U.S. flag

An official website of the United States government, Department of Justice.

Operational Test Bed-Alexandria (OTB-A) Communications Interoperability Gateway Subsystems Operational Test Document

NCJ Number
Date Published
66 pages
This report details the results of tests conducted to verify proper operation of a communications interoperability Gateway Subsystem based on an ACU-1000 Intelligent Interconnect System.
This Subsystem has been installed at the Alexandria Police Department (Virginia) and interfaced with the department's existing communications infrastructure and other law enforcement and public safety agencies in the metropolitan Washington region. The resulting communications interoperability capability allows direct voice over-the-air radio communications among multiple law enforcement agencies that use radio systems which operate in different frequency bands, or operating within the same frequency band but using incompatible modulation formats or trunking techniques that defeat interoperability. Both functional and operational tests were conducted. The functional tests were designed to check the communication links by performing radio checks with participating agency dispatch units and deployed patrol units. Operational tests 1 and 2 were scripted tests that simulated operational scenarios that involved the participating agencies. Based on the data collected in those tests, several modifications were made to the Gateway Subsystem configuration. The exercises were then conducted again as operational tests 3 and 4. Overall, the Gateway Subsystem met the functional requirement of allowing officers from one agency using their own agency's radio system to directly communicate with officers of another agency by using a radio system that operated on a different frequency band. Initial results were acceptable and were improved by conducting several sessions of fine-tuning parameter settings of the ACU-1000. Recommended improvements encompass modifications to the ACU-1000 by the manufacturer, expansion of the number of agencies included in the Communications Interoperability Capability, and completion of the Gateway Subsystem installation to allow testing of functions not evaluated in the current tests. 2 figures, 11 tables, and appended functional test ACU-1000 log file

Date Published: January 1, 2001