The City of Naperville sites appear to be out of service as of 6/2/26, and they have moved to their own 800 MHz P25 trunked system.  It is believed that Aurora will continue to use this system until their new trunked system is up and running. 

Please see the WIKI for more information on this system.
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The OpenSky system will be interoperable with DuPage County's emergency telecommunications network, the State of Illinois' STARCOM 21 digital communication system, and various mutual aid channels for public safety agencies, including police, fire, EMS and emergency management.

OpenSky offers digital voice and packet data communications using a high-performance IP backbone network. OpenSky's high quality digital voice trunking capabilities and packet data communications features directly address the needs of both utility and public safety users, and OpenSky is capable of expanding to meet future requirements. In addition, OpenSky networks are based on the widely-accepted IS-732 protocol to support mobile applications with end-to-end TCP/IP connectivity, simplifying application-to-network integration.