978 research outputs found
Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms
The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications
Spatial spectrum reuse in heterogeneous wireless networks: interference management and access control
Διαχρονικά, η κυρίαρχη σχεδιαστική επιλογή για την βελτίωση της φασματικής
απόδοσης των ασύρματων δικτύων κινητών επικοινωνιών είναι η χωρική
επαναχρησιμοποίηση φάσματος, η δυνατότητα δηλαδή να επαναχρησιμοποιείται το
ίδιο κομμάτι φάσματος πολλές φορές στο χώρο με την προϋπόθεση ότι διατηρούνται
χαμηλά τα επίπεδα των παρεμβολών. Στα σύγχρονα δίκτυα κινητών επικοινωνιών
μελετώνται δύο νέοι τρόποι χωρικής επαναχρησιμοποίησης φάσματος: α) η ανάπτυξη
φεμτοκυψελών (femtocells), η ανάπτυξη δηλαδή μικρών κυψελών για εξυπηρέτηση
κυρίως εσωτερικών χώρων στην ευρύτερη περιοχή κάλυψης μία κύριας κυψέλης, και
β) η ενεργοποίηση επικοινωνιών συσκευής-σε-συσκευή (Device-to-Device – D2D),
απευθείας δηλαδή επικοινωνιών χωρίς την διαμεσολάβηση του σταθμού βάσης της
κυψέλης. Σκοπός της παρούσας διατριβής είναι να μελετηθούν και να
αντιμετωπιστούν οι προκλήσεις που προκύπτουν από την εισαγωγή φεμτοκυψελών και
την υιοθέτηση επικοινωνιών συσκευής-σε-συσκευή σε κυψελωτά δίκτυα
προτυποποιημένα από την 3GPP (3rd Generation Partnership Project). Πιο
συγκεκριμένα, μελετώνται τα προβλήματα της διαχείρισης του φάσματος και των
παρεμβολών, καθώς και θέματα πρόσβασης στο φάσμα για Long Term Evolution (LTE)
και LTE-Advanced (LTE-A) δίκτυα με φεμτοκυψέλες και με επικοινωνίες συσκευής-σε-
συσκευή. Για το σκοπό αυτό, αρχικά μελετήθηκαν τα LTE/LTE-A κυψελωτά δίκτυα ως
προς το φυσικό επίπεδο, την αρχιτεκτονική και τις παρεμβολές, αποτυπώνοντας και
την τρέχουσα κατάσταση στο τομέα της προτυποποίησης των φεμτοκυψελών και των
επικοινωνιών συσκευής-σε-συσκευή. Ακολούθησε μια συγκριτική μελέτη μηχανισμών
διαχείρισης παρεμβολών σε κανάλια ελέγχου ενός LTE/LTE-A δικτύου με
φεμτοκυψέλες και ένας καινοτόμος μηχανισμός ελέγχου ισχύος για μεταδόσεις
φεμτοκυψελών, βασισμένος στην ποιότητα εμπειρίας στο τελικό χρήστη. Η δουλειά
αυτή άνοιξε νέους ερευνητικούς ορίζοντες, όπου το επίπεδο ικανοποίησης του
τελικού χρήστη παίζει ενεργό ρόλο στη διαχείριση του δικτύου και την παροχή των
υπηρεσιών. Παρόλα αυτά, η περεταίρω μελέτη προς την κατεύθυνση αυτή είναι εκτός
του σκοπού της παρούσας διατριβής. Στην συνέχεια, το κύριο βάρος της μελέτης
μεταφέρθηκε στο πρόβλημα της διαχείρισης του φάσματος και των παρεμβολών στο
πολύ πιο δυναμικό περιβάλλον ενός κυψελωτού δικτύου όπου επιτρέπονται οι
επικοινωνίες συσκευής-σε-συσκευή. Σε πρώτη φάση, θεωρήθηκε ένα σύνολο από ζεύγη
συσκευών που επικοινωνούν μεταξύ τους με επικοινωνίες συσκευής-σε-συσκευή και
προτάθηκε ένας μηχανισμός συλλογής πληροφορίας παρεμβολών και ένα σχήμα
ανάθεσης πόρων βασισμένο στη θεωρία γράφων. Το κύριο αποτέλεσμα της μελέτης
αυτής ήταν πως αν και υψηλά επίπεδα χωρικής επαναχρησιμοποίησης μπορούν να
επιτευχθούν, η συλλογή και η επεξεργασία πληροφορίας παρεμβολών είναι ένα
πολύπλοκο πρόβλημα το οποίο απαιτεί και επιπλέον πόρους σηματοδοσίας. Έτσι,
προτάθηκε και αναλύθηκε μίας λύση βασισμένη στον ανταγωνισμό. Πρακτικά οι
χρήστες των επικοινωνιών συσκευής-σε-συσκευή εφαρμόζουν ένα σχήμα ανταγωνισμού
όμοιο με αυτό που χρησιμοποιείται στα δίκτυα WiFi (Wireless Fidelity),
προσαρμοσμένο όμως στο φυσικό επίπεδο των LTE/LTE-A δικτύων. Μαθηματική ανάλυση
του σχήματος έδειξε ισχυρή εξάρτηση των επιδόσεων από το πλήθος των χρηστών που
ανταγωνίζονται για το φάσμα. Σε μια προσπάθεια περιορισμού του πλήθους των
ανταγωνιζόμενων χρηστών μόνο σε αυτούς που βρίσκονται σε γειτνίαση, και άρα
μονό σε αυτούς που η άμεση επικοινωνία τους είναι εφικτή, μελετήθηκε το
πρόβλημα της ανίχνευσης γειτονικής συσκευής. Με βάση τις τρέχουσες προδιαγραφές
της 3GPP, για την επίλυση του προβλήματος ανίχνευσης γειτονικής συσκευής, μία
συσκευή είτε ανακοινώνει με μετάδοση περιοδικών μηνυμάτων την παρουσία της σε
μια συγκεκριμένη περιοχή, είτε αιτείται από κάποια συγκεκριμένη συσκευή
πληροφορία ανίχνευσης. Υιοθετώντας τη δεύτερη περίπτωση, προτάθηκαν βελτιώσεις
στο LTE/LTE-A δίκτυο πρόσβασης ώστε να επιτρέπεται η ανάθεση φάσματος για
μεταδόσεις ανίχνευσης γειτονικών συσκευών. Παράλληλα, δεδομένου ότι και για τις
μεταδόσεις αυτές απαιτείται η κατανάλωση φάσματος, σχεδιάστηκε και αξιολογήθηκε
μία λύση βασισμένη στη χωρική επαναχρησιμοποίηση φάσματος. Το βασικό συμπέρασμα
ήταν ότι λόγω των χαμηλών απαιτήσεων ποιότητας των μηνυμάτων ανίχνευσης, κάτω
από ορισμένες συνθήκες πυκνότητας του δικτύου, μπορεί να επιτραπεί η χωρική
επαναχρησιμοποίηση του κυψελωτού φάσματος για μεταδόσεις ανίχνευσης συσκευής.Historically, the spatial spectrum reuse has been the most efficient approach
for improving cellular system capacity. Based on this observation, the 3rd
Generation Partnership Project (3GPP) has proposed new spatial spectrum reuse
schemes, towards fulfilling the International Mobile
Telecommunications-Advanced (IMT-Advanced) requirements for the 4G networks. In
this direction, a major shift is realized from wide-range cells with high
transmit power (macrocells) to low-power small-sized cells (femtocells), while
a lot of effort is allocated to the spatial spectrum reuse by enabling
Device-to-Device (D2D) communications, i.e., direct communications in a
cellular network, without the intervention of the base station. The scope of
this thesis is to deal with challenges arising from the introduction of
femtocells and D2D communications in cellular networks standardized by 3GPP
Release 8 and beyond, i.e., Long Term Evolution (LTE) and LTE-Advanced (LTE-A).
More specifically, for the case of femtocells, the interference management
problem is studied, while for the D2D communications the radio resource
management and the spectrum access challenges are addressed. First, a
comprehensive description of the physical layer and architecture of the
LTE/LTE-A networks is provided, and the current standardization efforts for the
introduction of femtocells and D2D communications are described. Subsequently,
different control channel interference management schemes for
femtocell-overlaid LTE/LTE-A networks are studied, while an innovative power
control scheme for the femtocell downlink transmissions is proposed, utilizing
the end user’s quality of experience. This work brings to the surface new
research challenges, where the end user’s satisfaction level plays an active
role in network management and service provisioning. However, the further
investigation of these challenges is out of this thesis’ scope. Considering the
much more dynamic environment defined by the D2D communications in a cellular
network, the major research effort is then shifted to the resource and
interference management problem for D2D communications. Assuming a predefined
set of D2D pairs in a cellular network, an interference information collection
mechanism and a D2D resource allocation scheme, based on the graph-coloring
theory, are proposed. Evaluation results showed that even high spatial spectrum
reuse levels can be achieved, the interference collection and processing
problem is quite complex, while additional signaling is needed. Taking this
into account, a contention-based approach is proposed. Under this approach, the
D2D devices compete for accessing the spectrum following a procedure similar
with that used in WiFi (Wireless Fidelity) networks. Performance analysis shows
that the efficiency of the proposed scheme depends on the number of competing
devices. Towards restricting the number of competing devices, only to those
that are in proximity and, thus, in valid positions for D2D communication, the
device discovery problem is studied. According to the 3GPP standardization
efforts, the solution of the device discovery problem requires frequent
transmission of discovery signals from each device, either announcing its
presence in a specific area, or requesting discovery information from a target
device. Adopting the second option, enhancements in the 3GPP standardized
access network are proposed, enabling a resource request / allocation procedure
for device discovery transmissions. In parallel, a spatial spectrum reuse
scheme is designed and evaluated, as an effort to reduce the consumption of
radio resources for discovery transmissions. Analytical and simulation results
show that, under certain conditions for the network density, a number of
discovery transmissions can be enabled in a multi-cellular network even if no
interference information is available
Investigation of Afghanistan network infrastructure for cyber security
06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Anahtar Kelimeler: Siber güvenlik, siber saldırılar, siber savaşlar, güvenlik açığı, gizlilik, bütünlük, ağ altyapısı, iletişim ve bilgi sistemleri. Global endüstriler büyük ölçüde bilgi ve veri güvenliğine yatırım yapıyor. Sanal iletişim zamanında, herhangi bir topolojisinde, öncelikle geçerlik ve güvenliği garanti altına almalı. Aksi takdirde bu tür iletişim karmaşık sorunlara ve kaynakların ağlar üzerinde zarar görmesine neden olur. Halbuki iletişim sistemleri savunmasızdır, Ülkenin bilgi bütünlüğüne, gizliliğine ve kullanılabilirliğine güvenmesi, siber güvenliğinin yetersizliğinden tam tersidir. Aslında, iletişim sistemleri veya internet öncelikle odaklı veya insan zihnindeki güvenlikle tasarlanmamıştır. Diğer bir deyişle, çok sayıda ağ bileşeninin koordinasyonu, öncelikle hava-arayüzü üzerinden kurulan veya ağ üzerinden önceden tanımlanmış protokoller altında fiziksel olarak entegre edilmiş güvenli bir bağlantıya ihtiyaç duyar. Ayrıca, bir hükümetin gerçekleştirme sorumluluğundan biri, siber ortamda ya da gerçekçi saldırı ve tehditlerle mücadele etmek için bir caydırma ekibi ya da teşkilatı oluşturmaktır. Modern iletişim sistemlerinde, siber saldırılar casusluk açısından gittikçe artmaktadır ve bilgi sistemlerine ciddi zarar vermek suretiyle siber alanın geleceğinde büyük bir sorun çıkarmaktadır. Öte yandan, Afganistan hükümeti, herhangi bir dışa bağımlı siber saldırılara karşı iyi tanımlanmış bir stratejiye sahip değilken, casusluktan sorumlu olan ve Afganistan'daki siber alanda katastrofik sorunlar çıkaran ülkelerden aktarılan değiştirilebilir verilerin büyük bir çoğunluğu bulunmaktadır. Bu sorunlar dikkate alındığında, bu çalışma Afganistan'da siber saldırılar ve siber istismar, bilgi güvenliği ile ilgili zorluklar, siber saldırıların mevcut Afganistan ağ altyapıları üzerindeki etkileri ve analizleri de dahil olmak üzere siber tehditlerle ilgilidir. Siberayla ilgili belirgin ve belirgin olmayan siber saldırılar için bir şekilde çözümün yanı sıra, mevcut ve gelecekteki siber krizin, modellerin ve simülasyon özelliklerinin bu raporun kısmen bir bölümünde analizi tanımlanmıştır. Bununla birlikte, güvenlik açısından Afganistan'ın mevcut siber durumuna, yaygın gelecekteki siber güvenlik ve siber güvenlik zorluklarına ilişkin sorunlar da bu raporda gösterilmektedir.Global industries are investing heavily in information and data security. At the time of virtual communication under any types of topologies, firstly, the validity and security must be guaranteed. Otherwise, such communication cause complex problems and resources damage over the networks. However, communication systems are vulnerable, the nation's reliance on the integrities, confidentialities, and availabilities of information stand in stark contrast to the inadequacy of their cybersecurity. In fact, communication systems or internet was not primarily designed with security in oriented or human minds. On the other word, coordinating of huge numbers of network components, first of all, need to a secure connection, either such connection established via air-interface or integrated physically under predefined protocols over the network. Additionally, one of the accomplishment responsibility of a government is creating a deterrence team or military to combat any types of attack and threat either on cyberspace or on realistic. In modern communication systems cyber-attacks becoming increasingly in terms of espionage, and it would make a big challenge in the future of cyberspace by causing serious damage to information systems. From the other hand, the government of Afghanistan does not have a well-defined strategy against any types of outsider cyberattacks while the huge amount of the exchangeable data transferring from the countries who are in charge of espionage and attempt to make catastrophic problems on Afghanistan's cyberspace. In consideration to these issues, this study concerned in Afghanistan's cyber-threats including cyber-attacks and cyber-exploit, information security challenges, analysis and effects of cyber-attacks on current Afghanistan network infrastructures. Definition of somewhat solution for distinctive and non-distinctive cyber-attacks over cyberspace, as well as the analysis of current and future cyberspace crisis, models and simulations aspect in some partial part of this report, has been also covered. However, current cyberspace status of Afghanistan in term of security, challenges of prevalent future cyber security and cyber security difficulties have also illustrated in this report
Emerging technologies for learning (volume 1)
Collection of 5 articles on emerging technologies and trend
Recommended from our members
Self-organising network management for heterogeneous LTE-advanced networks
This thesis was submitted for the award of Doctor of Philosophy and awarded by Brunel University LondonSince 2004, when the Long Term Evolution (LTE) was first proposed to be publicly available in the year 2009, a plethora of new characteristics, techniques and applications have been constantly enhancing it since its first release, over the past decade. As a result, the research aims for LTE-Advanced (LTE-A) have been released to create a ubiquitous and supportive network for mobile users. The incorporation of heterogeneous networks (HetNets) has been proposed as one of the main enhancements of LTE-A systems over the existing LTE releases, by proposing the deployment of small-cell applications, such as femtocells, to provide more coverage and quality of service (QoS) within the network, whilst also reducing capital expenditure. These principal advantages can be obtained at the cost of new challenges such as inter-cell interference, which occurs when different network applications share the same frequency channel in the network. In this thesis, the main challenges of HetNets in LTE-A platform have been addressed and novel solutions are proposed by using self-organising network (SON) management approaches, which allows the cooperative cellular systems to observe, decide and amend their ongoing operation based on network conditions. The novel SON algorithms are modelled and simulated in OPNET modeler simulation software for the three processes of resource allocation, mobility management and interference coordination in multi-tier macro-femto networks. Different channel allocation methods based on cooperative transmission, frequency reuse and dynamic spectrum access are investigated and a novel SON sub-channel allocation method is proposed based on hybrid fractional frequency reuse (HFFR) scheme to provide dynamic resource allocation between macrocells and femtocells, while avoiding co-tier and cross-tier interference. Mobility management is also addressed as another important issue in HetNets, especially in hand-ins from macrocell to femtocell base stations. The existing research considers a limited number of methods for handover optimisation, such as signal strength and call admission control (CAC) to avoid unnecessary handovers, while our novel SON handover management method implements a comprehensive algorithm that performs sensing process, as well as resource availability and user residence checks to initiate the handover process at the optimal time. In addition to this, the novel femto over macro priority (FoMP) check in this process also gives the femtocell target nodes priority over the congested macrocells in order to improve the QoS at both the network tiers. Inter-cell interference, as the key challenge of HetNets, is also investigated by research on the existing time-domain, frequency-domain and power control methods. A novel SON interference mitigation algorithm is proposed, which is based on enhanced inter-cell interference coordination (eICIC) with power control process. The 3-phase power control algorithm contains signal to interference plus noise ratio (SINR) measurements, channel quality indicator (CQI) mapping and transmission power amendments to avoid the occurrence of interference due to the effects of high transmission power. The results of this research confirm that if heterogeneous systems are backed-up with SON management strategies, not only can improve the network capacity and QoS, but also the new network challenges such as inter-cell interference can also be mitigated in new releases of LTE-A network
Recommended from our members
Radio network management in cognitive LTE-Femtocell Systems
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.There is a strong uptake of femtocell deployment as small cell application
platforms in the upcoming LTE networks. In such two-tier networks of LTEfemtocell
base stations, a large portion of the assigned spectrum is used
sporadically leading to underutilisation of valuable frequency resources.
Novel spectrum access techniques are necessary to solve these current spectrum
inefficiency problems. Therefore, spectrum management solutions should have
the features to improve spectrum access in both temporal and spatial manner.
Cognitive Radio (CR) with the Dynamic Spectrum Access (DSA) is considered
to be the key technology in this research in order to increase the spectrum
efficiency. This is an effective solution to allow a group of Secondary Users
(SUs) to share the radio spectrum initially allocated to the Primary User (PUs) at
no interference.
The core aim of this thesis is to develop new cognitive LTE-femtocell systems
that offer a 4G vision, to facilitate the radio network management in order to
increase the network capacity and further improve spectrum access probabilities.
In this thesis, a new spectrum management model for cognitive radio networks is
considered to enable a seamless integration of multi-access technology with
existing networks. This involves the design of efficient resource allocation
algorithms that are able to respond to the rapid changes in the dynamic wireless
environment and primary users activities. Throughout this thesis a variety of
network upgraded functions are developed using application simulation
scenarios. Therefore, the proposed algorithms, mechanisms, methods, and system
models are not restricted in the considered networks, but rather have a wider
applicability to be used in other technologies.
This thesis mainly investigates three aspects of research issues relating to the
efficient management of cognitive networks: First, novel spectrum resource
management modules are proposed to maximise the spectrum access by rapidly
detecting the available transmission opportunities. Secondly, a developed pilot
power controlling algorithm is introduced to minimise the power consumption by
considering mobile position and application requirements. Also, there is
investigation on the impact of deploying different numbers of femtocell base
stations in LTE domain to identify the optimum cell size for future networks.
Finally, a novel call admission control mechanism for mobility management is
proposed to support seamless handover between LTE and femtocell domains.
This is performed by assigning high speed mobile users to the LTE system to
avoid unnecessary handovers.
The proposed solutions were examined by simulation and numerical analysis to
show the strength of cognitive femtocell deployment for the required
applications. The results show that the new system design based on cognitive
radio configuration enable an efficient resource management in terms of
spectrum allocation, adaptive pilot power control, and mobile handover. The
proposed framework and algorithms offer a novel spectrum management for self organised LTE-femtocell architecture.
Eventually, this research shows that certain architectures fulfilling spectrum
management requirements are implementable in practice and display good
performance in dynamic wireless environments which recommends the
consideration of CR systems in LTE and femtocell networks
Coverage in Multi-Antenna Two-Tier Networks
In two-tier networks -- comprising a conventional cellular network overlaid
with shorter range hotspots (e.g. femtocells, distributed antennas, or wired
relays) -- with universal frequency reuse, the near-far effect from cross-tier
interference creates dead spots where reliable coverage cannot be guaranteed to
users in either tier. Equipping the macrocell and femtocells with multiple
antennas enhances robustness against the near-far problem. This work derives
the maximum number of simultaneously transmitting multiple antenna femtocells
meeting a per-tier outage probability constraint. Coverage dead zones are
presented wherein cross-tier interference bottlenecks cellular and hotspot
coverage. Two operating regimes are shown namely 1) a cellular-limited regime
in which femtocell users experience unacceptable cross-tier interference and 2)
a hotspot-limited regime wherein both femtocell users and cellular users are
limited by hotspot interference. Our analysis accounts for the per-tier
transmit powers, the number of transmit antennas (single antenna transmission
being a special case) and terrestrial propagation such as the Rayleigh fading
and the path loss exponents. Single-user (SU) multiple antenna transmission at
each tier is shown to provide significantly superior coverage and spatial reuse
relative to multiuser (MU) transmission. We propose a decentralized
carrier-sensing approach to regulate femtocell transmission powers based on
their location. Considering a worst-case cell-edge location, simulations using
typical path loss scenarios show that our interference management strategy
provides reliable cellular coverage with about 60 femtocells per cellsite.Comment: 30 Pages, 11 figures, Revised and Resubmitted to IEEE Transactions on
Wireless Communication
Will SDN be part of 5G?
For many, this is no longer a valid question and the case is considered
settled with SDN/NFV (Software Defined Networking/Network Function
Virtualization) providing the inevitable innovation enablers solving many
outstanding management issues regarding 5G. However, given the monumental task
of softwarization of radio access network (RAN) while 5G is just around the
corner and some companies have started unveiling their 5G equipment already,
the concern is very realistic that we may only see some point solutions
involving SDN technology instead of a fully SDN-enabled RAN. This survey paper
identifies all important obstacles in the way and looks at the state of the art
of the relevant solutions. This survey is different from the previous surveys
on SDN-based RAN as it focuses on the salient problems and discusses solutions
proposed within and outside SDN literature. Our main focus is on fronthaul,
backward compatibility, supposedly disruptive nature of SDN deployment,
business cases and monetization of SDN related upgrades, latency of general
purpose processors (GPP), and additional security vulnerabilities,
softwarization brings along to the RAN. We have also provided a summary of the
architectural developments in SDN-based RAN landscape as not all work can be
covered under the focused issues. This paper provides a comprehensive survey on
the state of the art of SDN-based RAN and clearly points out the gaps in the
technology.Comment: 33 pages, 10 figure
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