Vim li cas lub neej yav tom ntej thiaj li ci rau WDM thev naus laus zis

Over the years, mankind's understanding of optics has grown - we have mastered the measurement of light, learned how it is produced and how it travels, and as a result built up our understanding of the universe. Fifty years ago, Corning mastered the use of fibre optics, a revolutionary new material, to efficiently transmit light signals over long distances.

Niaj hnub no, qhov tshiab tshaj plaws thiab muaj txiaj ntsig zoo tshaj plaws hauv kev kho qhov muag tso cai rau peb siv cov spectrum ntawm cov wavelengths sib txawv (tsim los ntawm kev tawg ntawm lub teeb). Qhov kev cog lus thev naus laus zis no, hu ua Wavelength Division Multiplexing (WDM), tuaj yeem pab cov neeg ua haujlwm hauv network nyob ua ntej ntawm qhov nkhaus kom tau raws li qhov xav tau ntawm bandwidth.

Imagine light passing through a prism. Through dispersion, light is broken up into various colours and we see a 'little rainbow'. Each colour represents a set of wavelengths, a 'band', and we can separate out different wavelengths of light and operate them independently of other colours. In telecommunications, we use fibre optic cables to transmit information, usually in the form of red or green lasers. In this process we use all the wavelengths within the 'red' or 'green' part of the spectrum, rather than isolating individual wavelengths. Using WDM, we can break up the laser into different wavelengths of light, meaning that the same information that used to occupy the entire 'colour' band in transmission now occupies only a small part of the band. This is why WDM is so promising in terms of increasing network capacity.

We deploy WDM in our networks using "multiplexers" (mux) and "demultiplexers" (demux). Essentially, these products are the equivalent of lenses attached to active devices (lasers), allowing us to manipulate the individual wavelengths within the laser for transmission in the fibre. The transmission of an optical signal (which might represent a phone call, a text message or a video) is then sent through the laser and guided to a specific wavelength by a multiplexer. These signals travel along the fibre together with other transmitted signals of different wavelengths. The multiplexer then receives and processes these transmitted signals, separating the individual signals into a form that can be understood by the transceiver responsible for receiving the information.

Predictably: raws li lub teeb tseem tawg mus rau hauv ntau thiab ntau wavelengths, lub peev xwm ntawm ib tug fiber ntau optical loj hlob heev.

It is important to note that the technology behind WDM is evolving rapidly and we have not yet reached the limit of how many different wavelengths can be transmitted in a single fibre. Coarse Wavelength Division Multiplexing (CWDM) technology is the first generation of WDM technology and can provide up to 18 channels. Dense Wavelength Division Multiplexing (DWDM) is a new iteration of the technology that can provide up to 160 channels. One of the major problems facing today's connected world is the depletion of fibre resources, where the demand for fibre exceeds the amount of fibre available in the network. By using less fibre to transmit and receive multiple services, the development of WDM technology can alleviate the problem of fibre depletion.

Raws li qhov kev thov rau bandwidth txuas ntxiv zuj zus, cov neeg ua haujlwm tab tom saib txhua txoj hauv kev ua kom nrawm rau kev xa tawm lub peev xwm hauv lawv cov tes hauj lwm - seb nws puas yog cov chaw zov me nyuam, hauv nroog cov xov tooj ntawm tes, lossis txawm tias cov kev sib txuas ntev ntev txuas cov nroog, rau npe. ob peb. Tus nqi tseem ceeb ntawm WDM thev naus laus zis yog tias nws tso cai rau cov tswv lag luam kom muaj peev xwm tsis tas yuav nteg cov cables ntxiv. Qhov no yog qhov tseem ceeb tshwj xeeb hauv cov chaw congested uas nws nyuaj rau nrhiav chaw los khiav cov kab txuas ntxiv. Muab qhov kev thov bandwidth cov neeg ua haujlwm tam sim no tab tom ntsib, WDM thev naus laus zis tau nce ntxiv thoob plaws ntiaj teb.

Network deployments are often divided into two categories: greenfield and brownfield deployments. Greenfield deployments refer to new construction - deploying networks on 'green', undeveloped land. Brownfield deployments are usually found in already developed spaces where people have to work with (or around) existing infrastructure. In a greenfield environment, one can easily add additional fibre to the planning process. In a brownfield environment, however, one needs to take into account the existing space constraints and it is not always possible to add additional fibre. Given this, it is extremely challenging to meet the bandwidth requirements of 5G, IoT and smart communities, for example. In this environment, WDM technology is a key component in enabling interconnectivity in the future.

Kev nrawm nrawm ntawm kev tsim kho tshiab hauv WDM thev naus laus zis txhais tau hais tias kev nce qib tshiab tau ua tas li nyob rau hauv cov ntsiab lus ntawm kev nce qib thev naus laus zis nrog rau kev siv. Nyob twj ywm ntawm cov yam ntxwv thiab kev coj ua zoo tshaj plaws cuam tshuam nrog WDM cov khoom yuav yog qhov kev txiav txim ntawm hnub.