611 research outputs found
Reducing the power consumption in wireless access networks: overview and recommendations
Due to growing importance of wireless access and the steeply growing data volumes being transported, the power consumption of wireless access networks will become an important issue in the coming years. This paper presents a model for this power consumption and investigates three base station types: macrocell, microcell, and femtocell base stations. Based on these models, the coverage effectiveness of the three base station types is compared and the influence of some power reducing techniques such as sleep modes and MIMO (Multiple Input Multiple Output) is evaluated
Solutions for wireless internet connectivity in remote and rural areas
Abstract. These days internet connectivity is listed in the basic needs of human habitat. Internet provides inevitable support in getting knowledge, professional and social connectivity, entertainment media, and in running majority of businesses. Human dependency on internet for efficient, proficient and time saving work has increased the demand of internet connectivity worldwide. The global index shows a percentage increase in internet users from 16% to 48% (of the world population) from 2005 to 2019. The users are accessing internet via different media, inclusive of fixed lines and wireless connectivity. In wireless connectivity by 2019, 86% of the world population is using mobile broadband services offered by different telecom operators in different regions. Around 44.7% of the world population lives in rural areas as projected in 2018. Telecom operators are now seeking to cover all urban and rural, segregated, and dense, plateaus and hills, small and big geographical areas for internet connectivity. The majority of challenges faced by operators for deployment of internet connectivity services are in rural areas. Internet users cited in rural areas experience poor coverage and bad quality of service (QoS) in wireless internet access. This thesis covers the rural area internet connectivity challenges, existing deployable solutions against the challenges, and provides example solutions to overcome these challenges, to provide wireless network coverage in rural areas of Finland.
Many of the existing wireless communication services are directly deployable or adjustable to the remote or rural areas almost the same way as for the urban areas. The major challenge is the low annual revenue per unit and segregated population densities of rural areas, which increase the return of investment time of network service providers. There are other challenges like ease of assembly, technology, backhaul connectivity, and electricity discussed in the thesis. The possible wireless network solutions deployable for wide area network regions and local area network regions are presented in this thesis. Thesis presents all emerging wireless technologies like small cell base station, super tower, balloon Loon project, power line Airgig project, satellite Viasat service, fixed wireless internet, and signal booster. Two possible network solutions for wireless network coverage in rural areas of Finland are analysed in the thesis. Huaweiâs RuralStar small cell base station is presented as the first network solution from the viewpoint of network service provider. Hajakaista network services to individual user are presented as the second network solution from the viewpoint of end user. An addition of outdoor router in Hajakaista network architecture is presented as an additional advantage of outdoor Wi-Fi service together with indoor Wi-Fi. The limitations of the network solutions and future work scope are discussed in the discussion part of the thesis.Langattomia tietoliikenneratkaisuja syrjĂ€alueille. TiivistelmĂ€. Nykyisin internetyhteys nĂ€hdÀÀn perustarpeeksi koska se antaa pÀÀsyn tietoon, mahdollistaa ammatilliset ja sosiaaliset yhteydet sekĂ€ toimii viihdevĂ€ylĂ€nĂ€ ja tĂ€rkeĂ€nĂ€ osana liiketoimintaa. TĂ€mĂ€n vuoksi tarve internetyhteydelle on kasvanut maailmanlaajuisesti. Vuonna 2005 maailman ihmisistĂ€ 16 % oli yhteys internettiin ja 2019 48 %. Internetyhteys voidaan saada usealla eri tavalla kuten valokuidulla ja langatonta yhteyttĂ€ kĂ€yttĂ€en. Vuonna 2019 maailman ihmisistĂ€ 86 % kĂ€ytti langatonta tekniikkaa. Vuonna 2018 44,7 % ihmisistĂ€ asui maaseutualueilla. Teleoperaattorit yrittĂ€vĂ€t kattaa kaikki kaupunki- ja maaseutualueet; eristyneet, tasaiset, kukkulaiset, isot ja pienet maantieteelliset alueet. Suurimmat haasteet ovat maaseudulla, jossa ihmiset kokevat huonoa yhteyspeittoa ja yhteyden laatua. TĂ€mĂ€ diplomityö tarkastelee, miten nykyisiĂ€ langattomia jĂ€rjestelmiĂ€ voitaisiin kĂ€yttÀÀ maaseudulla toimivien yhteyksien luomiseksi. Työ esittÀÀ kaksi esimerkkiratkaisua Suomen olosuhteisiin.
Monet nykyisin kaupungeissa kÀytettÀvÀt ratkaisut ovat suoraan tai lÀhes suoraan sovellettavissa maaseudulle. PÀÀhaasteet ovat matala vuosittainen yksikkötuotto ja hajallaan olevat alueet, jotka syyt kasvattavat investoinnin kuoletusaikaa. Muita haasteita ovat asennus, teknologia, siirtoyhteydet (tukiasemasta verkkoon) ja sÀhkön saanti, joita tarkastellaan työssÀ. Mahdollisia langattomia ratkaisuja ovat laajan alueen ja paikalliset ratkaisut, kuten työssÀ tuodaan esille. Työ tarkastelee solukkoverkkoja, supertornia, palloprojekti Loonia, sÀhkölinjoihin pohjautuvaa Airgig-projektia, Viasat-satelliittiratkaisua, kiinteÀÀ solukkoyhteyttÀ ja signaalin passiivista vahvistamista. Työ esittÀÀ kaksi ratkaisumallia Suomen olosuhteisiin. Toinen perustuu Huawein RuralStar-kevyttukiasemaan, jolla voi jatkaa operaattorin verkkoa. Toinen ratkaisu on kuluttajalÀhtöinen ja se perustuu Hajakaista Oy:n ratkaisuun. SiinÀ lisÀtÀÀn Hajakaista Oy:n perusratkaisun eli talon sisÀisen Wi-Fi-verkon rinnalle ulkoinen Wi-Fi-verkko. Ratkaisujen rajoitteita tarkastellaan työn keskusteluosuudessa
Simulation and Emulation Approach for the Performance Evaluation of Adaptive Modulation and Coding Scheme in Mobile WiMAX Network
WiMAX is the IEEE 802.16e standard-based wireless technology, provides Broadband Wireless Access (BWA) for Metropolitan Area Networks (MAN). Being the wireless channels are precious and limited, adapting the appropriate modulation and coding scheme (MCS) for the state of the radio channel leads to an optimal average data rate. The standard supports adaptive modulation and coding (AMC) on the basis of signal to interference noise ratio (SINR) condition of the radio link. This paper made an attempt to study the performance of AMC scheme in Mobile WiMAX network using simulation and emulation methods. Different MCS are adopted by mobile subscriber station (MSS) on the basis of the detected instantaneous SINR. Simulation results demonstrate the impact of modulation and coding scheme on the performance of the system and emulation results defend the simulation results
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Performance measurements and analysis of the existing wireless communication technology in Iraq.
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityIraq may be considered as the largest wireless market in the Gulf region. A key driving factor in the market of wireless communication, it has seen enormous growth in the mobile phone market over the last five years leading to almost 24 million subscribers in 2011. Moreover, there are several technologies and services working in Iraq; three GSM Operators, three CDMA national operators and three CDMA provinces operators. The recent growth in the mobile phone market is based on the Global System for Mobile (GSM) communications and Code Division Multiple Access (CDMA) standards creating the next-generation wireless technologies in the Iraqi Wireless Communication market. One of the essential issues of this research is to investigate the performance of the decreased Quality Of Service (QoS) caused by interferences in the services on GSM/CDMA operators in Iraq. Many issues should be studied and taken into consideration, such as; does the Multi-Coalition Forces cause the interferences, jamming, higher rate of calls drop and false ringing; or are they caused by bad design and planning? Do we need to optimise our network due to the large number of users? All these factors are investigated and the measurements of most service providers and government agencies will be gathered. A detailed analysis was included from the providers with measurements of performance and the reasons for the deterioration of wireless services. The novel contributions of this thesis is the extensive radio measurement campaign over the three mobile an CDMA operator networks and the analysis and recommendations that were drawn to suggest the best approach to improve the QoS of Wireless communication technologies. Awareness of actual reasons behind the deterioration of services will be raised to the Iraqi Government, CMC and the wireless service providers
C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 2: Test Bed Performance Evaluation and Final AeroMACS Recommendations
This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II (this document) describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers
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Optical fiber transmission systems for in-door next generation broadband access network.
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.This thesis investigates the generation and radio-over-fibre (RoF) transport of unlicensed 60 GHz millimetre-wave (mm-wave) frequency band. The investigated benefits of transmission schemes applicable for the mm-wave generation include optical carrier suppression (OCS), optical frequency multiplication (OFM) and remote heterodyne detection (RHD). For the in-door cabling of the mm-wave transmission, a low-cost polymer optical fibre (POF) along with bend-insensitive single mode fibre (BI-SMF) has been investigated for short-range networks. Transporting mm-wave generated signals over POF and BI-SMF cables based on OCS scheme showed results with the highest spectral efficiency and least inter-symbol interference over a 2.5 Gbit/s data delivery. Based on this thesis analysis, OCS simulation of POF showed the most reliable power penalty performance and receiver sensitivity at 30-m whilst the BI-SMF fiber produced equal observations at 150-m and more. In observing the free space links of delivering the RoF signal, the attenuation on the received signal power for both POF and BI-SMF was insignificant but expected, as the simulation assumed complete and total collimation of the light beams onto the aperture of the photodetector. OCS scheme for mm-wave generation and transport was explored based on the cost effectiveness of using one external modulator compared to other generation schemes that utilised more than one external modulator. OFM scheme was simulated to transport LTE and Wi-Fi signals along with 60 GHz RF band through both SMF and MMF-POF/BI-SMF cables. OFM transport scheme produced the highest attenuation on LTE, Wi-Fi and mm-wave signals carrying 100 Mbit/s data as simulated POF lengths increased. The best performance POF length was observed at 10-m. The application of offset launch technique at the coupling of SMF and POF showed insignificant improvement on signal bandwidth. The free space OFM transmission also demonstrated negligible change to the received signal power. This reinforces the attributes of deploying OWC system in an in-door environment. In other investigation, the simulated successful delivery of mm-wave signal using RHD scheme modulated and transported 10 Gbit/s data signal over POF and BI-SMF cables. Additional observed unrecorded result also showed BI-SMF cable maintained a 2% reduction of received power for 450-m fiber cable from 150-m. The attributes to RHD includes its low operating power system application and delivery of localised 60 GHz signal for uplink RoF transmission. The conceptualised design of Gigabit data delivery for indoor customer applications either through POF or BI-SMF cable, transporting various wireless channels has been presented in this thesis for the design of a robust next generation Broadband access network to reinforce the fiber-inside-the-home (FiTH) deployment
Dynamic Capacity Enhancement using a Smart Antenna in Mobile Telecommunications Networks
This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity.
A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide âbroadcast channelâ beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams âfootprintsâ have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system
Properties and performance of the prototype instrument for the Pierre Auger Observatory
Construction of the first stage of the Pierre Auger Observatory has begun. The aim of the Observatory is to collect unprecedented information about cosmic rays above 10^18 eV. The first phase of the project, the construction and operation of a prototype system, known as the engineering array, has now been completed. It has allowed all of the sub-systems that will be used in the full instrument to be tested under field conditions. In this paper, the properties and performance of these sub-systems are described and their success illustrated with descriptions of some of the events recorded thus far.Facultad de Ciencias Exacta
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