Where's Wi-Fi Waldo?
A White Paper on Location-Based Services
Dennis Nofsinger, Senior Wireless
Training Specialist, CCSI, CCNA and CCNA Wireless
Abstract
Physically keeping track of all of your expensive mobile assets
is very inefficient, time-consuming, and often results in missing
mobile assets, which are unaccounted for. Cisco has a
location-aware solution that puts an end to this daunting task.
Using Cisco's Wireless Control System (WCS), controller-based
access points, Cisco 3300 Series Mobility Service Engine, and Cisco
compatible radio frequency identification (RFID) tags, you can
locate your mobile assets by looking at a digitized version of your
floor plan. You will see an icon representing the device(s) you are
tracking displayed right on your floor, and the accuracy is very
impressive. Cisco's location-aware devices and RFID tag partners
can also extract location data from your mobile assets.
Introduction
I remember playing a game when I was younger named Where's
Waldo? The objective of this game is to find the cartoon character,
named Waldo, in a crowded and busy environment, like an amusement
park. At first, you think this will be easy, because Waldo always
wears his signature red and white striped shirt, blue pants, and
black round glasses. The illustrator of Where's Waldo would go to
great lengths to hide Waldo from you. So your search for Waldo
takes more time than you ever expected. Eventually, you would spot
Waldo standing by the double-loop roller coaster, eating a
raspberry snow cone, and the game is over.
Physically keeping track of all of your expensive mobile assets
can be like playing a real world version of Where's Waldo. The
object of this game is for you to do a physical floor-by-floor
search, looking for these devices without loosing your mind. This
physical procedure is very inefficient, time consuming, and often
results in missing mobile assets, which are unaccounted for.
Cisco has a location-aware solution that puts an end to this
daunting task. This solution consists of Cisco's Wireless Control
System (WCS), controller-based access points, Cisco 3300 Series
Mobility Service Engine, and Cisco compatible radio frequency
identification (RFID) tags. These location-aware devices will
enable you to play a high-tech version of Where's Waldo, which I
like to call "Where's Wi-Fi Waldo." By using Cisco WCS, you can
locate your mobile assets by looking at a digitized version of your
floor plan. You will see an icon that represents the device or
devices you are tracking displayed right on your floor and the
accuracy is very impressive. If the mobile asset you want to track
does not have an imbedded radio, for example a wheel chair, simply
attach an active RFID tag to it and you are all set. Currently,
802.11 active RFID tags are designed to operate in the 2.4-GHz
(802.11b) radio band. Cisco's location-aware devices and RFID tag
partners can also extract location data from your mobile assets.
Valuable information like: where is it now (location tracking
services), where has it been (location tracking history), how long
did it take to get there (assembly line material in process), has
it left a secured area (chokepoints), and even the temperature
around the specialized RFID tag (hourly temperature monitoring of
hospital refrigerators and freezers).
The objective of this document is to help you have a better
understanding of what is required to design and implement an indoor
location-aware network. The topics covered in this document
are:
- Proper Access Point Positioning
- Viewing Location Information
- The Heart of Real-Time Location Tracking
Proper Access Point Positioning
The main contributing factor to unacceptable wireless LAN (WLAN)
performance is poor access point positioning (separation).
Performing a site survey that focuses on the main WLAN application,
for example Voice over Wireless LAN (VoWLAN), is the keystone of a
successful WLAN installation.
To help illustrate why proper access point positioning is
essential, a little WLAN history is in order. In the early 1990's,
indoor WLAN deployments started to emerge in warehouses,
distribution centers, and factories. This was due to the new
business paradigm called "Just in Time." This new shift in the way
inventory was managed required companies to invest into wireless
inventory systems. At that time, many 2.4 GHz wireless solutions
were available, but they all were proprietary and that locked a
company into a one vendor solution.
In 1997, wireless interoperability went from an idea to reality
thanks to the ratification of IEEE 802.11. This generated a renewed
interest in the use of Star Trek looking wireless handheld devices.
These devices contained a laser for reading barcodes and a wireless
802.11 radio to transmit data in real-time conditions. Main frame
emulation software was the most common application these devices
ran, making the 802.11 wireless devices a perfect fit using 1 to 2
Mbps data rates. The proper access point positioning for 802.11
data collection devices works out to be approximately 200 to 275
feet. Of course, this all depends on the condition of the indoor
environment, which may cause distances to vary. By determining the
correct access point positioning, data collection devices could
seamlessly roam throughout millions of square feet without
disruption to the client emulation application.
Related Courses
Cisco Unified Wireless Networking (CUWN)
Cisco Wireless LAN Advanced Topics (CWLAT)
Cisco Wireless LAN Fundamentals (CWLF)
Implementing Unified Wireless Networking Essentials (IUWNE)