Mikko Juhani Pitkänen

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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)
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)
Delay-tolerant networking is used for communication in challenged environments such as MANETs, in which links are unstable and end-to-end paths between communicating nodes may not exist. Messages may be significantly larger than packets in IP networks. Large messages lead to longer transfer times rendering it more likely that a link breaks in the middle of(More)
Delay-tolerant networking (DTN) enables nodes to communicate by means of asynchronous messaging witout the need for an end-to-end path. Suitably designed application protocols may operate in DTNs by minimizing end-to-end interactions and using self-contained messages for communication. The store-carry-and-forward operation and message replication of many(More)
In this paper, we study how to adapt the routing according to dynamic network conditions in wireless ad hoc networks. We present a method that dynamically chooses routing agent between ad hoc on-demand distance vector routing protocol (AODV) with TCP (end-to-end transport) and delay-tolerant networking (DTN) routing and bundle protocol (hop-by-hop(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)
Today's medical institutions produce enormous amounts of data on patients, including multimedia data, which is increasingly produced in digital form. These data in their clinical context contain much information and experience that is currently not being used up to its full potential. Through the digital form the data has become accessible for automatic(More)
When applying delay-tolerant networking concepts to communication in mobile ad-hoc networks formed between mobile users, a general assumption is that users are willing to share own resources to support communication between others. However, we cannot assume that all users are altruistic in their behavior; instead, we have to deal with users who only make a(More)
Opportunistic networking between mobile devices relies on the capabilities of those devices to establish ad-hoc communication among each other. While the two dominant wireless interface technologies, IEEE 802.11 wireless LAN and Bluetooth, offer such capabilities in theory, limitations of the protocol specification, chipsets, and operating systems in mobile(More)