  The objective of this analysis was to simulate the performance of three
different ad-hoc protocols for disruption-tolerant networking (DTN) - i.e. the
transfer of information through a network of nodes in contexts prone to signal
interruption/signal degradation - and to perform a trade-off analysis that will
yield a recommendation of the best course of action (COA) for a user of a
space-based network to employ. This is important for space-based networks in
particular since transmitting information over long distances - e.g. from
directly from the initial node to the destination node - will result in the
terminal signal being relatively weak, which is problematic in a high noise
(disruption-prone) environment since it will likely result in packet
degradation or loss unless signal power is increased to compensate. Given that
changing signal power for each transmission is impractical when one's network
is located in space, optimization of the signal route is the best means of
ensuring the transmitted signal reaches its destination rapidly and with
maximum fidelity. The recommended COA, as determined at the end of the
analysis, is one that optimizes performance in a fashion that minimizes error
during transmission and transmission time to the greatest extent possible. This
analysis takes into consideration the relative value of transmission time and
transmission error for a user of space-based communication systems (for
instance, a scientific mission - the most likely type of user for a space-based
relay network - would prioritize data integrity much higher than transmission
time since even though a longer transmission time equals greater cost, a lower
level of data integrity could result in the mission's scientific objective
being compromised) and provides a recommendation accordingly.
