Search results for "emso"

Cooperative Communications inWireless Local Area Networks: MAC Protocol Design and Multi-layer Solutions

2012

Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 2012 This dissertation addresses cooperative communications and proposes multi-layer solu- tions for wireless local area networks, focusing on cooperative MAC design. The coop- erative MAC design starts from CSMA/CA based wireless networks. Three key issues of cooperation from the MAC layer are dealt with: i.e., when to cooperate (opportunistic cooperation), whom to cooperate with (relay selection), and how to protect cooperative transmissions (message procedure design). In addition, a cooperative MAC protocol that addresses these three issues is proposed. The relay selection scheme is further…

Investigating Power Consumption in 802.11 WLANs: Measurement, Visualization, and Improvement

2009

Masteroppgave i informasjons- og kommunikasjonsteknologi 2009 – Universitetet i Agder, Grimstad 802.11 based wireless local area network (WLAN) has been increasingly supported by handheld devices. However, supporting WLAN functionality is extremely energy consuming since the connectivity has to be maintained even when the device is in an idle state. The power management specified in the 802.11 standards do not specify detailed techniques to handle the problem caused by power consumption affecting factors (PCAFs), since most of these factors have not been specified in the standards. The objective of this master dissertation is to investigate how different PCAFs affect the power consumption i…

Ad-hoc network for oil supply boats

2009

Masteroppgave i informasjons- og kommunikasjonsteknologi 2009 – Universitetet i Agder, Grimstad An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without any fixed infrastructure like access points or base stations. Each node in ad hoc network is willing to forward data for other nodes, and the determination of which nodes forward data is made dynamically based on the network connectivity. Mobile ad hoc networking can offer multiple advantages in various environments through its flexibility and its special nature. One such environment is maritime communications. The MARCOM Project currently has shown that a definite protocol simulation of mar…

Design a WLAN mini access point in the android platform

2010

Masteroppgave i informasjons- og kommunikasjonsteknologi 2010 – Universitetet i Agder, Grimstad Mobile as a computing platform is becoming more and more popular. The amount of such devices shipped every year is growing rapidly, more than 1.2 billion in 2009. At the same time the WLAN is being widely adapted at various locations like campuses, meeting rooms, stations, etc. Currently almost all smart phones come with the support for the WLAN. However, most the mobile devices can only behavior as a client in the WLAN. It would be a remarkable feature if the mobile device is able to function as an Access Point (AP) and a modem which forwards data between the 3G network and the WLAN. Android des…

How Vulnerable is the Reaction Time Concealed Information Test to Faking?

2021

The reaction time-based Concealed Information Test (RT-CIT) can be used to detect information a suspect wishes to conceal. While it is often argued that it is easily faked, empirical research on its vulnerability to faking is scarce. In three experiments, we tested whether receiving faking instructions enables guilty participants to fake an innocent test outcome in an RT-CIT. In Experiment 1, when not using a response deadline, we found the RT-CIT to be vulnerable to faking (d = 1.06). Experiment 2 showed that when using a response deadline, faking was ineffective (d = −0.25). Critically, Experiment 3 replicated these findings within one between-subject design, showing again a faking effect…

Sensor networks for cognitive radio : theory and system design

2008

Wireless Sensor Networks for Condition Based Maintenance: Security and Reliability

2009

Masteroppgave i informasjons- og kommunikasjonsteknologi 2009 – Universitetet i Agder, Grimstad In this thesis we present the requirements needed for a Condition Based Main- tenance (CBM) solution by using Wireless Sensor Networks(WSN). The sensor network needs to be secure and reliable to be implemented in a CBM solution, hence we have chosen the popular ZigBee protocol to see how it fulfill the reliability requirements of transmission delay, lost packets and battery consumption. The security requirements is based on the CIA(confidentiality, integrity, availability) triad for security objectives, and in this thesis we will give a general overview of the security mechanisms used in ZigBee t…

Performance evaluation of robust header compression protocol for low data rate networks

2013

Masteroppgave i informasjons- og kommunikasjonsteknologi IKT590 2013 – Universitetet i Agder, Grimstad Mobile Ad hoc networks (MANETs) have limited capacity due to properties of the physical medium for tactical operations. Several traffic types are typical for tactical applications, i.e. transmit frequent short IP packets (e.g., VoIP and friendly force tracking message). The RTP, TCP/UDP and IP headers comprise a significant overhead for these traffic types. Therefore, robust header compression (ROHC) protocol can useful to save the bandwidth for such applications. This thesis work is divided into two tasks. First one is the technological background of the robust header compression (ROHC) p…

A dynamic parallel-rendezvous MAC mechanism in multi-rate cognitive radio networks: Mechanism design and performance evaluation

2009

Published version of an article published in the journal:Journal of Communications, © Academy Publisher Also available from publisher: http://dx.doi.org/10.4304/jcm.4.10.752-765 Parallel rendezvous multi-channel MAC mechanisms are regarded as an efficient method for media access control in cognitive radio networks since they do not need a control channel and use only one transceiver. However, existing parallel rendezvous MAC mechanisms assume that all channels have the same maximum capacity and channel availability for secondary users. In this paper, we propose a dynamic parallel rendezvous multi-channel MAC mechanism for synchronized multi-rate cognitive radio networks in which secondary u…

Energy Efficiency inWireless Sensor Networks: Transmission Protocols and Performance Evaluation

2016

Doktorgradsavhandling, Fakultet for teknologi og realfag, Universitetet i Agder, 2016 Energy efficiency is one of the major goals for achieving green wireless communications. The recent growth in ubiquitous wireless connections and multimedia applications demands higher energy efficiency for wireless communications. As a part of this picture, wireless sensor networks (WSNs) need to be more energy efficient since the battery capacity of nodes in such networks is limited in the absence of energy harvesting sources. In general, an energy efficient protocol should perform as few as possible operations when delivering user information successfully across the network. Energy efficient data transm…