Optimising Replication versus Redundancy in Window-aware Opportunistic Routing
2010 (English)Conference paper (Refereed)
In this paper we address the replication versusredundancy optimisation problem for a class of intermittentlyconnectedad hoc networks with the following three characteristics:routing is performed by a store-carry-forward mechanismin an opportunistic manner, replication of custodian messagesis used to increase the delivery ratio, and fragmentationcombined with redundancy in the form of erasure coding isused to deal with large messages in short contact windows.We propose a novel mathematical model in which the meritsof a high replication factor can be compared to a high levelof redundancy in erasure coding. The purpose of the model isto identify the optimised level of replication and redundancyas a function of application-specific parameters like messagesize and time-to-live. Our model builds upon a componentfor message latency distribution that we have borrowed fromearlier works (SprayAndWait) and that has been extended forerasure coding and constrained resources. The model is generaland can be applied in different opportunistic settings using thefollowing approach. First, we derive a set of equations that aredemonstrated to identify the optimal replication and redundancyfactor in a network with constrained resources. Then,the paper includes an extension that provides a tailormadelatency distribution based on history profiling, thus making itapplicable to any protocol that uses replication/redundancy ina similar network. By theoretical analysis and simulations, wedemonstrate that using erasure coding together with replicationoffers an efficient yet flexible tradeoff between resource costand protocol performance.
Place, publisher, year, edition, pages
IEEE , 2010.
communication theory, delay-tolerant communications, opportunistic, erasure coding, performance
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-72599DOI: 10.1109/CTRQ.2010.40ISBN: 978-1-4244-7273-4OAI: oai:DiVA.org:liu-72599DiVA: diva2:460330
The International Conference on Communication Theory, Reliability, and Quality of Service (CTRQ)