Search results for "Computer network"
showing 10 items of 1634 documents
Lightweight Relay Selection in Multi-Hop Wake-Up Radio Enabled IoT Networks
2018
Wake-up Radios (WuRs) are becoming more popular in Internet of Things (IoT) networks owing to their overwhelming advantages such as low latency, high energy saving, and on-demand communication. In a multi-hop WuR-IoT network, route establishment between source and destination prior to actual data communications consumes a significant portion of energy. To reduce energy consumption and protocol overhead for route establishment, we propose a lightweight relay (LR) selection scheme, referred to as LR-WuR, where a lookup table and acknowledgment are used for next hop relay selection. We develop an analytical model to evaluate the performance of LR-WuR. Extensive simulations are performed to val…
Multi-Antenna Covert Communication With Jamming in the Presence of a Mobile Warden
2021
Covert communication can hide the information transmission process from the warden to prevent adversarial eavesdropping. However, it becomes challenging when the warden can move. In this paper, we propose a covert communication scheme against a mobile warden, which maximizes the connectivity throughput between a multi-antenna transmitter and a full-duplex jamming receiver with the covert outage probability (COP) limit. First, we analyze the monotonicity of the COP to obtain the optimal location the warden can move. Then, under this worst situation, we optimize the transmission rate, the transmit power and the jamming power of covert communication to maximize the connection throughput. This …
Towards a SDN-based architecture for analyzing network traffic in cloud computing infrastructures
2015
Currently, network traffic monitoring tools do not fit well in the monitoring of cloud computing infrastructures. These tools are not integrated with the control plane of the cloud computing stack. This lack of integration causes a deficiency in the handling of the re-usage of IP addresses along virtual machines, a lack of adaption and reaction on highly frequent topology changes, and a lack of accuracy in the metrics gathered for the networking traffic flowing along the cloud infrastructure. The main contribution of this paper is to provide a novel SDN-based architecture to carry out the monitoring of network traffic in cloud infrastructures. The architecture in based on the integration be…
Repair Mechanisms for Broadcast Transmissions in Hybrid Cellular & DVB-H Systems
2006
This paper proposes a framework for investigating potential infrastructure cost savings in hybrid cellular and DVB- H systems by performing efficient error repair of broadcast transmissions. The main idea is to reuse as much as possible the existing network infrastructure to provide mobile TV services. The cellular system is not only employed to collect information, but also to send repair data to the users whose conditions are temporarily affected by noise, interference and fading. To enable an easy and efficient implementation of the repair mechanisms we adopt the use of application layer - forward error correction (AL-FEC) with digital fountain coding.
Application Layer FEC for Mobile TV Delivery in IP Datacast Over DVB-H Systems
2009
In this paper we investigate the potential gain that can be obtained in DVB-H using application layer forward error correction (AL-FEC) to perform a multi-burst protection of the transmission for improving the reception of streaming services for mobile terminals. Compared to the conventional approach with link layer multi protocol encapsulation FEC (MPE-FEC), this technique allows to increase the robustness of the DVB-H transmission not only as a function of the capacity devoted for error repair (FEC overhead), but also as a function of the number of bursts jointly encoded. The main drawback of this approach is an increase of the network latency, that can be translated into a larger service…
A spatial role-based authorization framework for sensor network-assisted indoor WLANs
2009
©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Article also available from publisher: http://dx.doi.org/10.1109/WIRELESSVITAE.2009.5172549 In this paper, we propose a spatial role-based authorization framework which specifies authorization based on both role and location constrains in a wireless local area network with assistance from a sensor network. The framework performs a location-restricted verificati…
Defending Surveillance Sensor Networks Against Data-Injection Attacks Via Trusted Nodes
2018
By injecting false data through compromised sensors, an adversary can drive the probability of detection in a sensor network-based spatial field surveillance system to arbitrarily low values. As a countermeasure, a small subset of sensors may be secured. Leveraging the theory of Matched Subspace Detection, we propose and evaluate several detectors that add robustness to attacks when such trusted nodes are available. Our results reveal the performance-security tradeoff of these schemes and can be used to determine the number of trusted nodes required for a given performance target.
Improving Chord Lookup Protocol for P2PSIP-Based Communication Systems
2009
Chord has been suggested as mandatory overlay technology in the future P2PSIP-based communication systems. Chord allows for the available peer/resource lookup in no more than hops, where N is the total number of the peers in the overlay network. However, as a protocol originally designed for background downloading applications, Chord has a few drawbacks when supporting P2PSIP real-time communication systems. These drawbacks are related to ID assignment, the relation between ID and physical location, the routing styles and lack of cache, etc. In this paper, we investigate several approaches that can improve the efficiency of the peer/resource lookup algorithm. After that, we simulate two sys…
Joint routing and per-flow fairness in wireless multihop networks
2008
In wireless multihop networks communication between two end-nodes is carried out by hopping over multiple short wireless links. Traditional CSMA/CA based media access control does not work satisfactory in a multihop scenario, since an intended target of a communication may be subject to mutual interference imposed by concurrent transmissions from nodes which cannot directly sense each other, causing unfair throughput allocation. Although TDMA seems to be a more promising solution, careful transmission scheduling is needed in order to achieve error-free communication and fairness. In our previous work, a TDMA scheduling algorithm has been proposed that schedules the transmissions in a fair m…
On Unstructured File Sharing Networks
2007
We study the interaction among users of unstructured file sharing applications, who compete for available network resources (link bandwidth or capacity) by opening multiple connections on multiple paths so as to accelerate data transfer. We model this interaction with an unstructured file sharing game. Users are players and their strategies are the numbers of sessions on available paths. We consider a general bandwidth sharing framework proposed by Kelly [1] and Mo and Walrand [2], with TCP as a special case. Furthermore, we incorporate the Tit-for-Tat strategy (adopted by BitTorrent [3] networks) into the unstructured file sharing game to model the competition in which a connection can be …