比WiFi更可靠？全球最大照明公司押宝LiFi

在咖啡厅、公园、机场等公共场所，WiFi是个很不靠谱的东西，时断时续的信号经常令人抓狂。不过全球最大的照明公司却认为，它已经掌握了能够替代WiFi的技术。

这家公司名叫Signify，中文名字叫“昕诺飞”，也就是以前的飞利浦照明。昕诺飞这几年致力于研发一种新型宽带技术，它能够利用商用LED灯具的光波来传输网络信息，而不是像WiFi那样使用无线电波。根据最近公布的一项协议，昕诺飞将与全球最大电信运营商之一的沃达丰（Vodafone）展开合作，以使这项技术早日变成现实。

对昕诺飞以及照明行业的其他企业来说，研发可见光无线通信技术不仅仅是为了开拓新市场。自从LED灯泡成为主流产品以来，各大照明厂商成功延续了一百多年的商业模式受到了极大冲击，因此，可见光通信技术不仅关乎照明企业的发展问题，甚至关乎它们的生存。

带宽有保证

可见光无线通信技术又叫“LiFi”，其工作原理是在照明设备上添加一个信号解调器，用来控制照明设备发出高速闪烁信号，这些闪烁信号虽然用人眼查觉不到，但是平板电脑、笔记本电脑、智能手机、调制解调器、路由器等设备却能够顺利接收到——总之，它有些像光纤技术，只不过它只有“光”，而没有“纤”。

昕诺飞的LiFi系统部门全球负责人米歇尔·格尔梅指出：“我永远不会说LiFi将取代WiFi。但是在LiFi技术下，高网速和高带宽是可以保证的。”

而WiFi技术的提供商则很少有底气给出这种保证，因为WiFi使用的是无线电波，而无线电波会受到各种信号源的干扰。首先，WiFi信号之间会互相冲突，在人员稠密的公共场所，许多个WiFi信号源难免会彼此干扰，由此导致的信号接收困难经常令人抓狂。

虽然WiFi技术的理论带宽很高，但由于信号干扰问题，以及WiFi技术与生俱来的一些制约因素，经常会导致网络传输中的延迟，进而导致网速下降。换句话说，不管WiFi的带宽率是多少兆每秒，实际上它的网速经常是很低的。

有的时候，WiFi还会与一些敏感的医疗设备或生产设备的信号发生冲突，这就是为什么有的医院或生产车间里要禁用WiFi。

造成这些问题的根源，是由于无线电的频谱没有充足的空间让各个WiFi网络彼此隔离。即便全部无线电频谱都可以用于WiFi技术，它的可用空间与光谱相比仍然相形见绌。因为光谱比无线电频谱至少大出1000到10000倍。

LiFi的另一个优势，是它一般来说比WiFi更安全。无线电信号可以穿透窗户和墙壁，一旦WiFi网络的安全性做得不好，就很容易被外部不法分子侵入。而要想连入LiFi网络，就必须处在光源能够直接照射的范围内，这就大大降低了网络从外部被入侵的可能性。

正因为LiFi技术的巨大的潜能，沃达丰的德国分公司从今年10月1日起与昕诺飞展开了合作。今年，沃达丰已经在德国的几个城市开通了5G网络。下一步，沃达丰很可能会将LiFi技术用于其5G网络的布建。

LiFi的缺点

从媒体报道上看，LiFi的前景似乎很美好。不过就像其他所有新兴技术一样，任何事物都是有缺点的。

首先，目前我们使用的手机等智能设备是不能直接接收LiFi信号的，除非插入一个特制的USB“接收器”。各大电脑和手机厂商从很早以前就开始在设备里安装WiFi接收器了，但还没有哪家厂商在智能设备里内置LiFi接收器。

目前，LiFi接收器的芯片技术是不存在障碍的。苹果和安卓阵营之所以都没有安装LiFi接收器，一定程度上是由于标准之争尚未尘埃落定。目前，昕诺飞支持的技术方案有国际电信联盟（ITU）的背书，而其他照明厂商支持的另一方案则有美国电气电子工程师学会（IEEE）的支持。另外，在LiFi接收器被大规模采用之前，它的成本必然很高，会让很多手机厂商望而却步。

使用USB接收器当然会给用户带来不便。另一个问题则是目前已经安装的商用LiFi网络太少。昕诺飞目前只试点安装了60多个LiFi信号源，每个都是一次性和试验性的，而且都没有立即产生大规模的、企业级的影响。

最近的一次是在德国汉堡的人民公园足球场。上个月，该球场的媒体室安装了一台LiFi设备，这样记者们就可以通过LiFi网络发稿了。（不过同时，该媒体室也有一个WiFi网络作为“备胎”。）

从用户的评论看，这项技术应该还有改进的空间。

汉堡体育俱乐部的区域组织和基础设施负责人丹尼尔·诺尔特表示：“我们没有遇到任何重大的技术问题，但它是一项很新的技术……似乎仍然有优化的潜力，特别是在用户友好度方面。”

诺尔特表示，大多数记者仍然选择使用WiFi网络，不过也有少数几人使用了LiFi网络，并且对这项技术“似乎很满意”。俱乐部在LiFi的指定连接区域放了几个信号接收器。不过问题是，使用苹果设备的记者必须加载额外的软件来驱动这些设备。（Windows用户则不需要。）

LiFi如何融入5G时代？

有一个问题很重要，但是沃达丰和昕诺飞目前都没有给出明确答案，那就是LiFi将如何融入即将到来的5G时代——以及5G是否会让LiFi沦为边缘技术。

最近几个月，各大网络运营商纷纷开始推出5G网络。5G也是目前全球最新最快的移动网络。

众所周知，5G信号对墙和窗户的穿透能力比较差，这是它的弱点之一，这也给LiFi技术留下了一个机会。不过各大运营商都在想方设法解决室内5G服务的问题——比如AT&T、T-Mobile、韩国电信，以及昕诺飞的合作伙伴沃达丰等等。AT&T还表示，很快它就将在德州阿灵顿市的AT&T体育馆提供室内5G服务。

与此同时，爱立信和高通等硬件公司也力求通过各种方案来解决这个问题，其中呼声较高的是一种名叫“分布式天线系统”的方案。就在10月下旬，英特尔还与康宁公司展开合作，尝试通过软件等手段，推动5G网络的室内应用。

“这项技术还处于早期阶段。”格尔梅认为，LiFi可以在室内实现极高的5G网速。另外，LiFi技术还可以用于无人驾驶领域，帮助无人驾驶汽车实现相互通讯，使汽车更好地做出制动或者转向等指令。另外，LiFi在机器对机器通讯领域也大有可为。

传统照明商转型的希望所在

目前，昕诺飞公司仍然在加大LiFi技术的研发力度，很快还将开展新的试点项目。

对于昕诺飞来说，LiFi技术代表着一次虽然艰难，但又十分必要的转型。传统照明行业的商业模式已经有100多年的历史了，以前的灯泡基本上使用18个月左右就要更换，但LED灯泡的设计寿命却长达几十年。随着LED照明技术成为主流，传统照明行业要想继续生存和发展，就不得不进行艰难的转型。

因此，传统照明企业正在竭尽全力转型成IT公司。它们把光线和照明设备变成IT网络的节点和骨架。LiFi技术就代表了照明企业的这种尝试。今年早些时候，昕诺飞的首席执行官洪岸礼曾经对分析师表示，LiFi是昕诺飞公司三大“最新最有前景的增长平台”之一。

昕诺飞要成功转型，就要打造能拿得出手的“拳头产品”。向数字技术转型会给企业带来沉重的经济负担，迫使企业必须经历一段长期的重组和裁员过程。2018年，昕诺飞公司两次下调了预期，最终，其年度净收益为2.61亿欧元，下降了7.2%；销售额也下滑至63.6亿欧元。今年10月25日，昕诺飞公布其2019年第三季度财报。

昕诺飞并不是唯一一个正在经历这种痛苦转型的公司。全球第二大照明公司欧司朗（总部位于德国慕尼黑）也陷入了同样的困境，目前正在谋求出售。今年早些时候，通用电气也将旗下一家处境艰难的智能照明集团卖给了纽约的私募公司American Industrial Partners。

对于昕诺飞来说，LiFi则至少让它有了破茧重生的希望。（财富中文网）

译者：朴成奎

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.