The term Underwater Sensor Network is also known as UWSNs which is typically the distributed arrangement of underwater sensors fixed at the bottom of the ocean. These nodes are further connected to underwater gateways through any wireless media. The main intention of Underwater Sensor Network Localization is to establish communication among nodes of underwater and surface station.
Here, underwater sensors sense the environmental data and transfer it either within the network or surface station through multi-hop links. When the sensor senses the data, it is necessary to include both time and location information for current UWSN applications especially for location-aware data like disaster prevention, pollution monitoring, etc. Particularly, location-awareness is more crucial for following scenarios,
- Fast routing for search query
- Moving target tracking
- Spontaneous data dissemination
In the coming sections, we are going to see the various aspects of localization in underwater communications. All this information is valuable for active scholars since we considered different attributes of localization in UWSN.
And, we have emphasized several localization/positioning basics, schemes, techniques, algorithms, technologies, etc. For the add-on benefits, our research team has also included the recent research challenges and issues regarding Underwater Sensor Network Localization. Further, we provide the best assistance in identifying current research problems and appropriate solutions than the existing techniques. Here, we have given what you exactly learn from this page. Explicitly, this page aims to answer the following questions:
- What are the localization enhancing solutions in underwater network?
- What are the advanced localization techniques / algorithms?
- What are the up-to-date localization research issues in underwater communication?
Basics of Underwater Sensor Network Localization
Generally, the UWSNs localization is the most important section in UOWNs. Also, you can recognize the localization concept in numerous real-time applications. For instance: underwater sensing, natural hazards prevention, defense surveillance, etc. All these applications provide location-aware services. However localization has a significant place in many applications, it also poses technical issues due to the high attenuation (optical / RF) and high propagation delay (acoustic) of underwater communication channels.
Although it has problems, we are here to provide solutions to tackle any of the issues. Our resource team has the objective of achieving flawless localization in underwater communication. So, we work on every aspect of localization. If there are complicated issues, we never give up instead we develop our techniques/algorithms to crack the problems. Below, we have given some common techniques specially used for the underwater localization process.
The objective of this page is to provide all-inclusive updates of underwater sensor network localization schemes with their algorithms!!!
Common Methods of Underwater Sensor Localization
Positioning Techniques / Algorithms
- Analysis of Scene
- Fingerprinting (Biometric-based)
- Detection of Proximity
- RFID and Cell-ID
- Triangulation (Angulation and Lateration)
- AOA, RTOF, TDOA, AOD, RSS-based and TOA
For illustration purposes, here we have elaborated the performance of location-based on the TOA algorithm. In this, we provide how the location of the unknown nodes is obtained with the help of known locations. Also, we have highlighted the techniques used in the localization process. Similarly, we are proficient to find solutions for your localization issues
- Anchors based Localization
- Consist of stationary anchor nodes with known location and mobile nodes with unknown locations
- Both anchor nodes and mobile nodes can transmit beacons either in synchronized or un-synchronized format
- Beacons can be of anything like ultrasound, radio frequency, etc.
- Through beacons, one can compute the following things
- Beacons Visibility / Invisibility
- Time of Arrival (ToA)
- Signature / Signal Strength
- Time Difference of Arrival (TDoA – time period between 2 beacons)
- In overall, we can achieve Angle of Arrival (AoA), area estimation and beacon distance
In addition, we have also given you other techniques of localization along with their communication technologies. Our developers have more than enough experience in handling the following techniques and algorithms. Further, we also recommend other add-on techniques in your project depend on the project objectives and requirements.
Underwater Sensor Network Technology
- Near Field Communication (NFC)
- Scheme – Proximity
- Algorithms – RSSI
- Audible Sound
- Scheme – Trilateration
- Algorithms – TOA
- Radio Frequency Identification (RFID)
- Scheme – Fingerprinting
- Algorithms – RSSI
- Infrared
- Scheme – Trilateration
- Algorithms – TDOA and TOA
- Ultra-wide Band (UWB)
- Scheme – Trilateration
- Algorithms – TDOA and TOA
- Optical / Vision
- Scheme – Proximity Detection and Scene Analysis
- Algorithms – RSSI
- Wide Local Area Network (WLAN)
- Scheme – Fingerprinting and Trilateration
- Algorithms – RSSI and TDOA
- Magnetic
- Scheme – Trilateration
- Algorithms – AOA and TOA
- Wireless Sensor Network (WSN)
- Scheme – Fingerprinting
- Algorithms – RSSI
- Bluetooth
- Scheme – Fingerprinting and Trilateration
- Algorithms – RSSI and TDOA
Next, we can see the current research issues of underwater sensor Network localization. These issues are itemized based on the key operations and entities of the underwater sensor network. So, all these issues are treated as fundamental problems that one should concern more while selecting the research topic. Our research team has designed several research solutions to overcome these problems effortlessly. Beyond these issues, we also framed solutions for other major and minor issues of underwater sensor localization.
Major Challenges and Issues of Underwater Sensor Network Localization
The major challenges for underwater localization are,
- Hostile underwater channel
- For any kind of carrier waves, the unpredictable variation of communication channel is severe
- Since, the impact of environmental disturbances will minimize the accuracy in range measurement
- The factors that affect measurements are reflection, attenuation, noise, absorption, reflection and scattering
- As a result, it may leads to high error in localization estimation
- Node Deployment
- Majorly, localization is prefer in large-scale distributed network which are constructed with both anchors and sensor nodes
- Synchronization
- Lack of time synchronization due to the unavailability of GPS signals in underwater
- Consequently, it may also leads to great localization error on using TOA-based ranging scheme
- Node Mobility
- Underwater sensors unavoidably often change their positions due to undesired environmental factors like current, micro-organisms, wind, turbulence, etc.
- In the case of anchors, the location can be easily identified by GPS but it is difficult to detect the location of mobile nodes
Taxonomy of Underwater Localization
In the exiting research, different localization techniques are introduced for the reason of tracking objects, tagging information, surveillance, and environmental monitoring. Commonly, it is categorized depends on various parameters/attributes. And they are:
- Anchor Free or Anchor-based
- Range Free Or Range-based
- Mobile or Stationary
- Optical or Acoustic
- Distributed or Centralized
In the above, we have already seen the primary techniques of localization. To the continuation, here we have given the list of localization schemes based on the taxonomy of underwater localization. All these schemes have special functionalities to accurately detect the location of unknown nodes in any hostile environment. In truth, these schemes are best in yielding precise results in our experience.
Localization Schemes for Underwater Communication
- Range-Free
- Centroid
- Hop count-based
- Signal Processing
- Area Localization
- Mobility-based
- Mobile / Dynamic
- Stationary / Static
- Hybrid
- Ranging-based
- Distributed Localization
- Infrastructure-oriented
- Without Reference Nodes / Anchors
- Mobile Anchors and Beacons-based
- Computation-based (distributed and central)
- Estimation-based
- Prediction-based
- Channel-based
- Optical
- Acoustic
- Hybrid
Important Factors for UWSNs Localization
In fact, all the above-specified localization schemes/algorithms work out on various network parameters. For instance: node capacity, network topology, energy requests/conditions, range measurement, etc. Furthermore, the accuracy estimation of localization techniques are based on the following network elements,
- Scheduling
- Propagation Losses
- Time Synchronization
- Number and Position of Anchor Nodes
Due to the continuous environmental variations, the attainment of accuracy is still a challenging task in localization. Since the factors that affect localization performance are unpredictable
Simulation Analysis of Underwater Sensor Networks Localization
So far, we have discussed the localization techniques and algorithms, now we can see the simulation requirements of the localization like OS, tools, and technologies. Simulation of localization algorithms at different scenarios will enable the developers to predict the performance of used algorithms by defining the least sensor requirements. Further, our developers are also given the basic requirements of implementing UWSN localization projects. Whereas, it includes operating systems, tools, and simulators as follow,
Requirements for UWSNs Simulation
Supported OS:
- TinyOS
- LiteOS
- uC / OS (Micro-Controller Operating Systems)
- Contiki
- eCos (Embedded Configurable Operating System)
Simulation Tools:
The underwater sensor network localization projects are can be implemented in different programming languages such as C++, C#, C, small kayak, etc. Similarly, these languages are supported in several networking Projects (tools and simulators) . For instance: the NS2 simulator supports other tools and modules such as NS miracle, Aqua Sim, Aqua Tools, Aqua Net, and Aqua Lab.
- NS2 (C++ and C)
- WOSS (C++)
- USNet (C++ and C)
- Aqua 3D (C++)
- SAMON (C++ and C)
- UANT (C++)
- Aqua Tune (Small kayak)
- UwSim (C#)
Our developers will also suggest the best-fitting development technologies for your project for appropriate research outcomes. Next, we can see the performance metrics of underwater sensor network localization since it only predicts the performance of localization techniques. It exactly defines how your proposed solutions efficiently achieve the expected results. For your information, here we have listed basic metrics of localization in UWSNs. Beyond these, we suggest more based on your project working principles.
Performance metrics for UWSNs simulation
- Localization Error
- Approximate distance between expected positions and actual positions of all nodes.
- Then, normalize the absolute localization error with respect to communication range of the node
- Average Communication
- Divide overall interchanged messages by total number of localized nodes where it considers both localization and beacon messages
- Localization Coverage
- Proportion of localizable nodes to total number of nodes
- Other Important Energy Efficiency Metrics
- Latency
- Time to Partition
- Energy Trade-offs
- Time to Coverage Loss
- Network Lifespan
- Energy per Reported Event
- Time to First Node Expiry
- Energy per Correctly Received Bit
- Time to First Event Announcement Failure
Overall, we promise you to provide complete research and code execution service in sophisticated technologies. Further, we also give manuscript writing and publication services with proofreading support for Underwater Sensor Network Localization Projects. So, if you are interested in avail of our best-expertized guidance and services, make a bond with us.