  In this paper we consider several content delivery problems (broadcast and
multicast, in particular) in some restricted types of distributed systems (e.g.
optical Grids and wireless sensor networks with tree-like topologies). For each
problem we provide efficient algorithmic techniques for computing optimal
content delivery strategies. The techniques we present are offline, which means
that they can be used only when full information is available and the problem
parameters do not fluctuate too much.
