Frequency Arrangement For 700 MHz Band Ancans, G.; Bobrovs, V.; Ivanovs, G.
Latvian journal of physics and technical sciences,
02/2015, Volume:
52, Issue:
1
Journal Article
Peer reviewed
Open access
The 694-790 MHz (700 MHz) band was allocated by the 2012 World Radiocommunication Conference (WRC-12) in ITU Region 1 (Europe included), to the mobile service on a co-primary basis with other ...services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT). At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15). In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.
The increased demand of mobile broadband consumers on services in the mobile environment with high data rate and technologically developed mobile broadband communication systems will require more ...spectrum to be available in the future. The new technologies as well as the existing services require frequencies for their development. The authors investigate the available and potential future mobile terrestrial frequency bands - worldwide and in Europe. An insight into the spectrum management is provided, with radio access technologies, methods for more efficient use of mobile frequency bands and frequency cross-border coordination also addressed. It is stressed that the radio frequency spectrum is a limited national resource that will become increasingly precious in the future.
The authors seek best ways to realize chromatic dispersion (CD) compen-sation schemes for differently modulated optical signals in high-speed mixed data rate HDWDM systems. The research is based on ...OptSim 5.1. simulation software, which numerically solves nonlinear Schrödinger equation using the split-step Fourier method. It is shown that the CD compensation scheme is crucial for the performance evaluation in combined HDWM transmission channels. Therefore, a scheme of the type is proposed that is suited best for a very complicated combined fiber optical transmission system. It is also found that asymmetrical CD compensation schemes in pre- and post-compensation modules are the most efficient, allowing the best BER in a channel to be achieved.
Autori ir izpētījuši vispiemērotākās hromatiskās dispersijas (CD) kompen-sācijas shēmas realizāciju ātrdarbīgā HDWDM sistēmā ar dažādi modulētiem optiskajiem signāliem un jauktu pārraides ātrumu. Šī pētījuma pamatā ir OptSim 5.1 simulācijas programmatūras izmantošana, kura, skaitliski, izmantojot sadale-solis Furjē metodi, risina nelineāro Šrēdingera vienādojumu. Darbā ir parādīts, ka hromatiskās dispersijas kompensācijas shēmai ir izšķiroša loma, lai uzlabotu kom-binētas HDWDM sistēmas veiktspēju. Lai palielinātu pārraides ātrumu kanālā četras reizes, ir nepieciešams pielietot dispersijas pārvaldības stratēgiju. Līdz ar to, tika atrasts vispiemērotākais hromatiskās dispersijas kompensācijas risinājums samērā sarežgītas kombinētas šķiedru optikas pārraides sistēmas gadījumā. Tika atklāts, ka asimetrisko hromatiskās dispersijas kompensācijas shēmu izmantošana pirms- un pēc-kompensācijas moduļos ir visefektīvākā un ļauj sasniegt vislabākās iespējamās BER vērtības sistēmas kanālos.
A dense wavelength division multiplexing (DWDM) transmission scheme with two thin-film filters (FWHM bandwidth 100 GHz and 200 GHz) has been realized to evaluate the minimum channel interval needed ...for a satisfactory bit error ratio. For this purpose, detailed research was conducted into the impact of the filters on the optical signal's de-multiplexing in a DWDM system, in which the measurements of eye diagrams and the optical power spectral densities of a received signal were made. From the results of measurements the minimum channel interval has been found for the optical filters that ensures reliable data transmission and higher spectral efficiency of the whole system. It was found that for a DWDM system with a 100 GHz filter a sufficient channel interval is 75 GHz at 10 Gbit/s data transmission speed, which means that its spectral efficiency is increased from 0.1 bit/s/Hz to 0.1333 bit/s/Hz.
Autori ir izveidojuši augsta blīvuma viļņgarumdales blīvēšanas (DWDM) pārraides sistēmu ar diviem plāno kārtiņu filtriem (FWHM joslas platums 100 GHz un 200 GHz), lai novērtētu minimālo kanālu intervālu, pie kura ir pietiekami mazs kļūdu koeficients. Tāpēc veikti detalizēti pētījumi par TFF ietekmi uz optisko signālu de-multipleksēšanu DWDM sistēmās. Novērtējums tika veikts ar uztvertā signāla acu diagrammas un optiskās jaudas spektrālā blīvuma mērījumiem. No mērījumu rezultātiem esam atraduši minimālos kanālu intervālus noteiktiem optiskajiem filtriem, lai nodrošinātu drošu datu pārraidi un līdz ar to palielinātu sistēmas kopējo spektrālo efektivitāti. No rezultātiem redzams, ka DWDM pārraides sistēmai ar 100 GHz TFF pietiekošu veiktspēju nodrošina 75 GHz kanālu intervāls pie 10 Gbit/s datu pārraides ātruma un līdz ar to tiek palielināta spektrālā efektivitāte no 0.1 bit/s/Hz līdz 0.1333 bit/s/Hz.
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