User's Manual
Table Of Contents
- Purpose
- Targeted Audience
- Referenced Documentation
- Conventions
- Human Exposure to Radio Frequencies
- Radio Interference
- Avoiding Radio Interference
- Modifications
- General
- Manufacturer's Disclaimer Statement
- European Community, Switzerland, Norway, Iceland, and Liecht
- Declaration of Conformity with Regard to the R&TTE Directive
- ProST Frequency Ranges
- Main Features
- Architecture
- ProST Protocol Stack
- Theory of Operation
- Package Contents
- Minimum PC Requirements
- Required Tools
- Radio Site Planning
- ProST Physical Description
- SDA-1 Physical Description
- SDA-4S Type II and SDA-4S/VL Type II (Optional)
- Mounting the ProST
- Wall Mounting
- Pole Mounting
- SDA-4S
- Connecting to IDU
- Connecting to LAN Network
- Connecting AC/DC Power Adapter
- Mounting AC/DC Power Adapter
- DC Power Source
- AC Power Source
- Connecting Lightning and Surge Protector
- Antenna Alignment using RSSI LED Plug Adapter
- LED Status
- 1. Disclaimer
- 1.1 Safety Warnings
- 1.2 Important Warning Symbols
- 1.3 Important Service Information
- 1.4 UL Information
- 1.5 CE Notice
- 1.6 European Community, Switzerland, Norway, Iceland, and L
- 1.7 CAUTION
- 1.8 Lightning Protection
Installation Prerequisites
13
Fresnel Zones define the amount of clearance required from obstacles. These zones are
composed of concentric ellipsoid areas surrounding the straight-line path between two
antennas. Thus, the zone affects objects to the side of the path and those directly in the path.
The first Fresnel Zone is the surface containing every point for which the distance from the
transmitter to any reflection point on the surface point and then onto the receiver is one-half
wavelength longer than the direct signal path.
One method for clearing the Fresnel Zone is by increasing the antenna height.
The first Fresnel Zone radius is calculated by the following equation:
Where f is the frequency (in MHz) and d is the distance (in meters) between the ProST and the
base station.
For example, using the formula above, a link of 4 km at 700 MHz produces a first Fresnel Zone
radius clearance of about 20 meters. This implies that to ensure the ground does not enter into
the first Fresnel Zone, both antennas (i.e. at Base Station and subscriber) must be mounted at
least 20 meters above ground level (or clutter level). Typically, at least 60% clearance of the
first Fresnel Zone is considered as LOS. Therefore, in the above example, a height of at least
12 meters (i.e. 60% of 20 meters) above ground level is sufficient for LOS.
Multipath Fading
Some of the transmitted signals may be reflected from a nearby building, by water under the
signal path, or from any other reflectors. This reflected ("bounced") signal can then be received
by the radio receiving the signal and superimposed on the main received signal, thereby
degrading the signal strength.
To avoid multipath fading from nearby buildings etc., Airspan recommends installing the
outdoor radios at the rear end of the buildings instead of at the front. When you install at the
rear end of the building, the front-end of the building blocks incoming signals from multipath
reflections.
Radio Antenna Alignment
Once the ProST is installed and aimed in the general direction of the base station, it is
recommended to measure the received signal strength (RSS) to determine the signal strength
received from the base station, and to precisely align the ProST for maximum signal strength.
You need to orientate (up/down, left/right) the ProST until the maximum RSSI levels are