Others have pointed out that signal beacons have certainly been used by many European cultures long before Tolkien however none have explicitly mentioned what I believe is the closest thing to have been used within England to how the beacons function in LOTR.

During the mid-late part of the Anglo-Saxon period, under the reign of Alfred the Great and his descendents, in order to combat the constant Viking raids a series of burhs were constructed. The burhs were built in a network roughly 1 days march from each other with each burh connecting to atleast 2 other burhs. In the event of a Viking raid the nearest burh would light a signal beacon. All connecting burhs who saw the beacon would then march to the burh which called for aid.

[Relevant article][1].


  [1]: https://www.ucl.ac.uk/early-medieval-atlas/news/2016/aug/lighting-anglo-saxon-beacons