GigaOM » hetnet

Ericsson, Nokia Siemens lay the groundwork for HetNet with new Wi-Fi technology

Kevin Fitchard — Thu, 23 May 2013 00:29:28 +0000

Wireless equipment makers Ericsson and Nokia Siemens Networks took important first steps toward the future heterogeneous networks this week at CTIA Wireless. Both vendors announced new traffic steering technologies that make Wi-Fi and cellular data networks play nice with one another.

Today Wi-Fi and 3G/4G networks sit side by side, but they hardly work together. When you’re in the presence of an authorized hotspot your device will log in, leaving the cellular connection behind. As you wander away from the access point, your Wi-Fi connection gets weaker to the point of uselessness until your device finally disconnects and forces its way back onto the cellular grid. It’s hardly an ideal or seamless experience.

These new traffic steering technologies, however, make what were once two distinct networks act as one, selecting the optimal connection at any given moment. So if you suddenly wander into a congested hotspot, the network knows to keep you connected to your 3G cell, instead of forcing you onto a useless Wi-Fi link. As the congestion levels change on those two networks, the user’s device is shifted between them in real time.

This kind of traffic steering will be a key component of heterogeneous networks, or HetNets, which will make use of different radio technologies to create multi-layered and tremendously high-capacity mobile networks. But according to Petri Hautakangas, Nokia Siemens North American head of technology, it’s just a first step. Networks and devices will eventually be able to balance traffic between networks, as well as ship data simultaneously across multiple radio connections, he said.

For Ericsson, the news also represents the full integration of BelAir Networks’ Wi-Fi hotspot technology into its cellular architecture after acquiring the Canadian vendor last year. Nokia Siemens doesn’t make its own Wi-Fi gear but it partners with Wi-Fi access point and hotspot makers like Ruckus Wireless.

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Ericsson trials HetNet-friendly ‘City Site’: Would you like ads with your base station?

David Meyer — Fri, 03 May 2013 09:20:45 +0000

As cities get more populated and data usage increases, cracks start to show in traditional mobile network layouts – they just can’t handle the load. Many see the solution in so-called heterogeneous networks, or HetNets, which involve a range of different cell types rather than simply relying on the macro-cells we know and love (or loathe, depending whose skyline they’re ruining).

Ericsson is a keen HetNet proponent and the Swedish networking giant has just launched a commercial trial of what it calls the City Site “integrated solution” in Nanning, the capital of China’s Guangxi region, alongside China Mobile. The four-meter-high (13-foot) package includes a standard Ericsson base station in this case, along with an integrated multidirectional antenna.

The “Omni Antenna” in question is rather short-range (up to a couple of hundred meters) and relatively close to the ground, which fits in nicely with what Ericsson is trying to achieve here: network densification, a central tenet of HetNet architecture.

HetNets will need to involve not only a variety of cell sizes and types – from macro-cells to pico-cells to Wi-Fi offload points — but also cells at different levels and layers, in order to solve the challenges presented by specific locations. Tall buildings are a challenge when you’re trying to serve thousands of people on street-level, and this kind of thing may be part of the solution.

But densification isn’t the only thing that’s going on here. Ericsson’s City Site design also allows add-on modules for video ad screens, clocks, touchscreen real-time information displays and so on. The company told me this could “provide high performance broadband coverage together with fulfilling a city’s needs for de-clutter, aesthetics and add-on applications like information or advertising.”

This is a good indicator of how we can expect to see our ever-increasing mobile broadband requirements change the cityscapes around us. I’m not sure it really amounts to de-cluttering, though — ads aside, there’s something to be said for discreetly sticking cells on lampposts and other existing street furniture.

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AT&T’s LTE investments will go big by using small cells

Stacey Higginbotham — Wed, 07 Nov 2012 16:23:07 +0000

AT&T said on Wednesday it will spend $14 billion in boosting its wireless and wireline networks with $8 billion in expanding its LTE network. The carrier expects to cover 300 million people by the end of 2014 using new small cell technology and distributed antennas. The expansion will help support not only the mobile business, but also AT&T’s decision to abandon its old-school telephone network and rely on LTE instead.

Thus, the announcement that AT&T will use small cells to build out density is important, because it will allow more subscribers to take advantage of the limited airwaves, and is yet another carrier commitment to the HetNet concept. This idea combines the use of multiple radio technologies –from LTE to Wi-Fi — as well as a variety of different base stations and antennas to maximize the capacity of the airwaves, and is the next generation of cellular infrastructure.

In addition to its cell towers, AT&T said it will use more than 1,000 distributed antenna systems. DAS setups take the capacity of a single cell and distribute it among numerous antennas, allowing a carrier to shape cellular coverage within or around buildings rather than just blast bandwidth out from up on high.

AT&T will also use more than 40,000 small cells to build out a highly dense network that can reuse spectrum and hopefully move traffic off the airwaves and on to AT&T’s fiber networks. The initial deployments of these dense networks will begin in the first quarter of next year and will work with the 3G UMTS and HSPA+ networks that AT&T has deployed. By 2014 AT&T will support LTE on these small cells as well. Both Verizon and Sprint are already exploring similar plans to make their networks more dense using small cells as well.

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How the mobile industry can support 1,000x growth in broadband traffic

Prakash Sangam, Qualcomm — Sun, 07 Oct 2012 17:30:11 +0000

Mobile data traffic has almost doubled annually over the last few years and continues to grow unabated, prompting the industry to take drastic measures. While demand projections vary, the goal of “1,000x growth” captures the sentiment. Does 1,000x sound like a tough challenge? Yes. Is it possible to support such growth? Yes, especially when you examine the technological advancements in the pipeline and put your faith in the brain trust working on future enhancements. This challenge will test a few limits of technology (literally — think Shannon’s limit) along with our belief that the human mind can use innovation to overcome big challenges.

Whenever people say “1,000 times” more, it’s usually just hyperbole. But when it comes to mobile broadband traffic growth, 1,000x is more reality than embellishment. A typical mobile device owner might ask, “Why should I worry?” Answer: overloaded networks result in lower speeds, stuttering videos, unresponsive games and other issues leading to unsatisfactory mobile experiences.

What’s needed? You start by improving existing networks—continuing to evolve 3G, 4G and Wi-Fi. But a challenge of this magnitude needs more resources and, more importantly, radically new ways of acquiring, deploying, managing and optimizing these resources.

Small is the new big

Small cells (miniature base stations) are already popular among mobile operators. However, we need more of them, everywhere — indoors and outdoors, in residences and in enterprises. And we need all the familiar flavors — 3G, 4G, Wi-Fi (often all integrated in a single box) — in all the different forms, including user installed femtos, operator installed picos, metros, relays, remote radio heads, distributed antenna systems, etc.

Deploying this heterogeneous mix of cells (aka HetNets) is just part of the story. Small cells, deployed closely together, interfere with each other and with the larger macro network. To mitigate interference, advanced techniques must be employed, which substantially increases overall network capacity — more so than merely adding small cells. Some of these techniques are already developed and the industry is focused on further enhancing them and developing more to make extremely dense deployments of small cells more robust. Research shows that overall network capacity scales with the density of small cells, validating that reaching 1,000x capacity is more a question of when and how rather than if.

With so many variables involved in deploying small cells, there are numerous combinations of business cases, deployment models and market introduction strategies to choose from.

One promising example is the “Neighborhood Small cells” model — a network of extremely low-cost, plug-and-play, open, indoor small cells. It provides extremely high indoor capacity as well as good outdoor coverage and capacity in the immediate “neighborhood.” This model is cost effective because consumers deploy the small cells and provide the backhaul, saving operators time and money. Studies show capacity increases of up to 500x with a mere 9 percent penetration of households and up to 1,000x with 20 percent penetration, when combined with 10x more spectrum.

Spectrum, precious spectrum

Spectrum is one resource that operators always want more of. Unfortunately, there’s just not enough to go around. One opportunity for new 3G/4G spectrum is in higher bands such as 3.5 GHz. Because of their smaller coverage, these bands were previously underutilized, but that limitation actually makes them attractive for small cells, since smaller coverage reduces interference.

In cases where clearing spectrum is not possible, the industry is proposing a new regime called Authorized Shared Access (ASA), which can potentially unlock hundreds of MHz of spectrum for 3G/4G services.

Because of the nature of their operations, many spectrum holders, such as government users, do not use the entire block of allocated spectrum in all of their licensed regions on a 24×7 basis. For example, U.S. naval radar uses spectrum only on the coastline, although the Navy is allocated that spectrum countrywide. In such cases, ASA allows incumbent spectrum holders and 3G/4G operators to share this underutilized spectrum (based on location or time) on mutually beneficial terms, without interfering with each other.

Of course, we also need more unlicensed spectrum for Wi-Fi, especially, for the next generation which leverages wider bandwidths to offer extremely high data rates. Recently, operators have overwhelmingly embraced Wi-Fi, because it allows them to opportunistically offload traffic from strained 3G/4G networks.

More than the sum of its parts

With networks and mobile devices becoming so complex, and with the apps and services market showing explosive growth, it’s essential that the individual parts of the network are optimized and work in harmony to offer higher overall capacity and better user experiences.

A good example is the scenario where a device is within the coverage range of 3G, 4G, Wi-Fi and others, served by both macro network and small cells. Devices should have the intelligence to select the most appropriate link(s) among all these, based on the signal level, possible data speed, network congestion, and the actual application or service it is using, etc., so that the user gets the best experience, while maximizing overall system performance.

There are also many innovative technologies that exist today, or are in development, that can increase the capacity for specific applications. For example, LTE Broadcast (eMBMS) allows operators to efficiently offer multimedia services in a broadcast mode when a high concentration of users accesses the same content simultaneously. LTE Direct is another technology that allows devices to efficiently and directly connect to each other (for peer-to-peer applications) without having to route the connection through the macro network.

A tailor-made strategy

Given the diverse nature of the mobile business, obviously there is no one-size-fits-all solution. Each operator must tailor a strategy that suits its needs. However, the bottom line is, no matter how extraordinary the 1,000x challenge appears, it is indeed possible to find solutions that will successfully meet the growing demand for mobile data.

Prakash Sangam is a senior manager of technical marketing at Qualcomm. He can be reached on Twitter @qualcomm_tech.

Image courtesy of Flickr user daryl_mitchell.

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Sprint will use the biggest vendors to build its smallest cells

Kevin Fitchard — Fri, 10 Aug 2012 21:57:15 +0000

If the growing number of small cell specialists is hoping to break out big in the United States, they should probably look at other carriers than Sprint. The country’s third-largest mobile operator revealed two vendors for its small cell rollout, and they happen to be the same companies that are building its primary umbrella network.

Sprint will be one of the first carriers to use Alcatel-Lucent lightRadio Cube metrocell architecture, and it will deploy Samsung’s own miniature base stations throughout its footprint. These pint-sized cells pack a lot of capacity into a tiny area compared with macrocells, which spread their bandwidth over a much larger space.

Sprint will initially focus its small cell rollout on high-traffic indoor venues, such as stadiums, transportation hubs, conference centers, hotels and airports. But eventually those small cells will begin to eke outside, supplying a dense layer of capacity in urban environments under the macro umbrella.

Sprint will almost certainly assign Samsung and Alcatel-Lucent venues in the same markets they’re building Sprint’s new CDMA and LTE networks. Sprint has a third infrastructure vendor as well, Ericsson, so don’t be surprised if we see another small cell announcement come out in the next few weeks.

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How O2 is using the Olympics to lay a foundation for small cells

Kevin Fitchard — Fri, 27 Jul 2012 19:50:10 +0000

U.K. operator O2 has launched a new free-to-use outdoor Wi-Fi hotspot network in London, just in time for the Olympics. The scope of the network isn’t big — only 100 access points compared with the 1,500 that BT is installing for the Olympics — and it’s centered in London’s high-tourism West End. But there is something special about this tiny Wi-Fi launch.

O2 is using these 100 hotspot deployments as the infrastructure groundwork for a future small-cell network. Like Wi-Fi, small cells will deliver surgical capacity in high-trafficked areas, but unlike Wi-Fi, those cells will use O2’s licensed spectrum, providing a big boost of mobile broadband capacity exactly where its macro network is most congested. According to O2 Wi-Fi managing director Gavin Franks, the carrier is targeting the end of the year for the small-cell rollout.

“What we have deployed so far isn’t a full-fledged small cell network,” Franks said. “We have deployed a future-proof network that allows us to easily get to small cells. And obviously it’s our intention to do so.”

It might seem easy to task Wi-Fi nodes for double duty as small cells, but Franks said O2 had to plan its deployment carefully for the hybrid configuration. The dual radios will require more backhaul capacity than the DSL connections that usually power Wi-Fi can provide, so O2 has either run fiber or installed microwave radio links to hotspot clusters, which are then meshed together via Wi-Fi backhaul. Franks said O2’s mobile network planners determined the placement of each node beneath the macro network to ensure there would be no interference when the small cells went live. Finally O2 ordered up specialty outdoor Wi-Fi equipment from Ruckus Wireless that can easily support the installation of micro-cellular base stations in the future.

When the time comes, Franks said, O2 technicians will simply pop the chassis of the Ruckus access point, insert the 3G radio, and instantly have a live small cell. Ruckus makes its own 3G and LTE small-cell modules, but that doesn’t necessarily mean O2 will buy them. Ruckus has also partnered with Nokia Siemens Networks to provide an integrated Wi-Fi-cellular small platform, and NSN also happens to be one of O2’s primary network suppliers.

Of course, 100 small cells isn’t exactly an ambitious network. To get to a true heterogeneous network, or hetnet, O2 would need to layer thousands if not tens of thousands throughout London, providing a dense layer of high-capacity nodes under the macro network’s coverage umbrella.

But Franks said O2 is only in the first phase of its plans. This small-scale rollout will test the efficacy of small cells as well as its free Wi-Fi model. If they prove useful, O2 will look to expand the network throughout the U.K. as well as coordinate with its parent company, Telefonica, on international launches. But as of now, Franks said, O2 doesn’t envision creating small-cell networks on a grand scale. O2 is taking a more practical approach initially, using Wi-Fi and small cells to target high-demand areas rather than planning a ubiquitous network of tiny nodes.

Still, there is a lot of potential here for O2 to go big if it wants to. Unlike other carriers deploying Wi-Fi, O2 doesn’t plan to integrate hotspots with its mobile network or sell capacity to outside customers. “We don’t see any value in charging for Wi-Fi,” Franks said. “People just aren’t willing to pay for it.” Instead it wants to make its money through value-added services, such as selling multimedia or offering digital-wallet capabilities. If that model works, it could find itself putting up Wi-Fi all over the U.K. — and small cells would come along for the ride.

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GigaOm Interview: CEO Hans Vestberg on the future of Ericsson

Tom Krazit — Wed, 06 Jun 2012 00:59:33 +0000

You don’t make the decision to wind down a 130-year-old business without a little bit of angst, said Hans Vestberg, CEO of Ericsson, reflecting on his company’s decision to end a joint partnership with Sony last year. But at a certain point, logic has to trump emotion.

“The whole handset business has transformed from being an extension of the network,” Vestberg said Tuesday in an interview with GigaOM before a media briefing in San Francisco about the future trends (covered here by Kevin Fitchard earlier) that the wireless networking equipment maker is poised to exploit. While Ericsson’s carrier customers may still be in denial about the shift in power from the network to the handset, Vestberg saw it happen firsthand while Sony Ericsson fell further and further behind, leading to a painful but necessary decision in October 2011.

“For us it was emotionally tough to drop it, but strategically it was easy.” Vestberg said. “When you start losing market share it’s really tough to gain it back, you need the product portfolio and presence in many markets.”

Now Ericsson is focused completely on its equipment business, helping carriers build out next-generation wireless networks that can accommodate the rapid shift from fixed desktop computers to mobile computers like smartphones and tablets. By 2017 the company expects that there were be 5 billion mobile broadband users, three times as many people as are using that technology today.

It expects that the concept of HetNets — vast, sprawling wireless networks made up of many different types of short-range and long-range radio technologies — will become a standard practice in the wireless networking business. We’ve covered the concepts behind HetNet quite a bit this year, but Vestberg doesn’t expect it to develop overnight.

“We don’t want people to believe that this is so simple,” he said, citing the complexities involved in making sure wireless networks of overlapping cells can operate reliably without interference and the commitment it takes to make sure there is enough backhaul to connect HetNets to the broader Internet.

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Sprint has big plans for small cells

Kevin Fitchard — Wed, 09 May 2012 23:12:57 +0000

Sprint plans to make aggressive use of small cells in its future LTE network, launching tens of thousands of tiny high-capacity base stations in high-traffic indoor and outdoor areas in 2013 and 2014. Speaking at briefing at CTIA Wireless in New Orleans, Sprint VP of network development and engineering Iyad Tarazi said the end goal of Sprint’s small-cell efforts is a heterogeneous network, or HetNet.

HetNet gathers multiple access technologies under a single umbrella to create enormous quantities of capacity no mere macro network could supply (for a detailed description of HetNet check out my recent interview with Ericsson CEO Hans Vestberg). Many operators have been talking up HetNet and the small cells that will be used to build it, but many of them tend to conflate small cells with the home and business femtocell deployments. And no one – in North America at least –has laid out such a specific or aggressive small cell strategy as Sprint did on Wednesday.

Tarazi said Sprint’s small cell rollout will occur in three phases:

This year and in 2013 it will redouble its femtocell rollouts network in homes and businesses at its customers’ requests and start using femtos to add spot coverage and capacity in indoor public areas.
In 2013, Sprint will begin a large scale rollout of picocells – think of them as small radio base stations that can be mounted on walls and poles – in high traffic indoor areas and big public venues. Tarazi said Sprint is targeting 400 buildings such as stadiums, conference centers and airports for large-scale pico rollouts, each venue supporting between 100 and 200 individual small cells.
In late 2013 and into 2014, Sprint will begin moving small cells outdoors, focusing on dense urban areas with lots of foot traffic and cellular congestion. Though Tarazi didn’t identify any specific numbers for outdoor pico deployments, he implied that they would be extensive. Picos, for instance, would be used to add capacity to large swaths of the downtown cores in major metropolitan cities like Chicago, Tarazi said.

Though there’s lots of talk of small cells flying around at CTIA most of them have to be taken with a grain of salt. Everything from home femtos to Wi-Fi access points to distributed antenna systems have been lumped together as ‘small cells,’ but Sprint is talking Small with capital “S”. By building picocells under its macro umbrella, Sprint will wind up with a multi-tiered network, with one layer devoted to coverage and other layers delivering gobs of inexpensive capacity in the areas its most needed.

Tarazi said Sprint doesn’t plan to stop there. The carrier will layer in Wi-Fi and femtos as well, and in 2013 it will begin adding Clearwire’s time-divison LTE capacity to the equation. “We plan to maximize all of those tools,” Tarazi said.

If Sprint can pull it all off – and even if some of those elements fall to the wayside – Sprint will have an high-capacity HetNet to be reckoned with.

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Can millimeter waves solve the small cell backhaul problem?

Kevin Fitchard — Wed, 11 Apr 2012 20:14:36 +0000

The mobile industry is counting on future wireless networks being heterogeneous: Rather than the honeycomb grids of big cells we have today, we’ll see complex multi-layered networks of overlapping big and small cells, supplying our smartphones, tablets and cars with enormous amounts of cheap bandwidth. But there are many problems the industry has to solve before hetnet becomes a reality – planning systems with over 100,000 nodes being at the top of the list – but one of the biggest obstacles is figuring out how to link all of those small cells back to the network.

LTE and HSPA+ require fat backhaul pipes. Operators have managed to handle those demands by laying fiber to their towers, but that option won’t be available in a hetnet world. Those small cells will be mounted on street poles, building walls and every manner of urban fixture where access to fiber isn’t ready available and the cost of laying it is prohibitive.

But there’s an emerging group of wireless radio vendors such as Siklu, BridgeWave, and, soon, E-band Communications that think millimeter wave technologies will provide both the reach and capacity at the right prices to backhaul the hetnet. E-Band this week said it raised new funding – though it didn’t reveal how much and from whom – to develop millimeter wave small mesh radios.

Millimeter waves technically encompass a huge swath of spectrum from 30 to 300 GHz, but for wireless backhaul purposes, regulators have designated three big blocks of licensed spectrum in the 70-95 GHz range for point-to-point high-bandwidth radio links. According to E-Band co-founder and CEO Sam Smookler those frequencies are ideal for small cell backhaul for two reasons:

It’s relatively easy to get licenses for big blocks of millimeter wave spectrum, which would allow carriers to deploy large backhaul pipes over 1 Gbps in size. While a single small cell may not need that much capacity, the complexity of hetnets will require daisy-chaining many small cells together, each cell passing its load down the line. The final backhaul link in such a mesh or chain winds up handling dozens of cells worth of traffic before it can dump it onto a fiber network, Smookler said.
Small cell backhaul makes the best use of millimeter waves’ high frequency characteristics. The higher the frequency the shorter distance a wave propagates unless it gets a serious power boost. But the hetnet by definition will be composed of densely packed cells in urban environments, meaning no millimeter wave will have to travel far between hops, Smookler said.

Plenty of alternatives

E-Band and other millimeter vendors aren’t the only ones trying to solve this small cell backhaul problem. Microwave is the traditional powerhouse of wireless backhaul technologies, using its longer range, lower frequency links to connect far flung towers back to the network proper. Microwave equipment vendors like Ericsson, NEC, Aviat Networks, DragonWave, and Ceregon Networks are retooling their long-haul radio designs for small cell deployments.

The lightRadio Cube, Alcatel-Lucent's vision for the small cell.

Like the millimeter folks, the microwave vendors are focusing on higher frequencies, where spectrum is plentiful enough to support ultra-fat links. The problem is those 60 GHz airwaves are all unlicensed, meaning no single operator will have proprietary use of them in any given area. That means there is the potential for interference between radios in areas where multiple carriers are running multiple hetnets of small cells.

Interference is also the knock on probably the hottest technology in small cells today: Wi-Fi. Metro Wi-Fi equipment makers Ruckus Wireless and BelAir Networks – just acquired by Ericsson – are not only building small cells that pair Wi-Fi and LTE together as access technologies, they’re also using Wi-Fi mesh architectures to backhaul those cells.

The big advantage of such an approach is its cheap: the 802.11n gear may be souped-up for carrier networks, but it’s certainly not the highly specialized equipment used in microwave systems. The problem is that everyone and their dogs, cats and hamsters are using the unlicensed airwaves of Wi-Fi. Operators will need to fight interference not just from one another, but home and business wireless networks.

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HetNet step 1: More LTE microcells than base stations by 2014

Kevin C. Tofel — Fri, 30 Mar 2012 13:56:32 +0000

By 2014, you might be using an LTE network, but the signal may not come from the towers we’re so used to seeing. ABI Research estimates that there will be more LTE microcells in place than actual LTE base stations as early as 2014. These network devices typically supplement coverage but only in small areas filled with people, such as malls, large buildings and other highly trafficked areas.

ABI calls for 127,000 LTE small cells sold, compared to 113,000 LTE macrocells, within the next two years, and there’s good reason to believe this will happen. Consumers and enterprise workers alike are fast migrating traditional computer activities to connected mobile devices. But large-scale networks are costly to maintain and expand and are limited by spectrum availability. It’s far less expensive to supplement broad coverage areas with smaller bits of infrastructure targeted at high traffic areas.

My colleague, Kevin Fitchard, suggests this forecast from ABI is a precursor to the coming emergence of the “HetNet”, or heterogeneous network. That model uses a network topology comprised of multiple access technologies: Wi-Fi, picocells, femtocells and traditional macrocell base stations. The idea is that devices can stay on the same network, even when roaming around, regardless of the specific access method. In order for that work, the number of microcells will have to far outweigh the number of base stations, so ABI’s forecast is a step in the right direction.

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