Approximately 70% of the Earth’s surface is covered by water, yet almost 95% of the underwater world remains unexplored. Nearly 4000 robots are swimming up and down in the world’s oceans, which allow scientists to measure and understand ocean dynamics, like the directions and speeds of currents, as well as physical characteristics like temperature and salinity, yet scientists can only recover the collected sensor data and track the position of the robots only when they rise to the surface or when the robots are retrieved at the end of a mission. Real-time data retrieval of frequent measurements, continuous tracking of underwater robots and increased spatial coverage and sensing from a network of submerged robots/sensors is hindered by the limited communication speed and absence of GPS underwater. This hampers a wide range of activities, including real-time underwater sensing, sea-life monitoring, port surveillance, ocean mapping, subsea infrastructure inspection, wireless diver-to-diver communication, wireless diver/underwater vehicle communication, untethered sea exploration, subsea search-and-rescue operations, underwater wireless video feeds, and off- shore drilling monitoring.

Recent developments in adaptive underwater communications, robust direction finding for GPS-less underwater localization, software-defined underwater acoustic modems, and soft robotics for low-cost macro/micro autonomous underwater vehicles (AUVs) are notable enabling technologies to achieve faster communication speeds, accurate positioning, and low-cost testbed deployments underwater. Further research is required to understand the physical environment and spatiotemporal characteristics of the underwater acoustic channel, application constraints and programmability, size, weight, and power of next-generation underwater wireless platforms to enable the design, development, and deployment of underwater wireless networks of robots/sensors at scale.

The purpose of this Special Issue is to solicit original research papers on all aspects of underwater wireless communications and networking, including (but not restricted to):

*Localization
-communication-based navigation for low-cost AUVs
-localization, detection, classification, and tracking
-simultaneous localization and mapping
-short-data-record under-ranked localization
-graph localization
*Physical layer
-modulation/coding/signal processing/arrays
-channel modeling/prediction
-autonomous communications (receiver feedback/transmitter adaptivity)
-secure LPD/LPI communications
-full-duplex
*Networking
-channel sharing under high latency
-routing protocols
-crosslayer networking, handover, and meshing
-application-specific system level optimization
-distributed mobile networking
*Wireless Platforms and Applications
-software-defined acoustic/ultrasonic/optical modems
-sensor integration
-next generation platforms
-arctic, oil and gas/smart aqua/agriculture
-testbeds

Dr. Dimitris A. Pados
Dr. George Sklivanitis
Guest Editors


A special issue of Sensors(https://www.mdpi.com/journal/sensors) (ISSN 1424-8220). This special issue belongs to the section "Sensor Networks(https://www.mdpi.com/journal/sensors/sections/sensornetworks)".

Deadline for manuscript submissions: January 31, 2021.

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com(https://www.mdpi.com/) by registering(https://www.mdpi.com/user/register/) and logging in to this website(https://www.mdpi.com/user/login/). Once you are registered, click here to go to the submission form(https://susy.mdpi.com/user/manuscripts/upload/?journal=sensors). Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors(https://www.mdpi.com/journal/sensors/instructions) page. Sensors(https://www.mdpi.com/journal/sensors/) is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors(https://www.mdpi.com/journal/sensors/instructions) page before submitting a manuscript. The Article Processing Charge (APC)(https://www.mdpi.com/about/apc/) for publication in this open access(https://www.mdpi.com/about/openaccess/) journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service(https://www.mdpi.com/authors/english) prior to publication or during author revisions.

For more information, please contact Dr. Dimitris Pados (dpados@fau.edu) and Dr. George Sklivanitis (gsklivanitis@fau.edu).