This master’s thesis is focused on the design of a functional reliable computer network for primary school. The master ‘s thesis analyses the current state of the communication infrastructure of the primary school and the own solution is implemented based on this analysis. Part of the solution deals with implementation of an application for distance education and the basic setup of the school computer server. The master ‘s thesis contains the design of cable routing routes, selection of active elements, Gantt chart of the project and economic evaluation of the whole project.

This thesis explores the possibilities of implementation of methods for data acquisition in wireless access point MikroTik while using virtualized OpenWRT system. First part of the paper contains short introduction into device’s features and extention of the features by virtualizing the operation system. Design and implementation of the scripts for average load of interfaces data acquisition is in the second part of the paper. The next part deals with the transmission of the gathered data and implementation of the proposed programs in C language. The last part of the paper covers the implementation of a complete program to collect, send and receive data with the option of parameters configuration, and automatic acquisition of the configuration.

The focus of this thesis work is to evaluate the RSS (Received Signal Strength) Performance of the University of Gävle (HiG) based on IEEE 802.11 standards both indoor and outdoor. Authors investigated the issues of deploying access points for wireless local area networks in the library-2nd floor, building 99-4th floor and outdoor university campus. By using the program VisiWave Site Survey, Global Position System (GPS) and RSS sensor to analysis the received signal strength, throughput and radio map. The influence of the building material and distance for the signal strength and the throughput are done by investigating indoor environment. The results of investigation suggest that most parts of library-2nd floor and building 99-4th floor possess at least a good RSS performance. However, minority parts of these places have a poor RSS performance, and the new resolution of Access Points’ (AP) deployment for these poor-RSS-performance parts is provided. For the outdoor campus part, the RSS in the area which near the walls of building is satisfactory (Received Signal Strength Indication (RSSI) between -79.8 dBm and -57 dBm), however in the centre of outdoor campus the RSS is poor. Thus, the evaluation of APs deployment in HiG is achieved.

With the proliferation of mobile devices and the advance of audio/video coding technologies, there is an increasing demand to provide quality-of-service (QoS) guarantees for multimedia applications. A WLAN (wireless local are network) typically consists of an access point (AP) and a finite set of mobile stations. Since the AP is generally more powerful and less physical constraint than mobile stations, it is of great interest to consider the use of sectorized multi-beam antennas at the AP to boost the network throughput by exploiting the benefit of spatial reuse. IEEE 802.11 is current the de facto standard for WLANs. However, if we directly apply 802.11 to the WLAN with multi-beam AP without any modification, we will encounter many challenging problems. Although existing solutions modify the 802.11 DCF (distributed coordination function) to solve these problems, yet DCF does not provide any QoS support. On the basis of 802.11e HCCA (hybrid channel control access), in this thesis, we propose a novel MAC protocol, named MPCF (multi-beam AP-assisted point coordination function), which is not only backward compatible with DCF, but also supports QoS functionalities, including non-reversal prioritization, time-bounded reservation, admission control, and cross-layer rate adaptation for multimedia streaming. Simulation results show that, in terms of throughput, frame delay dropped rate, and energy throughput, MPCF significantly outperforms existing protocols even in imperfect beam-forming and mobility environments.

Novel and low-cost antennas suitable for WLAN access points are presented. The operating bandwidths of the proposed antennas can cover the 2.4/5.2/5.8 GHz WLAN bands, and the antenna gain is larger than 2 and 4 dBi in the 2.4 and 5 GHz bands; respectively. Besides, they can also generate the good omnidirectional radiation patterns in the azimuthal plane. Dipole antenna, folded dipole antenna, monopole antenna and circularly polarized antenna has been applied in the proposed designs, and good antenna performance has been obtained.

Šio darbo objektas – išmaniųjų telefonų pastovaus ryšio išlaikymas tarp WiFi adapterių. Dabartiniu momentu yra sukurta daug prieigos taškų paieškos sistemų, tačiau šios sistemos „nemoka“ automatiškai susirasti bei prisijungti prie tinkamiausio prieigos taško. Taip pat egzistuojančios sistemos ieškodamos prieigos taškų išeikvoja daug išmaniojo telefono energetinių resursų. Darbe įvardijami pagrindiniai egzistuojančių sistemų trūkumai ir analizuojamos tobulinimo galimybės panaudojant miglotąją logiką. Pirmojoje darbo dalyje aprašoma tyrimo sritis, objektas bei remiantis literatūros analize atskleidžiamas, per esamas bevielio interneto prieigos taškų paieškos sistemų problemas, temos aktualumas. Antroji dalis apima komponentų projektavimą bei programavimą. Projektavimui naudojama UML, Visio ir FuzzyTech įrankiai. Šioje dalyje yra pavaizduotos komponentų klasių, įvykių bei sekų diagramos, pateikta duomenų bazės schema bei miglotųjų įverčių diagramos. Šioje darbo dalyje yra sukuriama ir pati bevielio interneto prieigos taškų valdymo sistema „HandyWi“. Trečioje darbo dalyje pateikti naujai sukurtos „HandyWi“ sistemos kokybinių tyrimo duomenų palyginimo rezultatai. Pagrysta sukurtos sistemos reikšmė informacinių technologijų srityje. Paskutinėje darbo dalyje pateikta apibendrinta informacija apie sukurtą bevielio interneto prieigos taškų paieškos sistemos funkcionalumą ir išskirtinumą bei tolimesnes jos plėtojimo galimybes. Darbą iliustruoja 41 paveikslas, 9 lentelės ir terminų... [toliau žr. visą tekstą] / The object of this work is to keep stable communication between smart phone and wireless adapter. There are many created access points discovery systems at the moment, but those systems “don’t know” how to discovery and connect to suitable access point. Also existing systems have lost a lot of smart phone battery energy during discovering access points. The main existing systems issues and issues solving abilities by using fuzzy logic are presented at this work. The subject of research, object and subject relevance were detectable through literature analysis and through existing access point discovery systems issues are presented in the first part. The subject of research and object are presented in the first part of this work. Also, subject relevance is presented pursuant to literature analyze of wireless internet access point discovery system. Object components design and programming process are presented in the second part. UML, Visio and Fuzzytech programs are used for designing components. Events, sequence and class diagrams are viewed in this part, also this part contain database schema and fuzzy sets diagrams. The main wireless internet discovery system is created in this part. The system is called “HandyWi”. The “HandyWi” system is comparison with existing system and quality data results are stored in the third part. The conclusions of the work, automatic access point discovery system functionality, oneness and further development abilities are presented in last... [to full text]

Almost all commercially available wireless access devices are special embedded systems with proprietary software that do not allow any modifications. Modifications to these systems are only possible by firmware upgrades released by manufacturers. However, release times of these firmware upgrades are unpredictable, and they are usually for bug-fix purposes rather than being feature and capability improvements. Thus, these devices fail to provide the needed flexibility. Ability to provide timely custom solution that is well integrated into existing network infrastructure is the key factor for a successful wireless access service implementation. In this thesis work, the open source software called AWLP is designed, coded, tested, and released to public as a viable alternative for creating custom wireless access device.

Hultsfreds kommun håller just nu på att föra över sina accesspunkter till ett nytt system som ska hantera dessa. I samband med detta, har de fått önskemål om att lägga upp ett öppet nätverk som personal och elever kan använda till sina privata enheter istället för att ta från sin surfpott. Här har då en undersökning genomförts på Albäcksskolan, där man har kollat på hur detta påverkar accesspunkterna när fler enheter ansluter sig mot dessa. En spectrumanalys har också genomförts för att optimera vilka kanaler som accesspunkterna ska använda. Det öppna nätet har även strypts till 3Mb/s och denna hastighet har utvärderats om den räcker för att utföra de dagliga sysslorna. Till sist har även en täckningskarta tagits fram för att se om täckningsytan går att förbättra. Det blev en väldigt liten ökning i antal enheter och påverkan på accesspunkterna blev därför inte särskilt stor. Det bedöms i nuläget inte att accesspunkterna påverkas så pass mycket att de behöver stärka upp med fler eller bättre accesspunkter. Spectrumanalysen visar konstanta störningar på tre kanaler i en lokal på skolan, där då dessa kanaler tas bort från accesspunkten. Strypningen på det öppna nätet bedömdes vara tillräckligt för att utföra vardaliga sysslor som mail och surf. Täckningen på Albäcksskolan var bra, men några förbättringar kan göras t.ex ta bort överflödiga och flytta till områden med sämre täckningsyta, samt flytta på några för att optimera täckningen ytterligare. / The municipality of Hultsfred is just about to bring over its access points to a new system that will handle these. In associate with this, they have had the desire to set up an open network that staff and students can use for their private devices instead of taking from their own mobile surf. Here has a survey been done at Albäcksskolan, where i have looked at how this affects access points, when more wireless devices join them. A spectrum analysis have also been done to optimize which channels that the access points use. The open network has been limited to 3Mb/s per user and this speed have been evaluated if it is enough for the daily tasks. A map over the wireless coverage area have been developed to see if this can be improved. There was a very small increase in the number of units and the impact on the access points was therefore not particularly high. It is estimated that the access points are not affected to the point so that they need to strengthen with more or better access points. The spectrum analysis shows constant interference on three channels in one place in the school, and as a solution, these channels will not be used there. The speed limitation on the open network is judged to be sufficient for the daily tasks such as e-mail and surfing the net. The wireless coverage  in Albäcksskolan is good, but some improvements can be made, for example remove some of the access points that are overkill and move them to places that need some extra coverage, as well as move some of the access points to optimize coverage further.

Daily usage of Wireless Local Area Networks (WLAN) in business life for specific purposes has became much more critical than before since it is sometimes crucial to have wireless connectivity and seamless roaming around the working environment. In this thesis, steps required in order to design and implement a large scale outdoor IEEE 802.11g WLAN will be shown. This WLAN project has been deployed in north of Sweden and target coverage was an open area consisting of a deep pit mine, connecting roads, workshops, offices, dumps and storage areas. All telecommunications equipment used in this project is from the manufacturer Cisco using centralized solution. The special purpose of this project is to collect and analyze a series of coverage measurement data and correlate this data to predict the coverage area. Linux bash scripting and Gnuplot has been used to analyze coverage data. Finally, WRAP spectrum management and radio planning software has been used in modeling and designing of the whole network.

Designing 802.11 wireless networks includes two major components: selection of access points (APs) in the demand areas and assignment of radio frequencies to each AP. Coverage and capacity are some key issues when placing APs in a demand area. APs need to cover all users. A user is considered covered if the power received from its corresponding AP is greater than a given threshold. Moreover, from a capacity standpoint, APs need to provide certain minimum bandwidth to users located in the coverage area. A major challenge in designing wireless networks is the frequency assignment problem. The 802.11 wireless LANs operate in the unlicensed ISM frequency, and all APs share the same frequency. As a result, as 802.11 APs become widely deployed, they start to interfere with each other and degrade network throughput. In consequence, efficient assignment of channels becomes necessary to avoid and minimize interference. In this work, an optimal AP selection was developed by balancing traffic load. An optimization problem was formulated that minimizes heavy congestion. As a result, APs in wireless LANs will have well distributed traffic loads, which maximize the throughput of the network. The channel assignment algorithm was designed by minimizing channel interference between APs. The optimization algorithm assigns channels in such a way that minimizes co-channel and adjacent channel interference resulting in higher throughput.