Traditionally, the technology required to permit mobility of the learning environment was not available in the Ethernet LAN days, and reconfiguring aging schools with Ethernet cable can be a costly and sometimes complex task. The cost of renovating and updating electrical, HVAC and sometimes removal or asbestos has often been cost prohibitive. With the advances that have been made in wireless technology over the past decade, wireless has become an easier and less cumbersome set-up in the classroom and provides outstanding mobility that enhances an interactive learning model.
The two main advantages of using wired connections over wirelessare speed and capacity. The speeds of wired connections range from 100 to1000Mbps (100 times faster than wireless). Since each machine hasits own connection, bandwidth is not shared, so that the connectionremains fast regardless of the number of users. Wired connections arealso extremely reliable, and provide the capacity needed when users are using multimedia tools with files that are more than 15 MB (too large for basic wireless networks to handle).
The biggest disadvantage to using wired networks is that it is not a mobile system because users are confined to areas where there is access to wired jacks. Ethernet cables will run up to 100 meters before they need to be boosted; however, the longer the cable, the more signal loss occurs. There are some newer cables that will prevent this from happening, but they are fairly expensive. Cables can also be affected by moisture or magnets, but again, there are new cables that are better shielded from interference and physical deterioration. However, these cables must run either between computers or from each computer to a central device. As a result, the installation is often costly, time consuming, and difficult if the cables must be run under the floors orthrough the walls. Some new office buildings have pre-wired CAT5 cables,but schools, unless they are extremely new, generally do not.
Wireless LAN networks give the classroom a feature common to many businesses in which the students’ wireless devices communicate with a central wired node on the LAN. This practical approach is in contrast to the peer-to-peer mode. The client-server structure, rather than equal peer-to-peer nodes that simultaneously function as both clients and servers to other nodes in the wireless network, is better suited to classroom applications. Centralized access to the Internet, local printers or other wired services through infrastructure mode wireless LAN connections to an access point is the most appropriate classroom set-up for signal strength, security, and network management. When the wireless client/student initiates the download/upload and the wired LAN server reacts to and satisfies these requests, and file transfers can be managed by the teacher and school administration.
Wireless routers for this set-up have dropped in price considerably over recent years and their reliability has improved greatly. Also, peer to peer systems do not permit quick and easy reconfigurations of multiple independent users, and security would be a nightmare if each device needed to be configured separately with any reconfiguration made to the classroom (e.g. if a new mode were added). Broadband routes for wireless service offer firewall capability built into the device and are configurable through its own software. Maintenance and upgrades are less expensive in the long run, and connection sharing software packages (ICS) are available with a nominal fee or free.
Wireless LANs protect their data through the Wired Equivalent Privacy (WEP) encryption standards that now make wireless communication at least as safe as any wired ones. This encryption is generally effective at preventing security breaches (eg. radio wave snoopers and data miners) that are always of concern in a school environment. Firmware updates to WEP are constantly under review, and concerned school administrators can implement additional security measures by connecting user students through the Virtual Private Network (VPN).
Interference
The wireless LAN access point must be centrally located where radio signals can reach it with minimal interference. Too many classroom walls can greatly reduce the wireless range. Also, careful non-overlapping channel selection is essential to avoid interference between nearby wireless access points in a large school.
Interference can be an issue with devices sharing the same radio waves or other nearby wireless networks. Dynamic Frequency Selection (DFS) senses existing broadcasting on the spectrum and automatically avoids it, while Transmit Power Control (TPC) adjusts the signal power depending on proximity of devices and essentially prevents them from shouting at each other. DPS and TPC are now mandatory for equipment in North America.
Wireless LAN networks give the classroom a feature common to many businesses in which the students’ wireless devices communicate with a central wired node on the LAN. This practical approach is in contrast to the peer-to-peer mode. The client-server structure, rather than equal peer-to-peer nodes that simultaneously function as both clients and servers to other nodes in the wireless network, is better suited to classroom applications. Centralized access to the Internet, local printers or other wired services through infrastructure mode wireless LAN connections to an access point is the most appropriate classroom set-up for signal strength, security, and network management. When the wireless client/student initiates the download/upload and the wired LAN server reacts to and satisfies these requests, and file transfers can be managed by the teacher and school administration.
Wireless routers for this set-up have dropped in price considerably over recent years and their reliability has improved greatly. Also, peer to peer systems do not permit quick and easy reconfigurations of multiple independent users, and security would be a nightmare if each device needed to be configured separately with any reconfiguration made to the classroom (e.g. if a new mode were added). Broadband routes for wireless service offer firewall capability built into the device and are configurable through its own software. Maintenance and upgrades are less expensive in the long run, and connection sharing software packages (ICS) are available with a nominal fee or free.
Wireless LANs protect their data through the Wired Equivalent Privacy (WEP) encryption standards that now make wireless communication at least as safe as any wired ones. This encryption is generally effective at preventing security breaches (eg. radio wave snoopers and data miners) that are always of concern in a school environment. Firmware updates to WEP are constantly under review, and concerned school administrators can implement additional security measures by connecting user students through the Virtual Private Network (VPN).
Interference
The wireless LAN access point must be centrally located where radio signals can reach it with minimal interference. Too many classroom walls can greatly reduce the wireless range. Also, careful non-overlapping channel selection is essential to avoid interference between nearby wireless access points in a large school.
Interference can be an issue with devices sharing the same radio waves or other nearby wireless networks. Dynamic Frequency Selection (DFS) senses existing broadcasting on the spectrum and automatically avoids it, while Transmit Power Control (TPC) adjusts the signal power depending on proximity of devices and essentially prevents them from shouting at each other. DPS and TPC are now mandatory for equipment in North America.
Performance
As more school wireless devices utilize the WLAN, performance degrades even further. Typically, the wireless network will support a limited number of hosts due to bandwidth limitations, but greater classroom mobility of wireless LANs can help offset these performance disadvantages and technology aimed at increasing bandwidth is being improved rapidly.
Video streaming can pose a problem when bit streams peak at 8Mbps, and can be too much for the wireless broadband. Furthermore, additional student users accessing the network will share the available bandwidth and reduce their personal allotment, which can potentially affect such actions as streaming media.
Cross compatibility of wireless nodes can also be an issue. Therefore, when considering school expansion, the interoperability between access points from different manufacturers must be considered.
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