在咖啡廳、公園、機場等公共場所，WiFi是個很不靠譜的東西，時斷時續的信號經常令人抓狂。不過全球最大的照明公司卻認為，它已經掌握了能夠替代WiFi的技術。

這家公司名叫Signify，中文名字叫“昕諾飛”，也就是以前的飛利浦照明。昕諾飛這幾年致力于研發一種新型寬帶技術，它能夠利用商用LED燈具的光波來傳輸網絡信息，而不是像WiFi那樣使用無線電波。根據最近公布的一項協議，昕諾飛將與全球最大電信運營商之一的沃達豐（Vodafone）展開合作，以使這項技術早日變成現實。

對昕諾飛以及照明行業的其他企業來說，研發可見光無線通信技術不僅僅是為了開拓新市場。自從LED燈泡成為主流產品以來，各大照明廠商成功延續了一百多年的商業模式受到了極大沖擊，因此，可見光通信技術不僅關乎照明企業的發展問題，甚至關乎它們的生存。

帶寬有保證

可見光無線通信技術又叫“LiFi”，其工作原理是在照明設備上添加一個信號解調器，用來控制照明設備發出高速閃爍信號，這些閃爍信號雖然用人眼查覺不到，但是平板電腦、筆記本電腦、智能手機、調制解調器、路由器等設備卻能夠順利接收到——總之，它有些像光纖技術，只不過它只有“光”，而沒有“纖”。

昕諾飛的LiFi系統部門全球負責人米歇爾·格爾梅指出：“我永遠不會說LiFi將取代WiFi。但是在LiFi技術下，高網速和高帶寬是可以保證的。”

而WiFi技術的提供商則很少有底氣給出這種保證，因為WiFi使用的是無線電波，而無線電波會受到各種信號源的干擾。首先，WiFi信號之間會互相沖突，在人員稠密的公共場所，許多個WiFi信號源難免會彼此干擾，由此導致的信號接收困難經常令人抓狂。

雖然WiFi技術的理論帶寬很高，但由于信號干擾問題，以及WiFi技術與生俱來的一些制約因素，經常會導致網絡傳輸中的延遲，進而導致網速下降。換句話說，不管WiFi的帶寬率是多少兆每秒，實際上它的網速經常是很低的。

有的時候，WiFi還會與一些敏感的醫療設備或生產設備的信號發生沖突，這就是為什么有的醫院或生產車間里要禁用WiFi。

造成這些問題的根源，是由于無線電的頻譜沒有充足的空間讓各個WiFi網絡彼此隔離。即便全部無線電頻譜都可以用于WiFi技術，它的可用空間與光譜相比仍然相形見絀。因為光譜比無線電頻譜至少大出1000到10000倍。

LiFi的另一個優勢，是它一般來說比WiFi更安全。無線電信號可以穿透窗戶和墻壁，一旦WiFi網絡的安全性做得不好，就很容易被外部不法分子侵入。而要想連入LiFi網絡，就必須處在光源能夠直接照射的范圍內，這就大大降低了網絡從外部被入侵的可能性。

正因為LiFi技術的巨大的潛能，沃達豐的德國分公司從今年10月1日起與昕諾飛展開了合作。今年，沃達豐已經在德國的幾個城市開通了5G網絡。下一步，沃達豐很可能會將LiFi技術用于其5G網絡的布建。

LiFi的缺點

從媒體報道上看，LiFi的前景似乎很美好。不過就像其他所有新興技術一樣，任何事物都是有缺點的。

首先，目前我們使用的手機等智能設備是不能直接接收LiFi信號的，除非插入一個特制的USB“接收器”。各大電腦和手機廠商從很早以前就開始在設備里安裝WiFi接收器了，但還沒有哪家廠商在智能設備里內置LiFi接收器。

目前，LiFi接收器的芯片技術是不存在障礙的。蘋果和安卓陣營之所以都沒有安裝LiFi接收器，一定程度上是由于標準之爭尚未塵埃落定。目前，昕諾飛支持的技術方案有國際電信聯盟（ITU）的背書，而其他照明廠商支持的另一方案則有美國電氣電子工程師學會（IEEE）的支持。另外，在LiFi接收器被大規模采用之前，它的成本必然很高，會讓很多手機廠商望而卻步。

使用USB接收器當然會給用戶帶來不便。另一個問題則是目前已經安裝的商用LiFi網絡太少。昕諾飛目前只試點安裝了60多個LiFi信號源，每個都是一次性和試驗性的，而且都沒有立即產生大規模的、企業級的影響。

最近的一次是在德國漢堡的人民公園足球場。上個月，該球場的媒體室安裝了一臺LiFi設備，這樣記者們就可以通過LiFi網絡發稿了。（不過同時，該媒體室也有一個WiFi網絡作為“備胎”。）

從用戶的評論看，這項技術應該還有改進的空間。

漢堡體育俱樂部的區域組織和基礎設施負責人丹尼爾·諾爾特表示：“我們沒有遇到任何重大的技術問題，但它是一項很新的技術……似乎仍然有優化的潛力，特別是在用戶友好度方面。”

諾爾特表示，大多數記者仍然選擇使用WiFi網絡，不過也有少數幾人使用了LiFi網絡，并且對這項技術“似乎很滿意”。俱樂部在LiFi的指定連接區域放了幾個信號接收器。不過問題是，使用蘋果設備的記者必須加載額外的軟件來驅動這些設備。（Windows用戶則不需要。）

LiFi如何融入5G時代？

有一個問題很重要，但是沃達豐和昕諾飛目前都沒有給出明確答案，那就是LiFi將如何融入即將到來的5G時代——以及5G是否會讓LiFi淪為邊緣技術。

最近幾個月，各大網絡運營商紛紛開始推出5G網絡。5G也是目前全球最新最快的移動網絡。

眾所周知，5G信號對墻和窗戶的穿透能力比較差，這是它的弱點之一，這也給LiFi技術留下了一個機會。不過各大運營商都在想方設法解決室內5G服務的問題——比如AT&T、T-Mobile、韓國電信，以及昕諾飛的合作伙伴沃達豐等等。AT&T還表示，很快它就將在德州阿靈頓市的AT&T體育館提供室內5G服務。

與此同時，愛立信和高通等硬件公司也力求通過各種方案來解決這個問題，其中呼聲較高的是一種名叫“分布式天線系統”的方案。就在10月下旬，英特爾還與康寧公司展開合作，嘗試通過軟件等手段，推動5G網絡的室內應用。

“這項技術還處于早期階段。”格爾梅認為，LiFi可以在室內實現極高的5G網速。另外，LiFi技術還可以用于無人駕駛領域，幫助無人駕駛汽車實現相互通訊，使汽車更好地做出制動或者轉向等指令。另外，LiFi在機器對機器通訊領域也大有可為。

傳統照明商轉型的希望所在

目前，昕諾飛公司仍然在加大LiFi技術的研發力度，很快還將開展新的試點項目。

對于昕諾飛來說，LiFi技術代表著一次雖然艱難，但又十分必要的轉型。傳統照明行業的商業模式已經有100多年的歷史了，以前的燈泡基本上使用18個月左右就要更換，但LED燈泡的設計壽命卻長達幾十年。隨著LED照明技術成為主流，傳統照明行業要想繼續生存和發展，就不得不進行艱難的轉型。

因此，傳統照明企業正在竭盡全力轉型成IT公司。它們把光線和照明設備變成IT網絡的節點和骨架。LiFi技術就代表了照明企業的這種嘗試。今年早些時候，昕諾飛的首席執行官洪岸禮曾經對分析師表示，LiFi是昕諾飛公司三大“最新最有前景的增長平臺”之一。

昕諾飛要成功轉型，就要打造能拿得出手的“拳頭產品”。向數字技術轉型會給企業帶來沉重的經濟負擔，迫使企業必須經歷一段長期的重組和裁員過程。2018年，昕諾飛公司兩次下調了預期，最終，其年度凈收益為2.61億歐元，下降了7.2%；銷售額也下滑至63.6億歐元。今年10月25日，昕諾飛公布其2019年第三季度財報。

昕諾飛并不是唯一一個正在經歷這種痛苦轉型的公司。全球第二大照明公司歐司朗（總部位于德國慕尼黑）也陷入了同樣的困境，目前正在謀求出售。今年早些時候，通用電氣也將旗下一家處境艱難的智能照明集團賣給了紐約的私募公司American Industrial Partners。

對于昕諾飛來說，LiFi則至少讓它有了破繭重生的希望。（財富中文網）

譯者：樸成奎

The world’s largest lighting company thinks it has just the thing for people fed up with wobbly WiFi signals that cut out, slow down or don’t work at all in cafes, parks, airports and other public places where the technology can be deeply unreliable.

Signify—the former Philips Lighting—has for years been developing an alternative broadband technology that transmits the Internet using light waves from commercial LED light fittings rather than the radio waves of WiFi. Now, in a recently announced deal it’s teaming up with one of the world’s largest telecommunication firms, Vodafone, in a bid to turn the technology into a daily reality.

But for Signify and its cohorts in the lighting industry, marketing new transmission technology isn’t just an effort to expand into new markets. Since LED bulbs went mainstream and destroyed the lighting firms’ century-old business model of selling replacement bulbs, it’s about remaining relevant—or even just surviving.

Guaranteed bandwidth

The technology is called LiFi (“Li” stands for light, as opposed to “Wi” for wireless), and it works by adding a signal modulator that rapidly starts and stops light signals in a manner imperceptible to the human eye, but which creates all the zeros and ones to which tablets, laptops, smartphones, modems, routers and the like are accustomed—a bit like fiber optics without the fiber.

“I will never say that LiFi will replace WiFi,” said Michel Germe, global head of LiFi systems at Eindhoven, Holland-based Signify. “But with LiFi you can guarantee high speed, and you can guarantee bandwidth.”

Providers of WiFi cannot honestly make such guarantees, because WiFi uses radio waves, which are subject to interference from a range of sources. For starters, they often clash with each other, causing annoying reception difficulties in public spaces where multiple WiFi networks compete for attention.

The interference, as well as other factors inherent in WiFi, can cause delays, known as latency, which effectively slow down WiFi even if it has a nominally high bandwidth. In other words, WiFi often runs slow, no matter how many megabits per second its bandwidth rating is.

WiFi can also clash with the radio signals of sensitive medical equipment, or with digitized shop floor machinery, which is why WiFi networks are sometimes banned in those environments.

At the root of those problems is the unfortunate fact that there is simply not enough room in the radio spectrum to keep WiFi networks apart. And even if the entire radio spectrum were available to WiFi, the amount of available space would still pale in comparison to the light spectrum, which is between 1,000 and 10,000 times broader.

In another advantage, LiFi is generally more secure than WiFi, because determined outsiders can easily hack into unsecured radio signals, which spread out beyond windows and walls. Access to LiFi requires a direct line of site to the light source, making hacking from outside far less likely.

The technology’s possibilities prompted Vodafone’s German operation on Oct. 1 to team with Signify to potentially make LiFi part of Vodafone Deutschland’s 5G network, which Vodafone switched on in several German cities this year.

Pitfalls

The LiFi of the press releases sounds grand. But like any new and emerging technology, things aren’t quite as rosy as they appear.

One big impediment is that gadget users cannot receive LiFi signals unless they attach a specially equipped USB stick—known as a “dongle”—to their device. While computer and phone makers long ago started embedding WiFi receivers inside end user devices, they have yet to do so with LiFi.

The chipsets exist, but the Apples and Samsungs of the world have so far stayed away. One reason: a standards battle is dragging on, with Signify backing a design endorsed by the Geneva-based International Telecommunication Union (ITU) and others going for one approved by the Piscataway, NJ-based Institute of Electrical and Electronics Engineers (IEEE). On a related note, the costs will probably be prohibitive until mass adoption kicks in.

With the dongle posing a user inconvenience, commercial installations have been few and far between. In Signify’s case, the company has publicly identified 60 pilot installations, each a one-off trial, but none with any immediate large scale, enterprise-wide impact.

The most recent of those is at the Volkspark soccer stadium in Hamburg, Germany, which last month outfitted its press room with LiFi so that journalists can send their stories via the lightwaves rather than scrambling for WiFi access (which remains switched on).

The reviews at Hamburg so far could be better.

“We have not had any major technical issues, but as it is a rather new technology… there still seems to be potential for optimization, particularly in terms of user friendliness,” said Daniel Nolte, segment leader of area organization and infrastructure for Hamburger SV, the team that plays at and owns Volkspark.

Most reporters have continued to opt for WiFi, although the few reporters who have chosen to use the LiFi “seem to be happy” with it, Nolte said, noting that the club leaves dongles out in the designated LiFi area. One problem has been that journalists who use Apple devices have to load extra software to drive them (Windows users do not).

How LiFi fits in a 5G future

One major issue that neither Vodafone nor Signify has addressed is exactly how LiFi will fit into a 5G future—and whether that future might make LiFi irrelevant.

In recent months, network operators have begun rolling out 5G, the telecom world’s newest and fastest mobile network.

It is known to have difficulty penetrating walls and windows, which offers an opening for LiFi. But a big concern for Signify is that significant efforts are already underway to boost 5G indoors. Network operators—including AT&T, T-Mobile, KT, and Signify partner Vodafone—are eager to crack the challenge, and AT&T has said it will offer indoor 5G service at AT&T Stadium in Arlington, Texas.

Hardware technology companies such as Ericsson and Qualcomm, to name just two, are also working on the issue via various schemes, including one known as “distributed antenna systems.” And just late October, Intel and Corning teamed up to boost 5G indoors using software and other means.

“It’s early days,” said Germe, who believes that LiFi can be the means to carry 5G’s blistering speed indoors. Germe also notes that LiFi could be used to help driverless vehicles communicate with each other to assist in braking and steering instructions, and play other roles in machine-to-machine communications.

Staying relevant

Today, Signify is pushing on, and is expected to soon announce projects beyond its 60 pilots projects.

For Signify, LiFi is part of an ongoing and difficult transformation that the traditional lighting industry has been facing ever since LED bulbs went mainstream and, with their long life—they are designed to last for decades—undermined the century-old business model of selling replacement bulbs every 18 months or so.

Lighting companies are desperately trying to recast themselves as IT companies, using lights and the lighting infrastructure as the nodes and backbones of IT networks. LiFi is part of that effort for Signify; earlier this year, CEO Eric Rondolat told analysts that the technology is one of three key “new and promising growth platforms” at the company.

Signify will need something. The transformation towards digital technology has been a big financial burden that has forced it into a long and ongoing restructuring and headcount reduction. In 2018, the company twice revised its outlook downward before reporting that net income for the year declined 7.2% to €261 million as sales slipped to €6.36 billion. It is scheduled to report its 2019 third quarter on Oct. 25.

Signify is hardly alone in its painful transformation. The world’s second largest lighting company, Munich-based Osram, has suffered similar travails and is now up for sale. For its part, GE sold its struggling smart lighting group to New York private equity firm American Industrial Partners in a transaction that closed earlier this year.

At Signify, at least, the hope is that LiFi will help brighten up the balance sheet.