NCTC's Tech Edge: Femto/Pico Small Cells Cautiously Test The Rural Broadband Waters

Deployment of public-access femtocells and picocells in rural areas – a technology touted as potentially the best way to bring 3G/4G wireless broadband to “underserved” parts of the country – looks set to remain primarily in the trial stage for 2012.

Despite hopeful predictions in some quarters of the industry, as of the start of 2012, there have been only two declared rural deployments that have gone commercial…worldwide. One of those is in Wisconsin, where cableco Mosaic became the unlikely leader of the pack with a small deployment last year. The other is in Japan, where giant SoftBank is, to at least some surprise, using satellite-based backhaul to serve remote areas of Japan.

Two other deployments, neither in the United States, also have turned heads. The first, possibly even more unlikely, is a planned rural femtocell network in Afghanistan; those plans were unveiled a year ago. What’s being called WiMAX actually will be backhaul. The second, only as a trial, is one by Vodafone, which said in November 2011 it is in the process of choosing a dozen small towns for a testbed of rural femtocell deployment. That 12-town rural trial follows a small test of open femtocells placed in a local pub, a village hall and on the roof of a telephone box in a small village.

While other test installations are widely assumed to be in progress in the United States by several Tier 2 and Tier 3 cable companies and phone carriers, neither carriers nor femtocell/picocell suppliers are willing to disclose them yet, for what were described as “competitive reasons.”

This is not to say the femtocell/picocell market isn’t healthy, albeit nowhere near as big as some had hoped by now. Growth is robust. Year over year (3Q10 to 3Q11) global femtocell revenue was up 37 percent, according to industry analysis firm Infonetics. But the vast majority of what some now called “microcells” – encompassing anything smaller than a standard macrocell – are not public access; rather, they are dedicated to in-home or corporate-campus use with restricted access. In those cases, the backhaul typically is broadband, provided by a local cable, wireline or wireless provider.

Who’s Using What?

An estimated 37 carriers worldwide currently sell access to microcells of one flavor or another, according to research house ABI, a count seconded by Alcatel-Lucent, which came up with a total of 36 (Alcatel-Lucent only counted one rural femtocell deployment, Softbank, in its estimates released in November 2011). The world’s biggest femtocell deployment is by AT&T Wireless, followed by Sprint. Together, the Number 2 and Number 3 U.S. wireless carriers are estimated to account for 55 percent of all femtocell shipments — not a single one of which is being used for rural public access…yet. AT&T is supplied by the team of Cisco and ip.access. Sprint uses Airvana-Ericsson gear.

Using a different metric, ABI estimates Ubiquisys has nailed down 28 contracts with various operators, selling via Nokia Siemens Networks (NSN) and NEC, which uses Ubiquisys femtos but its own hardware for other products such as picocells. Huawei and Alcatel-Lucent, meanwhile, are a shade behind, with 27 contracts each (as the numbers reflect, some operators have contracts with more than one supplier). But with the market still in its infancy, not everyone buys those numbers. Ubiquisys, for instance, in October claimed to have more than 50 carrier engagements worldwide.

In all, 2.5 million femtocells are believed to have shipped last year, somewhat less than the 3 million to 4 million once predicted, ABI says.

That shortfall is no surprise to Andy Tiller, senior vice president/Product Strategy and Marketing at ip.access, who voices a high-tech truism many forget: “New technology takes more time than everybody hopes.” As for rural deployment, he continues, there are issues that go beyond those of using femtocells to boost cellular performance inside a building. Those issues are environment and backhaul.

Tiller continues, “In the rural environment, you’re going to have to provide backhaul that has enough bandwidth for people to browse on an iPhone, especially as you go to the higher data speeds. It’s by no means certain you’re going to have the backhaul, even in built-up areas.”

He adds, “When you go outdoors, you’ve got a whole different set of technical challenges” from when femtocells are used inside a building. The first is simply environmental: packaging the femtocell to withstand rain, snow and whatever else nature throws at it. That’s sure to be an issue in the rural femtocell deployment planned for Afghanistan, with ip.access as the picocell and femtocell provider.

Interference

The second issue is not a piece of good news for rural femtocell deployments: There are coordination and interference issues to be solved when femtocells are located in areas also served by macrocells.

“Sixty-one percent of the operators see potential interferences with the macrocell network as the top technical challenge when deploying small cells,” says Infonetics in a newly released report, although “only 50 percent rate it a strong barrier to adopting small cells.” But “rural in a sense is very easy (because) there’s nothing around it. You don’t have to worry about interference because there’s nothing around it,” ip.access’ Tiller posits.

On the other hand, rural areas are the least likely places to find sufficient backhaul capacity. “In order to make these rural small cells pay, you have to control the costs,” notes Ben Ansell, small-cell marketing manager at NSN. “If you have to run a fiber in there, that starts to get expensive. Remember, this is not just a narrowband voice network you’re providing.” He agrees with Tiller when it comes to rural microcell deployment.

The Bright Spot

One backhaul bright spot for rural microcell deployments is the changing nature of satellite-based broadband, Tiller adds, citing the ongoing rollout of Ka-band satellite services worldwide.
“The economics of satellite backhaul are changing a lot,” he says. “Companies are beginning to use the Ka-band. Previously, (satellite) backhaul was pretty expensive.”

NSN’s Ansell also notes femtocells probably are not the real solution for rural deployments; rather, picocells, with their higher capacity, are what the market needs.
“The issue is that femto is very small capacity,” he notes, citing a maximum of eight users for a typical femtocell and a range in the tens of meters. Picocells, according to NSN, have about the same range, but perhaps five times the power and capacity. The way NSN sees it, what it terms microcells (with a range of hundreds of meters and even higher power) are a more likely solution for rural deployments.

In any case, Ansell reports, the jury still is out as to which small cell is the right one for rural deployments: “There’s a kind of debate going on with some of our customers whether they use a new base station or whether they use a repeater” that essentially feeds signals back to a macrocell.

Enter Small Cells

Not so, says Ubiquisys. The U.K. firm says that, working with Taipei’s Tecom, the two have developed a range of small cells based on what it calls “Femto-Engine intelligent cell software” that eliminates the quandary of which device to use.

“By automating traditional radio planning, Ubiquisys technology has changed the economics of coverage and capacity forever — not just for residential, but for enterprise and public spaces as well,” says Ubiquisys CEO Chris Gilbert. The company describes the offerings as “a unique range of public space and rural small cells.” It doesn’t yet make public claim to any rural deployments for the new widgetry, unveiled in October 2011. 

And working with Intel, Ubiquisys is set to unveil what it calls “EdgeCloud” technology, which it describes as “a new class of intelligent small cells that combine the best of the cellular and cloud computing worlds.” That’s supposed to be able to bring cloud-computing capabilities to the microcell world, in rural and other deployments. (Editor’s note: Ubiquisys is funded in part by Google.)

Finally, coming down the pike are small cells that support 4G Long Term Evolution (LTE). The Ubiquisys/Tecom team says it will have such devices this year, as does just about every other company in the business.

“With the 3G small-cell market growing strongly, operators are now committing in ever-greater numbers to LTE small cells which will be deployed increasingly in 2012,” comments Dimitris Mavrakis, principal analyst at Informa Telecoms & Media. Indeed, some are predicting micro- and picocells will dominate the LTE generation of public access, eclipsing the currently dominant macrocells. The uptake of those LTE cells in the rural market is likely to be significant because rural iPhone, Android and Windows Phone users are just as bandwidth-hungry as their urban counterparts, although just how significantly won’t be clear for at least another year.

Stuart Zipper is a freelance technology reporter and a frequent contributor to Communications Technology publications. Contact him at [email protected]