Posts Tagged ‘2.4 GHz’

Oil, gas field sensors vulnerable to attack via radio waves

Friday, July 26th, 2013

Researchers with IOActive say they can shut down a plant from up to 40 miles away by attacking industrial sensors

Sensors widely used in the energy industry to monitor industrial processes are vulnerable to attack from 40 miles away using radio transmitters, according to alarming new research.

Researchers Lucas Apa and Carlos Mario Penagos of IOActive, a computer security firm, say they’ve found a host of software vulnerabilities in the sensors, which are used to monitor metrics such as temperature and pipeline pressure, that could be fatal if abused by an attacker.

Apa and Penagos are scheduled to give a presentation next Thursday at the Black Hat security conference in Las Vegas but gave IDG News Service a preview of their research. They can’t reveal many details due to the severity of the problems.

“If you compromise a company on the Internet, you can cause a monetary loss,” Penagos said. “But in this case, [the impact] is immeasurable because you can cause loss of life.”

The U.S. and other nations have put increased focus in recent years on the safety of industrial control systems used in critical infrastructure such as nuclear power plants, energy and water utilities. The systems, often now connected to the Internet, may have not had thorough security audits, posing a risk of life-threatening attacks from afar.

Apa and Penagos studied sensors manufactured by three major wireless automation system manufacturers. The sensors typically communicate with a company’s home infrastructure using radio transmitters on the 900MHz or 2.4GHz bands, reporting critical details on operations from remote locations.

Apa and Penagos found that many of the sensors contained a host of weaknesses, ranging from weak cryptographic keys used to authenticate communication, software vulnerabilities and configuration errors.

For example, they found some families of sensors shipped with identical cryptographic keys. It means that several companies may be using devices that all share the same keys, putting them at a greater risk of attack if a key is compromised.

They tested various attacks against the sensors using a specific kind of radio antennae the sensors use to communicate with their home networks. They found it was possible to modify readings and disable sensors from up to 40 miles (64 kilometers) away. Since the attack isn’t conducted over the Internet, there’s no way to trace it, Penagos said.

In one scenario, the researchers concluded that by exploiting a memory corruption bug, all sensors could be disabled and a facility could be shut down.

Fixing the sensors, which will require firmware updates and configuration changes, won’t be easy or quick. “You need to be physically connected to the device to update them,” Penagos said.

Apa and Penagos won’t identify the vendors of the sensors since the problems are so serious. They’ve handed their findings to the U.S. Computer Emergency Readiness Team, which is notifying the affected companies.

“We care about the people working in the oil fields,” Penagos said.

Source:  computerworld.com

With faster 5G Wi-Fi coming, Wi-Fi Alliance kicks off certification program

Thursday, June 20th, 2013

Process ensures 802.11ac devices work well with older Wi-Fi products

Although faster fifth-generation Wi-Fi is already available in some new wireless routers and even the new MacBook Air laptops, a new Wi-Fi Certified ac program is being launched today to ensure the newest devices interoperate with other Wi-Fi products.

The Wi-Fi Alliance announced the certification program for 802.11ac Wi-Fi (also known as 5G Wi-Fi). Mobile devices, tablets, laptops, networking gear and other hardware will be available in the last half of 2013 with a Wi-Fi Certified label, ensuring that the devices have been tested to interoperate with other 802.11ac products and older Wi-Fi products.

“The certification program ensures that users can purchase the latest device and not worry if it will work with a device of two years or even 10 years ago,” said Kevin Robinson, senior marketing manager for the Wi-Fi Alliance in an interview.

The faster Wi-Fi allows two-to-three times faster speeds than existing 802.11n technology, Robinson said. It will enhance the speed of movie downloads and other user needs in a home or work place.

Robinson said that 802.11ac should allow a transfer of an HD movie to a tablet in under four minutes, and allow for multiple video streams inside a home at one time. “The average user will notice the difference,” he said, contrary to what some analysts have predicted.

Theoretical maximum speeds on 802.11ac can reach 1.3 Gbps, three times 802.11n’s speeds of 450 Mbps. Older 802.11g supports theoretical speeds of up to 54 Mbps. Actual speeds will be far lower, depending mainly on the number of users and the type of data being transferred.

Aside from faster speeds, 802.11ac allows for more network capacity so that more devices can be simultaneously connected to a network. Because of the added network capacity with 802.11ac, Robinson said that movies can be run without as much less compression, enhancing their overall visual quality. Wi-Fi over 802.11ac also reduces network latency, resulting in fewer delays in streaming music and gaming applications.

Wi-Fi Direct, which is technology to allow device-to-device interoperability with 802.11n, is not yet part of the 802.11ac certification program, Robinson said.

The Wi-Fi Alliance predicts that many of the new routers made with 802.11ac will operate on both the 5GHz and 2.4 GHz bands. That way, 802.11n traffic will be able to run over both bands, while 802.11ac traffic runs over 5GHz. Robinson said that 2.4 GHz will remain sufficient for carrying data for many apps and uses, such as Web browsing. Migrating to 5GHz allows wider spectrum channels with higher data throughputs, yielding higher performance. An advantage of 5 GHz is that various channel widths are supported — 20 MHz, 40 MHz and 80 MHz– while 2.4GHz allows only three 20 MHz channels.

The Wi-Fi Alliance said 11 chips and other components are being used to test new 802.11 ac devices. They are from Broadcom, Intel, Marvell, Mediatek, Qualcomm and Realtek. A list of Wi-Fi Certified ac products is available at www.wi-ficertifiedac.com.

As an indication of the fast industry adoption of 802.11ac, Aruba Networks on May 21 announced new Wi-Fi access points supporting the technology and said more recently that the University of Delaware is a beta customer. Aruba is working for Wi-Fi Certified AC certification of the new access points, a spokeswoman said.

Robinson predicted that many of the recently announced routers and other products will seek Wi-Fi 802.11ac certification.

Source:  computerworld.com

The 49ers’ plan to build the greatest stadium Wi-Fi network of all time

Tuesday, March 19th, 2013

When the San Francisco 49ers’ new stadium opens for the 2014 NFL season, it is quite likely to have the best publicly accessible Wi-Fi network a sports facility in this country has ever known.

The 49ers are defending NFC champions, so 68,500 fans will inevitably walk into the stadium for each game. And every single one of them will be able to connect to the wireless network, simultaneously, without any limits on uploads or downloads. Smartphones and tablets will run into the limits of their own hardware long before they hit the limits of the 49ers’ wireless network.

Jon Brodkin

Until now, stadium executives have said it’s pretty much impossible to build a network that lets every single fan connect at once. They’ve blamed this on limits in the amount of spectrum available to Wi-Fi, despite their big budgets and the extremely sophisticated networking equipment that largesse allows them to purchase. Even if you build the network perfectly, it would choke if every fan tried to get on at once—at least according to conventional wisdom.

But the people building the 49ers’ wireless network do not have conventional sports technology backgrounds. Senior IT Director Dan Williams and team CTO Kunal Malik hail from Facebook, where they spent five years building one of the world’s largest and most efficient networks for the website. The same sensibilities that power large Internet businesses and content providers permeate Williams’ and Malik’s plan for Santa Clara Stadium, the 49ers’ nearly half-finished new home.

“We see the stadium as a large data center,” Williams told me when I visited the team’s new digs in Santa Clara.

I had previously interviewed Williams and Malik over the phone, and they told me they planned to make Wi-Fi so ubiquitous throughout the stadium that everyone could get on at once. I had never heard of such an ambitious plan before—how could this be possible?

Today’s networks are impressive—but not unlimited

An expansive Wi-Fi network at this year’s Super Bowl in the New Orleans Superdome was installed to allow as many as 30,000 fans to get online at once. This offloaded traffic from congested cellular networks and gave fans the ability to view streaming video or do other bandwidth-intensive tasks meant to enhance the in-game experience. (Don’t scoff—as we’ve noted before, three-plus-hour NFL games contain only 11 minutes of actual game action, or a bit more if you include the time quarterbacks spend shouting directions at teammates at the line of scrimmage. There is plenty of time to fill up.)

Superdome officials felt a network allowing 30,000 simultaneous connections would be just fine, given that the previous year’s Super Bowl saw only 8,260 at its peak. They were generally right, as the network performed well, even for part of the game’s power outage.

The New England Patriots installed a full-stadium Wi-Fi network this past season as well. It was never used by more than 10,000 or so people simultaneously, or by more than 16,000 people over the course of a full game. “Can 70,000 people get on the network at once? The answer to that is no,” said John Brams, director of hospitality and venues at the Patriots’ network vendor, Enterasys. “If everyone tried to do it all at once, that’s probably not going to happen.”

But as more fans bring smart devices into stadiums, activities like viewing instant replays or live camera angles available only to ticket holders will become increasingly common. It’ll put more people on the network at once and require bigger wireless pipes. So if Williams and Malik have their way, every single 49ers ticket holder will enjoy a wireless connection faster than any wide receiver sprinting toward the end zone.

“Is it really possible to give Wi-Fi to 68,500 fans at once?” I asked. I expected some hemming and hawing about how the 49ers will do their best and that not everyone will ever try to use the network at once anyway.

“Yes. We can support all 68,500,” Williams said emphatically.

How?

“How not?” he answered.

Won’t you have to limit the capacity each fan can get?

Again, absolutely not. “Within the stadium itself, there will probably be a terabit of capacity. The 68,500 will not be able to penetrate that. Our intentions in terms of Wi-Fi are to be able to provide a similar experience that you would receive with LTE services, which today is anywhere from 20 to 40 megabits per second, per user.

“The goal is to provide you with enough bandwidth that you would saturate your device before you saturate the network,” Williams said. “That’s what we expect to do.”

Fans won’t be limited by what section they’re in, either. If the 49ers offer an app that allows fans to order food from their seats, or if they offer a live video streaming app, they’ll be available to all fans.

“The mobile experience should not be limited to, ‘Hey, because you sit in a club seat you can see a replay, but because you don’t sit in a club seat you can’t see a replay,'” Malik said. “That’s not our philosophy. Our philosophy is to provide enhancement of the game experience to every fan.” (The one exception would be mobile features designed specifically for physical features of luxury boxes or club seats that aren’t available elsewhere in the stadium.)

It’s the design that counts

Current stadium Wi-Fi designs, even with hundreds of wireless access points distributed throughout a stadium, often can support only a quarter to a half of fans at once. They also often limit bandwidth for each user to prevent network slowdowns.

The Patriots offer fans a live video and instant replay app, with enough bandwidth to access video streams, upload photos to social networks, and use the Internet in general. Enterasys confirmed to Ars that the Patriots do enforce a bandwidth cap to prevent individual users from overloading the network, but Enterasys would not say exactly how big the cap is. The network has generally been a success, but some users of the Patriots app have taken to the Android app store to complain about the stadium Wi-Fi’s performance.

According to Williams, most current stadium networks are limited by a fundamental problem: sub-optimal location of wireless access points.

“A typical layout is overhead, one [access point] in front of the section, one behind the section, and they point towards each other,” he said. “This overhead design is widely used and provides enough coverage for those using the design.”

Williams would not reveal the exact layout of the 49ers’ design, perhaps to prevent the competition from catching on. How many access points will there be? “Zero to 1,500,” he said in a good-natured attempt to be both informative and vague.

That potentially doubles or quadruples the typical amount of stadium access points—the Super Bowl had 700 and the Patriots have 375. But this number isn’t the most important thing. “The number of access points will not give you any hint on whether the Wi-Fi is going to be great or not,” Malik said. “Other factors control that.”

If the plan is to generate more signal strength, just adding more access points to the back and front of a section won’t do that.

The Santa Clara Stadium design “will be unique to football stadiums,” Williams said. “The access points will be “spread and distributed. It’s really the best way to put it. Having your antennas distributed evenly around fans.” The 49ers are testing designs in Candlestick Park and experimenting with different access points in a lab. The movement of fans and the impact of weather on Wi-Fi performance are among the factors under analysis.

“Think of a stadium where it’s an open bowl, its raining, people are yelling, standing, how do you replicate that in your testing to show that if people are jumping from their seats, how is Wi-Fi going to behave, what will happen to the mobile app?” Malik said. “There is a lot that goes on during a game that is hard to replicate in your conceptual simulation testing. That is one of the big challenges where we have to be very careful.”

“We will make great use of Candlestick over the next year as we continue to test,” Williams said. “We’re evaluating placement of APs and how that impacts RF absorption during the game with folks in their seats, with folks out of their seats.”

Wi-Fi will be available in the stands, in the suites, in the walkways, in the whole stadium. The team has not yet decided whether to make Wi-Fi available in outdoor areas such as concourses and parking lots.

The same could theoretically be done at the 53-year-old Candlestick Park, even though it was designed decades before Wi-Fi was invented. Although the stadium serves as a staging ground for some of the 49ers’ wireless network tests, public access is mainly limited to premium seating areas and the press box.

The reason Wi-Fi in Candlestick hasn’t been expanded is a practical one. With only one year left in the facility, the franchise has decided not to invest any more money in its network. But Williams said 100 percent Wi-Fi coverage with no bandwidth caps could be done in any type of stadium, no matter how old. He says the “spectrum shortage” in stadiums is just a myth.

With the new stadium still undergoing construction, it was too early for me to test anything resembling Santa Clara Stadium’s planned Wi-Fi network. For what it’s worth, I was able to connect to the 49ers’ guest Wi-Fi in their offices with no password, and no problems.

The 2.4GHz problem

There is one factor preventing better stadium Wi-Fi that even the 49ers may not be able to solve, however. Wi-Fi works on both the 2.4GHz and 5GHz bands. Generally, 5GHz is better because it offers more powerful signals, less crowded airwaves and more non-overlapping channels that can be devoted to Wi-Fi use.

The 2.4GHz band has 11 channels overall and only three that don’t overlap with each other. By using somewhat unconventionally small 20MHz channels in the 5GHz range, the 49ers will be able to use about eight non-overlapping channels. That’s despite building an outdoor stadium, which is more restricted than indoor stadiums due to federal requirements meant to prevent interference with systems like radar.

Each 49ers access point will be configured to offer service on one channel, and access points that are right next to each other would use different channels to prevent interference. So even if you’re surrounding fans with access points, as the 49ers plan to, they won’t interfere with each other.

But what if most users’ devices are only capable of connecting to the limited and crowded 2.4GHz band? Enterasys said 80 percent of Patriots fans connecting to Wi-Fi this past season did so from devices supporting only the 2.4GHz band, and not the 5GHz one.

“You have to solve 2.4 right now to have a successful high-density public Wi-Fi,” Brams said.

The iPhone 5 and newer Android phones and tablets do support both the 2.4GHz and 5GHz bands, however. Williams said by the time Santa Clara Stadium opens in 2014, he expects 5GHz-capable devices to be in much wider use.

When asked if the 49ers would be able to support 100 percent of fans if most of them can only connect to 2.4GHz, Williams showed a little less bravado.

“For those 2.4 users we will certainly design it so that there’s less interference,” he said. “It is a more dense environment if you are strictly constrained in 2.4, but we are not constrained in 2.4. We’re not trying to answer the 2.4 problem, because we have 5 available.”

“It’s 2013, we have another year and a half of iteration,” he also said. “We’ll probably be on, what, the iPhone 7 by then? The move to 5GHz really just makes us lucky. We’re doing this at the right time.”

Building a stadium in Facebook’s image

Williams and Malik both joined the 49ers last May. Malik was hired first, and then brought his old Facebook friend, Williams, on board. Malik had been the head of IT at Facebook, while Williams was the website’s first network engineer and later a director. They both left the site, basically because they felt there was nothing left to accomplish. Williams did some consulting, and Malik initially planned to take some time off.

Williams was a long-time 49ers season ticket holder, but that was far from the only thing that sold him on coming to the NFL.

“I had been looking for something challenging and fun again,” Williams said. “Once you go through an experience like Facebook, it’s really hard to find something that’s similar. When Kunal came to me, I remember it like it was yesterday. He said, ‘If you’re looking for something like Facebook you’re not going to find it. Here’s a challenge.'”

“This is an opportunity to change the way the world consumes live sports in a stadium,” Malik said. “The technology problems live sports has today are unsolved and no one has ever done what we are attempting to do here. That’s what gets me out of bed every day.”

Williams and Malik have built the 49ers’ network in Facebook’s image. That means each service—Wi-Fi, point-of-sale, IPTV, etc.—gets its own autonomous domain, a different physical switching system to provide it bandwidth. That way, problems or slowdowns in one service do not affect another one.

“It’s tribal knowledge that’s only developed within large content providers, your Facebooks, your Googles, your Microsofts,” Williams said. “You’ll see the likes of these large content providers build a different network that is based on building blocks, where you can scale vertically as well as horizontally with open protocols and not proprietary protocols.

“This design philosophy is common within the content provider space but has yet to be applied to stadiums or venues. We are taking a design we have used in the past, and we are applying it here, which makes sense because there is a ton of content. I would say stadium networks are 10 years behind. It’s fun for us to be able to apply what we learned [at Facebook].”

The 49ers are still evaluating what Wi-Fi equipment they will use. The products available today would suit them fine, but by late 2014 there will likely be stadium-class access points capable of using the brand-new 802.11ac protocol, which allows greater throughput in the 5GHz range than the widely used 802.11n. 11ac consumer devices are rare today, but the 49ers will use 802.11ac access points to future-proof the stadium if appropriate gear is available. 11ac is backwards compatible with 11n, so supporting the new protocol doesn’t leave anyone out—the 49ers also plan to support previous standards such as 11a, 11b, and 11g.

802.11ac won’t really become crucial until 802.11n’s 5GHz capabilities are exhausted, said Daren Dulac, director of business development and technology alliances at Enterasys.

“Once we get into 5GHz, there’s so much more capacity there that 11ac doesn’t even become relevant until we’ve reached capacity in the 5GHz range,” he said. “We really think planning for growth right now in 5GHz is acceptable practice for the next couple of years.”

Santa Clara Stadium network construction is expected to begin in Q1 2014. Many miles of cabling will support the “zero to 1,500” access points, which connect back to 48 server closets or mini-data centers in the stadium that in turn tie back to the main data center.

“Based on service type you plug into your specific switch,” Williams said. “If you’re IPTV, you’re in an IPTV switch, if you’re Wi-Fi you’re in a Wi-Fi switch. If you’re in POS [point-of-sale], you’re in a POS switch. It will come down to a Wi-Fi cluster, an IPTV cluster, a POS cluster, all autonomous domains that are then aggregated by a very large fabric, that allows them to communicate lots of bandwidth throughput, and allows them to communicate to the Internet.”

Whereas Candlestick Park’s network uses Layer 2 bridging—with all of the Wi-Fi nodes essentially on a single LAN— Santa Clara Stadium will rely on Layer 3 IP routing, turning the stadium itself into an Internet-like network. “We will be Layer 3 driven, which means we do not have the issue of bridge loops, spanning tree problems, etc.,” Williams said.

Keeping the network running smoothly

Wireless networks should be closely watched during games to identify interference from any unauthorized devices and identify usage trends that might result in changes to access points. At the Patriots’ Gillette Stadium, management tools show bandwidth usage, the number of fans connected to each access point, and even what types of devices they’re using (iPhone, Android, etc.) If an access point was overloaded by fans, network managers would get an alert. Altering radio power, changing antenna tilt, or adding radios may be required, but generally any major changes are made between games.

Enlarge / Dashboard view of Patriots’ in-game connectivity.
Enterasys

“In terms of real-time correction, it depends on what the event is,” said John Burke, a senior architect at Enterasys. “Realistically, some of these APs are overhead. If an access point legitimately went down and it’s on the catwalk above 300 [the balcony sections] you’re not going to fix that in the game. That’s something that would have to wait.”

So far, the Patriots’ capacity has been enough. Fans have yet to overwhelm a single access point. Even if they did, there is some overlap among access points, allowing fans to get on in case one AP is overloaded (or just broken).

The 49ers will use similar management tools to watch network usage and adjust access point settings in real time during games. “We expect to overbuild and actually play with things throughout,” Williams said. “Though we are building the environment to support 100 percent capacity, we do not expect 100 percent capacity to be used, so we believe we will be able to move resources around as needed [during each game].”

The same sorts of security protections in place in New England will be used in Santa Clara. Business systems will be password-protected and encrypted, and there will be encrypted tunnels between access points and the back-end network. While that level of protection won’t extend to the public network, fans shouldn’t be able to attack each other, because peer-to-peer connections will not be allowed.

What if the worst happens and the power goes out? During the Super Bowl’s infamous power outage, Wi-Fi did stay on for at least a while. Williams and Malik acknowledged that no system is perfect, but they said that they plan for Wi-Fi uptime even if power is lost.

“We have generators in place, and we’ll have UPS systems, so from a communications standpoint our plan is to keep all the communication infrastructure up and online [during outages],” Williams said. “But all of this stuff is man-made.”

A small team that does it all

Believe it or not, the 49ers have a tech team of less than 10 people, yet the organization is designing and building everything itself. Sports teams often outsource network building to carriers or equipment vendors, but not the 49ers. Besides building its own Wi-Fi network, the team will build a carrier-neutral distributed antenna system to boost cellular signals within the stadium.

“We are control freaks,” Williams said with a laugh. He explained that doing everything themselves makes it easier to track down problems, accept responsibility, and fix things. They also feel the need to take ownership of the project because none of the existing networks in the rest of the league approach what they want to achieve. There is a lot of low-hanging fruit just from solving the easy problems other franchises haven’t addressed, they think.Not all the hardware must be in-house, though. The 49ers will use cloud services like Amazon’s Elastic Compute Cloud when it makes sense.

“Let’s say we want to integrate a POS system with ordering,” Malik said. “If you have an app that lets you order food, and there’s a point of sale system, all the APIs and integration need to sit in the cloud. There’s no reason for it to sit in our data center.”

There are cases where the cloud is clearly not appropriate, though. Say the team captures video on site and distributes it to fans’ devices—pushing that video to a faraway cloud data center in the middle of that process would slow things down dramatically. And ultimately, the 49ers have a greater vision than just providing Wi-Fi to fans.

When I toured a preview center meant to show off the stadium experience to potential ticket buyers, a mockup luxury suite had an iPad embedded in the wall with a custom application for controlling a projector. That provides a hint of what the 49ers might provide.

“Our view is whatever you have at home you should have in your suite,” Williams said. “If that means there’s an iPad on the wall or an application you can use, hopefully that’s available. Your life should be much easier in this stadium.”

And whatever applications are built should be cross-platform. As Malik said, the 49ers are moving away from proprietary technologies to standards-based systems so they can provide nifty mobile features to fans regardless of what device they use.

Williams and Malik are already working long hours, and their jobs will get even more time-intensive when network construction actually begins. But they wouldn’t have it any other way—particularly the longtime season ticket holder Williams.

When work is “tied to something that you love deeply, which is sports, and tied to your favorite team in the world, that’s awesome,” Williams said. “I’m crazy about it, man. I get super passionate.”

Source:  arstechnica.com

Super Bowl plans to handle 30,000 Wi-Fi users at once—and sniff out “rogue devices”

Saturday, February 2nd, 2013

When 73,208 fans file into the New Orleans Superdome for the Super Bowl on Sunday, they’ll have to follow the usual rules: no booze, no weapons, no fireworks, and no food (though food and beer can be purchased inside the stadium at exorbitant rates).

They’ll also be prevented from bringing in any wireless equipment that might interfere with the proper workings of the Superdome Wi-Fi network. Lots of time and money went into giving ticket holders a wireless connection that rivals the one in their living rooms, and the NFL doesn’t want anyone messing it up.

“The NFL has a very robust frequency coordination solution in place,” Dave Stewart, director of IT and production for Superdome management firm SMG, told me in a phone interview. “Every device that enters the building has to go through a frequency scan and be authorized to enter. At the perimeter the devices are identified and tagged. If they present a potential for interference, they are remediated at that moment. Either the channel is changed or it is denied access. It’s all stopped at the perimeter for this event.”

In Stewart’s words, the goal is to prevent any “rogue access points or rogue equipment from attempting to operate in the same frequency” as the stadium Wi-Fi network (“rogue” as in “not under the control of the system administrators”).

It’s hard to imagine fans, press, or stadium staff deliberately trying to sabotage Super Bowl Wi-Fi, but some may do so unintentionally. Interference can be produced by “everything from someone operating a network wireless camera to someone operating pyrotechnics equipment that utilizes wireless service to trigger their equipment,” Stewart said. “Imagine if you were to bring in a wireless camera and that wireless camera is tuned to the 2.4GHz frequency range [also used by Wi-Fi] and is continually broadcasting a signal. Anything that’s going to operate in the same frequency range has the potential to cause interference. Some of those interfering devices are minimal, but others are impactful.”

The biggest concern, he said, comes from “non-Wi-Fi-compliant continuous broadcast devices such as wireless cameras.”

The best defense against such “rogue” wireless networking is to prevent the wrong devices from coming into the stadium, but you can’t stop everything. “You can’t stop a laptop from coming in. Working press needs to use that,” he said. Yet laptops can be problematic if their owners try to create their own private Wi-Fi networks. “Anyone who enters the facility with a laptop has the ability to become a rogue by going to ad hoc [wireless networking] mode,” Stewart said.

That’s why wireless security doesn’t stop when the game starts; the Superdome will use spectral analysis equipment to detect interference. “We’re always monitoring the network. So we have a plan in place if there is an interfering signal to identify that and remediate that problem,” Stewart said.

So if you’re broadcasting a rogue wireless signal, well, you might just get a tap on the shoulder from a Superdome employee. Isn’t it more fun just to watch the game, anyway?

Is the TV timeout over yet?

Well, maybe not. The NFL manages to spread 60 minutes of clock time across three hours in a typical game. What with time running off the clock between plays and the typical play lasting about four seconds, an average game ends up with only 11 minutes of action. And given how long Super Bowl halftime shows last, the game might not be over till Monday.

So fans have plenty of time to check their e-mail, upload pictures to Facebook, or get instant replays and game-related information on their mobile devices. While the NFL’s strict control over wireless equipment might sound draconian, it’s in service of the greater good: Wi-Fi for everyone who wants it.

The Superdome already had one of the most robust cellular networks among football stadiums, because 18 months ago AT&T built a carrier-neutral distributed antenna system on site to boost mobile signals. But that wasn’t enough. Cellular providers want Wi-Fi in places like the Superdome because it offloads traffic from the cellular network, and fans like it because they’re less likely to drop their connections or wait for videos to buffer.

The Superdome (or the Mercedes-Benz Superdome, to get the branding right) previously had Wi-Fi—but only for staff, press, and systems like ticketing. “That was not getting us where the NFL wanted us to be relative to the Super Bowl needs,” said Superdome General Manager Alan Freeman. The new, Super Bowl-scale Wi-Fi network was just put in this season, with trial runs in a couple of late-season Saints games and in the Sugar Bowl. The Super Bowl will be the first time the network is publicly advertised as available to all fans, so the load will be greater. No password will be required to get on the Wi-Fi network.

More than 700 wireless access points will distribute signals inside the Superdome. Another 250 access points will provide Wi-Fi outside the stadium, including in parking lots and in Champions Square. (Another 300 access points are in the adjacent New Orleans Arena, which hosts the city’s pro basketball team.)

During the Super Bowl, the network will be able to handle up to 30,000 simultaneous connections, which should be enough. At last year’s Super Bowl in Indianapolis, Wi-Fi from 604 access points supported 8,260 simultaneous connections at its peak, while 12,946 attendees were on the Wi-Fi at some point during the game. 225GB of data was downloaded and 145GB uploaded, with peaks of 75Mbps down and 42Mbps up. (We’re told the cell network for all carriers at last year’s Super Bowl handled another 560GB of data total, including downloads and uploads.) Usage is expected to be higher this year, but it’s impossible to predict exactly how much it will increase.

Superdome management thinks it’s ready. In testing, “We’re constantly seeing 20Mbps up and 20 megs down in all areas of the building,” Stewart said. “That, of course, will change depending on the load, but the system is backed up by multiple redundant links to the Internet.”

Verizon Wireless built the Wi-Fi network, and all equipment used came from Cisco. The back-end of the network is handled by two Cisco Nexus 7000 Series Switches (with another two in the adjacent arena), Cisco 5500 Series Wireless Controllers, and Cisco’s 5540 Adaptive Security Appliances. Access points are Cisco Aironet 3500 devices.

This isn’t consumer gear (a business Cisco is getting out of); these are high-density access points, designed for stadiums, with directional antennas that send the signals to just the right places. The Superdome has a ceiling, of course, but it’s far above fans’ heads. If antennas weren’t positioned correctly, signals could be wasted in all that empty air. Using directional antennas lets the Superdome “control the signal and have a seamless handoff from one section to another when a fan roams, or when someone comes online,” Stewart noted.

We need more channels!

The network supports 802.11n and previous Wi-Fi protocols 802.11a, b, and g, using both the 2.4GHz and 5GHz bands. Unfortunately, many fans’ devices are capable only of getting on 2.4GHz.

The 2.4GHz band has 11 channels that can be used for Wi-Fi in North America, but because the channels overlap, the Superdome uses just channels 1, 6, and 11. In the 5GHz band, with its 23 non-overlapping channels, the Superdome network can use just about every available channel (while making sure not to interfere with radar).

High-end mobile devices like the iPad, iPhone 5, and Samsung Galaxy S III support 5GHz. Newer versions of the Kindle Fire support 5GHz, too; Google’s Nexus 7 Android tablet does not. Many phones are still stuck on 2.4GHz as well.

“We’re very anxious and can’t wait for everyone to get on 5GHz,” Stewart said. Even better will be when the world moves on to 802.11ac networks and devices, because the next-generation protocol uses multi-user MIMO (multiple-input/multiple-output) to transmit signals more efficiently. But that’s not happening soon. While some home routers support 802.11ac, they’re not NFL caliber.

“There’s no commercially available high-density 802.11ac equipment that I know of,” Stewart said.

In a worst-case scenario, high numbers of fans streaming video could cause congestion and slow down fans’ connections. “This is not unlimited. There’s no such thing,” said Kelley Carr, co-founder of Cellular Specialities, a consultant who helped oversee the design and implementation of the network for the big game.

What they have for the Super Bowl is probably good enough for this year, though. “We’re all confident it will work, just based on our experience in the past,” said Carr. “As long as 100 percent of the people in there don’t take out their cellular device and switch it to the Wi-Fi network, it should be fine.”

With an average signal strength rating of -60dB, fans in their seats should get a signal comparable to what they would have at home if they were sitting about 20 feet from their wireless router, Stewart said.

This will be the seventh Super Bowl to be hosted at the Superdome since 1978—and such access would have been unthinkable in any of the previous games. Freeman noted that “from a technological perspective, these mega-events keep getting more complex, exponentially in some cases, every year.”

Source:  arstechnica.com

Cisco accelerates Wi-Fi with Aironet 3600

Thursday, January 31st, 2013

Cisco (NASDAQ:CSCO) is updating its WLAN portfolio today with a new flagship Aironet access point. The Aironet 3600 is a three spatial stream device with a simultaneous 2.4 and 5 GHz, 4×4 antenna design. The total theoretical speed of the access point comes in at 900 Mbps.

Specified speed alone doesn’t define the true capabilities of any Wi-Fi access point as things such as reach and signal integrity often are more important to end-users in an enterprise deployment.

“The cool thing about the extra fourth antenna is that we have a degree for redundancy that lets us speed up the slower clients,” Sylvia Hooks, senior manager, wireless solutions at Cisco.”We’re able to speed mobile devices that need speeding up and there is no special software or standards required on the client side.”

Hooks explained that the Aironet 3600 has four transmit and receive antennas that allow for more consistent upload speeds. The need for more consistent speeds is important to help consumer-grade devices like tablets that don’t have strong transmit power capabilities.

“So even if the signal is weak from the mobile device, we’re able to compensate,” Hooks said. “On the reverse side, when we get a signal from a mobile client, we’re able to calculate its location and then send back to that exact location using beamforming.”

She added that with the power to get stronger signals out to individual mobile devices, the access point is able to serve even more users, increasing the overall system capacity.  Aironet 3600 users can also roam farther than before.  Users can go up to 130 feet away from the access point without dropping down to a slower speed.  The integrity of the signal is further protected with Cisco’s Clean Air technology that analyses the wireless spectrum for potential interference.  Clean Air was first deployed by Cisco in 2010 on the Aironet 3500 series access points.

With the Aironet 3600, Cisco is also introducing support for the IEEE 802.11r standard which specifies Fast Roaming for wireless clients.

“It’s a standard that defines how clients roam between access points on the same network, fast enough so there aren’t any delays or lost connections,” Hooks said.

Another standard that is likely of interest to enterprise buyers is the emerging 802.11ac standard for gigabit Wi-Fi. Currently 802.11ac chip technology is mostly at the consumer-level, according to Hooks. That said, she didn’t rule out the future possibility that the Aironet 3600 could get an upgrade.

“We haven’t defined additional modules yet to snap into this access point although it does have the ability to snap in a totally new radio,” Hooks said. “At this time, Cisco hasn’t formally announced any plans but the intention of the platform is that it is modular enough to accept new technologies.”

Source:  wi-fiplanet.com