Building upon Eric's comments, I would highly recommend using DSO for the frequency setup (versus fixed frequency), even if you are going to use a fixed frequency setup. DSO should select the 'best' channel available on startup and you can configure the radio to 'bar' specific channels from being selected by DSO. Essentially you can bar all of the undesired channels, fixing the frequency at a certain channel. This allows flexibility in the future, if you need to change channels (un-bar new frequency desired and bar current frequency). More information on DSO here.
In your particular environment, you will benefit from Asynchronous DSO (different Tx channels on each end of the link). Eric mentions this in a fixed frequency environment, but it is also possible using DSO. Under the spectrum expert page of the master, you can enable A-DSO, but I would also recommend changing the hopping parameters to the following:
Hopping Margin: 5dB or greater (typically 6-8dB). This will prevent the radio from changing channels due to small environment variance
Hopping Period: 600 (10 min) or greater. This will prevent the radio from changing channels too often due to isolated interference bursts. Basically that the interference is permanent.
Interference Threshold: Environment specific. If the measured interference on a channel exceeds the specified threshold, then DSO will instruct the wireless to immediately move to a better channel. If a better channel cannot be found the PTP 670 Series will continue to use the current active channel. (Default –85 dBm). In your environment, a value of -75dBm should be sufficient.
If setup properly and optimal radio operation, the PTP670 should stay on the current local channel (5742) and move to 5792 or 5802 on the remote channel.
It may also be worthwhile to setup this link within LINKPlanner and specify the corresponding noise floor/interference values for each end of the link. You can also verify predicted RSL on both ends to ensure optimal alignment. As will all unlicensed links, interference will signficantly impact performance. Moving to a smaller channel may also push more more throughput through the link, and this scenario can be predicted using LINKPlanner (with interference values entered).
- White Paper DSO Final.pdf (741 KB)