CellAntenna is a leader in solving cellular communications problems inside buildings, vehicles, Emergency Operations Centers, and other structures. We have supplied systems and expertise to over 80,000 customers worldwide. CellAntenna's In-Building Repeater Packages (also referred to as "Distributed Antenna Systems") and custom designed systems bring in cellular phone signals from outside, greatly reducing the the potential of experiencing "dropped calls", and allow cell phone users to use their cell phones even deep inside a building, in basements, parking garages, and other areas. We handle everything cellular. We can accommodate a small home, a large hospital, up to an aircraft carrier. CellAntenna's systems can improve any US cellular provider's signal, including Nextel, Verizon, Alltel, Sprint, ATT, T-Mobile, and others operating under any type of service including AMPS, TDMA, CDMA, GSM, iDEN, GPRS, 3G, and Public Safety. We also supply systems that improve international cellular carriers' signals. CellAntenna has developed an innovative solution to illegal cell phones in prisons. Based on a cellular testing system, the CJAM-CPC can control and eliminate the illegal use of cell phones by inmates in prisons, criminals during the committing of a crime, or ensuring complete cell phone security within a building. Our system can be used for both CDMA and GSM communication, providing both hardware and software interfaces making the CJAM-CPC user friendly. Designed by cellular engineers, the CJAM-CPC solution monitors and interacts with cell phones by way of RF receivers and RF signal generators for both the Reverse and Forward channels. Using an integrated GPS receiver the CJAM-CPC is capable of precisely timed firing of signals and precise synchronization with the GSM and CDMA networks under test. This allows identification of individual phones and in turn, their elimination.