With all devices with <10 meter I do not see the need for mesh.
Also, it sensor are battery powered they are not suitable for routing.
To have a mesh they need a number of mains-powered devices.
I would look at a narrowband radio like RC1740-RC232/RC1780-RC232.
Frequency depend on were final equipment will be operating.
A narrowband radio is less likely to be interfered be other noise in the environment.
We have sold narrowband solution to factory automation system before, were they are concerned with background noise.
Last Update: August 8, 2017