Messages In Delay Tolerant Networks Research Articles

Using Hierarchical Community Structure to Improve Community-Based Message Routing

Information about community structure can be useful in a variety of mobile web applications. For instance, it has been shown that community-based methods can be more effective than alternatives for routing messages in delay-tolerant networks. In this paper we present initial research that shows that information on hierarchical structures in communities can further improve the effectiveness of message routing. This is interesting because despite much previous work on the topic, there have been few concrete applications which exploit hierarchical community structure.

An Efficient Delay Tolerant Networks Routing Protocol for Information-Centric Networking

Delay tolerant networks (DTN) is a good candidate for delivering information-centric networking (ICN) messages in fragmented networks due to disaster. In order to efficiently deliver ICN messages in DTN, the characteristics of multiple requester nodes for the same content and multiple provider nodes for the same request should be used efficiently. In this paper, we propose an efficient DTN routing protocol for ICN. In the proposed protocol, requester information for request packet, which is called an Interest in ICN, is shared by exchanging status table with requested Data ID, requester ID, and satisfaction flag, where satisfaction flag is defined to show the delivery status of Data, so that unnecessary forwarding of Data is avoided. Data is forwarded to a more probable node by comparing average delivery predictability to a set of requesters. Performance of the proposed protocol was evaluated using simulation from the aspect of Data delivery probability and Data overhead, for varying buffer sizes, number of relay nodes, and time-to-live (TTL) of Data. The results show that the proposed protocol has better Data delivery probability, compared to content distribution and retrieval framework in disaster networks for public protection (CIDOR) and opportunistic forwarding (OF) protocols, although there is a tradeoff from the aspect of Data overhead for varying buffer sizes and number of relay nodes.

Evolutionary forwarding games in delay tolerant networks: Equilibria, mechanism design and stochastic approximation

In this paper, we apply evolutionary games to non-cooperative forwarding control in Delay Tolerant Networks (DTNs). The main focus is on mechanisms to rule the participation of the relays to the delivery of messages in DTNs. Thus, we express the success probability as a function of the competition that takes place within a large population of mobiles, and we characterize the effect of reward-based mechanisms on the performance of such systems. Devices acting as active relays, in fact, sacrifice part of their batteries in order to support message replication and thus increase the probability to reach the destination. In our scheme, a relay can choose the strategy by which they participate to the message relaying. A mobile that participates receives a unit of reward based on the reward mechanism selected by the network. A utility function is introduced as the difference between the expected reward and the energy cost, i.e., the cost spent by the relay to sustain forwarding operations. We show how the evolution dynamics and the equilibrium behavior (called Evolutionary Stable Strategy – ESS) are influenced by the characteristics of inter contact time, energy expenditure and pricing characteristics.We extend our analysis to mechanisms that the system can introduce in order to have the message delivered to the destination with high probability within a given deadline and under energy constraints which bound the number of released copies per message. Finally, we apply our findings in order to devise decentralized forwarding algorithms that are rooted in the theory of stochastic approximations. Thus, we demonstrate that the ESS can be attained without complete knowledge of the system state and letting the source monitor number of released copies per message only. We provide extensive numerical results to validate the proposed scheme.

Traffic management strategy for delay-tolerant networks

Messages in delay-tolerant networks (DTNs) are generally classified by relative priority into low, medium, and high priority classes, thus creating challenges in structuring scheduling and drop policies of a traffic management system. This study proposes a novel traffic management strategy for DTNs. The proposed scheme improves message deliveries of different priority classes by utilizing message properties such as estimated total number of replicas, elapsed time, and remaining time-to-live. A delete mechanism of delivered messages is also incorporated to use buffer space efficiently. The performance of the proposed strategy is verified via implementation of a simulation model along with existing scheduling and drop policies and is tested with two well-known real-world trace datasets. The results demonstrate that the proposed strategy yields improved message deliveries of high priority as well as medium and low priority classes.

Comparison of Policies for Epidemic Broadcast in DTNs under Different Mobility Models

The broadcast diffusion of messages in Delay Tolerant Networks (DTNs) is heavily dependent on nodes mobility, since protocols must rely on contact opportunities among devices to diffuse data. This work is a first effort to study how the dynamics of nodes affect both the effectiveness of the broadcast protocols in diffusing data, and their efficiency in using the network resources. The paper describes three control mechanisms. The mechanisms characterize a family of protocols able to achieve some awareness about the surrounding environment, and to use this knowledge in order to keep the broadcast overhead low, while ensuring high node coverage. Simulation results identify the winning mechanisms to diffuse messages in DTNs under different conditions.

Agent Aided Routing for Faster and Efficient Spreading of Messages in Delay Tolerant Networks

Routing schemes in Delay Tolerant Networks depend on the intermediate nodes to carry messages till the forwarding of the messages to other nodes or delivery of the messages to their destinations. Thus, efficient and faster spreading of messages is essential to reduce the delay of sending a message from source to destination. In this work, we aim to design a new agent aided routing scheme in Delay Tolerant Networks to avoid large message delivery delay. Here, the source of a message is permitted to create unlimited copies of a message and distribute these copies to agents. Agents acting as the representative of the sources receive messages from the sources based on their node visited list and delivery predictability. After that, the agents forward the copies to the other intermediate nodes or deliver the message directly to the destination. Thus, the agents help in faster and efficient dissemination of a message in the network which helps in reducing message delivery delay. Besides, we compare our scheme with that of other schemes in different network scenarios through simulations. Simulation results show that our agent based routing scheme performs better than that of others in terms of Delivery Ratio, Delay and Communication Overhead.