Overview of the Science & Technology results/foregrounds of N4C

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The central idea of N4C has been to drive the evolving Delay and Disruption Tolerant Networking technology (DTN) towards practical usage. The strategy has been to combine this emerging future internet protocol set with data mules and wireless off-the shelf technology as carriers, including upgrading of WiMAX solutions for challenging scenarios. The relation to real use situations is typical for N4C. Nevertheless, to understand the project correctly, it is important that the majority of efforts have been spent with typical routines of technical research and development. The technical challenges have been notable and, the efforts needed to meet these challenges successfully have been considerable. For instance, the N4C DTN architecture idea, to use freely mobile nodes for the propagation of network traffic in remote and sparsely populated areas, was originally developed as a concrete response to a request from semi nomadic reindeer herders in Northern Scandinavia, for access to Information and Communications Technology (ICT). Clearly, network routing where there is no end-to-end connectivity is a challenge and, strategic issues as how to arrange network naming and addressing in such conditions affect how basic services such as e-mail can be supported.

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Having reached to the point, where the research and development challenges have been met and also extensively trialled in real situations is the major N4C achievement

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It is with satisfaction the consortium presents results that confirm our success in fulfilling the N4C goal. We present DTN and WiMAX access solutions together with genuine applications that have proven stable and run autonomously for several months in real situations and for which the options for internet access previously were limited, unsatisfactory (for instance unstable), in terms of costs unrealistic or, eventually not within physical reach.

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The range of results in N4C

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A majority of foreground investigates or relate to DTN routing, functionality and service delivery. But, related to the applied engineering dimension of the project and, in connection to real life deployments, a number of technically separate themes emerge. For instance, in an urban European setting it is quite a negligible issue that modern communication technologies are dependant on electrical power. Setting up networks beyond the conventional infra structure and electrical grid however, implies limited or no access to this commodity. To handle such situations in an energy efficient and environmentally friendly way N4C developed strategies for power harvesting, and made power management intrinsic in software as well as hardware solutions. Problem areas were also identified, where power saving strategies, are presently not available but should be researched. Furthermore, the architecture prescribes that the physical layer is regarded in the frames of opportunistic choices. WiMAX is the only wireless technology that has been the subject of research and development as such. However, the experience of wireless technology in a broader sense is part of the research and development results in certain other aspects. Notably, wireless technology protocols or frequency range are not determining factors for the N4C DTN architecture. The technology most useful for the situation and distance is determined for each case. The major choice for node-to-node communication in N4C real life test topologies was WiFi. For gateways connecting the DTN networks to the Internet, the choice is likewise to be a matter of location and situation. At least, this should be valid if the architecture works as foreseen. That this is the case was proven in several ways during the project, including a case of forced change of Internet service supplier during the project time. In the Swedish Lapland test bed, the then newly opened 450MHz digital replacement of the former Nordic Mobile Telephony (NMT) was used during the first year’s trial, with good results. The particular mast reaching to the test area vicinity was however closed down without previous notice early in N4C’s second year. But, one commercial supplier of GSM (Groupe Spécial Mobile) provides 2G services that reach the vicinity of the test area and, a normal subscription was quickly established for the transfer. For the gateway nodes to the Internet a 2G solution was the only feasible choice at hand. Depending on how the Internet connection is established and such as capacity differences connected to each choice, there will necessarily be certain differences in traffic strategies but, the opportunistic endurance of the N4C DTN architecture was proven by the success in quickly changing from 450MHz to GSM in the second year’s trials. Another thing demonstrated by the case, is the unstable supply situation even in the rims of the test area targeted for DTN supply.

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Applications have been developed and successfully trialled in real life tests. Some of these will be the property of SMEs within the N4C consortium, while the construction of others is made fully available for the public (for instance generic services as adapting e-mail for DTN). To support the use of the code, there is instructions for hardware set ups and power harvesting. Platforms have been developed where professionals can test new applications or from which network providers in rural areas can build their networks. WiMAX technology has been brought further to provide real time connectivity to isolated places, with use of repeaters and other tailoring, and to support both fixed and mobile sensor networks. One of the Beneficiaries, Trinity College Dublin, has kept a project code repository and this will remain kept in relation to their continuing DTN research. The consortium partners are presently consolidating the information about the publication of the open code and instructions. The project wiki http://wiki.n4c.eu is the project group’s own site for publication but is also open for the public. Note also that transfer has been made to SourceForge.

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In sum, the range of results includes new technology for delivery of Internet or Internet-like services; integration and simulation platforms, and open source code for DTN made available to the public; commercial results in the WiMAX area; contributions to the IRTF experimental standards in the DTN area; a test bed offer for the FIRE federation; services and applications for DTN including one commercially successful already during the project time; business and implementation models for DTN based internet access, DTN test beds in remote areas, and for applications developed in the project; one new company start-up; continuation of research, development and transfer of innovation in new EU funded projects; successful dissemination, and; impact on several academic sectors, including the social sciences.

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The absolute majority of our results are available for the public. Learn more about our Deliverables (work reports describing all from preliminary to final results) at http://www.n4c.eu/Deliverables.php

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Graphical user interface (GUI) used in the Swedish Lapland test bed

where the local Sámi population and hiking tourists were volunteers in the real life tests

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