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Bit Error Rate Testing

With the introduction of RadioManager 5.8, RadioManager can be used to test bit-error and packet error performance of a radio link.

Bit-Error-Rate (BER) is not directly measured because RadioManager uses packets to test the link, but BER can be derived from packet-error-rate.

Raveon calls these types of tests “BERT” for Bit Error Rate Test.

To activate the BERT feature:

  1. Connect RadioManger to the radio you wish to test
  2. From the View -> BERT menu select BERT.
  3. Select the data pattern to send.
  4. Set the Interval to the number of milliseconds between packet transmissions.
  5. Click the START button, and RadioManager will begin sending the test packets to the device connected to the communication channel.

The BERT screen is show below.

BERT Screen

BERT Screen

You may select from a number of stock messages, for create your own by typing text into the second window from the top. Normally, RadioManager will put a packet sequence number at the beginning of every packet it sends, but this may be suppressed by unchecking the Add Sequence Number check box.

When running, RadioManager will automatically send a packet at the interval specified in the “Interval” box.

On the bottom of the BERT window are the communication statistics.  BERT counts how many packets it sends, and how many it receives.  It it sends more than it receives, it calculates the loss percentage and displays that.

To do a simple end-to-end link test, connect RadioManager to one radio, and on the other far-end radio modem, plug in a “loop-back dongle”.  For radio modem systems with DB9 serial ports, the loop-back dongle should connect pins 2 and 3 of the DB9 causing every byte that comes in the mode, to pass back to the transmit buffer and be re-send back over the air.

Below is a picture of a DB9 connection plugged into a Raveon M7 data radio modem.  Pins 2 and 3 are shorted together to do the BERT test.

Loop Back Connection

Loop Back Connection

 

Configure the two radios in the BERT test to communicate with each other:

  1. Same frequency
  2. Same IDs or set the ATMK netmask to 0000 to ignore the IDs
  3. Over-the-air data rate on both modems must be the same.
  4. Over-the-air protocol on both modems must be the same.

 

 

 

Filed under: Installation Information | Posted on February 21st, 2014 by John Sonnenberg

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