Orange County NC RaCEsm Results - Laserfiche WebLink

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CTA Communications Orange RaCE Test Report 7.0 Test Method 7.1 RaCE Test System Capabilities and Characteristics RaCE coverage tests were conducted both in the "talk-in" and "talk-out" directions using radios designed to operate in the system under test. The results from these tests are correlated in apost-processing step to allow presentation on a detailed map of the test area. Received signal strength (RSSI) information was also gathered for the control channels of other IWN radio sites as the mobile traversed the test area. All of the tests were conducted in the continuous by time mode. Each measurement was tagged with position and time information derived from a GPS receiver attached to the mobile unit. This allows for the accurate display of the test locations as well as the correct correlation of "talk-in" to "talk-out" results. 7.1.1 Talk-In and Talk-Out DAQ Testing In talk-in and talk-out DAQ testing, the mobile unit initiates the test by sending a test message and the stationary unit responds with the same test message. A minimum mobile speed of 5 mph was set to initiate the test in order to include the effects of multi- path fading. The mobile unit operates the PTT line and waits for a transmit power sensor "TX" condition lasting for at least 0.5 seconds. This can only occur if a channel grant has been obtained in trunking systems and assures the availability of a talk path through the system. The test message is then sent to the transmitter followed by a return to the receive condition. At the stationary unit, the test message is recorded and permanently stored together with a time stamp. The time stamp is used in post-processing to correlate the actions of the two units in order to display the transmit position of the mobile unit. The stationary unit then generates a new test message and sends it out to the mobile unit while keeping track of the time sent. The mobile unit receives and stores the message along with the position and time stamp. The message is then analyzed for DAQ. A color code is assigned to the tested position on the operator's map indicating the DAQ as seen by the mobile. The mobile then waits until the proper time has elapsed before repeating the process. 7.1.2 RSSI Test Mode The RSSI Test Mode is used for received signal strength recording during the DAO Test Mode or it may be used as a standalone test. The recording of RSSI will show the received signal level in dBm during the receive portion of the DAQ test using the same time and position. A minimum speed of 5 miles/hour is imposed on the start of each data gathering period to prevent long periods of data when the vehicle is stopped as well as to average out multi-path fading effects. - 21 - NS1yIM ,~~¢..~. ~~