Wyniki wyszukiwania - BazTech

1

Modelowanie wielozakresowej sieci taktycznej z dynamicznym zarządzaniem widmem

Gajewski Piotr, Łopatka Jerzy, Łubkowski Piotr

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2022

|

nr 4

527--530

PL

W artykule przedstawiono rozwiązanie wysokiej jakości symulatora taktycznej sieci mobilnej MAENA. Omówiono zasady budowy modelu sieci z zaawansowanymi technikami efektywnego wykorzystania zasobów widmowych i unikania zakłóceń. Proponowane rozwiązania zostały sprawdzone w heterogenicznych scenariuszach sieciowych. W pracy przedstawiono przykładowe wyniki symulacji w złożonym środowisku propagacyjnym.

EN

The article presents a solution of a high-quality MAENA tactical mobile network simulator. Principles of the network model construction with advanced techniques of efficient use of spectral resources and disturbances avoiding are discussed. The proposed solutions have been tested in heterogeneous network scenarios. The paper presents example simulation results in complex propagation environment.

2

Routing protocols in mobile ad-hoc networks

Mikarić Bratislav, Rančić Dejan, Ilić Slaviša

Przegląd Elektrotechniczny

|

2020

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R. 96, nr 8

106--111

EN

There were more than 8.6 billion mobile devices in the world in the 2019. To be available is imperative in modern society, both in business and in private life. There are mobile networks available on airports, hotels, restaurants, libraries but sometimes we have to make a quick, mobile network on open area for educational campus or military purposes, where there are no mobile operators and public networks such as GSM. A different model of mobile networks is created and called Mobile Ad-hoc Network. The problem of routing is basically the problem of finding the shortest path between nodes. This paper deals with various routing protocols in MANET and shows how to choose the best one for specific purpose.

PL

Na świecie jest ponad 8.6 miliardów bezprzewodowych urządzeń mobilnych I olbrzymia lic\ba sieci. Żeby rozwiązać problemy komunikacyjne trzeba korzystać z metod jak najszybszego I najkrótszego połączenia miedzy węzłami. W artykule analizowano najlepsze sposoby routingu.

3

Ochrona informacji w radiostacjach definiowanych programowo systemu łaczności bezprzewodowej dla użytkowników mobilnych

Wicik Robert, Grzonkowski Marcin, Białas Robert

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2019

|

nr 6

283--286, CD

PL

System łączności bezprzewodowej jest budowany z wykorzystaniem szerokopasmowych radiostacji definiowanych programowo, których zadaniem jest tworzenie ad-hoc sieci szkieletowych IP dla użytkowników poruszających się na pojazdach. System zapewnia ochronę informacji w warstwach transmisji, sieci i komunikacji, gdzie zastosowano mechanizmy kryptograficzne dedykowane na potrzeby budowania różnych domen. Podsystem zarządzania radiostacjami i kryptografią umożliwia planowanie, zarządzanie i zbieranie doświadczeń z misji.

EN

The wireless communication system is built with wide band software defined radios (SDR) in order to create ad-hoc IP network for users moving on vehicles (MANET). This system provides TRANSEC, NETSEC and COMSEC protection with cryptographic mechanisms dedicated to national, allied and coalition needs. The radio and cryptography management subsystem enables planning, management and collecting mission experiences.

4

Reliable Restricted Process Theory

Ghassemi Fatemeh, Fokkink Wan

Fundamenta Informaticae

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2019

|

Vol. 165, nr 1

1--41

EN

Malfunctions of a mobile ad hoc network (MANET) protocol caused by a conceptual mistake in the protocol design, rather than unreliable communication, can often be detected only by considering communication among the nodes in the network to be reliable. In Restricted Broadcast Process Theory, which was developed for the specification and verification of MANET protocols, the communication operator is lossy. Replacing unreliable with reliable communication invalidates existing results for this process theory. We examine the effects of this adaptation on the semantics of the framework with regard to the non-blocking property of communication in MANETs, the notion of behavioral equivalence relation and its axiomatization. To utilize our complete axiomatization for analyzing the correctness of protocols at the syntactic level, we introduce a precongruence relation which abstracts away from a sequence of multi-hop communications, leading to an application-level action preconditioned by a multi-hop constraint over the topology. We illustrate the applicability of our framework through a simple routing protocol. To prove its correctness, we introduce a novel proof process, based on our precongruence relation.

5

Heavy Gas Cloud Boundary Estimation and Tracking using Mobile Sensors

Krzysztoń M., Niewiadomska-Szynkiewicz E.

Journal of Telecommunications and Information Technology

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2016

|

nr 3

38--49

EN

This paper addresses issues concerned with design and managing of monitoring systems comprised of mobile wireless sensing devices (MANETs). The authors focus on self-organizing, cooperative and coherent networks that maintain a continuous communication with a central operator and adopt to changes in an unknown environment to achieve a given goal. The attention is focused on the development of MANET for heavy gas clouds detection and its boundary estimating and tracking. Two strategies for constructing the MANET are described, in which sensors explore the region of interest to detect the gas cloud, create temporary network topology and finally, cover the cloud boundary, and track the moving cloud. The utility and efficiency of the proposed strategies has been justified through simulation experiments.

6

Improved MCBDS for defending against gray hole and black hole attacks in MANETs

Haghighi A., Mizanian K., Mirjalily G.

Advances in Science and Technology. Research Journal

|

2016

|

Vol. 10, nr 30

1--8

EN

Mobile Ad-hoc Networks (MANETs) are widely used nowadays. Because of their characteristics as open media, dynamic topology, being infrastructure-less and lack of centralized monitoring, MANET is vulnerable to a wide range of attacks like blackhole and grayhole. Blackhole and grayhole attacks refer to the attacks that breach the security by performing packet forwarding and routing misbehavior and cause denial of service in MANETs. In this paper we improved our previous work on MCBDS, we reduced false-positive rate more than before and on average it dropped to zero. The proposed method employs Network Simulator-2 (NS-2) to validate the effectiveness under different scenarios. Simulation results show that improved MCBDS has same performance as CBDS in terms of throughput and end-to-end delay and as much as the presence of malicious nodes increased, improved MCBDS performs better than CBDS.

7

Distributed certificate authority in cluster-based manet using multi secret sharing scheme

Azza M, Hacene S B

Advances in Science and Technology. Research Journal

|

2015

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Vol. 9, nr 28

1--9

EN

Providing secure communications in mobile ad hoc networks (MANET) is an important and difficult problem, due to a lack of a key management infrastructure. The authentication is an important security service in (MANETs). To provide a node authentication service we use a fully distributed certificate authorities (FDCA) based on the threshold cryptography. In this paper we propose an efficient and verifiable multi secret sharing scheme in cluster-based MANET with a low computation system. Our scheme is based on the overdetermined linear system equation in Galois fields GF(2r). We have analyzed our scheme based on security and performance criteria, and compared with existing approaches. The efficiency of our proposed schemes was verified and evaluated by simulation. Simulation results show that this approach is scalable.

8

On-demand QoS and Stability Based Multicast Routing in Mobile Ad Hoc Networks

Basarkod P. I., Manvi S. S.

Journal of Telecommunications and Information Technology

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2014

|

nr 3

98--112

EN

Finding a connection path that remains stable for suciently longer period is critical in mobile ad hoc networks due to frequent link breaks. In this paper, an on-demand Quality of Service (QoS) and stability based multicast routing (OQSMR) scheme is proposed, which is an extension of ad hoc on-demand multicast routing protocol (ODMRP) to provide QoS support for real time applications. The scheme works as follows. Each node in the network periodically estimates the parameters, i.e., node and link stability factor, bandwidth availability, and delays. Next step is creation of neighbor stability and QoS database at every node by using estimated parameters. The last sequence is multicast path construction by using, route request and route reply packets, and QoS and stability information, i.e., link/node stability factor, bandwidth and delays in route information cache of nodes, and performing route maintenance in case of node mobility and route failures. The simulation results indicate that proposed OQSMR demonstrates reduction in packet overhead, improvement in Packet Delivery Ratio (PDR), and reduction in end-to-end delays as compared to ODMRP, and Enhanced ODMRP (E-ODMRP).

9

On-demand Bandwidth and Stability Based Unicast Routing in Mobile Adhoc Networks

Basarkod P. I., Manvi S. S.

International Journal of Electronics and Telecommunications

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2014

|

Vol. 60, No. 1

27-39

EN

Characteristics of mobile ad hoc networks (MANETs) such as lack of central coordination, dynamic topology and limited resources pose a challenging problem in quality of service (QoS) routing. Providing an efficient, robust and low overhead QoS unicast route from source to destination is a critical issue. Bandwidth and route stability are the major important QoS parameters for applications where long duration connections are required with stringent bandwidth requirements for multimedia applications. This paper proposes an On-demand Bandwidth and Stability based Unicast Routing scheme (OBSUR) in MANET by adding additional QoS features to existing Dynamic Source Routing (DSR) protocol. The objective of the OBSUR is to provide QoS satisfied, reliable and robust route for communicating nodes. The scheme works in following steps. (1) Each node in the network periodically (small regular intervals) estimates bandwidth availability, node and link stability, buffer availability, and stability factor between nodes. (2) Construction of neighbor stability and QoS database at every node which is used in route establishment process. (3) The unicast path is constructed by using route request and route reply packets with the help of route information cache, and (4) route maintenance in case of node mobility and route failures. Simulation results show that there is an improvement in terms of traffic admission ratio, control overhead, packet delivery ratio, end to end delay and throughput as compared to Route Stability Based QoS Routing (RSQR) in MANETs.

10

HGRP: hybrid grid routing protocol for heterogeneous hierarchical wireless networks

Shen Y., Pei Q., Xu Q., Xi N., Ma J.

Control and Cybernetics

|

2012

|

Vol. 41, no. 2

353-371

EN

The heterogeneous mobile terminals coexist in the next generation wireless networks. The most common routing schemes for mobile ad hoc networks are designed for homogeneous wireless networks. The heterogeneous wireless network routing protocols are needed urgently in many important applications. This paper improves the routing scheme utilizing different capability of terminals and the Hybrid Grid Routing Protocol (HGRP) is proposed. The network is organized in the grid form, that is, the network deployment area is divided into square cells according to the location. Each cell contains one backbone node and several ordinary nodes. This proposed protocol consists of four parts: grid construction, local routing, global routing, and routing correction. Analysis and simulation results indicate that the proposed protocol has the advantages of lower routing cost, lower energy consumption, smaller delay and higher throughput, compared to AODV and ZRP.

11

Metodyka badań protokołów trasowania dla sieci ad-hoc

Malinowski T.

Biuletyn Instytutu Automatyki i Robotyki

|

2012

|

R. 18, nr 33

71-90

PL

W artykule scharakteryzowano, jako przedmiot badań symulacyjnych, protokoły routingu dynamicznego dla sieci ad-hoc. Przedstawiono zasady przygotowania i realizacji eksperymentu symulacyjnego, służącego ocenie wpływu zastosowanego protokołu trasowania na funkcjonowanie sieci ad-hoc. Wyniki badań symulacyjnych, przeprowadzonych zgodnie z proponowanym planem eksperymentu symulacyjnego, pozwalają wskazać preferowany tryb uaktualniania tras w tablicach routingu węzłów sieci mobilnej o określonej wielkości i w zależności od szybkości przemieszczania się węzłów.

EN

This paper describes dynamic routing protocols for ad hoc networks as a matter of simulation. The principles of preparation and implementation of a simulation experiment were presented. An example of the experiment was to illustrate the impact of the used routing protocol on the functioning of ad hoc networks. Results of the simulation will indicate the preferred mode of updating routes in routing tables of the mobile nodes of a certain size network and various speed of nodes.

12

Selfishness detection in mobile ad hoc networks: how dissemination of indirect information turns into strategic issue

Konorski J.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

|

2010

|

T. 18

139-143

EN

For a mobile ad hoc network, the tradeoff between a selfish node's power expense and ill reputation is discussed. Simulation shows that selective drops can be countered by a data-centric, end-to-end ACK-based reputation system that has nodes disseminate equal reputation metrics for all transit nodes on a misbehaving route. Fake recommendations, however, necessitate an additional revocation scheme.

PL

Dla środowiska sieci mobilnej ad hoc przedyskutowano wymienność pomiędzy wydatkiem energetycznym węzła egoistycznego a obniżaniem jego metryki reputacyjnej. Badania symulacyjne wskazują, że atakom polegającym na selektywnym usuwaniu pakietów można przeciwdziałać poprzez datacentryczny system reputacyjny bazujący na potwierdzeniach końcowych, który nakazuje jednakowo uaktualniać metryki reputacyjne dla wszystkich węzłów na źle zachowującej się trasie. Ataki poprzez fałszywe rekomendacje wymagają jednak dodatkowego systemu wycofywania uaktualnień reputacji.

13

Wykorzystanie technik bezprzewodowych w systemach dowodzenia i kierowania

Amanowicz M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2009

|

nr 6

211-215

PL

Dokonano przeglądu dostępnych oraz rozwijających się technik bezprzewodowych z punktu widzenia ich wykorzystania we współczesnych systemach dowodzenia i kierowania. Scharakteryzowano środowisko, w którym są prowadzone współczesne operacje militarne oraz wynikające stąd wymagania wobec infrastruktury telekomunikacyjnej systemu dowodzenia i kierowania środkami walki. Omówiono aktualne wykorzystanie technik bezprzewodowych w systemach militarnych oraz uwarunkowania użycia wybranych rozwiązań stosowanych z powodzeniem w systemach komercyjnych. Podkreślono rolę innowacyjnych koncepcji i technik w zaspokajaniu bieżących i przyszłych potrzeb operacyjnych.

EN

The paper considers the applicability of wireless technologies to the needs of command and control (C2) systems. It gives a brief description of the operational environment of the modern military missions and identifies the basic requirements on communication infrastructure of the C2 system. The paper describes existing technologies that are used in the military environment and considers emerging wireless technologies evolving in the commercial world that are in scope of military interest. It also depicts the influence of disruptive concepts and technologies in fulfilling the current and future operational needs.

14

Towards realistic mobility models for mobile ad hoc and sensor networks

Martyna J.

Studia Informatica

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2008

|

Vol. 29, nr 4B

147-157

EN

In this paper, we investigate the impact of mobility on the performance of multi-hop wireless ad hoc and sensor networks. We introduced some models of mobility in these networks and studied their behavior in realistic situations. It concerns the basic relationship between link length and message transmission. Additionally, we take into consideration the probability of successful transmission in an interference limited channel when fading is modeled as Rayleigha block fading. Our mobility models are verified by an accurate description and simulation of the behavior of mobile sensor and ad hoc networks.

PL

W pracy zbadano wpływ ruchu na wydajność wieloetapowych bezprzewodowych sieci ad hoc oraz sensorowych. Wprowadzono pewne modele ruchu w tych sieciach, a także zbadano ich zachowanie w realistycznych sytuacjach. Artykuł rozważa podstawowe zależności pomiędzy długością łącza radiowego a transmisją kominikatu. Rozważono w nim prawdopodobieństwo poprawnej transmisji w przypadku krótkookresowych zaników z funkcją gęstości prawdopodobieństwa obwiedni sygnału opisywanego rozkładem Rayleigha. Dla weryfikacji modeli ruchu przeprowadzono badania symulacyjne zachowania ruchomych sieci sensorowych i ad hoc.

15

Quality of service support, security and OSPF interconnection in a MANET using OLSR

Adjih C., Minet P., Muhlethaler P., Baccelli E., Plesse T.

Journal of Telecommunications and Information Technology

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2008

|

nr 2

70-76

EN

The MANET networks are of prime interest for military networks. One of the proeminent routing protocols for MANET is OLSR, and indeed, OLSR has been used in many evaluations and experiments of MANETs. As OLSR is on its way to standardization, there are still a number of extensions that are useful and sometimes necessary for practical use of OLSR networks: such extensions are quality of service support, security, and OSPF interconnection. In this paper, we present the architecture, design, specifications and implementations that we made to integrate these features in a military test-bed. This test-bed is a real MANET comprising 18 nodes. These nodes communicate by radio and use the IEEE 802.11b MAC protocol. The OLSR routing protocol updates the routing table used by the IP protocol to forward packets.

16

A static test-bed for the evaluation and optimization of multihop wireless network protocols

Bongartz H. H.-J., Bachran T.

Journal of Telecommunications and Information Technology

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2008

|

nr 2

62-69

EN

We investigate the performance of multicast transmissions in a simple stationary wireless multihop ad hoc network test-bed. We compare several methods for MANET multicast using implementations for the protocols MOLSR, SMOLSR and SMF with an approach that uses explicit multicast and link-layer retries for reliable multicast. Results from the test-bed are compared with simulation results. We find that implementing a combination of explicit multicast with a retry mechanism gives the most promising results in test-bed and simulation compared with other approaches.

17

Byzantine Agreement & Fault Diagnosis Agreement in Dynamic Ad-Hoc Environment

Cheng C-F., Wang S-C., Liang T.

Fundamenta Informaticae

|

2008

|

Vol. 89, nr 2-3

161-187

EN

Since wireless communication and mobile computing are becomingmore and more ubiquitous, the reliability and fault tolerance of the Mobile Ad-hoc Network (MANET) has become an important topic. In order to provide a reliable environment, a mechanism that allows a set of nodes to reach a common agreement, even in the presence of faulty nodes, is needed. Therefore, the Byzantine Agreement (BA) problem has drawn attention of more researchers. Traditionally, the BA problem was focused on wired networks. We know that the physical topology of a wired network is static, but the physical topology of an MANET is dynamic. Thus, previous BA protocols are not applicable in an MANET. In this paper, a new protocol is proposed to solve the BA problem with malicious faulty components in dynamic MANET. Furthermore, we also propose a new Fault Diagnosis Agreement (FDA) protocol to detect/locate faulty components to provide a highly reliable environment. From the performance perspective, the proposed protocols use the minimum number of message exchanges and can tolerate/detect/locate the maximum number of faulty nodes allowed in the dynamic network.

18

Metryki reputacji w sieciach mobilnych ad hoc

Konorski J., Orlikowski R.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

|

2007

|

T. 14

769-776

PL

Dla przeciwdziałania niepoprawnym zachowaniom węzłów w mobilnych sieciach ad hoc projektuje się systemy reputacyjne, ściśle powiązane z mechanizmami routingu i przekazywania pakietów. W pracy przedyskutowano zasady wyznaczania wartości reputacji w kilku znanych systemach, zwracając uwagę na konieczność zapewnienia wiarygodności reputacji. Efekty różnych metod wyznaczania reputacji zilustrowano przy pomocy prostych ekspe-rymentów symulacyjnych.

EN

Reputation systems, tightly coupled with routing and forwarding mechanisms, are being deployed in mobile ad hoc networks to counteract faulty, malicious, and noncooperative behaviour of nodes. In this paper we discuss methods of determination of reputation values in a few existing reputation systems, pointing to the need for trust-worthy reputation values. The impact of various methods is illustrated by way of simple simulation experiments.

19

Self-adaptive MANET : a centralized approach

Basu S. S., Chaudhuri A.

Foundations of Computing and Decision Sciences

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2004

|

Vol. 29, No. 4

271-286

EN

In this paper we propose a centralized adaptive movement algorithm for mobile nodes in a MANET to maintain neighbourhood topology. A MANET (Mobile ad-hoc network) operates without a fixed infrastructure and is also mobile because of the nature of the applications they are proposed for. In our approach each node is enabled with a GPS receiver. A node in the network is identified as the leader in the beginning. Each node identifies their one hop neighbours before starting movement and broadcast the information to the leader. All nodes also transmit their position information obtained through GPS receiver to the leader in a predefined periodic interval. By analyzing the positions, the leader realizes the movement trend and neighbourhood breakage possibilities within the network and directs the nodes to control their movement to ensure the topology retention. The impact of this concept is the elimination of routing algorithm during message transfer between the nodes and thus increases in message transfer rate.

20

LPAR: an adaptive routing strategy for MANETs

Abolhasan M., Wysocki T. A., Dutkiewicz E.

Journal of Telecommunications and Information Technology

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2003

|

nr 2

28-37

EN

This paper presents a new global positioning system (GPS)-based routing protocol, called location-based point-to-point adaptive routing (LPAR) for mobile ad hoc networks. This protocol utilises a 3-state route discovery strategy in a point-to-point manner to reduce routing overhead while maximising throughput in medium to large mobile ad hoc networks. In LPAR, data transmission is adaptable to changing network conditions. This is achieved by using a primary and a secondary data forwarding strategy to transfer data from the source to the destination when the condition of the route is changed during data transmission. A simulation study is performed to compare the performance of LPAR with a number of different exisiting routing algorithms. Our results indicate that LPAR produces less overhead than other simulated routing strategies, while maintains high levels of throughput.