Wi Lan Inc EB02 Benutzerhandbuch
APR 2001 Rev 03
111
Appendix A: Planning Your Wireless Link
To ensure an effective and reliable wireless link, you first need to perform some network planning. This
section provides some general guidelines for planning a wireless link, including the following:
section provides some general guidelines for planning a wireless link, including the following:
•
Planning the physical layout of your system
•
Determining antenna and cable requirements
•
Determining configuration settings for units
•
Calculating a link budget
Planning the Physical Layout
You need to plan the physical layout of your wireless system.
•
Determine the number of remotes
•
Ensure LOS (line-of-sight) exists between units and determine coverage areas
•
Measure the distance between the base station and each remote unit
•
Consider the need for equipment shelters, electrical power and environmental requirements
Determine the Number of Remotes
Since the 12 Mbps data rate is shared between all units, the fewer the number of remote units, the faster each
wireless link. Although a maximum of 1000 remotes is supported per base station, this number would result
in low data rates. Instead, to ensure high data rates, Wi-LAN suggests a standard where 75 remotes can
maintain constant 128 kbps communication with a base station. Since it is unlikely that all units will be active
at the same time, the total number of remotes for planning purposes can be increased by a factor of three, so
that a maximum of 225 (3 x 75) remotes per base station is recommended. This should enable all users to
easily achieve 128 kbps performance.
wireless link. Although a maximum of 1000 remotes is supported per base station, this number would result
in low data rates. Instead, to ensure high data rates, Wi-LAN suggests a standard where 75 remotes can
maintain constant 128 kbps communication with a base station. Since it is unlikely that all units will be active
at the same time, the total number of remotes for planning purposes can be increased by a factor of three, so
that a maximum of 225 (3 x 75) remotes per base station is recommended. This should enable all users to
easily achieve 128 kbps performance.
Ensure LOS and Determine Coverage Area
Ensure the availability of a clear, LOS (line-of-sight) radio path between base station and all its remotes. Plot
the coverage area of each base station on a map, and determine which base station will service which remote
unit. Plan some alternate links in case base station coverage areas overlap or if physical obstacles block the
radio path to some remotes.
the coverage area of each base station on a map, and determine which base station will service which remote
unit. Plan some alternate links in case base station coverage areas overlap or if physical obstacles block the
radio path to some remotes.