HUBCODE: hub‐based forwarding using network coding in delay tolerant networks

Abstract

Most people-centric delay tolerant networks have been shown to exhibit power-law behavior. Analysis of the temporal connectivity graph of such networks reveals the existence of hubs, a fraction of the nodes, which are collectively connected to the rest of the nodes. In this paper, we propose a novel forwarding strategy called HubCode, which seeks to use the hubs as message relays. The hubs employ random linear network coding to encode multiple messages addressed to the same destination, thus reducing the forwarding overheads. Further, the use of the hubs as relays ensures that most messages are delivered to the destinations. Two versions of HubCode are presented, with each scheme exhibiting contrasting behavior in terms of the computational costs and routing overheads. We formulate a mathematical model for message delivery delay and present a closed-form expression for the same. We validate our model and demonstrate the efficacy of our solutions in comparison with other forwarding schemes by simulating a large-scale vehicular delay tolerant network using empirically collected movement traces of a city-wide public transport network. Under pragmatic assumptions, which account for short contact durations between nodes, our schemes outperform comparable strategies by more than 20%.

Opportunistic message routing using multi-layer social networks

“…Messages are then forwarded to the node holding the highest overall utility for the message destination node. In [1] and [23], the popularity of a node in DSN is exploited for message forwarding. In the former, popular nodes (called hubs) are those connected with most of the other nodes in DSN and are characterized by analyzing the history of encounters.…”

“…Commonly, the social information is extracted from encounters between mobile devices detected through wireless interfaces such as Bluetooth, ZigBee and Wi-Fi [11,14,5,1,23,6]. However, other social interaction techniques that are not based on physical meetings provide us with insights into user behavior such as email, chats and online social networks services (e.g.…”

Flexible and dynamic network coding for adaptive data transmission in DTNs

“…State of the art routing approaches exploit the power-law behaviour that these networks exhibit (i.e. existence of more centralised nodes that can collectively connect to the rest of the nodes [1]) and use highly central nodes as message relays that employ random linear coding addressed to the same destination [2]. At times of increasing traffic demands, the highly central nodes and parts of the network can get congested.…”

Secure Network Coding in DTNs

“…Several research results show the benefit of coding in this environment [1]- [5], however all of them operates in benign environment. If we take into account that an adversarial node can launch pollution attack, the performance of the system seriously drops [6], [7].…”

“…In this letter we do not make any further assumptions on the message encoding and forwarding algorithm. For particular protocols we refer the reader to [1]- [3].…”