Installation guide

51
Wi-Fi Location-Based Services—Design and Deployment Considerations
OL-11612-01
Deployment Best Practices
Shutting down audit subsystem[ OK ]
Starting killall: [ OK ]
Sending all processes the TERM signal...
Sending all processes the KILL signal...
Syncing hardware clock to system time
Turning off swap:
Turning off quotas:
Unmounting file systems:
Halting system...
md: stopping all md devices.
flushing ide devices:
Power down.
Note that issuing the shutdown command from a remote SSH client results in your SSH session
becoming disconnected. The Linux operating system of the location appliance still initiates the
shutdown procedure; however, your session becomes disconnected before the command completes.
Therefore, you are not able to view all the command output as you would on a CLI console device. To
avoid this lack of visibility, Cisco recommends that a terminal or PC attached to the location server
console terminal be used to perform this task rather than an SSH session if possible.
Step 3 The final step is to remove power to the location appliance by using the front panel ON/OFF switch to
turn the location appliance off. This should be done after the “power down” message is seen on the CLI
console (shown in bold above). Note that if using a remote SSH session, you do not see the “power
down” message because your session was disconnected shortly after issuing the shutdown command. In
this case, you should wait approximately two minutes for the shutdown command to complete before
removing power to the location appliance using the front panel ON/OFF switch.
Deployment Best Practices
“Location-Aware” WLAN Design Considerations
In the past decade, the design of enterprise-ready wireless LANs has evolved from being centered around
the model of maximum coverage with minimum AP count to a model where coverage uniformity and
proper cell-to-cell overlap are the predominant concerns. This has been driven by increasing interest in
deploying new wireless applications such as wireless voice with its intolerance for large amounts of
dropped packets and high roaming delays. In a similar fashion, deploying location-based applications
using a Wi-Fi wireless LAN requires a modification of the current approach, both in how you design new
“location-aware” installations and also in how you augment or retrofit existing designs to take advantage
of location-tracking applications. To facilitate optimal location tracking performance, the correct
number of access points along with proper access point placement is necessary.
Minimum Signal Level Thresholds
For mobile devices to be tracked properly, a minimum of three access points (with four or more preferred
for better accuracy and precision) should be reporting detected signal strength for any device being
tracked. This detected and reported RSSI should be at the level of the RSSI cutoff or better.
Note As of release 4.0.155.0 of WLAN controller software, each tracked entity (WLAN client, RFID tag,
rogue access point, or rogue client) is detected by a maximum of eight registered infrastructure access
points at any time on each WLAN controller.