published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

published_or_final_version / Computer Science / Master / Master of Philosophy

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

Wireless Mesh Networks (WMNs) are bringing revolutionary change in the field of wireless networking. It is a trustworthy technology in applications like broadband home networking, network management and latest transportation systems. WMNs consist of mesh routers, mesh clients and gateways. It is a special kind of wireless Ad-hoc networks. One of the issues in WMNs is resource management which includes routing and for routing there are particular routing protocols that gives better performance when checked with certain parameters. Parameters in WMNs include delay, throughput, network load etc. There are two types of routing protocols i.e. reactive protocols and proactive protocols. Three routing protocols AODV, DSR and OLSR have been tested in WMNs under certain parameters which are delay, throughput and network load. The testing of these protocols will be performed in the Optimized Network Evaluation Tool (OPNET) Modeler 14.5. The obtained results from OPNET will be displayed in this thesis in the form of graphs. This thesis will help in validating which routing protocol will give the best performance under the assumed conditions. Moreover this thesis report will help in doing more research in future in this area and help in generating new ideas in this research area that will enhance and bring new features in WMNs. / Wireless Mesh Networks (WMNs) bringar revolutionerande förändring inom området för trådlösa nätverk. Det är en pålitlig teknik i tillämpningar såsom bredband hemma nätverk, nätverkshantering och senaste transportsystem. WMNs består av mesh routrar, kunder mesh och gateways. Det är en speciell typ av trådlöst ad-hoc-nätverk. En av frågorna i WMNs är resurshushållning som inkluderar routing och routing det finns särskilda routingprotokoll som ger bättre prestanda vid kontroll med vissa parametrar. Parametrar i WMNs omfatta dröjsmål, genomströmning, belastningen på nätet etc. Det finns två typer av routingprotokoll dvs reaktiva protokoll och proaktiva protokoll. Tre routingprotokoll AODV, DSR och OLSR har testats i WMNs under vissa parametrar som är försenade, genomströmning och belastningen på nätet. Testning av dessa protokoll kommer att utföras i den optimerade Network Evaluation Tool (OPNET) Modeler 14.5. De erhållna resultaten från OPNET kommer att visas i denna avhandling i form av grafer. Denna uppsats kommer att bidra till att godkänna vilka routingprotokoll kommer att ge bäst resultat enligt den antagna förhållanden. Dessutom kommer denna uppsats rapport kommer att bidra till att göra mer forskning i framtiden på detta område och bidra till att generera nya idéer inom detta forskningsområde som kommer att öka och att nya funktioner i WMNs. / +46762749245

This report discusses the design and development of the software implementation for a wireless communication system that integrates seamlessly with the TLL5000 Platform available in the University of Texas Embedded Microsystems Lab. While there are a number of features already available on these circuit boards for a wide variety of applications, there is currently no system in place for transmitting data wirelessly from one circuit board to another. The system examined in this report is comprised of an external transmit/receive daughterboard that communicates with a software application running on the TLL-SILC 6219 ARM processor that is already interfaced with the TLL5000 baseboard. This report discusses the implementation of the various physical-layer communication techniques that are utilized by the software application to both transmit and receive data through the external daughterboard. / text

Wireless scheduling is a fundamental problem in wireless networks that involves scheduling transmissions of multiple users in order to support data flows with as high rates as possible. This problem was first addressed by Tassuilas and Ephremides, resulting in the celebrated Back-Pressure network scheduling algorithm. This algorithm schedules network links to maximize throughput in an opportunistic fashion using instantaneous network state information (NSI), i.e., queue and channel state knowledge across the entire network. However, the Back-Pressure (BP) algorithm suffers from various drawbacks - (a) it requires knowledge of instantaneous NSI from the whole network, i.e. feedback about time-varying channel and queue states from all links of the network, (b) the algorithm requires solving a global optimization problem at each time to determine the schedule, making it highly centralized. Further, Back-pressure algorithm was originally designed for wireless networks where interference is modeled using protocol interference model. As recent break-throughs in full-duplex communications and interference cancelation techniques provide greatly increased capacity and scheduling flexibility, it is not clear how BP algorithm can be modified to improve the data rates and reduce the delay. In this thesis, we address the drawbacks of Back-Pressure algorithm to some extent. In particular, our first work provides a new scheduling algorithm (similar to BP) that allows users to make individual decisions (distributed) based on heterogeneously delayed network state information (NSI). Regarding the complexity issue, in our second work, we analyze the performance of the greedy version of BP algorithm, known as Greedy Maximal Scheduling (GMS) and understand the effect of channel variations on the performance of GMS. In particular, we characterize the efficiency ratio of GMS in wireless networks with fading. In our third and fourth work, we propose and analyze new scheduling algorithms that can benefit from new advancements in interference cancelation techniques. / text