256 research outputs found
SocialDTN: A DTN implementation for Digital and Social Inclusion
Despite of the importance of access to computers and to the Internet for the
development of people and their inclusion in society, there are people that
still suffer with digital divide and social exclusion.
Delay/Disruption-Tolerant Networking (DTN) can help the digital/social
inclusion of these people as it allows opportunistic and asynchronous
communication, which does not depend upon networking infrastructure. We
introduce SocialDTN, an implementation of the DTN architecture for Android
devices that operates over Bluetooth, taking advantages of the social daily
routines of users. As we want to exploit the social proximity and interactions
existing among users, SocialDTN includes a social-aware opportunistic routing
proposal, dLife, instead of the well-known (but social-oblivious) PROPHET.
Simulations show the potential of dLife for our needs. Additionally, some
preliminary results from field experimentations are presented.Comment: 3 pages, 4 figure
VECTORS: Video communication through opportunistic relays and scalable video coding
Crowd-sourced video distribution is frequently of interest in the local
vicinity. In this paper, we propose a novel design to transfer such content
over opportunistic networks with adaptive quality encoding to achieve
reasonable delay bounds. The video segments are transmitted between source and
destination in a delay tolerant manner using the Nearby Connections Android
library. This implementation can be applied to multiple domains, including farm
monitoring, wildlife, and environmental tracking, disaster response scenarios,
etc. In this work, we present the design of an opportunistic contact based
system, and we discuss basic results for the trial runs within our institute.Comment: 13 pages, 6 figures, and under 3000 words for submission to the
SoftwareX journa
DIP: Disruption-Tolerance for IP
Disruption Tolerant Networks (DTN) have been a popular subject of recent
research and development. These networks are characterized by frequent, lengthy
outages and a lack of contemporaneous end-to-end paths. In this work we discuss
techniques for extending IP to operate more effectively in DTN scenarios. Our
scheme, Disruption Tolerant IP (DIP) uses existing IP packet headers, uses the
existing socket API for applications, is compatible with IPsec, and uses
familiar Policy-Based Routing techniques for network management
Routing in a many-to-one communication scenario in a realistic VDTN
In this paper, we evaluate and compare the performance of different routing protocols in a many-to-one communication within a Vehicular Delay Tolerant Network (VDTN). Seven groups with three stationary sensor nodes sense the temperature, humidity and wind speed and send these data to a stationary destination node that collect them for statistical and data analysis purposes. Vehicles moving in Tirana city roads in Albania during the opportunistic contacts will exchange the sensed data to destination node. The simulations are conducted with the Opportunistic Network Environment (ONE) simulator. For the simulations we considered two different scenarios where the distance of the source nodes from the destination is short and long. For both scenarios the effect of node density, ttl and node movement model is evaluated. The performance is analyzed using delivery probability, overhead ratio, average latency, average number of hops and average buffer time metrics. The simulation results show that the increase of node density increases the delivery probability for all protocols and both scenarios, and better results are achieved when shortest-path map-based movement model is used. The increase of ttl slightly affects the performance of all protocols. By increasing the distance between source nodes and destination node, delivery probability is decreased almost 10% for all protocols, the overhead for sprayandwait protocol does not change, but for other protocols is slightly increased and the average number of hops and average latency is increased.Peer ReviewedPostprint (author's final draft
A mobile agent and message ferry mechanism based routing for delay tolerant network
Delay Tolerant Network (DTN) is a class of networks characterized by long delays, frequent disconnections and partitioning of communication paths between network nodes. Due to the frequent disconnection and network partitioning, the overall performance of the network will be deteriorated sharply. The problem is how to make the network fairly connected to optimize data routing and enhance the performance of a network. The aim of this study is to improve the performance of DTN by minimizing end-to-end delivery time and increasing message delivery ratio. Therefore, this research tackles the problem of intermittent connectivity and network partitioning by introducing Agents and Ferry Mechanism based Routing (AFMR). The AFMR comprises of two stages by applying two schemes: mobile agents and ferry mechanism. The agents' scheme is proposed to deal with intermittent connectivity and network partitioning by collecting the basic information about network connection such as signal strength, nodes position in the network and distance to the destination nodes to minimize end-to-end delivery time. The second stage is to increase the message delivery ratio by moving the nodes towards the path with available network connectivity based on agents' feedback. The AFMR is evaluated through simulations and the results are compared with those of Epidemic, PRoPHET and Message Ferry (MF). The findings demonstrate that AFMR is superior to all three, with respect to the average end-to-end delivery time, message delivery ratio, network load and message drop ratio, which are regarded as extremely important metrics for the evaluation of DTN routing protocols. The AFMR achieves improved network performance in terms of end-to-end delivery time (56.3%); enhanced message delivery ratio (60.0%); mitigation of message drop (63.5%) and reduced network load (26.1 %). The contributions of this thesis are to enhance the performance of DTN by significantly overcoming the intermittent connectivity and network partitioning problems in the network
The fans united will always be connected: building a practical DTN in a football stadium
Football stadia present a difficult environment for the deployment of digital services, due to their architectural design and the capacity problems from the numbers of fans. We present preliminary results from deploying an Android app building an ad hoc network amongst the attendees at matches at Brighton and Hove Albion's AMEX stadium, so as to share the available capacity and supply digital services to season
ticket holders. We describe the protocol, how we engaged our users in service design so that the app was attractive to use and the problems we encountered in using Android
Marine Delay and Disruption Tolerant Networks (MaDTN): Application for Artisanal Fisheries
The artisanal fishing activity carried out on the coasts where the production of fish can be exploited is affected by a lack of communication between the vessels in order to provide relevant information related to multiple marine sensor parameters. It is mainly due to the rugged geographic area that causes highly disruptive communication links and in which traditional IP-based communications with transport protocols such as TCP or UDP do not work properly. This paper presents and evaluates a new communications architecture to provide services to marine sensor networks using a disruption tolerant networking (DTN) based solution. We propose a new architecture that takes into account the different vessels densities. We assume a finite sensor population model and a saturated traffic condition where every sensor always has frames to transmit. The performance was evaluated in terms of delivery probabilities, delay and a DTN scenario indicator (DSI) proposed. Through simulations, this paper reveals that Low Density scenery yield greater latency, and more density of nodes has better results. We achieved a successful delivery rate of 74% and a latency of 2 h approximately. Finally indicators shows that high density of nodes is strongly recommended for fishery scenery models
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