Title: Wireless Infrastructure
Course: Critical Infrastructure: An Overview > Section: Course Content

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Wireless Infrastructure

Wireless is defined by Merriam Webster as, “of or relating to the use of radio waves to send and receive electronic signals” [9].“The wireless component consists primarily of cellular telephone, paging, personal communications services, high-frequency radio, unlicensed wireless, and other commercial and private radio services, including numerous law enforcement, public safety, and land mobile radio systems” [2, p. 20]. Most wireless technology uses radio waves to transfer information.

How It Works

A cell or mobile wireless system uses high frequency radio wave technology in a cellular architecture. The cellular name came from the way the system is designed in order to allow for frequencies to be used numerous times without causing interference. If you were to draw a map of your local cell towers and then you drew an outline around the towers showing the area they covered, you would see that the circles look similar to cells in biology. The center or nucleus of these cells would be the tower itself (even though it may or may not be truly the geometric center). Typically these cells look like hexagons. These cells work together to form a network and in ideal situations the signals from the cells overlap enough that you can move between one cell of coverage to another without your call getting dropped. The networks are made up of cell sites, mobile switching centers, and base switching controllers.

Cell phones, which are basically radios, have tiny transmitters that send out radio signals while powered on. This emitted signal is picked up by the nearest base station (a relay located at the center of a cell) and allows for the receiving of calls. When you make a call your phone transmits a signal to the nearest base station which identifies the number you dialed and assigns it encrypted code [10].

Cell towers both send and receive signals from your call. After the signal reaches the tower it often travels on a land based line (sometimes underground). If the phone you are calling is a land line the call would stay on wirelines until it reached its destination. If you are calling another cell phone, then the call will have to travel to another tower, there it will be transmitted.

Where It Is Used

Many businesses rely on wireless mobile (cell phone services) or business two-way radios for communication between their employees. These also have applications in military and in government settings. In 2013, Pew Research Center announced that 56% of American of adults owned a smartphone and 91% of adults own a cell phone. Pew Research Center also said, “as of June 2012, 35.8% of American homes have become cell only and another 15.9% of people receive all or almost all their calls wirelessly, even though they still have landlines” [10].