Wireless Consulting Expertise

An independent school system in the San Francisco Bay Area needed a reliable and secure data network to link their two sites. The school includes kindergarten through eighth grade and occupies two campuses housing its elementary school and middle school. The two sites are located in the San Francisco Bay Area foothills about 1.5 miles apart, making line-of sight possible.

The school relies heavily on having a data link between the two campuses. In addition to data traffic between the sites, the school uses a Voice-over-IP (VoIP) capability for the phone system used by the administration offices and classrooms. The school originally looked into getting a dedicated link such as a T1 or Frame Relay line, but the recurring costs combined with the cost of equipment were far beyond the budget of a small private school. Instead, they decided to go wireless.

The school originally used an 802.11b (WiFi) solution to link the campuses. This was sufficient for the first year, but as usage by administration and students in the remote site increased, the WiFi solution proved inadequate. Users at the remote site frequently complained about slow network performance and dropped or fuzzy phone calls. A quick assessment of the wireless link by a Progent consultant revealed that the 802.11b link was working according to its specification. It consistently delivered 4Mb/s throughput, but once traffic saturated the WiFi bandwidth frequent retransmissions would ruin the line quality. Progent's consultant also observed that some neighbors were causing interference with the school's access point, which was publicly available.

Progent provided a solution that enabled the school to increase productivity and avoid the recurring costs of a dedicated link. Progent proposed Tsunami 60Mbps wireless bridge devices from Proxim. These plow-cost bridges are designed for connecting remote sites up to 2.5 miles apart and can reach even greater distances. This solution offered better performance and reliability than the alternative of amplifying the 802.11b network, and since it uses the 5.8Ghz band it was immune to outside interference.

The installation and configuration of the Proxim system was transparent to the users. There was no downtime during business hours and the entire link was installed in about one business day. After the link was established and the remote site moved to the Proxim solution, users noticed immediate improvements. Network performance was 8-10 times faster and line quality problems for the phone system disappeared. The network latency is less than 40 milliseconds over the Proxim link as compared to over 240 milliseconds for the 802.11b link.

Progent's solution also allowed the school to have a hot-swap redundant back-up wireless link between sites. If any problems are ever observed on the new link, it is a simple three-step procedure to switch back to the old system. The school also has the ability to separate network functions over the two links if the need arises in the future. In addition, Progent provided a limited 1–year warranty on the installation.

Proxim Tsunami products are highly secure. They are password protected, encrypted, and are not publicly accessible. Because they allow communication only between the Master and Slave Access Points, no snooping is possible.

Progent offers wireless consulting specialists who can help you plan, implement and maintain point-to-point and point-to-multipoint solutions running in the 2.4Gz band (both 802.11b and 802.11g) and the 5.8Ghz business band.

To contact Progent about consulting help for wireless integration, phone 1-800-993-9400 or send email to wireless-help@progent.com.