User's Guide Part 1

Table Of Contents

Chapter 1: Product description Wireless operation

Spectrum management

The spectrum management feature of the PTP 700 Series monitors the available wireless

spectrum and directs both ends of the wireless link to operate on a channel with a minimum

level of co-channel and adjacent channel interference.

Spectrum management measurements

The PTP 700 Series performs two mean signal measurements per TDD cycle, per channel. This

mean measurement represents the mean received signal power for the 40 microsecond

measurement period.

The Spectrum Management algorithm collects measurements equally from all channels in the

operating band. This process is called the Channel Availability Check (CAC). The CAC uses a

round-robin channel selection process to collect an equal amount of measurements from each

channel. The CAC measurement process is not altered by the channel barring process.

Measurements are still collected for all channels irrespective of the number of barred channels.

Measurement analysis

Spectrum Management uses statistical analysis to process the received peak and mean

measurement. The statistical analysis is based on a fixed, one minute, measurement

quantization period. Spectrum Management collects data for the specified quantization period

and only at the end of the period is the statistical analysis performed.

Statistical summary

The display of statistical measurement on the Spectrum Expert page always shows a statistical

summary of all channel measurement. The mean and percentile values displayed for each

channel are calculated over a 20 minute statistics window period. All channel decisions are

made using the values computed over the statistics window period.

Spectrum management in fixed frequency mode

The transmit and receive frequencies can be fixed in a PTP 700 wireless link. Once fixed

frequency mode is configured, the spectrum management software will not attempt to move

the wireless link to a channel with lower co-channel and adjacent-channel interference.

Therefore this mode of operation is only recommended for deployments where the installer

has a good understanding of the prevailing interference environment. Care must also be taken

to ensure that the frequency allocations at each end of the link are compatible.

Fixed frequency mode is not available in regions where radar detection is required by the

regulations.