Can You Hear Me Now?

In the first half of the 20th Century, rural phone companies were busily wiring vast, sparsely-populated territories. They started by running wires along highways, promising farmers whose property they passed that they might have lines run to their home within a few years. Some of the more impatient farmers tapped into the phone company’s highway trunk lines and connected phones over the barbed wire that ran along their property lines. Today, the availability of wired service to some remote locations can still be problematic, but at the same time wired service is becoming less necessary. Instead, service is increasing coming from the roughly 200,000 cellular towers in the U.S., each potentially serving hundreds of square miles and providing service to heavily and lightly populated areas alike.

To say that the public has embraced cellular service would be an understatement. The number of users who have dispensed with wired phone service entirely is rapidly catching up with the number still using landlines. Most of that usage is voice calling and text messaging, but there is another potentially huge application for the wireless service. As machine-to-machine (M2M) applications multiply, urban areas offer easy connectivity over both copper and fiber. The same can’t be said of remote or undeveloped locations, though the need for M2M connectivity may be just as high. Fortunately, cellular service is an ideal way to fill the gap.

We’ve all seen Verizon’s old “Can you hear me now?” TV ads. The good news for M2M is that cellular signals reach areas that have no copper or fiber infrastructure. The better news is that data can be sent over cellular links even where the other party can’t hear you. The reason is that data sent via cellular SMS (short message service) uses the cellular signaling channel, which is always there alongside the voice channel but which requires far less signal strength than the voice channel. In other words, sensors in farm fields, construction sites, vacation homes, and other unwired locations can send messages and data just as readily as they could in the heart of the city. And unlike wired or Wi-Fi-based devices, cellular ones are more portable and can be much easier to set up, but that’s a discussion for another blog entry.