Product Info

Infinet Wireless: Technical Documentation – InfiMAN Evolution
11 https://wiki.infinetwireless.com/display/DR/InfiLINK+XG+and+InfiLINK+XG+1000
Planning considerations – 41
4.4 Spectral aggregation
It is recommended to placebase stationsectors above the subscriber terminals as high as possible to provide
proper antenna tilt in vertical direction and to minimize self-interference. The optimal antenna tilt is defined by the
vertical beam width of the sectoral antenna and by the required sector coverage. It must cover all the area, where
you plan to deploy the subscriber terminals.
Spectral aggregation should be taken into account when planning composite backhauling links, when installing
devices in close proximity to each other on the same pole or in order to implement redundancy and link
aggregation.For more information, proceed with the "
Link aggregation, balancing and redundancy
11
" article. The
devices located close to each other can cause mutual interference. Do not ignore the spectral aggregation rules,
otherwise it can lead to a degradation of the wireless links.
The document will provide recommendations on distance and frequency separation for scenarios with and without
an external synchronization hub. An external clock source allows you to synchronize the time (the beginning of each
second) on multiple devices, up to 7 devices, with an accuracy of less than a microsecond so that all connected
devices can turn on the transmitters at the same time. This completely eliminates the mutual influence of
neighboring sectors, when one transmitting device with its powerful signal prevents the neighboring device from
receiving weak signals from its terminals. Wireless devices synchronization using AUX-ODU-SYNC makes it possible
to reuse the frequency within the same base station, that is, different sectors of the same base station can operate
on the same frequency channels. When using synchronization, a four-sector base station can operate on only two
frequency channels, significantly increasing the real spectral efficiency of the system.
Mutual interference occurs not only between sectors and subscriber terminals of one multi-sector base station, but
also between different base stations when they are densely located in a limited frequency range. Synchronization of
base stations prevents mutual interference of such base stations and subscriber terminals that working with them.
Recommendations for istance and frequency separationfor a four-sector ABAB base station are given below.