Performance Analysis of ZigBee Wireless Networks for AAL through Hybrid Ray Launching and Collaborative Filtering

Table 2

Properties of the most common materials for our 3D ray launching simulations.

Material	Permittivity ()	Conductivity (σ) [S/m]
Air	1	0
Plywood	2.88	0.21
Concrete	5.66	0.142
Brick wall	4.11	0.0364
Glass	6.06	10^−12
Metal	4.5	4 × 10^7
Polycarbonate	3	0.2