Are you on the move all the time, traveling from one country to the other? Do you want to divide your work calls from private ones and still have the same set of application available on your phone? Or you just wish to have two separated phone numbers and lines active at the same time? If your answer to one of these questions is YES, then you are a person who needs a dual-SIM phone. What is a dual-SIM phone? The answer is simple: this is a regular phone with two SIM card slots where you can place two different SIM cards. This option is available on a lot of smartphones and can even find it on top flagship models. It is quite interesting that there are two types of dual-SIM phones: - An active dual-SIM phone – such device supports two active SIM cards connected to a network at the same time. This means that you can receive calls, send SMS and exchange data from both cards simultaneously. - A standby dual-SIM phone – these phones also have two SIM card slots, but they can’t support them both at the same time. You need to switch cards (automatically) to be able to use one of them. [caption id="attachment_8129" align="aligncenter" width="300"] Dual-SIM HTC phone[/caption] Both types of smartphones are available for you and it is up to you and your requirements to choose the type that suits you best. Origins of dual-SIM phones First dual-SIM phone was Benefon Twin. It was made in 2000, by Benefon (today TwigComTwigCom) company from Finland. This phone looked very much like old Nokia models. It had moderated success, but the concept presented with this phone was yet to come. [caption id="attachment_8130" align="aligncenter" width="300"] Benefon Twin - first dual-SIM phone[/caption] A few years later, dual-SIM phones made a breakthrough in developing countries. China, Philippines, Pakistan and other Asian countries were markets where low budget dual-SIM models were blooming. India is still the biggest market for such models. In the last two years the situation is quite different – dual-SIM phones are widespread and popular worldwide. "The big guys" started adding this feature to their top models, so now you can have a first class phone with this handy add-on. When can I use dual-SIM phones? You can use them all the time, but there are few major cases when you can highly benefit from this type of phones: - When traveling – roaming services can be quite expensive, especially if you travel a lot and change countries frequently. A local SIM card added to your regular phone number can be a solution for decreasing roaming expenses. You can use your number to be available for friends, family, and clients. Mix it with a number from the local network to get access to cheaper data package and to make it easier for you to run local calls. This benefit is fading away with numerous IM and VoIP apps, but it is still highly valued in countries where Wi-Fi coverage is poor. In such places, you can still rely on good old GSM network. - When using business and private phone number – if you need to have two different phone numbers, and you hate to carry around two phones, the dual-SIM smartphone is an excellent solution. You can separate your work from your personal calls and choose when to take them. On top of that, you wouldn't have to worry about syncing data and application set between your two phones anymore. Everything will be packed up on one device, available to you all the time. [caption id="attachment_8134" align="aligncenter" width="300"] Sony Xperia Z3 dual-SIM[/caption] - When juggling between services – are you using a postpaid package and wish to use benefits of some prepaid offers that are available occasionally? Or you just want to have two different networks available because you wish to make sure that you can be available all the time? Again, the dual-SIM phone can help you. You can use the other SIM card to exploit seasonal offers for prepaid users, or to have the network coverage in areas where you can’t rely on one network only. Bottom Line Someone might say: “I don’t do these things, so why on earth would I need a dual-SIM phone?” Well, if this is the case, you probably don’t need one. Such phones are not for everyone. Dual-SIM phones are for people who are on the move, who don’t want to have two phones to carry around, and who want to take all the advantages that their GSM provider is offering. Now, it’s your turn! Tell us do you use dual-SIM smartphones? How do you use them? What is the biggest benefit that you have from such a device? We are looking forward to your comments! Image source: Anzaq, Mobileaks, Softpedia, SonyMobile.