User's Manual

U-NII Config & User Guide 5.2 Axxcelera Broadband Wireless
many sectors and few subscribers per sector. The fundamental limit in deploying in
this manner is Line of Sight (LOS) coverage.
While the above are generalizations, they can be used effectively as a starting point
for developing an RF plan for deployment. However, based upon the specifications
of the AB-Access equipment, it is necessary to have some pre-defined RF coloring
schemes. To better understand the benefits of different coloring schemes, a basic
concept of interference types should be understood.
13.10 Interference Types
There are four distinct types of interference that can occur in a cellular reuse pattern.
Each unique in its geometry and imposes unique frequency reuse constraints.
EFFECT INTERFERENCE TYPE
Would affect only the one SU. Could
affect other units if they are in the
same area.
Type 1 – Downlink
Downlink to Subscriber Unit Interfered with by another
Access Point transmission.
Would affect only the one SU. Could
affect other units if they are in the
same area.
Type 2 – Downlink
Downlink to Subscriber Unit Interfered with by a Subscriber
Unit Uplink in another cell.
Would affect all units in the sector.
This would be a constant source of
interference.
Type 3 – Uplink
Uplink to Access Point Interfered with by another Access
Point transmission.
Becomes critical if facets using same frequency face each
other.
Would affect all units in the sector.
Could be an intermittent problem
based on the amount of data that
interfering SU is transmitting.
Type 4 – Uplink
Uplink to Access Point Interfered with by a Subscriber Unit
uplink from another cell.
Hardest to eliminate and will reduce the performance of the
whole system.
March 10, 2003 Company Confidential Page 139 of 149