Dream Language, Dream Linguistics
Dream linguistics is the system utilized by The Circle which began as an exchange of correspondence with entities originating in the star system of Scorpio at the beginning of the 21st century.
Works such as Bram Stokers Jewel of the Seven Stars and Kenneth Grants The Stellar Lode, included in his collection of short stories The Other Child are both examples of the utilization of dream control.
Also consider reading Doris Lessings Shikasta and the Sirian Experiments. These works address both physical and mental travel and communication between species of diverse planetary worlds.
More on Dream Linguistics
Qlippoth An Alternative View
The Sphinx Dreams Her Incarnations