Spelling suggestions: "subject:"wireless mest""
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Analysis of hardware requirements for airborne tactical mesh networking nodes / An analysis of tactical mesh networking hardware requirements for airborne mobile nodesMilicic, Gregory J. 03 1900 (has links)
Approved for public release, distribution is unlimited / Wireless mesh mobile ad hoc networks (MANETs) provide the military with the opportunity to spread information superiority to the tactical battlespace in support of network-centric warfare (NCW). These mesh networks provide the tactical networking framework for providing improved situational awareness through ubiquitous sharing of information including remote sensor and targeting data. The Naval Postgraduate School's Tactical Network Topology (TNT) project sponsored by US Special Operations Command seeks to adapt commercial off the shelf (COTS) information technology for use in military operational environments. These TNT experiments rely on a variety of airborne nodes including tethered balloon and UAVs such as the Tern to provide reachback from nodes on the ground to the Tactical Operations Center (TOC) as well as to simulate the information and traffic streams expected from UAVs conducting surveillance missions and fixed persistent sensor nodes. Airborne mesh nodes have unique requirements that can be implemented with COTS technology including single board computers and compact flash. / Lieutenant, United States Navy
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An analysis of the feasibility of implementing ultra wideband and mesh network technology in support of military operationsHerzig, Joseph F., Jr. 03 1900 (has links)
Approved for public release, distribution is unlimited / This thesis analyzes the feasibility, functionality, and usability of Ultra Wideband technology as an alternative to 802.11 in wireless mesh networks for multiple DoD contexts. Ultra wideband and wireless mesh network technologies and applications are researched and analyzed through multiple field and lab experiments for usability in current, real-world situations. Hardware and software investigations are conducted to determine any implementation issues between ultra wideband and wireless mesh networks. A detailed assessment is conducted of the various elements and operational constraints for developing an ultra wideband mesh network that can be utilized to improve situational awareness in network-centric operations. Through joint research with Lawrence Livermore National Laboratories, various hardware and software components are developed to create a test bed for tactical level ultra wideband and mesh networking experimentation in a highly mobile environment. This thesis also lays the groundwork into future ultra wideband and mesh networking applications. / Lieutenant, United States Navy
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An analysis of network and sensor performance within IEEE 802.x wireless MESH networks in the Tactical Network Topology (TNT)Davis, Joseph A., Sr. 03 1900 (has links)
Approved for public release, distribution is unlimited / The objective of this research is to analyze the network performance and sensor functionality, efficacy and usability of IEEE 802.x wireless MESH networks within a DoD Tactical network environment. Multiple sensor configurations operating with wireless MESH network technologies will be researched and analyzed for performance in expeditionary environment situations. Specifically, this thesis will attempt establish the foundation for the development of wireless MESH "network health" models by examining the performance of sensors operating within a MESH network and define which network performance metrics equate to good quality of service. This research will experiment with different application, sensor, and network configurations of currently available COTS components, such as, voice, video and data hardware. This thesis will lay the groundwork for wireless network MESH predictability, which will enable the optimal use of sensors within a tactical network environment. / Lieutenant Commander, United States Navy
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Dynamic power control in backbone wireless mesh networks : a decentralized approach / Le contrôle de pouvoir dynamique dans la radio de colonne vertébrale fait concorder des réseaux : une approche décentraliséeOlwal, Thomas 15 December 2010 (has links)
L'évolution importante des réseaux sans fil tend à fournir les supports nécessaires aux applications ubiquitaires émergentes dans les réseaux Mesh sans fil. Les réseaux mesh comprennent des nœuds stationnaires qui remplissent la fonction de routage et appelés routeurs Mesh sans fil (WMR) et qui consitutent le réseau backbone sans fil (WBMN) ainsi que des nœuds clients mesh sans fil (WMCs). Alors que les WMCs sont limités en termes de fonctions et de resources radio, les WMRS fournissent des fonctions de pont et de passerelle afin de connecter les réseaux WMNs aux autres réseaux comme les réseaux cellulaires, les réseaux IEEE 802.11, les réseaux IEEE 802.16, ou tout simplement à Internet. Par conséquent, les réseaux WMRs sont construits à partir sur la base d'équipement radio de communication rapide et/ou multi-radio et multi-canaux. Les routeurs WMRs sont supposes être auto-organisés, auto-configurés et constituant un réseau WNMN robuste ce qui nécessite de soutenir des volumes importants de trafic de données et sur de longues périodes. Cependant, répondre à attentes élevées en termes de services nécessite le développement d'approches décentralisés pour le control dynamique des puissances de transmission (DTPC). La présente thèse se focalise sur le problème DTPC pour les deux cas de réseaux; utilisant un canal de communication et multicanaux. Pour les réseaux exploitant un seul canal, le problème est formulé en termes de problème d'optimisation où l'objectif est de minimiser en même temps des critères convexes associés aux liens et aux réseaux. Afin de résoudre ce problème, des modèles et des algorithmes, appelés MATA (multiple access transmission aware), ont été proposés. Pour les réseaux WBMNs utilisant des systèmes multi-radio et multi-canaux (MRMC), le réseau est modélisé par un ensemble de graphes appelés UCGs (unified channel graphs), chacun consistant les utilisateurs connectés au point d'accès en utilisant le même canal fréquentiel. Pour chaque ensemble UCG, le problème à résoudre un problème quadratique et stochastique soumis aux contraintes des états des liens dynamiques LSI (Link State Information) de tous les UCGs. Le protocole PMMUP, mutli-radio et minimisant la consummation énegétique, est propose au niveau de la couche liaison. Algorithmes d'estimation prédictive base sur ce protocol sont proposes pour résoudre les problèmes d'optimisation associés aux UGCs. Les problèmes énergétiques, les instabilités des queues et les interférences, sont formulés en termes de problèmes de commande optimale couplée, appelés SPWC (singularly-perturbed weakly-coupled). Pour résoudre les problèmes SPWC caractérisant le problème de commande optimal des energies de transmission, l'algorithme HORA (aeneralized higher-order recursive algorithm) qui permet d'obtenir les solutions stables pour les équations de Riccati a été développé. Les performes des modèles et algorithmes proposés dans le cadre de la présente thèse ont été évalués tant sur le plan théorique qu'en simulation. Différentes simulations ont été effectuées sur un large ensemble de topologies réseaux générés aléatoirement. Les résultats de simulation et analytiques Simulation confirment l'efficacité des algorithmes proposés par rapport à la majorité des techniques existantes / The remarkable evolution of wireless networks into the next generation to provide ubiquitous and seamless broadband applications has recently triggered the emergence of Wireless Mesh Networks (WMNs). The WMNs comprise stationary Wireless Mesh Routers (WMRs) forming Wireless Backbone Mesh Networks (WBMNs) and mobile Wireless Mesh Clients (WMCs) forming the WMN access. While WMCs are limited in function and radio resources, the WMRs are expected to support heavy duty applications : that is, WMRs have gateway and bridge functions to integrate WMNs with other networks such as the Internet, cellular, IEEE 802.11, IEEE 802.15, IEEE 802.16, sensor networks, et cetera. Consequently, WMRs are constructed from fast switching radios or multiple radio devices operating on multiple frequency channels. WMRs are expected to be self-organized, self-configured and constitute a reliable and robust WBMN which needs to sustain high traffic volumes and long “online” time. However, meeting such stringent service expectations requires the development of decentralized dynamic transmission power control (DTPC) approaches. This thesis addresses the DTPC problem for both single and multiple channel WBMNs. For single channel networks, the problem is formulated as the minimization of both the link-centric and network-centric convex cost function. In order to solve this issue, multiple access transmission aware (MATA) models and algorithms are proposed. For multi-radio multi-channel (MRMC) WBMNs, the network is modelled as sets of unified channel graphs (UCGs), each consisting of interconnected active network users communicating on the same frequency channel. For each UCG set, the minimization of stochastic quadratic cost functions are developed subject to the dynamic Link State Information (LSI) equations from all UCGs. An energy-efficient multi-radio unification protocol (PMMUP) is then suggested at the Link-Layer (LL). Predictive estimation algorithms based on this protocol are proposed to solve such objective functions. To address transmission energy and packet instabilities, and interference across multiple channels, singularly-perturbed weakly-coupled (SPWC) control problems are formulated. In order to solve the SPWC transmission power control problem, a generalized higher-order recursive algorithm (HORA) that obtains the Riccati Stabilizing Solutions to the control problem is developed. The performance behaviours of the proposed models and algorithms are evaluated both analytically and through computer simulations. Several simulations are performed on a large number of randomly generated topologies. Simulation and analytical results confirm the efficacy of the proposed algorithms compared to the most recently studied techniques
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Le support de VoIP dans les réseaux maillés sans fil WiMAX en utilisant une approche de contrôle et d'assistance au niveau MACHaddouche, Fayçal 04 1900 (has links)
Les réseaux maillés sans fil (RMSF), grâce à leurs caractéristiques avantageuses, sont considérés comme une solution efficace pour le support des services de voix, vidéo et de données dans les réseaux de prochaine génération. Le standard IEEE 802.16-d a spécifié pour les RMSF, à travers son mode maillé, deux mécanismes de planifications de transmission de données; à savoir la planification centralisée et la planification distribuée. Dans ce travail, on a évalué le support de la qualité de service (QdS) du standard en se focalisant sur la planification distribuée. Les problèmes du système dans le support du trafic de voix ont été identifiés. Pour résoudre ces problèmes, on a proposé un protocole pour le support de VoIP (AVSP) en tant qu’extension au standard original pour permettre le support de QdS au VoIP. Nos résultats préliminaires de simulation montrent qu’AVSP offre une bonne amélioration au support de VoIP. / Wireless mesh networks (WMNs), because of their advantageous characteristics, are considered as an effective solution to support voice services, video and data in next generation networks. The IEEE 802.16-d specified for WMNs, through its mesh mode, two mechanisms of scheduling data transmissions; namely centralized scheduling and distributed scheduling. In this work, we evaluated the support of the quality of service (QoS) of the standard by focusing on distributed scheduling. System problems in the support of voice traffic have been identified. To solve these problems, we proposed a protocol for supporting VoIP, called Assisted VoIP Scheduling Protocol (AVSP), as an extension to the original standard to support high QoS to VoIP. Our preliminary simulation results show that AVSP provides a good improvement to support VoIP.
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Joint Congestion Control, Routing And Distributed Link Scheduling In Power Constrained Wireless Mesh NetworksSahasrabudhe, Nachiket S 11 1900 (has links)
We study the problem of joint congestion control, routing and MAC layer scheduling in multi-hop wireless mesh networks, where the nodes in the network are subjected to energy expenditure rate constraints. As wireless scenario does not allow all the links to be active all the time, only a subset of given links can be active simultaneously. We model the inter-link interference using the link contention graph. All the nodes in the network are power-constrained and we model this constraint using energy expenditure rate matrix. Then we formulate the problem as a network utility maximization (NUM) problem. We notice that this is a convex optimization problem with affine constraints. We apply duality theory and decompose the problem into two sub-problems namely, network layer congestion control and routing problem, and MAC layer scheduling problem. The source adjusts its rate based on the cost of the least cost path to the destination where the cost of the path includes not only the prices of the links in it but also the prices associated with the nodes on the path. The MAC layer scheduling of the links is carried out based on the prices of the links. The optimal scheduler selects that set of non-interfering links, for which the sum of link prices is maximum.
We study the effects of energy expenditure rate constraints of the nodes on the maximum possible network utility. It turns out that the dominant of the two constraints namely, the link capacity constraint and the node energy expenditure rate constraint affects the network utility most.
Also we notice the fact that the energy expenditure rate constraints do not affect the nature of optimal link scheduling problem. Following this fact, we study the problem of distributed link scheduling. Optimal scheduling requires selecting independent set of maximum aggregate price, but this problem is known to be NP-hard. We first show that as long as scheduling policy selects the set of non-interfering links, it can not go unboundedly away from the optimal solution of network utility maximization problem. Then we proceed and evaluate a simple greedy scheduling algorithm. Analytical bounds on performance are provided and simulations indicate that the greedy heuristic performs well in practice.
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在WMN網路上考量功率及負載之路由協定 / An Efficient POwer-Load-Aware Routing Protocol (POLAR) for Wireless Mesh Networks吳耀先, Wu,Yao-Hsien Unknown Date (has links)
為了降低無線網路基地台後端之backhaul成本及解決Ad hoc網路涵蓋面積問題,無線網狀網路WMNs(Wireless Mesh Networks)因此應運而生。WMNs網路上的節點裝置與Ad hoc網路上的行動裝置對電量消耗及負載的需求是非常不同的,所以在Ad hoc網路上可使用之路由協定在WMNs網路上是無法直接適用的。
在Pure Ad hoc網路上考量Power之MMBCR(Min-Max Battery Cost Routing)及考量Loading之CSLAR(Contention Sensitive Load Aware Routing)等路由協定並沒有考量到WMNs網路上不同元件間的不同特性。有鑑於此,我們著重在Hybrid WMNs網路環境上,並提出了在Mesh Clients及Routers上同時考量Power及Loading的路徑演算法,我們稱之為POLAR。實驗結果顯示我們的路由協定能夠提昇整體的網路效能及延長網路存活時間。 / In order to reduce the backhaul cost and solve Ad hoc network coverage problem, WMNs (Wireless Mesh Networks) arise at the historic moment. The requirements on power efficiency and loading are much different between mesh nodes of WMNs and mobile hosts of ad hoc networks. The routing protocol used in Ad hoc networks would be not suitable in WMN networks.
The power-aware routing in MMBCR (Min-Max Battery Cost Routing) and load-aware routing in CSLAR (Contention Sensitive Load Aware Routing) used in pure Ad hoc networks don‘t consider the different characteristics of the components in WMNs. In view of this, we focus on the Hybrid WMNs environment, and propose a combined POwer-Aware with Load-Aware Routing algorithm (Called POLAR) along mesh clients and routers. The experimental results show that our routing protocol can enhance the network efficiency and lengthen the network live time.
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Le support de VoIP dans les réseaux maillés sans fil WiMAX en utilisant une approche de contrôle et d'assistance au niveau MACHaddouche, Fayçal 04 1900 (has links)
Les réseaux maillés sans fil (RMSF), grâce à leurs caractéristiques avantageuses, sont considérés comme une solution efficace pour le support des services de voix, vidéo et de données dans les réseaux de prochaine génération. Le standard IEEE 802.16-d a spécifié pour les RMSF, à travers son mode maillé, deux mécanismes de planifications de transmission de données; à savoir la planification centralisée et la planification distribuée. Dans ce travail, on a évalué le support de la qualité de service (QdS) du standard en se focalisant sur la planification distribuée. Les problèmes du système dans le support du trafic de voix ont été identifiés. Pour résoudre ces problèmes, on a proposé un protocole pour le support de VoIP (AVSP) en tant qu’extension au standard original pour permettre le support de QdS au VoIP. Nos résultats préliminaires de simulation montrent qu’AVSP offre une bonne amélioration au support de VoIP. / Wireless mesh networks (WMNs), because of their advantageous characteristics, are considered as an effective solution to support voice services, video and data in next generation networks. The IEEE 802.16-d specified for WMNs, through its mesh mode, two mechanisms of scheduling data transmissions; namely centralized scheduling and distributed scheduling. In this work, we evaluated the support of the quality of service (QoS) of the standard by focusing on distributed scheduling. System problems in the support of voice traffic have been identified. To solve these problems, we proposed a protocol for supporting VoIP, called Assisted VoIP Scheduling Protocol (AVSP), as an extension to the original standard to support high QoS to VoIP. Our preliminary simulation results show that AVSP provides a good improvement to support VoIP.
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An optimisation approach to improve the throughput in wireless mesh networks through network coding / van der Merwe C.Van der Merwe, Corna January 2011 (has links)
In this study, the effect of implementing Network Coding on the aggregated throughput in Wireless
Mesh Networks, was examined. Wireless Mesh Networks (WMNs) are multiple hop wireless networks,
where routing through any node is possible. The implication of this characteristic, is that messages
flow across the points where it would have been terminated in conventional wireless networks. User
nodes in conventional wireless networks only transmit and receive messages from an Access Point
(AP), and discard any messages not intended for them.
The result is an increase in the volume of network traffic through the links of WMNs. Additionally,
the dense collection of multiple RF signals propagating through a shared wireless medium, contributes
to the situation where the links become saturated at levels below their capacity. The need exists to
examine methods that will improve the utilisation of the shared wireless medium in WMNs.
Network Coding is a coding and decoding technique at the network level of the OSI stack, aimed to
improve the boundaries of saturated links. The technique implies that the bandwidth is simultaneously
shared amongst separate message flows, by combining these flows at common intermediate nodes.
The number of transmissions needed to convey information through the network, is decreased by
Network Coding. The result is in an improvement of the aggregated throughput.
The research approach followed in this dissertation, includes the development of a model that
investigates the aggregated throughput performance of WMNs. The scenario of the model, followed a
typical example of indoors WMN implementations. Therefore, the physical environment representation
of the network elements, included an indoors log–distance path loss channel model, to account for the
different effects such as: power absorption through walls; and shadowing.
Network functionality in the model was represented through a network flow programming problem.
The problem was concerned with determining the optimal amount of flow represented through the
links of the WMN, subject to constraints pertaining to the link capacities and mass balance at each
node. The functional requirements of the model stated that multiple concurrent sessions were to
be represented. This condition implied that the network flow problem had to be a multi–commodity
network flow problem.
Additionally, the model requirements stated that each session of flow should remain on a single path.
This condition implied that the network flow problem had to be an integer programming problem.
Therefore, the network flow programming problem of the model was considered mathematically
equivalent to a multi–commodity integer programming problem. The complexity of multi–commodity
integer programming problems is NP–hard. A heuristic solving method, Simulated Annealing, was implemented to solve the goal function represented by the network flow programming problem of the model.
The findings from this research provide evidence that the implementation of Network Coding in
WMNs, nearly doubles the level of the calculated aggregated throughput values. The magnitude of
this throughput increase, can be further improved by additional manipulation of the network traffic
dispersion. This is achieved by utilising link–state methods, rather than distance vector methods, to
establish paths for the sessions of flow, present in the WMNs. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2012.
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An optimisation approach to improve the throughput in wireless mesh networks through network coding / van der Merwe C.Van der Merwe, Corna January 2011 (has links)
In this study, the effect of implementing Network Coding on the aggregated throughput in Wireless
Mesh Networks, was examined. Wireless Mesh Networks (WMNs) are multiple hop wireless networks,
where routing through any node is possible. The implication of this characteristic, is that messages
flow across the points where it would have been terminated in conventional wireless networks. User
nodes in conventional wireless networks only transmit and receive messages from an Access Point
(AP), and discard any messages not intended for them.
The result is an increase in the volume of network traffic through the links of WMNs. Additionally,
the dense collection of multiple RF signals propagating through a shared wireless medium, contributes
to the situation where the links become saturated at levels below their capacity. The need exists to
examine methods that will improve the utilisation of the shared wireless medium in WMNs.
Network Coding is a coding and decoding technique at the network level of the OSI stack, aimed to
improve the boundaries of saturated links. The technique implies that the bandwidth is simultaneously
shared amongst separate message flows, by combining these flows at common intermediate nodes.
The number of transmissions needed to convey information through the network, is decreased by
Network Coding. The result is in an improvement of the aggregated throughput.
The research approach followed in this dissertation, includes the development of a model that
investigates the aggregated throughput performance of WMNs. The scenario of the model, followed a
typical example of indoors WMN implementations. Therefore, the physical environment representation
of the network elements, included an indoors log–distance path loss channel model, to account for the
different effects such as: power absorption through walls; and shadowing.
Network functionality in the model was represented through a network flow programming problem.
The problem was concerned with determining the optimal amount of flow represented through the
links of the WMN, subject to constraints pertaining to the link capacities and mass balance at each
node. The functional requirements of the model stated that multiple concurrent sessions were to
be represented. This condition implied that the network flow problem had to be a multi–commodity
network flow problem.
Additionally, the model requirements stated that each session of flow should remain on a single path.
This condition implied that the network flow problem had to be an integer programming problem.
Therefore, the network flow programming problem of the model was considered mathematically
equivalent to a multi–commodity integer programming problem. The complexity of multi–commodity
integer programming problems is NP–hard. A heuristic solving method, Simulated Annealing, was implemented to solve the goal function represented by the network flow programming problem of the model.
The findings from this research provide evidence that the implementation of Network Coding in
WMNs, nearly doubles the level of the calculated aggregated throughput values. The magnitude of
this throughput increase, can be further improved by additional manipulation of the network traffic
dispersion. This is achieved by utilising link–state methods, rather than distance vector methods, to
establish paths for the sessions of flow, present in the WMNs. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2012.
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