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Location-based applications (e.g., foursquare, Groupon) rely on each client's assertion of his or her location (e.g., uploaded GPS coordinates). Yet these service providers seek methods to authenticate the location of clients to enhance targeted service delivery and support their advertisers. We propose an intelligent infrastructure-based solution that provides spontaneous, transaction-oriented, collusion-resistant...
Software routers (SRs) are an alternative low-cost and moderate-performance router solutions implemented with general-purpose workstations able to host multiple network interface cards (NICs). Workstations can be programmed to forward packets between different NICs and to participate in routing functions. Virtualization can be used to model new protocols or hardware systems in software and without...
We present a novel approach to heterogeneous networks study based on the implementation of a modular, extensible, and scalable testbed that uses virtualized network emulators. Our goal is to reproduce complex networks scenarios by interconnecting several emulators, concurrently running within a single hardware platform. This paper analyzes the testbed performance with simple emulation trials, to verify...
In this paper, a congestion-aware rerouting (CAR) scheme is proposed based on the fairness mechanism of RPR for better throughput. If all flows competing for the bandwidth of the congested link converge to the steady rate, we try to find an alternate path to gain more bandwidth than the current path for some traffic flow passing through the congested link. Meanwhile, the throughput of flows traversing...
We present an analytical model to evaluate the performance of the IEEE 802.11 Distributed Coordination Function (DCF) with and without the RTS/CTS handshake in radio-over-fiber (RoF) wireless LANs. The model captures the effects of contending nodes as well as hidden terminals under non-saturated traffic conditions assuming large buffer sizes. The effect of fiber propagation delay is considered. The...
In this paper the performance of a hybrid optical network composed of multiple Ethernet Passive Optical Networks (EPONs) at the access connected to an Optical Burst Switching (OBS) core is evaluated. The EPONs make use of the IPACT algorithm to manage the upstream transmissions, whereas the OBS edge node employs a time-based assembly scheme for burst aggregation. This leads to interoperability issues...
With users increasingly focused on an online world, an emerging challenge for the network infrastructure is the need to support Massively Multiplayer Online Role Playing Games (MMORPG). This is an application domain that is attracting more players than ever before, very often with players distributed over a metropolitan area. Currently, MMORPG are built on an IP infrastructure with the primary responsibility...
In today's Internet the commercial aspect of routing is gaining more and more importance. Commercial agreements between ISPs (i.e. transit and peering agreements) influence the inter-domain routing policies which are now driven by monetary aspects as well as global resource and performance optimization. To allow scalability and protect business critical topology information, hierarchical routing and...
The Forthroid is a location-based system that “augments” physical objects with multimedia information and enables users to receive information about physical objects or request services related to physical objects. It employs computer-vision techniques and Quick Response codes (QR-codes). We have implemented a prototype on Android platforms and evaluated its performance with systems metrics and subjective...
We propose a scale-out solution for deep packet processing (DPP) appliances, which uses a standard Ethernet switch in combination with a load balancing controller. The majority of the data-plane traffic is distributed via the switch's built-in traffic distribution function and no connection state is kept. If the load balancing controller detects a skew in the load of the DPP appliances, it updates...
The performance evaluation of mobile communication systems for time varying environments poses a major challenge. To address this issue, in this paper we propose an approach which extends a common laboratory environment by a fading channel emulator. Hereby, we analyze OFDM based links under complex and realistic radio channel conditions including upper layer protocols. By means of this setup, the...
The end to end system data performance over a 3G cellular network depends on many factors such as the number of users, interference, multipath propagation, radio resource management techniques as well as the interaction between these mechanisms and the transport protocol's flow and congestion mechanisms. Using controlled experiments in a public cell site, we investigate the interaction between TCP...
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