Page 13 - GuideFWA

Part 1.

EXECUTIVE SUMMARY OF THE REPORT OF THE
PCC.III INTERFERENCE EXPERTS GROUP ON INCOMPATIBILITY ISSUES BETWEEN
FWA AND PCS SYSTEMS

This report discusses the analysis of the PCC.III Interference Experts Group regarding
interference between Fixed Wireless Access (FWA) in the 1910-1930 MHz band and Personal
Communications Services (PCS). For licensed PCS, which operates in the bands 1850-1910
MHz and 1930-1990 MHz, it is the potential for adjacent channel interference that is of concern.
The results of the Group’s analysis are presented in terms of the minimum separation distances
required between the transmitter of one wireless technology and the receiver of another to
prevent a given rise in the noise floor in an adjacent-channel receiver. For unlicensed PCS
(UPCS), which operates in the 1910-1930 MHz band, the concern is the potential for cochannel
interference between FWA and UPCS. Due to time constraints, the Group was unable to arrive
at closure on the FWA/UPCS issue, and the reader is referred to two contributions submitted to
the Group on this topic.1

In reviewing the results presented here, the reader must bear in mind that analysis of radio
interference between different systems is an inherently complex problem. However, time
constraints did not allow for a more detailed assessment. In fact, the time pressure was such that
changes to the numerical calculations and parameters were still being made on the day that this
report was released. Some specific areas of investigation which might warrant additional work
are identified in Section IV. The reader is encouraged to review that section to better understand
the context of the results and the summary table. The reader is also encouraged to consult the
detailed calculations and results for each case, which show the rise in noise floor vs. separation
distance for adjacent-channel interference.

1 PCC.III-918/97, “Analysis of Cochannel Interference from DECT FWA Systems to Isochronous UPCS” and
PCC.III-922/97,”Coexistence Between FWA and Isochronous UPCS Equipment on the Band 1910-1930 MHz”

Inter-American Telecommunication Commission 3