In short, both humans and the Tos Civilization currently only use conventional methods such as electromagnetic waves and neutrinos for communication. The research on gravitational waves also counts as a type.
However, gravitational waves can carry very limited information and need to be induced by stimulating a cosmic string. The propagation speed is still just the speed of light, and there's no way to achieve superluminality.
Quantum entanglement can exceed the speed of light, but it cannot transmit any information, as this is dictated by theory and cannot be broken.
Just like the law of conservation of energy, humans have never discovered physical phenomena that violate the conservation of energy or instances where quantum entanglement can transmit information.
