  We show how to efficiently exploit decoherence free subspaces (DFSs), which
are immune to collective noise, for realizing quantum repeaters with long lived
quantum memories. Our setup consists of an assembly of simple modules and we
show how to implement them in systems of cold, neutral atoms in arrays of
dipole traps. We develop methods for realizing robust gate operations on qubits
encoded in a DFS using collisional interactions between the atoms. We also give
a detailed analysis of the performance and stability of all required gate
operations and emphasize that all modules can be realized with current or near
future experimental technology.
