Optimal Forwarding in Delay-Tolerant Networks With Multiple Destinations

Singh, Chandramani and Altman, Eitan and Kumar, Anurag and Sundaresan, Rajesh (2013) Optimal Forwarding in Delay-Tolerant Networks With Multiple Destinations. In: IEEE-ACM TRANSACTIONS ON NETWORKING, 21 (6). pp. 1812-1826.

PDF IEEE_ACM_TRA_Net_21-6_1812_2013.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

We study the tradeoff between delivery delay and energy consumption in a delay-tolerant network in which a message (or a file) has to be delivered to each of several destinations by epidemic relaying. In addition to the destinations, there are several other nodes in the network that can assist in relaying the message. We first assume that, at every instant, all the nodes know the number of relays carrying the message and the number of destinations that have received the message. We formulate the problem as a controlled continuous-time Markov chain and derive the optimal closed-loop control (i.e., forwarding policy). However, in practice, the intermittent connectivity in the network implies that the nodes may not have the required perfect knowledge of the system state. To address this issue, we obtain an ordinary differential equation (ODE) (i.e., a deterministic fluid) approximation for the optimally controlled Markov chain. This fluid approximation also yields an asymptotically optimal open-loop policy. Finally, we evaluate the performance of the deterministic policy over finite networks. Numerical results show that this policy performs close to the optimal closed-loop policy.

Item Type:	Journal Article
Publication:	IEEE-ACM TRANSACTIONS ON NETWORKING
Publisher:	IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Additional Information:	Copyright for this article belongs to the IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, USA
Keywords:	Delay-tolerant networks (DTNs); epidemic relaying; fluid approximation; optimal control
Department/Centre:	Division of Electrical Sciences > Electrical Communication Engineering
Date Deposited:	21 Feb 2014 10:51
Last Modified:	21 Feb 2014 10:51
URI:	http://eprints.iisc.ac.in/id/eprint/48432

Actions (login required)

View Item