Rf Interference Sources; Line Of Sight (Radio Path Planning) - Aruba AP-85 Installation Manual

RF Interference Sources

Other 802.11a/b/g or broadband access equipment operating nearby

Industrial RF welding equipment or other Industrial, Scientific and Medical (ISM) equipment that

utilizes RF to heat or alter the physical properties of materials
Military, Commercial Aviation or Weather Radar Systems


Line of Sight (Radio Path Planning)

AP-85 Series access points are capable of performing as one of the following:
Point-to-point wireless distribution system (WDS) bridge

Point-to-multi-point WDS bridge

Enterprise mesh point (MP)

Enterprise mesh portal (MPP)

N O T E
A wireless bridge or mesh link requires a "radio line of sight" between the two antennas for optimum
performance. The concept of radio line of sight involves the area along a link through which the bulk of
the radio signal power travels. This area is known as the first Fresnel Zone of the radio link. For a radio
link, no object (including the ground) must intrude within 60% of the first Fresnel Zone.
Figure 8
Figure 8 Line of Sight
If there are obstacles in the radio path, there may still be a radio link but the quality and strength of the
signal will be affected. Calculating the maximum clearance from objects on a path is important as it
directly affects the decision on antenna placement and height. It is especially critical for long-distance
links, where the radio signal could easily be lost.
When planning the radio path for a wireless bridge or mesh link, consider these factors:
Avoid any partial line of sight between the antennas.

Be cautious of trees or other foliage that may be near the path, or may grow and obstruct the path.

Be sure there is enough clearance from buildings and that no building construction may eventually

block the path.
16 | Outdoor Planning and Deployment Considerations
To configure the AP-85 as a mesh point or mesh portal, you must install a mesh software license on
a Mobility Controller as a software license key. Contact your sales account manager or authorized
reseller to obtain the software license. There are several mesh software licenses available that
support different maximum number of APs. The licenses are cumulative; each additional license
installed increases the number of APs (mesh nodes) supported by the Mobility Controller.
illustrates the concept of a good radio line of sight.
Visual Line of Sight
Radio Line of Sight
Aruba AP-85 Outdoor Access Point Series | Installation Guide