ACM/IEEE International Conference on Mobile Computing and Networking最新文献_第8页

Mobility increases the connectivity of K-hop clustered wireless networks 移动性增加了K-hop集群无线网络的连通性

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2009-09-20 DOI: 10.1145/1614320.1614334

Qingsi Wang, Xinbing Wang, Xiaojun Lin

{"title":"Mobility increases the connectivity of K-hop clustered wireless networks","authors":"Qingsi Wang, Xinbing Wang, Xiaojun Lin","doi":"10.1145/1614320.1614334","DOIUrl":"https://doi.org/10.1145/1614320.1614334","url":null,"abstract":"In this paper we investigate the connectivity for large-scale clustered wireless sensor and ad hoc networks. We study the effect of mobility on the critical transmission range for asymptotic connectivity in k-hop clustered networks, and compare to existing results on non-clustered stationary networks. By introducing k-hop clustering, any packet from a cluster member can reach a cluster head within k hops, and thus the transmission delay is bounded as Θ(1) for any finite k. We first characterize the critical transmission range for connectivity in mobile k-hop clustered networks where all nodes move under either the random walk mobility model with non-trivial velocity or the i.i.d. mobility model. By the term non-trivial velocity, we mean that the velocity of nodes v is Θ(1). We then compare with the critical transmission range for stationary k-hop clustered networks. We also study the transmission power versus delay trade-off and the average energy consumption per flow among different types of networks. We show that random walk mobility with non-trivial velocity increases connectivity in k-hop clustered networks, and thus significantly decreases the energy consumption and improves the power-delay trade-off. The decrease of energy consumption per flow is shown to be Θ(logn/nd}) in clustered networks. These results provide insights on network design and fundamental guidelines on building a large-scale wireless network.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121534871","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}

引用次数: 49

On the critical phase transition time of wireless multi-hop networks with random failures 随机故障下无线多跳网络的临界相变时间

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409965

Fei Xing, Wenye Wang

{"title":"On the critical phase transition time of wireless multi-hop networks with random failures","authors":"Fei Xing, Wenye Wang","doi":"10.1145/1409944.1409965","DOIUrl":"https://doi.org/10.1145/1409944.1409965","url":null,"abstract":"In this paper, we study the critical phase transition time of large-scale wireless multi-hop networks when the network topology experiences a partition due to increasing random node failures. We first define two new metrics, namely the last connection time and first partition time. The former is the last time that the network keeps a majority of surviving nodes connected in a single giant component; while the latter is the first time that the remaining surviving nodes are partitioned into multiple small components. Then we analyze the devolution process in a geometric random graph of n nodes based on percolation-theory connectivity and obtain the sufficient condition under which the graph is percolated. Based on the percolation condition, the last connection time and first partition time are found to be on the same order. Particularly, when the survival function of node lifetime is exponential, they are on the order of log(log n); while if the survival function is Pareto, the order is (log n)1/ρ, where ρ is the shape parameter of Pareto distribution. Finally, simulation results confirm that the last connection time and first partition time serve as the lower and upper bounds of the critical phase transition time, respectively. Further, an interesting result is that the network with heavy-tailed survival functions is no more resilient to random failures than the network with light-tailed ones, in terms of critical phase transition time, if the expected node lifetimes are identical.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"458 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116189633","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}

引用次数: 44

WiMAX relay networks: opportunistic scheduling to exploit multiuser diversity and frequency selectivity WiMAX中继网络:利用多用户分集和频率选择性的机会调度

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409964

S. Deb, V. Mhatre, Venkatesh Ramaiyan

{"title":"WiMAX relay networks: opportunistic scheduling to exploit multiuser diversity and frequency selectivity","authors":"S. Deb, V. Mhatre, Venkatesh Ramaiyan","doi":"10.1145/1409944.1409964","DOIUrl":"https://doi.org/10.1145/1409944.1409964","url":null,"abstract":"We study the problem of scheduling in OFDMA-based relay networks with emphasis on IEEE 802.16j based WiMAX relay networks. In such networks, in addition to a base station, multiple relay stations are used for enhancing the throughput, and/or improving the range of the base station. We solve the problem of MAC scheduling in such networks so as to serve the mobiles in a fair manner while exploiting the multiuser diversity, as well as the frequency selectivity of the wireless channel. The scheduling resources consist of tiles in a two-dimensional scheduling frame with time slots along one axis, and frequency bands or sub-channels along the other axis. The resource allocation problem has to be solved once every scheduling frame which is about 5 - 10 ms long. While the original scheduling problem is computationally complex, we provide an easy-to-compute upper bound on the optimum. We also propose three fast heuristic algorithms that perform close to the optimum (within 99.5%), and outperform other algorithms such as OFDM2A proposed in the past. Through extensive simulation results, we demonstrate the benefits of relaying in throughput enhancement (an improvement in the median throughput of about 25%), and feasibility of range extension (for e.g., 7 relays can be used to extend the cell-radius by 60% but mean throughput reduces by 36%). Our algorithms are easy to implement, and have an average running time of less than 0.05 ms making them appropriate for WiMAX relay networks.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133927914","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}

引用次数: 70

GAnGS: gather, authenticate 'n group securely 帮派:聚集，认证和安全组

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409957

C. Chen, Chung-Wei Chen, C. Kuo, Yan-Hao Lai, Jonathan M. McCune, Ahren Studer, A. Perrig, Bo-Yin Yang, Tzong-Chen Wu

{"title":"GAnGS: gather, authenticate 'n group securely","authors":"C. Chen, Chung-Wei Chen, C. Kuo, Yan-Hao Lai, Jonathan M. McCune, Ahren Studer, A. Perrig, Bo-Yin Yang, Tzong-Chen Wu","doi":"10.1145/1409944.1409957","DOIUrl":"https://doi.org/10.1145/1409944.1409957","url":null,"abstract":"Establishing secure communication among a group of physically collocated people is a challenge. This problem can be reduced to establishing authentic public keys among all the participants - these public keys then serve to establish a shared secret symmetric key for encryption and authentication of messages. Unfortunately, in most real-world settings, public key infrastructures (PKI) are uncommon and distributing a secret in a public space is difficult. Thus, it is a challenge to exchange authentic public keys in a scalable, secure, and easy to use fashion.\u0000 In this paper, we propose GAnGS, a protocol for the secure exchange of authenticated information among a group of people. In contrast to prior work, GAnGS resists Group-in-the-Middle and Sybil attacks by malicious insiders, as well as infiltration attacks by malicious bystanders. GAnGS is designed to be robust to user errors, such as miscounting the number of participants or incorrectly comparing checksums. We have implemented and evaluated GAnGS on Nokia N70 phones. The GAnGS system is viable and achieves a good balance between scalability, security, and ease of use.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114494630","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}

引用次数: 88

Multi-hop mobile wireless network design: implicit cross-layer loss models and performance sensitivities 多跳移动无线网络设计:隐式跨层损耗模型和性能灵敏度

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409945

J. Baras

{"title":"Multi-hop mobile wireless network design: implicit cross-layer loss models and performance sensitivities","authors":"J. Baras","doi":"10.1145/1409944.1409945","DOIUrl":"https://doi.org/10.1145/1409944.1409945","url":null,"abstract":"We describe new methods for multi-hop mobile wireless network design, so as to meet performance specifications. We introduce an implicitly defined approximate loss model that couples the physical, MAC and routing layers' effects. The model provides quantitative statistical relations between the loss parameters that are used to characterize multiuser interference and physical path conditions on the one hand and the traffic rates and types between origin-destination pairs on the other. The model considers effects of hidden nodes, node scheduling algorithms, MAC and PHY layer failures and unsuccessful packet transmission attempts at the MAC layer in arbitrary network topologies where multiple paths share nodes. We consider both contention-based as well as scheduling-based MAC protocols. The new methods are based on implicit loss network models developed using fixed point methods. We describe the application of Automatic Differentiation (AD) to these implicit performance models, and develop a methodology for sensitivity analysis and parameter optimization for wireless protocols. We also introduce new methods that utilize on-line feedback from the PHY layer to simplify the joint MAC and routing protocol design. We provide several examples, with realistic scenarios, that demonstrate the benefits of applying these new methods in an integrated manner. We close with current and future work that extends these methods and algorithms towards a Component-Based design, performance analysis and validation of distributed protocols for mobile wireless networks. We argue that this set of ideas provides a very promising approach to 'clean slate' design for such networks and the resulting hybrid broadband Internet.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114729345","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}

引用次数: 0

Cabernet: vehicular content delivery using WiFi 解百纳:使用WiFi的车载内容传送

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409968

Jakob Eriksson, H. Balakrishnan, S. Madden

{"title":"Cabernet: vehicular content delivery using WiFi","authors":"Jakob Eriksson, H. Balakrishnan, S. Madden","doi":"10.1145/1409944.1409968","DOIUrl":"https://doi.org/10.1145/1409944.1409968","url":null,"abstract":"Cabernet is a system for delivering data to and from moving vehicles using open 802.11 (WiFi) access points encountered opportunistically during travel. Using open WiFi access from the road can be challenging. Network connectivity in Cabernet is both fleeting (access points are typically within range for a few seconds) and intermittent (because the access points do not provide continuous coverage), and suffers from high packet loss rates over the wireless channel. On the positive side, WiFi data transfers, when available, can occur at broadband speeds.\u0000 In this paper, we introduce two new components for improving openWiFi data delivery to moving vehicles: The first, QuickWiFi, is a streamlined client-side process to establish end-to-end connectivity, reducing mean connection time to less than 400 ms, from over 10 seconds when using standard wireless networking software. The second part, CTP, is a transport protocol that distinguishes congestion on the wired portion of the path from losses over the wireless link, resulting in a 2x throughput improvement over TCP. To characterize the amount of open WiFi capacity available to vehicular users, we deployed Cabernet on a fleet of 10 taxis in the Boston area. The long-term average transfer rate achieved was approximately 38 Mbytes/hour per car (86 kbit/s), making Cabernet a viable system for a number of non-interactive applications.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122605821","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}

引用次数: 479

ACES: adaptive clock estimation and synchronization using Kalman filtering 自适应时钟估计和同步使用卡尔曼滤波

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409963

Benjamin R. Hamilton, Xiaoli Ma, Qi Zhao, Jun Xu

引用次数: 95

Relays, base stations, and meshes: enhancing mobile networks with infrastructure 中继、基站和网格:通过基础设施增强移动网络

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409955

N. Banerjee, M. Corner, D. Towsley, B. Levine

{"title":"Relays, base stations, and meshes: enhancing mobile networks with infrastructure","authors":"N. Banerjee, M. Corner, D. Towsley, B. Levine","doi":"10.1145/1409944.1409955","DOIUrl":"https://doi.org/10.1145/1409944.1409955","url":null,"abstract":"Networks composed of mobile nodes inherently suffer from intermittent connections and high delays. Performance can be improved by adding supporting infrastructure, including base stations, meshes, and relays, but the cost-performance trade-offs of different designs is poorly understood. To examine these trade-offs, we have deployed a large-scale vehicular network and three infrastructure enhancement alternatives. The results of these deployments demonstrate some of the advantages of each kind of infrastructure; however, these conclusions can be applied only to other networks of similar characteristics, including size, wireless technologies, and mobility patterns. Thus we complement our deployment with a demonstrably accurate analytical model of large-scale networks in the presence of infrastructure.\u0000 Based on our deployment and analysis, we make several fundamental observations about infrastructure-enhanced mobile networks. First, if the average packet delivery delay in a vehicular deployment can be reduced by a factor of two by adding x base stations, the same reduction requires 2x mesh nodes or 5x relays. Given the high cost of deploying base stations, relays or mesh nodes can be a more cost-effective enhancement. Second, we observe that adding small amount of infrastructure is vastly superior to even a large number of mobile nodes capable of routing to one another, obviating the need for mobile-to-mobile disruption tolerant routing schemes.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128435488","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}

引用次数: 245

Can CSMA/CA networks be made fair? CSMA/CA网络是否公平?

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409972

Ying Jian, Shigang Chen

{"title":"Can CSMA/CA networks be made fair?","authors":"Ying Jian, Shigang Chen","doi":"10.1145/1409944.1409972","DOIUrl":"https://doi.org/10.1145/1409944.1409972","url":null,"abstract":"We demonstrate that CSMA/CA networks, including IEEE 802.11 networks, exhibit severe fairness problem in many scenarios, where some hosts obtain most of the channel's bandwidth while others starve. Most existing solutions require nodes to overhear transmissions made by contending nodes and, based on the overheard information, adjust local rates to achieve fairness among all contending links. Their underlying assumption is that transmissions made by contending nodes can be overheard. However, this assumption holds only when the transmission range is equal to the carrier sensing range, which is not true in reality. As our study reveals, the overhearing-based solutions, as well as several non-overhearing AIMD solutions, cannot achieve MAC-layer fairness in various settings. We propose a new rate control protocol, called PISD (Proportional Increase Synchronized multiplicative Decrease). Without relying on overhearing, it provides fairness in CSMA/CA networks, particularly IEEE 802.11 networks, by using only local information and performing localized operations. It combines several novel rate control mechanisms, including synchronized multiplicative decrease, proportional increase, and background transmission. We prove that PISD converges and achieves (weighted) fairness.","PeriodicalId":378295,"journal":{"name":"ACM/IEEE International Conference on Mobile Computing and Networking","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129121951","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}

引用次数: 52

BreadCrumbs: forecasting mobile connectivity 面包屑:预测移动连接

ACM/IEEE International Conference on Mobile Computing and Networking Pub Date : 2008-09-14 DOI: 10.1145/1409944.1409952

Anthony J. Nicholson, Brian D. Noble

引用次数: 400