Forwarding Set Research Articles

Energy-Efficient Opportunistic Routing Algorithm for Post-Disaster Mine Internet of Things Networks.

The Mine Internet of Things (MIoT), as a key technology for reconstructing post-disaster communication networks, enables a user to monitor and control the safety of an affected roadway. However, due to the challenging underground mine environment, the MIoT suffers from severe signal attenuation, vulnerable nodes, and limited energy, which result in a low level of network reliability for the post-disaster MIoT. To improve transmission reliability and reduce energy consumption, a directional-area-forwarding-based energy-efficient opportunistic routing (DEOR) approach for the post-disaster MIoT is proposed. DEOR defines a forwarding zone (FZ) for each node to route packets toward the sink. The candidate forwarding set (CFS) is constructed by the nodes within the FZ that satisfy the energy constraint and the neighboring node degree constraint. The nodes in the CFS are prioritized based on a routing quality evaluation, which takes the local attributes of the nodes, such as the directional angle, transmission distance, and residual energy, into consideration. DEOR adopts a recovery mechanism to address the issue of void nodes. The simulation results verify that the proposed DEOR approach outperforms the ORR, OBRN and ECSOR methods in terms of energy consumption, average hop count, packet delivery rate, and network lifetime.

Regular routine aware routing in opportunistic mobile social networks

AbstractDue to intermittent connectivity, routing protocols in opportunistic mobile social networks (OMSN) forward messages through opportunistic contacts. Previous opportunistic routing protocols focus on the past contact history of nodes to make a forwarding decision. It was found that predicting temporally evolving contacts and communities according to different times of the day would improve the accuracy of the prediction. In this paper, a routing paradigm called RRoutine is proposed that allows message holders to exchange multiple copies of the message based on the predicted number of communities. This distribution continues until the remaining copies of the message become one. Each message holder applies either inter or intra‐community forwarding and selects a set of potential forwarders based on the prediction of future encounters in the community and an expected remaining duration between two nodes (ERIMD). The estimation of ERIMD takes into account the sequence of daily activities, the time scale of current activities, and the return time to regular meetings of the nodes. Also, unlike traditional routing, where a single forwarder is selected, a set of potential candidates is selected and prioritized according to their contact prediction, with the most likely candidate receiving the highest priority. Simulation results obtained from synthetic and real mobility data show that the proposed paper improves the performance of the system in terms of message delivery rate, throughput, and latency.

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.

Energy-Efficient Smart Routing Based on Link Correlation Mining for Wireless Edge Computing in IoT

Modern Internet-of-Things (IoT) applications are heavily data driven and often require reliable data streams to achieve high-quality data mining. The concept of edge computing is introduced to reduce data latency and communication bandwidth between the cloud server and IoT edge devices. However, inefficient routing that may cause transmission failure or unnecessary data (re)transmission is still a key obstacle to obtain good and reliable data mining results. In this article, network coding combined with opportunistic routing is used to improve energy efficiency in wireless IoT infrastructure, considering the existence of link correlation. Studies have shown that packet receptions on wireless links are correlated, which is completely contrary to the assumption of link independence used in existing routing mechanisms. This assumption causes estimation errors in the calculation of expected number of transmissions for forwarders, which further affects the selection of forwarder set, and ultimately affects the performance of the protocol. We propose an intrasession network coding mechanism based on the mining of link correlation. A novel smart routing method is proposed to accurately estimate the number of transmissions required by forwarders, together with an algorithm for selecting a forwarder set with more optimal number of transmissions. Simulation results demonstrate that the proposed mechanism can achieve fewer transmissions and offer more energy-efficient communications for wireless edge IoT applications.

A novel slot scheduling technique for duty-cycle based data transmission for wireless sensor network

The duty cycling process involves turning a radio into an active and dormant state for conserving energy. It is a promising approach for designing routing protocols for a resource-constrained Wireless Sensor Networks (WSNs). In the duty cycle-based WSNs, the network lifetime is improved and the network transmission is increased as compared to conventional routing protocols. In this study, the active period of the duty cycle is divided into slots that can minimize the idle listening problem. The slot scheduling technique helps determine the most efficient node that uses the active period. The proposed routing protocol uses the opportunistic concept to minimize the sender waiting problem. Therefore, the forwarder set will be selected according to the node's residual active time and energy. Further, the optimum routing path is selected to achieve the minimum forwarding delay from the source to the destination. Simulation analysis reveals that the proposed routing scheme outperforms existing schemes in terms of the average transmission delay, energy consumption, and network throughput.

Adaptively Prioritizing Candidate Forwarding Set in Opportunistic Routing in Vanets

Adaptively Prioritizing Candidate Forwarding Set in Opportunistic Routing in Vanets

Adaptively Prioritizing Candidate Forwarding Set in Opportunistic Routing in Vanets

Adaptively Prioritizing Candidate Forwarding Set in Opportunistic Routing in Vanets

The Network-Based Candidate Forwarding Set Optimization for Opportunistic Routing

In wireless multi-hop networks, the opportunistic routing has advantages on packet delivery probability over deterministic routing. For reducing the transmission delay and duplicate transmission in opportunistic routing, the candidate forwarding set (CFS) optimization approach is proposed. Since the previous node-based approaches have disadvantages on improving the performance of opportunistic routing, we propose the network-based approach to address these disadvantages, named the Delay and Duplicate transmission Avoid CFS optimization algorithm, shorted as DDA. In DDA, the nodes in CFS are divided into different fully connected relay networks. For the forwarding nodes in CFS, more than one relay networks can be constructed and only one can be chosen as the final relay network. So, first, we propose the fully connected relay network recognition algorithm to judge whether the chosen network is fully connected or not. Next, the properties of these networks are investigated. Then, based on the multi-attribution decision making (MADM) theory, and taking the packet delivery probability (between sender and relay networks), the transmission delay, and the forwarding priorities of nodes into account, the DDA chooses the most appropriate relay network. The nodes in this relay network are selected as the final forwarding nodes. Based on these innovations, the transmission delay and duplicate transmission are reduced while the efficiency of the original opportunistic routing algorithms is kept. The simulation results illustrate the effectiveness of the network-based DDA algorithm.

Survey on Opportunistic Routing Protocols in Multihop Wireless Networks

Routing is portrayed as one of the most important prevailing challenges in research with reference to multi-hop networks in a wireless environment. Opportunistic routing (OR) protocol is an emerging area related to research, due to the improvement in communication reliability, compared to the traditional routing models. The major perception related to OR is to determine a group of neighboring node candidates, named as a candidate set using the advantages of broadcast capability of the wireless medium thereby to collaboratively transmit data packets towards the destination using the coordination of the forwarded candidate set. The design and performance of OR protocols over multi-hop wireless networks mainly depend on the processes of forwarding selection of candidates and assignment of priorities. Therefore, the researchers have designed and developed several different algorithms for those OR processes. In this paper, following a short outline on traditional routing and OR protocols, metrics involved in the design of existing OR protocols, classification of OR based protocols, and hurdles in the design of OR protocols over multi-hop wireless networks are examined. More precisely, the OR protocols are divided into two categories, based on the forwarding candidate set selection and forwarding candidate coordination methods. Furthermore, the most significant challenges of OR protocol design, such as prioritization of forwarding candidates, utilizing the cross-layer approach for candidate coordination, and achieving the quality of service also investigated.

QoS-aware routing and traffic management in multi-flow opportunistic routing

Opportunistic routing (OR) is a new routing paradigm in which the next hop forwarders are not fixed. A group of network nodes called forwarder set is considered as potential forwarders from which the next hop will be selected. Although OR can improve network performance, network resources are allocated to the flows, regardless of their quality-of-service (QoS) needs. This paper proposes a QoS-aware opportunistic routing that considers QoS levels of the flows in passing them over appropriate paths. To achieve this goal, we propose a method that selects and prioritizes the forwarder set based on the flow's QoS levels. This policy leads to a more uniform distribution of traffic in the network. Consequently, the average queue length, the average queuing delay, and packet loss are reduced. The simulation results imply that the proposed algorithm makes traffic distribution more uniform so that the network performance is improved in terms of average throughput and end-to-end delay.

PRIB-CDS: An Energy Efficient Low Duty Cycle Broadcasting Scheme for Wireless Sensor Network

Low duty cycling is a widely adapted technique to conserve energy in the most used Medium Access Control (MAC) protocols in Wireless Sensor Networks (WSN). But such low duty cycle-based MAC protocols perform poorly under broadcast traffic as they suffer from redundant retransmission and maximization of relay nodes problems. Addressing these issues is critical, as the advent of IoT and ubiquitous computing applications has increased the demand for broadcast support. Our previous work, Preamble based Receiver Initiated Broadcasting MAC (PRIB-MAC) performed well in most parameters under broadcast traffic, but it had scope for improvement in reducing the number of transmissions. In this paper, we propose the PRIB-Connected Dominating Set (PRIB-CDS), built on top of PRIB-MAC with the addition of dynamic forwarding technique by forming a forwarding set with the help of Greedy algorithm. The simulation results of our proposed PRIB-CDS algorithm shows that it has reduced the number of transmissions significantly as it reduces forwarding nodes and balances the energy between the nodes to avoid re-broadcasting the data.

Link-Correlation-Aware Opportunistic Routing in Low-Duty-Cycle Wireless Networks.

In low-duty-cycle wireless networks with unreliable and correlated links, Opportunistic Routing (OR) is extremely costly because of the unaligned working schedules of nodes within a common candidate forwarder set. In this work, we propose a novel polynomial-time node scheduling scheme considering link correlation for OR in low-duty-cycle wireless networks (LDC-COR), which significantly improves the performance by assigning nodes with low correlation to a common group and scheduling the nodes within this group to wake up simultaneously for forwarding packets in a common cycle. By taking account of both link correlation and link quality, the performance of the expected transmission count (ETX) is improved by adopting the LDC-COR protocol. As a result, the energy consumption of low-duty-cycle OR is significantly reduced. LDC-COR only requires the information of one-hop neighboring nodes which introduces minimal communication overhead. The proposed LDC-COR bridges the gap between the nodes’ limited energy resource and the application lifetime requirements. We evaluate the performance of LDC-COR with extensive simulations and a physical wireless testbed consisting of 20 TelosB nodes. The evaluation results show that both transmission efficiency and energy consumption of low-duty-cycle OR are significantly improved with only a slight increase of end-to-end delay.

Void Avoidance Opportunistic Routing Protocol for Underwater Wireless Sensor Networks.

Much attention has been focused lately on the Opportunistic Routing technique (OR) that can overcome the restrictions of the harsh underwater environment and the unique structures of the Underwater Sensor Networks (UWSNs). OR enhances the performance of the UWSNs in both packet delivery ratio and energy saving. In our work; we propose a new routing protocol; called Energy Efficient Depth-based Opportunistic Routing with Void Avoidance for UWSNs (EEDOR-VA), to address the void area problem. EEDOR-VA is a reactive OR protocol that uses a hop count discovery procedure to update the hop count of the intermediate nodes between the source and the destination to form forwarding sets. EEDOR-VA forwarding sets can be selected with less or greater depth than the packet holder (i.e., source or intermediate node). It efficiently prevents all void/trapped nodes from being part of the forwarding sets and data transmission procedure; thereby saving network resources and delivering data packets at the lowest possible cost. The results of our extensive simulation study indicate that the EEDOR-VA protocol outperforms other protocols in terms of packet delivery ratio and energy consumption.

Geographical and Topology Control-Based Opportunistic Routing for Ad Hoc Networks

The opportunistic routing has great advantages on improving packet delivery probability ( ${P}_{\textit {sc}}$ ) between the source node and candidate forwarding set. For improving ${P}_{\textit {sc}}$ and reducing energy consumption and network interference, in this paper, we propose an efficient and reliable transmission power control-based opportunistic routing (ERTO) for wireless ad hoc networks. In ERTO, the network interference and fading channel, which are critical to routing performance but not considered in previous works, are investigated during the prediction of ${P}_{\textit {sc}}$ . The ${P}_{\textit {sc}}$ , the expected energy consumption, and the relationship between transmission power and node degree are applied to optimize the transmission power and forwarding node degree jointly. For improving routing effectiveness and reducing computational complexity, we introduce multi-objective optimization and Pareto optimal into ERTO. During the routing process, nodes calculate the optimal transmission power and forwarding node degree according to the properties of Pareto optimal solution set. Based on these innovations, the energy consumption, the transmission delay, and the network throughput have been improved greatly in ERTO compared with previous work. For instance, when the number of nodes is 120, the network throughput of ERTO is 1.41, 1.42, and 2.63 times larger than that in EEOR, TCOR, and ExOR, respectively.

GCORP: Geographic and Cooperative Opportunistic Routing Protocol for Underwater Sensor Networks

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.

A Dynamic Routing Path Reduction Protocol in Underwater Wireless Sensor Network

Recently, underwater wireless sensor networks (UWSNs) have emerged as a promising networking technique for various underwater applications. An energy efficient routing protocol plays a vital role in data transmission and practical applications. However, due to the specific characteristics of UWSNs, such as dynamic structure, narrow bandwidth, rapid energy consumption, and high latency, it is difficult to build routing protocols for UWSNs. In this paper, We propose a location aware opportunistic routing algorithm for under water communication. We analyse three main problems in under water communication; forwarding set selection forwarding set ranking to handle FSR problem, void handling method to handle the communication void (CV) and overhear and suppression procedure to deal with duplicate forwarding suppression (DFS) problems. The importance of the work is that it will provide an energy efficient pressure based opportunistic routing algorithm for wireless sensor network (UWSN). The routing protocol has been implemented in the ns2-AqaSim simulator and testbed for measurement of the performance metrics of the UASN. The simulation results showed that the novel routing method throughput has increased by 16%, 33%, and 55% when compared with SUN, VBF and DF method. It can effectively improve the throughput of nodes, balance positioning performance as well as energy use efficiency, and optimize the positioning result of UWASN.

Delay-tolerant routing and message scheduling for CR-VANETs

Cognitive radio vehicular ad hoc networks (CR-VANETs) can solve the problem of the limited spectrum resource and improve the vehicle-to-vehicle (V2V) communication efficiency. Nevertheless, the fast moving characteristic of vehicles and the occasional sparse density of vehicles lead to the intermittent CR-VANETs. Recent literature of routing in CR-VANETs focuses on a fully interconnected environment yet fails to address solutions for non-real-time applications. To fill this gap, we propose the delay-tolerant routing and message scheduling (DTRM) schemes for non-real-time applications, aiming to maximize the delivery ratio and decrease the delivery overhead in CR-VANETs. First, we propose a routing scheme that builds a concurrent forwarding set and designs a forwarding strategy. In this set, we select relay candidates by considering both the CR channel availability and the V2V contact duration. Moreover, we evaluate the priority of the relay candidate to provide a reliable forwarding strategy. Second, based on the routing scheme, we propose a message scheduling scheme that combines an optimized-binary-tree replication algorithm and a buffer management policy. The proposed algorithm can spread messages and terminate the replication process quickly. The buffer management policy facilitates the tradeoff between the delivery ratio and the delivery overhead, taking into consideration the node priority, the message tag, and the message remaining time-to-live. Simulation results show that DTRM presents a higher packet delivery ratio and a lower overhead ratio than the counterparts. It presents on average gains of 25.1% and 10.9% in terms of delivery ratio and overhead ratio, respectively, when compared with four CR-VANET routing schemes. It also presents on average gains of 35.6% and 34.1% in terms of delivery ratio and overhead ratio, when compared with three message scheduling schemes.

Performance evaluation of equivalent forwarding sets in software defined networking

Software-Defined Networking (SDN) allows the forwarding sets to be constructed from forwarding rules which are expressed in the form of a single table or multiple linked tables. To reconcile the forwarding behavior of different flow tables, forwarding sets are converted to canonical form also called as equivalent forwarding set (EFS). In this paper, two EFS conversion approaches: match-field oriented approach (MFA) and action oriented approach (ACA) are verified through performance evaluation in various functional test scenarios. Using the concept of Boolean reasoning, we prove the correctness of conversion from multiple-flow-table (MFT) to its equivalent MFA and ACA. Similarly, from our experiment on Open vSwitch, the performance evaluation showed that the ACA approach which converts a forwarding set into an action-indexed dictionary performed well with the truth-table based expression. The performance evaluation shows that the MFA approach which converts a forwarding set into a match-field-indexed dictionary is easier to implement in real network devices with smaller storage capacities.

Prediction-based energy efficient opportunistic routing protocol in wireless sensor networks

Opportunistic routing is a most promising routing method for improving the network lifetime and throughput of wireless sensor networks (WSN). It utilises the broadcast nature of WSN, that allows to select and prioritise a node from the potential forwarder set as next-hop forwarder. The design of energy efficient routing protocol becomes one of the major concern in WSN, due to limited battery power of a sensor node. The common energy loss reasons of existing routing protocols are: 1) packets may travel through a specific set of sensor nodes will drain out a battery energy very soon; 2) packets discard will create a packet retransmission. Opportunistic routing broadcast nature will avoid packet retransmission. The proposed energy efficient Markov prediction-based opportunistic routing (EEMPOR) protocol uses the following metrics to select and prioritise the energy efficient nodes namely, number of transactions of a node and residual energy of a node. Then proposed protocol shows that Markov prediction-based opportunistic routing protocol provides better network performance than non-prediction-based method. Simulation results show, that the proposed protocol outperforms the existing OR in terms of consumed energy, residual energy, network lifetime, and throughput.

PREDICTION BASED ENERGY EFFICIENT OPPORTUNISTIC ROUTING PROTOCOL IN WIRELESS SENSOR NETWORKS

Opportunistic routing is a most promising routing method for improving the network lifetime and throughput of wireless sensor networks (WSN). It utilises the broadcast nature of WSN, that allows to select and prioritise a node from the potential forwarder set as next-hop forwarder. The design of energy efficient routing protocol becomes one of the major concern in WSN, due to limited battery power of a sensor node. The common energy loss reasons of existing routing protocols are: 1) packets may travel through a specific set of sensor nodes will drain out a battery energy very soon; 2) packets discard will create a packet retransmission. Opportunistic routing broadcast nature will avoid packet retransmission. The proposed energy efficient Markov prediction-based opportunistic routing (EEMPOR) protocol uses the following metrics to select and prioritise the energy efficient nodes namely, number of transactions of a node and residual energy of a node. Then proposed protocol shows that Markov prediction-based opportunistic routing protocol provides better network performance than non-prediction-based method. Simulation results show, that the proposed protocol outperforms the existing OR in terms of consumed energy, residual energy, network lifetime, and throughput.