Proceedings of the 2nd Workshop on Underwater Networks最新文献_第2页

Energy-efficient reliable broadcast in underwater acoustic networks 水声网络中节能可靠的广播

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287823

P. Casari, A. Harris

引用次数: 55

Understanding spatio-temporal uncertainty in medium access with ALOHA protocols 用ALOHA协议理解介质访问的时空不确定性

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287822

A. Syed, W. Ye, J. Heidemann, B. Krishnamachari

{"title":"Understanding spatio-temporal uncertainty in medium access with ALOHA protocols","authors":"A. Syed, W. Ye, J. Heidemann, B. Krishnamachari","doi":"10.1145/1287812.1287822","DOIUrl":"https://doi.org/10.1145/1287812.1287822","url":null,"abstract":"The goal of this paper is understand how location-dependent propagation latency affects medium access control (MAC) by using ALOHA as a case study. MAC protocols in underwater acoustic networks suffer from latency that is five orders-of-magnitude larger than that in radio networks. Existing work on analyzing MAC throughput in RF networks, where the propagation latency is negligible, generally makes assumptions that render propagation latency irrelevant. As a result, only transmit time is considered as being uncertain in contention-based protocols. In this paper, we investigate the spatial dimension of uncertainty that is inherent to varying locations of transmitters, resulting in unequal propagation latency to a receiver. We show through simulation that the benefit of synchronization in slotted ALOHA is completely lost due to such latency. To handle spatial uncertainty, we propose a modification that adds guard bands to transmission slots. We then perform simulation and first-order analysis on this modified MAC to find its optimal operating parameters. Our simulation and analytic results suggest that shorter hops improve throughput.","PeriodicalId":191370,"journal":{"name":"Proceedings of the 2nd Workshop on Underwater Networks","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128342565","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: 172

Effects of the channel on acoustic modem performance in the ocean 通道对海洋声调制解调器性能的影响

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287813

M. Porter, M. Siderius, Katherine Kim, P. Hursky

{"title":"Effects of the channel on acoustic modem performance in the ocean","authors":"M. Porter, M. Siderius, Katherine Kim, P. Hursky","doi":"10.1145/1287812.1287813","DOIUrl":"https://doi.org/10.1145/1287812.1287813","url":null,"abstract":"The U.S. Navy has used underwater acoustic modems for many decades for a variety of applications. As usual, the first interest is simply to get the modem to work and then to work better (increasing ranges, data rates, and robustness). However, as the technology matures, interest turns to performance modeling. This is critical in designing network lay-downs for fixed systems; in dynamically configuring the topology where mobile nodes are in play; and finally in making Smart Modems smarter by enabling them to search the parameter space more efficiently. It is important to note that the ocean environment does have dramatic effects on modem performance. For instance, a developing storm breaks up the acoustic mirror formed by the ocean surface while also generating lots of noise due to breaking waves. Volumetric features such as internal tides cause dramatic refractive changes with equally interesting effects on the scattering function. Interestingly our ability to properly simulate the important effects for acoustic modems has been surprising limited. Coherent modems using equalizers respond on a time scale that is not quite short enough to freeze the ocean surface in a flash of an acoustic strobe pulse, nor long enough to allow one to think of averaged properties. New channel models have been needed to simulate the important effects of a rough, moving, 3D surface. The challenges have expanded further with recent interests in MIMO systems where space-time coherence issues are in play. This talk will provide a perspective on these environmental effects and their incorporation into a channel simulator.","PeriodicalId":191370,"journal":{"name":"Proceedings of the 2nd Workshop on Underwater Networks","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132649825","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: 1

US navy seaweb development 美国海军海上网的发展

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287814

J. Rice

引用次数: 11

A DSP implementation of OFDM acoustic modem 一种DSP实现的OFDM声学调制解调器

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287831

Hai Yan, Shengli Zhou, Z. Shi, Baosheng Li

引用次数: 69

Rate-range for an FH-FSK acoustic modem FH-FSK声学调制解调器的速率范围

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287832

Nathan Parrish, Sumit Roy, W. Fox, P. Arabshahi

引用次数: 10

Frequency reuse underwater: capacity of an acoustic cellular network 水下频率复用:声学蜂窝网络的容量

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 2007-09-14 DOI: 10.1145/1287812.1287818

M. Stojanovic

{"title":"Frequency reuse underwater: capacity of an acoustic cellular network","authors":"M. Stojanovic","doi":"10.1145/1287812.1287818","DOIUrl":"https://doi.org/10.1145/1287812.1287818","url":null,"abstract":"Spatial frequency reuse is considered for large area coverage in bandwidth-limited underwater acoustic networks. The acoustic propagation laws -- namely, the dependence of the path loss on both the distance and the frequency -- lead to a set of constraints that the frequency reuse number N and the cell radius R must satisfy in order to constitute a valid solution for the network topology. For a required signal-to-interference ratio SIR0, and per-user bandwidth W0, the region of admissible solutions (R,N) depends on the desired user density ρ and the available bandwidth B. User capacity is defined as the maximal density ρmax that can be supported within a given bandwidth, and it is derived analytically. Numerical results illustrate the fact that capacity-achieving architectures are characterized by N that grows with ρmax. In a practical system, the bandwidth may be traded off for a smaller reuse number. The capacity is also shown to increase as the operational bandwidth is moved to higher frequencies. Although higher frequencies demand greater transmission power to span the same distance, they also imply a reduction in the cell size, which in turn provides an overall reduction in the transmission power. While complex relationships are involved in system optimization, the analysis presented offers a relatively simple tool for the design of autonomous underwater systems based on cellular network architectures.","PeriodicalId":191370,"journal":{"name":"Proceedings of the 2nd Workshop on Underwater Networks","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127061172","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: 25

Proceedings of the 2nd Workshop on Underwater Networks 第二届水下网络研讨会论文集

Proceedings of the 2nd Workshop on Underwater Networks Pub Date : 1900-01-01 DOI: 10.1145/1287812

引用次数: 0