Delay Tolerant Networks Routing Algorithms Research Articles

DTN-FLOW: Inter-Landmark Data Flow for High-Throughput Routing in DTNs

In this paper, we focus on the efficient routing of data among different areas in delay tolerant networks (DTNs). In current algorithms, packets are forwarded gradually through nodes with higher probability of visiting the destination node or area. However, the number of such nodes usually is limited, leading to insufficient throughput performance. To solve this problem, we propose an inter-landmark data routing algorithm, namely DTN-FLOW. It selects popular places that nodes visit frequently as landmarks and divides the entire DTN area into subareas represented by landmarks. Nodes transiting between landmarks relay packets among landmarks, even though they rarely visit the destinations of these packets. Specifically, the number of node transits between two landmarks is measured to represent the forwarding capacity between them, based on which routing tables are built on each landmark to guide packet routing. Each node predicts its transits based on its previous landmark visiting records using the order- k Markov predictor. When routing a packet, the landmark determines the next-hop landmark based on its routing table and forwards the packet to the node with the highest probability of transiting to the selected landmark. Thus, DTN-FLOW fully utilizes all node movements to route packets along landmark-based paths to their destinations. We analyzed two real DTN traces to support the design of DTN-FLOW. We deployed a small DTN-FLOW system on our campus for performance evaluation. We also proposed advanced extensions to improve its efficiency and stability. The real deployment and trace-driven simulation demonstrate the high efficiency of DTN-FLOW in comparison to state-of-the-art DTN routing algorithms.

A Survey of Misbehavior Detection Scheme in DTN

The survey tries to review the various problems and their solution in Delay Tolerant Network (DTN) while routing the packets. In this paper, going to discuss and see the overview of various methods used in the DTN. They are simbet and bubble rap which are the DTN routing algorithm and is used for identify the bridge nodes using betweenness centrality and similarity metrics in the network. Then watchdog and pathrater used for detecting the misbehaving nodes in the DTN. Practical incentive protocol (Pi) is used for addressing the selfishness problem in DTN. Secure multilayer credit based incentive scheme (SMART) provide the incentives to the selfish node by using credits in the network.

Exploring an energy-efficient DTN framework supporting disaster management services in post disaster relief operation

In recent years, several investigations have been made on "challenged network" [also known as, delay tolerant network (DTN)] architectures highlighting their advantages and disadvantages. In spite of its inherent shortcomings of unreliability and delay, smart-phone based opportunistic network is gaining immense popularity in the research community due to its applicability in different adverse and extreme communication scenarios where traditional communication infrastructure is either unavailable or incapacitated for a long time. Considerable research has been conducted till date to design efficient network architecture for emergency data dissemination in intermittently connected/challenged networks. Different architectures (ranging from flat to multi-tier) are proposed for implementing opportunistic DTN keeping in view of specific application requirements. However, very few of these proposed architectures have been examined from the perspective of a post disaster communication. Moreover, most DTN architectures are designed by aiming towards increasing delivery probability and reducing latency and as a whole, maximizing network throughput; with very little emphasis on its energy efficiency. The impact of different mobility patterns on existing DTN routing algorithms with respect to data dissemination and energy consumption has also not been studied so far. Our objective, in this paper, is to investigate the impact of different mobility patterns on existing DTN routing protocols and existing DTN architectures and subsequently, come up with a suitable energy efficient DTN framework combining suitable architecture and routing protocol that may be used to offer different disaster management services during post-disaster relief operation. We have done an extensive simulation on ONE simulator with different categories of well-known existing DTN architectures, mobility models, DTN routing protocols to study the network performance in terms of delivery probability, energy efficiency and overhead ratio. Based on the simulation results, we have tried to figure out a suitable combination of energy efficient architecture, mobility model and routing protocol that fits well in the post disaster communication scenario.

Validation of Fuzzy-Based Routing Algorithm for DTN

In the research of Delay Tolerant Network (DTN), DTN routing algorithm is a key research issue. The performance of a non-flooding routing algorithm is verified in our paper. The verified algorithm is an Adaptive Priority Routing Algorithm (APRA) which is based on fuzzy strategies. Firstly, we introduce the principle of APRA, then using Opportunistic Network Environment (ONE) -simulation software to compare the performance of Epidemic algorithm, Spray and Wait algorithm, PRoPHET algorithm and APRA. By comparing overhead of netword, rate of messages delivered and average dealy, it finds that the APRA performs better. At last, the weaknesses of this paper and further improvement are also discussed.

A New Optimization Strategy Proposal for Multi-Copy Forwarding in Energy Constrained DTNs

Most routing algorithms in delay tolerant networks (DTNs) have not taken adequately into account the issue of energy constraint for communication. In this paper, we propose a new optimization strategy for different DTN routing algorithms that use an utility function to select the best nodes to relay messages, but that were originally proposed without regard to the issue of energy. Our proposed optimization strategy is based on the modeling of multi-copy forwarding as a Bayesian signaling game. A system for belief update concerning the energy of the other DTN nodes based on the accumulated observations of the destination nodes is considered. Simulation results show that our proposed optimization strategy can maintain the network nodes operational for a longer period of time.

Performance analysis of hop‐limited epidemic routing in DTN with limited forwarding times

SummaryBecause of the uncertainty of transmission opportunity in delay tolerant networks (DTN), routing algorithms in DTN often need nodes to serve as relays for others to carry and forward messages. One classic policy is the Epidemic routing (ER) algorithm. To reduce the overhead, the hop‐limited ER protocol is proposed. This method can get better performance through controlling the message hop count. However, because of the energy constraint or other factors, each node may forward only limited times, that is, both the message hop count and the forwarding times may be limited. This paper proposes a unifying framework to evaluate the performance of ER with the aforementioned constraints. Simulations based on both synthetic and real motion traces show the accuracy of the framework. In addition, we explore the impact of many parameters (e.g., message hop count) through extensive numerical results. For example, numerical results show that both the message hop count and the forwarding times can have certain impact on the routing performance, but their impact is related with many other factors (e.g., the number of nodes). Copyright © 2014 John Wiley & Sons, Ltd.

주기적 이동 노드를 위한 Delay-Tolerant Network 라우팅 알고리즘

Delay-Tolerant Network (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 mobile ad-hoc network (MANET) as well as space communication that supports data transmissions among satellites. In DTN networking environments, it is very important to secure a scheme that has relatively low routing overhead and high reliability, so that it can enhance the overall routing speed and performance. In order for achieving efficient data transmissions among the nodes that have comparatively periodic moving patterns, this paper proposes a time information based DTN routing scheme which is able to predict routing paths. From the simulation results using Omnet++ simulation tools, it has been verified that the proposed time information based DTN routing algorithm shows satisfied levels of routing speed and routing reliability even with lower routing overheads.

A Survey of Social-Aware Routing Protocols in Delay Tolerant Networks: Applications, Taxonomy and Design-Related Issues

In the past few years, more and more researchers have paid close attention to the emerging field of delay tolerant networks (DTNs), in which network often partitions and end-to-end paths do not exist nearly all the time. To cope with these challenges, most routing protocols employ the store-carry-forward strategy to transmit messages. However, the difficulty of this strategy is how to choose the best relay node and determine the best time to forward messages. Fortunately, social relations among nodes can be used to address these problems. In this paper, we present a comprehensive survey of recent social-aware routing protocols, which offer an insight into how to utilize social relationships to design efficient and applicable routing algorithms in DTNs. First, we review the major practical applications of DTNs. Then, we focus on understanding social ties between nodes and investigating some design-related issues of social-based routing approaches, e.g., the ways to obtain social relations among nodes, the metrics and approaches to identify the characteristics of social ties, the strategies to optimize social-aware routing protocols, and the suitable mobility traces to evaluate these protocols. We also create a taxonomy for social-aware routing protocols according to the sources of social relations. Finally, we outline several open issues and research challenges.

A venues‐aware message routing scheme for delay‐tolerant networks

AbstractWith their proliferation and increasing capabilities, mobile devices with local wireless interfaces can be organized into delay‐tolerant networks (DTNs) that exploit communication opportunities arising out of the movement of their users. As the mobile devices are usually carried by people, these DTNs can also be viewed as social networks. Unfortunately, most existing routing algorithms for DTNs rely on relatively simple mobility models that rarely consider these social network characteristics, and therefore, the mobility models in these algorithms cannot accurately describe users’ real mobility traces. In this paper, we propose two predict and spread (PreS) message routing algorithms for DTNs. We employ an adapted Markov chain to model a node's mobility pattern and capture its social characteristics. A comparison with state‐of‐the‐art algorithms demonstrates that PreS can yield better performance in terms of delivery ratio and delivery latency, and it can provide a comparable performance with the epidemic routing algorithm with lower resource consumption. Copyright © 2013 John Wiley & Sons, Ltd.

The DTN Routing Algorithm Based on Markov Meeting Time Span Prediction Model

Putting forward an efficient routing algorithm in DTN (delay tolerant network) has become a focus of attention due to the existing phenomena that the connections between nodes in the network change dramatically over time and the communications suffer from frequent disruptions. In this paper, the meeting time span between nodes is predicted using the Markov model, and the relay node holding the shortest meeting time span with the destination node is determined as the most efficient node. In the two phases, spray phase and wait phase, the message is routed according to the utility value. Thus, the routing algorithm based on Markov meeting time span prediction model is provided. Simulation results suggest that this algorithm efficiently improves the delivery rate and reduces the average delay.

DAWN: A density adaptive routing for deadline-based data collection in vehicular delay tolerant networks

Vehicular Delay Tolerant Networks (DTN) use moving vehicles to sample and relay sensory data for urban areas, making it a promising low-cost solution for the urban sensing and infotainment applications. However, routing in the DTN in real vehicle fleet is a great challenge due to uneven and fluctuant node density caused by vehicle mobility patterns. Moreover, the high vehicle density in urban areas makes the wireless channel capacity an impactful factor to network performance. In this paper, we propose a local capacity constrained density adaptive routing algorithm for large scale vehicular DTN in urban areas which targets to increase the packet delivery ratio within deadline, namely Density Adaptive routing With Node deadline awareness (DAWN). DAWN enables the mobile nodes awareness of their neighbor density, to which the nodes' transmission manners are adapted so as to better utilize the limited capacity and increase the data delivery probability within delay constraint based only on local information. Through simulations on Manhattan Grid Mobility Model and the real GPS traces of 4960 taxi cabs for 30 days in the Beijing city, DAWN is demonstrated to outperform other classical DTN routing schemes in performance of delivery ratio and coverage within delay constraint. These simulations suggest that DAWN is practically useful for the vehicular DTN in urban areas.

Energy-efficient Joint Control of Epidemic Routing in Delay Tolerant Networks

Due to the uncertain of connections in Delay Tolerant Networks (DTNs), most routing algorithms in DTNs need nodes to forward the message to others based on the opportunistic contact. The contact is related with the beaconing rate. In particular, nodes have more chances to encounter with each other with bigger beaconing rate, but more energy will be used. On the other hand, if the nodes forward the message to every node all the time, the efficiency of the routing algorithm is better, but it needs more energy, too. This paper tries to exploit the optimal beaconing rate and forwarding rate when the total energy is constraint. First, a theoretical framework is proposed, which can be used to evaluate the performance with different forwarding rate and beaconing rate. Then, this paper formulates a joint optimization problem based on the framework. Through Pontryagin’s Maximal Principle, this paper obtains the optimal policy and proves that both the optimal forwarding and beaconing rates conform to threshold form. Simulation results show the accuracy of the theoretical framework. Extensive numerical results show that the optimal policy obtained in this paper is the best.

Preference Location-based Routing in Delay Tolerant Networks

Routing in Delay Tolerant Networks (DTNs) is a challenge due to the fact that the network graph is intermittently connected. However, routing benefits considerably if one can take advantage of knowledge concerning nodes mobility, recent studies have shown that human have location visiting preferences in their daily mobility traces, considering this is a common and stable property of human, we utilize it in the design of routing algorithm for social-oriented DTNs. In this paper, we propose a preference location-based routing strategy (PLBR). We focus on three aspects, according to the longterm behavior, we first provide the approach of acquiring one’s preference locations, then the closeness metric which is used to measure the degree of proximity of any two nodes is proposed, on the basis of that, the data forwarding algorithm is presented. Simulations based on real mobility traces show that compared to other two relevant routing protocols in DTNs, PLBR strategy achieves better tradeoff between the data delivery ratio/delay and the delivery overhead.

Spray and forward: Efficient routing based on the Markov location prediction model for DTNs

Typical delay tolerant networks (DTNs) often suffer from long and variable delays, frequent connectivity disruptions, and high bit error rates. In DTNs, the design of an efficient routing algorithm is one of the key issues. The existing methods improve the accessibility probability of the data transmission by transmitting many copies of the packet to the network, but they may cause a high network overhead. To address the tradeoff between a successful delivery ratio and the network overhead, we propose a DTN routing algorithm based on the Markov location prediction model, called the spray and forward routing algorithm (SFR). Based on historical information of the nodes, the algorithm uses the second-order Markov forecasting mechanism to predict the location of the destination node, and then forwards the data by greedy routing, which reduces the copies of packets by spraying the packets in a particular direction. In contrast to a fixed mode where a successful-delivery ratio and routing overhead are contradictory, a hybrid strategy with multi-copy forwarding is able to reduce the copies of the packets efficiently and at the same time maintain an acceptable successful-delivery ratio. The simulation results show that the proposed SFR is efficient enough to provide better network performance than the spray and wait routing algorithm, in scenarios with sparse node density and fast mobility of the nodes.

Evaluating the effects of node cooperation on DTN routing

Abstract Due to the uncertainty of transmission opportunities between mobile nodes, delay tolerant networks (DTN) routing exploits the opportunistic forwarding mechanism. This mechanism requires nodes to forward messages in a cooperative way. However, in the real word, most of the nodes exhibit non-cooperation behaviors such as dropping and not relaying messages. In this letter, we investigate the problem of how the non-cooperation behaviors of nodes influence the performance of DTN routing algorithms of two-hop relay and epidemic routing. First, we model the message delivery process with non-cooperation behaviors by a two dimensional continuous time Markov chain. Then, we obtain the system performance of message delivery delay and delivery cost by explicit expressions. Numerical results show that different non-cooperation behaviors may have opposite impacts on different routing algorithms. Specifically, dropping message increases the message delivery delay and delivery cost in the two-hop relay, while increases the delay but does not affect the delivery cost in the epidemic routing, and not relaying message increases the delivery delay but decreases the delivery cost for both the two-hop and epidemic routing.