Operators ‘ready to try’ Bell Labs’ cubes in small-cell LTE, says Alcatel-Lucent's Marcus Weldon
20 March 2012
Small cells are essential for mobile broadband networks to make the best use of available spectrum, says Alcatel-Lucent corporate CTO Marcus Weldon — and that’s why seven operators are trying the company’s lightRadio cubes
Read more: Alcatel-Lucent Bell Labs lightRadio LTE China Mobile Verizon small cells
By Alan Burkitt-Gray
globaltelecomsbusiness.com
Seven operators are trying out Alcatel-Lucent’s small-cell lightRadio technology and the units are about to go into production to deliver 3G and LTE services.
Small cell technology, says the company’s corporate CTO Marcus Weldon, is about to create renovation — “no, a revolution more than a renovation” — in the industry. Small cells, each with a range of just 100 metres or so, are the answer to the mobile broadband industry’s spectrum crisis, he adds.
It’s an understanding that has spread across the industry in the past year or so, as operators are faced with rapid take-up of mobile data that makes service virtually inaccessible at times in certain areas: the centre of Manhattan, for example, or in sports stadiums when 80,000 people all want to check results of other matches at the same time.
Alcatel-Lucent launched its lightRadio idea at Mobile World Congress in 2011, when visitors looked askance at the company’s tiny cube, a few centimetres across on each side. “Last year people thought it was a nice concept but there was scepticism. But this year at Mobile World Congress we demonstrated it working with Telefónica,” says Weldon. “The reaction you get when people see the potential in this small box is just completely different.”
Telefónica is one of the seven companies that are working with the vendor on its small-cell system. Others include China Mobile and Verizon Wireless, plus Etisalat and Brazilian operator Oi. And two more “that won’t let us mention their names”, he says.
Small cells “provide capacity, not coverage”, he adds. “When you get small cells you solve a capacity problem. That’s when the magic is possible.”
Conventional cells cover an area a kilometre or more across in city centres — much more in rural areas. Advocates of small cells talk of operating ranges of maybe only 50 metres outdoors, and even less inside buildings.
Running out of spectrum
Why are they needed? Because we’re running out of spectrum, says Weldon, who is also a member of Alcatel-Lucent’s Bell Laboratories. He trained as a chemist — with computer science — but joined Bell Labs in 1995, just before it was spun off from AT&T, which had created the R&D powerhouse, into Lucent Technologies. For most of his career at Bell Labs, he’s championed fixed broadband, over copper or fibre. Today, he’s singing the praises of new radio technology.
But radio has its limits. LTE gives about a 30% capacity increase over 3G in the amount of data it can handle, he estimated. Enhance LTE by reducing interference and other clever techniques and you get another 30% increase.
Eventually “you might get a factor of two or three”, but demand is rising so fast “that we’re talking about a factor of 30”, he says. Spectrum left vacant by the end of analogue TV “gives you a year” of growth in demand. “The only way to buy the future is with small cells — spatial reuse.”
In a way, that’s just what cellular systems did when Martin Cooper invented the technology at Motorola in the 1970s: frequencies can be used over and over again by different base stations. But base stations then covered whole city centres. (By the way, Cooper’s first cellular call, in April 1973, was to the then research director of Bell Labs, Joel Engel.)
Almost four decades later, the industry has widely accepted it needs to use small cells so that spectrum can be used every few metres instead of every few kilometres. And lightRadio is Alcatel-Lucent’s offering to the small cell market.
The company needs it. Worldwide it is fourth in the cellular infrastructure market, behind Ericsson, Huawei and Nokia Siemens Networks, and many question why the company stays in the business rather than sell up to one of the others. Ben Verwaayen, the CEO of the company, is believed to be resolute that the company should stay in the business.
That seems to make lightRadio’s cubes vital to Alcatel-Lucent’s future in the business. They are more that picocells and femtocells, technology that has been promoted for years but have never really taken off.
Real traffic
“This year we are running real traffic on them, with cubes underlying a macro-cell overlay,” he says. “The macros and the cubes are talking to each other to select frequencies. Immediately people are starting to see that they are deployable,” he says.
Telefónica set up its installation in a couple of months — but that was so that 67,000 people from around the world could come and kick the tyres at Mobile World Congress in Barcelona. Etisalat “set its installation up in two hours”, says Weldon. “We sent them the instructions.”
While it is difficult to test this assertion in an interview, Weldon gives more details of the way the cubes are being developed. They’re small, so will be no more obtrusive than a wifi terminal, and the idea is that they will be installed wherever there is an electricity supply and some backhaul.
Each unit consumes only 25 watts, “a dim lightbulb”, he says, so it could be powered from a solar panel — though one larger than the cube — with battery back-up for night-time. Even Bell Labs can’t make the sun shine all day. And the company is designing a backhaul version, with the time-division duplex version of LTE or wifi daisy-chained to the nearest unit with fibre access.
So cubes could be put on top of a bus shelter, he says. Ultimately models will cover a frequency range of 700 megahertz to 2.6 gigahertz, he says, so an operator will need only one to serve the whole spectrum — or, indeed, the cubes may be shared between operators. “You don’t want to see a row of 10 on the bus shelter.”
Bell Labs has put a lot of science and technology into the antenna, which Weldon says “looks like a swiss roll, that can shape beams”. That means it will be possible to point the beams at hotspots — station entrances, for example — or through windows into office buildings. “It means you won’t have to go into the buildings with the cubes and the fibres.”
The message is that cubes could be installed quickly and simply — compared with the months or years to plan and install a macro base station — in hardly more time than it takes to put in a wifi hub. And while we’re on the subject, wifi capability is added free, he adds.
The company is making cubes with either 3G or LTE capability, but not both. “No one is yet interested in both,” he says. The real potential though is for LTE, he believes, because the cubes will allow operators to install city-centre networks quickly and easily without resorting to a new set of macro base stations. “Macro cells solve the coverage problem and try to solve the capacity problem — but that shouldn’t be solved from a kilometre away.”
Two of the companies doing most to promote LTE are Verizon Wireless — with around 60% of the world’s customers so far — and China Mobile. The similarities? “Regulatory certainty and ambition,” says Weldon.
One of the significant changes of the past few years is the way US operators have taken the lead in mobile after many years of lagging behind Europe and Asia. There is innovation from Silicon Valley — in the shape of Apple, Google and others — that follows years of “poor DSL and low-bandwidth wireless”, says Weldon. “The device manufacturers have woken up to the US market”, and Apple’s new iPad has LTE for US and Canadian spectrum allocations, “and there’s a rumour that a European version will follow”.
This is driving operators to want to install LTE quickly, especially in city centres where tablet owners will want to sit in their favourite coffee shops and check their emails and read the news. “In Europe I see in three years there will be much more LTE, built in small metro-cells, with macro-cells installed over a longer period”.
Unlicensed spectrum
Small cells and the tablet, along with smart phones, may transform opportunities for unlicensed spectrum such as wifi, thinks Weldon, failing to link his iPad to Global Telecoms Business’s office wifi in a basement meeting room. There’s a potential to provide just LTE and wifi in a small cell, he suggests, with wifi authentication and encryption controlled via the SIM card, and even with smooth handovers from LTE to wifi and back again, without the user knowing. “As a user, I don’t care. I want to best connectivity at the best value.”
LTE’s low latency, of less than 100 milliseconds, means users feel the response is almost instantaneous, and that also opens the doors to cloud services, he says — unfortunately unable, because the wifi doesn’t connect, to show how he can edit a document with a cloud version of Microsoft Office in CloudOn, a free app for iPad users.
“The iPad isn’t powerful enough for the full Office,” he says. Tablets will always be about four years behind current computers in terms of memory and speed. The answer is to put business software in the cloud and link via LTE, he adds. “The network becomes critically important but not just as a bitpipe.”
Operators will take charge of the quality of service for different applications — office software, where limited bandwidth is needed but latency is critical, as well as games, video and communications. “Operators will sign partnerships with apps companies so they will leverage a common set of APIs [application programming interfaces] and deliver the service to the user,” he says. “The network will be guaranteed to be optimised for the service.”
LTE and cloud services will drive the need for small cells, he adds. So when are we going to see Alcatel-Lucent’s lightRadio cubes in active service in operators? Weldon is coy about giving details about the company’s sales process, but hints that companies will try them in special occasions and then — he hopes — decide to follow up with the full order.
It would be ideal for something like the Olympics, he smiles — but this year’s games, in London in July and August, is too soon. The next summer Olympics, in Rio in 2016 — or the football World Cup, right across Brazil in 2014 — would be well timed, though. He didn’t say it, but put that information alongside the list of interested operators. GTB
Further reading from Global Telecoms Business:
Senator and Bell Labs accept GTB awards 07 Jun 2011
China Mobile joins Alcatel-Lucent lightRadio 20 Apr 2011
NSN unveils new mobile architecture 22 Mar 2011
Interview: Jeong Kim of Alcatel-Lucent Bell Labs 15 Jan 2010
Bell Labs aims for 1,000-fold cut in energy 11 Jan 2010
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