When professors at the University of Ottawa realized that just a few students accessing video from smartphones and tablets killed performance on the wireless network, the university's IT team challenged its wireless vendor Aruba Networks to come up with a mobile application delivery solution. That solution would have to enable dense groups of students to simultaneously access bandwidth-hungry apps like video without a problem.
The University of Ottawa's issue is common as universities and large enterprises have a growing number of users with personal smartphones and tablets overburdening legacy wireless LANs. Users of these devices tend to congregate into high-density groups; they rarely plug into Ethernet and they stream multimedia applications constantly.
"Most of these wireless networks were initially designed for access," said Brad Noblet, chairman of the Multimedia-Grade Wi-Fi Working Group, a consortium of vendors and end-user organizations working to define requirements for multimedia mobile application delivery on Wi-Fi. "There wasn't a lot of thought that went into planning how one would scale the number of users, particularly in lecture halls, conference rooms and auditoriums. No one thought they'd have to deal with 100 to 500 connected people all clustered together."
What's more, network managers have been taken off guard by bandwidth-hungry multimedia applications running on wireless LAN. Legacy networks are designed for accessing email, webpages and PowerPoint presentations. "Now they are dealing with real-time video conferencing and on-demand streaming video. [Network managers] are pulling their hair out because these networks don't scale," Noblet said.
Video over Wi-Fi, user density present mobile application delivery nightmare
The higher education sector must overcome these challenges rapidly as professors increasingly rely on educational applications that stream video over Wi-Fi to student devices in the classroom.
At the University of Ottawa, professors quickly learned that all it took was four to six students accessing media streams to rapidly degrade wireless LAN performance, said Pierre Lalonde, assistant director of communications and computing at the university.
The university has a legacy 802.11a/b/g Aruba-based network that can't handle the increased demands of mobile application delivery, Lalonde explained. Video over Wi-Fi is itself a challenge, but the density of wireless users is also exploding.
"The popularity of wireless has grown beyond what we expected when we first deployed," Lalonde said. "In the beginning we would have one device for every two users [in a classroom]. Now what we see is each person coming in with two wireless devices that are connected to the network. They have their small handheld device and they also have a laptop with them."
Application fingerprinting, band steering, load balancing for mobile app delivery
Aruba agreed to build a demo network for mobile application delivery to a high concentration of users, and IT staff at the university certified the results. The vendor deployed four 802.11n wireless LAN access points—the AP 135—in a University of Ottawa classroom and connected them to the company's new S35000 Mobility Access Switch and its M3 controller. Aruba then delivered six different multimedia educational applications to 100 iPads that were connected to the network. Aruba's Adaptive Radio Management feature load balanced the connections for each of the iPads, so that the tablets didn't flood a single access point with connection requests.
Aruba then hit the network with data traffic generated by test equipment and used the application fingerprinting capabilities of its MOVE architecture to prioritize traffic from the multimedia education applications, according to Robert Fenstermacher, Aruba's head of education solutions marketing. With all of the iPads streaming video applications, engineers launched a peer-to-peer video chat between two of the iPads via FaceTime. The network was able to enforce policy that prioritized traffic for the FaceTime video chat over traffic from the streaming video.
"Aruba demoed [quality of service] for FaceTime as it was running on top of 98 video streams that were already streaming data to the other iPads,” said Noblet, who also observed the demo. "They had programmed the controller to fingerprint applications based on protocols and prioritize FaceTime traffic over other streaming video traffic to make sure that that [peer-to-peer] application didn't get interrupted," he said.
Another key element of Aruba's success with the demo was simply raw throughput capabilities. Several vendors, including Aruba, HP Networking, Cisco Systems and Meru Networks have launched high-end, 802.11n-based access points with multiple radios that use MIMO technology to deliver an aggregate throughput of 450 Mbps. These powerful access points are capable of serving high-density groups of users. Then it's up to the individual vendors to engineer the smarts required for multimedia mobile application delivery.
Lalonde said his university is preparing an RFP process for a wireless LAN upgrade now that his staff has seen the successful demonstration from Aruba.
"Now going forward we see there are even more possibilities for [mobile application delivery]," Lalonde said. "We recognize the ability to do telephony over Wi-Fi with 802.11n. This definitely gives us more confidence in terms of not having jitter [with multimedia applications] and being able to roam as well."
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