  We consider a time slotted communication system consisting of a base station
(BS) and a user. At each time slot an update packet arrives at the BS with
probability $p$, and the BS successfully transmits the update packet with
probability $q$ over an erasure channel. We assume that the BS has a unit size
buffer where it can store an update packet upon paying a storage cost $c$.
There is a trade-off between the age of information and the storage cost. We
formulate this trade-off as a Markov decision process and find an optimal
switching type storage policy.
