Starting with this issue of LUCE , we are launching the new column Letters to the Experts : it is a space dedicated to readers , where they can share ideas and comments and ask questions about light and its various and wide-ranging fields of application . In this section , we will publish some questions posed by you , readers , and the corresponding answers by experts from the different realities of the lighting world ( designers , professors , researchers , managers , entrepreneurs , etc .). In this way we would like to give space to our readers , and establish a direct relationship with them , thus ensuring an ever greater and more fruitful interaction so that we can provide a concrete answer to all your professional needs and clarify any uncertainties .
Letters to the Experts
For reasons of space , only a certain number of questions or comments will be published , chosen by the editorial staff and the editorial board , from those most relevant to the topics of each issue of the magazine or of greatest interest / curiosity , while all others will be answered privately by our experts .
The letters should be sent to redazione @ rivistaluce . it
Question asked by Andrea Tumiati , master ’ s student in Civil Engineering at the University of Perugia > What is Li-Fi and what are the concrete applications of this technology that we hear more and more about today ? Replay by : Elisa Belloni , researcher of Electrical Systems for Energy at the University of Perugia > Li-Fi ( Light Fidelity ) is the new wireless data transmission technology that uses LED light modulation to transmit information in a fast , secure and sustainable way . The innovation lies in the fact that light waves can be used instead of the radio waves of classic Wi-Fi systems , and that LED technology allows a modulation of intensity that varies so quickly that it cannot be perceived ( on the other hand , the frequency and amplitude of the wave do not vary , and consequently there is no electromagnetic interference ), which was impossible to achieve using the old sources . In fact , the visible light spectrum is 10,000 times larger than the radio spectrum , and can reach a theoretical maximum data rate of 10 Gbit / s indoors . It should be remembered that indoor LED lighting reaches a maximum intensity of 500 lux ( or slightly more ), which is thus modest and easily affected by natural light interference , while the IEEE standard ( https :// ieeexplore . ieee . org / document / 6163585 ) calls for a maximum of 260 kbit / s outdoors . In reality , the term Li-Fi is a sort of commercial communication “ sticker ” and consequently it is preferable to use the acronym VLC ( Visible Light Communication ). It should also be pointed out that in addition to the VLC there is the FSO ( Free Space Optics ) made with laser beams , which are very fast and travel long distances ( always within the limits of optical visibility ). The definition Li-Fi can lead to misunderstandings because some companies “ sell ” as Li-Fi even infrared systems that , in terms of definition , are not optical radiations . Unlike Wi-Fi communication , which is linked to the generation of electromagnetic fields that limit or even rule out its use in particular environments , VLC offers a viable alternative by allowing effective data transmission indoors without the emission of radio waves . The downside is that this technology is designed to be used at a distance of less than 4 metres , and if there is no direct line of sight to the emitter , the connection is lost . To date , some companies in the sector have already introduced application solutions : for instance , there are indoor geolocation apps that use LED light modulation to define a user ’ s location in an extremely accurate way . In addition , a number of installations have been made in museums , ensuring , for example , that visitors can access information about the various exhibits directly on their smartphones through a specially developed App .
Question asked by Fabio P ., Designer - Electrical Systems Design Studio at Venice > The DNSH ( Do No Significant Harm ) principle “ requires that measures taken under the NRRPs ( National Recovery and Resilience Plan ), do no significant harm to the environment ”; what does this imply for street lighting design ? Replay by : Carlos Alberto Loscalzo , CEO of Signify Italy , Greece and Israel > On the Italiadomani . gov . it website , in the section dedicated to the DNSH Principle , the DNSH Operational Handbook ( Version October 2022 ) is available , whose Sheet 28 is dedicated to “ Terrestrial Connections and Street Lighting ” and details the requirements for street lighting , if the measure falls under an Investment for which a substantial contribution has been defined ( Regime 1 ) or no substantial contribution is envisaged ( Regime 2 ). The Guide also provides the Correlation Matrix between Investments or Reforms and Fact Sheets to enable immediate correspondence between the Measures covered in the NRRP and the Fact Sheets prepared for each individual topic . Each Investment under the NRRP is associated with one or more Technical Data Sheets in which the regulatory references , DNSH constraints , and verification elements are given . It is also essential to consider that the indication of
Regime 1 applies to the main activity , for which a substantial contribution has been declared in the DNSH template ( see Climate Change Mitigation Objective Self-Assessment Sheets for each investment ). Any ancillary measures will have to comply with Regime 2 .
Question asked by Margherita Suss , lighting designer , owner of GMS Studio Associato , professor at the MLD Master Lighting design , Department of Architecture and Design at the Sapienza University of Rome > What impact does the digital transition have on the public lighting service ? Replay by : Nicoletta Gozo , coordinator of the PELL Project and Enea ’ s SmartItaly Goal Project > A transition is the moment of passage and evolution from a “ state ” to another ; in other words , it is a moment where the assuredness and awareness of wanting to promote and achieve a transformation allows those involved to adopt all the changes necessary to bring it about . When focusing on cities , we must consider that the current technological landscape , which is offering Public Administration appealing innovative scenarios and trends , positions them on the way of transition towards urban models and ideals whose horizons aim to make them more sustainable and resilient , or “ intelligent ”. Even if they are defined as “ intelligent ”, or framed in the outdated concept of smart city , cities become like that only when they are redesigned and managed in the “ resemblance ” of the specific urban and territorial context of which they are an expression , and of those who , in that precise historical moment , manage them and live in them . They are cities that know , evaluate and confront each other in order to equip themselves with management , redevelopment and innovative processes that , in addition to being calibrated to their actual needs , reduce the environmental impact of economic and technological progress , aim and prepare themselves to be more sustainable and resilient , and are not projecting themselves towards the ideal of a city , but towards the ideal city , the one that each citizen would like to live in .
LETTERS TO THE EXPERTS / LUCE 344 19