Many National regulatory authorities are making measurements of mobile internet access service Quality of Service parameters, but only some of them measure and evaluate signal parameters of the ...network in the Quality of Service (QoS) measurement location. Although measurement of signal parameters is not obligatory for NRAs, it should be considered that signal parameters are important for mobile network operators for finding faults in network installations.Especially important relation between the throughput and signal parameters is in 5G networks in regard to coverage examination, where throughput is directly related to the Signal interference noise ratio (SINR) parameter values reported by the user equipment. In 5G case uplink channel quality of the user equipment can be indicated by SINR, but to test it, relation between other indicators such as reference signal receive power and transmit power of user equipment should be calculated. Relation and dependency between signal parameter values and Quality of Service parameters values should be evaluated from the regulatory perspective, as for choosing the appropriate measurement geographical location, as for further information for the operators, indicating the possible problems in the networks in specific geographical location and suggesting appropriate solution. The research explores the relation between signal parameter values and Quality of Service parameters values under different circumstances and in different frequency bands, defining the dependency between the values of different parameters in LTE mobile networks. The statistical data used in the research has been gathered by making the practical measurements in the different geographical locations in different mobile electronic operators' networks, to ensure, that the results are applicable for different service providers networks, which have different policies and technical equipment. The approach for evaluating the dependency between different parameter values can be applied to practical on site measurements of the 5G networks for different mobile network operators.
In modern world, technology plays a significant role. Upcoming services, demanding a specific level of service quality that should be guaranteed no matter what, will impose obligations to network ...performance and capacity. European strategy for broadband development prescribes a set of quality indicators that networks should correspond. But imposed obligations themselves don't guarantee the persistent level of quality. European initiatives of geographical mapping of broadband access, which are developed in order to monitor the development of internet access services, propose guidance for gathering and representation of estimated QoS parameters at the so-called QoS-1 level, whereas monitoring of actual network performance on QoS-2 level and representation of real and objective internet quality indicators rests undefined. Besides ensuring that quality is described in meaningful and comparable manner the general measurement methodology that suits various purposes should be established. This research is aimed to develop principles of monitoring and objective representation of internet access service quality parameters in specific location on QoS-2 level, as well as to establish joint mechanism to obtain the quality of service data that would be appropriate for different needs. This research is directed to the mobile internet access service.
The 694–790 MHz band (700 MHz) known also as the second digital dividend was allocated to the mobile radiocommunication service on a primary basis in Region 1 and identified to International Mobile ...Telecommunications by the World Radiocommunication Conference 2012 (WRC-12). The designation of mobile service in Europe and other countries of Region 1 in 700 MHz band was obtained after the World Radiocommunication Conference 2015 (WRC-15). Administrations of Region 1 will be able to plan and use these frequencies for mobile networks, including IMT. The goal of this study is to estimate the electromagnetic compatibility of Digital Video Broadcasting – Terrestrial (DVB-T/DVB-T2) and LTE (Long Term Evolution) technology operating both in 700 MHz band. The study assumes frequency division duplex (FDD) channel arrangement of 703–733 MHz (for uplink) and of 758–788 MHz (for downlink).
The model contains two parts: a DVB-T/DVB-T2 system and LTE mobile broadband network. Co-channel scenario is considered in this paper, and possible impact of DVB-T/DVB-T2 on LTE base stations (receivers) is also investigated. The Monte Carlo simulations within SEAMCAT software and the Minimum Coupling Loss (MCL) method are used for interference investigation. The coordination trigger field strength value predetermined by GE06 Agreement is also used in this study. The Monte Carlo method presents more relaxed electromagnetic compatibility scenario in comparison with the MCL method. For SEAMCAT simulations, ITU-R P.1546-5 radio propagation model is used.
The obtained results present the required minimum separation distance between DVB-T/DVB-T2 and LTE networks in the 694–790 MHz in order to provide the necessary performance of LTE mobile network.
To evaluate potential utilization of semiconductor optical amplifiers (SOAs) as a wideband amplification alternative to erbium doped fibre amplifiers (EDFAs) in dense wavelength division multiplexed ...(DWDM) coherent systems, the authors discuss changes in power consumption levels required for a single bit transmission. The research evaluates the power efficiency parameter for WDM transmission systems using both amplification schemes – EDFAs that utilise standard C-band and SOAs assuming 75 nm amplification spectral band. The power efficiency levels have been estimated for five transmission spans with maximal distance of 640 km. The standard 50 GHz channel spacing has been chosen for both system configurations to allocate 100 Gbps dual-polarization quadrature phase shift keying (DP-QPSK) optical signals. The simulation schemes are described along with the critical parameters, derived from the recent relevant studies that should be taken into account considering usage of SOAs as in-line amplifiers.
To ensure that end-users and consumers have access to comprehensive, comparable and user-friendly information regarding the Internet access service quality, it is necessary to implement and regularly ...renew a set of legislative regulatory acts and to provide monitoring of the quality of Internet access services regarding the current European Regulatory Framework. The actual situation regarding the quality of service monitoring solutions in different European countries depends on national regulatory initiatives and public awareness. The service monitoring solutions are implemented using different measurement methodologies and tools. The paper investigates the practical implementations for developing a harmonising approach to quality monitoring in order to obtain objective information on the quality of Internet access services on mobile networks.
Due to potential economic benefits and expected environmental impact, the power consumption issue in wired networks has become a major challenge. Furthermore, continuously increasing global Internet ...traffic demands high spectral efficiency values. As a result, the relationship between spectral efficiency and energy consumption of telecommunication networks has become a popular topic of academic research over the past years, where a critical parameter is power efficiency. The present research contains calculation results that can be used by optical network designers and operators as guidance for developing more power efficient communication networks if the planned system falls within the scope of this paper. The research results are presented as average aggregated traffic curves that provide more flexible data for the systems with different spectrum availability. Further investigations could be needed in order to evaluate the parameters under consideration taking into account particular spectral parameters, e.g., the entire C-band.
Considering the growing demand for broadband of access networks, in the present paper we investigate various modulation formats as a way of increasing the performance of optical transmission systems. ...Non-return-to-zero (NRZ) on-off keying, return-to-zero (RZ) OOK, carrier suppressed RZ (CSRZ) OOK, duobinary (DB), NRZ differential phase shift keying (NRZDPSK), RZ-DPSK and CSRZ-DPSK formats are compared using the maximal achievable reach with bit error rate less than 10
as a criterion. Simulations are performed by using OptSim software tool. It is shown that using the transmission system without dispersion compensation the best results are shown by duobinary and CSRZ-OOK modulation formats, but with the system using dispersion compensating fiber (DCF) the longest transmission distance is achieved by RZ-DPSK modulation format. By investigating the influence of channel spacing for best-performed modulation formats, network reach decrease for transmission systems with DCF fiber has been observed due to channel crosstalk.
Currently, many research topics in the field of optical transmission systems (mostly grounded on novel modulation techniques) are focused on increasing the total data transmission speed of an ...individual optical fiber. An alternative - but equally valid - approach to increasing the data transmission is to decrease the WDM channel spacing to high-dense dimensions while keeping the existing data transmission speed for an exact channel. We have developed an experimental HDWDM transmission system based on the quasi-rectangular optical filter technique. The results indicate that for 2.5 Gbit/s HDWDM transmission the suitable channel interval should be greater than 25 GHz, and for the 10 Gbit/s HDWDM solution - not less than 37.5 GHz between adjacent channels.
Liela daļa no pētījumiem optiskajās pārraides sistēmās koncentrējas uz individuālas optiskās šķiedras pārraides ātruma palielināšanu. Vairākums no šiem pētījumiem ir balstīti uz inovatīvām modulācijas metodēm. Alternatīva, bet ekvivalenta pieeja ir WDM sakaru sistēmas kanālu intervāla samazināšana līdz minimāli atļautajam, saglabājot nemainīgu datu pārraides ātrumu konkrētam kanālam. Publikācijā ir parādīts eksperimentāls HDWDM pārraides sistēmas makets ar kvazi-taisnstūra filtrēšanas tehniku. Mērījumu rezultāti liecina, ka 2,5 Gbit/s HDWDM pārraides sistēmu ir iespējams realizēt ar 25 GHz kanālu intervālu, savukārt, 10 Gbit/s HDWDM pārraides sistēmā kanālu intervāls starp blakus esošajiem kanāliem jāizvēlas ne mazāks kā 37,5 GHz.
Electric field-induced second harmonic (EFISH) generation effect in paraelectric lanthanum doped lead zirconate-titanate ceramics (PLZT) has been utilized in the local oscillator device of nonlinear ...optical heterodyne interferometer. Application of PLZT X/65/35 plates in low frequency rotating electric field as the reference sources of EFISH for interferometric analysis of anisotropy of thin films or surfaces of crystals is proposed. Experimental details and properties of multiphase PLZT EFISH modulator has been discussed.
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