Wireless Technology and Mobility
K-12 school systems across the United States are jumping on the wireless networking bandwagon. Some of these schools and school districts include Beaufort County, SC, Campbell Union High School in Silicon Valley, several schools in Georgia, Pine Crest School, Fort Lauderdale, FL, and Lac qui Parle Valley School District in Minnesota. One of the bonuses of creating a wireless network infrastructure instead of a wired network infrastructure is that the technology specialists do not have to knock down walls which can be very expensive and time-consuming. Many times schools like Campbell Union High School, which is over 100 years old, might contain asbestos and rooting around in walls might disturb this cancer causing substance that is in many older schools. Another plus to wireless is that typically it is less expensive and much more cost effective to install several access points throughout a school with wireless cards in computers, than to wire the entire school.
Currently there are two wireless technologies that conform to the Industry of Electrical and Electronic Engineering (IEEE) standards and that are in current main stream production. The most prevalent technology is 802.11b which is also called Wi-Fi. This technology works at the 2.4 GHz frequency, can reach speeds of 11 Mbps, and has a maximum optimal range of around 300 feet. Hot spots, areas where you can connect to the Internet wirelessly, are popping up all over in coffee shops and airports around the country. These areas give consumers the opportunity to log on to the Internet using their mobile device usually for a small fee. Some of the downsides of this technology include interference from other products that use the 2.4 GHz frequency like cordless phones and baby monitors. Another negative is that 802.11b is not a switched technology like 802.11a but is a hub technology. When users log on to an 802.11b access point, they are using up the bandwidth of other users who are also logged on to the same access point and this can definitely lead to slower speeds. Many school administrators are shying away from the 802.11b technology because they feel that multimedia applications and file sizes are going to be too large to display correctly on a system that is limited to a maximum of 11 Mbps, but more realistically operates at 6 to 7 Mbps. Schools are also finding out that they need to place access points around every 60 meters or one access point for every five classrooms. This enables 10 students at a time to use the service effectively without long lags.
The 802.11a specification, also known as Wi-Fi 5, can reach speeds up to 5 times faster than 802.11b (54 Mbps), has three times the range of 802.11b, operates at the 5 GHz frequency, and is much more robust because the sine wave dimensions are not as likely to be interfered with as 802.11b technology. Bluetooth is another wireless technology but it has a range of only about 30 feet and is used more to connect peripherals without using cables.
One of the problems when choosing one of these technologies is that 802.11a is not backwards compatible with 802.11b. This means that if you wanted to use both you would need two separate cards with two different access points (although I have seen a Linksys dual-band router on the market and hopefully this is the direction the industry will head). Another standard is on the horizon, and it is cleverly named 802.11g. The 802.11g technology will operate at the 2.4 GHz frequency and be backwards compatible with 802.11b, while at the same time equaling the speed and robustness of the 802.11a specification.
There is another technology that was created in Huntsville, AL called Ultra Wide Band (UWB). UWB uses electrical impulses instead of sine waves to transmit data. The FCC has given the go ahead for limited commercial use of this technology but without the IEEE standards, which act as a stamp of approval for commercial manufacturers; this technology might have a tough time taking off. UWB uses a broad range of the airwaves and emits millions of pulses each second. However, these electrical pulses do not use much energy and therefore do not cause interference with other signals. This technology can pinpoint locations through walls and send data at very high speeds.
At the same time, some analysts are predicting that bandwidth or network capacity will continue to outgrow processor power, memory and storage. This will inevitably lead to a more centralized network, where we have thin clients instead of machines with hard drives. This would be ideals for schools because the security, and administration would mainly take place at one location and the thin clients would be much less expensive than today’s computer. More info can be found at these links:
Selected Resources
http://www.vartek.com/documents/eschool_news_special_report.htm
http://www.intel.com/education/teachtech/learning/casestudies/going_wireless.htm
http://techupdate.zdnet.com/techupdate/stories/main/0,14179,2885192,00.html