Radio Frequency (RF) Issues

Use system diagnostics and the site survey screen to interpret RSSI, FER and Link Quality.

As a general rule:

  • Recieved Signal Strength Indicator (RSSI) => 30.
  • Frame Error Rate (FER) should be as close to 0 as possible
  • Link Quality should be => 3.

High frame error rate (FER)

You may have a situation where RSSI is high, but FER is also high, giving a low overall Link Quality. Potential causes of this kind of interference are:

  • There is another RF device in the area. This can be tested using a band monitor or spectrum analyser.
  • There are reflective surfaces in the area causing Long Delay Spread Multipath interference. This kind of interference is improved by careful transceiver placing, to avoid signal reflection. You may need advice from your Clear-Com representative in this situation.

National radio carrier frequencies

The carrier frequencies allocated for a radio space vary according to location. This affects the amount of beltpacks that can be supported in one RF cell.

Location Number of carrier frequencies Maximum beltpacks in one RF space
United States 5 25 beltpacks
European Union and elsewhere 10 50 beltpacks

See also:

Interpreting the Site Survey Screen