A Reliable and Efficient Encounter-Based Routing Framework for Delay/Disruption Tolerant Networks

This article addresses Delay/Disruption Tolerant Networking (DTN) routing under a highly dynamic scenario, envisioned for communication in Vehicular Sensor Networks (VSNs) suffering from intermittent connection. Here, we focus on the design of a high level routing framework, rather than the dedicated encounter prediction. Based on an analyzed utility metric to predict nodal encounter, our proposed routing framework considers the following three cases: 1) Messages are efficiently replicated to a better qualified candidate node, based on the analysed utility metric related to destination. 2) Messages are conditionally replicated if the node with a better utility metric has not been met. 3) Messages are probabilistically replicated if the information in relation to destination is unavailable in the worst case. With this framework in mind, we propose two routing schemes covering two major technique branches in literature, namely Encounter-Based Replication Routing (EBRR) and Encounter-Based Spraying Routing (EBSR). Results under the scenario applicable to VSNs show that, in addition to achieving high delivery ratio for reliability, our schemes are more efficient in terms of a lower overhead ratio. Our core investigation indicates that apart from what information to use for encounter prediction, how to deliver messages based on the given utility metric is also important

Flows and Frictions in Trans-Himalayan Spaces

Flows and Frictions in Trans-Himalayan Spaces traces movements and connections in a region known for its formidable obstacles to mobility. Eight original essays and a conceptual introduction engage with questions of networks and interconnection between people across a bordered landscape. Mobility among the extremely varied ecologies of south-western China, Myanmar and north-eastern India, with their rugged terrain, high mountains, monsoon-fed rivers and marshy lowlands, is certainly subject to friction. But today, harsh political realities have created hard borders and fractured this trans-Himalayan terrain. However, the closely researched chapters in this book demonstrate that these borders have not prevented an abundance of movements, connections and flows. Mobility has always coexisted with friction here, but this coexistence has been unsettled, giving this space its historical shape and its contemporary dynamism. Introducing the concept of the ‘corridor’ as an analytical framework, this collection investigates mobility and flows in this unique socio-political landscape