In this paper, we introduce the Shared Wireless Infostation Model (SWIM), which extends the Infostation model by incorporating information replication, storage, and diffusion into a mobile ad hoc network architecture with intermittent connectivity. SWIM is able to reduce the delay of packet delivery at the expense of increased storage at the network nodes. Furthermore, SWIM improves the overall capacity–delay tradeoff by only moderately increasing the storage requirements. This tradeoff is examined here in the context of a practical application—acquisition of telemetry data from radio-tagged whales. To reduce the storage requirements, without affecting the network delay, we propose and study a number of schemes for deletion of obsolete information from the network nodes. In particular, through the use of Markov chains, we compare the performance of five such storage deletion schemes, which, by increasing the computational complexity of the routing algorithm, mitigate the storage requirements. The results of our study will allow a network designer to implement such a system and to tune its performance in a delay-tolerant environment with intermittent connectivity, as to ensure with some chosen level of confidence that the information is successfully carried through the mobile network and delivered within some time period.

Wireless and mobile network technologies often impose severe resource limitations, resulting in poor and often unsatisfactory performance of the commonly used wire-less networking protocols. For instance, power and memory/storage constraints of miniaturized network nodes reduce the throughput and increase the network latency. Through various approaches and technological advances, researchers at-tempt to compensate somehow for such hardware limitations. However, this is not always necessary. Sometimes, the required performance of such networks does not need to adhere to the level of services that would be required for performance-critical applications. For example, for some applications of sensor networks, min-imal latency is not a critical factor and it could be traded off for a more limited resource, such as energy or throughput. Thus, to reduce the energy expenditure, the transmission range of such sensor nodes would be quite short, leading to net-work topologies in which the average number of neighbors of the network nodes is very small. If the sensor nodes are mobile, then most of the time a node has no neighbors; only infrequently another node migrates into its neighborhood. This