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Opportunistic Networking: Congestion, Transfer Ordering and Resilience
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datorteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik. (Communication Research)
2014 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Opportunistic networks are constructed by devices carried by people and vehicles. The devices use short range radio to communicate. Since the network is mobile and often sparse in terms of node contacts, nodes store messages in their buffers, carrying them, and forwarding them upon node encounters. This form of communication leads to a set of challenging issues that we investigate: congestion, transfer ordering, and resilience.

Congestion occurs in opportunistic networks when a node's buffers becomes full. To be able to receive new messages, old messages have to be evicted. We show that buffer eviction strategies based on replication statistics perform better than strategies that evict messages based on the content of the message.

We show that transfer ordering has a significant impact on the dissemination of messages during time limited contacts. We find that transfer strategies satisfying global requests yield a higher delivery ratio but a longer delay for the most requested data compared to satisfying the neighboring node's requests.

Finally, we assess the resilience of opportunistic networks by simulating different types of attacks. Instead of enumerating all possible attack combinations, which would lead to exhaustive evaluations, we introduce a method that use heuristics to approximate the extreme outcomes an attack can have. The method yields a lower and upper bound for the evaluated metric over the different realizations of the attack. We show that some types of attacks are harder to predict the outcome of and other attacks may vary in the impact of the attack due to the properties of the attack, the forwarding protocol, and the mobility pattern.

sted, utgiver, år, opplag, sider
Uppsala: Acta Universitatis Upsaliensis, 2014. , s. 45
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1148
Emneord [en]
Opportunistic Networking, Congestion, Transfer Ordering, Resilience, Testbed, WISENET
HSV kategori
Forskningsprogram
Datavetenskap med inriktning mot datorkommunikation
Identifikatorer
URN: urn:nbn:se:uu:diva-223492ISBN: 978-91-554-8953-3 (tryckt)OAI: oai:DiVA.org:uu-223492DiVA, id: diva2:713179
Disputas
2014-06-09, Room 2446, Polacksbacken, Lägerhyddsvägen 2, Uppsala, 13:15 (engelsk)
Opponent
Veileder
Prosjekter
WISENETTilgjengelig fra: 2014-05-15 Laget: 2014-04-22 Sist oppdatert: 2018-01-11bibliografisk kontrollert
Delarbeid
1. Haggle Testbed: a Testbed for Opportunistic Networks
Åpne denne publikasjonen i ny fane eller vindu >>Haggle Testbed: a Testbed for Opportunistic Networks
2011 (engelsk)Inngår i: In Proceedings of the 7th Swedish National Computer Networking Workshop, 2011Konferansepaper, Publicerat paper (Fagfellevurdert)
Identifikatorer
urn:nbn:se:uu:diva-155530 (URN)
Prosjekter
Haggle
Tilgjengelig fra: 2011-06-23 Laget: 2011-06-23 Sist oppdatert: 2014-06-30
2. Congestion Avoidance in a Data-Centric Opportunistic Network
Åpne denne publikasjonen i ny fane eller vindu >>Congestion Avoidance in a Data-Centric Opportunistic Network
2011 (engelsk)Inngår i: Proceedings of the 2011 ACM SIGCOMM Workshop on Information-Centric Networking (ICN-2011), 2011Konferansepaper, Publicerat paper (Fagfellevurdert)
Identifikatorer
urn:nbn:se:uu:diva-155528 (URN)
Prosjekter
ResumeNet
Tilgjengelig fra: 2011-06-23 Laget: 2011-06-23 Sist oppdatert: 2014-06-30
3. Making the Most of Your Contacts: Transfer Ordering in Data-Centric Opportunistic Networks
Åpne denne publikasjonen i ny fane eller vindu >>Making the Most of Your Contacts: Transfer Ordering in Data-Centric Opportunistic Networks
Vise andre…
2012 (engelsk)Inngår i: Proceedings of the 2012 ACM MobiOpp Workshop on Mobile Opportunistic Networks, Zürich: ACM Press, 2012Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

Opportunistic networks use unpredictable and time-limited con- tacts to disseminate data. Therefore, it is important that protocols transfer useful data when contacts do occur. Specifically, in a data- centric network, nodes benefit from receiving data relevant to their interests. To this end, we study five strategies to select and order the data to be exchanged during a limited contact, and measure their ability to promptly and efficiently deliver highly relevant data.

Our trace-driven experiments on an emulation testbed suggest that nodes benefit in the short-term from ordering data transfers to satisfy local interests. However, this can lead to suboptimal longterm system performance. Restricting sharing based on matching nodes’ interests can lead to segregation of the network, and limit useful dissemination of data. A non-local understanding of other nodes’ interests is necessary to effectively move data across the network. If ordering of transfers for data relevance is not explicitly considered performance is comparable to random, which limits the delivery of individually relevant data. 

sted, utgiver, år, opplag, sider
Zürich: ACM Press, 2012
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-171587 (URN)
Konferanse
ACM MobiOpp
Prosjekter
ResumeNet
Tilgjengelig fra: 2012-03-22 Laget: 2012-03-22 Sist oppdatert: 2014-06-30
4. Resilience and Opportunistic Forwarding: Beyond Average Value Analysis
Åpne denne publikasjonen i ny fane eller vindu >>Resilience and Opportunistic Forwarding: Beyond Average Value Analysis
Vise andre…
2014 (engelsk)Inngår i: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 48, nr SI, s. 111-120Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

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. Moreover, the absence of central coordination and control makes them vulnerable to malicious attacks. In this paper, we study the resilience of popular forwarding protocols to a representative set of challenges to their normal operation. These include jamming locally disturbing message transfer between nodes, hardware/software failures and incompatibility among nodes rendering contact opportunities useless, and free-riding phenomena. We first formulate and promote the metric envelope concept as a tool for assessing the resilience of opportunistic forwarding schemes. Metric envelopes depart from the standard practice of average value analysis and explicitly account for the differentiated challenge impact due to node heterogeneity (device capabilities, mobility) and attackers’ intelligence. We then propose heuristics to generate worst- and best-case challenge realization scenarios and approximate the lower and upper bounds of the metric envelopes. Finally, we demonstrate the methodology in assessing the resilience of three popular forwarding protocols in the presence of the three challenges, and under a comprehensive range of mobility patterns. The metric envelope approach provides better insights into the level of protection path diversity and message replication provide against different challenges, and enables more informed choices in opportunistic forwarding when network resilience becomes important.

HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-222822 (URN)10.1016/j.comcom.2014.04.004 (DOI)000337883200010 ()
Prosjekter
ResumeNet, WISENET
Forskningsfinansiär
EU, FP7, Seventh Framework Programme, FP7-224619
Merknad

Special Issue

Tilgjengelig fra: 2014-04-17 Laget: 2014-04-14 Sist oppdatert: 2017-12-05bibliografisk kontrollert

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