SPECTRA: Secure Power Efficient Clustered Topology Routing Algorithm

Wireless Sensor Networks (WSNs) have emerged as one of the hottest fields today due to their low-cost, self-organizing behavior, sensing ability in harsh environments, and their large application scope. One of the most challenging topics in WSNs is security. In some applications it is critical to provide confidentiality and authentication in order to prevent information from being compromised. However, providing key management for confidentiality and authentication is difficult due to the ad hoc nature, intermittent connectivity, and resource limitations of the network. Though traditional public keybased security protocols do exist, they need large memory bandwidths and complex algorithms, and are thus unsuitable for WSNs. Current solutions to the security issue in WSNs were created with only authentication and confidentiality in mind. This is far from optimal, because routing and security are closely correlated. Routing and security are alike because similar steps are taken in order to achieve these functions within a given network. Therefore, security and routing can be combined together in a cross-layer design, reducing the consumption of resources. The focus of this work is on the integration of routing and key management to provide an energy efficient security and routing solution. Towards this goal, this work proposes a security protocol that encompasses the following features: integration of security and routing, dynamic security, robust re-keying, low-complexity, and dual levels of encryption. This work combines all the robust features of current security implementations while adding additional features like dual layer encryption, resulting in an extremely efficient security protocol

Medium access control protocol for visible light communication in vehicular communication networks

Recent achievements in the automotive industry related to lighting apparatuses include the use of LED or laser technology to illuminate the vehicle environment. This advancement resulted in greater energy efficiency and increased safety with selective illumination segments. A secondary effect was creating a new field for researchers in which they can utilize LED fast modulation using the Pulse Width Modulation (PWM) signal. Using LED to encode and transmit data is a relatively new and innovative concept. On the other field, there have been advancements in vehicular communication using radio frequency at 2.4 or 5GHz. This research focuses mainly on a field in which visible light augments or replaces radio frequency communication between vehicles. This research also investigates the effect of asymmetry on network performance using Visible Light Communication (VLC) in vehicular networks. Different types of asymmetry were defined and tested in real-world simulation experiments. Research results showed that asymmetry has a negative influence on network performance, though that effect is not significant. The main focus of the research is to develop a lightweight and new Media Access Control (MAC) protocol for VLC in vehicular networks. To develop a MAC protocol for VLC, special software was developed on top of the existing Network Simulation Environment (NSE). A new VLC MAC protocol for Vehicle to Vehicle (V2V) was benchmarked using a defined set of metrics. The benchmark was conducted as a set of designed simulation experiments against the referent IEEE 802.11b MAC protocol. Both protocols used a newly defined VLC-equipped vehicle model. Each simulation experiment depicted a specific network and traffic situation. The total number of scenarios was eleven. The last set of simulations was conducted in realworld scenarios on the virtual streets of Suffolk, VA, USA. Using defined metrics, the test showed that the new VLC MAC protocol for V2V is better than the referent protocol.Nedavna dostignuća u automobilskoj industriji koja se tiču opreme za osvjetljivanje uključuju korištenje LED ili laserskih rasvjetnih tijela za osvjetljivanje okoline. Ovime se postižu uštede u potrošnji energije kao i povećana sigurnost u prometu. LED rasvjeta je uniformnija od običnih žarulja tako da osvjetljenje bude ravnomjernije i preciznije. Obzirom da su LED selektivne moguće je odabrati segment ceste koji se želi osvijetliti. Upravo ta fleksibilnost LED otvara novi prostor za istraživače gdje mogu koristiti PWM signal za modulaciju podataka. PWM je poseban signal koji ima varijabilnu širinu pulsa na izlazu. Istraživači i znanstvenici mogu koristiti LED za kodiranje i prijenos podataka između automobila. Prednosti korištenja komunikacije u vidljivom dijelu elektro-magnetskog spektra (eng.VLC) je u činjenici da taj segment nije zaštićen licencama te je otvoren za slobodno korištenje. Osim toga, vidljivo, neintenzivno svjetlo nema biološki negativnih posljedica. Kod korištenja PWM signala za modulaciju, postojeći izlaz svjetla i njegova funkcija (osvjetljivanja ceste) nisu narušeni. Ljudsko oko ne može detektirati oscilacije tako visoke frekvencije (oko 5 kHz) S druge strane, komponente koje mogu primiti poslani signal su foto diode ili kamere. Kamere su već prisutne na modernom vozilu u obliku prednje kamere ili stražnje kamere za pomoć pri parkiranju. U svakom slučaju, tehnologija je već prisutna na modernom vozilu. Na drugom području, znanstvenici rade na komunikaciji između vozila koristeći radio valove niže frekvencije 2.4 ili 5 GHz. Komunikacija između automobila je predmet standardizacije i mnoge zemlje već propisuju pravila za obaveznu ugradnju opreme za takav oblik komunikacije. Prednost takvog koncepta je razmjena podatka; od onih za zabavu pa do kritičnih i sigurnosnih podataka npr. informacija o nadolazećem mjestu gdje se dogodila prometna nesreća. Ovo istraživanje se fokusira na proširenje ili zamjenu radio komunikacije sa komunikacijom koristeći vidljivi dio spektra (npr. LED i kamere). Jedan od glavnih nedostataka takvog koncepta je ne postojanje adekvatnog i specijaliziranog protokola za kontrolu pristupa mediju (eng. MAC). Drugi problem je nepoznati efekt asimetrije u VLC komunikaciji na performanse mrežne komunikacija. Ovo istraživanje je prepoznalo i klasificiralo različite tipove asimetrije. Svaki tip je testiran u sklopu simulacijskog eksperimenta u stvarnim scenarijima. Pokazalo se je da asimetrija negativno utječe na mrežne performanse, međutim taj efekt nije značajan jer uzrokuje manje od 0.5 % neuspješno poslanih poruka. Glavni fokus istraživanja je razvoj novog i pojednostavljenog MAC protokola za VLC komunikaciju između automobila. Kako bi se razvio novi MAC protokol nad VLC tehnologijom u prometnim mrežama, bilo je nužno napraviti i novu razvojnu okolinu koja se bazira na postojećim mrežnim simulatorima. Novi VLCMAC protokol za komunikaciju između automobila je testiran koristeći definirani set metrika. Testovi su napravljeni u obliku simulacijskih eksperimenata u kojima su uspored¯ivane performanse novog i referentnog protokola. Referentni protokol, u ovom istraživanju je IEEE 802.11b MAC protokol. U sklopu ovog rada definiran je i model vozila opremljen VLC tehnologijom. U simulacijskim eksperimentima je korišten isti model vozila za oba protokola. Za potrebe istraživanja je definirano jedanaest simulacijskih eksperimenata, svaki od njih opisuje specifične situacije u mrežnim komunikacijama kao i u prometu. Završni simulacijski scenariji uključuju okolinu iz stvarnosti, mreža ulica grada Suffolka, SAD. Osim stvarnih ulica, vozila su se kretala i razmjenjivala podatke koristeći mrežnu komunikaciju na kompletnom ISO/OSI mrežnom stogu sa zamijenjenim MAC podslojem. Razvojna okolina uključuje preciznu provjeru fizičkih karakteristika na razini putanje zrake svjetlosti. Ova preciznost je bila nužna kako bi simulacije bile što vjerodostojnije stvarnim sustavima. Obzirom da se radi o mnogo kalkulacija, obično računalo nije dostatno za izvođenje simulacijskih eksperimenata; zbog toga su se eksperimenti izvodili na klasteru računala Sveučilišta u Zagrebu. Koristeći definirane metrike, istraživanje je pokazalo kako je novi VLC MAC protokol za komunikaciju između automobila bolji od referentnog protokola.

A survey on network simulators in three-dimensional wireless ad hoc and sensor networks

© 2016 The Author(s). As steady research in wireless ad hoc and sensor networks is going on, performance evaluation through relevant network simulator becomes indispensable procedure to demonstrate superiority to comparative schemes and suitability in most literatures. Thus, it is very important to establish credibility of simulation results by investigating merits and limitations of each simulator prior to selection. Based on this motivation, in this article, we present a comprehensive survey on current network simulators for new emerging research area, three-dimensional wireless ad hoc and sensor networks which is represented by airborne ad hoc networks and underwater sensor networks by reviewing major existing simulators as well as presenting their main features in several aspects. In addition, we address the outstanding mobility models which are main components in simulation study for self-organizing ad hoc networks. Finally, open research issues and research challenges are discussed and presented

Secure and Efficient Connectionless Multicast Scheme for Wireless Sensor Network using IBE

Despite much research effort key distribution in Wireless Sensor Networks (WSNs) still remains an open problem. As sensor networks edge closer towards wide-spread deployment, security issues become a central concern. The characteristic of WSNs such as power limitations, computation capability and storage resources make the development of efficient security scheme a great challenge especially for multicast applications. In connectionless multicast, the source explicitly encodes the list of destinations in the connectionless header and then sends the data packet to a router. These connectionless multicast protocols like xcast [51] in MANET and uCast (Unified Connectionless Multicast) [1] in WSNs are designed for small networks. They do not keep any state information relevant to ongoing multicast deliveries at intermediate nodes. All secure multicast scheme are designed for connection originated multicast are based on group creation and management making. This design makes it inapplicable to be applied for connectionless multicast because it does not create groups. This means that there is no secure connectionless multicast scheme designed for WSNs till now. This thesis presents a secure and efficient connectionless multicast scheme in WSNs using identity based encryption (IBE). In proposed solution, each node in the network can request a secure communication with a group of node from a base station. The base station will be responsible for creating and sending the session key. Only nodes in the multicast group will receive and use the session key to establish a secure communication between them

Simulation of basic multi-hop broadcast techniques in vehicular Ad-Hoc networks using veins simulator

Research of Broadcast Techniques in Vehicular Ad-Hoc networks using the VEINS simulatorThis project presents to the reader an incursion into the world of smart cities and vehicles, intelligent transport systems, and vehicular ad-hoc networks (VANETs). They are conceptually analyzed, studied in terms of requirements, framework, architecture, applications and standardization. The main objective of this project is the simulation of basic techniques of message dissemination in VANETs, this project shows a brief description of broadcast dissemination techniques. Also, it is necessary to analyze simulation of VANETs. For this reason, it presents a brief description of mobility generators, network simulators and VANETs simulators paying attention to the open source ones. The main focus is set on the VEINS simulation framework, due to its high performance results and a bidirectional coupling between the network and the traffic simulators. From that point, the project is aimed at analyzing the basic paradigms of VEINS components (OMNeT++, SUMO and the TraCI module) and providing a study on their features. Three techniques are simulated (Flooding, Counter and Probability schemes) in two different scenarios (urban and highway), the simulation results are shown focused on the amount of retransmitting nodes, percentage of reached nodes, amount of packets sent, average packet delay, and percentage of packets received. Finally, a detailed manual is presented to the reader. This manual shows how to install the VEINS simulator and its components in both Windows and Linux systems. In addition, it shows how to create a scenario from an extracted map from OpenStreetMap

Improving Multicast Communications Over Wireless Mesh Networks

In wireless mesh networks (WMNs) the traditional approach to shortest path tree based multicasting is to cater for the needs of the poorest performingnode i.e. the maximum permitted multicast line rate is limited to the lowest line rate used by the individual Child nodes on a branch. In general, this meansfixing the line rate to its minimum value and fixing the transmit power to its maximum permitted value. This simplistic approach of applying a single multicast rate for all nodes in the multicast group results in a sub-optimal trade-off between the mean network throughput and coverage area that does not allow for high bandwidth multimedia applications to be supported. By relaxing this constraint and allowing multiple line rates to be used, the mean network throughput can be improved. This thesis presents two methods that aim to increase the mean network throughput through the use of multiple line rates by the forwarding nodes. This is achieved by identifying the Child nodes responsible for reducing the multicast group rate. The first method identifies specific locations for the placement of relay nodes which allows for higher multicast branch line rates to be used. The second method uses a power control algorithm to tune the transmit power to allow for higher multicast branch line rates. The use of power control also helps to reduce the interference caused to neighbouring nodes.Through extensive computer simulation it can be shown that these two methods can lead to a four-fold gain in the mean network throughput undertypical WMN operating conditions compared with the single line rate case