On functional limit theorems for the cumulative times in alternating renewal processes

We provide new proofs for two functional central limit theorems, and prove strong approximations for the cumulative “on” times in alternating renewal processes. The proofs rely on a first-passage-time representation of the cumulative “on” time process. As an application, we establish strong approximations for the queueing process in a single-server fluid queue with “on-off” sources.