UNDERWATER WIRELESS COMMUNICATIONS …

1 Xi ZhangJun-Hong CuiSantanu DasMario Gerlahe Earth is a water planet, two-thirds of which is cov-ered by water. With the rapid developments in tech-nology, UNDERWATER COMMUNICATIONS has become a fastgrowing field, with broad applications in commercial andmilitary water based systems. The need for underwaterwireless COMMUNICATIONS exists in applications such asremote control in the off-shore oil industry, pollution mon-itoring in environmental systems, collection of scientificdata from ocean-bottom stations, disaster detection andearly warning, national security and defense (intrusiondetection and UNDERWATER surveillance), as well as newresource discovery.

2 Thus, the research of new underwaterwireless communication techniques has played the mostimportant role in the exploration of oceans and otheraquatic environments. In contrast with terrestrial wirelessradio COMMUNICATIONS , the communication channels inunderwater WIRELESS networks can be seriously affected bythe marine environment, by noise, and by limited band-width and power resources, and by the harsh underwaterambient conditions. Hence, the UNDERWATER communica-tion channel often exhibits severe attenuation, multipatheffect, frequency dispersion, and constrained bandwidthand power resources, etc.

3 , which turn the UNDERWATER com-munication channel into one of the most complex andharsh WIRELESS channels in nature. When facing theseunique conditions in diverse UNDERWATER applications,many new challenges, which were not encountered in ter-restrial WIRELESS COMMUNICATIONS , are emerging in under-water acoustic, optical, and RF COMMUNICATIONS for futureunderwater WIRELESS networks. Of these challenges, acous-tic and optical are the most compelling, and somewhatcomplementary, owing to the potential for longer rangeand high bandwidth networked COMMUNICATIONS in size-and power-constrained modems and unmanned systems.

4 Inspired by the attractive and unique features andpotential benefits of advanced UNDERWATER communica-tions, the topic of UNDERWATER WIRELESS networks hasattracted increasing attention from researchers not onlyin academia, but also in the military and industrial sec-tors. While a great deal of research efforts have beenmade in recent years to UNDERWATER WIRELESS networks,the aforementioned challenges posed by underwateracoustic as well as optical WIRELESS channel exploitation infuture UNDERWATER WIRELESS system developments stillremain an open problem. As we are launching the firstFeature Topic of IEEE COMMUNICATIONS Magazinefocus-ing on UNDERWATER WIRELESS COMMUNICATIONS and network -ing, we aim at addressing the urgent needs in both theoryand application aspects by industry, military, and theresearch community in order to better understand therecent progress, explore the future potential researchdirections, and define new research paradigms in under-water WIRELESS COMMUNICATIONS and networks.

5 Theresponse to our Call for Papers on this Feature Topicwas overwhelming, with a total of 52 articles submittedfrom all around the world. Going through the rigoroustwo-round review process, Part 1 of this Feature Topiccontains eight excellent articles focusing on the key issuesand emerging concepts of contemporaneous underwaterwireless networks and first article, Realizing UNDERWATER Communica-tion through Magnetic Induction, introduces the magnet-ic induction as a new alternative communication paradigmtackling the high propagation-delay, low data-rates, andhighly environment-dependent UNDERWATER WIRELESS com-munications and networks.

6 The second article, UnderseaLaser communication with Narrow Beams, demonstratesthe two main advantages of narrow-beam optical commu-nication: increased power throughput and decreased tem-poral spread using Monte Carlo analysis under theundersea scattering environment. The third article, Secu-rity and Privacy in Localization for UNDERWATER SensorNetworks, addresses the security and privacy issues inunderwater localization by proposing their schemesIEEE COMMUNICATIONS Magazine November 201540 GUESTEDITORIALUNDERWATERWIRELESSCOMMUNIC ATIONS ANDNETWORKS:THEORY ANDAPPLICATION: PART1 TMandar ChitreCOMMAG_GUEST_EDITORIAL-Zhang_Guest Editorial 11/2/15 2:06 PM Page 40 IEEE COMMUNICATIONS Magazine November 201541 GUESTEDITORIAL against the attacks and investigating the techniques forprivacy preservation during the localization process.

7 Thefourth article, Software-defined UNDERWATER AcousticNetworks: Towards a High-rate Real-time ReconfigurableModem, investigates adopting the software-defined radioprinciples in UNDERWATER acoustic networks and proposesand analyzes the software-defined acoustic modem proto-type. The fifth article, Routing Protocols for UnderwaterWireless Sensor Networks, overviews the existing routingprotocols in under-water-sensor-networks through classify-ing them into two categories based on a route decisionmaker, and investigates and compares their various per-formance issues. The sixth article, Turbo Equalizationfor Single-Carrier UNDERWATER Acoustic Communica-tions, investigates the time- and frequency-domain Turboequalization schemes with low-complexity for MIMO Sin-gle-Carrier Modulation systems in UNDERWATER acousticcommunications infrastructure.

8 The seventh article, Structured Sparse Methods for Active Ocean Observa-tion Systems with communication Constraints, presentsan ocean monitoring infrastructure with multiplemobile/static acoustic sensors for field reconstruction, tar-get tracking, and exploration-exploitation. The eighth arti-cle, UNDERWATER Sensor Networks: A New Challenge forOpportunistic Routing Protocols, proposes the promisingopportunistic-routing protocols for UNDERWATER wirelesssensor networks by employing dynamic-relay schemes toovercome bandwidth, reliability, and propagation-delayconstraints. We would like to thank all the authors for their excel-lent contributions and all the reviewers for their valuablereviewing comments.

9 We also appreciate strong supportsfrom Dr. Sean Moore, the former Editor-in-Chief, and Gebizlioglu, the current Editor-in-Chief of IEEEC ommunications Magazine, and the IEEE Publicationsteam. Finally, we hope that the readers find this FeatureTopic interesting and stay tuned for new developments inthis research area and Part II of this feature topic inFebruary his degree from The University of Michigan. He is aFull Professor at Texas A&M University, has published over 300 researchpapers, received NSF CAREER Award in 2004, is IEEE Distinguished Lec-turer, and received four IEEE Best Paper Awards.

10 He is author of an IEEEBEST READINGS journal paper. He has been Editors for numerous IEEET ransactions/Journals, TPC Chair for IEEE GLOBECOM 2011, and TPC Vice-Chair for IEEE INFOCOM her degree from UCLA in 2003. She is now aFull Professor at the University of Connecticut. Her recent research mainlyfocuses on UNDERWATER sensor networks, autonomous UNDERWATER vehiclenetworks, cyber-aquatic systems, smart ocean technology and ocean com-puting. Jun-Hong co-founded ACM WUWNet (International Conference onUnderwater Networks and Systems), and is now serving as its steeringcommittee chair.