Fredrik Bjurefors

Congestion avoidance in a data-centric opportunistic network

In order to achieve data delivery in an opportunistic network, data is replicated when it is transmitted to nodes within communication reach and that are likely to be able to forward it closer to the destination. This replication and the unpredictable contact times due to mobility necessitate buffer management strategies to avoid buffer overflow on nodes. In this paper, we investigate buffer management strategies based on local forwarding statistics and relevance of the data for other nodes. The results obtained on our emulation platform for opportunistic networks show that strategies with a high data refresh rate achieve the most efficient delivery and generate the smallest overhead on our community and mobility scenarios.

Performance of Pastry in a heterogeneous system

We study how Pastry performs in a heterogeneous network environment of varying size. The large traffic overhead for management traffic makes the overlay nonfunctional if it grows too large. This can be circumvented by partitioning the routing tables at the cost of increased path lengths and response times.

Resilience and Opportunistic Forwarding : Beyond Average Value Analysis

Opportunistic networks are systems with highly distributed operation, relying on the altruistic cooperation of highly heterogeneous, and not always software and hardware-compatible, user nodes. Mor ...