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Cavalcanti de Castro, Marcel
Alternative names
Publications (10 of 24) Show all publications
Cavalcanti de Castro, M. (2011). Enhancing P2P Systems over Wireless Mesh Networks. (Doctoral dissertation). Karlstad: Karlstad University
Open this publication in new window or tab >>Enhancing P2P Systems over Wireless Mesh Networks
2011 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

Due to its ability to deliver scalable and fault-tolerant solutions, applications based on the peer-to-peer (P2P) paradigm are used by millions of users on the internet. Recently, wireless mesh networks (WMNs) have attracted a lot of interest from both academia and industry, because of their potential to provide flexible and alternative broadband wireless internet connectivity. However, due to various reasons such as unstable wireless link characteristics and multi-hop forwarding operation, the performance of current P2P systems is rather low in WMNs.

This dissertation studies the technological challenges involved while deploying P2P systems over WMNs. We study the benefits of location-awareness and resource replication to the P2P overlay while targeting efficient resource lookup in WMNs. We further propose a cross-layer information exchange between the P2P overlay and the WMN in order to reduce resource lookup delay by augmenting the overlay routing table with physical neighborhood and resource lookup history information.

Aiming to achieve throughput maximization and fairness in P2P systems, we model the peer selection problem as a mathematical optimization problem by using a set of mixed integer linear equations. A study of the model reveals the relationship between peer selection, resource replication and channel assignment on the performance of P2P systems over WMNs. We extend the model by formulating the P2P download problem as chunk scheduling problem. As a novelty, we introduce constraints to model the capacity limitations of the network due to the given routing and channel assignment strategy. Based on the analysis of the model, we propose a new peer selection algorithm which incorporates network load information and multi-path routing capability.

By conducting testbed experiments, we evaluate the achievable throughput in multi-channel multi-radio WMNs. We show that the adjacent channel interference (ACI) problem in multi-radio systems can be mitigated, making better use of the available spectrum. Important lessons learned are also outlined in order to design practical channel and channel bandwidth assignment algorithms in multi-channel multi-radio WMNs.

Place, publisher, year, edition, pages
Karlstad: Karlstad University, 2011. p. 157
Series
Karlstad University Studies, ISSN 1403-8099 ; 2011:60
Keywords
peer-to-peer overlay, wireless mesh networks, peer selection, channel assignment, routing, optimization, adjacent channel interference, channel bandwidth adaptation
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-8691 (URN)978-91-7063-398-0 (ISBN)
Public defence
2011-12-20, 1B309, Sjöströmsalen, Universitetgatan 2, Karlstad, 10:15 (English)
Opponent
Supervisors
Available from: 2011-11-29 Created: 2011-10-27 Last updated: 2018-01-12Bibliographically approved
Cavalcanti de Castro, M. & Kassler, A. (2011). On the Interaction Between Peer Selection, Routing and Channel Assignment. Paper presented at The 10th Scandinavian Workshop on Wireless Ad-hoc Networks (Adhoc'11). Paper presented at The 10th Scandinavian Workshop on Wireless Ad-hoc Networks (Adhoc'11).
Open this publication in new window or tab >>On the Interaction Between Peer Selection, Routing and Channel Assignment
2011 (English)Conference paper, Published paper (Other (popular science, discussion, etc.))
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10709 (URN)
Conference
The 10th Scandinavian Workshop on Wireless Ad-hoc Networks (Adhoc'11)
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Castro C, M., Prasad, D. M., Kassler, A. & Avallone, S. (2011). Peer-to-Peer Selection and Channel Assignment for Wireless Mesh Networks. In: : . Paper presented at The 2011 International Workshop on Network Modeling and Analysis (IWNMA-2011)2 jan Bangalore, India (pp. 69-73). IEEE conference proceedings
Open this publication in new window or tab >>Peer-to-Peer Selection and Channel Assignment for Wireless Mesh Networks
2011 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Wireless mesh networks are an emerging paradigm for future broadband wireless access networks, with manyapplication areas ranging from content distribution over community networking and providing backhaul networking for sensor devices. In wireless mesh networks, clients connect to wireless routers which are equipped with one or more wireless cards and relay the packets over the wireless links towards internetgateways or the destination. Peer-to-Peer applications are an important class of applications which contributes nowadays to the majority of internet traffic. Therefore, it is important to provide high capacity in the mesh network to support them. However, the capacity of wireless mesh networks depends on many factors such as network topology and size, traffic volume and pattern, interfaces per node and channel assignment scheme used, modulation schemes, routing approaches, etc. In this paper, we develop an analytical framework which allows to estimate theachievable capacity of a wireless mesh network when peer-to-peer applications download many flows simultaneously. The model is based on the collision domain concept and incorporates various channel assignment, replication and peer selection strategies. We investigate the achievable capacity for various scenarios and study the impact of different parameters such as the number of channels or radios used

Place, publisher, year, edition, pages
IEEE conference proceedings, 2011
Keywords
Wireless Mesh Networks, Peer-to-Peer Networks, Peer Selection, Channel Assignment, Routing
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10214 (URN)
Conference
The 2011 International Workshop on Network Modeling and Analysis (IWNMA-2011)2 jan Bangalore, India
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Cavalcanti de Castro, M., Kassler, A. & Avallone, S. (2010). Measuring the Impact of ACI in Cognitive Multi-Radio Mesh Networks. Paper presented at IEEE 72nd Vehicular Technology Conference (VTC). Paper presented at IEEE 72nd Vehicular Technology Conference (VTC). Ottawa, Canada: IEEE
Open this publication in new window or tab >>Measuring the Impact of ACI in Cognitive Multi-Radio Mesh Networks
2010 (English)Conference paper, Published paper (Refereed)
Abstract

In this paper we address the impact of ACI on dynamic spectrum allocation in multi-radio systems. In particular, we present the benefits of dynamic spectrum allocation by adapting channel bandwidth and distance in order to mitigate ACI in multi-radio mesh networks. Based on our measurement campaign in an indoor mesh testbed, which we extended in order to use adaptive channel width, we evaluate the performance in terms of network throughput. We show that by using channel bandwidth adaptation and antenna separation, the impact of ACI can be significantly reduced. The performed experiments give important insights into ACI in multi-radio cognitive systems which help to develop e.g. better channel assignment algorithms or capacity estimation methods

Place, publisher, year, edition, pages
Ottawa, Canada: IEEE, 2010
Keywords
KAUMesh, Adaptive Channel Width, Adjacent Channel Interference, Wireless Mesh Networks
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-9881 (URN)
Conference
IEEE 72nd Vehicular Technology Conference (VTC)
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Brunström, A., Cavalcanti de Castro, M., Kassler, A., Lavén, A., Dely, P. & Galluccio, L. (2010). NEWCOM++ DR11.3: Final report on the activities and results of WPR11.
Open this publication in new window or tab >>NEWCOM++ DR11.3: Final report on the activities and results of WPR11
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2010 (English)Report (Other academic)
Abstract [en]

This document is the last deliverable of WPR.11 and presents an overview of the final activities carried out within the NEWCOM++ Workpackage WPR.11 during the last 18 months. We provide a description of the most consolidated Joint Research Activities (JRAs) and the main results so far obtained. We also address some considerations on the future activities which are expected to continue at the end of NEWCOM++

Publisher
p. 103
Keywords
Opportunistic networks, localization, analysis, transport, peer-to-peer, connectivity
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10317 (URN)
Projects
NEWCOM (Network of Excellence in Wireless Communication)
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-06-04Bibliographically approved
Cavalcanti de Castro, M., Galluccio, L., Kassler, A., Palazzo, S. & Rametta, C. (2010). On the comparison between performance of DHT-based protocols for opportunistic networks. In: Proceedings of Future Network and MobileSummit 2010: . Paper presented at Future Network and MobileSummit 2010, Florence, Italy. IIMC
Open this publication in new window or tab >>On the comparison between performance of DHT-based protocols for opportunistic networks
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2010 (English)In: Proceedings of Future Network and MobileSummit 2010, IIMC , 2010Conference paper, Published paper (Refereed)
Abstract [en]

Opportunistic networks represent a new frontier for networking research as due to node mobility the network might become disconnected. Such intermittent connectivity imposes challenges to protocol design, especially when information access might require the availability of updated information about resources shared by mobile nodes. An opportunistic network can be seen as a peer-to-peer network where resources should be located in a distributed way. Numerous solutions for P2P resource management have been proposed in the last years. Among the different approaches being considered, Distributed Hash Table (DHT) based schemes offer the advantages of a distributed approach which can be tuned to network scalability. In this paper we consider two well known P2P DHT-based solutions for wireless networks denoted as Bamboo and Georoy, and compare their performance in a multihop wireless scenario. We evaluate scalability and key lookup behavior for different network sizes. The results allow us to gain insights into protocol behavior which allows to select for a given network configuration the appropriate scheme.

Place, publisher, year, edition, pages
IIMC, 2010
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-9773 (URN)978-1-905824-18-2 (ISBN)
Conference
Future Network and MobileSummit 2010, Florence, Italy
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Dely, P., Cavalcanti de Castro, M., Kassler, A., Moldsvor, A. & Soukhakian, S. (2010). Practical Considerations for Channel Assignment in Wireless Mesh Networks. In: GLOBECOM Workshops (GC Wkshps), 2010 IEEE. Paper presented at IEEE Broadband Wireless Access Workshop, held in conjunction with Globecom 2010 (pp. 763-767). IEEE
Open this publication in new window or tab >>Practical Considerations for Channel Assignment in Wireless Mesh Networks
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2010 (English)In: GLOBECOM Workshops (GC Wkshps), 2010 IEEE, IEEE , 2010, p. 763-767Conference paper, Published paper (Refereed)
Abstract [en]

Abstract--- In multi-radio wireless mesh networks (WMNs) several radios can operate within one node simultaneously on different channels. Due to frequency selective fading and varying output powers of WLAN cards the received signal strength on channels in the U-NII band can differ by several dB. Furthermore, power leakage from neighboring channels in the frequency spectrum can cause adjacent channel interference (ACI). Using a IEEE 802.11a testbed, we experimentally evaluate the achievable throughput of a multi-radio mesh network in a string topology under the impact of ACI and channel heterogeneity. Our results show that for low PHY rates the channel separation is a good indicator for throughput. However, for high PHY rates the propagation properties of a specific channel also need to be considered. Based on the results we provide recommendations for designing channel assignment algorithms for IEEE 802.11-based WMNs

Place, publisher, year, edition, pages
IEEE, 2010
Keywords
KAUMesh, Wireless Mesh Networks, Adjacent Channel Interference, Testbed
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-10024 (URN)10.1109/GLOCOMW.2010.5700426 (DOI)978-1-4244-8863-6 (ISBN)
Conference
IEEE Broadband Wireless Access Workshop, held in conjunction with Globecom 2010
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
Brunström, A., Cavalcanti de Castro, M., Karlsson, J., Kassler, A. & Palazzo, S. (2009). DR11.2: Intermediate report on resource management issues and routing/forwarding schemes for opportunistic networks. NEWCOM++
Open this publication in new window or tab >>DR11.2: Intermediate report on resource management issues and routing/forwarding schemes for opportunistic networks
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2009 (English)Report (Refereed)
Place, publisher, year, edition, pages
NEWCOM++, 2009. p. 86
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-11310 (URN)
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-07-23Bibliographically approved
Cavalcanti de Castro, M. (2009). Enabling Multimedia Services over Wireless Multi-Hop Networks. (Licentiate dissertation). Karlstad: Karlstad University
Open this publication in new window or tab >>Enabling Multimedia Services over Wireless Multi-Hop Networks
2009 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

With the constant development of wireless technologies, the usageof wireless devices tends to increase even more in the future.Wireless multi-hop networks (WMNs) have emerged as a keytechnology to numerous potential scenarios, ranging from disasterrecovery to wireless broadband internet access. The distributedarchitecture of WMNs enables nodes to cooperatively relay othernode's packets. Because of their advantages over other wirelessnetworks, WMNs are undergoing rapid progress and inspiringnumerous applications. However, many technical issues still existin this field. In this thesis we investigate how Voice over IP(VoIP) and peer-to-peer (P2P) application are influenced bywireless multi-hop network characteristics and how to optimizethem in order to provide scalable communication.We first consider the deployment of VoIP service in wirelessmulti-hop networks, by using the Session Initiation Protocol (SIP)architecture. Our investigation shows that the centralized SIParchitecture imposes several challenges when deployed in thedecentralized wireless multi-hop environment. We find that VoIPquality metrics are severely degraded as the traffic and number ofmultiple hops to the gateway increase. In the context ofscalability, we further propose four alternative approaches whichavoid current limitations.In the second part of this thesis we tackle the network capacityproblem while providing scalable VoIP service over wirelessmulti-hop networks. The performance evaluation shows the influenceof intra and inter-flow interference in channel utilization, whichdirect impacts the VoIP capacity. In order to avoid the small VoIPpacket overhead, we propose a new adaptive hop-by-hop packetaggregation scheme based on wireless link characteristics. Ourperformance evaluation shows that the proposed scheme can increasethe VoIP capacity by a two-fold gain.The study of peer-to-peer applicability over wireless multi-hopnetworks is another important contribution. A resource lookupapplication is realized through structured P2P overlay. We showthat due to several reasons, such as characteristics of wirelesslinks, multi-hop forwarding operation, and structured P2Pmanagement traffic aggressiveness the performance of traditionalP2P applications is rather low in wireless multi-hop environments.Therefore, we suggested that a trade-off between the P2P lookupefficiency and the P2P management traffic overhead can be achievedwhile maintaining the overlay network consistency in wirelessmulti-hop networks.

Place, publisher, year, edition, pages
Karlstad: Karlstad University, 2009. p. 98
Series
Karlstad University Studies, ISSN 1403-8099 ; 2009:24
Keywords
Wireless Multi-hop Networks, Mobile Ad-hoc Networks, Wireless Mesh Networks, Voice over IP, Session Initiation Protocol, Peer-to-Peer Overlay Networks
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-3980 (URN)978-91-7063-247-1 (ISBN)
Presentation
2009-06-01, Karlstad University, 00:00 (English)
Opponent
Supervisors
Available from: 2009-05-26 Created: 2009-04-14 Last updated: 2018-01-13Bibliographically approved
Cavalcanti de Castro, M., Kassler, A., Kliot, G., Friedman, R., Kummer, R., Kropf, P. & Felber, P. (2009). Minimizing DHT Routing Stretch in MANETs. In: : . Paper presented at 9th Scandinavian Workshop on Wireless Adhoc Networks (Adhoc'09).
Open this publication in new window or tab >>Minimizing DHT Routing Stretch in MANETs
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2009 (English)Conference paper, Published paper (Refereed)
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-11047 (URN)
Conference
9th Scandinavian Workshop on Wireless Adhoc Networks (Adhoc'09)
Available from: 2012-02-08 Created: 2012-02-08 Last updated: 2018-01-12Bibliographically approved
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