User`s guide

Planning and Installing Wireless LANS
User’s Guide
5-14
BreezeNET PRO.11 Series
5.2.2.2 Antenna Polarization
Antenna polarization must be the same at either end of the link. In most
applications, the preferred orientation is vertical polarization. Above-ground
propagation of the signal is better when it is polarized vertically. To verify antenna
polarization, refer to the assembly instructions supplied with the antenna set.
5.2.3 Construction Materials
A cell’s coverage area is affected by the construction materials of the walls,
partitions, ceilings, floors and the furnishings of the cell. Due to their intrinsic
nature, these materials may cause radio signal loss:
• Metal objects reflect radio signals. They do not let the signals pass through.
• Wood, glass, plastic and brick reflect part of the radio signals and allow part of
the radio signals to pass through.
• Water and objects with high moisture content absorb a large part of the radio
signals.
Use the following table as a guideline to predict the effects of different materials.
Table 5-1. Signal Loss Chart
Obstruction Additional Loss (dB) Effective Range Approx. Range
Open Space 0dB 100% 1000ft. (300m)
Window (non-metallic tint) 3dB 70% 700ft. (215m)
Window (metallic tint) 5-8dB 50% 500ft. (150m)
Light Wall (dry wall) 5-8dB 50% 500ft. (150m)
Medium Wall (wood) 10dB 30% 300ft. (100m)
Heavy Wall (solid core 6”) 15-20dB 15% 150ft. (50m)
Very Heavy Wall (solid core 12”) 20-25dB 10% 100ft. (30m)
Floor/Ceiling (solid core) 15-20dB 15% 150ft. (50m)
Floor/Ceiling (heavy solid core)
20-25dB 10% 100ft. (30m)
Note:
Take stairwells and elevator shafts into consideration when positioning Access
Points. There is no way to quantify the loss associated with these obstructions,
however they do have an effect on the signal.