[Paper Review] Urban Delay Tolerant Network Simulator (UDTNSim v0.1)

Sarath Babu, Gaurav Jain+1 more|arXiv (Cornell University)|Sep 17, 2017

Opportunistic and Delay-Tolerant Networks3 citations

TL;DR

UDTNSim v0.1 is an open-source, object-oriented simulator for urban delay tolerant networks (DTNs), enabling simulation of mobility models and DTN routing protocols in realistic urban road environments. It supports six mobility models and three routing protocols, with a modular architecture for extensibility and a GUI for visual simulation, achieving up to 90% delivery ratio when map information is available.

ABSTRACT

Delay Tolerant Networking (DTN) is an approach to networking which handles network disruptions and high delays that may occur in many kinds of communication networks. The major reasons for high delay include partial connectivity of networks as can be seen in many types of ad hoc wireless networks with frequent network partitions, long propagation time as experienced in inter-planetary and deep space networks, and frequent link disruptions due to the mobility of nodes as observed in terrestrial wireless network environments. Experimenting network architectures, protocols, and mobility models in such real-world scenarios is difficult due to the complexities involved in the network environment. Therefore, in this document, we present the documentation of an Urban Delay Tolerant Network Simulator (UDTNSim) version 0.1, capable of simulating urban road network environments with DTN characteristics including mobility models and routing protocols. The mobility models included in this version of UDTNSim are (i) Stationary Movement, (ii) Simple Random Movement, (iii) Path Type Based Movememt, (iv) Path Memory Based Movement, (v) Path Type with Restricted Movement, and (vi) Path Type with Wait Movement. In addition to mobility models, we also provide three routing and data hand-off protocols: (i) Epidemic Routing, (ii) Superior Only Handoff, and (iii) Superior Peer Handoff. UDTNSim v0.1 is designed using object-oriented programming approach in order to provide flexibility in addition of new features to the DTN environment. UDTNSim v0.1 is distributed as an open source simulator for the use of the research community.

Motivation & Objective

• To address the challenge of simulating delay-tolerant networks in urban environments with high mobility and intermittent connectivity.
• To provide a flexible, open-source simulation framework for testing new mobility models and DTN routing protocols.
• To enable visual and quantitative evaluation of data delivery performance in urban road networks.
• To support research in emergency response systems using mobile agents and sensor data collection.

Proposed method

• The simulator uses an object-oriented architecture to modularize components such as mobility models, routing protocols, event handling, and GUI.
• It supports six mobility models: Stationary, Simple Random, Path Type Based, Path Memory Based, Path Type with Restricted Movement, and Path Type with Wait Movement.
• Three routing protocols are implemented: Epidemic Routing, Superior Only Handoff, and Superior Peer Handoff, using a store-and-forward approach with bundle layer semantics.
• The simulator uses XML-based configuration for simulation parameters and includes a parser for dynamic parameter loading.
• A graphical user interface (GUI) visualizes the road network, mobile nodes, and simulation events, with real-time reporting capabilities.
• The system employs a shared parameters object (global_params) to centralize simulation configuration and event management.

Experimental results

Research questions

• RQ1 How do different mobility models affect data delivery performance in urban DTNs with intermittent connectivity?
• RQ2 What is the impact of map information availability on delivery ratio in mobile data collection scenarios?
• RQ3 How do routing protocols like Epidemic, Superior Only Handoff, and Superior Peer Handoff compare in terms of delivery ratio and overhead?
• RQ4 To what extent can a simulator with realistic urban road networks and mobility patterns improve the evaluation of DTN protocols?
• RQ5 How effective are path-rescheduling models like Minimum Deviated Walk and Ortho Walk in emergency response scenarios?

Key findings

• When map information is available, mobility models such as Minimum Deviated Walk (MW) and Ortho Walk (OW) achieve over 90% delivery ratio, significantly outperforming models without map data.
• Without prior map information, the delivery ratio drops to only 20% using Path Type Based and Path Memory Based mobility models.
• The simulator's modular, object-oriented design enables efficient extension and integration of new mobility models and routing protocols.
• The GUI and reporting modules provide real-time visualization and detailed logs for simulation analysis and debugging.
• The use of a shared parameters object and XML-based configuration enhances configurability and maintainability of the simulation environment.
• The simulator supports realistic urban road network simulations with differentiated road types and agent-based mobility, enabling evaluation of emergency response systems.