What a Virtual SIM is

How would you like it if you had to use one computer for accessing your GMail account, another computer for accessing your Facebook account and yet another computer to do your internet banking? Sounds silly, doesn't it? But that's basically what you're doing with your phone.
To use a mobile number, you have a SIM card. To use another number, you have another SIM placed in a separate mobile phone. Dual SIM phones have eased that problem a bit, but what if somebody allowed you to pick up any mobile phone and log-in to the phone with your mobile number, make a call (the billing will be done to your mobile number) and logout of the phone?

Sounds impossible? Futuristic? Well, the future is already here!
In 2008, some brilliant people at Comviva, an Indian company (now owned by Mahindra) and recently, another UK-based company called Movirtu (now acquired by BlackBerry) created the Virtual SIM technology.

What it is

Virtual SIM (I'll be calling it VSIM from now on) is just an imaginary SIM that your mobile phone operator (Airtel, Vodafone, Tata Docomo) will keep in one of their computer databases. Think of it like your Facebook account that's stored on Facebook's database or your GMail account stored in Google's database.

1. To use a mobile number, you first purchase a Virtual SIM mobile number (which will be owned by an operator like Airtel etc. and you would probably also have the option of getting a real SIM card with it). 
2. Then either simply borrow somebody's phone (you can use any ordinary phone for this) or use a phone at a phone-booth, enter your VSIM's USSD code (which looks like this: *101# or *139*1*1234567890#) which is how you 'log-in' to your Virtual mobile number. 
3. The mobile network will identify that the phone is now using a different number, and make a note of it in its VLR (Visitor Location Register) database and it will allow you to make calls using your mobile number and will bill you accordingly. 
4. Type the same USSD code again, and you'll be logged out.

So basically with VSIM, a mobile phone would have a real SIM in it, and an operator like Airtel would be able to allow even a Vodafone VSIM number to login to the Airtel real SIM, by dynamically assigning the Vodafone number to the real Airtel SIM. This technology even keeps track of your missed calls when you're logged out.
With smart-phones, it wouldn't be difficult to keep multiple virtual numbers logged in at the same time. The implementation is dependent on the phone manufacturers and operators.


Another way of looking at VSIM

Yet another company, Implementa provides Virtual SIM technology in a slightly different way:
Here, the real SIM cards are retained by the mobile phone operator at a SIM storage facility and a SIM emulation adapter is placed in the mobile phone instead of the real SIM card. Using the software interface of the mobile phone, you'll be able to assign one of the real SIM's to the SIM emulation adapter in the phone.


Benefits to mobile operators

Market penetration being crucial for companies, VSIM's have the potential to reach people who do not have the money to afford mobile phones. If one among a community of people has a phone, the others can login to it and use it. Their only expense will be their talk-time.
Another market segment is that of companies which allow BYOD and COPE policies. An employee can use their own number for personal calls and log back into the company number to make official calls. Hopefully this would improve the privacy aspect of smart-phone monitoring too, if the phone gets monitored only when it uses the company VSIM.


I love it when innovative ideas hit the market!