Opportunistic mobile networks consist of personal mobile devices which are intermittently connected with each other. Data access can be provided to these devices via cooperative caching without support from the cellular network infrastructure, but only limited research has been done on maintaining the freshness of cached data which may be refreshed periodically and is subject to expiration. In this paper, we propose a scheme to efficiently maintain cache freshness. Our basic idea is to let each caching node be only responsible for refreshing a specific set of caching nodes, so as to maintain cache freshness in a distributed and hierarchical manner. Probabilistic replication methods are also proposed to analytically ensure that the freshness requirements of cached data are satisfied. Extensive trace driven simulations show that our scheme significantly improves cache freshness, and hence ensures the validity of data access provided to mobile users.
{"title":"Distributed Maintenance of Cache Freshness in Opportunistic Mobile Networks","authors":"Wei Gao, G. Cao, M. Srivatsa, A. Iyengar","doi":"10.1109/ICDCS.2012.63","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.63","url":null,"abstract":"Opportunistic mobile networks consist of personal mobile devices which are intermittently connected with each other. Data access can be provided to these devices via cooperative caching without support from the cellular network infrastructure, but only limited research has been done on maintaining the freshness of cached data which may be refreshed periodically and is subject to expiration. In this paper, we propose a scheme to efficiently maintain cache freshness. Our basic idea is to let each caching node be only responsible for refreshing a specific set of caching nodes, so as to maintain cache freshness in a distributed and hierarchical manner. Probabilistic replication methods are also proposed to analytically ensure that the freshness requirements of cached data are satisfied. Extensive trace driven simulations show that our scheme significantly improves cache freshness, and hence ensures the validity of data access provided to mobile users.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"13 1","pages":"132-141"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86046702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quickly recovering IP networks from failures is critical to enhancing Internet robustness and availability. Due to their serious impact on network routing, large-scale failures have received increasing attention in recent years. We propose an approach called Reactive Two-phase Rerouting (RTR) for intra-domain routing to quickly recover from large-scale failures with the shortest recovery paths. To recover a failed routing path, RTR first forwards packets around the failure area to collect information on failures. Then, in the second phase, RTR calculates a new shortest path and forwards packets along it through source routing. RTR can deal with large-scale failures associated with areas of any shape and location, and is free of permanent loops. For any failure area, the recovery paths provided by RTR are guaranteed to be the shortest. Extensive simulations based on ISP topologies show that RTR can find the shortest recovery paths for more than 98.6% of failed routing paths with reachable destinations. Compared with prior works, RTR achieves better performance for recoverable failed routing paths and uses much less network resources for irrecoverable failed routing paths.
{"title":"Optimal Recovery from Large-Scale Failures in IP Networks","authors":"Qiang Zheng, G. Cao, T. L. Porta, A. Swami","doi":"10.1109/ICDCS.2012.47","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.47","url":null,"abstract":"Quickly recovering IP networks from failures is critical to enhancing Internet robustness and availability. Due to their serious impact on network routing, large-scale failures have received increasing attention in recent years. We propose an approach called Reactive Two-phase Rerouting (RTR) for intra-domain routing to quickly recover from large-scale failures with the shortest recovery paths. To recover a failed routing path, RTR first forwards packets around the failure area to collect information on failures. Then, in the second phase, RTR calculates a new shortest path and forwards packets along it through source routing. RTR can deal with large-scale failures associated with areas of any shape and location, and is free of permanent loops. For any failure area, the recovery paths provided by RTR are guaranteed to be the shortest. Extensive simulations based on ISP topologies show that RTR can find the shortest recovery paths for more than 98.6% of failed routing paths with reachable destinations. Compared with prior works, RTR achieves better performance for recoverable failed routing paths and uses much less network resources for irrecoverable failed routing paths.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"10 1","pages":"295-304"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82563197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the possibility of cheap identity creation, decentralized online reputation mechanisms are susceptible to sybil attacks. Barter Cast is a reputation mechanism used in the Internet-deployed Tribler file-sharing client. In this paper we study the opportunities for sybil attacks in Barter Cast and we devise a method for making Barter Cast sybil resilient, which is incorporated in a protocol called Sybil Res. Like in Barter Cast, in Sybil Res each peer maintains a local subjective weighted directed graph reflecting data transfer actions in Tribler, from which it computes the reputations of other peers using a flow based algorithm taking the edge weights as flows. In Sybil Res, after an upload action, the uploading peer discounts the weights of the edges on the paths from the down loader to itself. As a consequence, due to the way reputations are computed, the reputation of a peer performing a sybil attack decreases fast. To mitigate the negative impact of edge weight discounting on the reputations of honest peers, after a download action, the downloading peer increases the weights of the edges on the paths from the up loader to itself. We demonstrate that Sybil Res is effective in practice by means of trace-driven simulations using data collected from the Tribler network. The results show that Sybil Res effectively marginalizes attackers while having a minimal effect on the reputations of honest peers.
{"title":"SybilRes: A Sybil-resilient Flow-Based Decentralized Reputation Mechanism","authors":"Rahim Delaviz, N. Andrade, J. Pouwelse, D. Epema","doi":"10.1109/ICDCS.2012.28","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.28","url":null,"abstract":"Due to the possibility of cheap identity creation, decentralized online reputation mechanisms are susceptible to sybil attacks. Barter Cast is a reputation mechanism used in the Internet-deployed Tribler file-sharing client. In this paper we study the opportunities for sybil attacks in Barter Cast and we devise a method for making Barter Cast sybil resilient, which is incorporated in a protocol called Sybil Res. Like in Barter Cast, in Sybil Res each peer maintains a local subjective weighted directed graph reflecting data transfer actions in Tribler, from which it computes the reputations of other peers using a flow based algorithm taking the edge weights as flows. In Sybil Res, after an upload action, the uploading peer discounts the weights of the edges on the paths from the down loader to itself. As a consequence, due to the way reputations are computed, the reputation of a peer performing a sybil attack decreases fast. To mitigate the negative impact of edge weight discounting on the reputations of honest peers, after a download action, the downloading peer increases the weights of the edges on the paths from the up loader to itself. We demonstrate that Sybil Res is effective in practice by means of trace-driven simulations using data collected from the Tribler network. The results show that Sybil Res effectively marginalizes attackers while having a minimal effect on the reputations of honest peers.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"60 1","pages":"203-213"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86065059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Publish/Subscribe (P/S) systems and file sharing applications traditionally share the common goal of disseminating data among large populations of users. Despite this similarity, the former focuses on timely dissemination of small-sized notification messages, while the latter presumes larger types of bulk content with less emphasis on the time needed between release and delivery of data. In this paper, we develop a peer-assisted content dissemination mechanism to bridge this gap by adopting the P/S model. We propose a hybrid two-layer architecture in which P/S brokers act as coordinators and guide their clients with interest in similar content to engage in direct exchange of data blocks in a peer-to-peer and cooperative fashion. Furthermore, we use network coding in order to facilitate data exchange among clients. Our peer-assisted scheme offloads the burden of disseminating huge volumes of data from P/S brokers to subscribers themselves. As an added advantage of our approach, brokers employ strategies that help shape traffic flows in multi-domain network settings. Finally, we have implemented our approach and carried out extensive large-scale experimental evaluation on a cluster with aggregate data transfers of up to 1 TB and involving up to 1000 subscribers. Our results demonstrate good scalability and faster content delivery compared to file sharing protocols such as BitTorrent.
{"title":"Publiy+: A Peer-Assisted Publish/Subscribe Service for Timely Dissemination of Bulk Content","authors":"R. Kazemzadeh, H. Jacobsen","doi":"10.1109/ICDCS.2012.62","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.62","url":null,"abstract":"Publish/Subscribe (P/S) systems and file sharing applications traditionally share the common goal of disseminating data among large populations of users. Despite this similarity, the former focuses on timely dissemination of small-sized notification messages, while the latter presumes larger types of bulk content with less emphasis on the time needed between release and delivery of data. In this paper, we develop a peer-assisted content dissemination mechanism to bridge this gap by adopting the P/S model. We propose a hybrid two-layer architecture in which P/S brokers act as coordinators and guide their clients with interest in similar content to engage in direct exchange of data blocks in a peer-to-peer and cooperative fashion. Furthermore, we use network coding in order to facilitate data exchange among clients. Our peer-assisted scheme offloads the burden of disseminating huge volumes of data from P/S brokers to subscribers themselves. As an added advantage of our approach, brokers employ strategies that help shape traffic flows in multi-domain network settings. Finally, we have implemented our approach and carried out extensive large-scale experimental evaluation on a cluster with aggregate data transfers of up to 1 TB and involving up to 1000 subscribers. Our results demonstrate good scalability and faster content delivery compared to file sharing protocols such as BitTorrent.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"8 1","pages":"345-354"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91530295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mining trajectory data has been gaining significant interest in recent years. However, existing approaches to trajectory clustering are mainly based on density and Euclidean distance measures. We argue that when the utility of spatial clustering of mobile object trajectories is targeted at road network aware location based applications, density and Euclidean distance are no longer the effective measures. This is because traffic flows in a road network and the flow-based density characterization become important factors for finding interesting trajectory clusters of mobile objects travelling in road networks. In this paper, we propose NEAT-a road network aware approach for fast and effective clustering of spatial trajectories of mobile objects travelling in road networks. Our method takes into account the physical constraints of the road network, the network proximity and the traffic flows among consecutive road segments to organize trajectories into spatial clusters. The clusters discovered by NEAT are groups of sub-trajectories which describe both dense and highly continuous traffic flows of mobile objects. We perform extensive experiments with mobility traces generated using different scales of real road network maps. Our experimental results demonstrate that the NEAT approach is highly accurate and runs orders of magnitude faster than existing density-based trajectory clustering approaches.
{"title":"NEAT: Road Network Aware Trajectory Clustering","authors":"Binh Han, Ling Liu, E. Omiecinski","doi":"10.1109/ICDCS.2012.31","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.31","url":null,"abstract":"Mining trajectory data has been gaining significant interest in recent years. However, existing approaches to trajectory clustering are mainly based on density and Euclidean distance measures. We argue that when the utility of spatial clustering of mobile object trajectories is targeted at road network aware location based applications, density and Euclidean distance are no longer the effective measures. This is because traffic flows in a road network and the flow-based density characterization become important factors for finding interesting trajectory clusters of mobile objects travelling in road networks. In this paper, we propose NEAT-a road network aware approach for fast and effective clustering of spatial trajectories of mobile objects travelling in road networks. Our method takes into account the physical constraints of the road network, the network proximity and the traffic flows among consecutive road segments to organize trajectories into spatial clusters. The clusters discovered by NEAT are groups of sub-trajectories which describe both dense and highly continuous traffic flows of mobile objects. We perform extensive experiments with mobility traces generated using different scales of real road network maps. Our experimental results demonstrate that the NEAT approach is highly accurate and runs orders of magnitude faster than existing density-based trajectory clustering approaches.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"10 1","pages":"142-151"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90220444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
According to FCC's ruling for white-space spectrum access, white-space devices are required to query a database to determine the spectrum availability. In this paper, we adopt a game theoretic approach for the database-assisted white-space access point (AP) network design. We first model the channel selection problem among the APs as a distributed AP channel selection game, and design a distributed AP channel selection algorithm that achieves a Nash equilibrium. We then propose a state-based game formulation for the distributed AP association problem of the secondary users by taking the cost of mobility into account. We show that the state-based distributed AP association game has the finite improvement property, and design a distributed AP association algorithm can converge to a state-based Nash equilibrium. Numerical results show that the algorithm is robust to the perturbation by secondary users' dynamical leaving and entering the system.
{"title":"Game Theoretic Analysis of Distributed Spectrum Sharing with Database","authors":"Xu Chen, Jianwei Huang","doi":"10.1109/ICDCS.2012.37","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.37","url":null,"abstract":"According to FCC's ruling for white-space spectrum access, white-space devices are required to query a database to determine the spectrum availability. In this paper, we adopt a game theoretic approach for the database-assisted white-space access point (AP) network design. We first model the channel selection problem among the APs as a distributed AP channel selection game, and design a distributed AP channel selection algorithm that achieves a Nash equilibrium. We then propose a state-based game formulation for the distributed AP association problem of the secondary users by taking the cost of mobility into account. We show that the state-based distributed AP association game has the finite improvement property, and design a distributed AP association algorithm can converge to a state-based Nash equilibrium. Numerical results show that the algorithm is robust to the perturbation by secondary users' dynamical leaving and entering the system.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"195 2 1","pages":"255-264"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78328464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In multi-hop wireless networks where links are prone to be broken or degraded, it is important to guarantee the network connectivity as well as satisfy the performance requirements. Observing the promising features of Multiple-Input Multiple-Output (MIMO) techniques for improving the transmission capacity and reliability, in this paper, we make the very first attempt to deploy MIMO nodes as relays to assist weak links in wireless networks, with the aim of reducing the number of relay nodes and providing performance provisioning. We identify the specific constraints of MIMO relay nodes for assisting weak links, and take advantage of the MIMO ability to flexibly select among different transmission strategies. The constrains and flexibility, however, make the MIMO deployment problem different from conventional single-antenna deployment schemes and much more challenging. Based on the constraints, we formulate the MIMO relay deployment problem, and provide a polynomial-time approximation scheme (PTAS) algorithm, as well as a distributed heuristic algorithm. The performance of the proposed algorithms is evaluated through simulations and demonstrated to be very effective.
{"title":"Enforcing High-Performance Operation of Multi-hop Wireless Networks with MIMO Relays","authors":"Shan Chu, Xin Wang, Minming Li","doi":"10.1109/ICDCS.2012.60","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.60","url":null,"abstract":"In multi-hop wireless networks where links are prone to be broken or degraded, it is important to guarantee the network connectivity as well as satisfy the performance requirements. Observing the promising features of Multiple-Input Multiple-Output (MIMO) techniques for improving the transmission capacity and reliability, in this paper, we make the very first attempt to deploy MIMO nodes as relays to assist weak links in wireless networks, with the aim of reducing the number of relay nodes and providing performance provisioning. We identify the specific constraints of MIMO relay nodes for assisting weak links, and take advantage of the MIMO ability to flexibly select among different transmission strategies. The constrains and flexibility, however, make the MIMO deployment problem different from conventional single-antenna deployment schemes and much more challenging. Based on the constraints, we formulate the MIMO relay deployment problem, and provide a polynomial-time approximation scheme (PTAS) algorithm, as well as a distributed heuristic algorithm. The performance of the proposed algorithms is evaluated through simulations and demonstrated to be very effective.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"1 1","pages":"376-385"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76259878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A brand-new concept about the coverage problem of camera sensor networks, full view coverage, has been proposed recently to judge whether an object's face is guaranteed to be captured. It is specially significant for camera networks since image shot at the frontal viewpoint considerably increases the possibility to recognize the object. In this paper, we investigate the necessary and sufficient conditions to achieve full view coverage under two random deployment schemes, uniform deployment and Poisson deployment. In uniform deployment, we define a centralized parameter - critical sensing area (CSA) - to evaluate the total requirements to reach symptotic full view coverage for all heterogeneous sensors in the network. In Poisson deployment, we develop the probability for a point to be full view covered. Our results reveal that under uniform deployment, whether full view coverage is achieved depends largely on the area of the sensing region, rather than its shape.
{"title":"Achieving Full View Coverage with Randomly-Deployed Heterogeneous Camera Sensors","authors":"Yibo Wu, Xinbing Wang","doi":"10.1109/ICDCS.2012.9","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.9","url":null,"abstract":"A brand-new concept about the coverage problem of camera sensor networks, full view coverage, has been proposed recently to judge whether an object's face is guaranteed to be captured. It is specially significant for camera networks since image shot at the frontal viewpoint considerably increases the possibility to recognize the object. In this paper, we investigate the necessary and sufficient conditions to achieve full view coverage under two random deployment schemes, uniform deployment and Poisson deployment. In uniform deployment, we define a centralized parameter - critical sensing area (CSA) - to evaluate the total requirements to reach symptotic full view coverage for all heterogeneous sensors in the network. In Poisson deployment, we develop the probability for a point to be full view covered. Our results reveal that under uniform deployment, whether full view coverage is achieved depends largely on the area of the sensing region, rather than its shape.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"82 1","pages":"556-565"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72952268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tam N. Vu, A. Baid, Yanyong Zhang, Thu D. Nguyen, J. Fukuyama, R. Martin, D. Raychaudhuri
This paper presents the design and evaluation of a novel distributed shared hosting approach, DMap, for managing dynamic identifier to locator mappings in the global Internet. DMap is the foundation for a fast global name resolution service necessary to enable emerging Internet services such as seamless mobility support, content delivery and cloud computing. Our approach distributes identifier to locator mappings among Autonomous Systems (ASs) by directly applying K>;1 consistent hash functions on the identifier to produce network addresses of the AS gateway routers at which the mapping will be stored. This direct mapping technique leverages the reachability information of the underlying routing mechanism that is already available at the network layer, and achieves low lookup latencies through a single overlay hop without additional maintenance overheads. The proposed DMap technique is described in detail and specific design problems such as address space fragmentation, reducing latency through replication, taking advantage of spatial locality, as well as coping with inconsistent entries are addressed. Evaluation results are presented from a large-scale discrete event simulation of the Internet with ~26,000 ASs using real-world traffic traces from the DIMES repository. The results show that the proposed method evenly balances storage load across the global network while achieving lookup latencies with a mean value of ~50 ms and 95th percentile value of ~100 ms, considered adequate for support of dynamic mobility across the global Internet.
{"title":"DMap: A Shared Hosting Scheme for Dynamic Identifier to Locator Mappings in the Global Internet","authors":"Tam N. Vu, A. Baid, Yanyong Zhang, Thu D. Nguyen, J. Fukuyama, R. Martin, D. Raychaudhuri","doi":"10.1109/ICDCS.2012.50","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.50","url":null,"abstract":"This paper presents the design and evaluation of a novel distributed shared hosting approach, DMap, for managing dynamic identifier to locator mappings in the global Internet. DMap is the foundation for a fast global name resolution service necessary to enable emerging Internet services such as seamless mobility support, content delivery and cloud computing. Our approach distributes identifier to locator mappings among Autonomous Systems (ASs) by directly applying K>;1 consistent hash functions on the identifier to produce network addresses of the AS gateway routers at which the mapping will be stored. This direct mapping technique leverages the reachability information of the underlying routing mechanism that is already available at the network layer, and achieves low lookup latencies through a single overlay hop without additional maintenance overheads. The proposed DMap technique is described in detail and specific design problems such as address space fragmentation, reducing latency through replication, taking advantage of spatial locality, as well as coping with inconsistent entries are addressed. Evaluation results are presented from a large-scale discrete event simulation of the Internet with ~26,000 ASs using real-world traffic traces from the DIMES repository. The results show that the proposed method evenly balances storage load across the global network while achieving lookup latencies with a mean value of ~50 ms and 95th percentile value of ~100 ms, considered adequate for support of dynamic mobility across the global Internet.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"156 1","pages":"698-707"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86320540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study the problem of skeleton extraction for large-scale sensor networks using only connectivity information. Existing solutions for this problem heavily depend on an algorithm that can accurately detect network boundaries. This dependence may seriously affect the effectiveness of skeleton extraction. For example, in low density networks, boundary detection algorithms normally do not work well, potentially leading to an incorrect skeleton being generated. This paper proposes a novel approach, named DIST, to skeleton extraction from incomplete boundaries using the idea of distance transform, a concept in the computer graphics area. The main contribution is a distributed and low-cost algorithm that produces accurate network skeletons without requiring that the boundaries be complete or tight. The algorithm first establishes the network's distance transform - the hop distance of each node to the network's boundaries. Based on this, some critical skeleton nodes are identified. Next, a set of skeleton arcs are generated by controlled flooding; connecting these skeleton arcs then gives us a coarse skeleton. The algorithm finally refines the coarse skeleton by building shortest path trees, followed by a prune phase. The obtained skeletons are robust to boundary noise and shape variations.
{"title":"Skeleton Extraction from Incomplete Boundaries in Sensor Networks Based on Distance Transform","authors":"Wenping Liu, Hongbo Jiang, X. Bai, Guang Tan, Chonggang Wang, Wenyu Liu, Kechao Cai","doi":"10.1109/ICDCS.2012.11","DOIUrl":"https://doi.org/10.1109/ICDCS.2012.11","url":null,"abstract":"We study the problem of skeleton extraction for large-scale sensor networks using only connectivity information. Existing solutions for this problem heavily depend on an algorithm that can accurately detect network boundaries. This dependence may seriously affect the effectiveness of skeleton extraction. For example, in low density networks, boundary detection algorithms normally do not work well, potentially leading to an incorrect skeleton being generated. This paper proposes a novel approach, named DIST, to skeleton extraction from incomplete boundaries using the idea of distance transform, a concept in the computer graphics area. The main contribution is a distributed and low-cost algorithm that produces accurate network skeletons without requiring that the boundaries be complete or tight. The algorithm first establishes the network's distance transform - the hop distance of each node to the network's boundaries. Based on this, some critical skeleton nodes are identified. Next, a set of skeleton arcs are generated by controlled flooding; connecting these skeleton arcs then gives us a coarse skeleton. The algorithm finally refines the coarse skeleton by building shortest path trees, followed by a prune phase. The obtained skeletons are robust to boundary noise and shape variations.","PeriodicalId":6300,"journal":{"name":"2012 IEEE 32nd International Conference on Distributed Computing Systems","volume":"140 1","pages":"42-51"},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81315153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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