What kind of technology allows you to send digital signals over 100 meters?

I'm looking for a way to send digital signals over ~100 meters. I have researched into technologies such as NFC and bluetooth but their range seems to be limited. I used to own this toy called Eye Link Communicators which would allow me to carry out the types of communications that I am looking for. I would be either satisfied by knowing what Eye Link Communicators uses in the inside or another technology that does something similar.