Teemu Kärkkäinen

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Delay-tolerant Networking (DTN) enables communication in sparse mobile ad-hoc networks and other challenged environments where traditional networking fails and new routing and application protocols are required. Past experience with DTN routing and application protocols has shown that their performance is highly dependent on the underlying mobility and node(More)
Delay-tolerant Networking (DTN) enables communication in sparse mobile ad-hoc networks and other challenged environments where traditional networking fails and new routing and application protocols are required. Past experience with DTN routing and application protocols has shown that their performance is highly dependent on the underlying mobility and node(More)
Allowing mobile users to find and access resources available in the surrounding environment opportunistically via their smart devices could enable them to create and use a rich set of services. Such services can go well beyond what is possible for a mobile phone acting alone. In essense, access to diverse resources such as raw computational power, social(More)
The communication paradigms for delay-tolerant networking have been modeled after email. Supporting email over DTNs in a backwards compatible manner in a heterogeneous environment has yet to be fully defined. In this paper, we present a set of conventions for and extensions to the DTNRG architecture. We have implemented a system that is able to deliver(More)
Delay-tolerant Networking (DTN) provides a platform for applications in environments where end-to-end paths may be highly unreliable or do not exist at all. In many applications such as distributed wikis or photo sharing, users need to be able to find content even when they do not know an unambiguous identifier. In order do bring these applications to the(More)
Past research on opportunistic communications has demonstrated the power of mobile phones as information mediators and content providers to co-located devices. As an extension of opportunistic communication paradigm, opportunistic computing and services research leverages the powerful capabilities and pervasive nature of modern smartphones to provision(More)
Physical movement of people and equipment in a mine is largely predictable and periodic. Therefore, the data communication system for managing the equipment fleet in a mine could be based on intermediate nodes (trucks, people’s phones, and other mobile devices) that physically carry data messages between an operator console and distant mining equipment. We(More)
Mobile phones are becoming commonplace for consuming Internet content and services. However, availability, affordability, and quality of the supposedly ubiquitous cellular network infrastructure may be limited, so that delay-tolerant web access via WLAN hotspots becomes an interesting alternative, even in urban areas. In this paper we explore mobile web(More)
We present the Liberouter framework, a complete communication system design (and its implementation) to enable neighborhood networking without relying on the Internet infrastructure for information exchange. The core is a low-cost router platform that serves as WLAN access points, individual or (dis)connected ones, and offers message storage and relaying in(More)