Proceedings of the 5th International Workshop on Underwater Networks最新文献_第2页

D-sync: Doppler-based time synchronization for mobile underwater sensor networks D-sync:基于多普勒的移动水下传感器网络时间同步

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868815

Feng Lu, Diba Mirza, C. Schurgers

{"title":"D-sync: Doppler-based time synchronization for mobile underwater sensor networks","authors":"Feng Lu, Diba Mirza, C. Schurgers","doi":"10.1145/1868812.1868815","DOIUrl":"https://doi.org/10.1145/1868812.1868815","url":null,"abstract":"Time synchronization is an essential service in underwater networks, required for many functionalities such as MAC, sleep-scheduling, localization, and time-stamping of sensor events. However, there exist two fundamental challenges to underwater synchronization, namely, large propagation delays and substantial node mobility during the synchronization process. While existing underwater time sync solutions have been proposed to address these challenges, they rely on heavy signaling, which is undesirable due to high energy costs. In this paper, we introduce a powerful new approach that incorporates physical layer information, namely an estimate of the Doppler shift. Large Doppler shift has been identified as a major challenge to underwater communication, and current systems implement sophisticated solutions to estimate and track such Doppler shift for each data exchange. While an impediment to communication, we will show that the Doppler shift contains highly useful information that can be leveraged to greatly improve time synchronization. Specifically, it provides an indication of the relative motion between nodes. Our new protocol, called D-sync, strategically exploits this feature to address the timing uncertainty due to node mobility. As such, D-sync can handle substantial mobility, without making any assumptions about the underlying motion, and without extensive signaling. Simulation results show that D-sync significantly outperforms existing time synchronization both in terms of accuracy and energy.","PeriodicalId":223476,"journal":{"name":"Proceedings of the 5th International Workshop on Underwater Networks","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122008095","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: 87

Reliable geocasting for underwater acoustic sensor networks 水声传感器网络的可靠地质浇筑

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868830

Baozhi Chen, D. Pompili

引用次数: 1

Network coding to combat packet loss in underwater networks 在水下网络中对抗丢包的网络编码

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868817

M. Chitre, Wee-Seng Soh

引用次数: 8

Contention analysis of MAC protocols that count 竞争分析的MAC协议计数

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868814

A. Syed, J. Heidemann

{"title":"Contention analysis of MAC protocols that count","authors":"A. Syed, J. Heidemann","doi":"10.1145/1868812.1868814","DOIUrl":"https://doi.org/10.1145/1868812.1868814","url":null,"abstract":"The key aspect in the design of any contention-based medium access control (MAC) protocol is the mechanism to measure and resolve simultaneous contention. Generally, terrestrial wireless MACs can only observe success or collision of a contention attempt through carrier sense. An implicit estimate of the number of contenders occurs through repeated observation and changing back-off contention window. Recent work in underwater MAC protocols suggest there it is possible to directly count the number of contenders by exploiting the spatio-temporal uncertainty inherent to high-latency underwater acoustic medium. Prior work has shown how to use counting in underwater MACs, and how to optimize contention windows in radio MACs. In this paper, we quantify bounds to convergence time for MAC protocols employing exact contender counting. We show that perfect counting allows contention to converge quickly, independent of network density, with an asymptotic limit of 3.6 contention rounds on average. We confirm this analysis with simulation of a specific underwater MAC protocol, and suggest the opportunity for the results to generalize for any radio-based MACs that estimate contenders.","PeriodicalId":223476,"journal":{"name":"Proceedings of the 5th International Workshop on Underwater Networks","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127823853","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: 8

Autonomous depth adjustment for underwater sensor networks 水下传感器网络的自主深度调节

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868824

Carrick Detweiler, Marek Doniec, I. Vasilescu, Elizabeth Basha, D. Rus

引用次数: 24

A biomimetic quasi-static electric field physical channel for underwater ocean networks 水下海洋网络仿生准静电场物理通道

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868819

J. Friedman, Dustin Torres, T. Schmid, J. Dong, M. Srivastava

引用次数: 19

Joint channel estimation and data recovery for high-rate underwater acoustic communications with multi-carrier modulation 多载波调制下高速水声通信联合信道估计与数据恢复

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868821

A. Morozov, L. Freitag, J. Preisig

引用次数: 1

Reliable transport and storage protocol with fountain codes for underwater acoustic sensor networks 水声传感器网络的喷泉码可靠传输和存储协议

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868826

Rui Cao, Liuqing Yang

{"title":"Reliable transport and storage protocol with fountain codes for underwater acoustic sensor networks","authors":"Rui Cao, Liuqing Yang","doi":"10.1145/1868812.1868826","DOIUrl":"https://doi.org/10.1145/1868812.1868826","url":null,"abstract":"Due to high energy efficiency and fast data query, data-centric storage (DCS) is a promising technique for underwater acoustic sensor networks (UASN). However, the harsh sea environment poses new challenges to the design of underwater DCS protocols. First, because of long propagation delay and unreliably data links of underwater acoustic communications, long-distance multihop reliable data transport needs to be investigated. Secondly, due to the high node failure probability in the unattended UASNs, data reliability demands better protection. To address these two issues together, a fountain codes based reliable transport and storage (RTS) protocol is proposed in this paper. In the RTS protocol, a distributed fountain coding scheme is designed to facilitate reliable data delivery and multiple acknowledgements are adopted to ensure the control message reliability. In addition, to guarantee uniform data reliability, we devise a distributed storage scheme with concatenated fountain codes. Analyses are provided to reveal the performance of the proposed RTS protocol, which include storage reliability, energy consumption and number of retransmissions.","PeriodicalId":223476,"journal":{"name":"Proceedings of the 5th International Workshop on Underwater Networks","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114365935","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: 22

An OFDM based MAC protocol for underwater acoustic networks 一种基于OFDM的水声网络MAC协议

Proceedings of the 5th International Workshop on Underwater Networks Pub Date : 2010-09-30 DOI: 10.1145/1868812.1868818

Zhong Zhou, S. Le, Jun-hong Cui

{"title":"An OFDM based MAC protocol for underwater acoustic networks","authors":"Zhong Zhou, S. Le, Jun-hong Cui","doi":"10.1145/1868812.1868818","DOIUrl":"https://doi.org/10.1145/1868812.1868818","url":null,"abstract":"In this paper, we investigate OFDM based MAC protocols for underwater acoustic networks. Due to the severe multi-path effects of underwater acoustic channels, the guard time between OFDM blocks becomes significant, which greatly degrades the system rate. In addition, the highly dynamic nature of underwater acoustic channels makes it hard to choose the optimal transmitting power and modulation mode. Furthermore, the bandwidth of most current OFDM modems is only around tens of kHz, which is much less than the available bandwidth in a network with short range communication links. All these challenges make existing OFDM based MAC protocols for designed terrestrial wireless networks unsuitable. In this work, we propose a new MAC protocol called TDM with FDM over OFDM MAC protocol (TFO-MAC), which smoothly couples TDM with FDM/OFDM for the uplink traffic in a cellular like underwater acoustic network. In TFO-MAC, the acoustic channel is divided into multiple sub-channels in frequency via FDM technology, and OFDM modulation is used in every sub-channel. In addition, time is partitioned into slots and every node can use different channels in different slots. Powerful base stations in the network are responsible for the dynamic channel assignment, power optimization and modulation method selection for all nodes in every slot. We formulate the problem as a mixed integer programming problem and propose an efficient greedy algorithm to solve it. Simulation results show that TFO-MAC can achieve high throughput with good fairness.","PeriodicalId":223476,"journal":{"name":"Proceedings of the 5th International Workshop on Underwater Networks","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116156108","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: 20