With SDR systems, upgrades in communication ability are achieved by adding or changing software in existing agency radios, much as users of home computers expand or improve their computer's functioning with new software while keeping the same computer hardware. Some elements of SDR technology exist in most public safety radios currently being manufactured; however, the full potential of SDR for public-safety communications has yet to be realized. Before this can occur, significant technical, operational, and regulatory challenges must be addressed. The U.S. Justice Department's National Institute of Justice (NIJ), through partnerships and research grants, is working to help resolve these issues and accelerate the progress of SDR technology. The goals of NIJ's efforts with SDR technology are to develop radios that operate on multiple frequency bands and use multiple services, such as two-way radios, cellular, and wireless data. Multifrequency band radios could include software that controls operating parameters, such as frequency, and allows the radio to be reconfigured, as needed. Although these features are present in military radios, they have yet to be included in radios used by public-safety personnel. SDR technology could not only enable agencies with different "home" communication systems to talk with one another when engaged in a cooperative operation; it allows potential cost savings over the life of the radio equipment by enabling agencies to upgrade individual pieces of equipment with new features and communications protocols, upgrade an entire communications system, and add new frequencies as they become available. 1 note