In this paper, we address the problem of routing in delay tolerant networks (DTN). In such networks there is no guarantee of finding a complete communication path connecting the source and destination at any time, esp...In this paper, we address the problem of routing in delay tolerant networks (DTN). In such networks there is no guarantee of finding a complete communication path connecting the source and destination at any time, especially when the destination is not in the same region as the source, which makes traditional routing protocols inefficient in that transmission of the messages between nodes. We propose to combine the routing protocol MaxProp and the model of “transfer by delegation” (custody transfer) to improve the routing in DTN networks and to exploit nodes as common carriers of messages between the network partitioned. To implement this approach and assess those improvements and changes we developed a DTN simulator. Simulation examples are illustrated in the article.展开更多
Satellite networks have many inherent advantages over terrestrial networks and have become an important part of the global network infrastructure.Routing aimed at satellite networks has become a hot and challenging re...Satellite networks have many inherent advantages over terrestrial networks and have become an important part of the global network infrastructure.Routing aimed at satellite networks has become a hot and challenging research topic.Satellite networks,which are special kind of Delay Tolerant Networks(DTN),can also adopt the routing solutions of DTN.Among the many routing proposals,Contact Graph Routing(CGR) is an excellent candidate,since it is designed particularly for use in highly deterministic space networks.The applicability of CGR in satellite networks is evaluated by utilizing the space oriented DTN gateway model based on OPNET(Optimized Network Engineering Tool).Link failures are solved with neighbor discovery mechanism and route recomputation.Earth observation scenario is used in the simulations to investigate CGR's performance.The results show that the CGR performances are better in terms of effectively utilizing satellite networks resources to calculate continuous route path and alternative route can be successfully calculated under link failures by utilizing fault tolerance scheme.展开更多
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) ...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 meanfield 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.展开更多
This paper addresses the problem of routing in delay tolerant networks (DTNs). Delay tolerant networks are wireless networks where disconnections occur frequently due to mobility of nodes, failures of energy, the low ...This paper addresses the problem of routing in delay tolerant networks (DTNs). Delay tolerant networks are wireless networks where disconnections occur frequently due to mobility of nodes, failures of energy, the low density of nodes, or when the network extends over long distances. In these cases, traditional routing protocols that have been developed for mobile ad hoc networks prove to be ineffective to the extent of transmitting messages between nodes. To resolve this problem and improve the performance of routing in delay tolerant networks we propose a new routing protocol called Spray and Dynamic;this approach represents an improvement of the spray and wait protocol by combining it with the two protocols: MaxProp and the model of “transfer by delegation” (Custody Transfer). To implement our approach Spray and Dynamic, we have developed a DTN simulator according to DTN network architecture.展开更多
This paper investigates the maximum network through- put for resource-constrained space networks based on the delay and disruption-tolerant networking （DTN） architecture. Specifically, this paper proposes a methodol...This paper investigates the maximum network through- put for resource-constrained space networks based on the delay and disruption-tolerant networking （DTN） architecture. Specifically, this paper proposes a methodology for calculating the maximum network throughput of multiple transmission tasks under storage and delay constraints over a space network. A mixed-integer linear programming （MILP） is formulated to solve this problem. Simula- tions results show that the proposed methodology can successfully calculate the optimal throughput of a space network under storage and delay constraints, as well as a clear, monotonic relationship between end-to-end delay and the maximum network throughput under storage constraints. At the same time, the optimization re- sults shine light on the routing and transport protocol design in space communication, which can be used to obtain the optimal network throughput.展开更多
文摘In this paper, we address the problem of routing in delay tolerant networks (DTN). In such networks there is no guarantee of finding a complete communication path connecting the source and destination at any time, especially when the destination is not in the same region as the source, which makes traditional routing protocols inefficient in that transmission of the messages between nodes. We propose to combine the routing protocol MaxProp and the model of “transfer by delegation” (custody transfer) to improve the routing in DTN networks and to exploit nodes as common carriers of messages between the network partitioned. To implement this approach and assess those improvements and changes we developed a DTN simulator. Simulation examples are illustrated in the article.
基金Supported by the open project of Communication network transmission and distribution technologies Key Laboratory(ITD-12005/K1260011)the National Natural Science Foundation of China(61371126) and the National Natural Science Foundation of China(60903195)
文摘Satellite networks have many inherent advantages over terrestrial networks and have become an important part of the global network infrastructure.Routing aimed at satellite networks has become a hot and challenging research topic.Satellite networks,which are special kind of Delay Tolerant Networks(DTN),can also adopt the routing solutions of DTN.Among the many routing proposals,Contact Graph Routing(CGR) is an excellent candidate,since it is designed particularly for use in highly deterministic space networks.The applicability of CGR in satellite networks is evaluated by utilizing the space oriented DTN gateway model based on OPNET(Optimized Network Engineering Tool).Link failures are solved with neighbor discovery mechanism and route recomputation.Earth observation scenario is used in the simulations to investigate CGR's performance.The results show that the CGR performances are better in terms of effectively utilizing satellite networks resources to calculate continuous route path and alternative route can be successfully calculated under link failures by utilizing fault tolerance scheme.
基金supported by the National Nature Science Foundation of China(61871388)
文摘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 meanfield 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.
文摘This paper addresses the problem of routing in delay tolerant networks (DTNs). Delay tolerant networks are wireless networks where disconnections occur frequently due to mobility of nodes, failures of energy, the low density of nodes, or when the network extends over long distances. In these cases, traditional routing protocols that have been developed for mobile ad hoc networks prove to be ineffective to the extent of transmitting messages between nodes. To resolve this problem and improve the performance of routing in delay tolerant networks we propose a new routing protocol called Spray and Dynamic;this approach represents an improvement of the spray and wait protocol by combining it with the two protocols: MaxProp and the model of “transfer by delegation” (Custody Transfer). To implement our approach Spray and Dynamic, we have developed a DTN simulator according to DTN network architecture.
基金supported by the National Natural Sciences Foundation of China(6113200261321061+3 种基金6123101161201183)the National Basic Research Program of China(2014CB340206)the Tsinghua University Initiative Scientific Research Program(2011Z05117)
文摘This paper investigates the maximum network through- put for resource-constrained space networks based on the delay and disruption-tolerant networking （DTN） architecture. Specifically, this paper proposes a methodology for calculating the maximum network throughput of multiple transmission tasks under storage and delay constraints over a space network. A mixed-integer linear programming （MILP） is formulated to solve this problem. Simula- tions results show that the proposed methodology can successfully calculate the optimal throughput of a space network under storage and delay constraints, as well as a clear, monotonic relationship between end-to-end delay and the maximum network throughput under storage constraints. At the same time, the optimization re- sults shine light on the routing and transport protocol design in space communication, which can be used to obtain the optimal network throughput.
