Proceedings of the 6th International Workshop on Underwater Networks最新文献

{"title":"Low spreading loss in underwater acoustic networks reduces RTS/CTS effectiveness","authors":"J. Partan, J. Kurose, B. Levine, J. Preisig","doi":"10.1145/2076569.2076574","DOIUrl":"https://doi.org/10.1145/2076569.2076574","url":null,"abstract":"The relatively low spreading losses in underwater acoustic channels allows increased interference from distant interferers, which reduces the effectiveness of collision-avoidance MAC protocols. These collisions in turn reduce spatial reuse and network goodput, and increase power consumption. A competing channel effect, however, is the frequency-dependent absorption. The absorption can strongly suppress distant interferers, improving the effectiveness of collision-avoidance protocols. A third channel effect is frequency-dependent ambient noise, which reduces effectiveness for links consisting of widely separated nodes. RTS/CTS effectiveness generally decreases with decreasing acoustic frequency. We present analytic, numerical, and simulated results detailing how each of the major characteristics of the physical channel and physical layer affect the RTS/CTS effectiveness. We find that RTS/CTS effectiveness can drop to between 50%--90% for source and receiver separated by more than about two-thirds of the maximum packet range. The effect depends heavily on the acoustic frequency. We also present as a hypothesis an alternative physically based spreading model that distinguishes between desired signals, which are typically coherently detected via the largest of their multipath arrivals, and interfering signals whose effect on detection performance is related to the total energy in all of their multipath arrivals.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123600886","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}

{"title":"Considerations for the design of an epipelagic biomimetic electrostatic imaging element","authors":"J. Friedman, H. Herman, Newton Truong, M. Srivastava, J. Dong, Dustin Torres","doi":"10.1145/2076569.2076580","DOIUrl":"https://doi.org/10.1145/2076569.2076580","url":null,"abstract":"We discuss the development and design of a Biomimetic Electrostatic Imaging (BEI) element for use in a future multichannel imaging instrument. Inspiration for electrostatic sensing is provided by the diverse species of fish that use passive and induced electric fields for hunting, defense, localization, and communication. Designing an electrostatic sensor is not without its challenges. Hardware filter and amplifier design are analyzed since the high impedance signals require high gain and steps must be taken to minimize noise, maximizing signal to noise ratio.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116688745","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}

{"title":"On the predictability of underwater acoustic communications performance: the KAM11 data set as a case study","authors":"B. Tomasi, J. Preisig, M. Zorzi","doi":"10.1145/2076569.2076570","DOIUrl":"https://doi.org/10.1145/2076569.2076570","url":null,"abstract":"In this paper, we analyze the predictability of the communications performance of an adaptive modulation system for underwater acoustic communications. As a case study, we consider the KAM11 data set, which has been collected off the coast of Kauai Island during July 2011. We measure the signal to noise ratio at the output of the equalizer and we observe slow fluctuations over time intervals of up to six minutes. Based on an analytical model and using the estimated time correlation coefficient of subsequent values of the signal to noise ratio (SNR), we compute the communications performance as a function of the feedback delay for an adaptive modulation system, and we evaluate its predictability. We show that it is possible to know in advance the trend of the performance over intervals of three to four minutes.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115019649","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}

{"title":"Towards underwater video transmission","authors":"L. Vall, D. Sura, M. Stojanovic","doi":"10.1145/2076569.2076573","DOIUrl":"https://doi.org/10.1145/2076569.2076573","url":null,"abstract":"This paper addresses the feasibility of underwater wireless video transmission using an acoustic system, which consists of a video compressor/decompressor and an OFDM modulator/demodulator. This work includes two main parts: the design of an algorithm aimed to compensate for the Doppler effect and the assessment of a set of error resilience tools offered by the MPEG-4 standard. The results of the simulations and in-air experiments demonstrate the performance improvement in terms of visual quality of the received video in cases with motion, as well as the system robustness against channel induced errors.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126288541","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}

{"title":"Aquatic-based cyber-physical systems in the Calcasieu Estuary","authors":"W. Dees, F. Phillips, Paul Bender, Kay Kussmann","doi":"10.1145/2076569.2076590","DOIUrl":"https://doi.org/10.1145/2076569.2076590","url":null,"abstract":"This paper documents the application requirements and basic design for a wireless sensor network for monitoring the marshes, swamps, bayous, and rivers of southwest Louisiana. An entomologist and an environmental scientist who are studying the southwest Louisiana region have provided the application specifications. This has resulted in two related sets of data collection goals: environmental data related to mosquito bionomics, and environmental data related to movement of water and its contents in the Calcasieu Estuary.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116941607","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}

{"title":"Launching denial-of-service jamming attacks in underwater sensor networks","authors":"M. Zuba, Z. Shi, Zheng Peng, Jun-hong Cui","doi":"10.1145/2076569.2076581","DOIUrl":"https://doi.org/10.1145/2076569.2076581","url":null,"abstract":"Recent surges in the development of Underwater Sensor Networks (UWSNs) have lead to a rapid acceptance of this technology in scientific, commercial, and military applications. However, there is limited work on secure communication mechanisms and techniques to protect these networks. Security mechanisms are widely studied in terrestrial networks and various defense mechanisms have been developed as safeguards. Due to the difference in communication mediums and physical environments, the existing solutions for terrestrial networks cannot be directly applied for UWSNs. In this paper, we study the effects of denial-of-service jamming attacks on UWSNs in real-world field tests. We develop our own jammer hardware and signals in order to analyze the characteristics of different jamming attack models on a network. Our tests are performed on existing commercial brand acoustic modems and an OFDM modem prototype. We show that UWSNs can be easily jammed using carefully timed attacks which are energy efficient.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122875458","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}

{"title":"Extendible underwater positioning and communication system for AUVS","authors":"A. Proctor, C. Bradley, E. Gamroth, J. Kennedy","doi":"10.1145/2076569.2076584","DOIUrl":"https://doi.org/10.1145/2076569.2076584","url":null,"abstract":"Rapid changes in the Earth's climate have underscored the importance of increasing our understanding of the world's oceans. More resources are required to chart and maintain newly navigable waters in the far north and to identify new supplies of natural resources. We must increase our capacity to sample the ocean spatially, whether it be to collect data about temperature, chemical composition, ice thickness or bathymetry. Accurate widespread spatial sampling by autonomous underwater vehicles requires accurate navigation and the ability to monitor many vehicles simultaneously from a single deployment platform. Ship time on research vessels is both costly and in short supply; in order to fully utilize the vessels that are available, it will be necessary to multi-task by supporting multiple initiatives simultaneously and having multiple vehicles in the water working at any one time. Facilitating this type of work is the objective of the Extendible Underwater Positioning and Communication System proposed here.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131198637","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}

{"title":"Underwater acoustic communication channel simulation using parabolic equation","authors":"A. Song, Joseph Senne, M. Badiey, Kevin B. Smith","doi":"10.1145/2076569.2076571","DOIUrl":"https://doi.org/10.1145/2076569.2076571","url":null,"abstract":"High frequency acoustic communication (8--50 kHz) has attracted much attention recently. Significant advancements have been achieved in terms of data rates, communication range, and performance. At these high frequencies, various physical processes, including surface waves, subsurface bubbles, and ocean volume fluctuations, can significantly affect the communication channel. The time-varying underwater channel has both deterministic and stochastic features. While there is on-going work, the research community is still lacking adequate models that can provide realistic representations of the dynamic channel in the ocean. Advancements in underwater acoustic communication technology mainly rely on at-sea experiments, which are very costly. A realistic channel model not only can facilitate receiver design, help investigate channel limits, and aid in communication algorithm validation and comparison, it also can provide a basis for network level studies. A communication channel simulator is developed here through the use of parabolic equation modeling of acoustic propagation and scattering. Specifically, the simulator uses the Monterey-Miami Parabolic Equation model (MMPE) augmented with a linear surface model. The linear surface model generates an evolving surface based on theoretical or experimental directional surface spectrum and feed the surface displacement and its derivatives to the acoustic model. The time-varying acoustic field is calculated using successive MMPE runs when the surface evolves. At each single run, the model accounts for surface scattering effects based on the surface input. It also accounts for propagation through the water column and through the sediment based on other environmental measurements such as sound speed profile, bathymetry, and bottom properties. The channel simulator is also calibrated by experimental data obtained in the Pacific ocean in 2008. The surface model simulates a time-evolving surface from the directional surface spectrum obtained by a Waverider buoy in the experiment. Based on the surface input and other environmental measurements, the channel simulator generates realistic time-varying impulse responses. The output agreed well with the acoustic measurements in terms of arrival time structure and intensity profile. Acoustic communication performance comparison between the experimental and simulated data will be also reported in the conference.","PeriodicalId":428974,"journal":{"name":"Proceedings of the 6th International Workshop on Underwater Networks","volume":"4 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130670254","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}