The ornamental design for a wireless signaltransmissiondeviceassembly, as shown and described.
FIG. 1 is a front perspective view of a wireless signal transmission device assembly in accordance with my new design, wherein the wireless signal transmission device includes a holder and two wireless signal transmission devices disposed on the holder, and the wireless signal transmission devices may include a wireless access point (WAP), smart speaker, or customer premise equipment (CPE);
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left view thereof;
FIG. 6 is a right view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The portions in broken lines are shown for illustrative purposes only and form no part of the claimed design.