Home network equipment maker D-Link entered the mobile phone market Tuesday, introducing a new line of “V-CLICK” handsets that work with both traditional GSM operators as well as Wi-Fi networks. Users can switch between the technologies with a click of a button.

As wireless hotspots become more ubiquitous, phone manufacturers have turned to building handsets that are able to utilize Internet connectivity for making calls over VoIP. The idea is that such calls are cheaper than traditional cellular calling, especially when dialing internationally. In addition, Wi-Fi coverage could help areas where cellular signals are limited or non-existent.

Theoretically, a user could hop onto a Wi-Fi network when in range and save money, as well as ensure their call won’t drop while indoors. The problem, of course, has been perfecting such a capability, as handing off a call between a cellular and Wi-Fi network has proven quite complicated. T-Mobile, however, has been testing such a service in the northwest United States with positive results.