Scholarly Work - Computer Science
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/3034
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Item MIST: Cellular data network measurement for mobile applications(Conference on Broadband Communications, Networks and Systems (BROADNETS), 2007-09) Wittie, Mike P.; Stone-Gross, Brett; Almeroth, Kevin C.; Belding, Elizabeth M.The rapid growth in the popularity of cellular networks has led to aggressive deployment and a rapid expansion of mobile services. Services based on the integration of cellular networks into the Internet have only recently become available, but are expected to become very popular. One current limitation to the deployment of many of these services is poor or unknown network performance, particularly in the cellular portion of the network. Our goal in this paper is to motivate and present the Mobile Internet Services Test (MIST) platform, a new distributed architecture to measure and characterize cellular network performance as experienced by mobile devices. We have used MIST to conduct preliminary measurements; evaluate MIST’s effectiveness; and motivate further measurement research.Item On The Implications of Routing Metric Staleness in Delay Tolerant Networks(Elsevier, 2009) Wittie, Mike P.; Harras, Khaled A.; Almeroth, Kevin C.; Belding, Elizabeth M.Delay Tolerant Network (DTN) routing addresses challenges of providing end-to-end service where end-to-end data forwarding paths may not exist. The performance of current DTN routing protocols is often limited by routing metric ‘‘staleness”, i.e., routing information that becomes out-of-date or inaccurate because of long propagation delays. Our previous work, ParaNets, proposed a new opportunistic network architecture in which the data channel is augmented by a thin end-to-end control channel. The control channel is adequate for the exchange of control traffic, but not data. In this paper we present Cloud Routing, a routing solution for the ParaNets architecture. We motivate the need for such a solution, not only because of stale routing metrics, but also because of congestion that can occur in DTNs. Unable to use up-to-date routing metrics to limit congestion, existing DTN routing solutions suffer from low goodput and long data delivery delays. We show how Cloud Routing avoids congestion by smart use of forwarding opportunities based on up-to-date routing metrics. We evaluate our solution using extensive OPNET simulations. Cloud Routing extends network performance past what is currently possible and motivates a new class of globally cognizant DTN routing solutions.Item Internet Service in Developing Regions Through Network Coding(IEEE, 2009) Wittie, Mike P.; Almeroth, Kevin C.; Belding, Elizabeth M.; Rimac, Ivica; Hilt, VolkerThe availability of Internet services brings many benefits to developing regions, yet Internet deployment levels in these regions remain staggeringly low. In this work we investigate how existing cellular deployments, which have enjoyed more rapid and wider deployment than client Internet infrastructure, could be used to provide very low cost Internet services in underdeveloped rural areas. We propose a new service model in which traffic is delivered over multihop client-to-client connections that are coordinated by end-to-end control traffic exchanged over cellular infrastructure. To enable this scheme in low client density rural settings, we propose a novel data forwarding mechanism for opportunistic space-time paths. To explore multiple opportunistic paths, but without the high forwarding cost of replicating data on these paths, we use network coding and send only a fraction of the data on each path. Through extensive OPNET simulations we show that globally coordinated opportunistic forwarding enables service acceptable to most applications at only a fraction of cellular infrastructure load. We argue that the reduced load on the cellular infrastructure allows additional users to share services and cost of the network and has the potential to lower the per user price of data services in developing regions.Item ParaNets: A parallel network architecture for challenged networks(IEEE, 2007-03) Harras, Khaled A.; Wittie, Mike P.; Almeroth, Kevin C.; Belding, Elizabeth M.Networks characterized by challenges, such as intermittent connectivity, network heterogeneity, and large delays, are called “challenged networks”. We propose a novel network architecture for challenged networks dubbed Parallel Networks, or, ParaNets. The vision behind ParaNets is to have challenged network protocols operate over multiple heterogenous networks, simultaneously available, through one or more devices. We present the ParaNets architecture and discuss its short-term challenges and long-term implications. We also argue, based on current research trends and the ParaNets architecture, for the evolution of the conventional protocol stack to a more flexible cross-layered protocol tree. To demonstrate the potential impact of ParaNets, we use Delay Tolerant Mobile Networks (DTMNs) as a representative challenged network over which we evaluate ParaNets. Our ultimate goal in this paper is to open the way for further work in challenged networks using ParaNets as the underlying architecture.