They have developed cellular telephone entry systems during the shift from landline phones to cell phones.
Before they used cellular networks, telephone entry systems used copper wires to connect an entryway’s door station to each resident’s apartment. Installing one of these entry systems meant modifying existing phone lines or purchasing and laying new wiring.
Even today, running wire throughout a building means tearing out walls and rebuilding them again, and those costs add up. What’s more, residents could only answer calls from guests when they were in their properties. As a result, landline phone entry systems caused residents to miss visitors and deliveries.
When cell phone popularity exploded in the 2000s, the landline system quickly became outdated. Intercom providers turned to cellular technology as a better, more efficient alternative to wired landlines. In contrast to landline systems, cell phone-based systems use cellular networks, eliminating the need for wiring.