Knowing PONOS, it's not likely that they will name this feature Cat Beacon, the name of this article is just temporary.
Cat Beacon is PONOS's answer to the pirates that should be playing the English, Korean or Taiwanese version instead of BCJP on a different region. This feature was added in update version 6.1 of Nyanko Daisensou. Currently known usage of this feature is to send data to players via their smartphone in a limitedspace. Unlocked after beating Chapter 1 of the Empire of Cats. This feature is not available in the English version.
AIBeacon is a service that make use of smartphone's data miningtechnology. When users approach the installed AIBeacon terminal, their behavior characteristics will be acquired, it's possible to send to those users data such as push notifications and coupons. What Beacon can do is sending data to any devices in range regardless of application. Then receive data in return anon-ly for privacy concern. That is why it used bluetooth, because bluetooth to receive data requires user to be only have bluetooth enabled then confirm data receive. The said user does not need to join the network at all. In Battle Cats case, the player's smartphone must be at Android version 4.3 and above or iOS 7 and above to use this feature. Due to the Beacon's short range, expect more area limited events to come.