Wi-Fi Real-Time Location Services

Wi-Fi-based RTLS systems track people and assets using 802.11-based clients equipped with location software and smart Wi-Fi asset tags. Today's systems are built on standard 802.11 network infrastructure but rely on proprietary elements that limit interoperability. Efforts under way in the IEEE 802.11k and 802.11v working groups promise to increase the sophistication and interoperability of location services using conventional 802.11 clients. AeroScout introduced the first Wi-Fi-based active RFID tag in 2003. Aruba Networks is a leading advocate of dense AP deployment, partnering with Newbury Networks, as well as Ekahau and PanGo Networks, both providers of Wi-Fi location tags. Cisco bills its 2710 Wireless Location Appliance as the first location solution that simultaneously tracks thousands of devices from within the WLAN infrastructure. Ekahau offers sophisticated location tracking capabilities, built on its WLAN design and modeling tools. RTLS products are of greatest appeal to enterprises with expensive mobile assets. As standards emerge and hardware and software costs decline, it will likely experience greater penetration in horizontal markets, particularly at companies with high security requirements and those deploying wireless VoIP or presence-based applications.

Proprietary wireless real-time location services have been available to enterprises for years. Newer systems based on passive RFID technology also have garnered significant attention, especially for supply-chain applications where products are tracked. But some of the most interesting RTLS systems are being built on top of emerging Wi-Fi networks, with considerable success. Pending standards work on 802.11k and 802.11v will improve the interoperability of location services using conventional clients; such work--along with the increased use of Wi-Fi location tags, or "active RFID tags"--will help to drive adoption of RTLS systems from niche uses to a broader horizontal market.

Standards for location services are only beginning to gain attention, but the work under way in the IEEE 802.11k and 802.11v task groups will allow for more sophisticated Wi-Fi location capabilities. 802.11k will define and expose radio and network information to facilitate the management and maintenance of a wireless LAN. This will standardize some basic radio information required to support standards-based location tracking. 802.11v will provide extensions to the 802.11 PHY and MAC standards to improve management capabilities of WLAN clients.

Among vertical industries, Wi-Fi RTLS providers have focused in particular on the health-care market. Many hospitals are using inexpensive Wi-Fi location tags, attached to equipment, to track valued assets, including mobile diagnostic equipment that can be difficult to locate when needed.