecommunication technology, SIM cards have gone through a series of modifications from full to micro and then to mini form. It was in the 1990s that the SIM card first came into existence. The earliest SIM card experts describe it as a “credit card” size. It measured 85.60 mm by 53.98 mm and has a 0.76 mm thickness. This actually increased read and writing errors. With technological progress, there was a need for smaller and better mobile telecommunication accessories. Well, experts in telecommunication technology were well aware of the place of technology and the demands of consumers. In the year 2003, the 2FF format of SIM card came into existence. This is usually called a “mini” SIM card. It has a dimension of 25.00 mm by 15.00 mm with a 0.76 mm thickness. Further in the year 2010, some experts started to carry out a project on yet a smaller and advantageous form of SIM card; the 3FF format. It is often referred to as a micro SIM card and has a dimension of 15.00 mm by 12.00 mm with a thickness of 0.76 mm. It is believed that this was the perfect form of SIM card that will fit into the future smartphones of technology. However, by the year 2012, mini SIM cards were known and used all over the world. On top, further experiment and project on an even smaller form of SIM card ended up with the development of the 4FF format of the SIM card. This SIM is usually called a nano SIM card, having a dimension of 12.30 mm…

1.2. The Need for Mini SIM Cards

In 2003, the company, Goswami, requested a patent for the creation of a new and smaller SIM card, which is now known as the mini SIM cards. He argued in the patent that the conventional full-size SIM cards cannot fit the upcoming launch of slim and sleek cell phones because of the large area that it occupies. He suggested that the modules that have metal contacts on the circuit board could be removed in order for the SIM card itself to be made smaller. He proposed to remove the excess insulating material and perimeter of the SIM cards while keeping the dimensions of the chip and the position of the metal contacts unchanged. His suggestion, now widely used by many technology companies, has overcome the problems associated with the full-size SIM cards. This is because when the manufacturers decided to replace the full-size SIM cards with the mini SIM cards in the market, the present designs of cell phones that favor the use of full-size SIM cards are still supported by the mini SIM cards.

The trend of shrinking the size of mobile phones started in 1979 when the first cell mobile phone was launched. The cell mobile phone was so large that it had to be carried in a bag. Gradually, technology advanced and the size of cell phones started to get smaller and smaller, but the size of the SIM cards remained big as compared to the size of the cell phone. In 1996, when the Subscriber Identity Module (SIM) card was created, it had the same size as a credit card. At that time, because of its large size and the large size of mobile phones, there was no issue. But as the cell phones started to get smaller in size, there arose a need to shrink the size of SIM cards as well.

2. Advantages of Mini SIM Cards

The use of smaller components in making a mini SIM card has translated into more convenience for mobile phone users. This is due to the fact that the mini SIM card is only about 25% smaller than the conventional SIM card. The reduction in size has also helped manufacturers to come up with mobile phone designs that have integrated the latest technological advancements such as touch screen features while at the same time maintaining a reduced weight and overall size of the mobile phone. The mini SIM card is able to comfortably fit into the allocated card slot in the mobile phone and the chances of it protruding and getting in the way of the user or getting knocked out of place are minimal. With the conventional SIM card, there was always an issue of not being able to use it in small personal multimedia devices. This is because such devices cannot accommodate the full size SIM card and the options of using an adapter combined with the fact that the adapter and the SIM card would have to maybe secured did not help the situation. However, all these problems have been eliminated through the use of mini SIM card since the card can fit into virtually any mobile phone or personal multimedia device. Also the problem of having to use an adapter had been eliminated. The mini SIM card also enhances compatibility with other devices such as a computer or a mobile network top up machine.

2.1. Smaller Size, Bigger Convenience

With the reduction of size, mini SIM cards also increase convenience for mobile phone and device users. Compared to the full-size standard SIM cards that were used on many mobile devices till recently, mini SIM cards are significantly smaller in size at 25mm x 15mm x 0.76mm, yet they provide the same functionality as the full-size SIM cards. This means that users can have mini SIM cards inserted into their mobile devices or cell phones and the devices will take smaller physical space while not compromising on the functionality that the SIM cards deliver. One case in point of this advantage is the user of mini SIM cards on the latest smartphones like iPhone 5, Samsung Galaxy S4, and HTC One; since they all use mini SIM cards, it’s possible for these mobile phone manufacturers to design and produce even smaller and thinner phones because less physical space is needed for the SIM card slot – before the introduction of mini SIM cards, these phones were using standard SIM cards. Therefore, many modern mobile phone manufacturers are taking advantage of mini SIM cards by producing newer phones that use mini SIM cards and reclaiming physical space for other hardware components or improve the phone design. Alongside the reduction in SIM card size, mini SIM cards offer bigger convenience by minimizing the cumbersome processes of swapping and replacing phone numbers and contents for mobile phone users who want to change their phones. If a new phone uses a mini SIM card but a user’s old phone has a standard SIM card or vice versa, a trip to the mobile network operator’s store or the phone dealer is needed to obtain a new SIM card, physically cut the new card into a required mini SIM card size, and install it into the new phone. This process involves making backups of phone numbers, short messages, and other contents on both the old and new devices, which can be time-consuming and inconvenient for users. Four of the six leading mobile phone providers in the United States of America offer SIM cards in mini form. All kinds of phone contracts are available with mini SIM cards, from pay-as-you-go, one-month rolling contracts, 12-month contracts, and 18-month/24-month contracts. These mini SIM cards can be used in any smartphone that’s mini SIM compatible – provided the phone can accept a mini SIM card, the network provider uses SIM card technology, and the phone is not locked to a specific network.

2.2. Improved Compatibility with Devices

Major tech companies across the board have committed to the recent evolution of digital memory processing and storage and have shifted to manufacture their devices to be compatible with mini SIM cards. Due to the slight difference in size of the mini SIM cards and the standard SIM cards (with the mini being much smaller), using mini SIM cards requires either a SIM card adapter or a mobile device that has been specifically altered to accommodate mini SIM cards. Innovative tech giants such as Apple and Samsung have already recognized the global propulsion of the mini SIM revolution, and there have been reports in the mobile industry that Apple in particular had designed the iPhone 4 with a slot that exclusively accepted mini SIM cards. In addition to this, the mini SIM card technology also has the ability to record and store highly detailed and personalized information for a user, thus enhancing the overall quality of service that can be offered by network providers. For example, on a mini SIM card, a user can overwrite some of the pre-loaded services from the network provider with services that they have fetched from the internet, thus personalizing their mobile experience. Some network providers have also suggested that they can preload the mini SIM cards with unique security keys or sensitive information that can be utilized for connecting with secure network services, potentially paving the way for a more comprehensive and sophisticated network security investment. Trending industry reports indicate that even though mini SIM cards are a relatively new and advanced stage of digital memory and network connectivity, the process of further miniaturization and development of SIM card technology is already underway. It is understood that the next form of SIM card technology – the nano SIM – has already been agreed upon by the European Telecommunications Standards Institute, and reports have been circling the industry that manufacturers are progressively moving towards adopting the new nano SIM standard.

2.3. Enhanced Security Features

Mini SIM cards have been a groundbreaking innovation in the mobile technology industry. Given their diminutive size, it is not surprising that one might overlook the fact that these small wonders provide a level of security comparable to what credit cards use. Mini SIM cards, also known as standardized Integrated Circuit Cards, earned this praise due to improved security. The card has a built-in secure logic and a secure memory to provide a better defense against cloning and security threats. The card has a more advanced encryption functionality, which is used to authenticate the card in the network. As advancements are made in the mobile technology industry, SIM cards have also evolved from the regular to micro and now to mini SIM cards to save on space and reduce errors that might come from big cards or wrongly inserted cards. The mini SIM card technology was designed to incorporate latest security features and enhancements as compared to its predecessors. For instance, it is not possible to install a mini SIM card in a wrong slot since there is only one slot available in the device machine. Furthermore, the mini SIM card tray in a device is designed in such a way that the position of the inner area is strictly to the high side, giving a fix on how the mini SIM card must be aligned. With these advancements, it is almost impossible to install or insert a mini SIM card in a wrong slot or in a wrong orientation. The metal skin surrounding the mini SIM card provides improved contact to prevent signal interference. The card normally comes with a factory locked PIN to avert unauthorized use. Through identity protection, utility companies have been able to use SIM cards in reducing incidents of fraud and securing private information.

3. Implementation of Mini SIM Cards

Thus, the USIM first verifies whether the device is using the network. The device acknowledges the commands sent before reading the USIM, which sends the proper and correct data to the device subsequently. After the data is processed by the USIM, it selects the preferred network and the device is registered to the network chosen. In addition, the USIM helps to authenticate and identify the subscriber to the network. The data within the USIM may include password and pin for security. When the USIM has successfully identified a device to a certain network, the device and the USIM will remain registered to that particular network till the USIM is removed. However, if the device is switched off, the USIM will from time to time search for the particular network automatically without the knowledge of the user. A special requirement for the USIM is that it should never store temporary mobile subscriber data received from the visited network during the Roaming. This is not allowed for Visa USIM whereby upon initialization, the Visa USIM should send the command to the device informing the device that Roaming should be prohibited. Only data received from the network is allowed. However, the standard USIM card takes several commands such as select, which initiates the application within the USIM by specifying the relevant application in the response to a select command.

3.1. Transition from Standard SIM Cards

Proper functioning of mini SIM cards highly depended on the ease and smoothness in transition from the existing standard SIM cards to new mini SIM cards by the mobile phone manufacturers and service providers. The solution was not that easy but it was manageable. Before the manufacturing process would take off, the standard SIM cards used a much larger credit card size design but lacked the efficiency and practical application as it may not be suitable for some of the smaller mobile phone models. The contacts and the communication chip were the same as the credit card size design as stipulated in the ISO standard 7816 just for compatibility with the existing system before mini SIM cards and micro SIM cards would appear in the market years later. The ISO standard 7816 specifies the physical characteristics of the integrated circuit cards with 85.60 mm x 53.98 mm for the ID-1 as in credit card size design in comparison to the mini SIM card size 25 mm x 15 mm and the micro SIM card size 15 mm x 12 mm. However, it was the configuration of the materials and the components in a SIM Application Toolkit where the creators found the biggest challenge to align and ensure the successful transition from standard SIM cards to mini SIM cards. The SIM Application Toolkit is a standard of the ETSI, i.e. the European Telecommunications Standards Institute. It was created to provide the means by which the applications of a SIM card could interact with the mobile phone and the user for the delivery of content based on the browser technology. The problem arose when the network operator required the Java Card, a major component of SIM card which drives the application in the card, to be in 64 kb of memory on the mini SIM cards but with the capacity of 32 kb for the standard SIM cards so that the existing mobile phones could accept the new mini SIM cards in the market too. First of all, the material of the card itself must be in compliance with the ISO standard 7816. A highly specialized plastic with the tolerance of 0.1 mm and the electrical features was adopted for the manufacturing of every type of SIM cards to ensure the reliability, flexibility, and cutting of the cards. In addition, a mini SIM card in terms of memory is quite generous. With a standard of 6 to 7 legs gold flash at a width of 0.25 and a thickness of 0.3 or even 0.5, the electrical circuit on the card material used the latest technology to give the best electrical contact. However, the leg design also allowed the SIM card to be placed in the correct position so that the communication with the mobile phone through the SIM card reader is not obstructed. On the other hand, the users may realize that the SIM cards now have a small opening at the side of the card, not only to help users to know which side is the front facing but also to enable the different types of card to be identified visually and prevent people from accidentally putting a wrong card into a device such as the SIM card would not fit in the micro SIM card slot.

3.2. Mini SIM Card Installation Process

The first step in mini SIM card installation is to make sure that the electronic device you plan to use with your card is switched off. This is followed by identifying the correct SIM card size. Usually, the mini-SIM card is slotted into a separate adapter, which must in turn be placed into a wider “credit card” sized frame before inserting into the electronics. Push in the flap which is holding the SIM card so that it springs out. Gently slide it out and place it into the adapter. Once you have slotted the adapter and SIM card into the frame, it should look like a single object, compatible with the SIM card slot in the electronic device. Nowadays, most “new generation” mini-SIM cards have pop-out “micro SIM” technology – this was something which was introduced aimed at streamlining the process of mini SIM card installation and make the technology smaller. The final stage of mini-SIM card installation is to slot it into the electronic device. Nowadays, most laptops and desktop computers come equipped with mini-SIM slots that are usually located on the side. For a mobile phone, the slot is usually located on the side or beneath the battery, depending on the make and model of the device. One only has to ensure that the contacts on the SIM card are face down; this means that the gold chip must be on the face of the slot. The SIM card should slide into the slot with ease and there is no need to force it. After the mini SIM card has been properly installed, the device can be powered up. If the SIM card has not been used before, one has to go through an initial set and activation process in order to start using mobile telecommunication services. This could involve providing security information and setting up passwords for selected services like voicemail and tariffs. Access to these services would only be provided once the activation is completed.

3.3. Activation and Configuration

After ensuring that the SIM card has been installed in the device and the device has been fully charged, the power button can then be pressed to switch the device on. Once the device has been switched on, a setup wizard or a SIM toolkit application may guide the user through the activation and configuration process. One of the initial steps that the user may be prompted to undertake during the activation process of a mini SIM card is related to setting the date and time on the device. This is an important step as the date and time settings are used to timestamp various events and transactions that may be carried out using the device. For instance, the date and time settings are used to timestamp messages and to record the time at which some applications are being used. Moreover, the small size and portable nature of the device means that the user may move from one location to another and the device may be switched off and on again. In such a case, the date and time settings guide the device to automatically update the time depending on the time zone. This, therefore, ensures that the time is accurate at all times, making it easier for the user to use the device. The activation and configuration process may then prompt the user to connect the device to a Wi-Fi network. The user may be asked to select a Wi-Fi network to connect to and to subsequently enter the password for the selected Wi-Fi network. This step is important as it allows the device to establish an Internet connection which is in turn used to download and install certain updates for the firmware and software of the device. After connecting to the Wi-Fi network and completing the update downloads and installation process, the user may be asked to enter the SIM card unlock code. This is the code that is used to enhance the security of the device and to protect the SIM card against unauthorized use. The SIM card unlock code is unique to the SIM card and will be provided by the carrier company upon successful activation of the personal account.

4. Future Trends and Developments

Nowadays, numerous mobile phone producers have revealed their strategies to present the nano SIM innovation in their devices, in an effort to press the technological improvement much more. The reality that the current Mobile Network Operators keep on buying the production and supply of nano SIM cards shows that they actually believe it will certainly replace the micro SIM and the conventional SIM card, and this is giving the smaller sized variation of the SIM card a great opportunity to become the main type in the future. At the very same time, nano SIM card slots are ending up being a lot more widely readily available in the current smart phone designs and this trend is continuing to grow. It is expected that it will not be long before the mobile phone market is entirely covered by the newer development that is the nano SIM card. A lot of study and development efforts are being bought the assimilation of the SIM card features into the smart phones themselves and embedded SIM development has actually been promoted by the intro of the eUICC requirement. Also, the eSIM runs in harmony with the new remote SIM provisioning capabilities of the eUICC innovation, making it an ideal enabler for customer tools needing high levels of dependability and protection, for example the smart meters that are installed inside our residences. As well as, the embedded SIM technology promises to open doors to brand-new opportunities and usage cases for cordless communications throughout the Internet of Things. Due to the reality that the brand-new eSIM innovation enables a customer to from another location and instantly download and install a mobile operator’s SIM information to a device, whenever it is required, over-the-air, it is expected that both the mobile telephone networks and mobile devices makers will certainly take eSIM modern technology to their hearts and construct it into their product portfolios, gradually but certainly. This is since not just eSIM technology will significantly aid in reducing the prices of providing the traditional SIM card and the inefficiencies in providing them, yet it provides brand-new flexibility and choice to the final consumers as well.

4.1. Nano SIM Cards: The Next Generation

Over the years, mobile phones have become slimmer and more compact. As a result, so have SIM cards. The first SIM card – which stands for ‘subscriber identification module’ – measured 85.60 mm x 53.98 mm x 0.76 mm. The second kind, known as the micro SIM card, was measurably smaller at 15.00 mm x 12.00 mm, while the SIM we use today is even smaller at 12.30 mm x 8.80 mm x 0.67 mm. However, nano SIM cards are now the latest iteration which measure 12.30 mm x 8.80 mm x 0.67 mm – a substantial decrease in size from the original SIM card. Nano SIM cards are still consistent in size and overall design, resembling a small rectangle with slightly smoothed edges, and they still bear the same characteristics of older, larger SIM cards; these being the processor specifications and the connectivity. However, due to rapidly advancing technology and the constant demand for smaller, thinner and lighter devices, it is possible that a new type of SIM card – the eSIM – will supersede even nano SIM cards in the not too distant future.

4.2. eSIM Technology: The Future of SIM Cards

Currently, researchers in the field of mobile communications are looking into ways in which to make the availability of SIM cards and mobile networks more flexible and efficient. In order to address the growing demand for machine-to-machine (M2M) network connections and to provide even greater coverage through the use of mobile networks, new research is being carried out into the integration of SIM card technology with M2M and remote-managed systems. This has resulted in the development of embedded SIM (eSIM) technology, which is being proposed as the next major step in the evolution of digital SIM card design. eSIM technology aims to reduce the physical footprint of a SIM card, improve its flexibility and allow for remote management and synchronization with various different mobile networks. This means that devices with eSIM capability would no longer need to be directly connected to a local network using a physical SIM card; instead, various different eSIM profiles from different mobile network providers could be downloaded and network services could be switched between different providers as required. This capability could bring great advantages to users who have a requirement for digital devices with mobile networking; for example, those that frequently travel between different countries and those that rely on constant mobile network connectivity for GPS location services or data transmission.