Complex measurements have created a need for complex test solutions. As a result, more and more test equipment is based on a software-defined-radio (SDR) architecture in which different measurement functions can be programmed in software and a wide range of radio standards, for example, can be tested automatically using a single test station. While this approach lacks the simplicity of using test equipment with dedicated controls, it offers tremendous flexibility and the upgradeability required for emerging wireless standards and changing needs in industrial, medical, and military systems.

Of course, the choice of using a "virtual" test system versus one based on dedicated, single-function instruments is very much like choosing to perform measurements on a spectrum analyzer program within a computer rather than using the "real" instrument. Some engineers may prefer having the buttons and knobs in front of them to set center frequency or span, resolution bandwidth, and other measurement parameters, rather than doing the same thing with a computer mouse and display screen. Although both types of measurement solutions are now available, the day may come when the virtual approach replaces dedicated equipment, much in the manner that computers have all but eliminated typewriters.