Dual SIM Mobile Phones - Standby Dual-SIM and Active Dual-SIM Phones

A dual SIM mobile phone can hold two SIM cards. Dual SIM phones are of two type standby dual SIM phone and active dual SIM phone. In standby dual SIM phones dual-SIM adapters were made available to use in regular mobile phones to allow them to contain two SIMs, and to switch from one to the other as required. The active dual-SIM phones can natively work with two SIMs, both of which may be active at the same time. There are also some Chinese triple-SIM phones.One can Operate two businesses with two numbers from one Dual Sim phone. With Dual Sim Mobile Phones you can switch off your business number while keeping your private number open for family and friends.
Dual-SIM operation release the burden of carrying two mobile phones. One can use two services without the need to carry two phones at the same time. One SIM for business one SIM for home. For example, the same handset can be used for business and private use with separate numbers and bills; or for travel, with an additional SIM for the country visited.

Standby dual-SIM phones

In this category various types of adapters are available. All of them allow only one SIM to be active, and to receive calls, at any given time; they give various ways of switching from one SIM to the other. In earlier versions phones needed to be switched off to switch from one SIM to another SIM. Later models allow the user to switch SIM cards via a menu or by keying in a numeric code, without switching the phone off.
Some adapters require the two SIM cards to be cut to size, fitted onto a special holder and are inserted into the phone's SIM socket; this can be quite risky, since the user might end up damaging the SIM card in the process. Other adapters don't require cutting or modifying the SIM card. The adapter has two slots for the SIM cards, and a small ribbon cable, which is hooked to a PCB that mimics another SIM card.

Active dual-SIM phones

This category of phones allow both the SIM to be active at the same time and to receive calls from either number at any given time. Normal GSM phones contain a single transceiver; dual-SIM phones must have dual transceivers, and need to display signal strength for both networks. A phone with a single transceiver cannot be converted to simultaneous dual-SIM operation; at most it can be turned into a standby dual-SIM phone with the use of an adapter.
You can buy dual SIM phones at number of location. Some of the dual SIM phones are
DUALSIMTM SLIDER and  DUALSIMTM MINI.