Note When you configure the access point as a DHCP server, it assigns IP addresses to devices on its subnet. The devices communicate with other devices on the subnet but not beyond it. If data needs to be passed beyond the subnet, you must assign a default router. The IP address of the default router should be on the same subnet as the access point configured as the DHCP server.
https://supportforums.cisco.com/document/18871/dhcp-server-configuration-cisco-aironet-1100-and-1200-series-ap
the configuration is same on 1602 AP.
