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