Installation guide
45
Wi-Fi Location-Based Services—Design and Deployment Considerations
OL-11612-01
Installation and Configuration
Configuring Location Server Location Parameters
The configuration of Location Server > Administration > Location Parameters is discussed in Cisco
Wireless Location Appliance Configuration Guide: Editing Location Parameters at the following URL:
http://www.cisco.com/en/US/products/ps6386/products_configuration_guide_chapter09186a00806b5b
10.html#wp1046431.
Further clarification regarding some of these parameters is provided in subsequent sections.
Enable Calculation Time
The “enable calculation time” location parameter refers to an advanced debugging option that enables
logging of the amount of time that internal localization calculations consume. It is disabled by default
and should be enabled only on the recommendation of the Cisco Technical Assistance Center (TAC) or
Cisco Engineering, because it adds overhead to the overall location calculation.
Enable OW Location
This parameter was intended to allow obstacles and heavy wall attenuation values to be factored into the
positioning algorithm by the location server. The location appliance uses up to 50 heavy walls that have
been defined in the WCS Map Editor when evaluating path loss models and conducting positioning
calculations. Heavy walls are those defined in the Map Editor with attenuation values of 13 dB.
In Release 4.0, Enable OW Location has been superseded by a more advanced technique where the
location server decides whether location accuracy would be improved or degraded by the inclusion of
any heavy walls that are defined via the Map Editor (Monitor > Maps > Properties >Wall Usage
Calibration). When set to Auto, the location appliance dynamically establishes whether the inclusion of
heavy walls in the calibration would improve location accuracy. The use of heavy walls can be forced by
setting this parameter to “Use Walls” or disabled by setting it to “Do Not Use Walls”.
“Enable OW Location” is disabled by default, and Cisco recommends that it be kept in the disabled state
unless instructed otherwise by Cisco TAC.
RSSI Discard Times
• Relative RSSI Discard Time—This parameter denotes the relative boundary of RSSI sample times
used in location calculations. It specifies the time between the most recent RSS sample and the
oldest usable RSS sample. The default relative RSSI discard time is 3 minutes. During normal
operation of the location appliance, this parameter should be left at the default value and should not
changed except on the advice and recommendation of the Cisco Technical Assistance Center (TAC)
or Cisco Engineering.
• Absolute RSSI Discard Time—This parameter denotes the absolute boundary of RSSI sample times
used in location calculations. The default is 60 minutes, which means that RSSI samples older than
60 minutes are not used in location calculations, regardless of relative RSSI discard time. During
normal operation of the location appliance, this parameter should be left at the default value and
should not be changed except on advice of the Cisco Technical Assistance Center (TAC) or Cisco
Engineering.