The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Underwater optical imaging has several drawbacks inherent to the physical medium such as light attenuation and turbidity. Sonars try to obviate those issues although, typically, they have lower resolutions. Combining visual and sonar data in underwater applications is still not popular, but researchers' interest in the topic is growing. However, with the advent of recent higher resolution sonar systems,...
We propose an architecture for an FPGA-based tester for a 3D stacked IC. Our design exploits the underlying structure of the FPGA, allowing it to be used to efficiently store and apply predefined test patterns at a high bandwidth, reducing the FPGA resources required and often reducing scan shift toggling. The proposed approach and its advantages can generally also be applied to 2.5D multi-die circuits...
A key to developing autonomous maritime systems for NATO is communication among data gathering platforms below and above the water. However, unlike the mature technologies that are used for terrestrial networks, underwater communications is still in an early stage. This paper provides an overview of CMRE's activities in the field of underwater communications where emphasis has been put in addressing...
Circuit boards are especially vulnerable to security attacks. Many routes and pins can be probed directly. Other pins may be controlled and observed through the JTAG boundary scan port. The JTAG port may also provide access to each chip's internal scan chains. Furthermore, modern chips may include embedded instruments that can be accessed through the chip's JTAG port and an internal IEEE P1687 scan...
This work proposes a novel approach to enhance Autonomous Underwater Vehicles (AUVs) navigation through the addition of localisation services to networked acoustic communication. The approach is based on the inclusion of timing information within acoustic messages through which it is possible to know the exact time of an acoustic transmission in relation to its reception. The exploitation of such...
There are currently no digital underwater communications standards. In this paper we describe JANUS, a simple multiple-access acoustic protocol designed and tested by the NATO Centre for Maritime Research and Experimentation (CMRE) over the past 6 years that provides a basic and robust tool for collaborative underwater communications. JANUS is in process to become a NATO standard but is not intended...
The Porto University testbed developed under the SUNRISE FP7 project is described along with its intended uses for experimentation with Future Internet technologies. First, the SUNRISE project and the FIRE initiative are briefly described as background information for the presentation of the testbed. Second, the key components of the testbed are presented with reference to ocean going autonomous vehicles,...
The interest in underwater communication has grown rapidly in the last few decades, as the ability to deploy assets at sea with increased levels of autonomy naturally led to the problem of getting data to and from them. Despite it's mature research topic status, underwater acoustic communications still faces high barriers when it comes to reaching consensus, not only on the communication processes...
This paper covers the first steps in creating a Software Defined Open Architecture Modem (SDOAM). Potentially useful operating environments, platforms and approaches are reviewed as well as relevant work on underwater digital communications at CMRE, including JANUS. A high-level architectural structure, based on a generalisation of the classic OSI communications stack, is proposed, identifying the...
Today's chips often contain a wealth of embedded instruments and data, including sensors, hardware monitors, built-in self test (BIST) engines, and chip IDs, among others. IEEE P1687 was specifically designed to provide access to such instruments in an efficient manner, and some companies are already implementing the proposed standard on their chips. However, while instruments provide valuable information...
IEEE P1687 is a valuable tool for accessing on-chip instruments during test, diagnosis, debug, and board configuration. However, most of these instruments should not be available to an end user in the field. We propose a method for hiding instruments in a P1687 network that utilizes a “locking” segment insertion bit (LSIB) that can only be opened when pre-defined values, corresponding to a key, are...
The possibilities opened with the increased use of autonomous underwater vehicles and their potential interactions with existing or prospective submerged sensor networks create an end-user technological pull on the communication capabilities for the underwater domain. Simulation models, while fundamental in the scientific and technological development process cannot offer the feature richness of the...
The integration of Radio Frequency (RF) Command and Control (C2) networks with underwater (UW) networks that are based on acoustic communications requires comprehensive solutions to address several technical challenges and interoperability issues. A major constraint arises from the large capability gap between acoustic and RF communications, the former being characterized by very low data rates and...
Many MAC protocols have been proposed for underwater sensor networks, usually variants of well-known terrestrial approaches. Although performance comparisons among different MAC protocols have been estimated by simulations, e.g. [1], [2], no extensive comparison has yet been performed by means of at-sea experiments. Simulations can only capture a subset of the total environmental variability, resulting...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.