DIAGNOSTX - Radio Signal Metrics

This is the first and only tool that allows over-the-air evaluation of radio signals, allowing service personnel to proactively service suspect radios before there is a failure in the field.

Any radio system operator now has an easy way to assure compliance with the mandated FCC Emission Mask guidelines. Eliminate failing radios in the field and costly NTFs on the bench. Only the radios that are failing need to come into the shop – don’t waste time on “good radios.”

DiagnostX metrics for P25 systems:

RF Frequency Error — This metric sets the limit that the frequency offset cannot exceed for the transmission to be considered good. 500Hz is the recommended value for this field. 1209Hz is the maximum allowed value.

Symbol Frequency Error 600 — This metric sets the limit that the Symbol Frequency Error (600) cannot exceed for the transmission to be considered good.

Symbol Frequency Error 1800 — This metric sets the limit that the Symbol Frequency Error (1800) cannot exceed for the transmission to be considered good.

Modulation Fidelity — This metric sets the minimum that the Modulation Fidelity (% of 1800) can be for the transmission to be considered good.

Maximum Frequency Deviation — This is a measure of how far the maximum modulated frequency component is from the center of the licensed channel (in Hz).  For example, if the frequency deviation is 3000 Hz and the frequency error is 1000 Hz, then the maximum frequency deviation would be around 4000 Hz.  The result may also be inflated if there is a notable amount of variation in the frequency error throughout the message.

Probable Emission Mask Non-Compliance — The frequency error, frequency deviation, and maximum frequency deviation are used to determine radios that are probably exceeding the FCC Emission Mask.

DiagnostX metrics for legacy systems:

Frequency Error — This metric provides the difference between the licensed channel center frequency and the center frequency of the received signal (in Hz).  For example, if the licensed channel is centered at 810.025 MHz and the received signal is centered at 810.026 MHz, then there is a frequency error of 0.001 MHz or 1 kHz.  This value may be positive or negative and it is averaged over the entire received signal.

Frequency Deviation This reports the difference between the center frequency of the received signal and the modulated frequency.

Frequency (Error) Variation It provides an indication of how stable the frequency is throughout the entire message.

 

Modulation Fidelity — This metric sets the minimum that the Modulation Fidelity (% of 3125) can be for the transmission to be considered good.

Probable Emission Mask Non-Compliance — The frequency error, frequency deviation, and maximum frequency deviation are used to determine radios that are probably exceeding the FCC Emission Mask.