Typically traditional test system providers take a combination of bench top instruments or instrument specific modules, and they rack them up with the appropriate interconnect cabling and connectors between the instruments and the product. They then add software that makes calls to the functional capabilities embedded in these instruments. This is better known as the “rack-and-stack” approach to test system development. Table 1 lists some examples of traditional instruments, and Figure 1 illustrates an example of a simple rack-and-stack Radio Frequency (RF) test system.