Best Global Sim Card

The Best Global Sim Card (Subscriber Identity Module) is a removable smart card used in mobile phones and HSDPA or HSUPA modems that connect to the USB port. SIM cards securely store the service subscriber key used to identify themselves to the network so that you can change from one mobile phone device to another by simply changing the card.

The SIM card usage is mandatory in GSM networks. Its equivalent to the UMTS USIM and UICC (short for Universal Integrated Circuit Card), most popular being the RUIM (Removable User Identify Module) in CDMA phones.

SIM cards are available in four sizes. The first is similar to a credit card (85.60 × 53.98 × 0.76 mm). The second and more popular measures 25 × 15 × 0.76 mm. The third, known as micro-SIM has dimensions of 15 × 12 × 0.76 mm and the last and most recent, the nano-SIM, measuring 12.3 × 8.8 × 0.7 mm, 40% smaller than a micro-SIM and obviously entails a reduction in size that can be used in very thin terminals.

The specifications for SIM cards are GSM 11.11: Specification of the SIM-ME interface. GSM 11.14: Specification of the SIM Application Toolkit (‘SIM Application Tools’) for the SIM-ME interface.

The last known device that uses micro-SIM card is the Apple iPad in its different versions of 3G technology. Likewise, the iPhone 4 and 4S version uses the same type of SIM as well as the nokia n9.

Lok8u and T-Mobile announced at the International CES 2010 in Las Vegas would be the first to bring the Best Global Sim Card card technology Micro Third-Form-Factor (3FF) to devices (M2M / Machine to Machine) with a line of GPS devices.

Although the iPad was put on sale to be used with any carrier in countries like Mexico, one still need to get a micro-SIM. Therefore, anyone who wishes to use an iPad with 3G technology would need to hire a data plan with a mobile phone operator that offers micro-SIMs. It is however possible physically to modify and adapt one SIM so it can be used on the iPad or on the iPhone 4.

Global SIM cards store network-specific information used to authenticate and identify subscribers, the most important of the ICC-ID, IMSI, Authentication Key (Ki) and local area identification (LAI). The SIM card also stores other operator-specific data such as the SMSC number (central short message service), the service provider name (SPN), the dialing service numbers (SDN) and applications of value added services (VAS). Their descriptions are available in the GSM specification.