We propose a new framework for providing robust location detection in
emergency response systems, based on the theory of identifying
codes. The key to this approach is to allow sensor coverage to overlap
in such a way that each resolvable position is covered by a unique set
of sensors. In this setting, determining an optimal placement of
sensors is equivalent to constructing an optimal identifying
code. Since constructing optimal identifying codes is generally
NP-complete, we instead propose and analyze a new polynomial-time
algorithm for generating irreducible codes for arbitrary
topologies. We also generalize identifying codes to incorporate
robustness properties that are critically needed in emergency
networks. We develop and analyze a polynomial-time algorithm for
computing robust identifying codes and show these codes to be
irreducible. Through analysis and simulation, we show that our
approach typically requires significantly fewer sensors than existing
proximity-based schemes. Alternatively, for a fixed number of sensors,
our scheme can provide much stronger robustness in the face of sensor
failures or physical damage to the system.