Store-carry-forward Research Articles

SDN-based reliable emergency message routing schema using Digital Twins for adjusting beacon transmission in VANET

Digital Twin (DT) has revolutionized the contextualized digital environment. This advancement enables real-time monitoring and simulation of events, leading to more effective decision-making. In smart transportation, DT plays a crucial role in enhancing various aspects of road decision-making, including optimizing routing decisions for Emergency Message (EM) forwarding in Vehicular Ad hoc Networks (VANETs). In this study, DT has integrated with cutting-edge technologies such as Software-Defined-Network (SDN) and geographically distributed computing (fog computing) to elevate the position-based routing behavior in two directions: selecting the optimal next-hop and taking control of periodic messages (beacon transmission). The nature of routing decisions can be complex due to constant movement and frequent position changes of vehicles in the VANET system. Merely selecting the next-hop vehicle without considering its stability and predictability can result in suboptimal routing choices. To this end, SDN based on Reliable Emergency Message Routing Schema (SDN-REMR) is introduced. This schema utilizes DT and aims to leverage the behaviors of moving vehicles to enhance the delivery of EM by providing a reliable routing mechanism. To eliminate unstable neighbors from the list of potential next-hops, SDN-REMR forecasts the relative positions of surrounding vehicles using Euclidean distance and position information. Moreover, SDN-REMR uses the movement information collected from vehicles (such as position, speed, and power consumption) to reduce the possibility of a link disruption and select the best next-hop for reliable communication. SDN-REMR enables the Store-Carry-Forward (SCF) approach to ensure packets are successfully forwarded to the destination, even in challenging network conditions. This control strategy aims to strike a balance between maintaining reliable communication and minimizing congestion in the network. The experimental results prove that there are 42.6%, 76.22%, 76.22%, and 22.2% enhancement in terms of network throughput, total delivered packets, number of dropped packets, and routing overhead.

Towards Delay Tolerant Networking for Connectivity Aware Routing Protocol for VANET-WSN Communications

Vehicular Ad Hoc Networks (VANETs) are increasingly playing a fundamental role in improving driving safety. However, VANETs in a sparse environment may add risk to driving safety. The probability of a low density of vehicles in a rural area at midnight is very high. Consequently, the packet will be lost due to the lack of other vehicles, and the arrival of the following vehicles in the accident area is unavoidable. To overcome this problem, VANET is integrated with Wireless Sensor Network (WSN). The most challenging features of VANETs are their high mobility. This high mobility causes sensor nodes to consume most of their energy during communication with other nodes, leading to frequent network disconnectivity. With the evolution of VANET and WSN, the Store/Carry-Forward (SCF) paradigm has emerged as an exciting research area in the Delay Tolerant Networks (DTNs) to solve network disconnectivity. This paper proposes the Energy-Mobility-Connectivity aware routing protocol (EMCR) for a hybrid network of VANET-WSN. A comprehensive performance analysis that considers realistic propagation models and real city scenario traffic is performed in NS3. The simulation results show that the SCF mechanism is essential in the EMCR protocol to maximize the delivery ratio and minimize energy consumption and overhead.

Performance Analysis of Energy Optimized LTE-V2X Networks for Delay Sensitive Real-Time Services

Energy-efficient relaying technology in multi-hop data transmission can help the challenges faced in cellular Vehicle-to-Everything (cellular-V2X) communication. However, due to high demand of emergency service requirements of the systems such as Public Protection and Disaster Relief (PPDR), National Security and Public Safety (NSPS), Intelligent Transport System (ITS) etc., least energy consumed user equipment (UEs)/Vehicular-UEs are required which can either run real-time applications or relay the application data. To support these scenarios, we present a high way based system model in rural area and enhance its scope for applying single-hop direct, relay assisted multi-hop cellular-V2X and Store-CarryForward (SCF) modes of uplink data transmission. We compare the performance of three modes of transmissions in terms of overall energy consumption and overall transmission delay with specific delay constraints of VoIP and video applications. With the varying cell radius and irrespective type of applications, our numerical results, validated with ns-3 show that, least energy is always consumed in SCF mode due to its inherent property but applications suffer a lot due to high delay incurred whereas singlehop direct mode shows the reverse. When compared with cellular-V2X mode, overall transmission delay for single-hop direct mode is acceptable within cell radius 600m but beyond that, relay assisted multi-hop cellular-V2X mode always outperforms (with low latency and moderate energy consumption).

Energy-efficient relaying technology in multi-hop data transmission can help the challenges faced in cellular Vehicle-to-Everything (cellular-V2X) communication. However, due to high demand of emergency service requirements of the systems such as Public Protection and Disaster Relief (PPDR), National Security and Public Safety (NSPS), Intelligent Transport System (ITS) etc., least energy consumed user equipment (UEs)/Vehicular-UEs are required which can either run

There are many security models for computer networks using a combination of Intrusion Detection System and Firewall proposed and deployed in practice. In this paper, we propose and implement a new model of the association between Intrusion Detection System and Firewall operations, which allows Intrusion Detection System to automatically update the firewall filtering rule table whenever it detects a weirdo intrusion. This helps protect the network from attacks from the Internet.

Energy-Saving Data Aggregation for Multi-UAV System

In a multi-UAV system, some collected data should be transmitted to relevant UAVs or ground station for processing when energy resources are insufficient or computation consumption is large. In this paper, we researched the energy-saving strategies for data aggregation on the combination of store-carry-forward (SCF) routing and hop-by-hop routing, which are suitable for large-scale multi-UAV networks, and proposed Single Coalition Strategy (SCS) and Coalition Formation Strategy (CFS) based on the coalition game theory. In SCS, all source UAVs transmit data individually or can form a coalition. The coalition aggregates all data to a ferry UAV for transmission, the ferry choose between SCF routing mode and hop-by-hop routing mode with the help of predicted energy-cost calculation. In CFS, all source UAVs form a coalition structure by coalition formation game (CFG) algorithm according to data amount, location, and network topology. Each coalition can aggregate data to its own ferry, and then the ferry transmits data in the optimized mode. We analyze the performance of SCS and CFS by simulations, the average transmission energy consumption of a UAV in SCS and CFS are about 30% of hop-by-hop routing mode. Based on the results, we recommend that SCS should be used when the application scenario is small and the number of UAVs is limited. In the case where the application scenario is great and the number of UAVs is large, CFS with the Utilitarian order and limited message propagation hops is recommended.

Detection of Multiple Attackers and Provide Security for UAV Networks

Remote controlled aerial vehicle networks haven’t received right smart analysis attention. Specifically, security problem area unit is a serious concern as a result of such networks that carry very important data square measure at risk of numerous attacks. In our projected system to style and implemented a novel Location –Aided Delay Tolerant Routing Protocol(LADTR) with intrusion detection and response scheme, that operates at the UAV(Unmanned Aerial Vehicle)and ground station level, to find spiteful anomalies that menace the network. And conjointly UAV networks to be used in post-disaster operation, which combined with Store Carry Forward (SCF) techniques. During this theme, a group of detection and response techniques square measure projected to observe the UAV behaviors and reason them into appropriate list (normal, abnormal, suspect, malicious) in keeping with the detected cyber attack. Our simulation result make sure that the projected theme performs well in terms of attack detection even with an oversized range of UAVs and attackers since it exhibits a high detection rate , an occasional range of false positives, and prompt detection overhead and conjointly improve the packet delivery magnitude relation, network time period.

RSU-Assisted Traffic-Aware Routing Based on Reinforcement Learning for Urban Vanets

In urban vehicular ad hoc networks (VANETs), the high mobility of vehicles along street roads poses daunting challenges to routing protocols and has a great impact on network performance. In addition, the frequent network partition caused by an uneven distribution of vehicles in an urban environment further places higher requirements on the routing protocols in VANETs. More importantly, the high vehicle density during the traffic peak hours and a variety of natural obstacles, such as tall buildings, other vehicles and trees, greatly increase the difficulty of protocol design for high quality communications. Considering these issues, in this paper, we introduce a novel routing protocol for urban VANETs called RSU-assisted Q-learning-based Traffic-Aware Routing (QTAR). Combining the advantages of geographic routing with the static road map information, QTAR learns the road segment traffic information based on the Q-learning algorithm. In QTAR, a routing path consists of multiple dynamically selected high reliability connection road segments that enable packets to reach their destination effectively. For packet forwarding within a road segment, distributed V2V Q-learning (Q-learning occurs between vehicles) integrated with QGGF (Q-greedy geographical forwarding) is adopted to reduce delivery delay and the effect of fast vehicle movements on path sensitivity, while distributed R2R Q-learning (Q-learning occurs between RSU units) is designed for packet forwarding at each intermediate intersection. In the case of a local optimum occurring in QGGF, SCF (store-carry-forward) is used to reduce the possibility of packet loss. Detailed simulation experimental results demonstrate that QTAR outperforms the existing traffic-aware routing protocols, in terms of 7.9% and 16.38% higher average packet delivery ratios than those of reliable traffic-aware routing (RTAR) and greedy traffic-aware routing (GyTAR) in high vehicular density scenarios and 30.96% and 46.19% lower average end-to-end delays with respect to RTAR and GyTAR in low vehicular density scenarios, respectively.

Is Hop-by-Hop Always Better Than Store-Carry-Forward for UAV Network?

As energy supply on Unmanned Aerial Vehicle (UAV) is limited, energy efficient data transmission in UAV networks would be of great concern to the researchers. Nevertheless, UAV networks exhibit strong dynamic nature compared to ordinary Mobile Ad hoc Network (MANET), it is not rare that some nodes will be disjoint from other nodes from time to time. Under such circumstance, ordinary hop-by-hop routing schemes can not be used anymore, for there is no route existed from source to destination. Some solutions use store-carry-forward (SCF) routing to facilitate end to end data transmission. However, when should we use SCF routing, when we should use hop-by-hop routing if we taking energy into consideration? Is hop-by-hop routing always better than SCF? If it is good or not when the hop-by-hop routing is combined with the SCF routing? All these questions need to be answered. In this paper, we answered above questions by proposing three types of minimum energy consumption models of hop-by-hop routing, and two SCF routing models. We compared all these models and considered four tactics of combination modes for the transmissions in a rotary-wing UAV network. The researches show that two tactics have better performance than other modes in energy saving capabilities by reducing 70% at most with the hop-by-hop routing, and the transmission time of combination modes are in same scale compared with hop-by-hop routing. The two tactics are appropriate for different UAV networks respectively, in which the source UAV can or cannot get the GPS information of relay UAVs in the route. The research conclusion can also be used for the transmissions in a fixed-wing UAV network by modifying the energy consumption models of fixed wing UAV, which is different from rotary wing UAVs.

Cooperative transmission in delay tolerant network

The delay tolerant network (DTN) is an emerging concept, which is used to describe the network, where the communication link may disrupt frequently. To cope with this problem, the DTN uses the store-carry-forward (SCF) transmission mode. With this policy, the messages in the DTN are transmitted based on the nodes' cooperation. However, the nodes may be selfish, so the source has to pay certain rewards for others to get their help. This paper studies the optimal incentive policy to maximize the source's final utility. First, it models the message spreading process as several ordinary differential equations (ODEs) based on the mean-field approximation. Then, it mathematically gets the optimal policy and explores the structure of the policy. Finally, it checks the accuracy of the ODEs model and shows the advantages of the optimal policy through simulation and theoretical results respectively.

The Steady-State Distribution of Rehealing Delay in an Intermittently Connected Highway VANET

A vehicular ad hoc network may suffer from intermittent connectivity. When a network disconnection occurs during message delivery, it can be restored by a temporal relay, i.e., a store-carry-forward (SCF) relay. There have been numerous previous works discussing the rehealing delay, which is the delay required to restore a network disconnection by an SCF relay. However, most of them neglect the dependence of the restoration of a network disconnection on that of the previous one. As a result, their results would become invalid when a long-distance delivery of messages is necessary. To address this problem, we discuss how the restoration of a network disconnection can be affected by that of the previous one, from which an embedded Markov chain is developed to obtain the steady-state probability distribution of rehealing delay. Simulation results show that our analysis is highly accurate, as compared to previous works.

Location-Aided Delay Tolerant Routing Protocol in UAV Networks for Post-Disaster Operation

Wireless communication is essential for search and rescue operations in the aftermath of natural disasters. In post-disaster scenarios, unmanned aerial vehicles (UAVs) can be used to capture image and video data from the disaster area and transfer the data to a ground station, owing to their rapid mobility. However, packet forwarding is a challenge because of unstable links and intermittent connectivity in highly dynamic UAV networks. In this paper, we propose a location-aided delay tolerant routing (LADTR) protocol for UAV networks for use in post-disaster operations, which exploits location-aided forwarding combined with a store–carry–forward (SCF) technique. Ferrying UAVs are introduced to enable an efficient SCF, and this is the first attempt at introducing and using ferrying UAVs for routing in UAV networks, to the best of our knowledge. Ferrying UAVs improve the availability of connection paths between searching UAVs and the ground station, thus reducing end-to-end delays and increasing the packet delivery ratio. Future UAV locations are estimated based on the location and speed of UAVs equipped with a global positioning system. The forwarding UAV node predicts the position of the destination UAV node and then decides where to forward. The proposed LADTR ensures that the contact rate between UAV nodes remains high, which enables a high packet delivery ratio, and ensures single-copy data forwarding to avoid replication of each message. Our performance study shows that the proposed LADTR outperforms the four typical routing protocols reported in the literature in terms of packet delivery ratio, average delay, and routing overhead.

An intelligent approach in delay tolerant network routing

Delay tolerant networks (DTNs) are wireless intermittent networks. DTNs have different applications such as wildlife tracking, military, and space searching. Conventional mobile ad hoc network (MANET) routing protocols are not efficient in these networks because of intermittency. DTNs use store-carry-forward (SCF) for data transferring. In SCF, nodes store the messages and carry them until finding appropriate nodes for forwarding. Message replication greatly helps to improve the delivery ratio while increasing overhead. This paper examines the use of intelligent routing to choose nodes that have more probability to reach their destination. This will help to increase the message delivery ratio while reducing overhead. The proposed method, SADTN, uses simulated annealing (SA), which has shown successful results in finding global minimal, to find the next hop. Comparison of the proposed method to previously implemented methods such as epidemic routing (ER) and Probabilistic ROuting Protocol using History of Encounters and Transitivity (PROPHET), which are usually used for evaluating other methods, shows increasing message delivery ratio and decreasing overhead in SADTN. Overhead in SADTN has on average fallen to 0.01484 of ER and 0.02325 of PROPHET. This is a great advantage of SADTN.

A Survey of Spray-and-Wait Routing Protocol in Pocket Switched Network

Store-Carry-Forward (SCF) approach provides a new paradigm to route messages in Pocket Switched Network (PSN). In this approach, a router node will store and carry the messages while roaming from one place to another place. Whenever the node meets a destination node, the routing messages will be immediately forwarded to the destination node. Unfortunately, this approach is hampered by the lack of infrastructure in the network, which directly effects on the quality of interconnection among nodes. Therefore, end-to-end connection between the source node and the destination node is difficult to be obtained. Many approaches have been proposed to overcome this problem. Indeed, several routing protocols have also considered these approaches for distributing their routing messages. However, a paper survey that comprehensively summarizes the proposed solutions are difficult to be found in the literature. This leads not easy to understand problems, solutions and future works for these approaches in the network. This paper presents a comprehensive survey to track the development of Spray-and-Wait (SNW) routing protocol, one of the most popular SCF-based routing protocol in PSN.

End-to-End Performance for SCF-Based Vehicular Routing Over Multiple Communication Gaps

In Vehicular Ad Hoc Networks (VANETs), there are generally very few communicating vehicles along a routing path in areas with low traffic density. Existing schemes based on the Store-Carry-Forward (SCF) technique utilize a moving vehicle to bridge the communication gap between two disconnected vehicles on the opposite lane. This letter investigates network performance over multiple communication gaps in SCF-based vehicular routing. To investigate the influence of the transmission range on the end-to-end delivery delay, we develop an analytical model to quantify the performance in terms of the Laplace transform of the end-to-end delay via SCF-based vehicular routing. Extensive simulation results are presented to validate the proposed model.

An Efficient Emergency Message Broadcasting Scheme in Vehicular Ad Hoc Networks

Broadcasting of emergency message (EM) in the vehicular Ad hoc networks (VANETs) plays a significant role in safety applications, which require immediate broadcasting of EM to the relevant vehicles located in the risk zone (RZ). This paper proposes an efficient emergency message broadcasting (EEMB) scheme in VANETs. This scheme aims at avoiding multiple accidents and reducing traffic jams by broadcasting EM at high speed and with low overhead. When an accident takes place, the crashed vehicle (CV) will choose the best relayer(s) and broadcast the EM. The relayer will also choose the best next relayer(s) and rebroadcast the EM further. This process continues until the EM covers the whole RZ. The EEMB scheme reduces the overhead caused by beacons by using the prediction method. Our proposed scheme also overcomes the network fragmentation problem either by choosing the vehicles moving in the opposite direction as the relayer(s) if there are no vehicles in the same direction or by using the store-carry-forward (SCF) mechanism when there are no vehicles moving in both directions. The simulation results have shown that the proposed scheme has better performance in terms of the risk zone latency (RZL) and the beacons overhead (BCO).

도심의 차량 네트워크에서 긴급 메시지 전파를 위한 효율적인 브로드캐스트 기법

본 논문은 차량이 사고가 발생하였을 때, 사고 차량이 가까이에 있는 주위 차량에 긴급메시지를 전파하여, 다른 차량의 운전자들이 사고지점을 인지하고 회피할 수 있도록 효과적이고 빠른 브로드캐스트 기법에 관하여 기술하였다. 본 논문에서는 GPS(Global Position System)가 장착된 도심환경의 차량 네트워크에서 긴급 메시지를 빠르게 전파하는 방법을 제안한다. 전송 차량은 연속적이고 효과적인 메시지 전파를 위해 가장 멀리 있는 차량을 다음 릴레이 차량으로 미리 선정하고 전파를 하는 기법을 제안한다. 그리고 RSU(Road Side Unit)의 도움 없이 교차로를 인식할 수 있는 알고리즘을 제안하며, 끊어진 네트워크 상황에 대처하기 위해 헬로 메시지를 이용한 SCF(Store-Carry-Forward) 기법을 제안한다. If an accident vehicle propagates emergency messages to other vehicles close to it, the other drivers may realize and avoid the accident spot. In this letter, we propose a broadcast scheme to propagate emergency messages fast in urban VANETs (Vehicular Ad-Hoc Networks) with the help of GPS (Global Position System). In our scheme, a transmitting vehicle chooses the farthest node as the next relay vehicle to propagate emergency messages. And, we suggest an algorithm for intersection recognition and SCF (Store-Carry-Forward) task by taking advantage of periodic hello packets to reduce the propagation time and enhance the delivery ratio.

Routing in Delay/Disruption Tolerant Networks: A Taxonomy, Survey and Challenges

The introduction of intelligent devices with short range wireless communication techniques has motivated the development of Mobile Ad hoc NETworks (MANETs) during the last few years. However, traditional end-to-end based routing algorithms designed for MANETs are not much robust in the challenged networks suffering from frequent disruption, sparse network density and limited device capability. Such challenged networks, also known as Intermittently Connected Networks (ICNs) adopt the Store-Carry-Forward (SCF) behavior arising from the mobility of mobile nodes for message relaying. In this article, we consider the term ICNs as Delay/Disruption Tolerant Networks (DTNs) for the purpose of generalization, since DTNs have been envisioned for different applications with a large number of proposed routing algorithms. Motivated by the great interest from the research community, we firstly review the existing unicasting issue of DTNs because of its extensive research stage. Then, we also address multicasting and anycasting issues in DTNs considering their perspectives. A detail survey based on our taxonomy over the period from 2006 to 2010 is not only provided but also a comparison is given. We further identify the remaining challenges and open issues followed by an evaluation framework proposed for routing in DTNs. Finally, we summarize our contribution with three future research topics highlighted.

Optimized message delivery framework using fuzzy logic for intermittently connected mobile ad hoc networks.

AbstractDue to limited radio transmission range, sporadic node densities and power limitations, mobile ad hoc networks (MANETs) can usually become intermittently connected, thereby data routing process is disrupted in the absence of an end‐to‐end routing path. To this effect, various ‘store‐carry‐forward (SCF)’ routing algorithms have been proposed in the literature that exploit the mobility and storage space of the nodes to deliver messages even if a route never exists. To have a high probability of eventual delivery, flooding‐based or multi‐copy‐based forwarding strategy is adopted by majority of these schemes. Furthermore, in the human‐related environments containing correlated movements, performance is quantified in terms of the probability of the message delivery between any pair of nodes. However, in the multi‐copy case, the conventional individual delivery probability alone fails to address delivery opportunity from other nodes that also carry the same message copies. With this in mind, this paper presents several routing‐related key parameters and accordingly introduces a fuzzy logic‐based delivery framework (FLDF) to select and store messages that have higher delivery preference in the future. In the proposed mechanism, FL, which has the fundamental ability to deal with imprecise or uncertain information caused by intermittent connectivity as well as mobility randomness, is employed to handle the message evaluation and selection. Simulation results demonstrate the enhanced delivery performance offered by the proposed FLDF compared with the existing schemes. Copyright © 2008 John Wiley & Sons, Ltd.