Radio base station(RBS) is the key infrastructure in wireless network and the main product of Ericsson. To improve the efficiency and success rate of RBS maintenance is therefore necessary and beneficial to Ericsson. Augmented reality is a promising solution by annotating computer generated guiding information on real world to enhance the information received during the maintenance. This thesis developed a workable AR application for RBS to evaluate the feasibility and difficulty of applying AR on RBS. Based on Android platform, the application used Vuforia from Qualcomm and Unity as tracking and rendering package respectively. Tracked result was imported to Unity and processed by low pass filters to remove noise. Filtered data was then used to build a distributed world coordinate frame array to cover the entire RBS panel. On this distributed world coordinate frame array, digital contents such as audio, animation were placed and controlled by a task state machine. Drove by the user control in user interface layer, the task state machine provide a flexible task scheduling scheme for task navigation. At last, digital contents and real time video captured by phone camera were synthesized and rendered on the cellphone screen. The result presented a practicable AR solution for RBS maintenance and reveals the advantages and disadvantages of deploying AR technology for RBS. Certain suggestions were also described based on the development.

In this paper, we propose an adaptive and multi-sector-based user clustering algorithm which increases energy efficiency in a cellular network. Adaptive sectoring with dynamically changing sector angles is illustrated with a number of randomly distributed mobile stations. Transmitted power is equally shared by sectors before adaptive user clustering. The sector angles vary from 30 to 360 degrees by merging neighboring sectors and a sector is switched off till the user density exceeds a threshold (Td). The Td value is computed from the total number of users that the cell can accommodate over the area of the cell. The sectors with less than Td density exhibits transmit power which approaches to zero or sleeping state and so that the cumulative power is saved. Simulation results show that an average of 45% to 50% energy can be saved in 10 iterations.

The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant levels in order to achieve green goals. Finally, we introduce the notion of green mobile operator collaboration as a new aspect of the green networking where competitive cellular companies might cooperate together in order to achieve green goals.

Master of Science / Department of Computing and Information Sciences / Gurdip Singh / TinyOS is an open-source component based operating system designed for highly memory constrained wireless embedded sensor network. TinyOS includes interfaces and components for communication management, routing and data acquisition tools to be refined further for custom applications. This project aims at developing a system which detects overlapping paths for data collection in different applications in the network and utilizing that information for efficient data acquisition. This prevents a reconfiguring the entire network of wireless sensor nodes (called motes) for each new application request. The application for initial or first data acquisition request tries to build the tree architecture on motes in the network where each node in the tree knows its immediate parent and children. The application builds the tree routed at the base station for the initial request and each intermediate node sends data to its parent when the data request is made. Each base station can request Light, Temperature and Passive Infrared sensory data from all or a subset of motes present in the system. When a new base station comes and connects to the network through a mote/node in the tree, the system reconfigures only those parts of the tree built in the initial phase which do not overlap with the tree required for the new base station as the root, all the other overlapping parts of the tree are left unchanged. We present experimental result to illustrate the efficiency of the approach.

<p>Denna avhandling handlar om hur befintliga datorinfrastrukturer i t.ex. sjukhus och industrier kan avlasta sensornätverk med energikrävande uppgifter. Vi har forskat på olika aspekter som gör det möjligt att förlänga livslängden på dessa sensornätverk. Avhandlingen presenterar en ny plattform för sensornätverk tillsammans med inledande simuleringar som påvisar att vår plattform ökar livslängden på dessa typer av nätverk.</p><p>Generella sensornätverk är uppbyggda av tätt grupperade, trådlösa, batteridrivna datorer som kan vara så små som en kubikmillimeter. Datorerna kallas för sensorer eller sensornoder eftersom de har en eller flera inbyggda sensorer som känner av sin omgivning. En sensor har till uppgift att samla information från sin omgivning, t.ex. temperatur, fuktighet, vibrationer, hjärtslag eller bilder. Sensorerna skickar sedan informationen till en insamlingsstation någonstans i nätverket.</p><p>I de typer av tillämpningar vi tittar på är det viktigt att minimera energiförbrukningen, så att man maximerar livslängden på sensornätverket. Avhandlingen presenterar en lösning där befintlig datorinfrastruktur fungerar som hjälpdatorer/avlastare till ett sensornätverk. Hjälpdatorerna, eller basstationerna som vi kallar dem i avhandlingen, hanterar energikrävande uppgifter som t.ex. vilken sensor som ska kommunicera med vem samt vid vilken tidpunkt etc. Då kan sensorerna i nätverket fokusera på att utföra sina egna uppgifter tills dess att basstationen säger att uppgifterna ändrats.</p><p>Simuleringar visar att vår plattform kan skicka upp till 97 % mera information till basstationen än en jämförbar plattform med samma energimängd. 88 % av våra sensorer är fortfarande vid liv när den andra plattformens sensorer förbrukat all sin energi.</p><p>Ett exempel på hur dessa typer av nätverk kan användas är att övervaka patienters hälsa och kondition i sjukhus eller sjukhem. Patienter behöver inte ha en fast sängplats där en viss typ av medicinskt övervakningsinstrument finns tillgänglig utan kan placeras där det finns en ledig sängplats. Via trådlös kommunikation skickar sensorerna sedan hälsoinformation som t.ex. hjärtfrekvens och blodtryck till en basstation som i sin tur skickar vidare till ett centralt övervakningsinstrument någonstans på sjukhuset. Övervakningsinstrumentet behandlar informationen och larmar personal med rätt kompetens vid behov. Larmet kan skickas till en mobiltelefon eller en liten handdator som personalen alltid bär med sig. Med larmet skickas även information om var patienten befinner sig och all nödvändig data för att personalen snabbt ska kunna ställa en första diagnos. På detta sätt kan man spara in på antalet specialbyggda sängplatser och slippa dyrbara installationer av medicintekniska utrustningar knutna till en sängplats.</p> / <p>Recent advancements in electronic design, such as low-power circuits, energy efficient wireless communication, and improved energy supply, has enabled the vision of wireless sensor networks to become a reality. Wireless sensor networks typically consist of hundreds up to thousands of collaborating low-cost, battery-driven and wireless sensor nodes with scarce resources. The wireless sensor nodes are typical small physical entities, and usually small as a matchbox but can in extreme cases be no larger than a cubic millimeter.</p><p>In this thesis we present an architecture called AROS that uses existing infrastructure to aid in the management of wireless sensor networks. As an example, the existing infrastructure could be situated in hospitals or industrial buildings. The existing infrastructure can aid in prolonging the lifetime of the wireless sensor network by having "unlimited'' energy, long range radio capacity, and high-speed computers. We enable prolonged lifetime by centralizing some of the energy consuming administrative functionality of wireless sensor networks.</p><p>We show, by simulations, that the AROS architecture is able to prolong the lifetime of the sensor nodes. AROS is compared to a well known cluster based architecture, LEACH. The comparisons show that AROS with static configuration performs at least as well as LEACH in small wireless sensor networks in the size 100x100m, and up to 97 % better in long distance wireless sensor networks in the size of 400x400m. We show that AROS still has got 88 % of its sensor nodes alive when LEACHs' network demises.</p><p>In our simulations we have also studied how dynamic network clustering in AROS, using a TDMA scheduler and non-mobile wireless sensor nodes, affects the amount of data received by a base station. We show that AROS is better than LEACH-C in collecting data to the base station with the same total amount of energy for long distance networks and that AROS performs as well or better than LEACH-C in small wireless sensor networks.</p>

<p>Traffic and Feature SW is a department based in Kista. At this department the main processor software, or MPSW in short, in Ericssons Radio Base Stations is tested prior to integration of new releases. Traffic and Feature SW, also called MPSW in this thesis, works closely with another department of Ericsson called RBS System I&V which tests the same software but for complete RBS nodes. MPSW uses black- and greybox scripted testing in regression suites that are executed on a daily basis. These regression suites are separated into different subsets of functionality that maps to the capabilities of the Radio Base Station software. The authors of this thesis has performed an implementation of automated test cases for a subset of the Radio Base Station software using an automated software tool called QuickCheck. These test cases were successfully integrated into the test framework and were able to find several issues with the main processor software and its subsystems in the Radio Base Station. The commissioner of this thesis have plans to further integrate the QuickCheck tool into the test framework, possibly automating test cases for several subsets of the Radio Base Station software. The authors have therefore analysed and put forth metrics that compares the testing of the Radio Base Station software using QuickCheck with the conventional regression test cases. These metrics covers areas such as the cost related to and the inherent capabilities of QuickCheck. The evaluation of these metrics was performed by the authors to give the commissioner decisive information. These evaluations showed that QuickCheck was able to generate complex message stuctures in complex sequences. QuickCheck was also able to shrink both the content of these messages and the length of the sequences of messages to be able to provide a minimal counterexample when a fault was discovered. The only metric that QuickCheck failed to support was to inherit functionality to support the handling of statistics from executions.</p> / <p>Traffic and Feature SW is a department based in Kista. At this department the main processor software, or MPSW in short, in Ericssons Radio Base Stations is tested prior to integration of new releases. Traffic and Feature SW, also called MPSW in this thesis, works closely with another department of Ericsson called RBS System I&V which tests the same software but for complete RBS nodes. MPSW uses black- and greybox scripted testing in regression suites that are executed on a daily basis. These regression suites are separated into different subsets of functionality that maps to the capabilities of the Radio Base Station software. The authors of this thesis has performed an implementation of automated test cases for a subset of the Radio Base Station software using an automated software tool called QuickCheck. These test cases were successfully integrated into the test framework and were able to find several issues with the main processor software and its subsystems in the Radio Base Station. The commissioner of this thesis have plans to further integrate the QuickCheck tool into the test framework, possibly automating test cases for several subsets of the Radio Base Station software. The authors have therefore analysed and put forth metrics that compares the testing of the Radio Base Station software using QuickCheck with the conventional regression test cases. These metrics covers areas such as the cost related to and the inherent capabilities of QuickCheck. The evaluation of these metrics was performed by the authors to give the commissioner decisive information. These evaluations showed that QuickCheck was able to generate complex message stuctures in complex sequences. QuickCheck was also able to shrink both the content of these messages and the length of the sequences of messages to be able to provide a minimal counterexample when a fault was discovered. The only metric that QuickCheck failed to support was to inherit functionality to support the handling of statistics from executions.</p>

<p>Power-amplifier efficiency is a significant issue for the overall efficiency of most wireless system. Therefore, currently there are different kind of Switched mode power amplifiers are developed which are showing very high efficiency also at higher frequencies but all of these amplifiers are subjected to drive with the constant envelope signals. Whereas, for the increasing demand of high data rate transmissions in wireless communication there are some new modulation schemes are introduced and which are generating no more a constant envelope signal but a high peak to average power signal. Therefore, recently a new technique is proposed called the burst mode operation for operating the switched mode power amplifiers efficiently while driven by a high peak to average power signal.</p><p> </p><p>The purpose of this master thesis work was to review the theory of this burst mode operation and some basic investigations of this theory on switched mode power amplifiers were performed in simulation environments. The amplifiers of class D, inverse D, DE and J are studied. The thesis work was mainly carried out by ADS and partly in MATLAB SIMULINK environment. Since this burst mode operation is a completely new technique therefore a new Harmonic balance simulation setups in ADS and Microwave Office are developed to generate the RF burst signals.</p><p> </p><p>A Class J amplifier based on LDMOS technique is measured by a 16 carrier multi-tone signal having peak to average power ratio of 7 dB and achieved the drain efficiency of 50% with -30 dBc linearity at 946 MHz.</p><p> </p><p> </p>

MU-MIMO theory predicts manyfold capacity gains by leveraging many antennas (e.g. M >> 10) on wireless base stations to serve many users simultaneously through multi-user beamforming (MUBF). However, realizing such a large-scale design is nontrivial, and has yet to be achieved in the real world. We present the design, realization, and evaluation of Argos, the first reported large-scale base station that is capable of serving many (e.g., 10s of) terminals simultaneously through MUBF. Designed with extreme flexibility and scalability in mind, Argos exploits hierarchical and modular design principles, properly partitions baseband processing, and holistically considers real-time requirements of MUBF. To achieve unprecedented scalability, we devise a novel, completely distributed, beamforming technique, as well as an internal calibration procedure to enable implicit beamforming across large arrays. We implement a prototype with 64 antennas, and demonstrate that it can achieve up to 6.7 fold capacity gains while using a mere 1/64th the transmission power.

Power-amplifier efficiency is a significant issue for the overall efficiency of most wireless system. Therefore, currently there are different kind of Switched mode power amplifiers are developed which are showing very high efficiency also at higher frequencies but all of these amplifiers are subjected to drive with the constant envelope signals. Whereas, for the increasing demand of high data rate transmissions in wireless communication there are some new modulation schemes are introduced and which are generating no more a constant envelope signal but a high peak to average power signal. Therefore, recently a new technique is proposed called the burst mode operation for operating the switched mode power amplifiers efficiently while driven by a high peak to average power signal.   The purpose of this master thesis work was to review the theory of this burst mode operation and some basic investigations of this theory on switched mode power amplifiers were performed in simulation environments. The amplifiers of class D, inverse D, DE and J are studied. The thesis work was mainly carried out by ADS and partly in MATLAB SIMULINK environment. Since this burst mode operation is a completely new technique therefore a new Harmonic balance simulation setups in ADS and Microwave Office are developed to generate the RF burst signals.   A Class J amplifier based on LDMOS technique is measured by a 16 carrier multi-tone signal having peak to average power ratio of 7 dB and achieved the drain efficiency of 50% with -30 dBc linearity at 946 MHz.

With the development of IEEE 802.16j multihop relay protocol, the requirement to enhance the network capacity in a wireless network has been met e ectively. In this thesis, we study the capacity enhancement problem for a broadband wireless access network which is achieved by optimal placement of Relay Stations (RSs) along with the presence of a Base Station (BS) and multiple Candidate Positions (CPs). We present a mixed integer programming formulation for the crucial task of RS placement. Weighted objective is also explored to include preferential RS placement. The proposed formulations are solved in a matter of seconds. It is observed that with preferential RS placement, the same demand can be met with 73% fewer RSs with a slight, 6%, decrease in the overall network capacity. Moving forward, the objective is broadened to combine and include joint BS and RS placements for a given network. This model formulation provides better overall capacity than combined capacities of RS placement formulations. Maximin objective is introduced to distribute the excess bandwidth to all subscriber stations (SS) rather than assigning it to only one SS. With this approach, bandwidth allocated to each SS is increases by an average of 35.18%.