5,109 research outputs found
The effect of group mobility on the efficacy of routing in next generation mobile networks
© 2016 IEEE.A key challenge in next generation mobile networks is ensuring effective routing that efficiently adapts to the special characteristics of the various mobility schemes. The purpose of this paper is to study and illustrate how group mobility affects the network performance of a wireless ad hoc network depending on the type of movement, in a space with or without obstacles. In the scope of this paper, we created a simulator of a MANET that uses AODV routing protocol, while the entities of the network move according to the chosen group mobility model. Despite the fact that the routing protocol supports mobility in general, the results greatly vary depending on the specific mobility scenario. The strong connection between mobility properties and network performance is revealed
Defending against Sybil Devices in Crowdsourced Mapping Services
Real-time crowdsourced maps such as Waze provide timely updates on traffic,
congestion, accidents and points of interest. In this paper, we demonstrate how
lack of strong location authentication allows creation of software-based {\em
Sybil devices} that expose crowdsourced map systems to a variety of security
and privacy attacks. Our experiments show that a single Sybil device with
limited resources can cause havoc on Waze, reporting false congestion and
accidents and automatically rerouting user traffic. More importantly, we
describe techniques to generate Sybil devices at scale, creating armies of
virtual vehicles capable of remotely tracking precise movements for large user
populations while avoiding detection. We propose a new approach to defend
against Sybil devices based on {\em co-location edges}, authenticated records
that attest to the one-time physical co-location of a pair of devices. Over
time, co-location edges combine to form large {\em proximity graphs} that
attest to physical interactions between devices, allowing scalable detection of
virtual vehicles. We demonstrate the efficacy of this approach using
large-scale simulations, and discuss how they can be used to dramatically
reduce the impact of attacks against crowdsourced mapping services.Comment: Measure and integratio
MELOC - memory and location optimized caching for mobile Ad hoc networks
The advancement of Mobile ad hoc networks (MANET) is tremendous in the field of social and military applications. Caching and Replication are the two common techniques used to improve data access efficiency in Mobile Ad hoc networks. Caching favors data access efficiency by bringing data closer to the source. Existing caching approaches are deficient in reducing the number of cache locations, thus reducing the number of copies, which is needed for many mission critical applications considering safety and security. Conversely, reducing the number of caches should not affect the efficiency of data access. We design an efficient broker based caching model named Memory and Location Optimized Caching (MELOC) , which reduces the number of cache locations, and at the same time preserves data access efficiency. Our caching model mostly chooses centrally located nodes as cache location. In addition, we cache only essential data closer to the source, saving memory. Hence our approach bears the name Memory and Location Optimized caching (MELOC) . Our initial MELOC model suits only small MANET topology of 30 nodes. We further extend our initial caching model to suit large MANET topology of 100 nodes by overcoming certain disadvantages pertaining to large network topology --Abstract, page iv
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