iDirect Terms

Symbol offset (as observed from iMonitor or via telnet) = how many symbols the hub has adjusted a specific remote(s) timing...(since the remote was acquired into the network).  

The hub makes sure that bursts arriving from remotes stay centered in their time slot...adjustments are made every 20 seconds through the UCP (Uplink Control Parameters/Process) to keep the bursts centered.  

Frequency Offset = tx frequency "drift" as received by the Hub line card. It is measured by the network, adjusted, and reported back to the remote (via UCP message) to be implemented (actually adjusted on the remotes tx parameters).   The next time the remote transmits a burst, it uses the specified frequency offset (which was dictated by the network/hub).