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RSSI (Received Signal Strength Indication) and Interference

  1. Mar 19, 2010 #1
    Hi,

    I Want to know: High GSM RSSI mean Interference? the reason behind High RSSI ist only Interference?

    Thanks
     
  2. jcsd
  3. Mar 19, 2010 #2

    berkeman

    User Avatar

    Staff: Mentor

    Interference or another signal. Where are you seeing this? Here's more info on RSSI:

    http://en.wikipedia.org/wiki/Rssi

    .
     
  4. Mar 20, 2010 #3
    Well, in GSM you have a 200KHz channel in one of the GSM bands, assigned to a user/mobile.
    So if you are measuring at the mobile, then whatever enters the 200KHz channel contributes to RSSI - interference, jammer signals, the actual signal that you are supposed to receive, etc.
    When you measure RSSI at the Base Station, then you are measuring the whole band-range
    that a TRX (Transceiver) board in the BTS handles. This band-range can be Nx200KHz, N being the number of ARFCNs (Absolute RF Channel numbers) the TRX handles. Here again whatever enters the band of the TRX contributes to the RSSI. But a TRX also measures the RSSI in the individual 200KHz band as well (to power-control the mobile correctly).

    Long story short -high GSM RSSI does not necessarily mean high interference. If you have
    a misbehaving phone that is screaming at the BTS tower, you will still measure high RSSI. If you are a phone too close to the tower, you measure high RSSI!
     
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