This is also easy.
We know to "search the Torah over and over, for everything is in it". Everything obviously includes all software, firmware, wireless, and technology, which is, was or could be. So we should not be surprised to find that hidden within these strange objects, is some very advanced technology, whose functioning at least we can deduce much about.
Indeed, inside the Tephillin, we do find writing of a prescribed fixed nature, not a dot or comma of which we also know, may be changed. The writings within, are clearly some form of advanced software, probably designed to interface precisely with the hardware - which not uncoincidentaly, is also highly prescribed.
Attached to each of the hardware items are two long cables of an organic nature. We know that the body produces electricity and that voltages develop between different parts of the body. The cables are of an absorptive durable flexible material that will tend to absorb sweat - a form of salt water, or in other words, a conductive medium. The other side is dry and covered with a dark insulating film also organic in nature. We know that batteries stack cells to built up ample voltage, so we should not be surprised to find a complex construction of stacked layers, again in a prescribed layout, at least at one cable end. Hence why we have a redundant setup, but both have long cables. The cables probably also house the antennae or whatever is used - AC on a DC voltage would mean the same conductive layers could be used, but this isn't verified.
So tephillin are actually microcoded mini broadcasters with power cells. You would need to disassemble/decompile the writings within, to understand their purpose.
We do however have some hints to go on.
We may deduce that the Shel Rosh contains RAM, based on the verse that states this one shall be as memory between your eyes. Likewise, the Shel Yad is the main broadcasting hardware ("You shall bind it as a sign - or signal - upon your hand"). We may further deduce from the expression that they shall be as totafot between your eyes, that totafot is some type of VR display with stereoscopic vision (but Ben Zuma states it is a discount voucher for Amazon Prime).
The writings state that the "commands" they contain should be obeyed - clearly this is the invoking script for the rest of the software.
If this happens, the script continues, then correct functioning can be tested by checking a standardised signal is detectable that will be received via other Tephillin, and which only "Israel" can detect ("Hear Oh Israel").