Asset management has long been a popular application for RFID, but some new wireless technologies are beginning to emerge that both compete with and complement RFID in asset tracking environments.

Traditionally, wireless asset tracking applications have been served by active RFID tags or real-time location systems (RTLS) that use Wi-Fi (802.11) or proprietary technology.

More recently, the wireless mesh networking technology ZigBee has gained some ground in typical RFID or RTLS applications. RuBee, a wireless technology that leverages magnetic waves, is being utilized for asset tracking, and Ultra-Wideband (UWB) systems are also emerging in the space.

This multitude of wireless options has developed because users have realized that it will require a mix of technologies to meet all of their tracking needs. "We have gotten too hung up on specific technologies," says Joe Barkai, practice director at IDC's Manufacturing Insights. "The way to look at this space is, once we have an enabling technology, does it offer a new model for service? Is there a value to be derived from it?"

ZigBee is a wireless protocol built on the existing IEEE 802.15.4 standard that can be used to set up wireless personal area networks that allow devices (including sensors) to "talk" to each other. The range of these systems is typically around 10 meters

It is also increasingly used in asset tracking applications. Saint Luke's East-Lee's Summit Hospital in Missouri, for instance, tested a system from InnerWireless, McKesson and PanGo Networks that uses ZigBee devices to track patients and medical equipment.

"We sat down with our healthcare advisory board a few years ago, and basically they said that there were all these location products out there, but all of them were really missing the mark," says Kevin Swank, director of product marketing at InnerWireless. "802.11 systems allow them to re-use their existing infrastructure, but they didn't provide the accuracy they wanted. The room-level technologies were accurate, but they were incredibly expensive to install."

Although ZigBee has lower data rates and bandwidth than traditional RFID, it can provide more granular location data. InnerWireless developed its SPOT product using ZigBee technology (although not utilizing the mesh networking portion of the standard), which provides room-level asset location accuracy, but doesn't require extensive infrastructure wiring. The system uses battery operated "beacons" to track ZigBee-based tags. The beacons then communicate back to master radios (which are similar to access points in a traditional wireless system).

InnerWireless recently merged with PanGo, which provides a multi-technology middleware product that can support a variety of tag technologies.

"There will be a mix of technologies in hospitals," says Swank. "There will be a mix of zone- and room-level systems."

ZigBee use across applications is growing. ON World predicts that by 2011, global revenues for wireless sensor networks will reach $2.6 billion, with 25% of commercial building energy reduction attributed to such networks by 2013 (around $7.4 billion in global energy savings). These savings stem from better equipment monitoring and utilization, which can improve energy efficiency.

ZigBee can be used for wireless control and monitoring solutions like those offered by Synapse and MeshNetics. Wireless sensor networks using ZigBee technology can also be used to monitor logistics assets. Bulldog Technologies, for instance, has developed a wireless sensor system that can collect temperature data from refrigerated trucks, produce containers and grocery store coolers.

"The ability to connect fixed assets to a back-office application, whether by RF or even a wired connection, present an opportunity to better manage the capacity of your equipment, and to understand utilization and failure rates," says Barkai.

According to ABI Research, the commercial building market is where ZigBee stands to have the most growth, and where it has the best competitive position against other wireless sensor technologies. Most of the major building automation system providers (Johnson Controls, Honeywell, Siemens, TAC and Trane) have already introduced or are planning to introduce ZigBee products.

An advantage that ZigBee has in these commercial building applications is that ZigBee nodes can create impromptu networks for transferring data, which saves a significant amount of infrastructure work.

"Commercial buildings represent a huge addressable market of field equipment currently using wired field buses to connect sensors and actuators with lighting, heating, ventilation, access control, and safety systems," says Sam Lucero, ABI senior analyst. "ZigBee's features and functionality are very well suited to commercial building applications."

Further, In-Stat found that between 4.5 million and 10.5 million ZigBee components were expected to be sold last year, and that commercial building control was the largest 802.15.4/ZigBee application.

UWB

UltraWideband technology (UWB) was originally developed by the military, and cleared for commercial use in the U.S. in 2002. UWB tags emit a series of short pulses across a frequency segment that is wider than the one used by conventional RFID tags.

UWB asset tracking applications have been emerging in recent years. Parco Wireless, for example, deployed a UWB system for tracking patients, staff and equipment at Washington Hospital Center in Washington, D.C., in 2004. This past spring, the hospital announced plans to expand its deployment from 700 tags to more than 2,500 tags. Lehigh Valley Hospital and Health Network in Pennsylvania is deploying a system from Patient Care Technology Systems for patient tracking, using Parco tags.

Only a few UWB products have come to market so far, and there are concerns about potential interference issues once more users begin utilizing the spectrum. The European Commission (EC) formally adopted a UWB frequency range earlier this year that could increase use of these systems in Europe.

RuBee

Another technology, dubbed RuBee, has also found a niche in applications where traditional RFID is not as effective. The technology was introduced by Miami-based Visible Assets, and is based on 132 kHz technology.

RuBee primarily uses magnetic waves to transmit a signal, so it is less prone to interference from metal or liquids. Although fewer tags can be read per second than high-frequency RFID or UHF RFID, the tags work well for tracking high-value assets. Battery life is 10 years, with a read range that can span from 8 to 20 feet. According to the company, that range can be extended even further (to more than 50 feet) in some conditions.

"RuBee has an interesting, almost disruptive nature," says Barkai. "I saw a demonstration of it. You can take a tag and dump it into a container full of water, and they were able to read it. The signal strength was lower, but they could read it. You can look at areas where RFID tags are not necessarily useful, and see where this adds value."

Visible Assets promotes the concept of "RF Feng Shui," meaning that everything within a room or facility impacts the performance of wireless system, not just the tags and readers.

"The best feng shui in a room is at 132 kHz," says John Stevens, chairman of Visible Assets. "That's where everything likes to vibrate. All metal vibrates there. This is really a magnetic signal, not a radio signal. As a result, we're doing a lot of work with the government in high-security areas, where you don't want a radio signal leaking out of the area."

Currently, Visible Assets has deployed livestock tracking solutions, asset tracking systems in the healthcare industry, and personnel and asset tracking solutions for a variety of government agencies. In livestock tracking (an area where RFID has been in use for several years), Stevens says the company has achieved read ranges of up to 100 feet, and signals from the tags are not blocked by water or moisture within the tagged animals, as is the case with other wireless systems.

RuBee has a slower read rate than RFID, but Stevens says that this is not particularly relevant for practical applications like asset tracking.

"We're not going to discover 200 tags on a pallet moving at six miles per hour," Stevens says. "We can't do that. But, frankly, nobody else can do that either. These flying carpet specifications have gotten us all in a lot of trouble in the past. We can read 20 tags going six miles per hour -- that's a real-life situation, and a commercial opportunity."

The IEEE now has a working group (P1902.1) to develop RuBee into a standard, and the initial specification was passed earlier this year.

Even with these new technologies, Barkai says that business process improvement is the key to gaining a return on investment from wireless asset tracking and maintenance applications. "We did a study on the automotive space, and even though many companies are using different technologies to tag parts and subsystems, in most cases the business process was the same as the old process," Barkai says. "Those systems were not highly optimized or effective. It's not enough for a technology to just be cool any more. Someone has to really see the value and be willing to invest not only the funds for these systems, but also invest in changing the business process."

 These technologies and more will be discussed at the 2008 Asset Management Conference & Expo, January 22-23, 2008, in Atlanta, Ga. For more information, visit www.AssetExpo.com.