CoSN: The Consortium for School Networking

Executive Summary:
A Guide to Wireless LANs in K-12 Schools


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A Guide to Wireless LANs in K-12 Schools is the first report from CoSN's Emerging Technologies Committee. The 28-page report examines the implementation of wireless LAN technologies in K-12 schools and identifies challenges, options and lessons learned. The goal is to provide a practical road map for CTOs, CIOs, school administrators, technology coordinators and others charged with planning for wireless implementation. The report was updated in January 2005 to reflect new wireless standards. The report (which includes the January 2005 updated) is available for sale from CoSN's Catalog.

Why Wireless?

The report, developed with input from several wireless technology providers and many educators, explores the ways in which eight different districts are using wireless LAN technology. Here are some of the most compelling reasons schools give for purchasing wireless LANs.

Mobility: Wireless networking allows users of laptops, notebooks, PDAs, tablet PCs and wireless Voice Over IP (VoIP) telephone devices to roam freely on campus while remaining connected to the school's network.
Flexibility: With frequently-changing needs, schools are often faced with the need to move classrooms, add "portables," retrofit older buildings and reconfigure computer networks. With WLAN technology, it is possible to connect portables or older buildings that have hard-to-access walls and to change lab locations and classroom setups frequently and easily without the need for hard-wire drops.
Savings: Eliminating the need to wire and rewire can result in a tremendous financial savings for schools. Space savings are possible as well, with wireless mobile labs frequently taking the place of the older, space-consuming hard-wired labs.
Expandability: By adding on to existing networks - rather than replacing the wired with the wireless - districts expand their options without losing their initial investment in infrastructure.

Understanding the Standards

In order to provide decision-makers with an overview of their options, this report takes a look at the various versions of the 802.11 standard set by the Institute of Electrical and Electronics Engineers (IEEE). The three main choices for schools today are:

802.11b: The oldest standard, which has already been widely adopted in schools and public facilities, 802.11b is likely to be in the picture for quite some time. It's biggest drawbacks are speed - with rates considerably slower than wired networks - as well as some interference and reliability problems.
802.11a: Second to come along, 802.11a delivers faster performance and is less prone to interference because it uses a less widely-used radio band than 802.11b. However, it has a shorter range than the older wireless technology, is not as good at penetrating walls and - of greatest concern - is not backward-compatible with 802.11b. For these reasons 802.11a is most seriously being considered for point-to-point wireless access, connecting nearby buildings to one another.
802.11g: The newest standard, which is receiving lots of attention, is 802.11g. It is compatible with - and operates in the same radio band as - 802.11b but has speeds comparable to 802.11a. Most observers expect costs for 802.11g to fall as it gains widespread acceptance as the wireless solution for applications that require high bandwidth.

Security Issues

Security concerns top most technology planners' lists of potential drawbacks to wireless technology. Although a number of security measures were built into the 802.11 standard, it is almost universally accepted that wireless networks are considerably less secure than wired ones.

A number of vulnerabilities can allow hackers to gain access to a school's wireless network. While the goal of such "whacking" is most often to gain free Internet access, the same security holes can potentially be used to access confidential student information, alter records, or inflict malicious damage of other sorts on school LANs.

The IEEE's 802.11 task group is hard at work on specifications for a new security standard to be called 802.11i. In the meantime, the report outlines a variety of interrim options for schools including improved encryption schemes, requiring that access to sensitive data be limited to wired users, the implementation of firewalls, and the use of Virtual Private Networks.

At the same time, it is important to understand that increased security generally involves tradeoffs - in terms of cost, speed and resource time needed to make upgrades, change passwords and generally manage the security systems so that they work efficiently.

Steps in Designing a WLAN

Determining the Scope: A scope document is frequently used to define the performance specification for a site - including the desired applications of wireless and the number and type of devices to be used. Performance specifications go on to define what the wireless infrastructure must be able to do-for example, support up to 25 laptops simultaneously with a maximum of 50 laptops connecting to and using the Internet.
Planning the Layout: Once the scope of the implementation has been determined, it is necessary to design the layout of access points to maximize coverage and minimize cost. This generally involves a professional site survey to determine the number of access points needed, their placement and whether they will be fixed or mobile. Maximum coverage needed and total devices available must be balanced to create the most cost-effective layout. At the same time, you will want to have a plan in place for extra access points to be added as additional users and connections enter the picture.
Selecting Wireless Devices: Access points and wireless mobile devices vary in price and feature. The sorts of factors to consider in determining what your district will buy include: manageability (what sorts of control your network administrators will want to have over the system - and at what cost?); scalability (do the devices fit into a long-term strategy, with upgrade paths as needs change?); level of manufacturer support; dependability and performance, and; compatibility with existing devices.
Evaluating and Planning for Expansion: The planning process does not stop once you have purchased and installed your first wireless networks. Many districts are choosing to phase in their wireless installations gradually, piloting them in one school or department to analyze the feasibility of expansion. Careful monitoring of usage patterns, unexpected problems and costs, and user opinion is essential to determining next steps.

Total Cost of Ownership

As all technology planners know, ignoring the questions of Total Cost of Ownership (TCO) over the lifetime of a technology can lead to unforeseen expenses and complications. The report includes a chart and a description of a number of factors that must be taken into consideration as schools budget realistically for wireless technology. These include:

Installation and Hardware Costs: WLAN components include access points, computers or other devices equipped with wireless interface cards (NICs), and management software to oversee it all. Costs vary tremendously depending on a school's needs. Other implementation costs include consultant fees for people hired to do site surveys and offer purchasing advice. If, as is the case in a number of schools profiled in the report, wireless technology is leading to the increased use of laptop and mobile hardware, the cost of these devices need to be factored into the equation.
Maintenance, Support and Upgrading: As with most new technologies, deployment of wireless networking involves a considerable amount of work on the part of technology coordinators, network managers and support staff. New management tasks range from the security monitoring described above to managing upgrades as new options are rolled out to maintaining and scheduling the use of mobile labs. Cost estimates need to include such human resource issues.
Training and Professional Development: Although smooth implementations of wireless technology often mean that teachers need little in the way of technical training, schools must find ways to train and support technical staff, allowing them to stay up-to-speed on the technology choices, security protocols, and more. In addition, a number of schools report that they have added new components to their professional development program, focusing on the curriculum opportunities and management challenges that can result from going wireless.

Lessons Learned

While the educators interviewed for the report have concerns about costs, security, technical growing pains, and the amount of time needed to build and maintain a wireless network, they have many positive observations about WLAN technology. In general they report that teachers and students have adapted quickly to wireless options and greatly appreciate the added flexibility and mobility it offers them.