Is there any other way to fly quadcopter without using apm or RC?

currently we are planning for long range wifi, we needed to know how can the gcs can be constantly in touch with copter is that we need to use 4g dongle. We want to use mavlink commands to send messages to the drone instead of using functions provided in apm planner or mission planner. we want to implement the simulation part SITL firmware directly to the drone. IS it possible?