Wireless Networks In Motion?

Barkmullz asks: "Working closesly with a public safety department in my town, we have been thinking of implementing a mobile wireless network. This would, theoretically, allow public safety officers to send and received data (such as CAD) while in a moving or stationary vehicle. One of the requirements is to be able to move across multiple wireless networks. There are several vendors that offer such technology, like the Cisco 3200 Mobile Access Router. Even though we have a fairly good idea of what needs to be done, we are experiencing difficulty in finding good examples of other implementations of this kind. Sure, there is Seal Beach, Buffalo Grove, Lufthansa and others, but they are more sales-pitches than in-depth white papers. Security is, naturally, of great concern to us. However, due to funding constraints we are planning to use the publicly available 802.11x for the most part, use EAP or Cisco's LEAP and a RADIUS server for authentication, along with TKIP for encryption (aka WPA). Has anyone dealt with a wireless network of this type? If so what were some of your challenges and what are your recommendations for implementation?"