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Chapter 3: System planning
Radio spectrum planning
Page 3-22
Conforming to the limits
Ensure the link is configured to conform to local regulatory requirements by installing license
keys for the correct country. When using connectorized ODUs with external antennas, ensure
that the antenna gain and feeder loss is configured correctly in the ODU.
Available spectrum
The available spectrum for operation depends on the regulatory band. When configured with
the appropriate license key, the unit will only allow operation on those channels which are
permitted by the regulations.
Certain regulations have allocated certain channels as unavailable for use:
•
ETSI has allocated part of the 5.4 GHz band to weather radar.
•
UK and some other European countries have allocated part of the 5.8 GHz band to Road
Transport and Traffic Telematics (RTTT) systems.
The number and identity of channels barred by the license key and regulatory band is
dependent on the channel bandwidth and channel raster selected.
Barred channels are indicated by a “No Entry” symbol displayed on the Spectrum Expert and
Spectrum Management web pages (
Spectrum Expert page in radar avoidance
mode on page
Channel bandwidth
Select the required channel bandwidth for the link. The selection depends upon the regulatory
band selected.
The wider the channel bandwidth, the greater the capacity. As narrower channel bandwidths
take up less spectrum, selecting a narrow channel bandwidth may be a better choice when
operating in locations where the spectrum is very busy.
Both ends of the link must be configured to operate on the same channel bandwidth.
Note
PTP 670 supports only the 20 and 40 MHz channel bandwidth in the HCMP topology.
Frequency selection
PTP topology in regions without mandatory radar detection
In regions that do not mandate DFS, choose DSO or Fixed Frequency: