Wireless data communication alternatives for small public safety agencies: how one community cost-effectively solved its expanding field data requirements

Abstract

A growing number of Public Safety agencies have begun leveraging wireless data communication technology to improve tactical response capabilities as well as overall productivity. For years police departments subscribed to CDPD (Cellular Digital Packet Data) services to provide officers with basic dispatch data and criminal database access. Now as cellular carriers have deactivated CDPD and shifted to 2.5G and 3G data services such as 1xRTT, GPRS and EDGE, police departments are scrambling to fill the void. Not surprisingly, the extraordinary investments cellular carriers made to upgrade their infrastructures have been transferred to the customer, with monthly fees running as high as $80 a month per user. It's no wonder public safety agencies have been reluctant to adopt these services. Lost in the fray are those smaller police departments which account for nearly 90% of the nation's total. This group has increasingly sought out alternative data communication solutions that are not predicated on budget-busting monthly access fees. One such example is the Marco Island Police Department (MIPD) in Southwestern Florida that received a Federal grant to augment its existing voice communications with data. After evaluating several different technologies and vendors, MIPD chose a 900 MHz ad hoc mesh network solution based on its ability to provide reliable, high-speed and secure IP-based data communications over extensive distances. This paper will discuss technical details of Marco Island's mobile mesh network implementation; including: coverage area with 900 MHz spread spectrum radios, strategic repeater tower placement, interference, throughput performance, and the necessity for application-persistence software.