- Ignoring the 3D nature of antenna placement, you need to model the concrete walls properly to get an answer that is semi reliable. All materials have frequency dependent reflection and transmission (attentuation) coefficients. Its pretty easy to extend a toy FDTD sim to include these.
- For the reasons above, inferring 2.4Ghz behaviour from ~1GHz (30cm) signal isn't really a good thing to do (even in a "hand waving" manner).
- When displaying E-fields, you usually want to plot the ||E||^2 averaged over one complete wave cycle -- the nodes shouldn't jump around. If they do, it means the simulation hasn't reached a steady state.
A real antenna won't be an isotropic radiator, either. Got any antenna-pattern plots?
Maybe there are products out there already that allow people to hide their networking hardware in plain sight?
Many of the enterprise APs with integrated antennas are designed for ceiling installation. They often have an antenna that's intended to radiate its best coverage down from the ceiling in a cone.
I'm hoping for precise indoor navigation, Google and Apple are currently working on that. All you'd have to do is walk around with your phone, measuring signal strength and then visualize that.
I'd wager there are _a lot_ more folks that that looking the problem. Its difficult to just use signal strength as this is heavily multi path dependent and time-varying as anything (e.g., moving your phone and hand around) within the environment changes.
There are results in the literature floating around that show some basic success, but nothing at all like the dreams of indoor GPS we're all hoping for. It's a fun problem space, but still in its infancy.
It's not quite true. It assumes that the electric field oscillates with the same phase at every point. Normally the Helmholtz equation is solved assuming that the time dependence is exp(I\omega t), where I is the imaginary unit, and we search for a complex E(x) solution. arg(E(x)) deals with the phase factor, abs(E(x)) is the amplitude. Re( E(x)exp(I\omega t) ) is a solution to the Maxwell equations.