B-19
Appendix B AN100U/UX Event Log Messages
Redline Communications Inc. Confidential and Proprietary
Interference Messages at Startup
At startup, the AN100U/UX (Version 1.2 and higher) performs an RF channel listening
sequence for the purpose of detecting interference on the uplink channel. During this
sequence, the RF is in continuous Rx mode while the PHY is programmed to receive and
interpret a long preamble.
If no preamble is detected by PHY during a one-second period, then no event message
will be displayed in the event log regarding this action and the sector controller will start
and continue with normal operation.
If any preamble is received, the sector controller will continue to listen to the channel for
another 3 seconds trying to decode a DL-Map. If any 802.16d DL-Map is decoded
correctly, the following message will be displayed in the event log:
WARNING: Uplink Channel Conflict with [BS Id] ([x] dBm)
This message indicates the BS Id of another sector controller that has the following
RF-PHY configuration that is the same as the uplink channel frequency of this sector
controller
•
same DL channel frequency
•
same Cyclic Prefix
•
same Channel Bandwidth
If a preamble was received but no DL-Map was decoded, the following message is
displayed:
WARNING: Unknown Interference was Detected on the Uplink Channel ([x] dBm)
When interference is detected one of the above messages is displayed in the event log,
however the sector controller will not change the state of the air Interface. The sector
controller will continue with normal operation.
Interference on the uplink can be difficult to detect, so please note the following:
•
Interference may be present on the uplink channel without being detected at startup.
In this case no message is displayed.
•
The sector controller may detect a preamble even though the interference is not
caused by another 802.16d system. You may see the second message, in this case.
•
Even if the RF and PHY parameters are the same (frequency, channel bandwidth,
cyclic prefix), this sector controller may not be able to receive a DL-Map and the
second message will be displayed in this case.
Detecting Interference with Local or GPS Synchronization
The channel listening sequence is slightly more complicated when local or GPS
synchronization is used. In this case the sector controller synchronizes its signal first with
the Master or Master with GPS. After synchronization (frame aligning) is achieved, the
sector controller tries to detect the interference only in the uplink interval of the frame.
