Wireless to the Nth Degree: Wireless Access Points That Utilize the 802.11n Standard Offer Superfast Speeds and Can Simultaneously Support a Multitude of Bandwidth-Hogging Devices
Michelle Fredette · T.H.E. Journal Technological Horizons in Education · 2011
WHEN WASHINGTON'S Bremerton School District considered running an iPad-based reading pilot in one of its elementary schools, the IT department was forced to confront the grim reality of its wireless network--and it wasn't a very pretty picture. We did have a wireless network, but it was kind of a means to an end--an early solution that we had had problems with, says Steve Bartlett, technology supervisor for the district. example, we couldn't connect more than 10 to 12 devices to an access point before we had problems with authentication, latency, and speed. [ILLUSTRATION OMITTED] For many schools, the benefits offered by enhanced technology in the classroom are balanced by an equivalent number of hurdles, from budget to buy-in to technical issues. Bartlett and his IT department of five over-came the budget and backing hurdles when the district hired a new school superintendent with a strong focus on technology. the superintendent's expectations clearly communicated, it was very easy for us to move forward, rearrange budget priorities, and make it happen, Bartlett says. As for concerns about technical issues such as support, coverage, and security, they learned that a new wireless technology--specifically 802.11n-capable wireless access point technology--would have many of the solutions. Faster Speeds, Increased Coverage With a data rate of up to 600 megabits per second, 802.11n-standard access points (APs) achieve speeds up to six times that of their predecessors, 802.11a, b, or g, and they can support 50 to 100 client connections at once, even if those clients are using bandwidthintensive applications that stream video or deliver voice over wireless LAN. They also incorporate MIMO (multiple-input, multiple-output) antenna systems that can bounce radio waves off walls and other obstacles, reaching the desired receiving device from various different paths, or spatial streams. Among other things, MIMO enables faster transmission and wireless access in places that previously were hard to penetrate with earlier wireless technology. The 802.11n technology also incorporates a new, third spatial stream, which Kevin Secino, global product marketing manager for mobility at HP, compared to the opening of a third lane on a highway. You get more traffic through three lanes than two, he explains. You can think of this technology in a similar fashion. We're automatically able to transmit more data through three streams than two. The three-stream technology is also completely compatible with one and two spatial streams, as well as a, b, and g technology. Band steering, a common feature of most access-point devices, helps to keep traffic flowing smoothly on all three spatial streams. Band steering is the process by which an AP detects when a client device is n capable and steers that device onto the 802.11n streams so legacy devices can use the 802.11a, b, and g streams. Also included in many vendors' 802.11n AP technology is beamforming, which optimizes the link between clients and APs by reducing power usage and interference, enabling APs to operate at stronger signal strengths. helps you get higher throughput for further distances, because it's concentrating the energy toward your device, rather than sending the energy everywhere, explains Jeff Schwartz, HP's global product manager for mobility. Beamforming enables the access points, which usually contain three transmitters, to time transmissions so packets arrive at their destination at exactly the same time. With previous technology, Schwartz says, the three radios would transmit, and traffic from one would arrive slightly before traffic from another because they took different paths. There can be a downside, however. Beamforming relies on a signal exchange between the access point and the receiving device, which can be less effective if a device is moving around and the signal has to be repeatedly reset. …