Wireless Networking

Wireless Networking Strategy

Overview

Issues for Yale

A Strategy

Overview

While Wireless LAN technology has been available for approximately four years, it has become increasingly popular in the last eighteen months as hardware prices have begun to drop to commodity levels. Wireless NICs are approaching $100, and enterprise-grade access points can be purchased for approximately $1,000. The current standard, known as 802.11b provides 11 megabit/sec bandwidth over a coverage area of roughly 200 ft. depending upon building structure. This is roughly equivalent to10 megabit/second wired hubs (under optimum conditions) and is adequate for light usage such as email and browsing. A new standard, 802.11a, providing 52 megabit/sec bandwidth is expected to be available soon albeit at higher cost and with a smaller coverage area. 802.11a access points and client cards are incompatible with 802.11b devices. A third standard, 802.11g, has recently been approved that provides 22 megabit/sec bandwidth and is backward compatible with 802.11b. Wireless LAN technology is basically a short-range service and is incompatible with long-range cellular data services which operate at substantially lower speeds. In all three standards the bandwidth is shared among connected machines, providing significantly lower performance than switched wire connections, which dedicate 10mb or 100mb to each machine.

Issues For Yale

ITS envisions potentially significant demand for wireless network service at Yale, due to the convenience of mobility for campus laptop/PDA users and the trend toward providing wireless transceivers as standard equipment in such devices.

ITS believes that the primary goal at this point should be to lay the foundation for a reliable wireless infrastructure that meets current needs while maintaining enough flexibility to incorporate improvements in the technology, and provide seamless growth to campus-wide coverage. In anticipation of improvements, investment in the technology should attempt to meet, but not encourage, demand.

What constitutes a reliable wireless infrastructure?

• Well-engineered installation of the access points including proper channel assignment and avoidance of airspace conflicts.

• Uniform support, maintenance, and documentation of wireless service across the campus.

• Security. Common policy for access to the wireless network, encryption employed to the extent possible and desired, clear understanding for users of the risks involved.

• Tracking improvements to the technology (better security, higher bandwidths, etc.) and devising strategy for incorporation into the Yale infrastructure.

• Standardization of access point hardware and designation of compatible client cards. This is rapidly converging to full interoperability, but problems may remain with older cards, driver versions, etc.

Uncoordinated implementation of wireless LANs presents several possible threats to a reliable infrastructure:

• Overlap in radio coverage of access points installed by departments in close proximity may cause significant impairments to performance. These would be unpredictable; a wireless LAN that has been working for months might suddenly and inexplicably bog down when the lab upstairs installs a new access point.

• While it is certainly possible to work these problems out, resolutions would require cooperation and technical analysis that is beyond the capabilities of some departments.

• Random use of security measures may inadvertently provide access to unauthorized individuals. In some locations, this could be by non-Yale users physically outside of buildings. All traffic between an access point and its users shares the same wavelength, so traffic that is not encrypted may be easily "sniffed".

• Uncoordinated configuration of access points and/or incompatibilities between different manufacturers access points and client cards could result in the inability of  wireless users to obtain seamless connectivity and adequate performance across the campus.

A Strategy

What steps can Yale take to ensure a reliable, robust wireless infrastructure? Some Universities have forbidden the connection of wireless systems by departments or, to varying degrees, deemed the wireless "airspace" to be under central authority. While this approach may work elsewhere, restrictive or punitive solutions typically do not work at Yale and can become an issue unto themselves. A far better approach for us would be to provide positive incentives to utilize the central University infrastructure. The incentives are reliable function, cost avoidance and convenience.

With these points in mind, ITS proposes the following strategy for Campus Wireless LAN Service at Yale. As the technology is evolving rapidly, this strategy should be reviewed periodically until wireless technology matures:

• ITS will begin to phase in wireless access in public spaces throughout the University within the current budget. Initial deployment would be in public conference rooms (those that may be used by any University department at no charge).  In order to avoid over investment in current technology, ITS proposes to provide service primarily to areas with significant existing demand, i.e. high presence of laptops and PDAs.

• While all machines using the network must pay the standard access charges, there will not be an additional charge for wireless service for those machines already paying for access to the wired network.

• ITS will configure, install, monitor, and maintain wireless service for departments, labs, etc. for the acquisition/installation cost of the access point. As demand grows, ITS will re-design the buildings wireless infrastructure, ensuring coverage for all interested parties. In order to make this an attractive alternative to do-it-yourself installations, ITS will consider using low-cost devices where they would meet the requirement, in accordance with DNO established hardware standardization preferences, and also offer to create building or area-wide proposals and broker the cost among the occupants.

• ITS will not attempt to prohibit departments or groups from providing their own wireless services providing they follow ITS technical standards that will ensure proper performance and reduce the risk of interference with other wireless installations or impairments to the Campus Network Backbone. Under the University Acceptable Use Policy, ITS is empowered to disconnect wireless installations that impair the Campus Network Backbone, ITS-provided wireless service, or other departmental wireless services. Local providers will need to agree that if subsequent demand justified service throughout the building, they would decommission their wireless service in exchange for access to the ITS-provided service.