Руководство По Проектированию для Cisco Cisco Aironet 350 Mini-PCI Wireless LAN Client Adapter
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Enterprise Mobility 4.1 Design Guide
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Chapter 13 Cisco Unified Wireless Location-Based Services
Cisco Location-Based Services Architecture
An RTLS system designer can choose to implement one or more of these techniques. This may clearly
be seen in some approaches attempting to optimize performance in two or more environments with very
different propagation characteristics. It is not unusual to hear arguments supporting the case for a fifth
category that encompasses RTLS systems that sense and measure position using a combination of at least
two of these methods.
be seen in some approaches attempting to optimize performance in two or more environments with very
different propagation characteristics. It is not unusual to hear arguments supporting the case for a fifth
category that encompasses RTLS systems that sense and measure position using a combination of at least
two of these methods.
Keep in mind that regardless of the underlying positioning technology, the “real-time” nature of an
RTLS is only as real-time as its most current timestamps, signal strength readings, or angle-of-incidence
measurements. The timing of probe responses, tag beacons, and location server polling intervals can
introduce discrepancies between the actual and reported device position observed during each reporting
interval.
RTLS is only as real-time as its most current timestamps, signal strength readings, or angle-of-incidence
measurements. The timing of probe responses, tag beacons, and location server polling intervals can
introduce discrepancies between the actual and reported device position observed during each reporting
interval.
The “Location Tracking Approaches” section of Wi-Fi Location-Based Services: Design and
Deployment Considerations provides a foundation in the technical aspects of traditional location
tracking and positioning systems. This section is recommended reading for a better understanding of the
differences between traditional approaches and RF Fingerprinting. It thoroughly explains the concepts
of cell of origin, time of arrival (ToA), time difference of arrival (TDoA), angle of arrival (AoA), and
location patterning.
Deployment Considerations provides a foundation in the technical aspects of traditional location
tracking and positioning systems. This section is recommended reading for a better understanding of the
differences between traditional approaches and RF Fingerprinting. It thoroughly explains the concepts
of cell of origin, time of arrival (ToA), time difference of arrival (TDoA), angle of arrival (AoA), and
location patterning.
What is RF Fingerprinting?
Cisco RF Fingerprinting refers to an innovative localization approach that significantly improves the
accuracy and precision over that available from traditional signal strength lateration techniques. Cisco
RF Fingerprinting offers the simplicity of an received signal strength indication (RSSI)-based lateration
approach with customized calibration capabilities and improved performance over traditional
approaches.
accuracy and precision over that available from traditional signal strength lateration techniques. Cisco
RF Fingerprinting offers the simplicity of an received signal strength indication (RSSI)-based lateration
approach with customized calibration capabilities and improved performance over traditional
approaches.
RF Fingerprinting significantly enhances received signal strength (RSS) lateration through the use of RF
propagation models developed from data gathered in the target or similar environments. RF
Fingerprinting offers the ability to calibrate an RF model to a particular environment in a fashion
analogous to (but more expeditious than) that of location patterning. But unlike location patterning, RF
Fingerprinting allows for the reuse of calibration models in situations where multiple floors of similar
construction, contents, and layout are deployed.
propagation models developed from data gathered in the target or similar environments. RF
Fingerprinting offers the ability to calibrate an RF model to a particular environment in a fashion
analogous to (but more expeditious than) that of location patterning. But unlike location patterning, RF
Fingerprinting allows for the reuse of calibration models in situations where multiple floors of similar
construction, contents, and layout are deployed.
In addition, Cisco RF Fingerprinting offers the following key advantages over the traditional approaches
described in the “Location Tracking Approaches” section of Wi-Fi Location-Based Services: Design and
Deployment Considerations:
described in the “Location Tracking Approaches” section of Wi-Fi Location-Based Services: Design and
Deployment Considerations:
•
Uses existing LWAPP-enabled Cisco Unified Networking components—Unlike some other
solutions, the location-aware Cisco UWN with RF Fingerprinting does not require added-cost
specialized receivers or other hardware that must be mounted alongside each access point. This
helps keep the capital and ongoing maintenance costs of the location-aware Cisco UWN low in
comparison to solutions requiring a dedicated overlay location infrastructure. The Cisco Location
Appliance is added as a centralized component to support location and statistics history and serves
as a location positioning engine for the simultaneous tracking of up to 2500 devices per appliance.
solutions, the location-aware Cisco UWN with RF Fingerprinting does not require added-cost
specialized receivers or other hardware that must be mounted alongside each access point. This
helps keep the capital and ongoing maintenance costs of the location-aware Cisco UWN low in
comparison to solutions requiring a dedicated overlay location infrastructure. The Cisco Location
Appliance is added as a centralized component to support location and statistics history and serves
as a location positioning engine for the simultaneous tracking of up to 2500 devices per appliance.
•
No proprietary client hardware or software required—Location-based services in the Cisco UWN
are implemented as a network-side model, not client-side. Because of this, Cisco RF Fingerprinting
can provide location tracking for a wide variety of industry-standard Wi-Fi clients without the need
to load proprietary tracking software or location-enabling drivers in each client. Any IEEE 802.11
client can be located in most cases, with WLAN enhanced client localization for clients compatible
with the Cisco Compatible Extensions for WLAN clients specification version 2 or higher. This
includes popular VoWLAN handsets such as the Cisco 792x series and others for which proprietary
location tracking client software is neither readily available or installable.
are implemented as a network-side model, not client-side. Because of this, Cisco RF Fingerprinting
can provide location tracking for a wide variety of industry-standard Wi-Fi clients without the need
to load proprietary tracking software or location-enabling drivers in each client. Any IEEE 802.11
client can be located in most cases, with WLAN enhanced client localization for clients compatible
with the Cisco Compatible Extensions for WLAN clients specification version 2 or higher. This
includes popular VoWLAN handsets such as the Cisco 792x series and others for which proprietary
location tracking client software is neither readily available or installable.