Suppliers of test equipment for wireless communications face a daunting task: to provide equipment that can exceed the needs of an ever-changing group of operational and performance standards. Cellular test equipment, for example, must not only generate and analyze waveforms used in third-generation (3G) systems, but must now offer the functionality needed to evaluate the infrastructure equipment and mobile handsets used in fourth-generation (4G) cellular networks.

Certainly, this level of performance and flexibility would have required completely different test systems for each cellular generation, perhaps as little as a decade ago. But because test equipment suppliers are adopting the flexibility of modular architectures as well as software-defined-radio (SDR) configurations, they can quickly change the character of their equipment based on a customer's need. What follows is a collection of articles focused on different aspects of 3G and 4G testing, touching on some of the unique features of Long Term Evolution (LTE) and WiMAX systems.