A very smooth way of wireless communication. Put a redstone_torch inside an item_frame on a gold_block (sender) with a button on top or an iron_block (receiver) with a redstone_wire on top. The ItemRotation will decide which one of eight frequencies to use. Comes with a "Mobile Receiver".

Crafting:

R - Redstone Torch

E - Ender Eye

I - Iron Block

Mobile Receiver: (Recipe Book: Feather)

IRI
IEI
 I

Minecraft 1.13

Tier 2/5

Metroite