This paper studies the database failure recovery procedure for cellula
r phone networks as part of the Electronic Industries Association/Tele
communications Industry Association Interim Standard 41 (EIA/TIA IS-41
). Before the location information of the database is recovered, phone
calls may be lost. The restoration process can be sped up by having t
he mobile phones to periodically confirm their existence by radio cont
act with the cellular network. We show that, under some cost assumptio
ns, periodic update interval should be chosen to be approximately equa
l to the call interarrival time, with more frequent updates for more u
nreliable system. We also show that the cost of an optimized system is
relatively small and stable, if the system is even moderately reliabl
e. Finally, if the system is at least moderately reliable, the effects
of call origination rate and the rate at which Location Areas are cro
ssed are rather small, assuming that the periodic update interval was
chosen as stated above. Thus, in such cases, optimization of the size
of the Location Area can be made independent of the optimization of th
e periodic update process.