Delay Tolerant Networks Routing Algorithms Research Articles

Space delay-tolerant network routing algorithm based on node clustering and social attributes

Efficient space delay-tolerant network (DTN) routing algorithms have been a hot issue in space network-related research. In this paper, for the problems of high algorithm complexity and high network overhead in space DTN routing algorithms, we introduce a node clustering algorithm and satellite node social attributes in the space DTN routing process and design a spatial delay-tolerant network routing algorithm (CD-SDTN) based on node clustering and social attributes. The algorithm designs the social attributes of the satellite nodes based on the connection frequency of the satellite nodes with the ground station and divides the community using the Circle-k-means algorithm. In the routing process, the center satellite node with the highest activity in the community manages the messages received by the satellite nodes located in the community and plans the forwarding of messages within and between communities. Simulation results show that the CD-SDTN routing algorithm has some advantages in terms of delivery rate, average delay and network overhead compared with Epidemic and Prophet, especially when the number of nodes in the satellite network is large.

A delay tolerant network routing algorithm based on multi‐step double Q‐learning

AbstractDelay tolerant networks (DTNs) refer to a kind of novel wireless mobile network, where there is no constant end‐to‐end connection between network nodes due to frequent movement, sparse distribution and limited communication range of nodes. Instead of the traditional store‐forward routing strategy, in DTNs, the new store‐carry‐forward routing strategy is adopted for data transmission. Therefore, how to select the best next‐hop node among network nodes is the main challenge of the routing in DTNs. To this end, here, a k‐step double Q‐learning routing (K‐DQLR) algorithm is proposed, which integrates the multi‐step and double Q‐learning algorithms to make an unbiased, accurate and efficient routing decision in DTNs. Besides, a new dynamic reward mechanism is proposed, which combines the number of routing hops and the node centrality to adopt the dynamic network environment of DTNs. The simulation results show that K‐DQLR can significantly increase the delivery ratio while reducing the delivery delay and overhead compared with the related state‐of‐the‐art routing protocols of DTNs.

Vehicular delay tolerant network routing algorithm based on trajectory clustering and dynamic Bayesian network

Vehicular delay tolerant network routing algorithm based on trajectory clustering and dynamic Bayesian network

A DTN oriented adaptive routing algorithm based on node load

In recent years, Delay Tolerant Networks (DTN) have received more and more attention. At the same time, several existing DTN routing algorithms generally have disadvantages such as poor scalability and inability to perceive changes in the network environment. This paper proposes an AdaptiveSpray routing algorithm. The algorithm can dynamically control the initial maximum message copy number according to the cache occupancy rate of the node itself, and the cache occupancy rate is added as an impact factor to the calculation of the probability of each node meeting the destination node. In the forwarding phase, the node will first compare the meeting probability of itself and the meeting node to the destination node, and then choose different forwarding strategies. The simulation shows that the AdaptiveSpray algorithm proposed in this paper has obvious advantages compared with the existing routing algorithms in terms of message delivery rate and average delay.

Analysis of health informatics and bioinformatics connectivity modeling

Health informatics and bioinformatics are closely linked, but the overlapping literature search rate of the analysis methods is low due to the connectivity analysis model. Therefore, a health informatics and bioinformatics connectivity modeling analysis based on a delay-tolerant network routing algorithm is proposed. The analysis is conducted for the topics of both health informatics and bioinformatics disciplines, and a reasonable design of citation measures is designed. The first step in describing the connection between the two disciplines using citation analysis is to extract multidimensional descriptive vectors for the disciplines as a basis for connectivity analysis. The connectivity analysis model is designed with the core of the tolerance network routing algorithm to determine the connectivity of disciplines by detecting the citation overlap between two disciplines. Finally, the connectivity is described by outputting the co-occurrence knowledge structure between disciplines through co-occurrence analysis. The experimental results show that the proposed method improves the completeness rate by 36.6% and 39.2% compared with the conventional connectivity modeling analysis method, which indicates that the proposed method reveals more comprehensive connectivity analysis results.

Internet of Planets (IoP): A New Era of the Internet

Internet of Planets (IoP) is a concept that enables solar planets to communicate with each other using the Internet. While there is a plethora of research on IoP, the delay-tolerant network (DTN) has emerged as the most advanced technology in recent years. DTN is an asynchronous networking technology that has been deployed for the networking environment in which steady communication paths are not available, and therefore, it stores receiving data in a data storage and forward them only when the communication links are established. DTN can be applied to sensor networks and the mobile ad-hoc network, as well as space communication that supports data transmissions among satellites. In DTN networking environments, it is crucial to secure a scheme that has relatively low routing overhead and high reliability to achieve efficiency. Thus, this article proposes a time (delay) information based DTN routing scheme, which is able to predict routing paths for achieving efficient data transmissions among the nodes that have comparatively periodic moving patterns. The results of the proposed DTN routing algorithm using NS-3 simulation tools indicate satisfied levels of routing performance in comparison with the existing DTN algorithm.

DTN-Balance: A Forwarding-Capacity and Forwarding-Queue Aware Routing for Self-organizing DTNs

In delay-tolerant networks (DTNs), intermittent network connectivity and lack of global system information pose serious challenges to achieve effective data forwarding. Most state-of-the-art DTN routing algorithms are based on hill-climbing heuristics in order to select the best available next hop to achieve satisfactory network throughput and routing efficiency. An adverse consequence of this approach is that a small subset of good users take on most of the forwarding tasks. This can quickly deplete scarce resources (e.g. storage, battery, etc.) in heavily utilized devices which degrades the network reliability. A system with a significant amount of traffic carried by a small number of users is not robust to denial of service attacks and random failures. To overcome these deficiencies, this paper proposes a new routing algorithm, DTN-Balance, that takes the forwarding capacity and forwarding queue of the relay nodes into account to achieve a better load distribution in the network. For this, we defined a new routing metric called message forwarding utility combining nodal available bandwidth and forwarding workload. Applying small world theory, we impose an upper bound on the end-to-end hop count that results in a sharp increase in routing efficiency. Queued messages in a forwarding node are arranged by DTN-Balance based on message dropping utility metric for a more intelligent decision in the case of a message drop. The performance of our method is compared with that of the existing algorithms by simulations on real DTN traces. The results show that our algorithm provides outstanding forward efficiency at the expense of a small drop in the throughput.

An adaptive multiple spray-and-wait routing algorithm based on social circles in delay tolerant networks

In delay tolerant networks (DTN), the social attributes of nodes show long-term stability, which can be leveraged for more effective routing. In this paper, we first present a novel way of constructing social circles based on the node clustering phenomena in DTN. Then, considering that the forwarding capability of nodes is significantly different, we propose a spray strategy based on social circles (named SC-SS) to improve the spray-and-wait routing algorithm. SC-SS selects the next hop based on the social circle of nodes in the spray phase. Instead of fixing the initial number of copies, we design an adaptive multiple spray-and-wait routing algorithm based on social circles (named SC-AMSW) to further improve the performance of SC-SS. SC-AMSW selectively sprays messages multiple times in the wait phase and determines an appropriate number of redundant message copies based on delivery predictability. We conduct extensive simulations to confirm the effectiveness of our proposed routing algorithms in DTN.

Vehicular Delay Tolerant Network Routing Algorithm Based on Bayesian Network

Delay Tolerant Networks (DTNs) are novel wireless mobile networks, which suffer from frequent disruption, high latency, and the lack of a complete path from source to destination. Vehicular Delay Tolerant Network (VDTN) is a special type of DTNs with vehicles as nodes. In VDTN, most nodes have specific movement patterns, however, traditional routing algorithms in DTNs do not take this characteristic into considerations very well. In this paper, a new routing algorithm based on Bayesian Network (BN) is proposed to construct the prediction model, which intends to predict the movement patterns of nodes in the real VDTN scenarios. Firstly, a comprehensive BN model is established, where more attributes of nodes are selected to improve the accuracy of the model prediction. Then, considering the complexity of the structure learning problem of BN, a novel structure learning algorithm, K2 algorithm based on Genetic Algorithm (K2-GA), is proposed to search the optimal BN structure efficiently. At last, Junction Tree Algorithm (JTA) is adopted in the inference of BN, which can accelerate the inference process through variable elimination and calculation sharing for large scale BN. The simulation results show that the proposed VDTN routing algorithm based on the BN model can improve the delivery ratio with a minor forwarding overhead.

A data dissemination mechanism based on evaluating behavior for vehicular delay-tolerant networks

Vehicular delay-tolerant networks are widely used in intelligent transport application. Vehicle nodes exchange and share various information in vehicular delay-tolerant networks. However, current delay-tolerant network routing algorithms do not take into account the dynamic characteristic of traffic flow, and they do not effectively resist cyber attacks, such as black hole attack. To address this issue, we propose a data dissemination mechanism for vehicular delay-tolerant networks. In this mechanism, we develop a combined model to estimate the real-time traffic density. Simultaneously, we propose the metrics which include node interaction dispersion, node interaction freshness, node interaction participation, and node interaction contribution to evaluate behavior of nodes. Based on these metrics, a routing method is constructed. In this routing method, a relay node is selected by evaluating communication interaction behaviors among vehicle nodes. Considering the factors of traffic flow density and communication behaviors of vehicle nodes, a message forwarding strategy scheme is built for different traffic density scenarios. Extensive simulations show that the proposed mechanism exhibits superior performance over existing methods in forwarding traffic information and alleviates negative effects from black hole attacks.

Delay Tolerant Network and the Algorithms of DTN Routing

Delay Tolerant Network (DTN) is a new type of network, which is different from traditional TCP / IP communication protocol network. It is suitable for extreme environment where end-to-end communication connection cannot be established stably. Firstly, the characteristics and structure of DTN are analyzed, then the characteristics of nodes in the network are also analyzed. Secondly, the DTN routing problem is explained. Next, the classification of DTN routing algorithms and some classical routing algorithms are introduced. Finally, some other problems of DTN are proposed. The stable operation of the TCP/IP protocol relies mainly on three underlying link features: (1) There is a stable and reliable end-to-end link between the source node and the destination node; (2) The maximum round trip time RTT (Round Trip Time) between any nodes is not long; (3) The probability of message loss during transmission is low [2]. DTN extends the application of IPN to terrestrial mobile communications, emergency communications, underwater communications and wildlife monitoring. DTN can make up for the shortcomings of existing communication networks and realize communication connections in extreme or special environments. In recent years, research on DTN has made great progress. Further in-depth research on the DTN network in the future will inevitably promote and promote network communication.

An Adaptive Spray and Wait Routing Algorithm Based on Quality of Node in Delay Tolerant Network

The Internet of Things is one of the new emerging application domains that require delay tolerant network (DTN) support, where an end-to-end path between the source and the destination may not always exist. Due to the intermittent connectivity of DTN, the design of an efficient routing algorithm is the main challenge. In this paper, we first define a metric called message handling capacity to determine the ability of a node to forward messages. Then, we introduce a concept called connection strength to reflect the connection time between nodes and then integrate the concept into delivery predictability used by Prophet to determine the chance of a node completely delivering a message to the destination. Subsequently, we present a metric called quality of node (QoN), which is calculated by combining the relative weights of the message handling capacity and the improved delivery predictability. Finally, we present an adaptive spray and wait routing algorithm based on QoN (QoN-ASW). The QoN-ASW adaptively allocates the number of message copies between the encountered nodes according to the proportion of quality of node in the spray phase, which avoids the blindness of replica distribution. In addition, a forwarding scheme is implemented in the wait phase, which takes full advantage of encounter opportunities. In the simulation, we demonstrate the efficiency of integrating the connection strength into delivery predictability and compare the QoN-ASW with four existing DTN routing algorithms from four aspects. The simulation results show that the QoN-ASW can significantly improve the delivery rate and reduce the average delay while achieving a relatively low overhead.

Greedyflow: Distributed greedy packet routing between landmarks in DTNs

Delay Tolerant Networks (DTNs) have attracted much research interest recently due to its adaptability in areas without infrastructures. In such scenarios, moving data from one place (landmark) to another place (landmark) is essential for data communication between different areas. However, current DTN routing algorithms either fail to fully utilize node mobility or have additional requirements that cannot be satisfied easily in DTNs. Therefore, in this paper, we propose a distributed greedy routing algorithm, namely GreedyFlow, for efficient packet routing between landmarks in DTNs. GreedyFlow builds a local traffic map and a global landmark map on each node. The local traffic map indicates the node’s knowledge about the amount of traffic (node transition) between landmarks in the area where it primarily visits. The global landmark map shows the distribution of landmarks in the system and is built offline. In packet routing, the global landmark map shows the general packet forwarding direction, while the local traffic map helps determine the next-hop landmark on the fastest path in the forwarding direction. As a result, packets are greedily forwarded toward their destination landmarks. We also propose advanced components to enhance the consistency of local traffic maps and exploit node-based forwarding, both of which help improve the packet routing efficiency. Extensive real trace driven experiments demonstrate the high efficiency of GreedyFlow.

Location-assistant content distribution scheme for emergency rescue

In order to optimize the timeliness and pertinence of message delivery in emergency rescue scenarios and improve the service performance of emergency communications network, we propose a location-assistant content distribution scheme based on delay tolerant network. First of all, considering that the movement patterns of rescue teams tend to follow a predetermined course of action, we design a location-based group mobility model. Due to the intermittent network connectivity and variety of emergency service, a content-classification-based publish/subscribe architecture and a GenericSpray routing algorithm based on the prediction of overlap opportunity in spatio-temporal positions are proposed. Furthermore, we also give a cache management strategy based on the content significance. Since location-assistant content distribution scheme can predict the overlap of activity between rescue teams through the course of action, not only can the number of copy forwarding and message delivery delays be significantly reduced but also the priority delivery of important messages can be ensured by message classification. Simulation experiments show that compared with the traditional delay tolerant network routing algorithm and the classic first-in-first-out caching strategy, location-assistant content distribution scheme improves the performance of message delivery rate, transmission delay, and control overhead significantly.

A Motion and Counting Based-Routing Algorithm for Delay Tolerant Network

Considering the characteristics of Vehicular Ad-hoc Network (VANET), we here propose a Delay-Tolerant Networks (DTN) routing algorithm called Motion and Counting Based-Spray and Seek Routing algorithm (MNCBSS). This algorithm is based upon Spray and Wait Router and describes the method of optimization and specific procedures of the algorithm. Whereafter we perform the simulation over several classic DTN routing algorithms and MNCBSS algorithm, compare the routing algorithms by sketching the statistics and then give the analysis of the different performance of each scheme and eventually demonstrate effectiveness and reliability of the MNCBSS algorithm.

Delay tolerant network: routing issues and performance

Delay tolerant networks (DTNs) are deployed in long distance data communications where delay is permissible like in interplanetary networks (IPNs). For the transfer of messages in a DTN, various routing schemes have been proposed but there has not been an umpteen amount of work related to their comparisons. Therefore, a study of the routing techniques, issues in DTN connectivity and performance analysis of routing algorithms in DTN have been showcased in the current work. This analysis would help the researchers in identifying the most efficient routing scheme amongst well known routing algorithms.

Delay tolerant network: routing issues and performance

Delay tolerant networks (DTNs) are deployed in long distance data communications where delay is permissible like in interplanetary networks (IPNs). For the transfer of messages in a DTN, various routing schemes have been proposed but there has not been an umpteen amount of work related to their comparisons. Therefore, a study of the routing techniques, issues in DTN connectivity and performance analysis of routing algorithms in DTN have been showcased in the current work. This analysis would help the researchers in identifying the most efficient routing scheme amongst well known routing algorithms.

A routing defense mechanism using evolutionary game theory for Delay Tolerant Networks

Delay Tolerant Networks (DTNs) often suffer from intermittent disruption due to factors such as mobility and energy. Though lots of routing algorithms in DTNs have been proposed in the last few years, the routing security problems have not attracted enough attention. DTNs are still facing the threats from different kinds of routing attacks. In this paper, a general purpose defense mechanism is proposed against various routing attacks on DTNs. The defense mechanism is based on the routing path information acquired from the forwarded messages and the acknowledgment (ACK), and it is suitable for different routing schemes. Evolutionary game theory is applied with the defense mechanism to analyze and facilitate the strategy changes of the nodes in the networks. Simulation results show that the proposed evolutionary game theory based defense scheme can achieve high average delivery ratio, low network overhead and low average transmission delay in various routing attack scenarios. By introducing the game theory, the networks can avoid being attacked and provide normal transmission service. The networks can reach evolutionary strategy stable (ESS) under special conditions after evolution. The initial parameters will affect the convergence speed and the final ESS, but the initial ratio of the nodes choosing different strategies can only affect the game process.

Exploiting Small World Properties for Message Forwarding in Delay Tolerant Networks

In Delay Tolerant Networks (DTNs), the connections between mobile nodes are always disrupted and constant end-to-end paths rarely exist. In order to cope with these communication challenges, most existing DTN routing algorithms favour the “multi-hop forwarding” fashion where a message can be forwarded by multiple relay nodes in the hope that one of the employed relay nodes can deliver the message to the destination node. Since aggressively employing relay nodes may incur the intolerable delivery cost in DTNs, it is meaningful to design a cost-efficient routing algorithm that can achieve a high delivery performance. In this paper, we first design a novel delivery metric to measure the forwarding capability of nodes. Then, we utilize small-world properties to design the principles of relay node selection, e.g., limiting the number of relays and finding the appropriate relay nodes, and further develop a cost-efficient social-aware forwarding algorithm called TBSF. Extensive simulations on real mobility traces are conducted to evaluate the performance of TBSF, and the results demonstrate its efficiency and usefulness.

Research Opportunism Delay Tolerant Network Routing Algorithm based on Energy

Research Opportunism Delay Tolerant Network Routing Algorithm based on Energy