No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
DBR: Depth-Based Routing for Underwater Sensor Networks
Abstract
Providing scalable and ecient routing services in underwater sensor net- works (UWSNs) is very challenging due to the unique characteristics of UWSNs. Firstly, UWSNs often employ acoustic channels for communications because radio signals do not work well in water. Compared with radio-frequency channels, acous- tic channels feature much lower bandwidths and several orders of magnitudes longer propagation delays. Secondly, UWSNs usually have very dynamic topology as sen- sors move passively with water currents. Some routing protocols have been proposed to address the challenging problem in UWSNs. However, most of them assume that the full-dimensional location information of all sensor nodes in a network is known in prior through a localization process, which is yet another challenging issue to be solved in UWSNs. In this paper, we propose a depth-based routing (DBR) protocol. DBR does not require full-dimensional location information of sensor nodes. Instead, it needs only local depth information, which can be easily obtained with an inex- pensive depth sensor that can be equipped in every underwater sensor node. A key advantage of our protocol is that it can handle network dynamics eciently with- out the assistance of a localization service. Moreover, our routing protocol can take advantage of a multiple-sink underwater sensor network architecture without intro- ducing extra cost. We conduct extensive simulations. The results show that DBR can achieve very high packet delivery ratios (at least 95%) for dense networks with only small communication cost.
... To perform this, the intermediate node decides in which direction the vector will point. While transmitting data from one SN to another, the approach known as "depth-based routing" (DBR) [18] considers the relative depths of the SNs. Since a SN in UWSN delivers data packets downward to the sink node, a SN in DBR will not send a data packet to another SN until that node is at a shallower depth, indicating that it is closer to the surface so that a SN in a UWSN network's DBR may relay data packets to the sink node. ...
... In order to ascertain the fresh position of the search agent and prevent clashes amidst SAs, Vector ⃗ is computed employing the subsequent Equation (18). ...
... This section assesses the performance of the proposed protocol by comparing it to that of three prominent UWSN protocols: DBR [18], EE-DBR [25,26], and EE-LHCR [37]. The performance is evaluated assuming a three-dimensional environment with dimensions of 1000 m × 1000 m × 1000 m and a total of 100 nodes distributed over 200-mhigh virtual layers. ...
Energy efficiency is important for underwater sensor networks. Designing such networks is challenging due to underwater environmental traits that hinder network lifespan extension. Unlike terrestrial protocols, underwater settings require novel protocols due to slower signal propagation. To enhance energy efficiency in underwater sensor networks, ongoing research concentrates on developing innovative solutions. Thus, in this paper, an intelligent bio-inspired autonomous surveillance system using underwater sensor networks is proposed as an efficient method for data communication. The tunicate swarm algorithm is used for the election of the cluster heads by considering different parameters such as energy, distance, and density. Each layer has several clusters, each of which is led by a cluster head that continuously rotates in response to the fitness values of the SNs using the tunicate swarm algorithm. The performance of the proposed protocol is compared with existing methods such as EE-LHCR, EE-DBR, and DBR, and results show the network’s lifespan is improved by the proposed work. Due to the effective fitness parameters during cluster head elections, our suggested protocol may more effectively achieve energy balance, resulting in a longer network lifespan.
... Depth-based routing (DBR) [26] use single-metric depth difference to decide candidate relays, which greedily forwards data packets to the nodes with lower depth towards the surface sinks. DBR has no consideration for the priority rotation and balancing energy consumed among the nodes but attempts to minimize energy consumption, which causes a shorter network lifetime. ...
... We divided the monitoring area into four layers, and the average height of a layer was 250 m. Meanwhile, the LLF-FR was compared with the classical DBR [26], ORD [10], DVOR [18] and Flooding broadcast under the same experimental conditions. For fairness, the main parameters of LLF-FR (including omnidirectional and directional transmission powers, receiving power, data rate, etc.) were set referring to [10,18,26], as shown in Table 3. E low is the minimum energy required to forward a packet to the node. ...
... Meanwhile, the LLF-FR was compared with the classical DBR [26], ORD [10], DVOR [18] and Flooding broadcast under the same experimental conditions. For fairness, the main parameters of LLF-FR (including omnidirectional and directional transmission powers, receiving power, data rate, etc.) were set referring to [10,18,26], as shown in Table 3. E low is the minimum energy required to forward a packet to the node. We set λ as 1% of initial energy. ...
Energy-efficient and reliable underwater acoustic communication attracts a lot of research due to special marine communication conditions with limited resources in underwater acoustic sensor networks (UASNs). In their final analysis, the existing studies focus on controlling redundant communication and route void that greatly influence UASNs’ comprehensive performances. Most of them consider directional or omnidirectional transmission for partial optimization aspects, which still have many extra data loads and performance losses. This paper analyzes the main issue sources causing redundant communication in UASNs, and proposes a lightweight differentiated transmission to suppress extra communication to the greatest extent as well as balance energy consumption. First, the layered model employs layer ID to limit the scale of the data packet header, which does not need depth or location information. Second, the layered model, fuzzy-based model, random modeling and directional-omnidirectional differentiated transmission mode comb out the forwarders step by step to decrease needless duplicated forwarding. Third, forwarders are decided by local computation in nodes, which avoids exchanging controlling information among nodes. Simulation results show that our method can efficiently reduce the network load and improve the performance in terms of energy consumption balance, network lifetime, data conflict and network congestion, and data packet delivery ratio.
... The reliability of data transmission is improved by adopting a routing confirmation mechanism. Depth-based UWRPs [6]- [10] are location-free protocols that utilize depth information of nodes during the next-forwarding node selection. The depth of the node from the water surface is the key attribute considered for the selection of the next-forwarding node. ...
... The selection of the actual forwarding node from the candidate set depends on other factors like residual energy, depth threshold, and signal-to-noise ratio (SNR) of the sensor node. DBR is the most popular routing protocol proposed by Yan et al. [6] and it uses multi-sink architecture. Wahid et al. [7] proposed energy-depth based routing (EEDBR) where both depth and residual energy information are considered for choosing the next forwarding node, to improve network lifetime. ...
... Let mobile sinks reach the left end of the region at time t=TL. On reaching the left end horizontal trajectory of the Layer-i sink's instantaneous position is defined by (6) to (8), ...
Scientific, commercial, exploration, and monitoring applications of underwater sensor networks have drawn the attention of researchers toward the investigation of routing protocols that are robust, scalable, and energy efficient. This has brought significant research in network layer routing protocols. Irrespective of the field of application it is desirable to increase network lifetime by reducing energy consumed by sensor nodes in the network or by balancing energy in the entire network. Energy balancing refers to the uniform distribution of the network’s residual energy such that all nodes remain alive for a long time. It requires uniform energy consumption by each sensor node in the network instead of the same node being involved in every transmission. In this paper, we discuss two routing methods for three-dimensional environments in which the water region under monitor is divided into subregions of equal height and each subregion has a sink. Nodes in the subregion send data to the sink designated for that subregion. The first method called static multi-sink routing uses static sinks and the second method called horizontal trajectory-based mobile multi-sink routing (HT-MMR) uses mobile sinks with a horizontal trajectory. Simulation results show that the proposed HT-MMR reduces average energy consumption and average energy tax by 16.69% and 16.44% respectively. HT-MMR is energy efficient as it enhances network lifetime by 11.11%.
... Yan, H. et al. [19] proposed a depth-based routing protocol with a greedy algorithm, DBR (depth-based routing), which differs from other protocols in that it does not need to use specific geographic location information. Instead, it uses depth as a factor for selecting the next hop node and only requires depth information. ...
... The node temporarily stores the packet in a cache queue for the next send. 11: end 12: if y has received data packets then 13: node y sends ACK 14: end 15: if x has received ACK then 16: Packets are transmitted successfully 17: else 18: x retransmits data packets (up to three times) 19: ...
Due to challenges posed by long propagation distances, high mobility, limited bandwidth, multipath propagation, and Doppler effects in underwater acoustic sensor networks (UASNs), the design of routing protocols faces numerous complexities. To enhance reliability in sparse node regions and reduce network energy consumption, this paper proposes a dependable and energy-efficient routing protocol termed WLQRP for weighting link-quality-based routing protocol. WLQRP leverages link quality information between nodes for data forwarding. When computing the link quality between nodes, it considers not only the historical transmission success ratio between nodes and their immediate relay but also incorporates the link quality between the relay and the relay’s next-hop nodes. This approach effectively reduces the likelihood of encountering void regions. Moreover, the protocol judiciously selects the next-hop node to improve transmission success rates, thereby minimizing data packet retransmissions and reducing energy consumption. We conduct MATLAB simulations to evaluate the WLQRP protocol, comparing it against the VBF (vector-based forwarding) and the HH-VBF (hop-by-hop vector-based forwarding) underwater routing protocol. Experimental results demonstrate that WLQRP enhances network performance in terms of data transmission rate, energy consumption, and end-to-end delay. These findings validate the efficacy of the proposed protocol.
... The scheme runs on depth information of other nearby nodes based on routing path creation. In DBR [18], Selecting the appropriate sensor is a critical aspect of routing protocols in wireless sensor networks as it determines the efficiency of data communication. One common method of sensor selection involves selecting the sensor with the lowest depth for packet forwarding. ...
... The sink node was located on the surface of the water and transmitted data packets to the satellite, which then sent the information to the control center. To assess the performance of the proposed protocols, one protocol was selected from each classification discussed in section 4. We have considered the DBR [18], EEDBR [13], SEEC [4], CTP-SEEC [1]underwater routing protocols. ...
Study Framework : The system of geographical information (GIS) is a computerized method for collecting, storing, disseminating, querying, updating, processing and analyzing geographic data. (GIS) enables the collection of diverse spatial data from various sources and transforms it into an information board for multiple users to boost productivity. Intelligent techniques, remote sensing, and underwater Wireless sensor networks are applied to improve GIS dramatically. Remote sensing data sources for GIS come from underwater sensor networks, The implementation of effective sensing devices, intelligent mobile nodes, and a multi-hop routing system can facilitate the efficient and optimal routing of traffic towards the basin or base station. They have been using GIS , which has revolutionized response scenarios with its ability to collect, analyze and manipulate spatial points.
The objective of the study : The aim of this research is to differentiate the significant routing protocol issues that are relevant to underwater sensor networks. These networks serve as key transceivers that have established mechanisms for seamless and efficient data transmission.
The mechanisms : The article presented a performance evaluation simulation based on a comparison of five different routing protocols that perform to promote GIS execution. A rigorous comparison of the outcomes varied by five routing protocols, where it evaluated with random mobility UnderWater sensor model based on the varied network parameters, was performed to validate this work.
The continued to improve results : The suggested study in this manuscript contains spatial-information services universal to routing protocols to aid a group of navigators in harsh circumstances. According to the findings of the study, the CTP-ABS-SEEC routing protocol demonstrated superior performance compared to the other four routing protocols (CTP-SEEC, SEEC, EEDBR, and DBR) in the specified network configuration.
... Yan et al. [14] described a depth-based routing protocol to handle depth rate whereas the depth node contains a pressure sensor node to forward data in a greedy manner to handle the network dynamic topology without any assistance from the localization service. Te data packet in DBR contains all the depth information and forwards the packets from one hop to another hop. ...
Underwater wireless sensor nodes comprise hundreds to thousands of battery-operated sensor nodes with limited bandwidth. These networks are employed to transmit the data with enhanced quality of service (QoS). However, efficient data routing is the most challenging obstacle in many underwater applications. To solve the issues in underwater sensor nodes, the hybridized cluster-based geographical opportunistic routing protocol with distance vector establishment has been proposed to transmit the data efficiently. Primarily, the proposed methodology finds out the shortest path with minimal hop count whereas the void node can be updated with infinite hop count. Thereafter, the sleep/wake scheduling and waiting mechanism and periodic beaconing algorithm are incorporated into the proposed model to attain a higher packet delivery ratio with minimal energy consumption. This proper scheduling and optimal cluster routing enhance the continuous data transmission in underwater applications. The simulation result reveals that the proposed method achieves better energy efficiency and higher network lifetime when compared with the existing clustering methods.
... In this section we compare the simulations results of both DRAR and Co-DRAR protocols with existing DBR [31] protocol. The techniques presented in [32] and in [20] also use DBR as a reference. ...
The reliability of Underwater Wireless Sensor Networks (UWSNs) is measured in terms of energy consumption (EC), end-to-end delay(E2E), and packet delivery ratio (PDR). The adverse effects of a channel may cause data loss. Reducing delay up to the possible extent improves the reliability of the network, also increasing the number of nodes in a particular network increase reliability. Besides, increasing the number of nodes improves reliability but also increases power consumption. In order to overcome these shortcomings, the two routing protocols are proposed in this paper, namely Delay and Reliability Aware Routing (DRAR) protocol and Cooperative Delay and Reliability Aware Routing (Co-DRAR) protocol for UWSNs. In the DRAR protocol, the network is divided into two equal regions where two sink nodes(SNs) are positioned at the upper region of the network and two SNs are placed at the mid-region of the network. The protocol chooses the relay node based on residual energy (RE), distance, and Bit Error Rate (BER). These parameters protect the data packets from corruption and also provide a stable path (where nodes remain active for longer periods and do not die quickly). The protocol uses a single link and may get worse sometimes while changing channel circumstances. To address this problem, a cooperative routing scheme is added to the DRAR protocol in order to develop its enhanced version known as the Co-DRAR protocol. The protocol works by allowing the destination to receive multiple copies of data packets in order to decide the quality of packets. The proposed protocols DRAR and Co-DRAR perform routing irrespective of the geographical position of sensor nodes conversely to some conventional routing protocols. This is why our proposed protocols perform than the well-known protocol i.e. Depth base routing (DBR) in terms of EC, E2E, PDR, dead nodes, packet drop ratio, and number of alive nodes (ANs).
... For USN, many network architectures have been put forth in the literature. The depth detected by each node was used as a routing metric in the depth-based routing protocol, which was proposed in [36]. A different dynamic routing algorithm that is based on the number of hops between the transmitter and reception nodes was put forth in [37]. ...
Due to growing concerns regarding their use in fields including oceanography, commercial marine operations, and military surveillance, demand in the exploration of underwater sensor networks for marine studies has developed. Network channels for underwater sensor network (USN) rapidly change (spatially and temporally) depending on the surroundings. To increase system efficiency by adjusting transmission parameters to channel fluctuations, it is alluring to utilize adaptive modulation and coding (AMC) for USNs. In order to determine the best link adaptation method based on the channel quality, this article focuses on evaluating a measured sea trial dataset utilizing a rule-based approach (i.e., three-dimensional evaluation, modulation-wise analysis, and a fixed-SNR strategy). To determine the optimum AMC combinations in terms of channel adaptively, we draw a situation of the measured USN data rate versus Bit Error Rate (BER) and Signal to Noise Ratio (SNR). The work further extends to apply machine learning (ML) methods to identify the MCS levels by looking into the channel characteristics due to the non-reversibility limitation of the rule-based strategy. One of the ML methods we used for the investigation, gradient boosted regression tree (GBRT), exhibits impressive accuracy of 99.988% in classifying MCS levels. The MCS levels are related to channel statistics and signal characteristics, particularly those that are susceptible to SNR and BER limitations, using an ensemble of trees that learns from the buoy and base station’s uplink data.
... To do this, we compare EQAFR with both SDN-based and non-SDN-based solutions. The non-SDN-based method is a well-known underwater routing protocol named Depth Based Routing (DBR) (Yan et al. 2008) which is used in most underwater-specific literature. In DBR, each node broadcasts a packet if the packet comes from a lower depth. ...
During the last few years, the Internet of Underwater Things (IoUT) has become an interesting technology to discover unexplored underwater environments. IoUT enables scientists and researchers to remotely discover underwater phenomena and gather valuable information from the depths of the oceans using smart things. Due to the harshness of the underwater environment, collecting information with regard to QoS parameters and energy considerations is a major challenge. Software Defined Networking (SDN) is a centralized network management paradigm that helps to implement efficient routing approaches to provide QoS for network traffic flows. In this paper, we propose EQAFR as an energy-efficient routing schema by leveraging the capabilities of SDN to provide QoS for gathered underwater data which are sent from underwater things toward the sink. EQAFR is implemented in the SDN controller to gather the coordinate information and residual energy of things periodically. Then, it computes the delay and probability of data loss of the link and applies Fuzzy logic to compute the cost of links. Finally, it calculates optimal paths and installs the routes between the underwater things. Simulation results confirm that using EQAFR considerably improves QoS and prolongs the lifetime of underwater things.
... However, depth-based routing algorithms merely take into account the local depth of sensor nodes each and do not require complete location information. Some well-known depth-based routing systems are depth-based routing (DBR) [14], energy-efficient depth-based routing (EEDBR) [15], and weighting depth and forwarding area division depth-based routing (WDFAD-DBR). DBR calculates the holding time of a packet using the depth information provided by sensor nodes. ...
Wireless transmission of information using water as a communication channel is one of the potential technologies for the progress of potential underwater observation systems including applications from aquaculture to the oil industry, submarine detection, instrument monitoring, and forecast of natural turbulence and study of marine life. Underwater wireless sensor networks applications are exhilarating but demanding at the same time. Some of the challenges faced by underwater networks are the movement of nodes in three-dimensional space because of which the network could not be well thought-out as a fixed topology, limited bandwidth, exceedingly low data rates, limited battery power, failures due to pollution, and corrosion, and a lot more. Additionally, as acoustic communications consume more power than terrestrial radio ones do, more sophisticated signal processing methods are needed at the receiver to make up for the channel's deficiencies. One of these difficulties is creating a routing protocol for the complexity of an underwater environment. The major aim of all these protocols is to advance data packets toward the sink to lessen the propagation delay, lessen energy expenditure, and utilize the least amount of bandwidth by restricting the broadcasting of multiple copies of the data packet. This article surveys various routing schemes and various challenges involved in the design and development of these routing schemes.
... Many research work focused on reducing energy consumption through network and data-link layer management, proposing new techniques to manage these layers [3]. Modern general-purpose modems such as those provided by EvoLogics tend to transmit at powers between 8.5W-60W in a range of data rates in the hundreds of kB/sec ranges depending on range and data-rate characteristics [4]. ...
As the Internet of Things (IoT) continues to find new applications, there is academic and industrial interest in expanding these concepts to the oceanic environment where data is traditionally challenging to communicate wirelessly, establishing an Underwater Internet of Things. One of the main challenges is rendering the network energy efficient to avoid regular retrievals for battery recharging processes, which can be expensive. The work proposes using low powered networks with multiple hops to reduce cost by avoiding the need for large transmitters, transformers and high rated components, thus rendering the technology cheaper and more accessible. The investigation found that even at low transmission powers a robust underwater acoustic network can be developed over hundreds of meters distance between hops, capable of carrying small packets of sensor data commonly used in Internet of Things applications. The successful delivery ratio and the signal-to-noise ratio metrics are used to assess the robustness of the network as a function of power. The analysis demonstrated that lower power levels exhibit higher energy efficiency when compared to their counterparts employing higher powers, aligning with the trends observed in commercial products, consuming significantly less energy than current single hop networks potentially allowing for longer life Underwater Wireless Sensor Networks.
... In this section, we will evaluate the performance of the proposed routing protocol APCDBRP and compare it with several existing protocols, including DBR [6], EEDBR [7], and EAVARP [14]. We will implement our protocol and the comparative protocols using AquaSim-Next Generation [26], which is a simulator for underwater sensor networks based on NS3 [27] and its libraries. ...
Low energy consumption has always been one of the core issues in the routing design of underwater sensor networks. Due to the high cost and difficulty of deployment and replacement of current underwater nodes, many underwater applications require the routing protocol design to consider the network lifetime extension problem. Based on this, we designed a new routing protocol that takes into account both low energy consumption and balanced energy consumption, and achieves effective extension of the network lifetime, called adaptive power-controlled depth-based routing protocol for underwater wireless sensor networks (APCDBRP). The protocol consists of two phases: (1) the route establishment phase and (2) the data transmission phase. In the route establishment phase, the initial path is established by the sink node broadcasting beacon packets at the maximum transmission power. The receiving nodes update their routing tables based on the beacon information and forward the beacon packets. In the data transmission phase, APCDBRP introduces a novel forwarding factor that considers both energy efficiency and energy balance. It selects the optimal next hop based on high energy efficiency and relatively abundant energy, thus extending the network’s lifetime. Additionally, APCDBRP proposes a new data protection and route reconstruction mechanism to address issues such as network topology changes due to node mobility and data transmission failures. Our simulation is based on AquaSim–Next Generation, which is a specialized tool built on the NS3 platform for researching underwater networks. Simulation results demonstrate that, compared to other typical routing protocols, APCDBRP exhibits superior performance in reducing network energy consumption and extending the network’s lifetime. It also achieves a high packet delivery rate with lower energy consumption.
... Sink placement at the best position tends to perform enhancement. Many algorithms such as [14][15][16][17] designed network in a single solid structure and placed the sink on the top. Placement of the sink on such positions leads to high and imbalance data load. ...
... In [12], a classical depth-based routing (DBR) protocol, also known as a locality-free protocol, is proposed. This algorithm uses a greedy flooding strategy, in which sensor nodes calculate the depth using depth sensors, and high-depth sensor nodes transmit data packets to low-depth sensor nodes until they reach the sink. ...
Underwater sensor nodes are usually deployed by ships, aircraft, etc., in random drops, and there is current movement in the underwater environment, which results in an uneven distribution of sensor nodes and thus, different energy consumption in each area of the network. In addition, the underwater sensor network also has a “hot zone” problem. To address the uneven energy consumption of the network caused by the above problem, the non-uniform clustering algorithm for energy equalization is put forward. Considering the residual energy, density and coverage redundancy of nodes, this algorithm selects the cluster heads and makes them more reasonably distributed. Additionally, according to the selected cluster heads, the size of each cluster is designed to equalize the energy consumption of the network during multi-hop routing. In this process, the residual energy of cluster heads and the mobility of nodes are considered, and real-time maintenance is performed for each cluster. The simulation results demonstrate that the proposed algorithm is effective in prolonging the network lifetime and balancing the network energy consumption; moreover, the network coverage maintenance is better than that of other algorithms.
... In Depth-Based Routing protocol (DBR) [42], the depth of the node uses to forward the packets to the sink nodes. It does not require expensive localization service [43,44]. ...
Underwater Sensor Networks have been proposed to monitor underwater regions. One of the major problems with underwater communication is the limited power supply of the underwater nodes, leading to costly transmission collisions. In this work, we propose an any-cast transmission scheduling algorithm for Underwater networks. Moreover, we propose a location-based algorithm that schedules transmissions between sensor nodes and sink nodes, where each sensor node is matched with exactly one sink and it sends its data to this sink only to minimize the possibility of collision. This reduces the number of costly re-transmissions and leads to efficient energy consumption. The proposed algorithm is evaluated using NS2 Aqua-Sim simulator, where the experiment results show that the proposed algorithm can provide up to 25% in energy savings, decrease the transmission collisions up to 31%, decrease the average delay up to 16%, and increase the delivery ratio up to 40% compared with a simple greedy algorithm.
... Sink placement at the best position tends to perform enhancement. Many algorithms such as [14][15][16][17] designed network in a single solid structure and placed the sink on the top. Placement of the sink on such positions leads to high and imbalance data load. ...
Designing an efficient, reliable, and stable algorithm
for underwater acoustic wireless sensor networks(UA-WSNs).
... Figure 1 present an illustration of the proposed architecture. There exist various routing techniques for acoustic communications, such as Depth Based Routing (DBR) [9], Vector Based Forwarding [10], and Hop to Hop Vector Based Forwarding (HH-VBF) [11,12]. Nevertheless, vulnerabilities persist within the wireless VLC network concerning the routing of information across the VLC aquatic channels. ...
The prevalence of oceanic industry and ocean borne interests has given rise to the concept of the Underwater Internet of Things as a vector for automation and data analytics in an environment hostile to anthropomorphic activity. Through the Internet of Underwater Things, it is theorised that sensors along the ocean floor or otherwise can be densely connected to the internet through wireless acoustic or optical links. However, both technologies have significant disadvantages that prevent either becoming a dominant technology. This project proposes a wireless software defined multimodal network infrastructure, that is proven using channel modelling and power analysis calculations, to be capable of robustly transmitting sensor data from source to sink by managing each technology according to its optimal environment. It was found that it is achievable to populate an opto-acoustic network in such a way that Successful Delivery Ratio becomes 90%-100% in clear water whilst achieving a 17% saving in overall energy consumption in a network mounted on a pipeline at 200 m depth when compared to a stand-alone equivalent acoustic network.
... If defined threshold is greater than this factor, node schedules the data, and it will be forwarded on priority basis. DBR [9] is the first routing scheme that uses depth to forward the data to destination. DBR forwards the data packets using a greedy approach. ...
Underwater acoustic communication is a suitable method that facilitates underwater applications. However, the dynamic underwater acoustic environment poses many challenges, such as the three-dimensional expensive energy constraint deployment of nodes, the limited bandwidth, and the movement of nodes due to water currents. This leads to a void hole in the under aquatic region and affects the network performance in terms of packet ratio and energy consumption. To address these issues, we propose two routing protocols named Pro-GEDAR and GEEDAR for under acoustic communication that route data packets from sensor nodes to sonobuoys via opportunistic geographic routing. When a communication void hole occurs, both methods switch to recovery mode instead of using control messages to analyze and discover routing paths along the communication void hole region. The recovery mode procedure relies on the topology control information through improved depth adjustment of the void nodes with a proactive approach. The method significantly improves network performance in sparse and dense distributed networks with maximum traffic load. Our experimental results prove that the performance of our routing protocols is better in terms of fraction of void node, depth adjustment and packet delivery ratio compared to other schemes.
... Most traditional UASN geolocation routing is designed using an OR paradigm [19]. Yan et al. proposed the classical depth-based routing (DBR) [20] protocol, where the source node forwards the packet to the next hop with lower depth using the greedy criterion. The DBR protocol is based on multiple sinks, which increases PDR and reduces end-to-end latency. ...
In Underwater Wireless Sensor Networks (UWSNs), data should be transmitted to data centers reliably and efficiently. However, due to the harsh channel conditions, reliable data transmission is a challenge for large-scale UWSNs. Thus, opportunistic routing (OR) protocols with high reliability, strong robustness, low end-to-end delay, and high energy efficiency are widely applied. However, OR in UWSNs is vulnerable to routing attacks. For example, sinkhole attack nodes can attract traffic from surrounding nodes by forging information such as the distance to the sink node. In order to reduce the negative impact of malicious nodes on data transmission, we propose an intrusion detection scheme (IDS) based on the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) clustering algorithm for OR (DOIDS) in this paper. DOIDS is based on small-sample IDS and is suitable for UWSNs with sparse node deployment. In DOIDS, the local monitoring mechanism is adopted. Every node in the network running DOIDS can select the trusted next hop. Firstly, according to the behavior characteristics of common routing attack nodes and unreliable underwater acoustic channel characteristics, DOIDS selected the energy consumption, forwarding, and link quality information of candidate nodes as the detection feature values. Then, the collected feature information is used to detect potential abnormal nodes through the DBSCAN clustering algorithm. Finally, a decision function is defined according to the time decay function to reduce the false detection rate of DOIDS. It makes a final judgment on whether the potential abnormal node is malicious. The simulation results show that the algorithm can effectively improve the detection accuracy rate (3% to 15% for different scenarios) and reduce the false positive rate, respectively.
... In the multi-hop data collection scheme, nodes transmit data to the sink node through a multi-hop process of underwater acoustic communication. A typical multi-hop collection method is depth-based routing protocol (DBR) [15]. DBR transmits data to sink node along the direction of depth reduction. ...
The Underwater Internet of Things (UIoT) hasemerged as one of the prominent technologies in the developmentof future ocean monitoring systems, where mobile edge elements(such as autonomous underwater vehicles, AUVs) provide apromising method for the data collection from sensor nodes.However, as an important part of the UIoT, underwater wirelesssensor networks (UWSNs) are severely affected by the underwater dynamic environment. For instance, node locations changecontinuously, which significantly increases the difficulty of datacollection. To solve this problem, the concept of an inevitablecommunication space (ICS) is proposed. The ICS is calculatedby analyzing the variation in the position of nodes and thecommunication range. Furthermore, an ICS-based dynamic datacollection algorithm (ICS-DDCA) for UIoT is proposed to collectunderwater data. This method utilizes the ICS instead of theinitial location of the node for data collection to further improvethe performance of the algorithm and shorten the data collectiontime. The simulation results demonstrate that the ICS-DDCAcan effectively reduce the collection time, while ensuring the fullcompletion of data collection. Compared to EEDA and PNCS-GHA, ICS-DDCA reduces the time required for data collectionby 24.15% and 24.22% on the average respectively.
... The data in SNR among un coded and coded frameworks is called coding gain and the estimation of coding gain relies upon 3 factors: The sort of ECC, code rate and unraveling calculation (i.e., the intricacy of translating calculation). The lower signal force transmission prerequisite at the transmitter (because of coding gain) which comes at the expense of additional vitality utilization because of channel encoding, channel interpreting and the transmission of excess pieces presented by FEC [18][19][20]. In this way, we have to think about the additional force utilization acquainted due with encoding, deciphering and transmission of additional pieces and the force sparing because of utilization of FEC. ...
In underwater acoustic communication, the information transmitted from 1 sensor node to another is corrupted due to errors persuaded by the noisy channel and other issues. To reduce the bit error rate, it is essential to propose suitable error regulator structure. In this paper, we simulate the performance analysis of Orthogonal Frequency Division Multiplexing Interleaver Division Multiple Access Multiple Input Multiple Output scheme with different channel codes to improve bit error rate performance. Bit error rate and consumed power are measured by communicating arbitrarily generated information through AWGN network. From the simulation results and assessment of the 2 divergent channel coding, 2 interleavers and 3 modulation techniques. We conclude that turbo codes with random interleaver and binary phase shift keying are best suitable to improve reliability performance for underwater wireless acoustic communication. To reduce the burst error in underwater acostic communication we propose an hybrid approach IDMA OFDM MIMO. BER performance is improved upto 10−6. HIGHLIGHTS In underwater acoustic communication to reduce bit error rate, we simulate the performance analysis of Orthogonal Frequency Division Multiplexing Interleaver Division Multiple Access Multiple Input Multiple Output scheme We propose a hybrid approach with 2 divergent channel coding, 2 interleavers and 3 modulation techniques Finally, we observe from simulation results that turbo code with binary phase shift keying and random interleaving improves bit error rate performance GRAPHICAL ABSTRACT
Long-term underwater acoustic sensor networks (UASNs) are widely deployed for marine scientific and industrial applications. The widespread ocean currents lead to variations in the communication range of location-fixed nodes equipped with non-omnidirectional transducers, which will reduce the successful packet relaying probability. In order to reduce the impact of ocean current on packet relaying, we propose an adaptive routing protocol for underwater acoustic sensor networks with ocean current (OCAR). By adaptively selecting candidate nodes based on communication range, OCAR improves the successful packet relaying probability in poor communication conditions caused by ocean current. Firstly, the impact of ocean current on communication range is demonstrated by constructing a communication range model and a sea trial. Secondly, successful packet relaying probability is improved by selecting the communicable nodes under ocean current as the candidate nodes. Next, the transmitter-based adaptive routing scheme reduces the number of nodes responding to the relay packet and adaptively reselects the destination node per hop. Therefore, energy consumption is reduced and the packet delivery ratio (PDR) is improved. Finally, routing recovery and candidate set dynamic update are achieved to improve successful packet relaying probability. Simulation results show that, compared with Flood, OCAR can achieve a maximum 98.29% reduction in energy consumption and 37.05% reduction in average end-to-end delay while maintaining close to 100% PDR. In addition, compared with VBF, OCAR can achieve close to 100% PDR when the PDR of VBF is 0, maximum energy consumption reduction of 84.41% and average end-to-end delay reduction of 96.34%.
A submerged sensor network comprises of numeral different sensors and independent submerged vehicles sent to facilitate submerged, associate, and divide data between themselves to complete detecting and observing capacities. The submerged sensor networks have a wide scope of utilizations like contamination observing, catastrophic anticipations, facilitated route, under ocean investigations, an advanced military capacity, mine investigation, and so on. Submerged sensor networks present extraordinary tests to the current advances utilized in earthly sensor organization since submerged climate varies from earthbound radio climate regarding energy expenses and channel engendering peculiarities. Audile remote correspondence is utilized instead of wireless recurrence and optical sign in submerged sensor organization. A portion of the issues where submerged sensor network contrast from earthly are restricted for data transfer capacity, battery power, and disappointment of sensor hubs due to snarling and consumption.
The ocean contains abundant resources and has high scientific and economic values. Increasing underwater communication scenarios stimulates many research efforts on underwater wireless ad-hoc networks. Underwater acoustic communication technology supports medium to long-range wireless communication. However, it suffers from low transmission data rates and long link delays. This paper introduces an Acoustic-Radio Cooperation Network (ARCNet) model for more efficient maritime information transmission. Under this ARCNet, we propose a new Radio-Acoustic Opportunistic Hybrid (RAOH) routing protocol composed of a neighbor discovery mechanism and a hybrid routing strategy. In the neighbor discovery stage, we explore the surface radio links to aid in selecting the shortest delay path between an underwater node and the surface nodes. In the route establishment stage, we combine the advantages of opportunistic routing and on-demand routing and design an opportunistic hybrid routing strategy, which improves the success rate of data forwarding and reduces the time spent on route establishment. Simulation results show that the proposed RAOH protocol outperforms traditional terrestrial and underwater routing strategies in routing response speed, packer delivery rate, throughput, end-to-end delay, and energy efficiency.
Underwater wireless sensor network (UWSN) is one of the kinds of wireless sensor network (WSN). This type of network is suitable for underwater areas such as pools, rivers, seas, and oceans. In UWSN, the energy of nodes is more depletes compared to WSN. As more energy in nodes depletes for transmitting data, therefore routing is the most important issue for UWSN. Sensor nodes in water use acoustic waves to transmit data packets contrary to sensor nodes in WSN which are used radio waves for this purpose, hence the link quality of the acoustic and radio waves is different. Therefore, it is impossible to use routing methods and protocols based on WSN for UWSN. This article focuses on routing in UWSN and proposes a depth source selection phase via link quality between sensor nodes with mobile sink(s) for improving energy-saving and network lifetime. The new proposed algorithm contains six phases are as follows: network architecture, calculating link quality, clustering, source selection, mobile sink mechanism, and transmitting data packets phase. Also, the new approach is suitable for small and large networks. Results of experimental simulation clearly show that this new proposed algorithm improves residual energy and network lifetime by at least 40.28% and 58.88% respectively.
By receiving information and relaying these facts to the earth stations, underwater sensor networks (UWSNs) play a vital role in ocean research and monitoring. As a result, creating effective routing protocols is essential because they ensure secure and trustworthy data transport from the source nodes to the destination nodes. Designing a routing protocol is a challenging task due to the effects of the underwater environment. This article highlights the common routing protocol design challenges and lists the benefits and drawbacks of the most widely used routing protocols for UWSNs. In more detail, the three major categories of routing protocols are localization-based, localization-free, and cooperative systems. Dealing with different performance parameters including energy use, reliability, network longevity, delay, and communication expenditures, the performance of such protocols is discussed.KeywordsUnderwater sensor networks (UWSNs)Routing protocolsAcoustic wavesCooperating routing (CP)
Recently, sensor networks have emerged as a very powerful technique for many applications, including monitoring, measurement, surveillance and control. The idea of applying sensor networks into underwater environments (i.e., forming underwater sensor networks) has received increasing interests. Even though underwater sensor networks (UWSNs) share some common properties with ground sensor networks, such as the large number of nodes and limited energy, UWSNs are significantly different from the conventional ground sensor technology. First, radio communications do not work well under the water. They must be replaced by acoustic communications, which have very different travel time and characteristics. In particular, acoustic channels feature large propagation latency, low bandwidth capacity and high error rate. Second, while most ground sensors are static, underwater sensor nodes may move with water currents and other underwater activities. Due to the very different environment properties and also the unique nature of the aquatic applications, the protocols developed for ground sensor networks are not directly applicable to underwater sensor networks. Simple underwater monitoring systems have been introduced in the past. However, they are small-scale and rely on point-to-point, single channel techniques such as remote telemetry or sequential local sensing. In UWSN, the sensor nodes have a limited transmission range, and their processing and storage capabilities as well as their energy resources are also limited. Routing protocols for wireless sensor networks are responsible for maintaining the routes in the network and have to ensure reliable multi-hop communication under these conditions. In this paper, we give a survey of routing protocols for UWSN and compare their strengths and limitations.
An efficient routing protocol is critical for the data transmission of underwater wireless sensor networks (UWSNs). Aiming to the problem of void region in UWSNs, this article proposes a reinforcement learning-based opportunistic routing protocol (DROR). By considering the limited energy and underwater environment, DROR is a receiver-based routing protocol, and combines reinforcement learning (RL) with opportunistic routing (OR) to ensure real-time performance of data transmission as well as energy efficiency. To achieve reliable transmission when encountering void regions, a void recovery mechanism is designed to enable packets to bypass void nodes and continue forwarding. Furthermore, a relative
${Q}$
-based dynamic scheduling strategy is proposed to ensure that packets can efficiently forward along the global optimal routing path. Simulation results show that the proposed protocol performs well in terms of end-to-end delay, reliability, and energy efficiency in UWSNs.
The reliability of Underwater Wireless Sensor Networks (UWSNs) is measured in terms of energy consumption (EC), end-to-end delay(E2E) and packet delivery ratio (PDR). The adverse effects of channel may cause data loss. Reducing delay up to possible extend improves the reliability of the network, also increasing the number of nodes in a particular network increase reliability. Besides, increasing the number of nodes improve reliability but also increase power consumption. In order to overcome these shortcomings, the two routing protocols are proposed in this paper, namely Delay and Reliability Aware Routing (DRAR) protocol and Cooperative Delay and Reliability Aware Routing (Co-DRAR) protocol for UWSNs. In DRAR protocol, network is divided into two equal regions where two sink nodes(SNs) are positioned at upper region of the network and two SNs are placed at the mid region of the network. The protocol choose the relay node based on residual energy (RE), distance and Bit Error Rate (BER). These parameters protect the data packets from corruption and also provide stable path (where nodes remain active for longer period and do not die quickly). The protocol uses single link and may get worse sometimes while changing channel circumstances. To address this problem, cooperative routing scheme is added to DRAR protocol in order to developed its enhanced version known as Co-DRAR protocol. The protocol works by allowing the destination to receive multiple copies of data packets in order to decide the quality of packets. The proposed protocols DRAR and Co-DRAR perform routing irrespective to geographical position of sensors nodes conversely to the some of conventional routing protocols that's way our propose protocol better perform than the well-known protocol i.e. Depth base routing (DBR) in terms of EC, E2E, PDR, dead nodes, packet drop ratio and number of alive nodes (ANs).
The Internet of Underwater Things (IoUT) has attracted a lot of attention because of its promising applications in underwater environmental monitoring; however, the characteristics of acoustic communication, e.g., long propagation delay and high attenuation, pose great challenges for efficient and reliable underwater data transmission. Currently, opportunistic routing is regarded as a key technology to improve the packet delivery ratio, because it can dynamically choose several forwarding nodes and leverage their cooperative forwarding to increase network throughput. However, choosing an excessive number of forwarding nodes may result in energy waste and lengthy communication delays. Therefore, an Opportunistic Routing based on Directional Transmission (ORDT) is studied to improve packet delivery timeliness and reliability and lower energy consumption. ORDT mainly contains three phases: forwarding area division, candidate forwarder selection, and candidate forwarder coordination. The forwarding region is first established based on directional transmission. Only neighbors located in the forwarding region can forward packets. Following that, candidate forwarders in the forwarding region are chosen depending on their forwarding capability. Additionally, the chosen candidate’s time of holding packets is specified so that they might collaborate to reduce redundant data transmission and transmit packets to gateway nodes. Then, an Autonomous Underwater Vehicle (AUV) is employed to gather packets from gateway nodes. Simulation findings demonstrate that ORDT performs better than existing opportunistic routing in terms of packet delivery success rate, transmission latency, and energy usage.
With the rise of the upsurge of exploiting marine resources and the rapid development of the research of terrestrial wireless sensor networks, the research of underwater wireless sensor networks (UWSNs,) has become a new research hotspot. In UWSNs, routing protocol plays a very important role as one of the important components. This paper introduces several classical routing algorithms from the following categories: location, sector, reinforcement learning, and intelligent optimization algorithms. Finally, the paper also summarizes and prospects the research direction of underwater wireless sensor network routing algorithms.
The long propagation delay of acoustic links leads to the complex randomness of packet collision, which reduces the network packet delivery rate (PDR) and aggravates network congestion. A single vector hydrophone with directional reception characteristics can concentrate the reception gain on a certain direction, which can increase spatial reuse, reduce packet collision, and help to improve the performance of the underwater acoustic wireless sensor networks (UASNs). Herein, this paper proposes a cross-layer protocol with low interference and low congestion (CLIC) based on directional reception. An integrated routing-medium access control (MAC) design is also devised in the CLIC scheme to use the directional beams to create the least-interfering, highest-capacity data transmission links, weighing key factors affecting network performance to obtain routes with low collisions and low congestion. Simulation results show that the CLIC has a higher packet delivery rate (PDR) and higher energy efficiency compared to the QELAR, CITP, and VBF protocols.
Underwater Acoustic Sensor Networks (UASNs) play a vital role in many applications such as underwater resource exploration, environment monitoring, and surveillance. These applications demand high reliability. However, achieving reliable communication in the UASNs is one of the challenging issues due to varying link quality. To improve the reliable transmission in the UASNs, Opportunistic Routing (OR) is a promising routing technique. One of the challenges OR protocols face is cooperation between nodes. To overcome this, many techniques have been found. Holding time is one of the mainly used techniques to coordinate between nodes. Various holding time algorithms already exist. The difference in the algorithms is the use of different parameters for calculating hold time, and depth difference is the most used parameter. The major goal of this paper is to create a framework in UnetStack3 for holding time-based protocols that can be used for numerous different protocols to compute hold time and overhear neighboring packets by doing minor modifications in the calculations.
Sink mobility brings new challenges to large-scale sensor networking. It suggests that information about each mo- bile sink's location be continuously propagated through the sensor eld to keep all sensor nodes updated with the di- rection of forwarding future data reports. Unfortunately frequent location updates from multiple sinks can lead to both excessive drain of sensors' limited battery power sup- ply and increased collisions in wireless transmissions. In this paper we describe TTDD, a Two-Tier Data Dissemination approach that provides scalable and ecient data delivery to multiple mobile sinks. Each data source in TTDD proac- tively builds a grid structure which enables mobile sinks to continuously receive data on the move by ooding queries within a local cell only. TTDD's design exploits the fact that sensor nodes are stationary and location-aware to con- struct and maintain the grid structures with low overhead. We have evaluated TTDD performance through both analy- sis and extensive simulation experiments. Our results show that TTDD handles multiple mobile sinks eciently with performance comparable with that of stationary sinks.
There exists an increasing demand for reliable, high capacity Underwater Acoustic Networks (UANs), as evidenced by the large volume of research invested over the last decade in overcoming the difficulties inherent with propagation of information bearing signals through shallow water regions. Application interests include oceanographic information gathering, environmental monitoring, and coastal defense (anti-submarine and mine/counter-mine warfare). Two specific examples of the recent efforts to develop and field UANs in shallow water regions are the Deployable Autonomous Distributed System funded by the Office of Naval Research (ONR) and the Autonomous Oceanographic Sampling Network sponsored by ONR and the National Science Foundation. The Deployable Autonomous Distributed System (DADS), envisioned to provide undersea surveillance in littoral waters [Rice 2()()()1, is an underwater array of fixed sensor plattorms, interconnected by acoustic modems. The network connects the remote sensor plattorms to a coim%and center through a portal that relays data received from the acoustic network to the distant coim%and facility across satellite links. Acoustic data is propagated through the network over multi-hop coim%unications paths. The individual hops are configured as half duplex code division multiple access links between discrete modem pairs. Messages are relayed between paired platton%s to minimize the transmit power requirements and reduce the impact of tempon%l, spatial, and frequency spreading of the signal as it propagates through the littoral channel.
Ocean bottom sensor nodes can be used for oceano-graphic data collection, pollution monitoring, offshore explo-ration and tactical surveillance applications. Moreover, Un-manned or Autonomous Underwater Vehicles (UUVs, AUVs), equipped with sensors, will find application in exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic network-ing is the enabling technology for these applications. Underwater Networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area. In this paper, several fundamental key aspects of underwater acoustic communications are investigated. Different architectures for two-dimensional and three-dimensional underwater sensor networks are discussed, and the underwater channel is char-acterized. The main challenges for the development of efficient networking solutions posed by the underwater environment are detailed at all layers of the protocol stack. Furthermore, open research issues are discussed and possible solution approaches are outlined.
Large-scale Underwater Wireless Sensor Network (UWSN) is a novel networking paradigm to explore the uninhabited and complex oceans. However, the characteristics of UWSNs, such as huge propagation delay, floating node mobility, and limited acoustic link capacity, are significantly different from ground-based wireless sensor networks and existing small scale Underwater Acoustic Networks (UANs). The novel networking paradigm poses inter-disciplinary challenges that will require new technological solutions. In particular, in this technical report we adopt a top-down approach to explore the research challenges in UWSN design. Along the layered protocol stack, we roughly go down from the top application layer to the bottom physical layer. At each layer, a set of new design intricacies are studied. The conclusion is that building scalable and distributed UWSNs is a challenge that must be answered by inter-disciplinary efforts of acoustic communications, signal processing and mobile acoustic network protocol design.
In this paper, we tackle one fundamental problem in Underwater Sensor Networks (UWSNs): robust, scalable and energy efficient
routing. UWSNs are significantly different from terrestrial sensor networks in the following aspects: low bandwidth, high
latency, node float mobility (resulting in high network dynamics), high error probability, and 3-dimensional space. These
new features bring many challenges to the network protocol design of UWSNs. In this paper, we propose a novel routing protocol,
called vector-based forwarding (VBF), to provide robust, scalable and energy efficient routing. VBF is essentially a position-based
routing approach: nodes close to the “vector” from the source to the destination will forward the message. In this way, only
a small fraction of the nodes are involved in routing. VBF also adopts a localized and distributed self-adaptation algorithm
which allows nodes to weigh the benefit of forwarding packets and thus reduce energy consumption by discarding the low benefit
packets. Through simulation experiments, we show the promising performance of VBF.
This paper investigates a fundamental networking problem in underwater sensor networks: robust and energy-efficient routing. We present an adaptive location-based routing protocol, called hop-by-hop vector-based forwarding (HH-VBF). It uses the notion of a "routing vector" (a vector from the source to the sink) acting as the axis of the "routing pipe", similar to the vector based forward (VBF) routing in the work of P. Xie, J.-H. Cui and L. Lao (VBF: Vector-Based Forwarding Protocol for Underwater Sensor Networks. Technical report, UCONN CSE Technical Report: UbiNet-TR05-03 (BECAT/CSE-TR-05-6), Feb. 2005). Unlike the original VBF approach, however, HH-VBF suggests the use of a routing vector for each individual forwarder in the network, instead of a single network-wide source-to-sink routing vector. By the creation of the hop-by-hop vectors, HH-VBF can overcome two major problems in VBF: (1) too small data delivery ratio for sparse networks; (2) too sensitive to "routing pipe" radius threshold. We conduct simulations to evaluate HH-VBF, and the results show that HH-VBF yields much better performance than VBF in sparse networks. In addition, HH-VBF is less sensitive to the routing pipe radius threshold. Furthermore, we also analyze the behavior of HH-VBF and show that assuming proper redundancy and feedback techniques, HH-VBF can facilitate the avoidance of any "void" areas in the network.
This paper explores applications and challenges for underwater sensor networks. We highlight potential applications to off-shore oilfields for seismic monitoring, equipment monitoring, and underwater robotics. We identify research directions in short-range acoustic communications, MAC, time synchronization, and localization protocols for high-latency acoustic networks, long-duration network sleeping, and application-level data scheduling. We describe our preliminary design on short-range acoustic communication hardware, and summarize results of high-latency time synchronization
Wireless sensor networks are expected to be deployed in harsh environments character- ized by extremely poor and fluctuating chan- nel conditions. With the generally adopted single-sink architecture, be it static or mo- bile, such conditions arise due to contention near the sink as a result of multipath data delivery. The compactness of sensors with limited energy resources restricts the use of sophisticated FEC or ARQ mechanisms to improve the reliability of transmissions under such adverse conditions. We propose a novel virtual sink architec- ture for wireless sensor networks that mit- igates the near-sink contention by defining a group of spatially diverse physical sinks. Reliability and energy efficiency is achieved through multipath data delivery to the sinks without the need for sophisticated FEC or ARQ mechanisms. This architecture is espe- cially suitable for indoor environments, where channel conditions are harsh due to severe multipath fading, as well as emerging applica- tions like underwater sensor networks where the predominant physical layer is acoustic communications, which is characterized by long propagation delays and severely fluctuat- ing link conditions. We present our proposed architecture and demonstrate its efficacy using mathematical analysis.
Underwater sensor networks are attracting increasing in-terest from researchers in terrestrial radio-based sensor net-works. There are important physical, technological, and eco-nomic di erences between terrestrial and underwater sensor networks. Previous surveys have provided thorough back-ground material in underwater communications, and an in-troduction to underwater networks. This has included detail on the physical characteristics of the channel [1], on under-water acoustic communications [2, 3, 4], and surveys of un-derwater acoustic networks [5, 6, 7, 8]. In this survey, we highlight a number of important practical issues that are not emphasized in the recent surveys of underwater networks, with an intended audience of researchers who are moving from radio-based terrestrial networks into underwater net-works. We focus on issues relevant to medium access control (MAC) protocols, which are an area of continuing work both
Advances in micro-sensor and radio technology will enable small but smart sensors to be deployed for a wide range of environmental monitoring applications. In order to constrain communication overhead, dense sensor networks call for new and highly efficient methods for distributing queries to nodes that have observed interesting events in the network. A highly efficient data-centric routing mechanism will offer significant power cost reductions [17], and improve network longevity. Moreover, because of the large amount of system and data redundancy possible, data becomes disassociated from specific node and resides in regions of the network [10][7][8]. This paper describes and evaluates through simulation a scheme we call Rumor Routing, which allows for queries to be delivered to events in the network. Rumor Routing is tunable, and allows for tradeoffs between setup overhead and delivery reliability. It's intended for contexts in which geographic routing criteria are not applicable because a coordinate system is not available or the phenomenon of interest is not geographically correlated.
Recent technology advances in low-cost, low-power chip designs have made feasible the deployment of large-scale sensor networks.
Although data forwarding has been among the first set of issues explored in sensor networking, how to reliably deliver sensing
data through a vast field of small, vulnerable sensors remains a research challenge. In this paper we present GRAdient Broadcast
(GRAB), a new set of mechanisms and protocols which is designed specifically for robust data delivery in spite of unreliable
nodes and fallible wireless links. Similar to previous work [1], GRAB builds and maintains a cost field, providing each sensor in the network the direction to forward sensing data. Different
from all the existing approaches, however, GRAB forwards data along an interleaved mesh from each source to the receiver.
The width of the forwarding mesh is controlled by the amount of credit carried in each data message, allowing the degree of
delivery robustness to be adjusted by the sender. GRAB design harnesses the advantage of large scale and relies on the collective
efforts of multiple nodes to deliver data, without dependency on any individual ones. As demonstrated in our extensive simulation
experiments, GRAB can successfully deliver above 90% of data with relatively low energy cost even under adverse conditions
of up to 30% node failures compounded with 15% link packet losses.
Routing in large-scale mobile ad hoc networks is challenging because all the nodes are potentially moving. Geographic routing can partially alleviate this problem, as nodes can make local routing decisions based solely on the destinations' geographic coordinates. However, geographic routing still requires an efficient {\em location service}, i.e., a distributed database recording the location of every destination node. Devising efficient, scalable, and robust location services has received considerable attention in recent years. The main purpose of this paper is to show that {\em node mobility} can be exploited to disseminate destination location information {\em without incurring any communication overhead}. We achieve this by letting each node maintain a local database of the time and location of its last encounter with every other node in the network. This database is consulted by packets to obtain estimates of their destination's current location. As a packet travels towards its destination, it is able to successively refine an estimate of the destination's precise location, because node mobility has ``diffused'' estimates of that location. We define and analyze a very simple algorithm called EASE (Exponential Age SEarch) and show that in a model where $N$ nodes perform independent random walks on a square lattice, the length of the routes computed by EASE are on the same order as the distance between the source and destination {\em even for very large $N$.} Therefore, without exchanging any explicit location information, the length of EASE routes are within a constant factor of routes obtained with perfect information. We discuss refinements of the EASE algorithm and evaluate it through extensive simulations. We discuss general conditions such that the mobility diffusion effect leads to efficient routes without an explicit location service. In practical settings, where these conditions may not always be met, we believe that the mobility diffusion effect can complement existing location services and enhance their robustness and scalability.
The salient features of acoustic communications render many schemes that have been designed for terrestrial sensor networks unusable underwater. We therefore propose a novel virtual sink architecture for underwater sensor networks that aims to achieve robustness and energy efficiency under harsh underwater channel conditions. To overcome the long propagation delay and adverse link conditions in such environments, we make use of multipath data delivery. While conventional multipath routing tends to lead to contention near the sink, we avoid this caveat with the virtual sink design involving a group of spatially diverse physical sinks. Hence, we are able to exploit the reliability achieved from redundancy provided by multipath data delivery while mitigating the contention between the nodes.
Underwater acoustic networks are generally formed by acoustically
connected ocean bottom sensor nodes, autonomous underwater vehicles
(AUVs), and surface stations that serve as gateways and provide radio
communication links to on-shore stations. The quality of service of such
networks is limited by the low bandwidth of acoustic transmission
channels, high latency resulting from the slow propagation of sound, and
elevated noise levels in some environments. The long-term goal in the
design of underwater acoustic networks is to provide for a
self-configuring network of distributed nodes with network links that
automatically adapt to the environment through selection of the optimum
system parameters. This article considers several aspects in the design
of shallow water acoustic networks that maximize throughput and
reliability while minimizing power consumption
Advances in processor, memory and radio technology will enable small and cheap nodes capable of sensing, communication and computation. Networks of such nodes can coordinate to perform distributed sensing of environmental phenomena. In this paper, we explore the directed diffusion paradigm for such coordination. Directed diffusion is datacentric in that all communication is for named data. All nodes in a directed diffusion-based network are application-aware. This enables diffusion to achieve energy savings by selecting empirically good paths and by caching and processing data in-network. We explore and evaluate the use of directed diffusion for a simple remote-surveillance sensor network.
Introduction h this paper we introduce a new routing protocol for ad hoc networks built around two novel observations. One, called the distance eflect, usw the fmt that the greater the distance separating two nodes, the slower they appear to be moving with respect to each other. Accor@gly, the location information in routing tables can be updated as a function of the distance separating nodes without compromising the routing accuracy. The second idea is that of triggering the sending of location updates by the moving nodes autonomously, based ody on a node's mobility rate. htuitively, it is clear that in a direction routing dgorithrn, routing information about the slower moving nodes needs to be updated less frequently than that about hig~y mobtie nodw. h this way e~ node can optimize the frequency at which it sends updates to the networks and correspondingly r~ duce the bandwidth and energy used, leading to a fully distributed and self-optimizing system. B~ed on thwe routing tablw, the proposed direction algorithm sends messages in the "recorded dwectionn of the destination node, guaranteeing detivery by following the direction with a given probability. We show by detailed simda- tion that our protocol always delivers more than 80% of the data messages by following the direction computed, without using any recovery procedure. In addition, it mintilzes the overhead used for maintaining routes us- ing the two new principlw of update message frequency and distance. Lastly, the dgorithrn is fully distributed, provides loop-free paths, and is robust, since it suppfies multiple routes.
Advances in processor, memory and radio technology will enable small and cheap nodes capable of sensing, communication and computation. Networks of such nodes can coordinate to perform distributed sensing of environmental phenomena. In this paper, we explore the directed diusion paradigm for such coordination. Directed diusion is datacentric in that all communication is for named data. All nodes in a directed diusion-based network are applicationaware. This enables diusion to achieve energy savings by selecting empirically good paths and by caching and processing data in-network. We explore and evaluate the use of directed diusion for a simple remote-surveillance sensor network. 1 Introduction In the near future, advances in processor, memory and radio technology will enable small and cheap nodes capable of wireless communication and signicant computation. The addition of sensing capability to such devices will make distributed microsensing|an activity in which a collection of ...
In this paper, we present a family of adaptive protocols, called SPIN (Sensor Protocols for Information via Negotiation) , that eciently disseminates information among sensors in an energy-constrained wireless sensor network. Nodes running a SPIN communication protocol name their data using high-level data descriptors, called meta-data. They use meta-data negotiations to eliminate the transmission of redundant data throughout the network. In addition, SPIN nodes can base their communication decisions both upon application-specic knowledge of the data and upon knowledge of the resources that are available to them. This allows the sensors to eciently distribute data given a limited energy supply. We simulate and analyze the performance of two specic SPIN protocols, comparing them to other possible approaches and a theoretically optimal protocol. We nd that the SPIN protocols can deliver 60% more data for a given amount of energy than conventional approaches. We also nd that, in terms...
We present Greedy Perimeter Stateless Routing (GPSR), a novel routing protocol for wireless datagram networks that uses the positions of routers and a packet's destination to make packet forwarding decisions. GPSR makes greedy forwarding decisions using only information about a router's immediate neighbors in the network topology. When a packet reaches a region where greedy forwarding is impossible, the algorithm recovers by routing around the perimeter of the region. By keeping state only about the local topology, GPSR scales better in per-router state than shortest-path and ad-hoc routing protocols as the number of network destinations increases. Under mobility's frequent topology changes, GPSR can use local topology information to find correct new routes quickly. We describe the GPSR protocol, and use extensive simulation of mobile wireless networks to compare its performance with that of Dynamic Source Routing. Our simulations demonstrate GPSR's scalability on densely deployed wir...