Wyniki wyszukiwania - Biblioteka Nauki

1

Performance analysis of reactive shortest path and multi-path routing mechanism with load balance

100%

Pham P. P. , Perreau S.

Journal of Telecommunications and Information Technology

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2003

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tom nr 2

38-47

EN

Research on multi-path routing protocols to provide improved throughput and route resilience as compared with single-path routing has been explored in details in the context of wired networks. However, multi-path routing mechanism has not been explored thoroughly in the domain of ad hoc networks. In this paper, we analyze and compare reactive single-path and multi-path routing with load balance mechanisms in ad hoc networks, in terms of overhead, traffic distribution and connection throughput. The results reveals that in comparison with general single-path routing protocol, multi-path routing mechanism creates more overheads but provides better performance in congestion and capacity, provided that the route length is within a certain upper bound which is derivable. The analytical results are further confirmed by simulation.

2

Protokoły routingu w mobilnych sieciach ad hoc

100%

Sosnowski G.

Przegląd Elektrotechniczny

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2008

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tom R. 84, nr 3

146-149

PL

Routing w telekomunikacyjnych sieciach ruchomych ze zmienną topologią jest zagadnieniem trudnym i złożonym. Jednocześnie ma on krytyczne znaczenie dla jakości usług dostarczanych przez sieć warstwom wyższym. W niniejszym artykule przedstawione zostały trzy podstawowe klasy protokołów routingu projektowanych pod kątem zastosowania w ruchomych sieciach ad hoc.

EN

Routing process in mobile multihop ad hoc networks is a difficult and complicated issue. There have been proposed many solutions of the routing protocols, beginning from simple modifications of the Internet protocols, up to complicated cross - layer solutions, that work on hierarchical topology structure of the network. In this article there are discussed both main principles and specific examples for each group of protocols.

3

Autonomous Clustering Scheme for Removing the Effects of Heterogeneous Node Degrees in Ad Hoc Networks

100%

Morita R. , Takano C. , Aida M.

Image Processing & Communications

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2016

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tom Vol. 21, no. 2

43--54

EN

In large scale mobile ad hoc networks (MANETs), it is effective to reduce the load of routing by introducing hierarchical routing, and it is conducted by clustering of nodes. A clustering mechanism based on the diffusion equation is a typical autonomous clustering in MANETs, and gives appropriate clustering if all the node degrees are uniform. However, node degrees in MANETs are heterogeneous in general, the fact causes the difference in the strength of diffusion effect. This difference causes that the position of cluster head tends to be around the boundary of networks and degrade battery efficiency of nodes. In this paper, by introducing an asymmetric diffusion depending on node degree, we propose a new clustering metod independent of heterogeneity of node degrees. We show that the proposed method Has efficient characteristics for battery consumption. In addition, we show the comparison of the proposed method with the conventional method with respect to the efficiency of routing.

4

Badania symulacyjne sieci Ad Hoc z wielodostępem TDMA

100%

Marczak A.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2016

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tom nr 6

532--535, CD

PL

W referacie przedstawiono budowę i działanie protokołu komunikacji sieci Ad Hoc z wielodostępem TDMA. Zaprezentowano wyniki badań symulacyjnych transmisji w sieci Ad Hoc pracującej w oparciu o ten protokół. Symulowana sieć składa się ze stacji bazowych i terminali ruchomych znajdujących się w samochodach, samolotach i na statkach.

EN

The paper presents the design and operation of the TDMA Ad Hoc network communication protocol. The paper presents the results of the simulation research of transmission in the Ad Hoc network operating in accordance with the protocol. The simulated network consists of base stations and mobile terminals, which are located in cars, aircrafts and ships.

5

Hyper-heuristics for power-aware routing protocols

100%

Pilski M. , Seredynski F.

Studia Informatica : systems and information technology

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2008

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tom Vol. 2(11)

37--47

EN

The idea underlying hyper-heuristics is to discover some combination of straightforward heuristics that performs very well across a whole range of problems. In this paper we describe genetic algorithm-based (GA) approach that learns such a heuristic combination for solving energy-efficient routing problem in mobile ad hoc networks (MANETs).

6

Opportunistic routing using prioritized forwarders with retransmission control

100%

Yamazaki T. , Yamamoto R. , Miyoshi T. , Asaka T. , Tanaka Y.

Image Processing & Communications

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2016

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tom Vol. 21, no. 1

55--64

EN

In ad hoc networks, broadcastbased forwarding protocols called opportunistic routing have been proposed. In general backoff-based opportunistic routing protocols, each receiver autonomously makes a forwarding decision using a random back off time based on logical distance. However, each potential forwarder must wait for the expiration of the backoff timer before the packet forwarding. Moreover, they cannot gain forwarding path diversityinsparseenvironments. Inthispaper,we propose a novel forwarder selection method for opportunistic routing. In the proposed method, a terminal called, a prioritized forwarder, and which is selected from among neighbours and can forward packets without using the backoff time. In addition, we integrate a hop-by-hop retransmission control in the proposed method, wchich improvesthe packet transmission success rate in sparse environments. We evaluate the proposed method in comparison with the conventional protocols in computer simulations.

7

Parallel and Distributed Simulation of Ad Hoc Networks

100%

Sikora A. , Niewiadomska-Szynkiewicz E.

Journal of Telecommunications and Information Technology

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2009

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tom nr 3

76-84

EN

Modeling and simulation are traditional methods used to evaluate wireless network design. This paper addresses issues associated with the application of parallel discrete event simulation to mobile ad hoc networks design and analysis. The basic characteristics and major issues pertaining to ad hoc networks modeling and simulation are introduced. The focus is on wireless transmission and mobility models. Particular attention is paid to the MobASim system, a Javabased software environment for parallel and distributed simulation of mobile ad hoc networks. We describe the design, performance and possible applications of presented simulation software.

8

Multiobjective Design of Wireless Ad Hoc Networks: Security, Real-Time and Lifetime

100%

Zdravko K.

Journal of Telecommunications and Information Technology

|

2009

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tom nr 2

13-21

EN

This paper deals with the tradeoffs between security, real-time and lifetime performance. Due to the multihop nature of communication wireless ad hoc networks are very vulnerable to attacks. Malicious nodes included in a routing path may misbehave and organize attacks such as black holes. Scaling the number of hops for a packet delivery we trade off energy efficiency against security and real-time communication. To study the multihop communication we propose a hierarchical communication model. The REWARD (receive, watch, redirect) algorithm for secure routing is employed as a main example for corrective actions. Symmetrical routing is a distinguish feature of protocols such as REWARD and we outline the threshold of conflict between power-efficient partitioning of communication links and symmetrical routing.

9

Comparative Study of Wireless Sensor Networks Energy-Efficient Topologies and Power Save Protocols

100%

Niewiadomska-Szynkiewicz E. , Kwaśniewski P. , Windyga I.

Journal of Telecommunications and Information Technology

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2009

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tom nr 3

68-75

EN

Ad hoc networks are the ultimate technology in wireless communication that allow network nodes to communicate without the need for a fixed infrastructure. The paper addresses issues associated with control of data transmission in wireless sensor networks (WSN) - a popular type of ad hoc networks with stationary nodes. Since the WSN nodes are typically battery equipped, the primary design goal is to optimize the amount of energy used for transmission. The energy conservation techniques and algorithms for computing the optimal transmitting ranges in order to generate a network with desired properties while reducing sensors energy consumption are discussed and compared through simulations. We describe a new clustering based approach that utilizes the periodical coordination to reduce the overall energy usage by the network.

10

Energy Efficient Routing for Multi Hop Ad Hoc Networks with Multiple Access and Adaptive Modulation to Maximise Throughput

100%

Khan D. , Ball P. , Childs G.

Image Processing & Communications

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2012

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tom Vol. 17, no. 1-2

47--59

EN

Wireless ad hoc networks are frequently deployed in strategic applications that require the use of battery powered nodes. A key requirement for these networks is to maximize the time span when all nodes have sufficient battery charge to participate in communication with other nodes. To meet this requirement, this paper describes a routing strategy that seeks to find the best balance between minimizing the power consumption and evenly using all nodes within the network to avoid early exhaustion of individual nodes. The proposed routing scheme is compared to reported schemes using minimum power routing and the results show that the proposed scheme gives a longer time until the first node’s battery energy is depleted with a lower network power consumption than schemes using just energy minimization. Multiple access techniques are discussed and a cost-effective scheme based on available wireless LAN channels and space division multiplexing is proposed. Each path can use one, two or three time slots according to the number of hops in the path. Adaptive modulation is used where the link power budget is sufficient to maintain the throughput per unit time regardless of the number of hops in the path. Simulation results show that the throughput can be significantly improved using adaptive modulation with a small reduction in the time until the first node’s battery energy is depleted.

11

Study on the optimization and performance of TDMA allocation algorithm in ships’ ad hoc networks

100%

Han X. , Li Y. , Liu G.

Polish Maritime Research

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2018

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tom S 2

170--175

EN

This paper analyzes the requirements of the information transmission network of ship integrated condition monitoring system, and proposes a design scheme of ship condition monitoring system based on wireless ad hoc network. The wireless ad hoc network protocol was designed, its networking process was analyzed in detail, and the network transmission performance of the monitoring system was tested. The results proved the feasibility of the system. The above solution can be used for the transmission of ship state information that satisfies the requirements of wireless transmission, and has important theoretical and practical significance. The slot allocation algorithm has been receiving extensive attention as an important part of the TDMA system research. This paper analyzes the summarization and summarization of TDMA time slot assignment algorithms from several aspects such as slot synchronization, existing slot allocation algorithm, and slot assignment model, laying an important foundation for researchers to do further research. In the TDMA system, time is divided into non-overlapping time frames, and the time frames are divided into non-overlapping time slots. Each node in the network performs corresponding operations in each time slot.

12

Simulating capture behaviour in 802.11 radio modems

88%

Ware C. , Wysocki T. A. , Chicharo J.

Journal of Telecommunications and Information Technology

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2001

|

tom nr 3

46-54

EN

Simulation plays an important role in the performance evaluation of MAC protocols. Building simulation models which are able to accurately model physical behaviour is fundamental to the outcome of such techniques. Through both qualitative and quantitative comparison of experimental trace data against simulation results obtained using delay, power, and hybrid capture models, this paper investigates the performance of various packet capture models in the simulation analysis of the 802.11 PHY and MAC layer protocols. We illustrate these models are unable to accurately describe the fairness properties of the experimental data. A new model is proposed, Message Retraining, to describe the operation of an 802.11 receiver. We illustrate that the Message Retraining reception model is able to model the fairness characteristics obtained with an IEEE 802.11 radio modem more accurately than the previous capture models.

13

Localization in wireless sensor networks: Classification and evaluation of techniques

88%

Niewiadomska-Szynkiewicz E.

International Journal of Applied Mathematics and Computer Science

|

2012

|

tom 22

|

nr 2

281-297

EN

Recent advances in technology have enabled the development of low cost, low power and multi functional wireless sensing devices. These devices are networked through setting up a Wireless Sensor Network (WSN). Sensors that form a WSN are expected to be remotely deployed in large numbers and to self-organize to perform distributed sensing and acting tasks. WSNs are growing rapidly in both size and complexity, and it is becoming increasingly difficult to develop and investigate such large and complex systems. In this paper we provide a brief introduction to WSN applications, i.e., properties, limitations and basic issues related to WSN design and development. We focus on an important aspect of the design: accurate localization of devices that form the network. The paper presents an overview of localization strategies and attempts to classify different techniques. A set of properties by which localization systems are evaluated are examined. We then describe a number of existing localization systems, and discuss the results of performance evaluation of some of them through simulation and experiments using a testbed implementation.

14

Adaptive Load Balancing Ad Hoc Routing Scheme Inspired by True Slime Mold

88%

Katada H. , Yamazaki T. , Miyoshi T.

Journal of Telecommunications and Information Technology

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2019

|

tom nr 1

14--22

EN

Engineering neo-biomimetics, i.e. imitation models based on body structures and behavior of living organisms, relied upon to solve complex problems, have been studied in various ﬁelds. In distributed networks, such as ad-hoc networks and wireless sensor networks, the behavior of a variety of true slime molds which are capable of constructing multipath ﬂow networks based on the amount of body, has been studied. Ad hoc networks only consist of mobile terminals (nodes) that can relay packets along an established route. However, link relations and the available bandwidth of the nodes change dynamically due to the mobility of nodes. In addition, the speed of communication between nodes also varies due to node positions and their communication-related quality. Thus, practical use of ad-hoc networks still remains an issue, because it is diﬃcult to establish stable routes under such environments. This study aims to propose an adaptive load balancing routing technique that adaptively diversiﬁes the transmission paths based on the available bandwidth, residual battery life, and the data transmission volume, by applying a mathematical model of slime mold routing, known as the physarum solver. We conﬁrm the eﬀectiveness of its adaptive behavior in dynamic environments using computer simulations.

15

Warunki zapewnienia spójności sieci radiowej

88%

Michalak J. , Bednarczyk W.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2016

|

tom nr 6

503--527, CD

PL

W artykule przedstawiono metodę weryfikacji zapewnienia spójności sieci z zadanym prawdopodobieństwem, która może być stosowana dla każdej wieloelementowej, rozległej sieci radiowej typu Ad-Hoc czy WSN na etapie jej planowania. Odzwierciedleniem rzeczywistego scenariusza, czyli sposobu rozmieszczenia węzłów sieci radiowej w terenie jest dobór odpowiedniej funkcji losowania. Przedstawione wytyczne postępowania zostały opracowane dla sieci radiowej działającej na płaszczyźnie dla zmiennego zasięgu radiowego, liczności węzłów i obszaru działania.

EN

This article presents the verification method for expected connectivity in 2-dimensional networks. The method can be used for any multi-node, wide area or selforganizing network (e.g. WSN, MANET, and VANET) at its planning state. The key step of the verification process is to correctly select the distribution function of nodes as a reflection of a real-world terrain scenario. Depending on the assumed types of input parameters (expected connectivity value and node deployment mode), it is possible to estimate limits for radio range, number of nodes or task area.

16

Multiobjective Approach to Localization in Wireless Sensor Networks

88%

Marks M. , Niewiadomska-Szynkiewicz E.

Journal of Telecommunications and Information Technology

|

2009

|

tom nr 3

59-67

EN

Wireless sensor network localization is a complex problem that can be solved using different types of methods and algorithms. Nowadays, it is a popular research topic. What becomes obvious is that there are several criteria which are essential when we consider wireless sensor networks. Our objective is to determine accurate estimates of nodes location under the constraints for hardware cost, energy consumption and computation capabilities. In this paper the application of stochastic optimization for performing localization of nodes is discussed. We describe two phase scheme that uses a combination of the trilateration method, along with the simulated annealing optimization algorithm. We investigate two variants of our technique, i.e., centralized and distributed. The attention is paid to the convergence of our algorithm for different network topologies and trade-off between its efficiency and localization accuracy.

17

Sieci typu community networks i ich zastosowania

75%

Raif P. , Karcewicz J. , Sachenko A. , Kapczyński A. , Banasik A.

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2008

|

tom z. 45

325-334

PL

W artykule opisano znane rodzaje bezprzewodowych sieci ad-hoc oraz przedstawiono pokrótce ich zastosowania. Przeprowadzono klasyfikację protokołów routingu stosowanych w sieciach tego rodzaju. Przedstawiono zasadę działania protokołu OLSR oraz stanowisko badawcze oraz wnioski z początkowych badań działania protokołu.

EN

The article presents known kinds of wireless ad-hoc computer networks and its applications. Presents classification of routing protocols used in such a networks, specification of OLSR protocol and testhed used in experiments with this protocol.

18

Connectivity conditions for two-dimensional radio network

75%

Michalak J. , Bednarczyk W.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2017

|

tom nr 8-9

1042--1047, CD

EN

One of the prerequisites for information delivery through the radio network is to have an interconnected network, which means at least one communication path from any one node to other nodes. This article presents a connectivity verification method for in 2-dimensional networks. The method can be used for any multi-node, wide area or self-organizing network (e.g. WSN, MANET, and VANET) at its planning stage. The key step of the verification process is correct selection of the nodes distribution function which should be the reflection of real-world terrain scenario. Depending on assumed types of input parameters (an expected connectivity value and a node deployment mode), it is possible to estimate limits for radio range, number of nodes or task area.

PL

Jednym z warunków poprawnego dostarczenia informacji wewnątrz sieci radiowej jest istnienie drogi komunikacyjnej pomiędzy żądnymi węzłami. W artykule przedstawiono metodę oceny spójności w sieciach dwuwymiarowych. Zaproponowana metoda może być stosowana dla dowolnej sieci typu WSN, MANET, VANET itp. Kluczowym krokiem w procesie weryfikacji poprawności działania algorytmu jest wybór funkcji rozkładu węzłów w sposób najbardziej odzwierciedlający warunki rzeczywiste. W zależności od założonych parametrów wejściowych możliwe jest oszacowanie minimalnej liczby węzłów niezbędnej dla zapewnienia spójności w określonym obszarze zadań.

19

Symulator do oceny parametrów transmisji w bezprzewodowych sieciach czujnikowych AD-HOC

75%

Paczesny D. , Paczesny T. , Weremczuk J. , Jachowicz R.

Elektronika : konstrukcje, technologie, zastosowania

|

2008

|

tom Vol. 49, nr 6

139-141

PL

Artykuł przedstawia możliwości wykorzystania specjalnie opracowanego przez autorów symulatora sieci bezprzewodowych (AW-SeNS-Ad Hoc Wireless Sensor Networks Simulator) w badaniach nad sieciami czujnikowymi pracującymi w modelu ad-hoc. Dzięki samoorganizacji sieci ad-hoc i zdolności do przesyłania pakietów między węzłami, można wyobrazić sobie zupełnie nowe aplikacje przeznaczone dla medycyny, wojska czy monitorowania środowiska. Przeprowadzenie badań w środowisku aplikacji komputerowej dla specyficznej konfiguracji sieci nazwanej scenariuszem, umożliwia wstępną ocenę teoretycznej funkcjonalności. W artykule zostały przedstawione wyniki symulacji dla przykładowego scenariusza sieci bezprzewodowej ruchomej z fragmentami infrastruktury nieruchomej.

EN

Paper describes usage of specially designed wireless networks simulator (AWSeNS-Ad Hoc Wireless Sensor Networks Simulator in research at ad-hoc sensor networks. Because of self-organising ability of ad-hoc networks and their possibility of routing packets from source to destination, we can imagine new applications in the field of environment monitoring, healthcare or military. Simulation results for specific network configuration called-scenario, enables initial, theoretical estimation of such network functionality, In the paper we present simulation results for example wireless network scenario which includes both mobile and stationary devices.

20

Zastosowanie technologii symulacji do oceny niezawodności sieci typu ad hoc

75%

Yang C. , Zhu. Z. , Huang W. , Yang C.

Eksploatacja i Niezawodność

|

2010

|

tom nr 2

27-30

PL

Ocena niezawodności sieci Ad Hoc przy użyciu technik analitycznych zazwyczaj wymaga wielu założeń. Dlatego też techniki analityczne nie są w stanie uwzględnić wielu czynników stochastycznych charakteryzujących sieci tego typu. Ostatnio symulacja stała się popularnym podejściem do oceny niezawodności sieci Ad Hoc. W niniejszym artykule przedstawiono scenariusze symulacji i omówiono proces projektowania modeli symulacji do oceny niezawodności sieci Ad Hoc. Omówiono również kierunki przyszłych badań.

EN

Reliability evaluation of Ad Hoc networks using analytical techniques usually requires many assumptions. Thus, analytical techniques are unable to consider many stochastic factors of the networks. Simulation has become a popular approach for evaluating the reliability of Ad Hoc networks. This paper introduces simulation scenarios and discusses simulation model design for reliability evaluation of Ad Hoc network. Future research directions are also discussed.