Which statement accurately describes how alarm signaling transmission has evolved?

• A. They have always used cellular networks since inception.
• B. They were once transmitted over telephone lines due to cost effectiveness, but now use radio, Internet, and cellular networks.
• C. They have never used telephone lines.
• D. They are currently transmitted exclusively over fiber optic networks.

Answer: (B)

Alarm signaling transmission has evolved as technology has advanced from relying on existing landline infrastructure to using a mix of faster, more flexible paths. In the past, telephone lines were a practical, cost-effective way to get signals from a monitored site to a central station because they were already widespread. As needs grew for quicker alerts, greater reliability, and broader coverage, new media emerged—radio and cellular networks provide wireless reach, while the Internet enables IP-based signaling and remote monitoring. Today, signaling typically uses a combination of radio, Internet/IP, and cellular paths rather than a single medium, with fiber playing a backbone role but not being the sole method. That’s why the best description is that they were once transmitted over telephone lines due to cost effectiveness, but now use radio, Internet, and cellular networks.