Two-hop Neighborhood Information Research Articles

QQAR: A Q-learning-based QoS-aware routing for IoMT-enabled wireless body area networks for smart healthcare

Recently, the Internet of Medical Things (IoMT) has gained broad acclaim in the academic and industrial sectors due to its use in integrating medical devices and healthcare systems. Wireless body area networks (WBANs) are a promising technology in smart healthcare for real-time patient monitoring and health data analysis by medical professionals. Efficient data transmission is essential in ensuring reliable and timely delivery of healthcare facilities. Healthcare services require reliable, delay-sensitive, energy- and congestion-aware communication, which makes it challenging to design a routing protocol. To address quality of services (QoS) in IoMT-enabled WBANs for healthcare, we propose Q-learning-based quality of services (QoS) aware routing (QQAR). Firstly, we used two-hop-based link reliability estimation to ensure link reliability from sources to sink nodes. Routing decisions using two-hop neighbor information guarantees successful packet delivery. Secondly, we differentiated the packets based on traffic priority, which assures the delivery of critical packets even in a congested network. Particularly, considering two-hop node velocity with energy balancing enhanced the guarantee of timely packet delivery before deadlines. In addition, the multi-sink approach enhanced network reliability. Finally, we utilized Q-learning to select suitable neighbor nodes for packet forwarding in a decentralized fashion. A multi-sink load balance and congestion control mechanism adjusts the routing decisions in the QQAR to avoid congestion. Our simulation and comparison results showed that QQAR outperforms the existing routing protocols across various performance metrics under distinct network conditions.

Q-learning-based routing inspired by adaptive flocking control for collaborative unmanned aerial vehicle swarms

A collaborative unmanned aerial vehicle (UAV) swarm can support various applications, including aerial surveillance and emergency communication. Owing to the high mobility, limited energy of UAVs, and frequent link breakages, data routing from remote UAVs to a base station may produce retransmissions, loops, energy holes, and long delay. In a UAV swarm network, therefore, relative mobility, path stability, and delay should be jointly taken into consideration to improve routing performance because they are highly coupled with each other. However, they are not properly exploited in the existing literature. To address these issues, in this paper, a Q-learning (QL)-based routing protocol inspired by adaptive flocking control (QRIFC) is proposed. The proposed adaptive flocking control algorithm generates optimal mobility with fairness in travel distance for each UAV to control the optimal node density. It also addresses the trade-off between aerial coverage and quality of service in connectivity by imposing constraints on the minimum separation distance and maximum allowable inter-UAV spacing using two-hop neighbor information. Additionally, it provides a stable link duration (LD) between neighboring UAVs and optimizes the control overhead. Furthermore, QL performs multi-objective optimization by utilizing a new state exploration and exploitation strategy to select an optimal routing path in terms of delay, stable path selection defined by predictive LD, and energy consumption. According to an extensive performance study, the proposed QRIFC outperforms existing routing protocols by 21-40 percent of average end-to-end delay and 9-23 percent of average packet delivery ratio, with less retransmissions.

Adaptively prioritizing candidate forwarding set in opportunistic routing in VANETs

Opportunistic routing (OR) paradigms in vehicular networks via opportunistic candidate set selection have a better performance over the pre-defined next-hop node in terms of packet delivery rate. Nevertheless, uneven vehicle distribution, highly dynamic topology, varying link interference, and bandwidth restrictions impose drastic challenges for satisfying applications requirements in static prioritizing candidate set selection policies. Besides, fulfilling quality of service (QoS) requirements of heterogeneous applications, due to the limited local topology perspective and many involving conflicting routing criteria, will be further compromised. Considering the candidate set selection policy as a Multi-Criteria Decision Making (MCDM) task, an adaptive two-hop cooperative forwarding set selection strategy called APFS is proposed in this paper. By developing a local topology perspective to the two-hop neighbor information, the APFS scheme jointly considers indicators of link stability, delay assessment, and link good-put as routing criteria. Analytical Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methods are employed in two different scenarios in prioritizing candidate forwarding sets. First, classical AHP-TOPSIS technique with a mutable pair-wise comparison matrix is applied, and then Neutrosophic Set (NS) is combined with the classical AHP-TOPSIS method to handle ambiguous vehicular environments. The simulation results show that the APFS strategy using both prioritization policies have significantly improved the performance of packet delivery ratio, average end-to-end delay, throughput, and hop counts as compared to other schemes.

Link utility aware geographic routing for urban VANETs using two-hop neighbor information

Routing in Vehicular Ad Hoc Networks (VANETs) is a challenging problem. While geographic routing protocols are preferred for VANETs due to their scalability, they are focused on finding next-hop nodes closer to the destination without considering their current load or network traffic. In addition, routing decisions based on only one-hop neighbors information might be less optimal since they do not consider the availability of further suitable nodes for forwarding. Thus, such selected next-hop nodes may become overloaded with too much traffic that exceeds their available bandwidth, and may even result in significant packet losses if no other node suitable for forwarding can be found. In this paper, we propose a novel geographic routing protocol named Geo-LU. The proposed protocol improves the routing performance by extending the local view of the network topology at the current forwarder to include two-hop neighbor information. Moreover, it utilizes our proposed link utility (LU) measure. LU considers the utility of a two-hop neighbor link by considering the minimum residual bandwidth on that link and its packet loss rate. By incorporating two-hop neighbor information and our proposed LU measure, the proposed protocol, Geo-LU, can react appropriately to the increased network traffic and to the frequent topology dis-connectivity in VANETs as confirmed by our simulation results.

Energy Efficient Mobility Aware Clustering Hybrid MAC Protocol in WSN

Mobility in Wireless Sensor Networks (WSN) poses many challenges to design Medium Access Control (MAC) protocol. In this paper, Energy efficient clustering Mobility Hybrid MAC (EMH-MAC) protocol is introduces to manage throughput, delay and energy consumption in WSN. EMH-MAC protocol merges the features of synchronous and asynchronous MAC protocols. EMH-MAC works in two stages: Clustering and Data transmission stage. In the clustering stage MMCDD protocol is used for election of Cluster Head (CH). Data transmission stage works in four segments: two-hop neighbor information, intra-semi synchronous, inter-synchronous communication and data transfer. EMH-MAC is evaluated using Network Simulator-3 and performance is compared with BN-MAC. Simulation results show that EMH-MAC performs well in comparison with BN-MAC in terms of throughput, delay and energy consumption by varying number of nodes and speed of nodes.

Using One-hop and Two-hop Neighbouring Information to Defend Against Sybil Attacks in Stationary Wireless Sensor Network

Considering the application of wireless sensor networks (WSNs) in critical areas like war fields, establishing security in these networks is of great challenge. One of the important and dangerous attacks in these networks is the Sybil attack. In this attack, a malicious node broadcasts several IDs simultaneously. Thus, the malicious node of the adversary attracts high traffic to itself and disrupts routing protocols and affects other operations of the network like data aggregation, voting, and resource allocation, negatively. In this paper, an efficient algorithm based on one-hop and two-hop neighborhood information is proposed to detect Sybil nodes in the stationary WSNs. The proposed algorithm is executed locally with the collaboration of neighboring nodes. The main purpose of the proposed algorithm is to increase the accuracy of detecting Sybil nodes under various conditions including the condition in which a malicious node broadcasts a few numbers of Sybil IDs which is the shortcoming of most existing algorithms. The proposed algorithm is simulated in MATLAB and its efficiency is compared with two similar algorithms in terms of true and false detection rates. The proposed algorithm not only reduces communication overhead but also increases the accuracy of detecting Sybil nodes compared to two similar algorithms.

Enhanced Geographic Routing with Two-Hop Neighborhood Information in Sparse MANETs

The advance of wireless and mobile communications and networking technologies enables networked nodes to transmit and receive data in ad hoc manners without resorting to dedicated network infrastructures. When nodes arbitrarily move in a geographic area, they carry data and attempt to exchange data during encountering each other in one-hop or multi-hop transmission range. Such a basic data delivery model is practical in many emerging application environments, like disaster, military and rural fields, etc., which turns out to be the research of routing in sparse mobile ad hoc networks (MANET). In sparse MANETs with lower node population or node density relatively, the performance of data delivery is highly affected by communication voids that arise from unpredictable transmission failure while no neighbors exist in mutual transmission ranges. This paper proposes a new geographic routing scheme to deal with critical communication voids in sparse MANETs. The proposed scheme exploits the geographic location and two-hop neighborhood information, and then devises a forwarding node selection policy for determining appropriate relay candidates that move towards target nodes in a network. To this end, this geographic routing scheme is able to reduce transmission overhead and end-to-end delay against communication voids in infrastructure-less environments. In addition, this paper examines the proposed scheme using synthetic studies on a dedicated opportunistic networking simulator. Simulated results show that this scheme obtains considerable performance in terms of successful delivery ratio and transmission overhead under the random waypoint mobility models in synthetic contexts of sparse MANETs.

Two-Hop Neighborhood Information Joint Double Broadcast Radius for Effective Code Dissemination in WSNs

With the development of software-defined network (SDN) technology, sensor nodes can update soft codes to enable themselves to have new functions so as to make wireless sensor network (WSN) full of new vitality. However, how to spread the new code to every node in the network quickly and energy-efficient is a challengeable issue. In this paper, a Two-hop Neighborhood Information joint Double Broadcast Radius (TNI-DBR) scheme is proposed to disseminate the codes in duty cycle-based WSNs in a fast and energy-efficient style. The main innovations of this paper are as follows. The TNI-DBR scheme makes full use of the unbalanced energy consumption of the sensor network in the process of data collection and doubles the broadcast radius in the area with redundant energy so that more nodes can receive the new code in one broadcast and the broadcast range is further, which can reduce the delay of code dissemination effectively. Different from the conventional code dissemination schemes that select broadcasting nodes according to the information of the one-hop neighbors, in the TNI-DBR scheme, an $O(n)$ two-hop neighbor information exchange algorithm is proposed to obtain the duty cycle information of the two-hop neighbors. The TNI-DBR scheme selects the best broadcasting nodes based on information in the range of two-hop neighbors to enlarge the number of active nodes and reduce the time required for code dissemination. Sufficient theoretical analysis and experimental results show that the TNI-DBR scheme can significantly optimize the performance of code dissemination. Compared to previous schemes, the delay of code dissemination can be reduced by 43.09%~78.69%, the number of broadcasts can be reduced by 44.51%~86.18%, and the energy utilization ratio is improved by about 24.5%.

Path Diversity Improved Opportunistic Routing for Underwater Sensor Networks.

The packets carried along a pre-defined route in underwater sensor networks are very vulnerble. Node mobility or intermittent channel availability easily leads to unreachable routing. Opportunistic routing has been proven to be a promising paradigm to design routing protocols for underwater sensor networks. It takes advantage of the broadcast nature of the wireless medium to combat packet losses and selects potential paths on the fly. Finding an appropriate forwarding candidate set is a key issue in opportunistic routing. Many existing solutions ignore the impact of candidates location distribution on packet forwarding. In this paper, a path diversity improved candidate selection strategy is applied in opportunistic routing to improve packet forwarding efficiency. It not only maximizes the packet forwarding advancements but also takes the candidate’s location distribution into account. Based on this strategy, we propose two effective routing protocols: position improved candidates selection (PICS) and position random candidates selection (PRCS). PICS employs two-hop neighbor information to make routing decisions. PRCS only uses one-hop neighbor information. Simulation results show that both PICS and PRCS can significantly improve network performance when compared with the previous solutions, in terms of packet delivery ratio, average energy consumption and end-to-end delay.

Improved Compressed Network Coding Scheme for Energy-Efficient Data Communication in Wireless Sensor Networks

An improved energy-efficient compressed network coding method is proposed for the data communication in the wireless sensor networks (WSNs). In the method, the compressed sensing and network coding are jointly used to improve the energy efficiency, and the two-hop neighbor information is employed to choose the next hop to further reduce the number of the transmissions. Moreover, a new packet format is designed to facilitate the intermediate node selection. To theoretically verify the efficiency of the proposed method, the expressions for the number of the transmissions and receptions are derived. Simulation results show that, the proposed method has higher energy efficiency compared with the available schemes, and it only requires a few packets to reconstruct measurements with reasonable quality.

QoS guarantee towards reliability and timeliness in industrial wireless sensor networks

Wireless Sensor Networks is a promising technology for industrial monitoring and process control. In industry the sensory measures should be delivered to control room in predefined deadline time. The reliable delivery of sensory measure degrades as the focus shift from wired domain to wireless domain. This happens due to unreliability of sensor node and communication link. Therefore, the adverse industrial environment condition posed great stress towards designing of an efficient and effective routing protocol that can ensure the quality of service by reliable and timeliness delivery of real-time data. This paper presents a new geographical routing protocol that works on the basis of two-hop neighbor information. This improves end-to-end packet delivery by minimizing the path setup and recovery latency to ensure the reliability and timeliness. It selects the reliable relay node by mapping packet deadline time to link velocity in such a way that the smaller deadline time packets follow the shorter path over the high speed, reliable links and larger deadline time packets follow path over energy efficient nodes. This process enhances the network life and maintains the shorter path for time critical data routing. This real-time data routing suffers when a forwarding node fails to access the potential relay node. Here, the transmission energy regulation mechanism support to accessing the potential relay node for improving the reliability and timeliness data delivery. The simulation results validate the claim that the proposed routing protocol achieves significant improvement in end-to-end deadline packet delivery ratio with the higher energy efficiency.

RTEA: Real-Time and Energy Aware Routing for Industrial Wireless Sensor Networks

This paper proposes a real-time and energy aware routing protocol for industrial wireless sensor networks, called RTEA. Two-hop neighborhood information routing is adopted from THVR routing protocol, however our routing protocol has low control packet overhead and differentiates packets based on their deadlines. The packet deadline is updated in each hop without using globally synchronized clocks. In addition to velocity, the distance to the sink is considered for reducing the number of relaying hops. Also, the delay between two one-hop neighbors is estimated by a new mechanism which considers the time that packets spend in each node beside the link delay. Simulation results show that RTEA can improve the performance in terms of delivery ratio and energy consumption.

A Dynamic Backup Path Management Method for TDMA Based WiMAX Client WMNs

This paper proposes a backup path management method for time division multiple access (TDMA) based client wireless mesh networks (WMNs). In a TDMA based client WMN, as links/nodes fail or as nodes perform handover and as flows enter and leave the network, the paths between various nodes change as well as the bandwidth available along these paths. In these networks, to support the quality of service requirements of flows, backup paths with the required bandwidth need to be established dynamically. Some methods are proposed in the literature to establish backup paths which handle link/node failures and node handover in ad hoc networks, but none of these methods can provide backup paths with the required bandwidth dynamically. To address that issue, the present paper proposes a backup path management method which is adaptive to both topological changes and traffic changes in a network. Each node along the current path between a source and a destination finds backup paths with the required bandwidth in order to handle failure of the link to its downstream node and its own failure or handover. Nodes use two-hop neighborhood information and slots status information of two-hop neighbors to establish backup paths. We prove that the number of backup paths available when a node N searches for backup paths to handle its own failure are more than the number of backup paths available when some other node searches for the backup paths for the failure of node N. Performance of the proposed method is compared with the performance of a naive path management (NPM) method in which always the source establishes backup paths whenever a link/node fails or a node performs handover, and also with the performance of a backup path management method proposed in the literature. The proposed method significantly outperforms the NPM method and the method selected from the literature. For example, when the speed of the mobile nodes is 50 m/s, the packet delivery ratio with the proposed method is 63 % more than the NPM method and 35 % more than the method selected from the literature.

Location-aided route discovery mechanism based on two-hop neighbor information for ad hoc network

This paper proposes a method to reduce overhead packets and end-to-end delay and improve reachability over an ad hoc network that uses a location-aided routing protocol. Location-aided routing is u...

CStorage: Decentralized compressive data storage in wireless sensor networks

In this paper, we employ compressive sensing (CS) to design a distributed compressive data storage (CStorage) algorithm for wireless sensor networks (WSNs). First, we assume that no neighbor information or routing table is available at nodes and employ the well-known probabilistic broadcasting (PB) to disseminate sensors reading throughout the network to form compressed samples (measurements) of the network readings at each node. After the dissemination phase, a data collector may query any arbitrary set of M ≪ N nodes for their measurement and reconstruct all N readings using CS. We refer to the first implementation of CStorage by CStorage-P.Next, we assume that nodes collect two-hop neighbor information and design a novel parameterless and scalable data dissemination algorithm referred to by alternating branches (ABs), and design CStorage-B. We discuss the advantages of CStorage-P and CStorage-B and show that they considerably decrease the total number of required transmissions for data storage in WSNs compared to existing work.

Location-Aided Route Discovery Based on Two-Hop Neighbor Information in Ad Hoc Networks

Location-Aided Route Discovery Based on Two-Hop Neighbor Information in Ad Hoc Networks

A traffic flow-oriented routing protocol for VANETs

AbstractThis paper presents a novel position-based routing protocol for vehicular ad hoc networks (VANETs) to enhance traffic safety and traffic organization and facilitate driving through a smart transportation system. The protocol is referred to as the traffic flow-oriented routing (TFOR) protocol for VANETs. It considers a real-time urban scenario with multi-lane and bi-directional roads. It chooses junction optimally considering vehicular traffic flows to accomplish robust routing paths and thereby forwarding the data packets. The new junction selection mechanism and routing between the junctions is based on two-hop neighbor information, which increases packet-delivery ratio and decreases end-to-end delay. We designed, implemented, and compared TFOR against existing routing protocols of VANETs (greedy-perimeter stateless routing (GPSR), geographic source routing (GSR), and enhanced greedy traffic-aware routing (E-GyTAR)). Simulation outcomes in urban scenarios show that TFOR minimizes average end-to-end delay and routing overhead by on average 15.3% and 19.5%, respectively, compared to GPSR. It reduces routing overhead up to 17% compared to GSR. TFOR maximizes packet-delivery ratio on an average of 17.5%, 10.7%, and 7.2% compared to GPSR, GSR, and E-GyTAR, respectively.

Real-Time Traffic-Differentiated QoS Routing for Wireless Sensor Networks

Wireless sensor networks (WSNs) emerge as underlying infrastructures for new classes of large scale networked embedded systems. However, WSNs system designers must fulfill the Qualityof-Service (QoS) requirements imposed by the applications (and users). Very harsh and dynamic physical environments and extremely limited resources are major obstacles for satisfying QoS metrics such as reliability, timeliness, and system lifetime. The limited communication range of WSN nodes, link asymmetry, and the characteristics of the physical environment lead to a major source of QoS degradation in WSNs. This paper proposes a Real-Time Traffic-Differentiated Routing protocol for Wireless Sensor Networks (WSNs). It targets WSN applications having different types of data traffic with several priorities. The protocol achieves to increase packet reception ratio and reduce end-to-end delay while considering multi-queue priority policy, two-hop neighborhood information, link reliability and power efficiency. The protocol is modular and utilizes memory and computational effective methods for estimating the link metrics. Numerical results show that the proposed protocol is a feasible solution to addresses QoS service differentiation for traffic with different priorities.

Practical Solution for Broadcasting in VANETs Using Neighbor Information

SUMMARY Due to vehicle movement and lossy wireless channels, providing a reliable and efficient multi-hop broadcast service in vehicular ad hoc networks (VANETs) is a well-known challenging problem. In this paper, we propose BR-NB (broadcast with neighbor information), a fuzzy logic based multi-hop broadcast protocol for VANETs. BR-NB achieves a low overhead by using only a subset of neighbor nodes to relay data packets. For the relay node selection, BR-NB jointly considers multiple metrics of the inter-vehicle distance, vehicle mobility and link quality by employing fuzzy logic. Since the expected coverage and vehicle mobility are inferred from the two-hop neighbor information which can be acquired from the hello message exchange, BR-NB is independent of position information. BR-NB provides a practical and portable solution for broadcast services in VANETs. We use computer simulations and real-world experiments to evaluate the performance of BR-NB.

On Reducing Broadcast Transmission Cost and Redundancy in Ad Hoc Wireless Networks Using Directional Antennas

Using directional antennas to conserve bandwidth and energy consumption in ad hoc wireless networks has attracted much attention from the research community in recent years. However, very little research has focused on applying directional antennas to broadcasting. In this paper, we propose a virtual link reduction (VLR)-based broadcasting protocol for ad hoc wireless networks using directional antennas. Based on two-hop neighborhood information, VLR relies on no location nor angle-of-arrival (AOA) information. VLR is a localized or distributed protocol, and it achieves full delivery. VLR operates on top of any existing broadcast routing protocols. In VLR, no node rebroadcasts a given packet more than once. No physical link is actually reduced, but if a packet has already been forwarded to the end node of the current link, the packet is no longer forwarded, that is, this link is virtually reduced. To evaluate the performance of the proposed VLR-based protocol, we conduct extensive simulation, for simplicity, assuming that there is no packet collision, no channel contention, and no mobility. Simulation results show that VLR outperforms most existing omnidirectional and directional broadcasting schemes in the sense that its normalized transmission cost and redundancy are significantly reduced. Based on the results, we conclude that VLR is more bandwidth and energy efficient.