Cambium Networks PTP 250, User Manual

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Regulatory planning Chapter 2: Planning considerations
2-4 phn-2510_002v000 (Mar 2012)
Certain regulations have allocated certain channels as unavailable for use:
x
Europe has allocated part of the 5.4 GHz band to weather radar.
x
The UK and some other European countries have allocated part of the 5.8 GHz band to
Road Transport and Traffic Telematics (RTTT) systems.
Where regulatory restrictions apply to certain channels, these channels are barred
automatically by the use of the correct country setting. For example, at 5.8 GHz in the UK
and some other European countries, the RTTT band 5795 MHz to 5815 MHz is barred.
With the appropriate configuration for a country in this region, the PTP 250 will not
operate on channels within this band.
The number and identity of channels barred by the country selection is dependent on the
channel width selected.
Radar detection
The PTP 250 fully conforms to regional regulatory requirements for radar avoidance.
In regions that mandate DFS, the unit first ensures that there is no radar activity on a
given channel for a period of 60 seconds before radiating on that channel. Once a channel
has been selected for operation, the unit will continually monitor for radar activity on the
operating channel. If detected, it will immediately cease radiating and attempt to find a
new channel.
Radar avoidance requirements in the 5.4 GHz band are defined as follows:
x
For the EU: in specification EN 301-893 version V1.5.1.
x
For the US: in the specification FCC part 15.407 plus the later requirements covered in
USA and Canada specific information on page IV .
x
For Canada: in the specification RSS210 Annex 9 (Issue 7).
Radar avoidance at 5.8 GHz is applicable to EU operation (not FCC/IC) and the
requirements are defined in EN 302 502.
Channel width
Select the required channel width for the link (20 MHz or 40 MHz). The wider channel has
the greater capacity. As narrower channel widths take up less spectrum and have a
greater link budget, selecting a narrow channel width may be a better choice when
operating in locations where the spectrum is very busy.