In that the Zumwalt class has no AN/SPG-62 fire-control radars that are used for terminal guidance for Standard and Evolved Sea-Sparrow Missiles (ESSMs) anti-aircraft engagements, the SPY-3 will generate Interrupted Continuous Wave Illumination (ICWI) rather than the Continuous Wave Illumination of the AN/SPG-62 fire-control radars. Significant software modifications are required to support the ICWI, transmit and receive link messages to the missiles. Standard Missile (SM)-2 IIIA and the ESSM slated for Zumwalt class require modified missile receivers, transmitters, encoders, decoders and a redesigned digital signal processor to work with the ship's system. These modified missiles will not be able to be used on Aegis class ships.