Innovative Cisco Wireless Location Appliance: The Right Tools to Visualize and Control RF Domains
May 4, 2005
By Jenny Carless, News@Cisco
Mobility makes life easier in many ways, and today millions take for granted the flexibility and freedom that wireless networks bring to their lives. From easy network access for enterprise users to consumers in coffee shops and hotels to radio frequency identification (RFID) tags that help manufacturers manage inventory, wireless networks and the applications that run on them help customers create a more agile, efficient and collaborative work environment.
But mobility can also introduce security and management headaches. So enterprises that want to reap the benefits of mobility fully need the right tools to visualize - and control - their RF domains and networks. Location tracking is becoming an essential component in enterprise networking because it brings that critical visibility and control to wireless local area networks (WLANs).
Innovation in Wireless Location Tracking
The industry-leading Cisco Wireless Location Appliance provides integrated, highly accurate location tracking capabilities that can scale to support thousands of simultaneous devices.
It helps enable businesses of all sizes to track any mobile device, from wireless laptops and PDAs to devices equipped with IEEE 802.11 RFID tags and can be used for asset tracking, inventory management, workflow automation, emergency 911 services and tighter WLAN security. The appliance is also equipped with application programming interfaces (APIs) that tightly integrate the company's advanced location services with external software tools.
The Cisco Wireless Location Appliance brings a host of tangible benefits to enterprises running business critical wireless LANs, including accuracy, scalability, smooth integration, automated workflow and flexibility.
"It all started with the need to detect rogues on the network," explains Allan Thomson, Technical Lead at Cisco for the Wireless Networking Business Unit's Wireless Location Appliance and related technology. "At Airespace (recently acquired by Cisco), we wanted a scalable server-based location product, so we started developing designs and specifications around that."
The technology has gone through three developmental stages, according to Thomson, a 20-year networking veteran who served as technical lead from the product's inception through its recent release.
"When we began, the simplest way to perform location tracking in a WLAN environment was to determine the closest access point (AP) to a wireless device," he says. "But while it was easy to do, that method lacked granularity."
"We then experimented with RF triangulation as means to provide better location, which improved results but still did not provide the accuracy we were looking for," Thomson continues. Triangulation involves calculating the location of a device based upon the detected signal strength of nearby APs. The data from each AP are cross-referenced in order to hone in on the location of the desired device. But RF triangulation still has limitations: the fact that a wireless client can be 'heard' more easily behind wood than a concrete wall, for example, can skew results, which impacts overall effectiveness.
Thomson and his colleagues eventually arrived at RF fingerprinting, the innovative location tracking technique used in the new Cisco Wireless Location Appliance.
The appliance's patent-pending RF fingerprinting technology can determine the location of a wireless client to within a few meters by correlating known RF characteristics of a building with real-time user and mobile device information. RF fingerprinting combined with the appliance can build a system to track thousands of wireless clients simultaneously, helping to ensure that location services can be applied to an entire enterprise environment.
"This technique compares a client's view of the network infrastructure with a database that contains an RF physical model of the coverage area," Thomson explains. "By calibrating the air space, RF fingerprinting provides very accurate location tracking results, typically within a few meters."
Cisco integrates location tracking directly into the WLAN infrastructure. For example, the same Cisco APs that are delivering traffic are also used to locate wireless devices. This minimizes capital expenditures, helps ensure better visibility and helps enable the WLAN itself to act upon location information for better security and capacity management.
The Cisco Wireless Location Appliance also offers a robust set of APIs that help tie it to external systems for enhanced functionality and automated workflow.
Multiple Applications
As the Cisco Wireless Location Appliance was developed, Thomson and his team began to identify a host of potential applications beyond the original goal of rogue detection. "Often a project starts with an initial business need, but then you realize that it can be reused or applied to different needs," Thomson explains.
In its final form, the Cisco Wireless Location Appliance can be used in a range of ways for improved WLAN security and network control as well as visibility and tracking.
In addition to identifying rogue access points, the new appliance can be used to track people - such as children in an amusement park or patients in a hospital - as well as to locate and track valuable equipment like shipping containers, vehicles and medical equipment. Further, automatic alarms help IT staff detect the removal of mobile devices from authorized premises.
Cisco continues to focus on the integration of wired and wireless networking for the benefit of improved enterprise-wide security, management and support for new applications such as location services. With business-critical WLAN products and services from Cisco, customers can be confident that their existing network investments are future-proofed and will continue adding value over time.
Jenny Carless is a freelance writer based in Santa Cruz, CA.
