Avaliando Contatos em Redes Oportunistas

• André B. Oliveira UFMG
• Diego N. da Hora UFMG
• Virgil del Duca Almeida UFMG
• Daniel F. Macedo UFMG

Abstract

Opportunistic Networks (ONs) are mobile networks that support intermittent links and long delays. ON nodes exchange data in brief moments called contacts, when another node is within radio range. Contacts are ephemeral and unpredictable, thus they must be implemented as efficiently as possible. Further, most previous work rely on simplistic assumptions such as unlimited bandwidth and contention-free transmissions. This paper presents a more realistic evaluation of ON contacts. Simulations show that, on opposition to the consensus in the literature, routing protocols that forward more copies and those that determine a subset of nodes to receive the Bundles using a certain criteria outperform flooding-based protocols, because the latter generates too much medium contention. Finally, buffer management and forwarding prioritization may influence the performance of the network by up to 30%.

References

Boudec, J.-Y. L. and Vojnovic, M. (2006). The random trip model: stability, stationary regime, and perfect simulation. IEEE/ACM Trans. Netw., 16(6):1153–1166.

Cao, Y. and Sun, Z. (2012). Routing in delay/disruption tolerant networks: A taxonomy, survey and challenges. IEEE Communications Surveys & Tutorials, 8(1):1 –24.

Cerf, V., Burleigh, S., Hooke, A., Torgerson, L., Durst, R., Scott, K., Fall, K., and Weiss, H. (2007). Delay-Tolerant Networking Architecture. RFC 4838 (Informational).

Chaintreau, A., Hui, P., Crowcroft, J., Diot, C., Gass, R., and Scott, J. (2007). Impact of human mobility on opportunistic forwarding algorithms. IEEE Trans. Mob. Comput., 6(6):606–620.

Cisco (2012). Cisco Aironet 350 series client adapters. [link].

Fall, K. (2003). A delay-tolerant network architecture for challenged internets. In Proceedings of SIGCOMM.

Keränen, A., Ott, J., and Kärkkäinen, T. (2009). The ONE Simulator for DTN Protocol Evaluation. In Proceedings of the 2nd International Conference on Simulation Tools and Techniques (SIMUTools).

Lindgren, A. and Phanse, K. (2006). Evaluation of queueing policies and forwarding strategies for routing in intermittently connected networks. In International Conference on Communication System Software and Middleware (Comsware), pages 1–10.

Manfredi, V., Crovella, M., and Kurose, J. (2011). Understanding stateful vs stateless In Proceedings of the international communication strategies for ad hoc networks. conference on mobile computing and networking (MobiCom), pages 313–324.

Network Simulator (Dez., 2012). NS-2 simulator. http://www.isi.edu/nsnam/ns/.

Pelusi, L., Passarella, A., and Conti, M. (2006). Opportunistic networking: data forwarding in disconnected mobile ad hoc networks. Communications Magazine, IEEE, 44(11):134–141.

Ristanovic, N., Theodorakopoulos, G., and Le Boudec, J. (2012). Traps and pitfalls of using contact traces in performance studies of opportunistic networks. In IEEE Infocom, pages 1377–1385.

Tournoux, P. U., Leguay, J., Benbadis, F., Conan, V., de Amorim, M. D., and Whitbeck, J. (2009). The Accordion Phenomenon: Analysis, Characterization, and Impact on DTN Routing. In IEEE INFOCOM 2009, pages 1116–1124.

Whitehouse, K., Woo, A., Jiang, F., Polastre, J., and Culler, D. (2005). Exploiting the capture effect for collision detection and recovery. In Proceedings of the IEEE workshop on embedded networked sensors (EmNetS-II), pages 45–52.