Have you noticed that radio transmission towers have lately become more ... well, more interesting?
Before I go further, I had better define a couple of terms. Those tall skinny things supported by guy wires with their regulation faa blinking red lights are not radio antennas. Technically, they are towers. The antenna is just the thing that sits on a tower. Sometimes an antenna sits on the very top; sometimes they are hung on the side. Antennas come in all shapes and sizes. They may be long and slender, they may be spherical or oblong, they may be boxy, or they may be flat.
It’s the antenna’s job to actually transmit and receive radio signals — usually from another antenna far away. The only purpose of the tower is to hoist the antenna into the air to make it more effective.
And lately, it’s the antennas that are making the towers interesting.
Long ago, transmission towers were primarily the domain of commercial radio and television stations. They were impressive; tall and skinny. Well, that was about it. The taller they were, the skinnier they appeared to be. Straight up. About as aesthetic as a pencil lead.
A few years ago, more and more of them started sprouting on the landscape. And these newcomers were different. They had character.
Suddenly, the tops of the towers sprouted wings. Instead of one boring antenna on top, just about every imaginable antenna could be found. Many times, several different types were on the same tower. They jutted from the sides, they sprang from the top, they ringed the midsection.
The thing that made the difference, of course, was the sudden ubiquity of mobile telephones. Now that there are millions of wireless devices roaming around out there, thousands of new transmission towers are required to communicate with them.
Wireless phones have different transmission needs than a regular commercial radio. For one thing, the communication is two-way, unlike your car radio. It’s also full-duplex — which means, unlike a cb radio, the phone can send and receive at the same time.
And other “housekeeping” transmissions have to occur, which you may never be aware of. These are telemetry signals that help the network keep track of where the phones are and whether or not they are turned on and available to receive a call. They also tell a phone when to ring.
And mobile telephones are only part of the wireless communication revolution. All types of wireless devices demand similar communications networks. Blackberries, gps devices, satellite radio signal repeaters; even the computer that I’m typing this article on is plugged into a virtual wireless network and is in constant communication with a tower down the street from my house.
Of course, such complex communications require complex antennas. And in the process of building them, the communications companies inadvertently gave us new works of art. To make it even better, many of them have banded together to put multiple communications systems on one tower. The same structure may contain antennas belonging to Sprint, Verizon, Cingular, and a couple of other local carriers. Each antenna adds its own special flavor to the total picture that makes every transmission tower unique in its own way. And that makes it unique art — high in the rural sky.
The next time you’re zooming down the interstate, look up. There are some really neat high-tech patterns of wires, steel, and fiberglass up there, ready for your viewing pleasure. After you have enjoyed it, don’t forget to thank your wireless provider for the show.