Posts Tagged ‘802.11a’

Next up for WiFi

Thursday, August 22nd, 2013

Transitioning from the Wi-Fi-shy financial industry, Riverside Medical Center’s CSO Erik Devine remembers his shock at the healthcare industry’s wide embrace of the technology when he joined the hospital in 2011.

“In banking, Wi-Fi was almost a no-go because everything is so overly regulated. Wireless here is almost as critical as wired,” Devine still marvels. “It’s used for connectivity to heart pumps, defibrillators, nurse voice over IP call systems, surgery robots, remote stroke consultation systems, patient/guest access and more.”

To illustrate the level of dependence the organization has on Wi-Fi, Riverside Medical Center calls codes over the PA system — much like in medical emergencies — when the network goes down. “Wireless is such a multifaceted part of the network that it’s truly a big deal,” he says.

And getting bigger. Besides the fact that organizations are finding new ways to leverage Wi-Fi, workers have tasted the freedom of wireless, have benefited from the productivity boost, and are demanding increased range and better performance, particularly now that many are showing up with their own devices (the whole bring your own device thing). The industry is responding in kind, introducing new products and technologies, including gigabit Wi-Fi (see “Getting ready for gigabit Wi-Fi“), and it is up to IT to orchestrate this new mobile symphony.

“Traffic from wireless and mobile devices will exceed traffic from wired devices by 2017,” according to the Cisco Visual Networking Index. While only about a quarter of consumer IP traffic originated from non-PC devices in 2012, non-PC devices will account for almost half of consumer IP traffic by 2017, Cisco says.

Cisco Visual Networking IndexIT gets it, says Tony Hernandez, principal in Grant Thornton’s business consulting practice. Wi-Fi is no longer an afterthought in IT build-outs. “The average office worker still might have a wired connection, but they also have the capability to use Wi-Fi across the enterprise,” says Hernandez, noting the shift has happened fast.

“Five years ago, a lot of enterprises were looking at Wi-Fi for common areas such as lobbies and cafeterias and put that traffic on an isolated segment of the network,” Hernandez says. “If users wanted access to corporate resources from wireless, they’d have to use a VPN.”

Hernandez credits several advances for Wi-Fi’s improved stature: enterprise-grade security; sophisticated, software-based controllers; and integrated network management.

Also in the mix: pressure from users who want mobility and flexibility for their corporate machines as well as the ability to access the network from their own devices, including smartphones, tablets and laptops.

Where some businesses have only recently converted to 802.11n from the not-too-distant past of 802.11a/b/g, they now have to decide if their next Wi-Fi purchases will support 802.11ac, the draft IEEE standard that addresses the need for gigabit speed. “The landscape is still 50/50 between 802.11g and 802.11n,” Hernandez says. “There are many businesses with older infrastructure that haven’t refreshed their Wi-Fi networks yet.”

What will push enterprises to move to 802.11ac? Heavier reliance on mobile access to video such as videoconferencing and video streaming, he says.

Crash of the downloads

David Heckaman, vice president of technology development at luxury hospitality chain Mandarin Oriental Hotel Group, remembers the exact moment he knew Wi-Fi had gained an equal footing with wired infrastructure in his industry.A company had booked meeting room space at one of Mandarin Oriental’s 30 global properties to launch its new mobile app and answered all the hotel’s usual questions about anticipated network capacity demands. Not yet familiar with the impact of dense mobile usage, the IT team didn’t account for the fallout when the 200-plus crowd received free Apple iPads to immediately download and launch the new app. The network crashed. “It was a slap in the face: What was good enough before wouldn’t work. This was a whole new world,” Heckaman says.

Seven to eight years ago, Wi-Fi networks were designed to address coverage and capacity wasn’t given much thought. When Mandarin Oriental opened its New York City property in 2003, for example, IT installed two or three wireless access points in a closet on each floor and used a distributed antenna to extend coverage to the whole floor. At the time, wireless only made up 10% of total network usage. As the number climbed to 40%, capacity issues cropped up, forcing IT to rethink the entire architecture.

“We didn’t really know what capacity needs were until the Apple iPhone was released,” Heckaman says. Now, although a single access point could provide signal coverage for every five rooms, the hotel is putting access points in almost every room to connect back to an on-site controller.

Heckaman’s next plan involves adding centralized Wi-Fi control from headquarters for advanced reporting and policy management. Instead of simply reporting that on-site controllers delivered a certain number of sessions and supported X amount of overall bandwidth, he would be able to evaluate in real-time actual end-device performance. “We would be able to report on the quality of the connection and make adjustments accordingly,” he says.

Where he pinpoints service degradation, he’ll refresh access points with those that are 802.11ac-enabled. As guests bring more and more devices into their rooms and individually stream movies, play games or perform other bandwidth-intensive actions, he predicts the need for 802.11ac will come faster than anticipated.

“We have to make sure that the physical link out of the building, not the guest room access point, remains the weakest point and that the overall network is robust enough to handle it,” he says.

Getting schooled on wireless

Craig Canevit, IT administrator at the University of Tennessee at Knoxville, has had many aha! moments when it comes to Wi-Fi across the 27,000-student campus. For instance, when the team first engineered classrooms for wireless, it was difficult to predict demand. Certain professors would need higher capacity for their lectures than others, so IT would accommodate them. If those professors got reassigned to different rooms the next year, they would immediately notice performance issues.

“They had delays and interruption of service so we had to go back and redesign all classrooms with more access points and more capacity,” Canevit says.

The university also has struggled with the fact that students and faculty are now showing up with numerous devices. “We see at least three devices per person, including smartphones, tablets, gaming consoles, Apple TV and more,” he says. IT has the dual challenge of supporting the education enterprise during the day and residential demands at night.

The school’s primary issue has revolved around IP addresses, which the university found itself low on as device count skyrocketed. “Devices require IP addresses even when sitting in your pocket and we faced a terrible IP management issue,” he says. IT had to constantly scour the network for unused IP addresses to “feed the monster.”

Eventually the team came too close to capacity for comfort and had to act. Canevit didn’t think IPv6 was widely enough supported at the time, so the school went with Network Address Translation instead, hiding private IP addresses behind a single public address. A side effect of NAT is that mapping network and security issues to specific devices becomes more challenging, but Canevit says the effort is worth it.

Looking forward, the university faces the ongoing challenge of providing Wi-Fi coverage to every dorm room and classroom. That’s a bigger problem than capacity. “We only give 100Mbps on the wired network in residence halls and don’t come close to hitting capacity,” he says, so 802.11ac is really not on the drawing board. What’s more, 802.11ac would exacerbate his coverage problem. “To get 1Gbps, you’ll have to do channel bonding, which leaves fewer overlapping channels available and takes away from the density,” he says.

What he is intrigued by is software-defined networking. Students want to use their iPhone to control their Apple TV and other such devices, which is impossible currently because of subnets. “If you allowed this in a dorm, it would degrade quality for everyone,” he says. SDN could give wireless administrators a way around the problem by making it possible to add boatloads of virtual LANs. “Wireless will become more of a provisioning than an engineering issue,” Canevit predicts.

Hospital all-in with Wi-Fi

Armand Stansel, director of IT infrastructure at Houston’s The Methodist Hospital System, recalls a time when his biggest concern regarding Wi-Fi was making sure patient areas had access points. “That was in early 2000 when we were simply installing Internet hotspots for patients with laptops,” he says.

Today, the 1,600-bed, five-hospital system boasts 100% Wi-Fi coverage. Like Riverside Medical Center, The Methodist Hospital has integrated wireless deep into the clinical system to support medical devices such as IV pumps, portable imaging systems for radiology, physicians’ tablet-based consultations and more. The wireless network has 20,000 to 30,000 touches a day, which has doubled in the past few years, Stansel says.

And if IT has its way, that number will continue to ramp up. Stansel envisions a majority of employees working on the wireless network. He wants to transition back-office personnel to tablet-based docking systems when the devices are more “enterprise-ready” with better security and durability (battery life and the device itself).

Already he has been able to reduce wired capacity by more than half due to the rise of wireless. Patient rooms, which used to have numerous wired outlets, now only require a few for the wired patient phone and some telemetry devices.

When the hospital does a renovation or adds new space, Stansel spends as much time planning the wired plant as he does studying the implications for the Wi-Fi environment, looking at everything from what the walls are made of to possible sources of interference. And when it comes to even the simplest construction, such as moving a wall, he has to deploy a team to retest nearby access points. “Wireless does complicate things because you can’t leave access points static. But it’s such a necessity, we have to do it,” he says.

He also has to reassess his access point strategy on an ongoing basis, adding more or relocating others depending on demand and traffic patterns. “We always have to look at how the access point is interacting with devices. A smartphone connecting to Wi-Fi has different needs than a PC and we have to monitor that,” he says.

The Methodist Hospital takes advantage of a blend of 802.11b, .11g and .11n in the 2.4GHz and 5GHz spectrums. Channel bonding, he has found, poses challenges even for .11n, reducing the number of channels available for others. The higher the density, he says, the less likely he can take full advantage of .11n. He does use n for priority locations such as the ER, imaging, radiology and cardiology, where users require higher bandwidth.

Stansel is betting big that wireless will continue to grow. In fact, he believes that by 2015 it will surpass wired 3-to-1. “There may come a point where wired is unnecessary, but we’re just not there yet,” he says.

Turning on the ac

Stansel is, however, onboard with 802.11ac. The Methodist Hospital is an early adopter of Cisco’s 802.11ac wireless infrastructure. To start, he has targeted the same locations that receive 802.11n priority. If a patient has a cardiac catheterization procedure done, the physician who performed the procedure can interactively review the results with the patient and family while he is still in the recovery room, referencing dye images from a wireless device such as a tablet. Normally, physicians have to verbally brief patients just out of surgery, then do likewise with the family, and wait until later to go over high-definition images from a desktop.

Current wireless technologies have strained to support access to real-time 3D imaging (also referred to as 4D), ultrasounds and more. Stansel expects better performance as 802.11ac is slowly introduced.

Riverside Medical Center’s Devine is more cautious about deploying 802.11ac, saying he is still a bit skeptical. “Can we get broader coverage with fewer access points? Can we get greater range than with 802.11n? That’s what is important to us,” he says.

In the meantime, Devine plans to deploy 20% to 25% more access points to support triangulation for location of equipment. He’ll be able to replace RFID to stop high-value items such as Ascom wireless phones and heart pumps from walking out the door. “RFID is expensive and a whole other network to manage. If we can mimic what it does with Wi-Fi, we can streamline operations,” he says.

High-power access points currently are mounted in each hallway, but Devine wants to swap those out with low-power ones and put regular-strength access points in every room. If 802.11ac access points prove to be affordable, he’ll consider them, but won’t put off his immediate plans in favor of the technology.

The future of Wi-Fi

Enterprise Strategy Group Senior Analyst John Mazur says that Wi-Fi should be front and center in every IT executive’s plans. BYOD has tripled the number of Wi-Fi connected devices and new access points offer about five times the throughput and twice the range of legacy Wi-Fi access points. In other words, Mazur says, Wi-Fi is up to the bandwidth challenge.

He warns IT leaders not to be scared off by spending projections, which, according to ESG’s 2013 IT Spending Intentions Survey, will be at about 2012 levels and favor cost-cutting (like Devine’s plan to swap out RFID for Wi-Fi) rather than growth initiatives.

But now is the time, he says, to set the stage for 802.11ac, which is due to be ratified in 2014. “IT should require 802.11ac support from their vendors and get a commitment on the upgrade cost and terms before signing a deal. Chances are you won’t need 802.11ac’s additional bandwidth for a few years, but you shouldn’t be forced to do forklift upgrades/replacements of recent access points to get .11ac. It should be a relatively simple module or software upgrade to currently marketed access points.”

While 802.11ac isn’t even fully supported by wireless clients yet, Mazur recommends keeping your eye on the 802.11 sky. Another spec, 802.11ad, which operates in the 60GHz spectrum and is currently geared toward home entertainment connectivity and near-field HD video connectivity, could be — like other consumer Wi-Fi advances — entering the enterprise space sooner rather than later.

Source:  networkworld.com

Cheat sheet: What you need to know about 802.11ac

Friday, June 21st, 2013

Wi-Fi junkies, people addicted to streaming content, and Ethernet-cable haters are excited. There’s a new Wi-Fi protocol in town, and vendors are starting to push products based on the new standard out the door. It seems like a good time to meet 802.11ac, and see what all the excitement’s about.

What is 802.11ac?

802.11ac is a brand new, soon-to-be-ratified wireless networking standard under the IEEE 802.11 protocol. 802.11ac is the latest in a long line of protocols that started in 1999:

  • 802.11b provides up to 11 Mb/s per radio in the 2.4 GHz spectrum. (1999)
  • 802.11a provides up to 54 Mb/s per radio in the 5 GHz spectrum. (1999)
  • 802.11g provides up to 54 Mb/s per radio in the 2.4 GHz spectrum (2003).
  • 802.11n provides up to 600 Mb/s per radio in the 2.4 GHz and 5.0 GHz spectrum. (2009)
  • 802.11ac provides up to 1000 Mb/s (multi-station) or 500 Mb/s (single-station) in the 5.0 GHz spectrum. (2013?)

802.11ac is a significant jump in technology and data-carrying capabilities. The following slide compares specifications of the 802.11n (current protocol) specifications with the proposed specs for 802.11ac.

(Slide courtesy of Meru Networks)

What is new and improved with 802.11ac?

For those wanting to delve deeper into the inner workings of 802.11ac, this Cisco white paper should satisfy you. For those not so inclined, here’s a short description of each major improvement.

Larger bandwidth channels: Bandwidth channels are part and parcel to spread-spectrum technology. Larger channel sizes are beneficial, because they increase the rate at which data passes between two devices. 802.11n supports 20 MHz and 40 MHz channels. 802.11ac supports 20 MHz channels, 40 MHz channels, 80 MHz channels, and has optional support for 160 MHz channels.

(Slide courtesy of Cisco)

More spatial streams: Spatial streaming is the magic behind MIMO technology, allowing multiple signals to be transmitted simultaneously from one device using different antennas. 802.11n can handle up to four streams where 802.11ac bumps the number up to eight streams.

(Slide courtesy of Aruba)

MU-MIMO: Multi-user MIMO allows a single 802.11ac device to transmit independent data streams to multiple different stations at the same time.

(Slide courtesy of Aruba)

Beamforming: Beamforming is now standard. Nanotechnology allows the antennas and controlling circuitry to focus the transmitted RF signal only where it is needed, unlike the omnidirectional antennas people are used to.

(Slide courtesy of Altera.)

What’s to like?

It’s been four years since 802.11n was ratified; best guesses have 802.11ac being ratified by the end of 2013. Anticipated improvements are: better software, better radios, better antenna technology, and better packaging.

The improvement that has everyone charged up is the monstrous increase in data throughput. Theoretically, it puts Wi-Fi on par with gigabit wired connections. Even if it doesn’t, tested throughput is leaps and bounds above what 802.11b could muster back in 1999.

Another improvement that should be of interest is Multi-User MIMO. Before MU-MIMO, 802.11 radios could only talk to one client at a time. With MU-MIMO, two or more conversations can happen concurrently, reducing latency.

Source:  techrepublic.com