User's Guide Part 1

Table Of Contents

Chapter 1: Product description Wireless operation

• Second mode: the frequency of operation can be determined independently for each

direction. This mode is not permitted in radar regions.

Further reading

For information about…

Refer to…

Using DSO in PTP networks Using Dynamic Spectrum Optimization on page 1-16

Planning to use DSO Frequency selection on page 3-23

How to configure DSO Wireless Configuration page on page 6-21

Asymmetric DSO in non-radar regions Spectrum Management Settings on page 7-31

Radar avoidance

In regions where protection of radars is part of the local regulations, the PTP 700 must detect

interference from radar-like systems and avoid co-channel operation with these systems.

To meet this requirement, the PTP 700 implements the following features:

• The radar detection algorithm will always scan a usable channel for 60 seconds for radar

interference before making the channel an available channel.

• This compulsory channel scan will mean that there is at least 60 seconds service outage

every time radar is detected and that the installation time is extended by at least 60

seconds even if no radar is found.

• When operating on a channel, the spectrum management algorithm implements a radar

detection function which looks for impulsive interference on the operating channel. If

impulsive interference is detected, spectrum management will mark the current operating

channel as having detected radar (unavailable channel) and initiate a channel hop to an

available channel. The previous operating channel will remain in the unavailable state for

thirty minutes after the impulsive interference pulse was detected.

• After the thirty minutes have expired the channel will be returned to the usable channel

pool.

There is a secondary requirement for bands requiring radar avoidance. Regulators have

mandated that products provide a uniform loading of the spectrum across all devices. In

general, this prevents operation with fixed frequency allocations. However:

• ETSI regulations do allow frequency planning of networks (as that has the same effect of

spreading the load across the spectrum).

• The FCC does allow channels to be barred if there is actually interference on them.

Fixed frequency allocation is not recommended in radar avoidance regions, as any radar

detection would cause a system outage of at least 30 minutes.