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An adaptive routing protocol in underwater sparse acoustic sensor networks
Abstract
Underwater acoustic sensor network (UASN) is a promising technique, which will facilitate a wide range of aquatic applications. However, because of adverse underwater environments, UASN faces grand challenges and problems such as limited bandwidth, node movement, long propagation delay, three-dimension deployment, energy-constraint, expensive manufacture and deployment costs. In order to address these problems and challenges, in this paper we propose an adaptive hop-by-hop vector-based forwarding routing protocol on the basis of HH-VBF (called AHH-VBF). Firstly, during the transmission process, the radius of virtual pipeline is adaptively changed hop by hop to restrict the forwarding range of packets so that the transmission reliability can be guaranteed effectively in the sparse sensor region and the duplicated packets can be reduced in the dense sensor region; secondly, the transmission power level is also adaptively adjusted hop by hop in cross-layer fashion so that the energy-efficiency can be improved effectively; thirdly, forwarding nodes are selected based on the distance from current node to destination node so that the end-to-end delays are reduced effectively. Eventually, we propose two metrics: propagation deviation factor and effective neighbor number, to evaluate the network performance of AHH-VBF. We conduct extensive simulations using ns-3 simulator and perform theoretical analyses to evaluate the network performance. Our experimental results verified that the AHH-VBF routing protocol outperforms HH-VBF protocol, naïve Flooding and RDBF in terms of energy efficiency, end-to-end delay and data delivery ratio.
... The majority of void-handling strategies for UWSNs utilize the bypassing the void region approach (e.g., [4], [6], [9], [13]- [25]), where the objective is to establish alternative paths for packets to be routed around the void region. In the power control approach (e.g., [26]- [30]), nodes in the void region increase their transmission powers to extend their communication ranges for finding a next-hop neighbor to forward the packets. In the mobility-assisted approach (e.g., [3], [5], [7], [11], [31]- [34]), the idea is to consume some energy to move the nodes inside the void regions to new depth locations for resuming the packet forwarding. ...
... In [2], bypassing the void regions as well as power control techniques are jointly utilized. In [35], void regions are avoided by the [13] Bypassing the Void Region Single-sink DFR [14] Bypassing the Void Region Single-sink EAVARP [15] Bypassing the Void Region Multi-sink EERVRM [16] Bypassing the Void Region Multi-sink EVA-DBR [17] Bypassing the Void Region Multi-sink Hydrocast [18] Bypassing the Void Region Multi-sink IVAR [6] Bypassing the Void Region Single-sink LVAR [19] Bypassing the Void Region Single-sink OVAR [4], [9] Bypassing the Void Region Single-sink REBAR [20] Bypassing the Void Region Single-sink RLOR [21] Bypassing the Void Region Single-sink RPSOR [22] Bypassing the Void Region Multi-sink VAPR [23] Bypassing the Void Region Multi-sink VBF [24] Bypassing the Void Region Single-sink VBVA [25] Bypassing the Void Region Single-sink AHH-VBF [26] Power Control Single-sink CARP [27] Power Control Single-sink FBR [28] Power Control Multi-sink LF-IEHM [29] Power Control Single-sink NA-TORA [30] Power Control Multi-sink CTC & DTC [11], [31] Mobility-Assisted Multi-sink DCR [5] Mobility-Assisted Multi-sink GEDAR [3], [7] Mobility-Assisted Multi-sink NGF [32] Mobility-Assisted Multi-sink RVPR [33] Mobility-Assisted Multi-sink WDFAD-DBR [34] Mobility-Assisted Multi-sink ...
... The sink nodes are deployed in a pre-determined manner as in [39] such that the surface of the water (which has a size of d 2 net m 2 ) is partitioned into |N S | number of equal-sized squares, where each sink node is placed on the center of these small squares. Each sensor node is assumed to know both its location and the location of the sink nodes [26]. ...
Underwater wireless sensor networks (UWSNs) typically suffer from the communication void region problem. A common method to handle the void region problem is to re-route the packets around the void regions. As the size of the void regions increases, packets require more hops to circumvent the large void regions, resulting in a short network lifetime. On the other hand, the void region problem is more destructive in UWSNs utilizing a single-sink architecture than a multi-sink architecture since nodes consume excessive energy for bypassing the void regions to reach the sink node, which can be positioned in a hard-to-reach area in single-sink UWSNs. In this work, an integer linear programming (ILP) model is developed for maximizing UWSNs lifetime while bypassing the void regions. Solving the ILP model to optimality, the joint impact of the void region size and the sink architecture type on UWSNs lifetime is investigated. The results show that the performance of UWSNs significantly drops as the size of the void region grows such that UWSNs lifetimes shorten by up to 61% as the total void region size is one-quarter of the network size. Moreover, multi-sink UWSNs yield better performance than single-sink UWSNs in the void region problem.
... Although the holding time of packet reduces the sufficient redundant transmission, but it shows a less performance in sparse regions comparatively to VBF, due to the small pipeline radius, which remain constant throughout the network. To overcome the issues of HH-VBF, AHH-VBF [15] protocol is proposed, which changes the direction of pipeline and radius of pipeline according to the provided information of location of neighbor nodes. The holding time is calculated on the basis of distance from current node to destination node, and the higher priority node forwards the data, which causes to reduce the propagation delay of the network. ...
... In recovery mode procedure, void node changes its position, stops beaconing and sends the void-node-message to its neighbors to schedule the procedure and calculate the new depth, which is described in line (1-7). If none of the predecessor nodes can carry on the recovery mode procedure, as the nodes have not been received any reply of void-node-message, then all generated packets are discarded, and after waiting time t voidnode runs the new procedure for evaluate the new depth(t) (lines [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Upon receiving void-node-message each node performs the recovery mode procedure to calculate its new depth in three hemisphere left, right and up. ...
... If node 'a' is a one or two hop neighbor, then void node N v must determine a new depth by moving a distance r 2 in its left direction, such that its distance to its closest sonobuoy is greater than the distance from node 'a' to its closest sonobuoy . Then new depth z d is added to the candidate set D c (lines [12][13][14][15][16][17][18][19]. In (line 21) void node N v find out the distance to node 'a' considering only X, Y coordinates, because in worst case N v could be at the same depth of node 'a'. ...
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.
... In [9], a greedy data transmission approach is used when source node is near to the destination node. Another technique, called AHH-VBF [19], that uses the radius information rather than angle for IoUT. Because acoustic wavelengths are used, using radius information quickly reduces energy consumption issues. ...
... For the selection of nodes and their route towards the destination, the hop-by-hop dynamic addressing based routing protocol for pipeline monitoring is discussed (H2-DARPPM) [15] [19]. The parametric value for the selection of nodes is energy consumption. ...
... On the contrary, the watchman nodes simply stop broadcasting from the sink, considering the network with the watchman and fixed later node IDs are completed (line [12][13][14][15][16][17][18]. If another node is left to assign watchman IDs, it simply continues broadcasting until the network nodes are equipped with watchman's (line [19][20][21][22][23]. (see algorithm 2). ...
Underwater Internet of Things (UIoT) is a network of smart interconnected objects operating in various aqueous environments. To avoid the signal absorption which occurs due to properties of water, the signals need to be transmitted at low frequency. In addition, UIoT transmissions suffer from high interference and collisions, which causes the low Packet Delivery Ratio (PDR), high End-to-End (E2E) delay, and reduction in energy efficiency. Furthermore, a considerable amount ofenergy is wasted in UIoT, if the void hole problem occurs. A void hole problem is a situation, in which the source node does not find an immediate forwarder node. Therefore, providing a reliable communication in the UIoT with enhanced network lifetime is highly desirable. Thus, in this paper, we propose a proactive Energy efficient Layer-by-Layer Watchman based Collision Free Routing (ELW-CFR) scheme that supports reliable and collision-free communications in UIoT environment with minimum energy wastage. Moreover, the proposed scheme provides the low E2E delay, and high PDR while avoiding the void hole problem. Extensive simulation has been performed to show the performance superiority of the proposed scheme against the state-of-the-art schemes.
... The low propagation speed results in high delay. Underwater propagation speed is almost 1500 m/s or essentially 5 times less than the radio waves [2,4]. Underwater nodes face high mobility that results in network topology instability. ...
... Underwater wireless sensor networks (UWSN) elicit considerable attention in academic, research, and industrial fields. Reduction of energy depletion of sensor nodes improves the network life of UWSNs, which in turn decreases the overall network cost [4,6], because several applications, such as coastline observation and assurance, sea calamity anticipation, observation of underwater contamination, military protection, and route assistance, and checking the marine oceanic environment and underwater asset investigation, are applied in this domain [1,4]. The probability of creating void holes is significantly reduced, whereas transmission reliability and end-to-end delay are improved effectively [4,8]. ...
... Underwater wireless sensor networks (UWSN) elicit considerable attention in academic, research, and industrial fields. Reduction of energy depletion of sensor nodes improves the network life of UWSNs, which in turn decreases the overall network cost [4,6], because several applications, such as coastline observation and assurance, sea calamity anticipation, observation of underwater contamination, military protection, and route assistance, and checking the marine oceanic environment and underwater asset investigation, are applied in this domain [1,4]. The probability of creating void holes is significantly reduced, whereas transmission reliability and end-to-end delay are improved effectively [4,8]. ...
Underwater acoustic sensor network (UASN) refers to a procedure that promotes a broad spectrum of aquatic applications. UASNs can be practically applied in seismic checking, ocean mine identification, resource exploration, pollution checking, and disaster avoidance. UASN confronts many difficulties and issues, such as low bandwidth, node movements, propagation delay, 3D arrangement, energy limitation, and high-cost production and arrangement costs caused by antagonistic underwater situations. Underwater wireless sensor networks (UWSNs) are considered a major issue being encountered in energy management because of the limited battery power of their nodes. Moreover, the harsh underwater environment requires vendors to design and deploy energy-hungry devices to fulfil the communication requirements and maintain an acceptable quality of service. Moreover, increased transmission power levels result in higher channel interference, thereby increasing packet loss. Considering the facts mentioned above, this research presents a controlled transmission power-based sparsity-aware energy-efficient clustering in UWSNs. The contributions of this technique is threefold. First, it uses the adaptive power control mechanism to utilize the sensor nodes’ battery and reduce channel interference effectively. Second, thresholds are defined to ensure successful communication. Third, clustering can be implemented in dense areas to decrease the repetitive transmission that ultimately affects the energy consumption of nodes and interference significantly. Additionally, mobile sinks are deployed to gather information locally to achieve the previously mentioned benefits. The suggested protocol is meticulously examined through extensive simulations and is validated through comparison with other advanced UWSN strategies. Findings show that the suggested protocol outperforms other procedures in terms of network lifetime and packet delivery ratio.
... Haitao Yu et al. [19] proposed a term of deferral and PDR. Stochastic execution examination with unwavering quality and collaboration (SPARCO) for UWSNs. ...
... Nonetheless, these steering conventions are not as proficient as required. It merits referencing that we have taken our inspiration from the Adaptive Hop by Hop Vector-Based Forwarding (AHH-VBF) plot [19,29]. It is an area mindful directing conventions and utilizations the versatile virtual pipeline idea. ...
... α(f) is the assimilation coefficient. The above condition has been additionally utilized by [10,19] ...
Underwater Wireless Sensor Network (UWSN) accomplishes the consideration of a few scientists and academicians towards itself. Because of the brutality of the climate lies submerged represents various difficulties, i.e., high transmission delay, outstanding piece mistake rate, more expense in usage, sinks development and energy imperatives, unequal surface highlights of an area and low data transfer capacity, and so forth Void opening evasion is compulsory for to motivation behind limiting the utilization of energy and amplifying throughput and region inclusion. In this exploration work, the creator planned plans for void opening shirking initial one is, Avoiding Void Hole Adaptive Hop by Hop Vector-Based Forwarding (AVH-AHH-VBF) in submerged remote sensor organization and a second plan for limiting utilization of energy and expanding the lifetime of the organization, Sink Mobility-Adaptive Hop by Hop Vector-Based Forwarding (SM-AHH-VBF). Reproduction results show that our plans beat contrasted and standard arrangement as far as normal Packet Delivery Ratio (PDR), energy charge. Our reproduction confirms the effectiveness of our proposed procedure AVH-AHH-VBF equivalents to 0.17 and SM-AHH-VBF equivalents to 0.24 regarding normal PDR, AVH-AHH-VBF equivalents to 24j and SM-AHH-VBF equivalents to 5j for the normal energy charge, AVH-AHH-VBF had a tradeoff of 63% in light of considering two jumps and SM-AHH-VBF approaches 20% tradeoff for normal start to finish.
... There are various vector and geographic-based routing schemes, for example, VBF [7], HH-VBF [21], AHH-VBF [22] and CVBF [23], in which only those nodes will take part in the transmission process that is within the virtual pipeline directed towards the single surface sink. No solution is however provided to balance the energy consumption of the forwarding nodes. ...
... Topology of the nodes Random [14], [22], [23] 7 ...
... Transmission Power 90 dB re Pa [22], [40] 12 Initial energy 100 J [14], [20] 13 Power consumption to transmit packet 2 units [21], [23] 14 ...
... A typical solution is to use a swarm of mobile sensors to construct observation systems [3]- [6]. Generally, mobile nodes are sparsely deployed over a large area due to their high design cost and high manufacturing cost [7], [8]. The information of each sensor node is transmitted to the sink node through multihop transmission and then forwarded to the onshore center via RF transmission. ...
... On the basis of VBF, hopby-hop vector-based forwarding (HH-VBF) optimizes the candidate set by adjusting the pipeline toward the sink node [23]. Adaptive hop-by-hop vector-based forwarding (AHH-VBF) resolves the redundant transmission problem in an underwater sparse network by dynamically adjusting each forward region [8]. Geographic and opportunistic routing with depth adjustment-based topology control for communication recovery over void regions (GEDAR) uses the 3D location of each node for selecting a candidate set and for estimating link reliability to select the optimal forwarder [10]. ...
... otherwise. (8) where N L , N S and N H are the numbers of neighboring nodes from subsets L, S, and H, respectively. hc p is the hop count carried in the packet. ...
In underwater wireless sensor networks (UWSNs), the sensor nodes are sparsely deployed over a large sea area due to their high design cost and high manufacturing cost. Opportunistic routing protocols are a promising forwarding technique for various UWSNs. However, many opportunistic routing protocols suffer from the void problem in sparse underwater scenarios. Hop count-based opportunistic routing protocols inherently alleviate this problem by periodically maintaining the topological information of sensor node. Nevertheless, the robustness of these protocols degrades due to channel variation and node movement in UWSNs. In this paper, we propose a coding-aware opportunistic routing method for sparse UWSNs (CORS). In CORS, we use topological information to adaptively expand the candidate set. On this basis, a forwarding with opportunistic coding strategy is developed to join interflow network coding and opportunistic forwarding in CORS. In addition, we design a sliding window-based coding algorithm to provide effective coding gains with low coding overhead. Then, a sliding window-based decoding algorithm is designed to reduce decoding overhead. Simulation results show that CORS significantly improves upon the network performances of existing protocols in various scenarios.
... There are numerous vector and geo-opportunistic based routing protocols, for example, VBF by Xie et al. [10], HH-VBF by Nicolaou et al. [28], AHH-VBF by Yu et al. [29] and CVBF by Ibrahim et al. [39], in which only those nodes will contribute in the packet transmission that exists within the virtual pipeline, and directed towards the surface sink. No any mechanism is utilized by those protocols to balance the energy utilization of the forwarding node. ...
... By using above Thorp model, the a(f) in dB/km formulation is given below [43], likewise in [29]: ...
... The behavior of our scheme is considered to be hybrid in terms of mobility (i.e., anchor nodes are fixed and relay nodes can move in 2D random direction concerning water waves). Relay nodes are supposed to remain inside the network region, for which we use RandomWalk 2D mobility model as used in [29], [36]. As per this model, the relay nodes can have random walk in 2D direction (X-Y plane) with a speed of 2m/sec to 4m/sec. ...
Underwater Sensor Network (UWSN) is gaining popularity among researchers due to its peculiar features. But there are so many challenges in the design of the UWSN system, and these are quite unsustainable due to the dynamic nature of water waves. Perhaps the most tedious challenge for UWSNs is how to transfer the data at the destination with a minimal energy rate. It can be accomplished by exploiting geographic and opportunistic routing schemes to send the data efficiently to the surface sinks in cooperation with relay nodes. With this aim, we introduce a new protocol for routing, named Geographic and Cooperative Opportunistic Routing Protocol (GCORP). In GCORP, the packets are routed from the source node to the surface sinks in coordination with intermediate relay nodes. In GCORP protocol, initially, multiple sinks-based network architecture is established. Then, a relay forwarding set is being determined by the source node on the basis of depth fitness factor. Finally, the best relay is determined through the weight calculation scheme from the relay forwarding set. We conduct the simulations in NS3 to validate the proposed GCORP routing protocol concerning different network metrics. The simulations conclude that the GCORP protocol shows better performance than existing approaches.
... Here: -R represents range of communication (m) and k represents spread factor, k denotes propagation geometry for acoustic signals. Usually applied to spread factor values are k = 1 for the cylindrical spreading, k = 2 for the spherical spreading and k = 1.50 in the practical spreading [20,21] ...
... = √0⋅3240 * 10 -5 * V w 5 (20) Where Vw represents velocity of the wind (m/s). In terms of intensity, measured in decibels, the surface losses would: ...
Tigris River is an environment of shallow waters because of its low depth and it has been identified as a multi-path channel. The underwater multi-path propagation leads to reverberation as well as fading, which causes large transmission loss. The present paper conducts 3 underwater acoustic simulation outcomes in the district of Abu Dali - Kazem Al Ali village - Tigris beaches - Baghdad - Iraq. The distance from the sender to the receiver are (100m, 1000 m, and 5000m). With the use Ray model, results have shown that the multi-path propagations dominate in a case where the distance from sender to receiver, has been increased, which resulted in decreasing the grazing angle, thereby, increasing the coefficient of reflection. The consecutive path amplitude values will not be decreased quickly. This is why differences in the time between different paths are minimal. This indicates that the consecutive path-ways will be converged with time, which will result in an inter- symbol interference phenomenon, playing a role in an increase of the received data bit error rate.
... The protocol does not have the functionality to re-transmit the packet, if the sensor node does not receives it due to weak received signal strength, or collision problem [20], due to the limited stored battery power of the devices, the Copyright © 2022 MECS I.J. Wireless and Microwave Technologies, 2022, 3, 33-53 sensor nodes that are frequently qualified to forward data packet can be easily exhausted and failed [21], the number of forwarding node are limited due to the routing pipeline radius, and more efficient path can exists outside the pipeline that leads to the sink node, hence the routing performance can be severally affected [21], in addition VBF suffers from void holes as the sensor nodes are deployed in a large environment, the void holes are the sensor nodes with no path leading to the next destination or forwarder node, that causes an important loss of data packet [22], When the sensor nodes forward their data packets, they does not takes into account the efficiency and quality of link with the next hop nodes, that generates at some point unnecessary transmission [23]. ...
... x=t PT is the predicted time. Where the predict time t pt = t 1 + M t , and M t is the average value of the measurement [22] calculated as follow : ...
In those last decades the Underwater Wireless Sensor Network (UWSNs) have become the commonly explored technology by the scientific community, for the numerous benefits that it can brings to the researchers, however the frequent movement of the underwater sensors due to their mobility or water current factor may severally affect the efficiency of the acoustic wireless communication and reduce it performance. In this paper a Mobility Aware Strategy for Geographical Routing scheme (MAGR-VBF) has been proposed for an early prevention from the mobile sensor during the packet transmission, the protocol is aimed to predict the mobility and switch to another candidate sensor enable to recover the data packet in order to mitigate the packet loss problem. Based on the well-known routing protocol for the UWSNs 'Vector Based Forwarding' (VBF) the proposed study has been implemented and designed using the NS-2 simulator and Aqua-Sim. The result has shown that the presented work (MAGR-VBF) has brings a good performance over the basic VBF, where the energy consumption and the average end to end delay have been reduced by 8.97 % and 5.55 % respectively, and an average of 6.16 % has been increased of packet delivery ratio metric.
... These void handling algorithms are further divided into location-based and pressure-based. Some examples of locationbased void handling algorithms are AHH-VBF [48], RMTG [49], and MRP [50]. While, some examples of pressure-based void handling algorithms are HydroCast [51], LLSR [52], and OVAR [53]. ...
... The nodes may become far from the virtual routing pipes because of continuous node movement, resulting in dropping the packets to affect the packet delivery ratio. Yu et al. [48] proposed an AHH-VBF routing protocol for UWSN. This protocol is proposed to reduce the shortcomings and enhances the performance of HH-VBF. ...
Underwater wireless sensor network (UWSN) is a new technology that can be used for various purposes, including ocean tracking and underwater exploration, military surveillance, disaster management, industrial applications, and scientific research. These applications require the sensed data to be routed to the destination, and this results in making the data routing one of the essential parts in designing such applications. High propagation delay, restricted bandwidth, 3D deployment, and energy constraints are some of the challenges that UWSN faces when developing routing protocols. Therefore, to mitigate these challenges, efficient routing protocols are proposed according to the specific application. This paper surveys recently routing protocols for UWSN. Furthermore, each routing protocol's main idea and essential operation are presented and its merits and demerits. There are two types of routing protocols surveyed: location-based and location-free routing protocols. Each type is divided into two sub-categories: those that take into account node mobility and those that do not. The surveyed protocols are evaluated through the analytical method in which these protocols are compared through a wide range of parameters like packet delivery ratio, end-to-end delay, energy efficiency, and reliability. Some of the surveyed protocols are evaluated through the numerical simulation method by using Aqua-Sim with NS2.30 and are compared through packet delivery ratio, end-to-end delay, and energy consumption. This survey's core goal is to encourage more research into improving UWSN routing protocols for better underwater exploration and monitoring.
... After searching, the forwarder tends to choose paths with a minimal amount of zigzagging, that is, those paths with minimum deviation from the straight line between source and destination. The transmission power level in AHH-VBF [91] can also be increased to cover a larger range in sparse networks or decreased to save more energy in dense networks. These two protocols designed rely on the location of neighbors and destination, which is costly in some high dynamic underwater environments. ...
... However, in the anycast protocol, forwarding eligibility must be determined and holding time must be calculated at the receiver to prevent this from happening. Another way to reduce forwarding participants is the flooding routing protocol [88], [89], [90], [91], which controls the flooding region to prevent the involvement of additional relay nodes as shown above. ...
Reliable data collection techniques, whose aim is to ensure that sensed data are received successfully by a sink, are essential for applications in Underwater Wireless Sensor Networks (UWSNs). However, traditional data collection with Radio Frequency (RF) functions poorly in UWSNs due to peculiar features of underwater. Moreover, acoustic communication creates challenges for the reliability of data collection such as high bit error rate, packet collision and voids in routing. Furthermore, the deployment of Autonomous Underwater Vehicles (AUVs) in some scenarios changed the paradigm of data collection and introduced new issues that affect reliability such as inaccurate navigation and lengthy travel time. Consequently, numerous studies focus on the relative reliability of various currently available data collection in UWSNs. In this paper, we first review the problems specific to UWSNs and their impact on reliable data collection. It is followed by a discussion about characteristics, challenges, and features associated with the design of reliable techniques in UWSNs. Afterward, to provide readers with an overview of reliable data collection techniques in UWSNs, this paper categorizes them according to their ability to enhance reliability at all the key stages of data collection. In this categorization framework, the advantages and disadvantages of each technique have been in-depth discussed. Finally, several possible areas for further research are identified and discussed.
... The proposed technique schedules the broadcast process and also reduces the high latency. Yu et al. (2015) propose a forwarding technique, which is unlike to vector-based forwarding (VBF), the transmission radius of virtual pipeline and transmission power levels are adjusted at each hop in AHH-VBF. It improves network reliability by adaptively adjusting the transmission radius in case of locally sparse and dense node distributions to avoid the void holes. ...
... When a most recent beacon message is received, the entry is refreshed on the basis of sequence number. To minimise the collisions, the periodic beaconing proves to be useful than the flooding mechanism of control messages (Yu et al., 2015). Every node checks its sequence number when they receive beacon message and if it is greater than the earlier received beacon then it updates its entries of the reachable sinks. ...
Localization of sensors in Underwater Internet of Things (UIoTs) is difficult due to the mobility. This changing makes the routing decisions difficult, which results in unreliable communication. This paper proposes Adaptive Transmission based Geographic and Opportunistic Routing (ATGOR) protocol for reliable communication between nodes. ATGOR operates in two parts: election of a small cube to avoid redundant transmissions and selection of reliable nodes which forward data from the selected small cube for optimal transmissions. Furthermore, to guarantee the reliability of the data packets in a harsh acoustic environment, we propose Mobility Aware ATGOR (MA-ATGOR), which predicts the locations of neighboring sensor nodes for successful data delivery. In addition, prediction of tthe locations of the sensor nodes helps in avoiding the void holes along with high packet delivery. The performance of the proposed routing protocols is validated based on the PDR, number of void nodes and energy consumption per packet, through simulations.
... The path loss can be approximated using Thorp's model [39,41,42]. More specifically, the Thorp's model is used to design the propagation of underwater acoustic communications, and to adjust the transmission power [41,[43][44][45][46]. A lossy channel and the bit error rate depend on the signal frequency and traversed distance. ...
... To obtain the received signal without failure, the SNR at the destination should be greater than a detection threshold. The ambient noise in the aquatic environment contains four essential components of turbulence PN t ( f ), shipping PN s ( f ), waves PN w ( f ), and thermal energy PN th ( f ), which can be calculated as [43]: ...
The Medium Access Control (MAC) layer protocol is the most important part of any network, and is considered to be a fundamental protocol that aids in enhancing the performance of networks and communications. However, the MAC protocol’s design for underwater sensor networks (UWSNs) has introduced various challenges. This is due to long underwater acoustic propagation delay, high mobility, low available bandwidth, and high error probability. These unique acoustic channel characteristics make contention-based MAC protocols significantly more expensive than other protocol contentions. Therefore, re-transmission and collisions should effectively be managed at the MAC layer to decrease the energy cost and to enhance the network’s throughput. Consequently, handshake-based and random access-based MAC protocols do not perform as efficiently as their achieved performance in terrestrial networks. To tackle this complicated problem, this paper surveys the current collision-free MAC protocols proposed in the literature for UWSNs. We first review the unique characteristic of underwater sensor networks and its negative impact on the MAC layer. It is then followed by a discussion about the problem definition, challenges, and features associated with the design of MAC protocols in UWANs. Afterwards, currently available collision-free MAC design strategies in UWSNs are classified and investigated. The advantages and disadvantages of each design strategy along with the recent advances are then presented. Finally, we present a qualitative comparison of these strategies and also discuss some possible future directions.
... Henceforth, due to the dynamic nature of water waves, the nodes are prone to move in a random direction. For nodes mobility, we apply a 2D RandomWalk mobility model with a speed of 1-3 m/s [46], [56]. According to this, nodes can move horizontally in a 2D manner. ...
... for j = 0 to T sim with respect to T m do 5 Node N i has coordinates (x i , y i , z i ) 6 Network N S has coordinates (X , Y, Z) . For the mobility of the nodes, we used RandomWalk 2D mobility model as used in [46], [56]. ...
Reliable data transfer seems a quite challenging task in Underwater Wireless Sensor Networks (UWSN) in comparison with Terrestrial Wireless Sensor Networks due to the peculiar attributes of UWSN communication. However, the reliable data transmission in UWSN is very limited. Yet, there is a way to achieve reliable data transfer metrics through the design of routing protocols by considering the exceptional features of UWSN communications. With this aim, we propose two schemes with multiple sinks-based network architecture: Anchor Nodes assisted Cluster-based Routing Protocol (ANCRP) to achieve reliable data transfer metrics and Void Handling technique in ANCRP (VH-ANCRP) to cope with the local maximum nodes. For which, the network space is divided into small cubes to form clusters. Then, each cube is assigned with an anchor node as a cluster head (CH). All cluster heads are supposed to be anchored at the centroid of a cube via a string, while source nodes are randomly distributed. In ANCRP, the source nodes are liable to send the sensed data to their designated CH. The CH transmits the sensed data to the next-hop CH and continues this procedure till the successful delivery of the data packets at the surface sinks. In VH-ANCRP, a void handling technique of making the ad-hoc CH is used by the void nodes to reconnect with the network operations. We perform extensive simulations in NS3 to validate our schemes. The simulation outcomes expel that both proposed schemes have improved the network performance when compared with the baseline schemes.
... Three-dimensional-based protocols [9][10][11][12] can find a geographically ideal path for a source node, but the challenge is to achieve a balance between extending network lifetime and shortening end-to-end latency. Some routing protocols based on location information give priority to nodes closer to the destination node when selecting forwarding nodes, which shortens the lifetime of the network. ...
... However, because there were more routing pipes in the network, it also increased the network load, and the performance of HH-VBF was closely related to the pipe radius. In an adaptive hop-by-hop vector-based forwarding routing protocol (AHH-VBF) [11], the radius of the virtue pipe and the transmission power level are adaptively changed hop-by-hop, so both the delivery ratio and the energy efficiency can be optimised in this protocol. In addition, it also reduces the end-toend delays by selecting the forwarding nodes with consideration of the distance from the local to the sink node. ...
Research on underwater acoustic sensor networks has become a compelling field in recent years since resources on land are being depleted. Therefore, robust and efficient routing protocols are needed to ensure the reliability of message gathering and transmitting in underwater sensor networks. In the process of biological foraging in nature, creatures such as insects can find paths while adapting to dynamic environmental conditions through group cooperation, which provides a new perspective for research on routing protocols. In this study, the authors proposed an ant colony algorithm-based routing protocol (ACAR). In ACAR, the pheromone with a novel physical meaning and concentration changing mechanism is utilised to guide ants (path establishing packets) to the sink node. In addition, node depth information is used to decrease redundancy in the underwater environment. The routing process can be summarised in three parts: Pheromone list setup, routing decision and damaged path repair. Simulation results, carried out on an underwater simulator based on NS-2, showed that ACAR outperforms other schemes with regards to network lifetime with a relatively better delivery ratio and latency in the proposed network scenarios.
... In an environment with saturated nodes, controls system flooding to minimize energy loss brought on by a high density of data relay nodes. In contrast, the authors of [12] and [13] used the concept of an adaptive pipeline to advance data packets, ensuring the reliability of the data packets' conveyance in the limited system. ...
Due to their limited frequency range and fast fading channels, underwater sensor networks (USNs) are vulnerable to collisions of packets. In this paper, we propose a deep reinforcement learning-based relay selection scheme with shortest latency (DRL-SL) for USNs that enables to choose the relay based on the state that comprised of the bit error rate (BER) of the previous transmission, and the jamming power measured by the relay node. The DRL-SL-based relay selection scheme completed in two phases. In the first phase, a deep neural network based learning is performed and second phase is the real-time interaction with the underwater sensor network. Numerical results give the bound on how efficiently the system performs in terms of bit error rate, energy use, and node utility. According to the numerical results, the proposed DRL-SL based relay selection scheme can enhance relay performance in comparison to the benchmark underwater relay techniques.
... The Signal to Noise Ratio (SNR) spanning a single frequency f and a distance of d irj is so calculated as where E b is the average energy used during the broadcast of a bit and N T (f ) is the average power density of noise in an acoustic channel. UWSNs have four primary sources of noise: turbulence N t (f ) , as specified in [35]: ...
The term "Underwater Internet of Things" (UIoT) refers to a system of intelligent, networked devices that may function in a variety of water conditions. During communication, the transmission quality is diminished by high levels of interference and collisions, which in turn causes a slow End-to-End (E2E), low latency, and a low Packet Delivery Ratio (PDR). And when the basis node does not choose an immediate forwarder node, an issue known as the "void hole" occurs and thus leads to the wastage of more power. Despite playing a crucial role in enabling underwater communication, IoUT frameworks still face difficulties because of their unstable radio signals, low resources, unreliable transmission medium, low bandwidth, limited range, low transmission rate, inborn noise, node mobility, slow propagation speed, and limited battery capacity. Therefore, it is greatly desirable to have secure communication with a prolonged network lifetime. In this research work, an opportunistic routing-based reliable transmission protocol (OR-RTP) is proposed to send the packs toward the superficial sink to lessen the high energy consumption (EC). The source node recognizes the furtherance relay set in the proposed protocol based on the forwarder's local information. The proposed protocol uses a meta-heuristic-based relay selection scheme (Artificial rabbits’ optimization-ARO) to pick the best relay by balancing the forwarder's EC and packet delivery ratio (PDR). During packet transmission, most of the energy is ruined because of collisions among Under Water Acoustic Sensor Networks (UW-ASNs') sensor nodes. This work developed an RTP for every forwarder node that sends data to the surface basin to reduce the problem of collision. The OR-RTP protocol has been extensively simulated, and the results are compared to those of other routing protocols in terms of EC, PDR, throughput, and network lifetime. The proposed model achieved 85% of PDR on 400 nodes and 92% of PDR for 700 nodes, whereas the existing model Grey Wolf Optimization achieved 51% of PDR on 400 nodes and 73% of PDR for 700 nodes.
... Hop-by-hop virtual pipe method results in significant communication overhead. In AHH-VBF, the pipeline's radius is adaptively modified at each hop during packet transmission to save energy [18]. The DFR uses directional flooding [12] to save a large amount of energy. ...
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.
... UWSN routing is crucial for enabling underwater applications as it facilitates the transmission of information and data among underwater nodes. However, UWSN routing faces significant differences and poses additional challenges compared to terrestrial wireless sensor networks [3][4][5]. On one hand, underwater networks require a higher level of energy balance among nodes, as underwater nodes cannot replenish their energy and have limited energy storage. If a node is excessively utilized, it may become ineffective due to premature energy depletion. ...
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.
... Numerous publications have presented representations for a submerged auditory connection that takes into account hooked-on interpretation variables, similar to salinity: hotness, complexity, and meddling from the environment, to name a few. Other physical ocean factors, such as medium noise, thermal noise, wind, turmoil, and ship noise, are also taken into consideration in these calculations, depending on the frequency and the following variables [42][43][44]: ...
Oceanographic data collection, disaster prevention, aided navigation, critical observation sub-missions, contaminant screening, and seaward scanning are just a few of the submissions that use underwater sensor hubs. Unmanned submerged vehicles (USVs) or autonomous acoustic underwater vehicles (AUVs) through sensors would similarly be able to explore unique underwater resources and gather data when utilized in conjunction with integrated screen operations. The most advanced technological method of oceanic observation is wireless information routing beneath the ocean or generally underwater. Water bottoms are typically observed using oceanographic sensors that collect data at certain ocean zones. Most research on UWSNs focuses on physical levels, even though the localization level, such as guiding processes, is a more recent zone. Analyzing the presenting metrics of the current direction conventions for UWSNs is crucial for considering additional enhancements in a procedure employing underwater wireless sensor networks for locating sensors (UWSNs). Due to their severely constrained propagation, radio frequency (RF) transmissions are inappropriate for underwater environments. This makes it difficult to maintain network connectivity and localization. This provided a plan for employing adequate reliability and improved communication and is used to locate the node exactly using a variety of methods. In order to minimize inaccuracies, specific techniques are utilized to calculate the distance to the destination. It has a variety of qualities, such as limited bandwidth, high latency, low energy, and a high error probability. Both nodes enable technical professionals stationed on land to communicate data from the chosen oceanic zones rapidly. This study investigates the significance, uses, network architecture, requirements, and difficulties of undersea sensors.
... However, nodes that are within the routing pipe are used more frequently than those outside, which results in an unbalanced energy consumption and reduced network lifetime. To address this issue, hop-by-hop vector-based forwarding [6] and adaptive hop-by-hop vector-based forwarding [7] protocols have been proposed. These protocols offer a shorter delay than VBF but at the expense of a higher overhead. ...
In this paper, an energy-efficient Q-learning-based routing protocol, called the Q-learning-based topology-aware routing (QTAR) protocol, is proposed for underwater wireless sensor networks. Unlike existing protocols, QTAR considers the network topology to determine the next-forwarder (NF) candidates along the routing path and adopts Q-learning to aid in the optimal global decision-making of an NF from the NF candidates. In addition, QTAR utilizes implicit cut-vertex recognition to optimize NF selection, alleviating the energy wastage that arises from forwarding data packets away from the sink. In our study, we evaluated the performance of QTAR by comparing it with the Q-learning-based energy-efficient and lifetime-aware routing protocol (QELAR), energy-efficient depth-based routing protocol (EEDBR), Q-learning-based delay-aware routing (QDAR), and reinforcement learning-based opportunistic routing protocol (RLOR) in terms of the energy consumption, latency, and network lifetime. Our results revealed that QTAR demonstrated the advantages of a lower energy consumption, shorter latency, and longer network lifetime in the percentage ranges of 26.08 to 70.12, 22.2 to 50, and 37.8 to 75, respectively, than QELAR, EEDBR, QDAR, and RLOR.
... Because of the liquidity feature of the underwater territory, the routing in UWSNs has certain difficulties [4][5][6][7]. The underwater wireless communication route suffers from significant signal losses [8] and the complicated multipath effect [9] results in a higher bit error in communication with restricted bandwidth for underwater audio communication [10]. ...
The submarine detection is the most significant research area of Under Water Acoustic (UWA) environment with extensive application in commercial and navy domains. The environmental complexity and variable nature of the UWA makes Underwater Wireless Sensor Network (UWSN) to exhibit fluidity, sparse deployment, time unpredictability, frequency selectivity, limited accessible bandwidth and energy constraints pose problems in the underwater positioning technology. Thus, an adaptable, scalable, and highly efficient UWA is required for the submarine routing systems. The depth-based routing has received lots of interest as it is capable of delivering effective operation without requiring full-dimensional position information of nodes. However, it has issues of vacant regions and detouring forwards. To delineate the aforementioned problems, this paper proposes an Opportunity-based Distance Vector Routing (ODVR) technique. The distance vectors, which have lowest hop counts in the direction of sink for underwater sensor nodes are determined by ODVR through a query method. Depending on the distance vectors, a dynamic routing is created to manage the packet forwarding. In the opportunistic forwarding, the ODVR has a minimal signaling cost and minimum energy consumption with the potential of eliminating the long detours issues. The outcomes of simulations demonstrate that the ODVR outperforms the conventional routing algorithms.
... In HH-VBF, the distribution of energy is not fair at each forwarding node in the network, as at each hop, the pipeline created is of the same radius and expansion, and does not consider the distribution of the sensor nodes in a network. Thus, the shortcomings in HH-VBF are covered by the Adaptive Hope-by-Hope Vector-Based Forwarding (AHH-VBF) [14]. The basis of AHH-VBF is HH-VBF, which also creates a virtual pipeline at each hop, but as we know, in UASN, the sensors nodes are distributed randomly, as in some local regions the density of the sensor nodes is low, called sparse sensors regions, and in some regions, the density of the nodes are high, called dense regions of the network. ...
There exist numerous applications for deploying Underwater Wireless Sensor Networks (UWSNs), including submarine detection, disaster prevention, oil and gas monitoring, off-shore exploration, and military target tracking. The acoustic sensor nodes are deployed to monitor the underwater environment, considering the area under observation. This research work proposes an energy scarcity-aware routing protocol for energy efficient UWSNs. Moreover, it aims to find the feasible region on the basis of the objective function, in order to minimize the energy tax and extend the network life. There are three different sensors nodes in the network environment, i.e., anchor nodes, relay nodes, and the centralized station. Anchor nodes originate data packets, while relay nodes process them and broadcast between each other until the packets reach the centralized station. The underline base scheme Weighting Depth and Forwarding Area Division Depth-Based Routing (WDFAD-DBR) for routing is based on the depth differences of the first- and second-hop nodes of the source node. The propose work, Betta and Dolphin Pods Routing via Energy Scarcity Aware protocol (BDREA) for packet forwarding from the forwarding nodes considers the first and second hops of the source node, i.e., the packet advancement, the network traffic, the distance to the centralized station, and the inverse normalized energy of the forwarding zone. It is observed that the proposed work improves the performance parameters by approximately 50% in terms of energy efficiency, and prolongs the network life compared to Dolphin and Whale Pod (DOW-PR) protocols. Furthermore, the energy efficiency directly relates to the other parameters, and its enhancement can be seen in terms of an 18.02% reduction in end-to-end delay when compared with the Weighting Depth and Forwarding Area Division Depth-Based Routing (WDFAD-DBR) protocol. Furthermore, BDREA improves the Packet Delivery Ratio (PDR) by approximately 8.71%, compared to DOW-PR, and by 10% compared with the benchmark, WDFAD-DBR, the energy tax by 50% in comparison to DOW-PR, the end-to-end delay by 18%, and the APD by 5% in comparison to WDFAD-DBR.
... Thus, there would be 18 CHs, and 400 source nodes in the network region . A RandomWalk mobility model is utilized to control the nodes' mobility [38,39]. A LinkQuest UWM1000 [36] UASN modem is used to set various other simulation parameters. ...
Exhaust research work has been carried out in the field of Terrestrial Wireless Sensor Networks (TWSN). Now, research penetration is moving toward Underwater Acoustic Sensor Networks (UASNs). The communication of UASNs has dependencies on acoustic instead of radio. Efficient data collection by the UASN seems a tedious job in comparison with TWSN due to the peculiar features of underwater communication. However, there is a way to accomplish efficient data collection metrics through the design of routing protocols by considering the unique features of UASN communications. In this context, we propose a novel scheme and we call it Floating Nodes assisted Cluster-Based Routing (FNCBR) scheme for efficient data collection in UASNs. In FNCBR, the network space is divided into cuboids to form clusters. Then, every cuboid is consigned with a floating node (FN) at the surface layer and two fixed cluster heads (CHs) are suspended at different depth levels. All CHs of cuboids are supposed to be connected with a floating node via a wired connection, while source nodes are haphazardly distributed in the whole network region. In FNCBR, source nodes are liable to send the sensed data either to the FN or to the nearest CH. The data collected by the CHs is moved towards the FNs, which further disseminate the data to the on-shore monitoring center via a Radio Frequency (RF) link. We conduct the simulations in Network Simulator (NS-3) to appraise the proposed FNCBR protocol with other clustering protocols (e.g., CVBF, BS-CVBF, and ANCRP) in terms of different performance metrics. After describing the results, a quantitative comparison table is also given. The FNCBR scheme is also evaluated in terms of multiple FN densities. The simulation outcomes justify that the proposed FNCBR scheme has given better results in all performance metrics than the baseline schemes.
... The relay nodes ranging from 100 to 550 are randomly distributed in the network region. We employed the RandomWalk 2D mobility model, which is similar to the one used [52,39], and allows nodes to move in a 2D way at a pace of 1-3m/s, which also affects the network deployment [53]. The vertical transitions of the nodes are insignificant and can be overlooked [54,55]. ...
Internet of Underwater Things (IoUTs) deals in a resource-constrained environment and has several open issues, challenges, and potential applications in both onshore and offshore fields. The distinctive features of acoustic medium and persistent node mobility have spurred the development of a routing protocol for IoUT that ensures the efficient data transfer at the surface station. The efficient data transfer metrics can be achieved either by the emergence of cluster-based or chain-based routing protocols. This paper provides a simulation-based quantitative analysis of the most recent and prominent cluster-based and chain-based routing protocols for IoUT that are intended to enable the efficient data transfer from source to destination. In this context, we use NS3 to conduct extensive simulations for the quantitative analysis of different routing protocols relating to packet delivery rate, packet drop rate, normalized energy consumption, normalized network lifetime, density of alive nodes, and density of dead nodes. In addition to quantitative analysis, we also provide the performance trade-offs, limitations, and applications for IoUT routing protocols for these two classifications. In last, we also perform quantitative analysis for these two classifications head-to-head. This work aims to provide helpful insights into selecting a suitable protocol for routing applications to meet the various specifications and requirements of IoUT for efficient data dissemination.
... the same distance to the destination, all nodes will forward the same packets and this will generate a high rate of collisions [86]. ...
Routing is one of the most challenging task in mobile ad hoc networks. Several works have been proposed to address this challenge. Majority numbers of researchers have introduced the routing protocols based on minimize resource consumption but still research needs improvement to design the efficient routing protocols which control the node movement. Proper use of location information and dynamically adjustment of intermediate nodes’ retransmission adopted by a number of algorithms contribute to a reduction in the number of retransmissions and consequently reduce control overhead and resource consumption, but this feat was achieved at a price on network reachability. In this paper, an overview of analytical, network, and simulation model used in the design of routing mechanisms wherever possible is presented. This review paper classifies routing protocols into three categories named as route discovery, QoS (Quality of Service), and route maintenance with their relative performance. This paper also compares routing mechanisms against routing efficiency, reliability, packet delay, packet delivery ratio, control overheads, and QoS. This paper reviewed some current literatures that were proposed to improve the reliable, resource consumption, scalable, and QoS based routing mechanisms. This article also highlights the performance demands required of these protocols to assist researcher in MANET resource conservation as a good starting point for developing efficient routing algorithm.
... If the flooding angle is not suitable, the possibility of transferring data may cause failure, so it was not appropriate in the sparse areas. Yu et al. presented the AHH-VBF [29] protocol for sparse regions. In this protocol, the radius of the virtual pipeline is adaptively accommodated for packet broadcasting. ...
Data collection in underwater wireless sensor networks (UWSNs) using autonomous underwater vehicles (AUVs) is a more robust solution than traditional approaches, instead of transmitting data from each node to a destination node. However, the design of delay-aware and energy-efficient path planning for AUVs is one of the most crucial problems in collecting data for UWSNs. To reduce network delay and increase network lifetime, we proposed a novel reliable AUV-based data-collection routing protocol for UWSNs. The proposed protocol employs a route planning mechanism to collect data using AUVs. The sink node directs AUVs for data collection from sensor nodes to reduce energy consumption. First, sensor nodes are organized into clusters for better scalability, and then, these clusters are arranged into groups to assign an AUV to each group. Second, the traveling path for each AUV is crafted based on the Markov decision process (MDP) for the reliable collection of data. The simulation results affirm the effectiveness and efficiency of the proposed technique in terms of throughput, energy efficiency, delay, and reliability.
... In [16], authors proposed AHH-VBF, in which packets are restrictive to a fixed zone of transmission in a virtual pipeline between the current forwarding node and the destination. Whether a node forwards a packet depends on its relative location to the virtual pipe. ...
As a key enabling technology of underwater acoustic sensor networks, underwater routing feature a variety of unique characteristics, including limited energy supply, high end-to-end delay and low delivery ratio. All these problems pose challenges in the design of efficient and effective routing protocols. To address such challenges, we propose an adaptive multi-zone geographic routing protocol(AMGR). First, AMGR dynamically adjusts the neighbor information acquisition interval according to the topology change speed, which not only reduces the excessive energy consumption of updating information, but also improves the performance of routing in high dynamic underwater environment. Second, according to the characteristics of different forwarding zones, the multi-region cooperative forwarding mechanism is adaptive used to improve the end-to-end delay and increase delivery ratio under the premise of reducing energy consumption as much as possible. Third, in priority calculation, we consider both the impact of packet transmission advancement and energy consumption, which can ensure less hops and avoid some high advancement nodes running out of energy in advance. Simulation results show that the proposed protocol outperforms AHH-VBF, PCR and restrictive flooding in delivery ratio, end-to-end delay and energy tax.
... If the packet struck at the concave void, it initiates the back-pressure technique in which packets will move backward until it finds an eligible node that can forward the packet through the vector-shift mechanism. Adaptive Hop-by-Hop Vector-Based Forwarding (AHH-VBF) [12], is a location-based routing algorithm that requires its nodes must be aware of their one-hop neighbor through periodic beaconing. It handles the void-node problem by adjusting the direction and width of the pipe hop-to-hop basis until it finds a suitable forwarding node. ...
The field of Underwater Acoustic Sensor Networks (UASNs) is one of the emerging areas of communication due to the number of marine applications. However, UASNs face several fundamental challenges like node movement, high propagation delay, low throughput, high bit-error-rate, low bandwidth, and void-node during communication. Void-node during routing is one of the major problems during routing, which causes high end-to-end delay to route the packets to the sink. The void-node is a fundamental challenge in UASNs and directly influences the UASNs in terms of the end-to-end delay, packet loss, and reliability of the UASNs. The main objective of this paper is to design a void-aware routing protocol referred to as Location-Free Void Avoidance Routing (LFVAR) protocol. It develops void-awareness among nodes in the UASNs and prevents forwarding of the packets to void and trap nodes. Further, LFVAR capable of selecting the efficient void-recovery path for the void-nodes present in the UASNs. Thus, it aims at reducing the end-to-end delay, lower energy consumption, higher packet delivery ratio, and increasing throughput during routing. The LFVAR protocol is implemented in UnetStack and further compared with the state-of-the-art Interference-aware routing (Intar) protocol. The simulation result shows that the packets in LFVAR reach the sink 32.32 % faster, consumes 20.54 % lower energy, and 9.8 % higher packet delivery ratio than Intar.
... Therefore, in the proposed algorithms, immutable selection of forwarder nodes is performed using two parameters: energy of forwarder and total energy of neighbor nodes. Moreover, in case of void node occurrence, an adjacent node selection is adopted to find an alternate routing for successful network operation, which is different from [18], [19] and [20]. ...
The routing in underwater acoustic sensor networks (UASNs) has become a challenging issue due to several problems. First, in UASN, the distance between the nodes changes due to their mobility with the water current, thus increasing the network's energy consumption. Second problem in UASNs is the occurrence of the void hole, which affects the network's performance. Because nodes are unable to deliver data towards the destination due to the absence of forwarder nodes (FNs) in the network. Thus, the objective of routing in UASNs is to overcome the issues mentioned earlier to prolong the network's lifetime. Therefore, a Q-learning based energy-efficient and balanced data gathering (QL-EEBDG) routing protocol is proposed in this paper. In QL-EEBDG, the FNs are selected according to their residual energy and grouped according to their neighboring nodes' energies. Using energy as the main selection parameter assures efficient energy consumption in the network. Moreover, efficient selection of the FNs increases the lifetime of the network. However, the void node recovery process fails when the topology of the network is changed. Therefore, to avoid void holes in QL-EEBDG, a QL-EEBDG adjacent node (QL-EEBDG-ADN) scheme is proposed. It finds alternate neighbor routes for packet transmission and ensures continuous communication in the network. Extensive simulations are carried out for the performance evaluation of the proposed technique with existing baseline protocols, namely efficient balanced energy consumption based data gathering (EBDG), enhanced EBDG (EEBDG) and QELAR. The performance parameters used in the simulations are network lifetime, energy tax, network stability period and packet delivery ratio (PDR). The simulation results depict that the proposed QL-EEBDG-ADN outperforms the baseline protocols by approximately 11% better PDR and 25% better energy tax.
... Moreover, GEDAR resolves the void problem by adjusting the depth of each potential forwarder. Adaptive hop-byhop vector-based forwarding (AHHVBF) is developed based on typical VBF by adding the neighborhood table constructed in each node [27]. Moreover, a sender dynamically changes the pipe radius according to the feedback of neighbor nodes to bypass void region. ...
Underwater wireless sensor networks (UWSNs) have emerged as a promising technology to monitor and explore the oceans instead of traditional undersea wireline instruments. Traditional routing protocols are inefficient for UWSNs due to the specific nature of the underwater environment. In contrast, Opportunistic Routing (OR) protocols establish an online route for each transmission, which can well adapt with time-varying underwater channel. Cross-layer design is an effective approach to combine the metrics from different layers to optimize an OR routing in UWSNs. However, typical cross-layer OR routing protocols that are designed for UWSNs suffer from congestion problem at high traffic loads. In this paper, a Cross-Layer-Aided Opportunistic Routing Protocol (CLOR) is proposed to reduce the congestion in multi-hop sparse UWSNs. The CLOR consists of a negotiation phase and transmission phase. In the negotiation phase, the cross-layer information in fuzzy logic is utilized to attain an optimal forwarder node. In the transmission phase, to improve the transmission performance, a burst transmission strategy with network coding is exploited. Finally, we perform simulations of the proposed CLOR protocol in a specific sea region. Simulation results show that CLOR significantly improves the network performances at various traffic rates compared to existing protocols.
... However, the HH virtual pipe approach creates significant contact overheads compared to VBF and lacks a mechanism to avoid the void space. • AHH-VBF: The Adaptive Hop-by-Hop Routing Protocol (AHH-VBF) [6] is another attempt to improve the VBF and HH-VBF protocols. It uses variable transmission ranges to save network resources. ...
A significant increase has been observed in the use of Underwater Wireless Sensor Networks (UWSNs) over the last few decades. However, there exist several associated challenges with UWSNs, mainly due to the nodes' mobility, increased propagation delay, limited bandwidth, packet duplication, void holes, and Doppler/multi-path effects. To address these challenges, we propose a protocol named "An Efficient Routing Protocol based on Master-Slave Architecture for Underwater Wireless Sensor Network (ERPMSA-UWSN)" that significantly contributes to optimizing energy consumption and data packet's long-term survival. We adopt an innovative approach based on the master-slave architecture, which results in limiting the forwarders of the data packet by restricting the transmission through master nodes only. In this protocol, we suppress nodes from data packet reception except the master nodes. We perform extensive simulation and demonstrate that our proposed protocol is delay-tolerant and energy-efficient. We achieve an improvement of 13% on energy tax and 4.8% on Packet Delivery Ratio (PDR), over the state-of-the-art protocol.
... This method reduces the energy consumption of a single transmission, but the nodes closer to the ''vector'' work more frequently than the other nodes, which makes it easier to exhaust or damage, resulting in the lifetime of the entire system shorter. Hereafter, researchers have proposed several routing protocols to improve VBF, such as hop-by-hop VBF (HH-VBF) [7] and adaptive hop-by-hop VBF (AHH-VBF) [8] which make the forwarding node less 57166 VOLUME 9, 2021 prone to energy exhaustion in VBF protocol. H. Yan et al. in [9] proposed a depth based routing (DBR), which transmits data from the underlying node to the surface node based on depth information. ...
For a given source-destination pair in multi-hop underwater acoustic sensor networks (UASNs), an optimal route is the one with the lowest energy consumptions that usually consists of the same relay nodes even under different transmission tasks. However, this will lead to the unbalanced payload of the relay nodes in the multi-hop UASNs and accelerate the loss of the working ability for the entire system. In this paper, we propose a node payload balanced ant colony optimal cooperative routing (PB-ACR) protocol for multi-hop UASNs, through combining the ant colony algorithm and cooperative transmission. The proposed PB-ACR protocol is a relay node energy consumption balanced scheme, which considers both data priority and residual energy of each relay node, aiming to reduce the occurrence of energy holes and thereby prolong the lifetime of the entire UASNs. We compare the proposed PB-ACR protocol with the existing ant colony algorithm routing (ACAR) protocol to verify its performances in multi-hop UASNs, in terms of network throughput, energy consumption, and algorithm complexity. The simulation results show that the proposed PB-ACR protocol can effectively balance the energy consumption of underwater sensor nodes and hence prolong the network lifetime.
... Moving further, underwater resources are paid attention by scientists due to the depletion of terrestrial resources. UWSNs have many uses, such as being commonly used in coastal surveillance and assurance, an expectation of sea calamity, observation of underwater contamination, military protection, road assistance, management of the aquatic oceanic climate, investigation of underwater properties, monitoring of water quality, and so on in [1][2][3]. ...
Energy-efficient management and highly reliable communication and transmission mechanisms are major issues in Underwater Wireless Sensor Networks (UWSN) due to the limited battery power of UWSN nodes within an harsh underwater environment. In this paper, we integrate the three main techniques that have been used for managing Transmission Power-based Sparsity-conscious Energy-Efficient Clustering (CTP-SEEC) in UWSNs. These incorporate the adaptive power control mechanism that converts to a suitable Transmission Power Level (TPL), and deploys collaboration mobile sinks or Autonomous Underwater Vehicles (AUVs) to gather information locally to achieve energy and data management efficiency (Security) in the WSN. The proposed protocol is rigorously evaluated through extensive simulations and is validated by comparing it with state-of-the-art UWSN protocols. The simulation results are based on the static environmental condition, which shows that the proposed protocol performs well in terms of network lifetime, packet delivery, and throughput.
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.
Insights and recommendations for the next steps are provided in this paper to better harness technology innovation for sustainable development. Over the past several years, the global industrial environment has seen a significant transformation as a result of numerous technical discoveries, inventions, and improvements. With the development of the Internet of Things (IoT) in recent years, underwater wireless sensor networks (UWSN) have. In the current study, a thorough evaluation of the potential use of cutting-edge IoT technology over WSN is done. The term "Internet of Things" (IoT) describes how different physical items and gadgets are connected online. Last but not least, the study's findings about the difficulties in enabling technology and the best course of action for future improvement in attaining sustainability and an effective UWSN.
Reinforcement learning (RL) has been successfully applied to underwater routing protocols due to its powerful ability of distributed decision making. However, the traditional RL has slow convergence speed and low learning efficiency in underwater. Meanwhile, too many studies focus on using RL to find low hop paths rather than short distance paths in underwater routing, while the long distance of ocean communication is the significant reason for the packets collision and energy loss in underwater. Based on the above problems, this paper proposes the PDDQN-HHVBF (Empirical Priority DDQN to Improve Hop-by-Hop Vector-Based Forwarding) protocol for M-UWSNs (Mobile source node Underwater Wireless Sensor Networks), in which AUV (Autonomous Underwater Vehicle) is used as source node to collect data and transmit data hop-by-hop to Sink node through underwater nodes. The proposed protocol is adopt to find the optimal relay nodes in pipeline referred HHVBF protocol by requesting the max Q value according to three states of the residual energy of nodes, the number of candidate relay nodes and the geographical location information of all candidate relay nodes in time. This because PDDQN-HHVBF avoids the strong correlation between data samples, and its playback samples will not be too concentrated or lead to over fitting. It can converge rapidly in underwater environment. In addition, the requesting Q value mechanism related to the geographical location information can find the optimal relay node with short distance propagation in large-scale networks, which will reduce the number of packets collision, and then saving energy and improving network lifetime. In addtion, the in-time requesting for Q value can cope with the nodes drift affected by ocean current movement. In addition, the Q value related to the residual energy of nodes and the number of candidate relay nodes will effectively load balancing nodes, prolong network lifetime and avoid routing holes. Finally, the “Store-Carry-Forward” mechanism proposed for AUV, this mechanism store and carry packets when facing routing holes until find the optimal relay node for forwarding, which will improve PDR and save energy of AUV significantly. The simulation results show that, the proposed PDDQN-HHVBF protocol converges about 30% faster than DQELR. Although its delay is higher than DQELR and ROEVA for requesting Q value. It outperforms VBF, HHVBF, DQELR, and ROEVA in terms of energy efficency, PDR, and lifetime, which are analyzed by varying speed of nodes from 0 m/s to 3 m/s with 1000 nodes and varying number of nodes from 500 to 3000 with speed in 1 m/s.
Underwater data collection is an importance part in the process of network monitoring, network management and intrusion detection. However, the limited-energy of nodes is a major challenge to collect underwater data. The solution of this problem are not only in the hands of network topology but in the hands of path of autonomous underwater vehicle (AUV). With the problem in hand, an energy-efficient data collection scheme is designed for mobile underwater network. Especially, the data collection scheme is divided into two phases, i.e., routing algorithm design for sensor nodes and path planing for AUV. With consideration of limited-energy and network robustness, Q-learning based dynamic routing algorithm is designed in the first phase to optimize the routing selection of nodes, through which a potential-game based optimal rigid graph method is proposed to balance the trade-off between the energy consumption and the network robustness. With the collected data, Q-learning based path planning strategy is proposed for AUV in the second phase to find the desired path to gather the data from data collector, then a mode-free tracking controller is developed to track the desired path accurately. Finally, the performance analysis and simulation results reveal that the proposed approach can guarantee energy-efficient and improve network stability.
The Underwater Wireless Acoustic Sensors are facing several challenges due to their limited energy power that can significantly affect their network performances, hence the design of an efficient and reliable routing protocol for the underwater sensor communication is becoming the main purpose for the researchers, however, in this article, a new mechanism is proposed to balance the underwater network energy consumption due to the frequent data packet forwarding, whereas the protocol uses a method that is based on the historical nodes energy, where sensor that are excessively consuming energy are considered as overloaded node and has to be excluded from the forwarding process depending on their priority value. The implementation and simulation have been performed using NS-2 network simulator, based on the well-known protocol for the underwater acoustic communication ‘Vector-Based Forwarding routing protocol’, the results shows the performance of the proposed mechanism over the VBF in term of energy consumption and efficiency, successful delivery data, and end to end delay.
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This article has been withdrawn as part of the withdrawal of the Proceedings of the International Conference on Emerging Trends in Materials Science, Technology and Engineering (ICMSTE2K21). Subsequent to acceptance of these Proceedings papers by the responsible Guest Editors, Dr S. Sakthivel, Dr S. Karthikeyan and Dr I. A. Palani, several serious concerns arose regarding the integrity and veracity of the conference organisation and peer-review process. After a thorough investigation, the peer-review process was confirmed to fall beneath the high standards expected by Materials Today: Proceedings.
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Article in Persian, access through: http://navy.iranjournals.ir/article_243785.html?lang=en
Underwater Wireless Sensor Networks (UWSNs) is an emerging technology for the monitoring of aquatic assets and frequently applied in several domains like underwater information gathering, ocean sampling network, anonymous vehicles, disaster prevention and submarine detection. Recently, UWSNs have been getting significant attention of researchers from both academia and industry. As a result, several studies have been carried out to perform certain improvements in UWSNs techniques, tools, protocols and architectures. In this regard, there is a dire need to investigate and summarize the modern UWSNs trends altogether within a single study. To achieve this, a Systematic Literature Review (SLR) is performed in this article to comprehensively analyze the latest developments in UWSNs. Particularly, 34 research studies published during 2012-2020 have been selected and examined in the area of UWSNs. This leads to the identification of 21 modern routing protocols and 11 tools. Furthermore, 5 different architecture types and 3 communication media technologies are presented in the context of UWSNs. Finally, a comparative analysis of routing protocols is done on the basis of important evaluation metrics. It has been concluded that there exist adequate approaches, protocols and tools for the monitoring of UWSNs. However, the design verification capabilities of existing approaches are insufficient to meet the growing demands of UWSNs. The findings of this article provide solid platform to enhance the current UWSNs tools and techniques for large and complex networks.
Due to the problems of high bit error rate and delay, low bandwidth and limited energy of sensor nodes in underwater acoustic sensor network (UASN), it is particularly important to design a routing protocol with high reliability, strong robustness, low end-to-end delay and high energy efficiency which can flexibly be employed in dynamic network environment. Therefore, a reinforcement learning-based opportunistic routing protocol (RLOR) is proposed in this paper by combining the advantages of opportunistic routing and reinforcement learning algorithm. The RLOR is a kind of distributed routing approach, which comprehensively considers nodes peripheral status to select the appropriate relay nodes. Additionally, a recovery mechanism is employed in RLOR to enable the packets to bypass the void area efficiently and continue to forward, which improves the delivery rate of data in some sparse networks. The simulation results show that, compared with other representative underwater routing protocols, the proposed RLOR performs well in end-to-end delay, reliability, energy efficiency and other aspects in underwater dynamic network environments.
Due to the significant advances of wireless sensor networks (WSNs), researchers are eager to use this technology in the subsea applications. Because of rapid absorption of high radio frequency in the water, acoustic waves are used as communication medium, which pose new challenges, including high propagation delay, high path loss, low bandwidth, and high-energy consumption. Because of these challenges and high movement of nodes by water flow, end-to-end routing methods used in most of existing routing protocols in WSNs are not applicable to underwater environments. Therefore, new routing protocols have been developed for underwater acoustic sensor networks (UWASNs) in which most of the routing protocols take advantage of greedy routing. Due to inapplicability of global positioning system (GPS) in underwater environments, finding location information of nodes is too costly. Therefore, based on a need for location information, we divided the existing greedy routing protocols into two distinctive categories, namely, location-based and location-free protocols. In addition, location-free category is divided into two subcategories based on method of collecting essential information for greedy routing, including beacon-based and pressure-based protocols. Furthermore, a number of famous routing protocols belonging to each category are reviewed, and their advantages and disadvantages are discussed. Finally, these protocols are compared with each other based on their features.
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.
In this paper, we propose a reliable and energy-efficient routing algorithm for underwater wireless sensor networks (UWSNs). We first use a sphere energy depletion model to analyze the energy consumption of nodes in UWSNs. We then extend the model by considering the node mobility in UWSNs. Our analysis is in accordance with the common view that although water flows might cause the underwater environment more dynamic, this instability can actually improve energy-efficiency. However, the nodes closer to the sink still tend to die early, causing network partition around the sink. Accordingly, we propose a Reliable and Energy BAlanced Routing algorithm (REBAR). We explore the tradeoff between packet delivery ratio and energy efficiency. We design an adaptive scheme for setting data propagation range in order to balance the energy consumption throughout the network. Multi-path routing is used to provide redundancy. We further extend REBAR to deal with possible routing voids in the network which could be common in UWSNs. Simulation results show that our protocol outperforms existing VBF-based approaches in terms of reliability and network lifetime.
Wireless sensor networks, whether terrestrial or underwater, usually contain hundreds or in some cases thousands of micro-sensor nodes, that are randomly and densely deployed. In this paper we propose a clustering algorithm based on the geographical location of the sensor nodes for a 3-D hierarchical network architecture called LCAD. An energy model has been proposed and used to analyze the performance of the algorithm.
Energy optimized Path Unaware Layered Routing Protocol (E-PULRP) for dense 3D Underwater Sensor Network (UWSN) is proposed and analysed in this paper. In the proposed E-PULRP, sensor nodes report events to a stationary sink node using on the fly routing. E-PULRP consists of a layering phase and communication phase. In the layering phase, a layering structure is presented wherein nodes occupy different layers in the form of concentric shells, around a sink node. The layer widths and transmission energy of nodes in each layer are chosen taking into consideration the probability of successful packet transmission and minimization of overall energy expenditure in packet transmission. During the communication phase, we propose a method to select intermediate relay nodes on the fly, for delivering packets from the source node to sink node. We develop a mathematical framework to analyse the energy optimization achieved by E-PULRP. We further obtain expressions for throughput, delay and derive performance bounds for node densities and packet forwarding probabilities, for given traffic conditions. A comparison is made between the results obtained based on simulations and analytical expressions. The energy efficiency is also demonstrated in comparison with existing routing protocol for underwater sensor networks.
Underwater sensor nodes will find applications in oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. Moreover, unmanned or autonomous underwater vehicles (UUVs, AUVs), equipped with sensors, will enable the exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic networking 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 characteristics of the underwater channel are detailed. The main challenges for the development of efficient networking solutions posed by the underwater environment are detailed and a cross-layer approach to the integration of all communication functionalities is suggested. Furthermore, open research issues are discussed and possible solution approaches are outlined.
With the advancements of acoustic modem technology that supports better data rates with reliable communications, current research focuses on algorithms those can support such technology in a better way. During the last two decades, many protocols suggested in order to handle the adverse environment of underwater communications. This continued research results in improved performance as compare to initial communication systems. But still underwater issues like limited bandwidth, high propagation delays and 3-D topology as well as power constraints of the sensor nodes are challenges for the successful routings. A series of survey papers provide an excellent comparison of such algorithms and different networking challenges during the current decade, but still a lot left to investigate. In this paper we will explore the developments of some of the important routing algorithms, and a survey with different comparisons, those have been proposed for the partially connected underwater environments. In addition, at the end we will give some future directions, which can be helpful in order to construct the algorithms for such environments.
Underwater Wireless Sensor Networks (UWSNs) provide a solution for monitoring those unstable environments which is considered frightening for human presence. These networks are mostly formed by acoustic sensor nodes and surface sinks called buoys that are connected to any onshore control centre. The reliable delivery of sensed data to the surface sink is a challenging task as compared to forwarding the collected data to the control centre. Acoustic channel characteristics create many problems like, low available bandwidth, large propagation delays and high error probability that restrict the efficiency of UWSNs. Beside these, availability of limited resources and continuous node movements are major threats for the reliable data deliveries. With these constraints, it is a difficult task to design a protocol which has the ability to maximize the reliability of these networks. In this paper we provide a reliability model in order to insure the reliable data deliveries to the surface sinks. For this, we proposed two hop acknowledgment (2H-ACK) reliability model, where two copies of the same data packet are maintained in the network without extra burden on the available resources. Simulation results show that 2H-ACK can achieve better delivery ratios as compare to traditional hop-by-hop acknowledgment reliability without additional resource consumption.
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
The goal of this paper is to gain deep understanding of how location-dependent propagation latency affects medium access control (MAC) by using ALOHA as a case study. MAC protocols in underwater acoustic networks suffer from latency that is five orders-of-magnitude larger than that in radio networks. Existing work on analyzing MAC through- put in RF networks, where the propagation latency is negli- gible, generally makes assumptions that render propagation latency irrelevant. As a result, only transmit time is consid- ered as being uncertain in contention-based protocols. We introduce the spatial dimension of uncertainty that is inher- ent to varying locations of transmitters, resulting in unequal propagation latency to a receiver, where collision occurs. We show through simulation that the benefit of synchronization in slotted ALOHA is lost due to such latency. We propose a modification that adds guard bands to transmission slots to handle spatial uncertainty. We then perform simulation and first order analysis on this modified MAC to find its optimal operating parameters.
In this paper, architectures for two-dimensional and three -dimensional underwater sensor networks are discussed. A detailed overview on the current solutions for medium access control, network, and transport layer protocols are given and open research issues are dis- cussed.
We propose a localization scheme for underwater acoustic sensor networks (UWSN) that does not require a priori infra-structure or synchronization between nodes. An autonomous underwater vehicle (AUV) aids in localizing the sensor nodes while roaming across the underwater sensor field. The objectives of this paper are to describe how to localize nodes using AUV and to describe the tradeoffs involved, i.e. ratio of localized nodes and localization accuracy. We show that localization success improves as the duration of the AUV localization process increases. In addition, we investigated localization using two methods, bounding-box and triangulation. The former achieves a higher localization ratio but with a higher error. In certain scenarios, we achieved 100% nodes localized with 3% error.
Wireless sensor networks consist of small nodes with sensing, computation, and wireless communications capabilities. Many routing, power management, and data dissemination protocols have been specifically designed for WSNs where energy awareness is an essential design issue. Routing protocols in WSNs might differ depending on the application and network architecture. In this article we present a survey of state-of-the-art routing techniques in WSNs. We first outline the design challenges for routing protocols in WSNs followed by a comprehensive survey of routing techniques. Overall, the routing techniques are classified into three categories based on the underlying network structure: flit, hierarchical, and location-based routing. Furthermore, these protocols can be classified into multipath-based, query-based, negotiation-based, QoS-based, and coherent-based depending on the protocol operation. We study the design trade-offs between energy and communication overhead savings in every routing paradigm. We also highlight the advantages and performance issues of each routing technique. The article concludes with possible future research areas.
Instrumenting the physical world through large networks of
wireless sensor nodes, particularly for applications like environmental
monitoring of water and soil, requires that these nodes be very small,
lightweight, untethered, and unobtrusive. The problem of localization,
that is, determining where a given node is physically located in a
network, is a challenging one, and yet extremely crucial for many of
these applications. Practical considerations such as the small size,
form factor, cost and power constraints of nodes preclude the reliance
on GPS of all nodes in these networks. We review localization techniques
and evaluate the effectiveness of a very simple connectivity metric
method for localization in outdoor environments that makes use of the
inherent RF communications capabilities of these devices. A fixed number
of reference points in the network with overlapping regions of coverage
transmit periodic beacon signals. Nodes use a simple connectivity
metric, which is more robust to environmental vagaries, to infer
proximity to a given subset of these reference points. Nodes localize
themselves to the centroid of their proximate reference points. The
accuracy of localization is then dependent on the separation distance
between two-adjacent reference points and the transmission range of
these reference points. Initial experimental results show that the
accuracy for 90 percent of our data points is within one-third of the
separation distance. However, future work is needed to extend the
technique to more cluttered environments
An ad-hoc network is the cooperative engagement of a collection of Mobile Hosts without the required intervention of any centralized Access Point. In this paper we present an innovative design for the operation of such ad-hoc networks. The basic idea of the design is to operate each Mobile Host as a specialized router, which periodically advertises its view of the interconnection topology with other Mobile Hosts within the network. This amounts to a new sort of routing protocol. We have investigated modifications to the basic BellmanFord routing mechanisms, as specified by the Routing Information Protocol, making it suitable for a dynamic and self-starting network mechanism as is required by users wishing to utilize ad-hoc networks. Our modifications address some of the previous objections to the use of Bellman-Ford, related to the poor looping properties of such algorithms in the face of broken links and the resulting time dependent nature of the interconnection topology describing th...
Providing better communication in UWSNs and maximize the communication performance is challenging issue due to volatile characteristics of underwater environment. Radio signal cannot properly propagate in underwater, so there is need, such type of acoustic modem technology that can supports better data rates and reliable underwater wireless communications. Further, nodes mobility, 3-D spaces brings some critical challenges for the researcher to design new routing protocol for UWSNs, to handle the issues like high end to end delays, Propagation delay, as well as power constraints of the sensor nodes. Many routing algorithms have been proposed in last two decades and some of them provide better solution to handle such type of issues. In this paper, we proposed a novel routing protocol called Layer by layer Angle Based Flooding (L2-ABF.), to address the problem node swaying issue, end-to-end delays, and node energy consumption. In L2-ABF, every node can calculate its flooding angle to forward data packet to the next upper layer toward the surface sinks without using any explicit configuration and location information. The simulation results show that L2-ABF has some advantages over some existing flooding base techniques and can easily manage quick routing changes where node movements are frequent.
Based on LEACH algorithm, we propose an improved HMR-LEACH algorithm (Hierarchical Multi-path Routing-LEACH), which improves election of cluster head and adopts multi-hop algorithm instead of one hop to transmission data. When chooses transmission path, HMR-LEACH algorithm takes energy and distance into account and assigns a probability to each transmitting path by weight. Simulation result indicates that HMR-LEACH outperforms the LEACH algorithm and prolongs the life of the network dramatically.
Compared to land-based sensor networks, Underwater Acoustic Sensor Networks have several new challenges, such as dynamic topology, limited network lifetime. To achieve long network lifetime, existing researches use clustering method to assure energy-efficiency. However, nodes far away from sink are easily to exhaust energy due to directly communication with sink. Besides, in HEED protocol, the nodes must be location-aware in order to communicate with the sink node. However, GPS radio receivers cannot function properly in underwater situation. Moreover, in industry, homogenous nodes with identical hardware are more welcomed concerning manufacture efforts and costs. In this paper, we provide a new homogeneous, dynamic topology adaptive, multi-hop routing protocol LUM-HEED (Location Unaware Multi-hop based on HEED) which suits for the real underwater situation and is more convenient and economic in industry application. Simulation results show that this protocol can prolong network lifetime and balance network traffic.
A simple yet accurate nine‐term, eight‐variable equation for sound speed in the oceans, suitable for programmable pocket calculators, is presented. Ranges of validity encompass: temperature −2° to 30° C, salinity 30° to 40°/°°, and depth 0 to 8000 m. Good quality oceanographic data at 15 worldwide stations, including two in the Mediterranean, were utilized for the computations. The Del Grosso and Mader [J. Acoust. Soc. Am. 52, 961–974 (1972)] sound‐speedequation was employed as ’’truth’’ after comparisons among Wilson [J. Acoust. Soc. Am. 32, 641–644. 1357 (1960)] and others. A precise method of computing pressure is detailed. Practical differences in critical depth, excess depth, conjugate depth, deep sound‐speed gradients, and echo‐sounder corrections are shown to be small between computations based on Wilson or Del Grosso and Mader sound‐speedequations.
Providing an efficient communication for the underwater wireless sensor networks is a significant problem due to the unique characteristics of such environments. Radio signal cannot propagate well in deep water, and we have to replace this with the acoustic channel. This replacement results in many issues like high latency due to less propagation speeds, low bandwidths and high error probability. In addition, new features like node mobility with water currents and 3-dimensional space brings additional challenges to the underwater sensor network (UWSN) protocol design. Many routing protocols have been proposed for such environments but most of them considered that the complete dimensional location of all the sensor nodes is already known through a localization process, which itself is a challenging task in UWSNs. In this paper, we propose a novel routing protocol, called Hop-by-Hop Dynamic Addressing Based (H2-DAB), in order to provide scalable and time efficient routing. Our routing protocol will take advantage of the multiple-sink architecture of the underwater wireless sensor networks. The novelty of H2-DAB is that, it does not require any dimensional location information, or any extra specialized hardware compared to many other routing protocols in the same area. Our results show that H2-DAB effectively achieves the goals of higher data deliveries with optimal delays and energy consumptions.
The design of routing protocols for Underwater Wireless Sensor Networks (UWSNs) poses many challenges due to the intrinsic
properties of underwater environments. In this paper we present DUCS (Distributed Underwater Clustering Scheme), a new GPS-free
routing protocol that does not use flooding techniques, minimizes the proactive routing message exchange and uses data aggregation
to eliminate redundant information. Besides, DUCS assumes random node mobility and compensates the high propagation delays
of the underwater medium using a continually adjusted timing advance combined with guard time values to minimize data loss.
The theoretical and simulation studies carried out demonstrate its effectiveness.
KeywordsAcoustic communications–Routing–Energy efficiency–Underwater networking
Unlike terrestrial sensor networks, underwater sensor networks (UWSNs) have different characteristics such as a long propagation delay, a narrow bandwidth and high packet loss. Hence, existing path setup-based routing protocols proposed for terrestrial sensor networks are not applicable in the underwater environment. For example, they take much time when establishing a path between source and destination nodes due to the long propagation delay. In addition, the path establishment requires much overhead of control messages. Moreover, the dynamic and high packet loss degrades reliability, which invokes more retransmissions. Even though exiting routing protocols such as VBF were proposed to improve the reliability, they did not take into account the link quality. That is, there is no guarantee that packets reach the sink safely especially when a link is error-prone. In this paper, we therefore propose a directional flooding-based routing protocol, called DFR. Basically, DFR relies on a packet flooding technique to increase the reliability. However, the number of nodes which flood a packet is controlled in order to prevent a packet from flooding over the whole network and the nodes to forward the packet are decided according to the link quality. In addition, DFR also addresses a well-known void problem by allowing at least one node to participate in forwarding a packet. Our simulation study using ns-2 proves that DFR is more suitable for UWSNs especially when links are prone to packet loss.
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.
Path loss of an underwater acoustic communication channel de- pends not only on the transmission distance, but also on the sig- nal frequency. As a result, the useful bandwidth depends on the transmission distance, a feature that distinguishes an underwater acoustic system from a terrestrial radio one. This fact influences the design of an acoustic network: a greater information through- put is available if messages are relayed over multiple short hops instead of being transmitted directly over one long hop. We assesthe bandwidthdependencyon the distanceusing an an- alytical method that takes into account physical models of acoustic propagation loss and ambient noise. A simple, single-path time- invariant model is considered as a first step. To assess the fun- damental bandwidth limitation, we take an information-theoretic approach and define the bandwidth corresponding to optimal sig- nal energy allocation - one that maximizes the channel capacity subject to the constraint that the transmission power is finite. Nu- merical evaluation quantifies the bandwidth and the channel ca- pacity, as well as the transmission power needed to achieve a pre- specified SNR threshold, as functions of distance. These results lead to closed-form approximations, which may become useful tools in the design and analysis of acoustic networks.
Multi-hop transmission is considered for large coverage ar- eas in bandwidth-limited underwater acoustic networks. In this paper, we present a scalable routing technique based on location information, and optimized for minimum energy per bit consumption. The proposed Focused Beam Rout- ing (FBR) protocol is suitable for networks containing both static and mobile nodes, which are not necessarily synchro- nized to a global clock. A source node must be aware of its own location and the location of its final destination, but not those of other nodes. The FBR protocol can be defined as a cross-layer ap- proach, in which the routing protocol, the medium access control and the physical layer functionalities are tightly cou- pled by power control. It can be described as a distributed algorithm, in which a route is dynamically established as the data packet traverses the network towards its final destina- tion. The selection of the next relay is made at each step of the path after suitable candidates have proposed themselves. The system performance is measured in terms of energy per bit consumption and average packet end-to-end delay. The results are compared to those obtained using pre-establi- shed routes, defined via Dijkstra's algorithm for minimal power consumption. It is shown that the protocol's perfor- mance is close to the ideal case, as the additional burden of dynamic route discovery is minimal.
Due to the long propagation delay and high error rate of acoustic channels, it is very challenging to provide reliable data transfer for time-critical applications in an energy-efficient way. On the one hand, traditional retransmission upon failure usually introduces very large end-to-end delay and is thus not proper for time-critical services. On the other hand, common approaches without retransmission consume lots of energy. In this paper, we propose a new multipath power-control transmission (MPT) scheme, which can guarantee certain end-to-end packet error rate while achieving a good balance between the overall energy efficiency and the end-to-end packet delay. MPT smartly combines power control with multipath routing and packet combining at the destination. With carefully designed power-control strategies, MPT consumes much less energy than the conventional one-path transmission scheme without retransmission. Besides, since no hop-by-hop retransmission is allowed, MPT introduces much shorter delays than the traditional one-path scheme with retransmission. We conduct extensive simulations to evaluate the performance of MPT. Our results show that MPT is highly energy-efficient with low end-to-end packet delays.
Progress in underwater acoustic telemetry since 1982 is reviewed
within a framework of six current research areas: (1) underwater channel
physics, channel simulations, and measurements; (2) receiver structures;
(3) diversity exploitation; (4) error control coding; (5) networked
systems; and (6) alternative modulation strategies. Advances in each of
these areas as well as perspectives on the future challenges facing them
are presented. A primary thesis of this paper is that increased
integration of high-fidelity channel models into ongoing underwater
telemetry research is needed if the performance envelope (defined in
terms of range, rate, and channel complexity) of underwater modems is to
expand