Let’s take GSM/3G as an example and briefly review how a network application works. ZTE Blade S6 (read our review on page supports 3G/4G only on its first SIM slot, and you can’t change the data connection for browsing the web or making video calls. Did it only happen to so that they could avoid getting phone calls from their partner and how can it benefit us as consumers. 3. Better connectivity – Apart from being portable and inexpensive, another benefit of smart phones is that they allow better quality connectivity through Wi-Fi, Bluetooth and AirDrop. SIM’ stands for Subscriber Identity Module and refers to a smart card that securely stores the subscriber identifier and the associated key used to identify and authenticate to a mobile network. Thus all network applications are implemented as Java Card applets and emulate the legacy file-based structure for backward compatibility. By default, when you are using the data connection on one SIM and a phone call comes in to the other it will pause the data connection on the first.

The data connection is where there seems to be a lot of confusion when it comes to dual-SIM phones. Purchasing unlocked phone can be expensive in comparison to locked phones. We can implement the state-of-the-art Voice over Internet Protocol (VoIP) that converts a traditional voice signal in your business phone system into a digital signal that can travel over the Internet. Many large companies have supported the 3G mobile system for this reason. Initial smart cards were based on a file system model, where files (elementary files, EF) and directories (dedicated files, DF) were named with a two-byte identifier. As mentioned previously, mobile devices can include some form of a Secure Element (SE), but a smart card based UICC (usually called just ‘SIM card’) is almost universally present. Of course, not every smart that fits in the SIM slot can be used in a mobile device, so the next question is: what makes a smart card a SIM card?

Cheap smart phones now boast the feature of getting connected with the wi-fi routers and serve the same connectivity speed as the laptop or a computer could do. While the original GSM standard did not make a distinction between the physical smart card and the software required to connect to the mobile network, with the introduction of 3G standards, a clear distinction has been made. You can change these colours and whether or not the phone number is displayed within the SIM Management menu to make it more instantly obvious which is which. When we tried to change the data connection from O2 to Vodafone, it displayed a message suggesting that 3G wasn’t supported by the Vodafone SIM. Which SIM is configured to use the data connection is instantly evident from the navigation bar, with the SIM in slot 1 displayed in blue and the SIM in slot 2 displayed in green.

It is just starting to become mainstream for more and more people to use mobile phones to browse the internet, shop online, communicate with their office or home computer and download programs, applications or ringtones. Numerous people buy high-priced cellphones and have general advances included. This could be bad news for doctors or people who need to be contactable at all hours. Music listeners can have up to 60 hours non stop audio playback or can finish 5 movies of 2 hours each before looking for mains socket. Etisalat is one of two telecommunications network in the United Arab Emirates, and they have some codes that makes the user easily control some certain services such as balance requesting. The user does not have to compromise on the connectivity or the speed part while surfing web from the phone through WLAN. Our last post introduced one of Android 4.3’s more notable security features — improved credential storage, and while there are a few other enhancements worth discussing, this post will slightly change direction. Applets are installed according to GlobalPlatform specifications by authenticating to the Issuer Security Domain (Card Manager) and issuing LOAD and INSTALL commands. Continuing the topic of hardware-backed security, we will now look into how SIMs can be programmed and used to enhance the security of Android applications.

Practically all SIMs used today are based on Java Card technology and implement GlobalPlatform card specifications. Virtually all SIM cards in use today are programmable and thus can be used as a SE. Whereas both SIM slots on some dual-SIM phones are capable of supporting 3G connections (for example, the Elephone P5000 reviewed on page), you can use 3G on only one SIM at a time. There are three main types and sizes of SIM card available, which fit specific devices. So what is a SIM card? Blade S6 also allow you to change the SIM card name. We found that by default the contacts from both SIM cards are stored in the phone book. But how do you facilitate collaboration between members who are weary of it? If it’s you who wants to make a call or send a text, Android has a standard SIM Management menu that lets you specify which SIM should be used for voice calls, video calls, messages and mobile data. If you choose the latter, the next time you want to make a call or send a text, you will be asked which SIM you want to use.