For home /building automation, Gateway is necessary. Mesh network is necessary.
For home/building wireless automation, if no gateway and mesh network. It will have some limition. For example, when one use the point to point network. At the point to point communication range, every seems fine when smart phone is at home/building . The following picture show this situation.
When the person changes the position, the long distance device (smart lighting) will be out of control (red color). Thus the mesh network is necessary (blue color).
When the person leaves the house/building, everything is in a mess. the home automation device will be not connected to wireless network.
Thus, for home /building automation, gateway is necessary. mesh network is necessary.
Our wireless IC is support mesh network (Zigbee protocol stack/ IEEE 802.15.4). Our wireless solutions suport with and without gateway solution.
Mesh network shows the following picture.