I'm sorry for my bad English.
I have an exact 3d model of my office, I need to make augmented reality application using Lenovo Phab 2 Pro in which I can navigate around the office in reality and the application. I need to combine the 3D office model with the data of the Area Description. I'm using Unity. Since the application should work with very large rooms for a long time, it is necessary to use the Area Description to minimize the accumulation of errors.
What I would do is figure out what reference point your Area File starts at (where is point (x=0,y=0,z=0). Then load the Tango Camera Prefab to x=0,y=0,z=0. After this you should load your 3D model of your room and move the 3D model around until it puts your Tango Camera Prefab to the actual starting position where your Area File has (0,0,0). Make sure to have your Relocalization ON in your Unity Settings.