As a general rule when deploying you must be out doors away from buildings because there are materials that would interfere with signals. On an occasion I was flying next to an all steel bridge I had to deploy at least 2oo' away because of that electromagnetic interference. When I flew next to & under the structure of steel I noticed a delay in response from controller to drone. Lesson learned....Always look at your environment to determine the best flight plan notice what is surrounding you before you fly