WIRELESS NETWORKING POLICY

Wireless network technologies are poised to play an important role at Broward County Public Schools.  Staff and students are quickly beginning to recognize the benefits of this mobile, untethered network. For this reason, installations have been appearing rapidly around the District. Unfortunately, many implementations are being done informally, with little or no planning. Broward Schools Education Technology Services Department believes that a coordinated, centralized delivery of wireless networking services is the best strategy to succeed in the face of these challenges. Our goal is to provide a common user experience across the District, efficiently support users, protect network resources, and provide a quality service. There are two major challenges:

1. Security and access control: Unless steps are taken to protect them, wireless LAN (WLAN) installations are open to anyone within range of the access point. If a wireless access point is connected to the Broward Schools network without restrictions, anyone with the proper equipment will be able to access the Broward Schools network, even from outside the building. Furthermore, anyone with the proper equipment could intercept traffic. They can see users' passwords as well as other data. As Broward Schools moves more and more services online, the amount of damage that can be done by unauthorized people is increasing.
2. Interference: There is a finite amount of bandwidth available for wireless use. The most common wireless LAN technology (802.11b) defines 14 possible frequencies. However they are close enough together that they can interfere with each other. Thus it is common practice to use only 3 (or possibly 4) channels. If wireless LANs are installed without coordination with others in the area, interference is likely. This may result in significantly degraded performance for everyone. One area of conflict of particular concern is the use of Bluetooth personal area wireless networking in areas that have Broward Schools WLAN coverage.  Because these two wireless networks both use the same general radio spectrum, there is the potential that either of the two systems will fail when the two are operating in the same area.  The likelihood of network connection failure increases as the number of competing Bluetooth and Wireless Local Area Networking (WLAN) are deployed near each other.  This factor should be considered in purchasing and deployment decisions as they relate to co-located WLAN and Bluetooth installations and use.

These dangers are not just theoretical: Tools to tap nearby wireless networks are widely available, even for palmtop devices.  Interference among competing wireless technolgies is already visible in several Broward Schools' buildings. 

Background

With the ratification of the 802.11b standard for wireless networking in 1999 and the subsequent proliferation of interoperable, affordable products that support that standard, wireless network technology has established itself as an important complement to the traditional wired data networks.

Mobile access to information improves our ability to communicate. Faculty, staff and students will have the ability to check email or their schedules from most places around campus. Access to the Internet will no longer be tied to a computer in an office, lab or classroom. Wireless network technology is also beneficial for gaining network access in locations that are difficult, expensive, or inconvenient to wire. Examples include large lecture halls, outdoor areas, conference rooms, etc.

Wireless networks have their limitations. For example, they are slower than wired networks. Wireless networks are also inherently insecure. Tools are readily available to capture someone else's communications, including passwords and other sensitive data. Wireless network users must take extra precautions and adhere to standards to ensure secure communications over a wireless network.

While the standard does allow a wireless network card from one vendor to connect to an access point from another vendor, the devices must all be carefully configured for this support. Every product also has proprietary features that don't interoperate. This is especially true when it comes to security and management. Consequently, wireless network standards and central management of the campus "air space" are necessary to protect valuable information resources and to ensure the highest degree of interoperability as one moves from one location to another on campus with a mobile device.

Suitability

Wireless systems offer a different type of service from wired service with respect to reliability, available bandwidth, security, and portability. Wireless service is an extension of the wired network for general-purpose network. It enables applications that require the mobility offered by wireless, but which don’t require the bandwidth or reliability of wired connections.

Wireless bandwidth availability is more limited than wired bandwidth and is shared among users in an area. As the number of users in an area increase, the available bandwidth to each user decreases. So wireless is less appropriate in areas of high user density, especially if high bandwidth applications are a requirement.  Given the limited bandwidth available per user, wireless currently works best for the relatively low bandwidth applications, such as web browsing and e-mail.

Wireless networks are NOT a replacement for wired networks. The purpose of the wireless network is to extend the wired network by providing Web browsing and e-mail access in areas of transient use such as common areas. Wireless networks have a much smaller bandwidth than wired networks; therefore, applications that require a large bandwidth may overload the wireless network. Wireless networks work best when the number of users is limited - the more users, the smaller the share of the bandwidth available to each.

Rationale for Standard / Policy

The purpose of this policy is to provide a highly reliable and reasonably performing wireless network service while ensuring network security and integrity and minimizing the interference between the campus wireless network and other wireless technologies deployed throughout the campus.