The ability to initiate a phone call on an Android device absent a Subscriber Identity Module (SIM) card hinges on leveraging alternative network connectivity. This involves utilizing Voice over Internet Protocol (VoIP) services or Wi-Fi calling features native to the device and/or carrier. An example includes making a call through a VoIP application, such as Skype or WhatsApp, when connected to a Wi-Fi network on an Android phone lacking a SIM.
This functionality offers considerable benefits, including cost savings by avoiding traditional cellular charges, especially when calling internationally. It also allows for communication in areas with limited or no cellular coverage but with available Wi-Fi. Historically, reliance on SIM cards was absolute for mobile communication; however, technological advancements have provided workarounds, expanding accessibility and flexibility in communication methods.