Need help on usb transmitter and receiver for Home Light Switch

I am a IT Student and I was thinking to build a USB transmitter for smartphone and receiver switch for light switch for my project, the USB transmitter that connect to smartphone should have the abilities that send the signal with certain range of frequencies to ensure that there is interruption on controlling 2 or more receiver light switches. But i am new to this kind of thing so i don't really have any idea where i should start and look into. And so i hope some expert here can guide me on what i can do to make it. Thanks.

Hmmm...

Making your own transmitter, that can be connected through USB Port of Smart Phone (Really Tough task and extremely Complicated for me).

One approach i can advice you is that, you can use Bluetooth Module of Your Smart Phone as Transmitter, and a separate bluetooth module (like HC05) to receive data from Smart Phone and then based on the packet, control the home lights.

Thanks for the reply, i also thought of using Bluetooth as well, but what if user are using the bluetooth for tethering for the network while they want to control the home light? it cant be done isn't? Therefore i come up with the custom transmitter for it. As you mention it is a tough task and extreme complicated but it still can be done right? Today i went to find my supervisor and he ask me to look into digital data processing, is that what make the transmitter extreme complicated and tough part?